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BenchmarkA benchmark is a point of reference for a measurement. The term originates from the chiseled horizontal marks that surveyors made into which an angle-iron could be placed to bracket (bench) a levelling rod, thus ensuring that the levelling rod can be repositioned in the exact same place in the future.
- For the use of benchmarks in surveying (the origin of the term) see Benchmark (surveying)
- For the use of benchmarks in computing see Benchmark (computing)
- For the use of benchmarks in management see Benchmarking
- For the geolocating game similar to geocaching see Benchmarking (geolocating)
ChiselA chisel is a tool for carving and/or cutting a hard material such as wood, stone, or metal. A chisel, typically made of hardened or tempered steel, or more rarely, common steel, consists of a sharpened end (called the blade) attached to a straight handle. The handle and blade of some types of chisels are made in one piece.
In use, a worker forces the chisel into the material to cut the material. The driving force may be manually applied or applied using a mallet or hammer. In industrial use, a hydraulic ram or falling weight ('triphammer') drives the chisel into the material to be cut.
A gouge, one type of chisel, is used, particularly in woodworking and sculpture, to carve small pieces from the material. Gouges are most often used in creating concave surfaces. A gouge has a 'U'-shaped cross-section.
Types
Chisels have a wide variety of uses. Many types of chisels have been devised, each specially suited to its intended use. Different types of chisels may be constructed quite differently, in terms of blade width or length, as well as shape and hardness of blade. They may have wooden handles attached or may be made entirely of one piece of metal.
Woodworking chisels
Woodworking chisels range from quite small hand tools for tiny detail, to large chisels used to remove big sections of wood, in 'roughing out' the shape of a pattern or design. Typically, in woodcarving, one starts with a larger tool, and gradually progressing to smaller tools to finish the detail. One of the largest types of chisel is the framing slick, used in timber frame construction.
Lathe tools
A lathe tool can be a woodworking chisel designed to cut wood as it is spun on a lathe. These tools have longer handles for more leverage, needed to counteract the tendency of the tool to react to the downward force of the spinning wood being cut or carved.
Metalworking chisels
Chisels used in metal work can be divided into two main categories, hot chisels, and cold chisels. A hot chisel is used to cut metal that has been heated in a forge to soften the metal.
Cold chisel
forge
A cold chisel is a tool made of tempered steel used for cutting 'cold' metals, meaning that they are not used in conjunction with heating torches, forges, etc. This tool is also commonly referred to by the misnomer 'coal chisel'. Because cold chisels are used to form metal, they have a less-acute angle to the sharp portion of the blade than a woodworking chisel. This gives the cutting edge greater strength at the expense of sharpness.
Cold chisels come in a variety of sizes, from fine engraving tools that are tapped with very light hammers, to massive tools that are driven with sledgehammers.
Hardy chisel
A Hardy Chisel is a type of hot chisel with a square shank, which is held in place with the cutting edge facing upwards by placing it in an anvil's Hardy hole. The hot workpiece cut is then placed over the hardy, and struck with a hammer. The hammer drives the chisel into the hot metal, allowing it to be snapped off with a pair of tongs.
Stone chisels
Stone chisels are used to carve or cut stone, bricks or concrete slabs. To cut, as opposed to carve, a bolster chisel is used; a wide, flat blade that is tapped along the cut line to produce a groove, then hit hard in the centre to crack the stone. To increase the force, stone chisels are often hit with Lump hammers, a heavier type of hammer.
See also
- Broach
- Burin
External links
- [http://www.woodworking-free.com/sharpening/2.php Sharpening Chisels and Planes] provides detailed instructions on how to properly sharpen chisels.
Category:Mechanical hand tools
Category:Woodworking hand tools
Category:Metalworking
Benchmark (surveying):This article is about the use of benchmarks in surveying, for other uses see Benchmark
Benchmark
Benchmark
Benchmark
Benchmark
A benchmark is a point of reference for a measurement. In surveying a benchmark is set by a surveyor to mark a point of known vertical elevation. These marks may be chiseled into a wall or they may be small brass or aluminium disks, concrete posts, iron pins or bolts that are permanently attached to a stable foundation. In all cases the mark is used by subsequent surveyors to establish the elevation of nearby points.
The term benchmark originates from the chiseled horizontal marks that surveyors made into which an angle-iron could be placed to bracket (bench) a levelling rod, thus ensuring that the levelling rod can be repositioned in the same place in the future. These marks were usually highlighted with a chiseled arrow below the horizontal line.
