text:
Audax on support Arctic expedition
Audax, the world's first polar class heavy transport deck carrier manufactured by the Netherlands-based ZPMC-Red Box company, is sailing on icy water for the world's largest Liquefied Natural Gas (LNG) project.
The Audax arrives in the Port of Sabetta on Russian Yamal Peninsula after an eight-day voyage from Belgium. With a maximum load of 28,500 tons, the 206.3-meter icebreaker is transporting large modules for the construction of the world's largest Liquefied Natural Gas (LNG) production project in Yamal. When the project starts operations in 2017, the oil and gas reserves that have been buried under the Arctic ice for millions of years will be ready to be explored and developed by humans.
The Audax is currently one of the only two transport deck carriers in the world that can transport cargo in the Arctic region around the year. Powered by Siemens' advanced electric propulsion system that optimizes energy efficiency, it plays a crucial role in the construction of this LNG project.
Smashing through ice
As the world's first polar class heavy transport deck carrier capable of breaking ice up to 1.5 meters thick, the Audax can carry two large 10,000-ton modules at the same time and travel at a speed of 2 knots, or about 3.8km/h, through the ice. The construction of the Yamal LNG project basically depends on Audax and its sister vessel, the Pugnax. Both of them serve by transporting the modules for the project.
From power generation and power distribution to drives, Siemens electric propulsion system helps the Audax handle the daunting challenges posed by the harsh polar environment in a powerful and energy-efficient way.
"The biggest challenge to the electric propulsion system is the instant large torque fluctuations when the vessel is running in ice conditions," said Erik-John Gerssen, Audax's chief engineer. "The propulsion motors are specially designed to meet the mechanical stress caused by these high torque fluctuations." In other words, in the icy Arctic waters where the propeller blades may be confronted with hundreds of tons of impact force, the Siemens propulsion motors can continuously output sufficient power to ensure that the vessel can overcome obstacles and progress smoothly through the packed ice.
In the Siemens electric propulsion system, two 8 MW and two 7.6 MW generators continuously provide stable power to the carrier. The transformers convert the power into voltages suitable for the drive system and other equipment. In addition, the low and medium voltage distribution panels provide safe and efficient power transmission and distribution. The two main propulsion drives and two 12 MW propulsion motors work together perfectly to meet different power requirements during ice-breaking and normal navigation.
"Besides the mechanical aspects of these torque fluctuations, also the electrical effects need to be considered in the power grid. Therefore the propulsion drives are controlled by special software and the power management system is extended with special features to ensure a stable power supply," Gerssen said.
Audax is equipped with the Siemens Power Management System (PMS). It optimizes power distribution to achieve the highest efficiency and maintain the most economical operating status for the vessel. In extreme situations it distributes the power to critical equipment to ensure the ship's operating stability.
During the voyage, the operating status of all systems on board, like mechanical equipment and fuel, are constantly transparent and controllable. The Siemens Siship, based on the Totally Integrated Automation (TIA), collects and monitors the operating parameters of each system in real time to inform the captain on the bridge. The integrated Siemens Siship electric propulsion system helps the Audax improve overall efficiency and reliability and reduce fuel consumption, thus lowering operating costs.
If any equipment on the Audax when it is in the Arctic Ocean has problems, Siemens engineers in Shanghai can diagnose these remotely via the Internet, solve problems as early as possible and, in turn, ensure equipment availability and ship safety. The remote diagnosis system mainly achieves two functions: hardware diagnosis and remote software operation interface modification. If the crew detects a problem, Siemens engineers can read the diagnostic information by logging on to their computers.
"With the remote diagnosis service, problems can be solved promptly. So our customers are satisfied and we are happy," said Shi Qinghua, team leader of the remote diagnosis service at Oil and Gas and Marine Technology, Process Industries and Drives Division, Siemens Ltd., China.
Over the years, new technologies have been developed and implemented for the polar icebreaker carriers. Siemens pays close attention to development of new technologies and actively provides advanced power systems for the ships. Siemens has followed up on these new developments actively and developed new electric solutions for this kind of vessel. "This project sets a new benchmark for the application of the Siemens propulsion system for polar vessels. Starting with the polar class heavy transport deck carriers, Siemens has implemented state-of-the-art technology to achieve the highest reliability, efficiency and availability. Also Siemens has made new contributions to the exploration and development of resources in polar regions," said Hu Xiangdong, head of Marine Solution, Process Industries and Drives Division, Siemens Ltd., China.
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Your internet guide to
all things catfish
Brackish Water Catfish
Dr. Neale Monks
Neale Monks is editor and senior author of Brackish Water Fishes, published by TFH and due out this summer (2006). He is the brackish water 'expert' in Practical Fishkeeping Magazine, and has been maintaining a popular FAQ on the topic for over 10 years.
The Salt-allergy Myth
ne of the most persistent myths in fishkeeping is that catfish are allergic to salt. The rationalisation behind this is that because catfish lack scales (which is true) they are much more sensitive to the osmotic effect of brackish water (which is nonsense). Consider this: moray eels also lack scales, yet virtually all of them live in the sea, with only a handful being found in brackish or fresh water.
The ability of a fish to control the flow of salts and water in and out of its body depends not on whether it has scales or not, but on its overall physiology. This, in turn, depends on the how evolution has modified that species to fit into a particular environment. Catfish adapted to soft water habitats, for example, are indeed unlikely to to do well in a brackish water aquarium, but the same holds true for all the other soft water aquarium fish, such as barbs, tetras, loaches, gouramis, and so on. What might come as a surprise to many catfish enthusiasts is that there are lots of catfish adapted to brackish water environments, and there are two families that are primarily marine in distribution, containing relatively few species that inhabit completely freshwater environments. These are the families Ariidae and Plotosidae, known as the sea catfish and eel catfish respectively. A few other families, including the Aspredinidae, Bagridae, Clariidae, Ictaluridae, Siluridae, and Loricariidae, include species that either tolerate brackish water or are found primarily in brackish water, further shattering the myth of catfish as being allergic to salt.
Brackish water plecs
Easily the question I get asked most often is whether or not plecs can be kept in a brackish water aquarium. The short answer is probably not, but the long answer is a much more complex than that.
To begin with, there are species of loricariid catfish that are apparently adapted to slightly brackish water habitats. In aquaristic terms, that would correspond to a specific gravity, or SG, of around 1.003 to 1.005. Hypostomus ventromaculatus is one such species, being found primarily in the Amazon estuary and according to FishBase only within the tidal, brackish water region of the river. Another species, Hypostomus watwata, is also common in slightly brackish environments, even being found living among mangrove tree roots. While these fish sound like ideal additions to a low-salinity brackish aquarium alongside things like mollies, gobies, and dwarf cichlids, the problem is that they are not traded much, if at all
Hypostomus plecostomus
Hypostomus plecostomus
is another species known to inhabit slightly brackish water, though in this case such observations have often been made outside of its natural range. In Florida, for example, where this fish has become widely established, it is quite commonly found in slightly brackish water.
Of course the main problem with using this species in the brackish water aquarium is that while the name Hypostomus plecostomus is commonly used in aquarium books and magazines to refer to the standard issue, common or garden plec, it is hardly ever the species available for sale. You are far more likely to find species of Liposarcus or Pterygoblichthys masquerading as "common plecs" in most aquarium stores.
Freshwater catfish that occur in brackish water
A number of catfish families include species that tolerate brackish water even if they don't need it. Siluris glanis, for example, one of the Siluridae, is normally found in freshwater rivers but can also be the slightly brackish water fringing the Baltic and Caspian seas. The same holds true for various species of clariid and ictaluriid catfish. These fish probably don't have any specific adaptations to brackish water, it's just that they are incredibly hardy and tolerant of sub-optimal conditions. Ictalurus punctatus in particular thrives in low salinity brackish water aquaria, though its large adult size and predatory nature do limit its usefulness.
Brackish water specialists
Mystus gulio
Catfish that tolerate brackish water are one thing, but species that actually prefer brackish water conditions are something else. Mystus gulio is one such species. It is a large bagrid catfish known in its natural range (South and South East Asia) as the estuarine catfish, a good indication of its preferred habitat. It is large (45 cm), silvery, schooling catfish that has only rarely been traded as an aquarium fish. Superficially similar in form and habit to the popular Colombian shark catfish (discussed below) it contrasts with that species in requiring slightly rather than strongly brackish water. It is adaptable though, and is common in completely freshwater rivers, and is even sometimes found in the sea. Nonetheless, for optimal health, this fish should be kept in slightly brackish water around the SG 1.005 mark. While not recommended for use alongside scats or monos, which prefer more strongly brackish conditions, this would be a fine companion for large sleeper gobies, green chromides, Siamese tigers (Datnioides spp.), and other large but peaceful, low salinity, brackish water fish.
It should be noted that Mystus gulio is unique among Mystus species in being a brackish water specialist; most of the other Mystus species sold as aquarium fish are strictly freshwater animals and should be maintained accordingly.
Bunocephalus coracoideus
Another group of catfish primarily associated with freshwater habitats but including a few brackish water specialists are the banjo catfish. The small species, like the ever-popular Bunocephalus coracoideus, are entirely freshwater fish, but it is the larger ones, such as Aspredinichthys, Aspredo, and Platystacus spp., that are the brackish water specialists.
These big banjos typically grow to around 20 to 30 cm, but are otherwise very similar to the dwarf species in terms of habits and requirements. In the wild they are normally found in coastal regions, though not always in brackish water, but they are not found in the sea. Like Mystus gulio, a low salinity suits them best, although they can be maintained in freshwater aquaria too, provided the water is not too soft or acid.
Marine catfish
When it comes to salty water, two catfish families stand out: the Ariidae and the Plotosidae. The Ariidae is perhaps the best known to freshwater fishkeepers, with one species, Hexanematichthys seemanni, being very Hexanematichthys seemanni
widely sold as the Colombian shark catfish. This is a large family (around 120 species) with representatives to be found along the coastlines of all the continents except Europe and Antarctica. Australia has a number of species that have secondarily become truly freshwater fish, presumably in the absence of competition from other catfish families, but ariids are otherwise completely marine animals that only migrate into rivers when foraging for food. The Colombian shark catfish, for example, while sold as a brackish water fish, is best kept in a marine aquarium.
The Plotosidae are a smaller family (around 30 species are known) that are confined to the Indo-West Pacific. Oddly enough, most of them are strictly freshwater fish found in Australia and New Guinea, where they are known locally as "cobblers" or "tandans". Nonetheless, there's no question that the family evolved in the sea, and many of them still live there. Like the Australian freshwater ariids, the freshwater plotosids have presumably radiated to occupy the ecological niches in Australia and New Guinea that 'true' freshwater catfish occupy elsewhere.
Plotosus lineatus
Only a single species of plotosid has had had any impact on the hobby (outside of Australia, at least), Plotosus lineatus. Normally the neatly-marked juveniles are sold as a marine fish, but since the adults are 30 cm long and rather drab by comparison with most other ornamental marine fish, they haven't become at all popular. While they can be maintained in marine aquaria, they will do equally well in midto high-salinity brackish water tanks where the specific gravity is maintained at 1.010 or more.
Adults in particular seem to be very accommodating, and have even been found in completely fresh water. Plotosus lineatus is a schooling fish when young, but adults are territorial are usually end up being kept alone. They are predators, but will mix fine with fishes too large to eat, such as scats.
Just as catfish manage to span the range of ecological niches from herbivores to predators, from cold mountain streams to tropical swamps, so


Cell Design and Pull Systems 160
This class covers the basics of cellular manufacturing, including the characteristics of cells and pull systems. Includes an Interactive Lab.
Class Name:
Cell Design and Pull Systems 160
Number of Lessons:
Additional Language:
Class Outline
 - Objectives
 - Cells and Pull Systems
 - The Goals of Lean
 - Origin of Work Cells
 - Basic Cell Characteristics
 - Disadvantages of Inventory
 - Disadvantages of Push Systems
 - Advantages of Pull Systems
 - Kanban
 - Updated Kanban
 - Cell Planning
 - Cycle Time
 - Setup Reduction
 - Error Detection and Error Prevention
 - Total Productive Maintenance
 - Kaizen
 - Summary
 - Define cell.
 - Define pull system.
 - Describe the main goal of lean manufacturing.
 - Identify the combination of traditional manufacturing systems on which work cells are based.
 - Describe the characteristics of a cell.
 - Identify the disadvantages of keeping parts in inventory.
 - Identify the disadvantages of push systems.
 - Identify the advantages of pull systems.
 - Define kanban.
 - Identify modern types of kanban.
 - Describe the best method for planning work cells.
 - Define cycle time.
 - Describe the key to reducing setup time.
 - Describe how error detection applies to cellular manufacturing.
 - Describe how error prevention applies to cellular manufacturing.
 - Describe the purpose of total productive maintenance.
 - Define kaizen.
Job Roles
 - CNC Lathe Operations
 - MSSC Manufacturing Processes and Production
Vocabulary Term Definition
assembly line A linear method of manufacturing in which the object being produced passes through different work stations until it is complete.
cell A specialized grouping of people, machines, tooling, and materials. The purpose of a cell is to efficiently produce small batches of parts.
cellular manufacturing A lean manufacturing method that uses specialized groupings of machines, people, and materials.
cycle time The time that elapses from the beginning to the end of a process.
error detection The inspection of a part during and after production to determine if errors have occurred. Error detection does not try to prevent errors.
error prevention A continuous improvement method that studies why and how errors occur and looks for ways to keep them from happening again.
finishing A process such as painting or sanding that is performed after a workpiece is fully constructed.
fixturing The secure clamping of a part during various machining operations.
flow shop A manufacturing facility that produces one or two similar products using high-volume specialized equipment. An assembly line is an example of a flow shop.
in-process inspection The inspection of a part during production to detect errors. Errors that are detected early may allow the part to be reworked or prevented from continuing through the manufacturing process.
intermediate fixture A workholding device that uses subplates and standardized fixtures to minimize the need for relocating after tool changeovers.
internal customer A department or individual within the company that relies on others to satisfy the external customer. For any cell, the next cell in a process is always the internal customer.
inventory Temporary or long-term storage of parts or products that are either finished or in progress. With pull systems, inventory is eliminated.
job shop A manufacturing facility that produces several different products in smaller batches. A machine shop is a type of job shop.
kaizen A Japanese word that means "change for the better." Kaizen is a combination of maintenance, problem solving, and innovation that is generally performed by a team.
kanban A Japanese word meaning "card signal." It represents any visual method used to show the need for parts or products to be moved or produced.
linked cells A group of work cells tied together using kanban. Parts travel between cells in small batches but are fabricated one at a time within individual cells.
locating The accurate positioning of a part in relation to other known surfaces or distances.
machine shop A factory or workshop where metal is cut and shaped by machines.
milling machine A machine that uses a multi-toothed milling cutter to remove metal from the workpiece surface to create flat and angular surfaces and grooves.
pokayoke A Japanese term meaning "mistake proofing." An example of pokayoke would be a machine designed so that parts can be fixtured only in the correct position.
production kanban A kanban that contains all of the basic information about a batch, such as number and weight, plus details about what type of work should be accomplished within the cell.
project shop A manufacturing facility that produces large items, such as airplanes, by bringing the machines and materials to the project.
pull system A material management system in which parts are not delivered to machines until they are needed. Pull systems are based on actual demand for parts.
push system A production method based on keeping up with preset inventory levels or with due dates for customer orders rather than customer demand.
retooling The changing of machinery, fixtures, and tools for the production of a new part. Retooling takes place before new product runs begin.
setup reduction A lean effort that uses standardization to reduce the time it takes to perform retooling.
soldering A joining method that uses heated tin and lead to fuse parts together.
traffic The management of the movement and exchange of materials, orders, and information that takes place within a manufacturing facility.
transportation The movement of materials and parts within a manufacturing facility.
universal product code A combination of a number and a series of parallel lines, known as a bar code, that appears on consumer packaging and is used in some shops as kanban.
withdrawal kanban A kanban used to signal the movement of parts between cells. It contains just the basic information about the batch such as the number of pieces and weight.


text:
Hey guys! Im new to the forums and just started a programming course in college and im having some difficulties. The exercise is as followed:
The binary logarithm of n (log2n) is the power to which the number 2 to must be raised to obtain the value n. Write a C function that calculates log2 of an unsigned integer n using the following approach: find the most significant set bit in n and return the position of this bit. For example, if n is 17 (0b10001), the function should return 4.
The C function should have the following signature:
int mylog2(unsigned int n)
I'm not sure what to do and what "find the most significant set bit in n and return the position of this bit" means. And also how to I can do this, I certainly dont want u guys to do this for me, but some info on how to do it would be appreciated.
I have asked my teacher for help, but he just said read the goddamn books, but I have and still dont know the steps to solve this. Thanks

source: openbmb/Ultra-FineWeb


text:
Tremendous growth in data volume and complexity of data returned from planetary exploration coupled with new and emerging data science technologies are changing planetary science. From better calibrations to enhanced modelling to new methods for data management and discovery, informatics and data analytics are an increasingly important part of understanding and processing data from planetary missions. As a result, it is becoming increasingly important for the planetary science and data science communities to work together to research and develop applications of these technologies to support upcoming mission and science needs.
The PSIDA conference provides a forum to discuss approaches, challenges, and applications of informatics and data analytics technologies and capabilities in planetary science. During the three days of the conference, participants will have the opportunity to share knowledge, experience, and lessons learned in these fields and network with colleagues.
Conference topics include planetary data architectures, management, and data technologies; scalable data processing, data-driven discovery and analytics; visualization; science applications; and planetary data archiving.
The schedule is not set at this time.
- Tom Stein – Washington University, St. Louis, USA
- Dan Crichton – Jet Propulsion Laboratory, Pasadena, USA
- Alphon Altinok – Jet Propulsion Laboratory, Pasadena, USA
- Christophe Arviset – European Space Agency, Madrid, Spain
- Oleg Batanov – Russian Space Research Institute, Moscow, Russia
- Baptiste Cecconi – Paris Observatory, Paris, France
- Karin Eichentopf – German Aerospace Center, Berlin, Germany
- Ashish Mahabal – California Institute of Technology, Pasadena, USA
- Ana-Catalina Plesa – German Aerospace Center, Berlin, Germany
- Jody O'Sullivan – Washington University, St. Louis, USA
- Kiri Wagstaff – Jet Propulsion Laboratory, Pasadena, USA