Other types of survey marks
Triangulation points are marks used to establish horizontal position. These points may be marked by disks similar to benchmark disks. Often prominent features on buildings such as the tip of a church spire or chimney stack are also used for triangulation. In the United Kingdom triangulation points are often set in small concrete markers called trig points. As well as functioning as a triangulation point, trig points also have a benchmark set into the side of the monument.
Agencies responsible for benchmarks
Benchmarks are typically set ("monumented") by a government agency or a private survey firm.
Government agencies that set and maintain benchmarks include:
- France
- Institut Géographique National ([http://fr.wikipedia.org/wiki/Institut_g%C3%A9ographique_national IGN on Wiki FR])
- United Kingdom
- The Ordnance Survey
- United States
- The National Geodetic Survey (NGS)
- The United States Geological Survey (USGS)
- Japan
- Geographical Survey Institute (GSI)
See also
- In the recreational activity of benchmarking, participants search for benchmarks using a handheld GPS receiver and log those they find.
External links
- [http://www.dustyjacket.com/benchmarks.html photos of benchmarks], mainly in the US.
- [http://www.geocaching.com/mark/ Benchmarking using a GPS]
Category:Surveying
Benchmark (computing):This article is about the use of benchmarks in computing, for other uses see benchmark.
In computing, a benchmark is the result of running a computer program, or a set of programs, in order to assess the relative performance of an object, by running a number of standard tests and trials against it. The term, benchmark, is also commonly used for specially-designed benchmarking programs themselves. Benchmarking is usually associated with assessing performance characteristics of computer hardware, for example, the floating point operation performance of a CPU, but there are circumstances when the technique is also applicable to software. Software benchmarks are, for example, run against compilers or database management systems.
Benchmarks provide a method of comparing the performance of various subsystems across different chip/system architectures.
Purpose
As computer architecture advanced, it became more and more difficult to compare the performance of various computer systems simply by looking at their specifications. Therefore, tests were developed that could be performed on different systems, allowing the results from these tests to be compared across different architectures. For example, Intel Pentium 4 processors have a higher hertz rating than AMD Athlon XP processors for the same computational speed, in other words a 'slower' AMD processors could be as fast on benchmark tests as a higher hertz rated Intel processors.
Benchmarks are designed to mimic a particular type of workload on a component or system. "Synthetic" benchmarks do this by specially-created programs that impose the workload on the component. "Application" benchmarks, instead, run actual real-world programs on the system. Whilst application benchmarks usually give a much better measure of real-world performance on a given system, synthetic benchmarks still have their use for testing out individual components, like a hard disk or networking device.
Benchmarks are particularly important in semiconductor microprocessor design, giving processor architects the ability to measure and make tradeoffs in microarchitectural decisions. For example, if a benchmark extracts the key algorithms of an application, it will contain the performance-sensitive aspects of that application. Running this much smaller "snippet" on a cycle-accurate simulator, can give clues on how to improve performance.
Prior to 2000, computer and microprocessor architects used SPEC to do this, although SPEC's Unix-based benchmarks were quite lengthy and thus unwieldy to use intact. Since 1998 and the founding of EEMBC by Markus Levy and 12 semiconductor company representatives [http://www.eembc.org Embedded Microprocessor Benchmark Consortium], with its focus on embedded benchmarking, architects can run much smaller and more focused algorithm-based benchmarks. EEMBC is unique in that its benchmark scores and benchmark reports are certified by an independent third party, the [http://www.ebenchmarks.com EEMBC Certification Laboratory] headed by Alan R. Weiss. EEMBC's next great challenge is benchmarking power consumption and energy utilization by processors as more and more embedded processors go into low-power environments such as cellular phones and other mobile applications.
Computer manufacturers have a long history of trying to set up their systems to give unrealistically high performance on benchmark tests that is not replicated in real usage. For instance, during the 1980s some compilers could detect a specific mathematical operation used in a well-known floating-point benchmark and replace the operation with a mathematically-equivalent operation that was much faster. However, such a transformation was rarely useful outside the benchmark until the mid-1990s, when RISC and VLIW architectures emphasized the importance of compiler technology as it related to performance. Benchmarks are now regularly used by compiler companies to improve not only their own benchmark scores, but real application performance.