source: m-a-p/FineFineWeb


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Iwas (in red cassock) and a priest (in black).
In the Syriac Orthodox Church, married priests wear a black skullcap, or phiro, while monastic priests wear the schema, eskimo. For certain sacramental functions, a priest or bishop puts on the epitrachelion (stole).
Anglican choir dress or choir habit[edit]
An Anglican priest in choir dress: cassock, surplice and tippet. The dark red of his academic hood can be seen on his shoulders.
Choir dress in Anglicanism traditionally consists of cassock, surplice and scarf (or tippet).[n 1] An academic hood may also be worn and, since 1964 in the Church of England a cope may be worn at the discretion of the minister.[2] However, the basic garment was, and is, the surplice which by the fourteenth century had become the essential choir-vestment everywhere.[3] The surplice was the only vesture permitted to the clergy in the 1552 Prayer Book, except for bishops who should use a rochet (both wore cassocks as the standard undergarment).[4] The Elizabethan Prayer Book of 1559 included the so-called Ornaments Rubric. Its legal interpretation was disputed in the nineteenth century[5] it was claimed that its inclusion in the 1662 Book of Common Prayer commanded the pre-Reformation eucharistic vestments (chasuble, dalmatic, tunicle, alb, amice, and maniple) that had been in use during the reign of Edward VI.[4] However, the Elizabethan bishops struggled to enforce the use of the surplice,[4] and the use of eucharistic vestments was discontinued until after the Oxford Movement, in the middle of the nineteenth century, when it was restored in many cathedrals and parish churches.[3] In many low-church dioceses and parishes the choir dress continued to be the norm, even at the Eucharist. The cope nevertheless continued in use for coronations and in certain cathedrals, but this may be considered an extension of "choir dress" and was sanctioned by the canons of 1603/4.[6]
The cassock is almost invariably black for priests and deacons. A traditional Anglican cassock is double-breasted, being buttoned on the shoulder rather than up the front (there may be a single button sewn to the center of the chest used to fasten the academic hood if worn). Many Anglican clergy, especially (though not exclusively) those within the catholic tradition of Anglicanism, prefer to wear the Latin single-breasted cassock. The cassock is worn with a cincture, which may take the form of a cloth sash resembling a fascia, or a simple rope girdle or leather belt. Over this is worn the surplice, which is longer and fuller than that worn by Roman Catholic clergy, sometimes reaching well below the knees. Traditionally, an academic hood is worn around the shoulders and down the back, along with a black tippet or scarf worn around the nape and hanging straight down in front. The hood and tippet were once a single garment called an almuce. (The tippet is not to be confused with the stole, which is also worn in a similar manner, but is not part of choir dress, being worn at the Eucharist and other sacramental services.) Some clergy also wear Geneva bands (or "preaching tabs") from their collars. At solemn Mattins or Evensong, the minister may wear the cope over the surplice, rather than tippet and hood. During some periods of history a black gown, either academic or 'Genevan', was worn for Morning and Evening Prayer instead of the surplice, which was reserved for use at the Holy Communion - the cassock, bands, gown, academic hood, and tippet still being the normal liturgical costume for ordained minister of the Church of Scotland and other Reformed and Presbyterian churches.
Chaplains in the Armed Forces wear tippets with officially sanctioned badges and any medals they have achieved. A bishop or priest may wear a tippet with the arms of the seminary from which he received his degree. In England some cathedral clergy wear tippets on which is embroidered the distinctive symbol or cathedral coat of arms. Members of the high church or Anglo-Catholic parts of the church sometimes wear choir dress of a more Roman Catholic style, including a shorter surplice (or cotta), a stole (and sometimes a biretta), excluding hood and tippet.
Readers when officiating often wear a blue tippet, or, in the United States, a black tippet displaying the arms of the diocese.
Anglican bishops usually wear a purple cassock. Over this, instead of the surplice, they wear the rochet with red or black chimere and matching cuffs, black tippet, and sometimes an academic hood.
Anglican Bishop - choir dress.svg
Anglican Canon - choir dress.svg
Anglican Priest - choir dress.svg
Anglican Reader - choir dress.svg
Bishop Canon (cassock colors vary) Priest/Deacon Reader
Notes & References[edit]
 1. ^ Tippett is often used as a synonym of "scarf", but historically it may also have been used in the sixteenth and seventeenth centuries for a type of non-academic hood which extended forward down over the chest. (Cross, F.L.; Livingstone, E.A., eds. (1974). "Tippet"". The Oxford Dictionary of the Christian Church (2 ed.). Oxford: Oxford University Press.)
 1. ^ a b Grisebrooke, W. Jardine. Vestments in Jones, Cheslyn, Wainright, Geoffrey & Yarnold, Edward. The Study of Liturgy SPCK: 1979, p.489
 2. ^ Canons of 1964 and following years: B.8.3
 3. ^ a b Simpson, John A. arts Surplice & Vestments in The New International Dictionary of the Christian Church J.D. Douglas(ed.) Exeter:Paternoster (1974)
 4. ^ a b c Procter & Frere. A New History of the Book of Common Prayer, MacMillan & Cº (1902), pp.82; 362ff & 110 respectively
 5. ^ Cross, F.L.; Livingstone, E.A., eds. (1974). "Ornaments Rubric, The". The Oxford Dictionary of the Christian Church (2 ed.). Oxford: Oxford University Press.
 6. ^ Canon 24
External links[edit]


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OpenVMS Cluster Systems
Previous Contents Index
F.2.3 Excessive Packet Losses on LAN Paths
Prior to OpenVMS Version 7.3, an SCS virtual circuit closure was the first indication that a LAN path had become unusable. In OpenVMS Version 7.3, whenever the last usable LAN path is losing packets at an excessive rate, PEDRIVER displays the following console message:
%PEA0, Excessive packet losses on LAN path from local-device-name
 to device-name on REMOTE NODE node-name
This message is displayed when PEDRIVER recently had to perform an excessively high rate of packet retransmissions on the LAN path consisting of the local device, the intervening network, and the device on the remote node. The message indicates that the LAN path has degraded and is approaching, or has reached, the point where reliable communications with the remote node are no longer possible. It is likely that the virtual circuit to the remote node will close if the losses continue. Furthermore, continued operation with high LAN packet losses can result in significant loss in performance because of the communication delays resulting from the packet loss detection timeouts and packet retransmission.
The corrective steps to take are:
 1. Check the local and remote LAN device error counts to see whether a problem exists on the devices. Issue the following commands on each node:
 $ SHOW DEVICE local-device-name
 $ MC SCACP
 SCACP> SHOW LAN device-name
 $ MC LANCP
 LANCP> SHOW DEVICE device-name/COUNT

 2. If device error counts on the local devices are within normal bounds, contact your network administrators to request that they diagnose the LAN path between the devices.
F.2.4 Preliminary Network Diagnosis
If the symptoms and preliminary diagnosis indicate that you might have a network problem, troubleshooting LAN communication failures should start with the step-by-step procedures described in Appendix C. Appendix C helps you diagnose and solve common Ethernet and FDDI LAN communication failures during the following stages of OpenVMS Cluster activity:
 - When a computer or a satellite fails to boot
 - When a computer fails to join the OpenVMS Cluster
 - During run time when startup procedures fail to complete
 - When a OpenVMS Cluster hangs
The procedures in Appendix C require that you verify a number of parameters during the diagnostic process. Because system parameter settings play a key role in effective OpenVMS Cluster communications, Section F.2.6 describes several system parameters that are especially important to the timing of LAN bridges, disk failover, and channel availability.
F.2.5 Tracing Intermittent Errors
Because PEDRIVER communication is based on channels, LAN network problems typically fall into these areas:
 - Channel formation and maintenance
 Channels are formed when HELLO datagram messages are received from a remote system. A failure can occur when the HELLO datagram messages are not received or when the channel control message contains the wrong data.
 - Retransmission
 A well-configured OpenVMS Cluster system should not perform excessive retransmissions between nodes. Retransmissions between any nodes that occur more frequently than once every few seconds deserve network investigation.
Diagnosing failures at this level becomes more complex because the errors are usually intermittent. Moreover, even though PEDRIVER is aware when a channel is unavailable and performs error recovery based on this information, it does not provide notification when a channel failure occurs; PEDRIVER provides notification only for virtual circuit failures.
However, the Local Area OpenVMS Cluster Network Failure Analysis Program (LAVC$FAILURE_ANALYSIS), available in SYS$EXAMPLES, can help you use PEDRIVER information about channel status. The LAVC$FAILURE_ANALYSIS program (documented in Appendix D) analyzes long-term channel outages, such as hard failures in LAN network components that occur during run time.
This program uses tables in which you describe your LAN hardware configuration. During a channel failure, PEDRIVER uses the hardware configuration represented in the table to isolate which component might be causing the failure. PEDRIVER reports the suspected component through an OPCOM display. You can then isolate the LAN component for repair or replacement.
Reference: Section F.7 addresses the kinds of problems you might find in the NISCA protocol and provides methods for diagnosing and solving them.
F.2.6 Checking System Parameters
Table F-3 describes several system parameters relevant to the recovery and failover time limits for LANs in an OpenVMS Cluster.
Table F-3 System Parameters for Timing
Parameter Use
RECNXINTERVAL
Defines the amount of time to wait before removing a node from the OpenVMS Cluster after detection of a virtual circuit failure, which could result from a LAN bridge failure. If your network uses multiple paths and you want the OpenVMS Cluster to survive failover between LAN bridges, make sure the value of RECNXINTERVAL is greater than the time it takes to fail over those paths.
Reference: The formula for calculating this parameter is discussed in Section 3.4.7.
MVTIMEOUT
Defines the amount of time the OpenVMS operating system tries to recover a path to a disk before returning failure messages to the application. Relevant when an OpenVMS Cluster configuration is set up to serve disks over either the Ethernet or FDDI. MVTIMEOUT is similar to RECNXINTERVAL except that RECNXINTERVAL is CPU to CPU, and MVTIMEOUT is CPU to disk.
SHADOW_MBR_TIMEOUT
Defines the amount of time that the Volume Shadowing for OpenVMS tries to recover from a transient disk error on a single member of a multiple-member shadow set. SHADOW_MBR_TIMEOUT differs from MVTIMEOUT because it removes a failing shadow set member quickly. The remaining shadow set members can recover more rapidly once the failing member is removed.
Note: The TIMVCFAIL system parameter, which optimizes the amount of time needed to detect a communication failure, is not recommended for use with LAN communications. This parameter is intended for CI and DSSI connections. PEDRIVER (which is for Ethernet and FDDI) usually surpasses the detection provided by TIMVCFAIL with the listen timeout of 8 to 9 seconds.
F.2.7 Channel Timeouts
Channel timeouts are detected by PEDRIVER as described in Table F-4.
Table F-4 Channel Timeout Detection
PEDRIVER Actions Comments
Listens for HELLO datagram messages, which are sent over channels at least once every 3 seconds Every node in the OpenVMS Cluster multicasts HELLO datagram messages on each LAN adapter to notify other nodes that it is still functioning. Receiving nodes know that the network connection is still good.
Closes a channel when HELLO datagrams or sequenced messages have not been received for a period of 8 to 9 seconds Because HELLO datagram messages are transmitted at least once every 3 seconds, PEDRIVER times out a channel only if at least two HELLO datagram messages are lost and there is no sequenced message traffic.
Closes a virtual circuit when:
 - No channels are available.
 - The packet size of the only available channels is insufficient.
The virtual circuit is not closed if any other channels to the node are available except when the packet sizes of available channels are smaller than the channel being used for the virtual circuit. For example, if a channel fails over from FDDI to Ethernet, PEDRIVER may close the virtual circuit and then reopen it after negotiating the smaller packet size that is necessary for Ethernet segmentation.
Does not report errors when a channel is closed OPCOM "Connection loss" errors or SYSAP messages are not sent to users or other system applications until after the virtual circuit shuts down. This fact is significant, especially if there are multiple paths to a node and a LAN hardware failure occurs. In this case, you might not receive an error message; PEDRIVER continues to use the virtual circuit over another available channel.
Reestablishes a virtual circuit when a channel becomes available again PEDRIVER reopens a channel when HELLO datagram messages are received again.
F.3 Using SDA to Monitor LAN Communications
This section describes how to use SDA to monitor LAN communications.
F.3.1 Isolating Problem Areas
If your system shows symptoms of intermittent failures during run time, you need to determine whether there is a network problem or whether the symptoms are caused by some other activity in the system.
Generally, you can diagnose problems in the NISCA protocol or the network using the OpenVMS System Dump Analyzer utility (SDA). SDA is an effective tool for isolating problems on specific nodes running in the OpenVMS Cluster system.
Reference: The following sections describe the use of some SDA commands and qualifiers. You should also refer to the OpenVMS Alpha System Analysis Tools Manual or the OpenVMS VAX System Dump Analyzer Utility Manual for complete information about SDA for your system.
F.3.2 SDA Command SHOW PORT
The SDA command SHOW PORT provides relevant information that is useful in troubleshooting PEDRIVER and LAN adapters in particular. Begin by entering the SHOW PORT command, which causes SDA to define cluster symbols. Example F-1 illustrates how the SHOW PORT command provides a summary of OpenVMS Cluster data structures.
Example F-1 SDA Command SHOW PORT Display
$ ANALYZE/SYSTEM
SDA> SHOW PORT
VAXcluster data structures
--------------------------
 --- PDT Summary Page ---
 PDT Address Type Device Driver Name


text:
Available under a Creative Commons Attribution Non-Commercial Share Alike 4.0 International Licence
Health policy and services, Business and Management.
Non-linear processes within complex systems are difficult to predict. Using discrete event simulation (DES) models can be helpful for presenting the uncertainty level embedded within these processes. However, the interpretations of the resulting outcomes can be challenging to analyze. This is evident when experimenting with simulation models, and therefore requires the adaptation of existing models. Introducing cyclic entities such as interconnected resources to the simulation model adds a new level of complexity to the model. In practical cases, decision makers often demand a model that enables them to make quick decisions with less complexity involved. However, these individuals still want to be assured of a high degree of accuracy in the results. This article demonstrates how an analytical representation of complex DES models can be developed in order to facilitate prompt yet effective solutions for decision makers. This analytical representation provides a brief overview of the simulation results by using the staff scheduling and nurses' utilization approaches. Results of the effective use of DES model and managers feedback are encouraging.
Thorwarth, M., Rashwan, W., & Arisha, A. (2015), An analytical representation of flexible resource allocation in hospitals, Flexible Services and Manufacturing Journal, Vol. 26, Issues 93, pp 1989 – 2014, Springer US, DOI: 10.1007/s10696-_PHONE_-4.


Monitor System Activity Using Extended Events
Applies to: SQL Server Azure SQL Database
This procedure illustrates how Extended Events can be used with Event Tracing for Windows (ETW) to monitor system activity. The procedure also shows how the CREATE EVENT SESSION, ALTER EVENT SESSION, and DROP EVENT SESSION statements are used.
Accomplishing these tasks involves using Query Editor in SQL Server Management Studio to carry out the following procedure. The procedure also requires using the command prompt to run ETW commands.
To monitor system activity using Extended Events
 1. In Query Editor, issue the following statements to create an event session and add two events. These events, checkpoint_begin and checkpoint_end, fire at the beginning and end of a database checkpoint.
 CREATE EVENT SESSION test0
 ON SERVER
 ADD EVENT sqlserver.checkpoint_begin,
 ADD EVENT sqlserver.checkpoint_end
 WITH (MAX_DISPATCH_LATENCY = 1 SECONDS)
 go

 2. Add the bucketing target with 32 buckets to count the number of checkpoints based on the database ID.
 ALTER EVENT SESSION test0
 ON SERVER
 ADD TARGET package0.histogram
 (
 SET slots = 32, filtering_event_name = 'sqlserver.checkpoint_end', source_type = 0, source = 'database_id'
 )
 go

 3. Issue the following statements to add the ETW target. This will enable you to see the begin and end events, which is used to determine how long the checkpoint takes.
 ALTER EVENT SESSION test0
 ON SERVER
 ADD TARGET package0.etw_classic_sync_target
 go

 4. Issue the following statements to start the session and begin event collection.
 ALTER EVENT SESSION test0
 ON SERVER
 STATE = start
 go

 5. Issue the following statements to cause three events to fire.
 USE tempdb
 checkpoint
 go
 USE master
 checkpoint
 checkpoint
 go

 6. Issue the following statements to view the event counts.
 SELECT CAST(xest.target_data AS xml) Bucketizer_Target_Data_in_XML
 FROM sys.dm_xe_session_targets xest
 JOIN sys.dm_xe_sessions xes ON xes.address = xest.event_session_address
 JOIN sys.server_event_sessions ses ON xes.name = ses.name
 WHERE xest.target_name = 'histogram' AND xes.name = 'test0'
 go

 7. At the command prompt, issue the following commands to view the ETW data.
 Note
 To get help for the tracerpt command, at the command prompt, enter tracerpt /?.
 logman query -ets --- List the ETW sessions. This is optional.
 logman update XE_DEFAULT_ETW_SESSION -fd -ets --- Flush the ETW log.
 tracerpt %temp%\xeetw.etl -o xeetw.txt --- Dump the events so they can be seen.

 8. Issue the following statements to stop the event session and remove it from the server.
 ALTER EVENT SESSION test0
 ON SERVER
 STATE = STOP
 go

 DROP EVENT SESSION test0
 ON SERVER
 go

See Also
CREATE EVENT SESSION (Transact-SQL)
ALTER EVENT SESSION (Transact-SQL)
DROP EVENT SESSION (Transact-SQL)
Extended Events Catalog Views (Transact-SQL)
Extended Events Dynamic Management Views
SQL Server Extended Events Targets


text:
Depicting snow in woodcuts
White inks were not usually employed in printing Japanese woodcuts, so snow was commonly depicted by leaving areas of the paper blank. Snowflakes were usually created by carving nicks out of the surface of the colour blocks, so that flecks of paper appear like flakes of snow.
Here nicks have been carved out of the blocks used to print the man's hair so that it appears as though snowflakes are falling in front of him.
Exceptionally, in special luxury editions or private commissions, white pigment was flicked onto the surface of the paper to create extra snowflakes after the colours had been printed.
The white pigment is whiter than the colour of the paper, so the snowflakes stand out against the snow. This pigment was traditionally made from seashells and known as gofun (calcium carbonate), but lead based whites were also used, as in this example.
The flicked pigment cannot be precisely controlled, so the effect is random in each impression, but in this example the pigment was brushed through holes in a stencil, rather than being flicked, so the snowflakes appear in exactly the same place in each example of the print (some of the snowflakes have darkened over time).
Another way of depicting snow was to emboss the surface of the thick paper using a carved block without any ink. Here this technique has been used to create ridges in the snow behind the women. The ridges are modelled purely by the light falling on the surface of the print.

source: HuggingFaceFW/fineweb-edu


text:
These instructions apply to you if the IT Admin at your school has created teams for you based on your school roster. They also apply to you whether you're using a desktop or mobile device.
Questions about setting up Early Access for the first time? Ask your IT Admin for help and refer them to this set of steps.
Your IT Admin creates your new class teams at the beginning of each term and takes care of adding the student roster. However, you have access to the class team before your students can view it and begin participating. This means you have time to set up, add files, and get organized before granting access to your students. Once you're ready for students to access a team, follow these steps to activate it:
You'll notice a banner at the top of all your new class teams that shows you how many students are waiting to join the class.
Navigate to a team and select Activate.
Select Activate again to confirm that you'd like your students to access the team.
View students waiting to join
To review the list of students who have been added to your class but don't have access to it yet, navigate to a class team and select More options >Manage team.
You'll see a list of students waiting to join underneath the Members tab.


text:
Films and Video
Viewing and discussion programs that present documentary or independent films related to the Building Common Ground themes, followed by a facilitated discussion can bring audiences together to explore meaningful issues and understand and relate to each other.
The following video galleries contain an array of viewing materials that range from video shorts to full-length documentary films. Libraries are encourage to incorporate video content into their program plans to create multi-media elements to Building Common Ground series.
Libraries may use the provocative video shorts provided as added texture to book discussions or context setting for facilitated discussions; the weighty feature length Forgiveness documentaries as a centerpiece for additional multi-format programming, and other video content, such as Krista Tippet's TED talk as springboards to larger discussions of community issues. Libraries are encouraged to explore the wealth of film and video content recommended in the Video Galleries to create their multiformat Building Common Ground program series.


text:
From: The Honorable Colleen Hanabusa
Reps. Hanabusa and Gabbard would like to invite your boss to sign the appropriations request letter (below) requesting critical funding for the Volcano Hazards Program. This request is to the Appropriations Subcommittee on the Interior, Environment,
and Related Agencies, which is due TODAY.
Here is a list of states this program benefits: Alaska, Arizona, California, Colorado, Hawaii, Idaho, Nevada, Northern Marianas Islands, Oregon, Utah, Washington, Wyoming.
And, here is a map of the areas where the volcanic activity monitored by this program are:
Current signatures: Hanabusa, Gabbard, Don Young, DeFazio
Deadline to sign on: 4pm TODAY. Please email _EMAIL_ to sign on.
Dear Chairman Calvert and Ranking Member McCollum,
As the House Appropriations Subcommittee on Interior, Environment, and Related Agencies considers appropriations for Fiscal Year 2018, we respectfully request this subcommittee to provide $26,238,000 for the Volcano Hazards Program, which is overseen by
the U.S. Geological Survey.
The Volcano Hazards Program is critical in understanding the potential impacts of the United States' 169 potentially active volcanoes in the United States' western states, Alaska, Hawaii, and the U.S. Pacific territories. Under the mandate of the Robert
T. Stafford Disaster Relief and Emergency Assistance Act, this program minimizes the potential of devastating social and economic impacts on nearby communities and ecosystems through delivery of effective forecasts, warnings, and information regarding volcanic
hazards based on scientific data and on understanding of volcanic processes.
The scientific information collected through the Volcano Hazards Program is essential in order to effectively communicate findings and activity alerts to emergency-management professionals and the public. In addition, the information collected helps communities
develop comprehensive hazard zonation maps and assessments, long-term eruption forecasting, land-use planning, and short-term emergency planning.
Ensuring programmatic resources for the Volcano Hazards Program will ensure and improve health and safety protections of residents, businesses, and tourists in areas where there is volcanic activity. We thank this subcommittee for its attention and consideration
of this request.


text:
A concise and divergent approach to radicamine B and hyacinthacine A(3) based on a step-economic transformation
- 化学化工－已发表论文
Based on our recently developed step-economic methodology of reductive alkylation of lactams/amides, we have developed a two-step synthesis of azasugar radicamine B (2a) and a four-step synthesis of azasugar hyacinthacine A(3) (5) from the common chiral building block 12. Hantzsch ester (HEH) was used as a milder hydride donor in the one-pot stereoselective reductive alkylation of lactam 12. The Wacker oxidation of fully substituted pyrrolidine derivative 2,5-trans-17 led to the synthesis of hyacinthacine A(3) (5). Compound 2,5-trans-17 could also serve as a plausible key intermediate for the synthesis of broussonetine sub-class of azasugars. (C) 2012 Elsevier Ltd. All rights reserved.


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Non-Abelian Stokes Theorems in Yang–Mills and Gravity Theories 1 Introduction PDF
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Preview Non-Abelian Stokes Theorems in Yang–Mills and Gravity Theories 1 Introduction
NORDITA-2000/65 HE Non-Abelian Stokes Theorems in Yang–Mills and Gravity Theories (cid:5)(cid:3) (cid:3) Dmitri Diakonov and Victor Petrov (cid:5) NORDITA, Blegdamsvej 17, DK-2100 Copenhagen Ø, Denmark (cid:3) St.Petersburg Nuclear Physics Institute, Gatchina 188 350, Russia E-mail: [email protected], [email protected] Abstract We recall the non-Abelian Stokes theorem for the Wilson loop in the Yang –Mills theory and discuss its meaning. Then we move to 'gravitational Wilson loops', i.e. to holonomies in curved d = 2,3,4 spaces and derive 'non-Abelian Stokes theorems' for these quantities as well, which are similar to our formula in the Yang–Mills theory. In particular we derive an elegant formula for the holonomy in the case of a constant- curvature background in three dimensions and a formula for small-area loops in any number of dimensions. 1 Introduction One of the main objects in the Yang{Mills theory as well as in gravity is the parallel trans- porter along closed contours, or holonomy. In Yang{Mills theory it is conventionally called the Wilson loop; it can be written as a path-ordered exponent, (cid:73) 1 dx(cid:22) a a W = Tr P exp i d(cid:28) A T ; (1) r (cid:22) d(r) d(cid:28) where x(cid:22)((cid:28)) with 0 (cid:20) (cid:28) (cid:20) 1 parametrizes the closed contour, Aa is the Yang{Mills (cid:12)eld (or (cid:22) connection) and Ta are the generators of the gauge group in a given representation r whose dimension is d(r). In curved Riemannian spaces the 'gravitational Wilson loop' or holonomy for d-dimensional vectors can be also written as a trace of the path-ordered exponent of the connection, this time of the Christo(cid:11)el symbol, (cid:34) (cid:35) 1 (cid:73) dx(cid:22) (cid:20) WG = P exp − d(cid:28) Γ : (2) vector (cid:22) d d(cid:28) (cid:20) One can also consider parallel transporters of spinors in curved background: in this case the holonomy is de(cid:12)ned not by the Christo(cid:11)el symbols but by the spin connection which is not uniquely determined by the metric tensor, see the precise de(cid:12)nitions below. The Yang{Mills Wilson loop is invariant under gauge transformations of the background (cid:12)eld A ; the gravitational Wilson loop is invariant under general coordinate transformations (cid:22) or di(cid:11)eomorphisms, provided one transforms the contour as well. Itisgenerallybelieved thatinthreeandfourdimensions theaverage oftheWilsonloopin a pure Yang{Mills quantum theory exhibits an area behaviour for large and simple contours (like ﬂatrectangular). This shouldbetruenotforallrepresentations but thosewith'N-ality' nonequal zero; in the simplest case of the SU(2) gauge group these are representations with half-integer spin J. One of the di(cid:14)culties in proving the asymptotic area law for the Wilson loop in half- integer representations (and proving that in integer representations it is absent) is that the Wilson loop is a complicated object by itself: it is impossible to calculate it analytically in a general non-Abelian background (cid:12)eld. Meanwhile, it is sometimes easier to average a quantity over an ensemble than to calculate it for a speci(cid:12)c representative. However, in case of the Wilson loop the path-ordering is a serious obstacle on that way. A decade ago we have suggested a formula for the Wilson loop in a given background belonging to any gauge group and any representation [1]. In this formula the path order- ing along the loop is removed, but at the price of an additional integration over all gauge transformations of the given non-Abelian background (cid:12)eld, or, more precisely, over a coset depending on the particular representation in which the Wilson loop is considered. Fur- thermore, the Wilson loop can be presented in a form of a surface integral [2], see the next section. We call this representation the non-Abelian Stokes theorem. It is quite di(cid:11)erent from previous interesting statements [3, 4, 5, 6] also called by their authors 'non-Abelian Stokes theorem' but which involve surface ordering. Our formula has no surface ordering. A classi(cid:12)cation of 'non-Abelian Stokes theorems' for arbitrary groups and their representations has been given recently by Kondo et al. [7] who used the naturally arising techniques of ﬂag manifolds. Though these formulae usually do not facilitate (cid:12)nding Wilson loops in particular back- grounds, they can be used to average Wilson loops over ensembles of Yang{Mills con(cid:12)gura- tions or over di(cid:11)erent metrics, and in more general settings, see. e.g. [8, 9, 7, 10]. The main aim of this paper is to present new formulae for the gravitational holonomies in curved d = 2;3;4 spaces: they are similar to our non-Abelian Stokes theorem for the Yang{Mills case. We get rid of the path ordering in eq. (2) and write down the holonomies as exponents of surface integrals. Instead of path ordering we have to integrate over certain covariantly unit vectors (in case of d = 3) or covariantly unit (anti)self-dual tensors (in case of d = 4). Remarkably, these formulae put parallel transporters of di(cid:11)erent spins on the same footing. In particular, holonomies for half-integer spins are presented in terms of the metric tensor (and its derivatives) only but not in terms of the vielbein or spin connection. 2 Apart from purely theoretical interest we have a practical motivation in mind. Quite recently we have shown, both in the continuum and on the lattice, that the SU(2) Yang{ Mills partition function in d = 3 can be exactly rewritten in terms of local gauge-invariant quantitiesbeingthesixcomponentsofthemetrictensorofthedualspace[11]. Thisrewriting may beuseful to investigate the spectrum and the correlation functions of the theory directly in a gauge-invariant way, but it is insu(cid:14)cient to study the interactions of external sources since they couple to the Yang{Mills potential and not to gauge-invariant quantities. The present paper demonstrates, however, that a typical source, i.e. the Yang-Mills Wilson loop can be expressed not only through the potential (or connection) but also through the metric tensor which is gauge-invariant. Thus, not only the partition function but also Wilson loops in the d = 3 Yang{Mills theory can be expressed through local gauge-invariant quantities. We leave a detailed formulation of the resulting theory for a forthcoming publication. Thoughthemaincontentofthepaperarethenon-AbelianStokestheoremsforholonomies in 3 and 4 dimensions, we have added three short sections with relevant material. We add for completeness the Stokes theorem in two dimensions, compute the holonomy in a special case of constant curvature with cylinder topology in three dimensions and give a general formula for the 'gravitational Wilson loop' for small loops in any number of dimensions. 2 Non-Abelian Stokes theorem in Yang–Mills theory Let (cid:28) parametrize the loop de(cid:12)ned by the trajectory x(cid:22)((cid:28)) and A((cid:28)) be the tangent compo- nent of the Yang{Mills (cid:12)eld along the loop in the fundamental representation of the gauge group, A((cid:28)) = Aatadx(cid:22)=d(cid:28), Tr(tatb) = 1(cid:14)ab. The gauge transformation of A((cid:28)) is (cid:22) 2 d A((cid:28)) ! S((cid:28))A((cid:28))S−1((cid:28))+iS((cid:28)) S−1((cid:28)):


Pongal is one of the most popular and loved festivals of South India!
It is a harvest festival, Makar Sankranti/ Pongal marks the end of the winter solstice, which symbolizes the end of the long winter nights and the celebration at the coming of the long sunny days. It also signifies the happiness of the farmers at getting new crops. It is called the Harvest festival of southern India!
Families come together to welcome the harvest season and is specially marked by its distinct traditional rituals. Some of the most common rituals that are Cleaning the clutter of our home, Flying Kites, Cooking sweet/sakarai pongal in an open fire!
So how can we involve our Toddler in the celebration of pongal? How do we get them to be excited about the festival and better understand its Traditional Importance?!
3 creative Pongal art and craft activities you can do with your toddler
Activity 1: Drawing the pongal pot!!
Encourage children to draw the pongal pot, but with a twist! Make them use natural and locally available materials around the house and garden to decorate their Drawing!
Example Use Sand to colour the pongal pot.
Use cotton to show the pongal.
Use dried and fallen leafs to show sugarcane.
Activity 2: Making kites:
Kites are flown all across India to celebrate the new harvest of the farmers! It is easy to make miniature kites with Materials available around the house. It makes for a grate piece of art to display too!
Find dried fallen leaves in the shape of kites/Make mini diamond shaped kites with paper. Puncture the mini kites with small holes. Insert the strings through the holes and fasten the kites onto to a large twig.
Activity 3: Sculpting The pongal pot!
Here is another creative way to make mini pongal pot art using natural materials!
Using play dough or Chappathi dough make the shape of the pongal pot, sugar cane, fruits, coconut and use dried leaves as a plate for the fruits and coconut!


text:
Temperatures in the Pyrenees mountain range have been climbing particularly rapidly in recent decades — with maximum temperatures there rising by more than half a degree Celsius by decade from 1970 to 2013 — according to a new study from the Rovira i Virgili University's Centre for Climate Change.
Overall, temperatures there rose by around an average of 0.11° Celsius per decade over the last century (1920—2013). As something of a comparison here, the temperature rise in Spain over the last 30 or so years has been 2.5° Celsius, and the average temperature rise in Europe as a whole over the same time period has been 0.95° Celsius.
The lead author of the new study, Núria Pérez-Zanón, commented on the temperature rise in the Pyrenees: "However this change is particularly marked in the most recent period (1970 to 2013), when maximum temperature rose by over half a degree per decade (0.57 °C per decade)."
A press release provides more: "In order to analyse this climate change in the Pyrenees, a team from Rovira i Virgili University's Centre for Climate Change collected hundreds of climate series from meteorological observatories on the southern side of the Central Pyrenees and analysed the most complete and representative series from the area for the period 1910–2013.
"According to the paper, climate change had a greater impact during the latest period, particularly in the spring and summer months. Between 1950 and 2013, the percentage of hot years doubled, while the percentage of cold years decreased by half. There has been an upward trend in this parameter, with 18 of the last 20 years being hot years."
Notably, the rise in minimum temperature in the Pyrenees was less extreme than the rise in maximum temperature — at around 0.23° Celsius per decade over the 1970–2013 time period. As far as seasonal variation goes, spring has been the season that has warmed the most — with regard to both maximum and minimum temperatures. Accompanying this, there has been a drop in annual precipitation, though it is as of yet considered to be "not significant."
"Individual series were subject to strict daily and monthly quality control to detect anomalous values, as well as homogeneity adjustments to minimise bias introduced by non-climate-related changes, such as location, modifications to the surroundings, or the equipment itself," continued Pérez-Zanón.
As a reminder here, the Iberian peninsula as a whole is facing a harsh future as regards climate change — with rising temperatures and increasing aridity expected to put an extreme damper on regional agricultural productivity within just the near future.
The new findings are detailed in a paper published in the International Journal of Climatology.
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_i A_i, and if I is a random variable such that \mathbb{P}(I=i) = x_i one has \mathbb{E} A_I = A x. Using this randomization in a Stochastic MD-SP one obtains the exact same rate of convergence (in expectation) but now each step has time complexity of order O(n), resulting in an overall complexity to reach an \epsilon-optimal point (in expectation) of O(\|A\|_{\max}^2 \frac{n \log n}{\epsilon^2}). This result is especially amazing since we obtain a sublinear time algorithm (the complexity is \tilde{O}(n) while the 'size' of the problem is O(n^2)). One can propose an even better algorithm based on Mirror Prox with a complexity of \tilde{O}(n / \epsilon) and we refer the reader to this book chapter by Juditsky and Nemirovski for more details.
This entry was posted in Optimization. Bookmark the permalink.
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text:
When surveyed on perception of care, parents' responses differed based on racial, ethnic, and socioeconomic factors.
Perceptions of care are influenced by disrespect from staff and clinicians because of racial, ethnic, and socioeconomic factors, according to a recent study.
Experience of care is directly associated with quality of health care, as positive patient experience has been linked to improved safety and clinical outcomes, improved adherence to treatment plans, and less use of health care. Provider communication experience has a significant impact on outcomes.
Race, ethnicity, primary language, and insurance status have direct impacts on patient experience in both adult and pediatric populations. Patients have reported feeling misunderstood, not receiving proper communication or time devoted from clinicians, or lack of culturally effective care from clinicians.
To understand how families of different racial, ethnic, and socioeconomic backgrounds experience pediatric outpatient care, investigators conducted a study consisting of semi-structured interviews.
Participants included parents or guardians of pediatric patients who had received care at primary care, medical subspecialty, or surgical subspecialty clinics in the past 3 months. There were 80 interviews lasting 40 to 60 minutes during the study period, with participants from a variety of racial and ethnic groups, insurance statuses, and languages.
The participant sample included 19 Asian parents, 18 Black, 13 Hispanic and English speaking, 12 Hispanic and Spanish speaking, and 18 White, properly balanced through the 3 clinics and among insurance status. Along with visiting a clinic in the past 3 months, children were also expected to have visited a clinic at least once in the prior year to be eligible.
Inductive and deductive analysis was used to evaluate interview data and expand on themes from prior research. Clinicians, a qualitative researcher, and research assistants participated in data analysis.
Interview data indicated an overarching theme of "discrimination and disrespect," seen in every stage of care. Three primary themes were also observed. The first was mitigation of system issues, where overall perception of care was impacted by parents' experience with clinicians or staff working to mitigate system issues.
The second theme was the role of personal interactions, where negative experiences were mitigated by positive relationships between families and clinicians. The third theme was effective explanations, where patient confidence in care was significantly affected by clear and detailed explanations by clinicians.
Negative experiences in these 3 themes were more common in those with public insurance, except for effective explanations. Asian parents with public insurance reported the greatest proportion of negative sentiments.
Assumptions on family culture, financial status, or background most often led to disrespect or discrimination. Black parents and Hispanic parents experienced the greatest proportion of negative comments, followed by Asian parents.
Negative assumptions often resulted in parents feeling targeted by clinicians or staff based on culture or background. One instance in the study saw a parent offered informational materials in Vietnamese feeling that assumptions were being made about her family's proficiency in speaking English. Similar experiences were seen based on socioeconomic status.
These results show how racial, ethnic, and socioeconomic factors can affect perception of care. Insurance status was a notable factor in how perceptions of care differed between participants. Overall, the study shows the importance of interactions between family and clinicians in creating a positive experience.
Luff D, Buscher SW, Ward VL, Ballal SA, Holden P, Pierre R, et al. Understanding racial, ethnic, and socioeconomic differences in the ambulatory care experience. Pediatrics. 2022;150(6). doi:10.1542/peds.2021-056001


text:
Most commonly encountered backgrounds in re-skimming jobs will need no pre-treatment before using our Thistle UniFinish. However there are a few that will need some preparation first and a very small number where Thistle UniFinish is not suitable even with pre-treatment.
Backgrounds requiring no pre-treatment:
All backgrounds need checking to see that they are clean, sound and free from dust. After checking this, no pre-treatment is needed for:
- Most paints, including matt, silk, vinyl, eggshell emulsions, kitchen/bathroom paint
- Walls stripped of wallpaper (with minimal wallpaper adhesive remaining)
- Painted texture compounds
- Undercoat plaster, except if very high suction (see below)
- Skim finish plaster
- Tile adhesive
Some preparation or pre-treatment is needed for:
- Very dirty backgrounds
- Loose or friable surfaces – these need to be stripped back to a sound surface. Loose layers can be identified by a hollow sound when tapped, and friable surfaces are problematic if it is possible to keep rubbing dust off them by hand. After stripping them back, the sound surface can then be assessed – in many cases the required plaster thickness will necessitate dubbing out, patching or complete re-plastering with a new undercoat before refinishing.
- Extremely high suction backgrounds – e.g. some lime-based or sand/cement backgrounds – these need suction control, which can be done with one application of Thistle GypPrime (diluted as required – it is intended to soak in and block pores within the background, not to remain at the surface). PVA may also be suitable. If this suction control is not done and the first application of Thistle UniFinish crazes severely, the suction should be controlled before continuing. For tips on dealing with more mild suction however see below.
Unsuitable backgrounds include:
- Unpainted texture compounds – these can soften significantly when wetted, leading to adhesion failure within the compound or of the whole compound layer from the original substrate
- Self-cleaning or anti-graffiti paints – these are often designed to not fully harden, or to have a deliberately water-repellent or weak surface layer so that materials that stick to them are removed easily, so they are not suitable for plastering
- Surfaces where there is flaking or delamination between layers, and poorly bonded, friable or dusty surfaces – clearly there is a high risk of failure unless such materials are removed
- Unpainted Artex and other texture compounds
What about backgrounds not listed here?
Our recommendations and advice come from controlled testing and "real-world" trials across many sites and situations. In re-skimming work, other backgrounds will inevitably occur but we have not experienced them often enough to have sufficient data to support a clear recommendation. All we can suggest is that customers apply common sense and caution – e.g. it may be appropriate to test a small area in some cases, and to remember that it is not enough that Thistle UniFinish adheres to the surface itself – the whole system of previous layers needs to be stable and to hold together during and after refinishing. If there is doubt about whether it will, then removal or overboarding with a system like GypLyner UNIVERSAL should be considered.
What about painted Artex and other texture compounds?
If painted they are probably suitable, but note the following:
- They still need to be checked for cleanliness and soundness
- Deep texture patterns will be more difficult to cover than shallow patterns
- Scraping the peaks off a deep texture before plastering is not recommended for two reasons: 1) if the compound is old enough it may contain asbestos and 2) scraping removes all paint from small areas, exposing unpainted compound
- While Thistle UniFinish will adhere to the painted surface, no-one can guarantee that failure within or between earlier layers won't occur, e.g. between texture compound and the original substrate, when more weight of plaster is applied.
Please refer to WHITE BOOK Chapter 07 Section 02 Page 04 and Page 07 for further details.


Documentation Center
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Model integrated circuit multiplier
Integrated Circuits
The Multiplier block models an integrated circuit multiplier. The block implements the following equation, which defines the voltage applied to the output port:
where X1, X2, Y1, Y2, Z1, Z2 are the voltages presented at the input ports, A is the gain, and K is the scale factor.
In a typical multiplication circuit, the output is fed back into input Z1, which results in the following gain (assuming that A is large):
The value of the scale factor K is usually altered by an external resistor bias network. The Multiplier block implements K as an internal gain, and the external bias network is not necessary for system simulation. A typical value for K is 10, with a typical adjustment down to 3.
You can use the Multiplier block to implement a number of other functions, as well as multiplication. Examples include division, squares, and square roots. For example circuits, consult manufacturer datasheets.
The following figure shows the internal model structure of the Multiplier block. It includes the Band-Limited Op-Amp block to model finite bandwidth and slew-rate limiting.
The next figure shows one of the differential subsystem blocks. All three differential subsystem blocks are identical in structure.
Basic Assumptions and Limitations
The Multiplier block has the following limitations:
 - Only differential limiting of the inputs is implemented. You must ensure that the absolute values of the inputs you use keep the actual device operating in its linear region.
 - Output current is such that the integrated circuit is operating in the linear I-V region, which can be approximated by a voltage source plus a series output resistance.
 - Input offset voltage is not modeled, and the input voltage-current relationship is treated as linear within the differential signal voltage range.
Dialog Box and Parameters
Main Tab
Scaling factor, K
The scaling factor K in the equation that defines output voltage. Datasheets sometimes refer to it as the scale factor, or SF. The default value is 10 V.
Gain, A
The gain of the internal operational amplifier, corresponding to the gain A in the equation that defines output voltage. The default value is 3e3.
Inputs Tab
Differential resistance, Rin
Each of the differential inputs is approximated as a linear resistor with value Rin. Set this value to the datasheet value for differential resistance. The default value is 1e7 Ω.
Differential signal voltage range
This value, Vdiff_max, is used to limit the magnitude of each of the three differential input voltages. Set this value to the datasheet value for differential signal voltage range. The default value is 10 V.
Outputs Tab
Output resistance, Rout
The multiplier output stage is modeled as a voltage source plus series resistor inside the Band-Limited Op-Amp block. This parameter specifies the value of this series resistor. The default value is 0.1 Ω.
Minimum output, Vmin
The lower limit of the output voltage. The default value is -11 V.
Maximum output, Vmax
The upper limit of the output voltage. The default value is 11 V.
Maximum slew rate, Vdot
The maximum positive or negative rate of change of output voltage magnitude. The default value is 20 V/μs.
Bandwidth, f
The bandwidth of the Band-Limited Op-Amp block. The default value is 1 MHz.
Initial output voltage, V0
The value of the initial Multiplier block output if the Start simulation from steady-state option is not selected in the Solver block. The default value is 0 V.
The block has six electrical conserving ports that serve as signal input ports and one electrical conserving port that outputs the multiplied signal.
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text: "Peak Flow technique" with Wright meter and Fleisch pneumotachograph spirometer and conversion to new EU scale. Comparison of PEF measurements using "Peak Flow technique" on Wright meter (closed square symbols) or Fleisch pneumotachograph spirometer (circles). The open squares are Wright values converted to the new EU scale. The values shown are the best of two measurements with each technique. Patients are arranged on the basis of increasing PEF measured using the Wright meter.


Improving lives. Improving the environment. Improving communities.
At Frahm Farmland, we believe that our goals as farmers should be about more than just the bottom line. They should be about contributing to the world around us and leaving our communities and the lives we touch better than how we found them.
It is with that in mind that we consistently make it a priority to positively impact local organizations, families and businesses while implementing the most competitive, profitable and sustainable farming practices that we can. As a 6th generation family farm, we understand and value the importance of community and will always keep that at the forefront of our operations.


American versus Mexican Culture
Hugh Fox San Antonio Collage
Objective: The student will discuss American versus Mexican Culture.
This is an application of the Fox Cultural Lesson Plan System. The student will be able to discuss historical, etiquette, traditional culture and pop culture approaches to understanding Mexican culture.
1) What happened to the Aztecs?
2) Describe the Mexican-American War.
3) Describe Manifest Destiny.
4) Describe the Mexican Revolution.
5) What is NAFTA?
6) How has Mexican history shaped Mexican attitudes towards the US?
7) Describe Mexican business etiquette.
8) What are some traditional dishes in Mexico?
List of Mexican dishes
9) What is the difference between Tex-Mex and Mexican food?
Tex Mex vs Mexican
Mexican People Try Taco Bell For The First Time
Do you think the menu below is for a Tex-Mex or Mexican restaurant?
Mexican Menu
10) What is a margarita?
or do it the Tex-Mex way!
11) Describe mariachi music.
12) What is lucha libre?
13) What are some of the differences between lucha libre and World Wrestling Entertainment (WWE)?
14) What is a telenovela?
15) What is the Mexican yell?
How To Do The Mexican Grito This Cinco de Mayo
Los Mejores Gritos Mexicanos
Worksheet at Scribd:
The students will take notes about a lecture using the table below with a Mexican Culture worksheet.
A Nomothetic Approach to Mexican Culture
mexican versus american culture-001
mexican versus american culture-002
mexican versus american culture-003
WereVerse Universe Baby!
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text:
The Innosilicon A4+ LTCMaster is a ASIC Scrypt algorithm miner from Innosilicon with a maximum hashrate of 620Mh/s and power consumption of 750W. It has a hashing efficiency of 0.82667 MH/J.
|Mineable Coins Scrypt|
|Colin Percival invented the Scrypt algorithm as the online service's cryptoprotection to keep UNIX-like OS backup copies. The scrypt algorithm's working principle is that it artificially complicates the selection of options for solving a cryptographic task by filling it with "noise." This noise is generated randomly by numbers the scrypt algorithm refers to, increasing the time of work.


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FreeBSD Manual Pages

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TEST(1) FreeBSD General Commands Manual TEST(1)
NAME
 test, [ -- condition evaluation utility
SYNOPSIS
 test expression
 [ expression ]
DESCRIPTION
 The test utility evaluates the expression and, if it evaluates to true,
 returns a zero (true) exit status; otherwise it returns 1 (false). If
 there is no expression, test also returns 1 (false).
 All operators and flags are separate arguments to the test utility.
 The following primaries are used to construct expression:
 -b file True if file exists and is a block special file.
 -c file True if file exists and is a character special file.
 -d file True if file exists and is a directory.
 -e file True if file exists (regardless of type).
 -f file True if file exists and is a regular file.
 -g file True if file exists and its set group ID flag is set.
 -h file True if file exists and is a symbolic link. This operator
 is retained for compatibility with previous versions of
 this program. Do not rely on its existence; use -L
 instead.
 -k file True if file exists and its sticky bit is set.
 -n string True if the length of string is nonzero.
 -p file True if file is a named pipe (FIFO).
 -r file True if file exists and is readable.
 -s file True if file exists and has a size greater than zero.
 -t file_descriptor
 True if the file whose file descriptor number is
 file_descriptor is open and is associated with a terminal.
 -u file True if file exists and its set user ID flag is set.
 -w file True if file exists and is writable. True indicates only
 that the write flag is on. The file is not writable on a
 read-only file system even if this test indicates true.
 -x file True if file exists and is executable. True indicates only
 that the execute flag is on. If file is a directory, true
 indicates that file can be searched.
 -z string True if the length of string is zero.
 -L file True if file exists and is a symbolic link.
 -O file True if file exists and its owner matches the effective
 user id of this process.
 -G file True if file exists and its group matches the effective
 group id of this process.
 -S file True if file exists and is a socket.
 file1 -nt file2
 True if file1 exists and is newer than file2.
 file1 -ot file2
 True if file1 exists and is older than file2.
 file1 -ef file2
 True if file1 and file2 exist and refer to the same file.
 string True if string is not the null string.
 s1 = s2 True if the strings s1 and s2 are identical.
 s1 != s2 True if the strings s1 and s2 are not identical.
 s1 < s2 True if string s1 comes before s2 based on the binary value
 of their characters.
 s1 > s2 True if string s1 comes after s2 based on the binary value
 of their characters.
 n1 -eq n2 True if the integers n1 and n2 are algebraically equal.
 n1 -ne n2 True if the integers n1 and n2 are not algebraically equal.
 n1 -gt n2 True if the integer n1 is algebraically greater than the
 integer n2.
 n1 -ge n2 True if the integer n1 is algebraically greater than or
 equal to the integer n2.
 n1 -lt n2 True if the integer n1 is algebraically less than the inte-
 ger n2.
 n1 -le n2 True if the integer n1 is algebraically less than or equal
 to the integer n2.
 If file is a symbolic link, test will fully dereference it and then eval-
 uate the expression against the file referenced, except for the -h and -L
 primaries.
 These primaries can be combined with the following operators:
 ! expression True if expression is false.
 expression1 -a expression2
 True if both expression1 and expression2 are true.
 expression1 -o expression2
 True if either expression1 or expression2 are true.
 ( expression )
 True if expression is true.
 The -a operator has higher precedence than the -o operator.
 Some shells may provide a builtin test command which is similar or iden-
 tical to this utility. Consult the builtin(1) manual page.
GRAMMAR AMBIGUITY
 The test grammar is inherently ambiguous. In order to assure a degree of
 consistency, the cases described in the IEEE Std 1003.2 (''POSIX.2''),
 section D11.2/4.62.4, standard are evaluated consistently according to
 the rules specified in the standards document. All other cases are sub-
 ject to the ambiguity in the command semantics.
 In particular, only expressions containing -a, -o, ( or ) can be ambigu-
 ous.
EXIT STATUS
 The test utility exits with one of the following values:
 0 expression evaluated to true.
 1 expression evaluated to false or expression was missing.
 >1 An error occurred.
EXAMPLES
 Implement test FILE1 -nt FILE2 using only POSIX functionality:
 test -n "$(find -L -- FILE1 -prune -newer FILE2 2>/dev/null)"
 This can be modified using non-standard find(1) primaries like -newerca
 to compare other timestamps.
COMPATIBILITY
 For compatibility with some other implementations, the = primary can be
 substituted with == with the same meaning.
SEE ALSO
 builtin(1), expr(1), find(1), sh(1), stat(1), symlink(7)
STANDARDS
 The test utility implements a superset of the IEEE Std 1003.2
 (''POSIX.2'') specification. The primaries <, ==, >, -ef, -nt, -ot, -G,
 and -O are extensions.
BUGS
 Both sides are always evaluated in -a and -o. For instance, the writable
 status of file will be tested by the following command even though the
 former expression indicated false, which results in a gratuitous access
 to the file system:
 [ -z abc -a -w file ]
 To avoid this, write
 [ -z abc ] && [ -w file ]
FreeBSD 11.1 June 1, 2013 FreeBSD 11.1
NAME | SYNOPSIS | DESCRIPTION | GRAMMAR AMBIGUITY | EXIT STATUS | EXAMPLES | COMPATIBILITY | SEE ALSO | STANDARDS | BUGS
Want to link to this manual page? Use this URL:
<_URL_
home | help


$u_y$ by an angle of $-\pi/2$ radians.
norm(rotate(diffy(u), -pi/2)-diffx(u))
ans =
We observe that $u_{xx} + u_{yy}$ is a scalar multiple of $u$. We can compare Diskfun's result with the computation $-\lambda u$, where $\sqrt{\lambda} = 7.58834243450380$.
plot(lap(u)), axis off
title('Laplacian of u')
lambda = (7.58834243450380)^2;
norm(-lambda*u - lap(u))
ans =
16.3 Poisson equation
We can use Diskfun to compute smooth solutions to the Poisson equation on the disk. In this example, we compute the solution $v(\theta, \rho)$ for the Poisson equation with a Dirichlet boundary condition: we seek $v$ such that $$ \nabla^2 v = f, \qquad v(\theta, 1) = 1,$$ where $(\theta, \rho) \in [-\pi, \pi] \times [0, 1]$ and $f = \sin \left( 21 \pi \left( 1 + \cos( \pi \rho) \right) \rho^2-2\rho^5\cos \left( 5(t-.11)\right) \right)$. The solution is returned as a diskfun, so we can immediately plot it, evaluate it, find its zero contours, or perform other operations. Currently, Diskfun requires the user to specify the number of 2D coefficients to be solved for; in this case, we choose a coefficient matrix of size $256 \times 256$.
f = @(t,r) sin(21*pi*(1+cos(pi*r)).*(r.^2-2*r.^5.*cos(5*(t-0.11))));
rhs = diskfun(f, 'polar');
bc = @(t) 0*t+1;
v = diskfun.poisson(f, bc, 256)
v =
 diskfun object
 domain rank vertical scale
 unit disk 21 1
plot( rhs ), axis off
title( 'f' ), snapnow
plot( v ), axis off
title( 'v' )
16.4 Vector calculus
Since the introduction of Chebfun2, Chebfun has supported computations with vector-valued functions, including functions in 2D (Chebfun2v), 3D (Chebfun3v), and spherical geometries (Spherefunv, Ballfunv). Similarly, Diskfunv allows one to compute with vector-valued functions on the disk. Currently, there are dozens of commands available in Diskfunv, including vector-based algebraic commands such as cross, as well as commands that map vector-valued functions to scalar-valued functions (e.g., dot, curl, div and jacobian) and vice-versa (e.g., grad), and commands for performing calculus with vector fields (e.g., laplacian).
In this example, we create a diskfun consisting of a difference of two Gaussian functions, and then compute its gradient. The result is returned as a vector-valued object called a diskfunv, with a lower case 'd'.
psi = @(x,y) 5*exp(-10*(x+.2).^2-10*(y+.4).^2)...
 -5*exp(-10*(x-.2).^2-10*(y-.2).^2) + 5*(1-x.^2-y.^2)-20;
f = diskfun( psi );
u = grad(f)
u =
diskfunv object containing
 diskfun object
 domain rank vertical scale
 unit disk 27 18
 diskfun object
 domain rank vertical scale
 unit disk 25 20
The vector-valued function $\mathbf{u}$ consists of two components, ordered with respect to unit vectors in the directions of $x$ and $y$, respectively. Each of these is stored as a diskfun. We can view the vector field using a quiver plot:
plot(f), hold on
quiver(u, 'k'), axis off, hold off
Once a diskfunv object is created, dozens of overloaded commands can be applied to it. For example, here is a contour plot of the divergence of $\mathbf{u}$.
D = div( u );
contour(D,10), hold on
Since $\mathbf{u}$ is the gradient of $f$, we can verify that $\nabla \cdot \mathbf{u} = \nabla^2 f$:
norm( div(u) - lap(f) )
ans =
Additionally, since $\mathbf{u}$ is a gradient field, $\nabla \times \mathbf{u} = 0$.
We can verify this with the curl command.
v = curl(u);
norm( v )
ans =
Diskfunv objects can be created by calling the constructor directly and supplying function handles or diskfuns for each component, or by vertically concatenating two diskfuns. Here, we demonstrate this by forming a diskfunv $\mathbf{v}$ that represents the surface curl for a scalar-valued function $g$, i.e, $\nabla \times [0, 0, g]$.
g = diskfun( @(x,y) cosh(.25.*(cos(5*x)+sin(4*y.^2)))-2 );
dgx = diffx( g );
dgy = diffy( g );
v = diskfunv(dgy, -dgx); % call constructor
norm(v - [dgy; -dgx]) % equivalent to vertical concatenation
ans =
plot( g ), hold on
quiver(v, 'w'), axis off
title( 'The numerical surface curl of g' ), hold off
This construction is equivalent to using the command curl on the scalar function $g$:
norm( v - curl(g) )
ans =
To see all commands available for vector-valued functions in Diskfun, type methods diskfunv in the MATLAB command line.
16.5 Constructing a diskfun
The above sections describe how to use Diskfun, and this section provides a brief overview of how the algorithms in Diskfun work. This can be useful for understanding various aspects of approximation involving functions on the disk. More details can be found in [Townsend, Wilber & Wright, 2016b], and also in the closely related Spherefun part (Chapter 17) of the guide.
Like Chebfun2 and Spherefun, Diskfun uses a variant of Gaussian elimination (GE) to form low rank approximations to functions. This often results in a compressed representation of the function, and it also facilitates the use of highly efficient algorithms that work primarily on sets of 1D functions related to the approximant.
To construct a diskfun from a function $f$, we consider an extended version of $f$, denoted by $\tilde{f}$, which is formed by taking $f(\theta, \rho)$ and letting $\rho$ range over $[-1, 1]$, as opposed to $[0, 1]$. This is the disk analogue of the so-called double Fourier sphere method discussed in Chapter 17 (also, see [Fornberg, 1998] and [Trefethen, 2000]). The function $\tilde{f}$ has a special structure, referred to as a blockmirror-centrosymmetric (BMC) structure. By forming approximants that preserve the BMC structure of $\tilde{f}$, smoothness near the origin is guaranteed.
To see the BMC structure, we construct a diskfun f and use the cart2pol command:
f = @(x,y) cos(2*((3*sin(2*x)+5*sin(y))))-.5*sin(x-y);
f = diskfun(f);
plot(f), axis off
tf = cart2pol(f, 'cdr')
plot(tf), view(2)
title('The BMC function associated with f')
tf =
 chebfun2 object (trig in x)
 domain rank corner values
[-3.1, 3.1] x [ -1, 1] 26 [0.26 0.26 1.1 1.1]
vertical scale = 1.5
A structure-preserving method of GE (see [Townsend, Wilber & Wright, 2016b]) adaptively selects a collection of 1D circular and radial "slices" that are used to approximate $\tilde{f}$. Each circular slice is a periodic function in $\theta$, and is represented by a trigonometric interpolant (or trigfun, see Chapter 11). Each radial slice, a function in $\rho$, is represented as a chebfun. These slices form a low rank representation of $f$, \begin{equation} \label{eq:lra} f(\theta, \rho) \approx \sum_{j=1}^{n} d_jc_j(\rho)r_j(\theta), \end{equation} where ${ d_j }_{j=1}^{n}$ are pivot values associated with the GE procedure.
The plot command can be used to display the "skeleton" of f: the locations of the slices that were adaptively selected and sampled during the GE


What to do when you find a banded bird:
Sometimes, when you're out in the field and looking closely at birds, you may get lucky and find a bird that has a band on it's leg. You are suddenly presented with a wonderful opportunity to contribute to scientific research! But how do you do that exactly?
If you see a band on a small passerine, it's highly unlikely that you'll be able to read the numbers stamped on the bird correctly and accurately. But if the bird is larger, a goose, or a gull perhaps, you have a shot at getting the letters and numbers imprinted on the band. If the bird has died, and you can retrieve the band, you most likely will be able to record the number precisely.
If you are able to get a photo of the bird, that can be of great use. Sometimes it's easier to get a read on a sharp photo of the bird, but as the number on the band will wrap all the way around the leg of the bird, try to get shots from several different angles. That will increase the chance that you'll be able to get a read of the complete band number. Also, the photos will help researchers gather more data about the bird if they can get a good look at the images.
Once you have the band number recorded, you can report this information to the US Geological Survey's (USGS) Bird Banding Laboratory in Maryland. Here's a link to report a banded bird online:
The researcher who banded the bird will get notification, and you can receive a certificate of appreciation that will tell you where the bird was banded and the age of the bird at the time the band was placed. Your contribution of this vital information will contribute greatly to our understanding of avian movement and aging.
Important data you should collect include:
 - The band number with all digits. (This is the most vital!)
 - The location you found the band, date and time.
 - The location, as exactly as you can.
 - The species of the bird
 - The condition of the bird
 - Any other details you can observe about the bird and it's activities
 - Photos from several angles, if possible!


Take the 2-minute tour ×
Let $F$ be a $100 \times 100$ DFT matrix, and $U$ be a diagonal matrix with its diagonal entries being all positive, denoted by $U=\mathrm{diag}(u_1, u_2,\cdots, u_{100})$. My question is:
Under which conditions on $U$ will the resulting matrix $FUF^\ast$ be circulant (where $F^\ast$ is the conjugate transpose of $F$)?
share|improve this question
There might be; the Fourier transform of a diagonal matrix has nice structure, being complex-symmetric and constant along its antidiagonals (Hankel)... – Ｊ. Ｍ. May 9 '12 at 3:16
Well, it is not too hard to show that if $U$ is diagonal with real elements, then $F U F^*$ is real iff all diagonal elements of $U$ are exactly the same, ie, $U$ is a real multiple of the identity. – copper.hat May 9 '12 at 5:22
...and you have $$\mathbf U\mathbf D\mathbf U^\ast=\begin{pmatrix}0&-\frac12-\frac{i}{2\sqrt 3}&-\frac12+\frac{i}{2\sqrt 3}\\-\frac12+\frac{i}{2\sqrt 3}&0&-\frac12-\frac{i}{2\sqrt 3}\\-\frac12-\frac{i}{2\sqrt 3}&-\frac12+\frac{i}{2\sqrt 3}&0\end{pmatrix}$$ – Ｊ. Ｍ. May 9 '12 at 6:18
I might be wrong but I think that every circulant matrix is diagonalized by the DFT matrix so something like $F_n C F_n^* = D$. Using this I'm thinking that you can assume that the result of your computation will be circulant as well and hence you have essentially $n$ (=100) terms to compute. In J.M.'s example, the matrix is circulant. [c0 c1 c2; c2 c0 c1; c1 c2 c0] – tibL May 9 '12 at 8:33
I think that, up to a normalisation, the (a,b) element of the product is the DFT of u at a-b. – dmuir May 9 '12 at 9:18
show 10 more comments
1 Answer
up vote 1 down vote accepted
After seeing this article, I see that one can in fact easily build a circulant matrix, given its eigenvalues, and vice-versa. (In short: $\mathrm F \mathrm U \mathrm F^\ast$ is always circulant.)
Briefly, given the eigenvalues $u_1,u_2,\dots,u_N$, one simply needs to take the inverse discrete Fourier transform
$$a_{1,j}=\frac1{N}\sum_{k=0}^{N-1}u_{k+1}\exp\left(\frac{2\pi i(j-1)k}{N}\right)$$
to yield the first row of the circulant matrix $\mathbf A=\mathrm F \mathrm U \mathrm F^\ast$, after which the successive rows of $\mathbf A$ are easily generated. Conversely, the eigenvalues of $\mathbf A$ are generated by taking the DFT of the first row of $\mathbf A$.
Here's a Mathematica demonstration:
n = 100;
vec = Sort[RandomReal[{0, 30}, {n}], Greater];
ma = NestList[RotateRight,
 InverseFourier[vec, FourierParameters -> {1, -1}], n - 1];
Eigenvalues[ma] - vec // Chop
share|improve this answer
Thanks! It is very clear that a circulant matrix can be diagonalized via DFT, and vice-versa. – John Smith May 9 '12 at 15:19
add comment
Your Answer


Classic Car Appraisal Services in Highlands, Texas
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Highlands United States
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Facts about Highlands
The community was named Highlands because the east bank of the San Jacinto River, where Highlands is located, has a higher elevation than the west bank of the river. By 1908 Highlands became a station on the Beaumont, Sour Lake and Western Railway. A post office opened in 1929. Highlands incorporated in 1930, but its charter was voided, leaving Highlands as unincorporated again. In the 1930s Highlands had 20 businesses and its population decreased from 350 to 200. The 1936 Harris County highway map indicated two churches, a factory, a school, and a sawmill in Highlands. Highlands housed military members and war plant personnel during World War II. By 1948 Highlands had 3,000 residents and 75 businesses. In the 1950s local business decreased and the population decreased to 2,723. A 1956 attempt for Highlands to incorporate did not pass. In the 1960s Highlands had a canning sales company and an industrial chemical company. In the early 1960s Highlands had 4,336 residents and 82 businesses. In 1965 W. O. Hutson built the Double Trouble Youth Rodeo Arena. In the early 1970s Highlands had 3,462 residents and 66 businesses. By 1977 Highlands had 5,000 residents; in 1989 Highlands reported the same population. In 1990 Highlands had an estimated population of 6,632.
According to the United States Census Bureau, the CDP has a total area of 6.5 square miles (16.9 km2), of which 4.9 square miles (12.6 km2) is land and 1.7 square miles (4.3 km2), or 25.18%, is water. Highlands is located on the banks of the San Jacinto River and the Houston Ship Channel. The majority of the land in Highlands is on a high river bank. The historic Lynchburg Ferry is nearby.
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