Manufacturers commonly report only those benchmarks (or aspects of benchmarks) that show their products in the best light. They also have been known to mis-represent the significance of benchmarks, again to show their products in the best possible light. Taken together, these practices are called bench-marketing. See [http://www6.tomshardware.com/cpu/20041221/cpu_charts-12.html this article] for an excellent example of how application benchmarks can differ significantly from synthetic benchmarks.
Users are recommended to take benchmarks, particularly those provided by manufacturers themselves, with ample quantities of salt unless the benchmarks are certified and relate directly to a recognizable application workload. Ideally benchmarks should only substitute for real applications if the application is unavailable, or too difficult or costly to port, to a specific processor or computer system. If performance is really critical, the only benchmark that matters is the actual workload that the system is to be used for. If that is not possible, benchmarks that resemble real workloads as closely as possible should be used, and even then used with skepticism unless independently certified. It is quite possible for system A to outperform system B when running program "furble" on workload X (the workload in the benchmark), and the order to be reversed with the same program on your own workload.
Challenges
Benchmarking is not easy and often involves several iterative rounds in order to arrive at predictable, useful conclusions. Interpretation of benchmarking data is also extraordinarily difficult. Here is a partial list of common challenges:
- Vendors tend to tune their products specifically for industry-standard benchmarks. Use extreme caution in interpreting such results.
- Benchmarks generally do not give any credit for any qualities of service aside from raw performance. Examples of unmeasured qualities of service include security, availability, reliability, execution integrity, serviceability, scalability (especially the ability to quickly and nondisruptively add or reallocate capacity), etc. There are often real trade-offs between and among these qualities of service, and all are important in business computing.
- Benchmarks do not measure TCO.
- Benchmarks seldom measure real world performance of mixed workloads — running multiple applications concurrently in a business context. For example, IBM's mainframe servers (System z9) excel at mixed workload, but industry-standard benchmarks don't tend to measure the strong I/O and large/fast memory design such servers require. (Most other server architectures dictate fixed function/single purpose deployments, e.g. "database servers" and "Web application servers" and "file servers," and measure only that. The better question is, "What more computing infrastructure would I need to fully support all this extra workload?")
- Vendor benchmarks tend to ignore requirements for test and QA computing capacity. Vendors only like to report what might be narrowly required for production capacity in order to make their initial acquisition price seem as low as possible.
- Benchmarks are having trouble adapting to widely distributed servers, particularly those with extra sensitivity to network topologies. The emergence of grid computing, in particular, is making benchmarking that much more difficult since some workloads are "grid friendly" and others definitely aren't.
- Users can have very different perceptions of performance than benchmarks might otherwise suggest. In particular, users appreciate predictability — servers that always meet or exceed SLAs. Benchmarks tend to emphasize mean scores (IT perspective) rather than low standard deviations (user perspective).
- Many server architectures degrade dramatically at high (near 100%) levels of utilization — "fall off a cliff" — and benchmarks should (but often don't) take that factor into account. Vendors, in particular, tend to publish server benchmarks at continuous ~80% utilization — a totally unreal situation.
Types of benchmarks
#Real program
#
- word processing software
#
- tool software of CDA
#
- user's application software (MIS)
#Kernel
#
- contains key codes
#
- normally abstracted from actual program
#
- popular kernel: Livermore loop
#
- linpack benchmark (contains basic linear algebra subroutine written in FORTRAN language)
#
- results are represented in MFLOPS
#Toy Benchmark
#
- user can program it and use it to test computer's basic components
#Synthetic Benchmark
#
- Procedure for programming synthetic Bench mark
#
- take statistics of all type of operations from plenty of application programs
#
- get proportion of each operation
#
- write a program based on the proportion above
#
- Types of Synthetic Benchmark are:
#
- Whetstone
#
- Dhrystone
#
- Its results are represented in KWIPS (kilo whetstone instructions per second). It is not suitable for measuring pipeline computers.
Common benchmarks
- HINT
- Fhourstones
- Dhrystone
- Whetstone
- Standard Performance Evaluation Corporation (SPEC)
- BAPco
- 3DMark
- Khornerstone
- TPC-C
- Linpack
- Aquamark
- John the Ripper
- NAS benchmarks
- The BRL-CAD Benchmark
windows benchmarks
- SiSoftware Sandra
- BAPCo SysMark
- Whetstone (benchmark)
- Futuremark PCMark
See also
- Benchmark Generation Modeling Language
- benchmarking (business perspective)
Category:Computer benchmarks
ja:ベンチマーク
Benchmarking:For the geolocating game, see benchmarking (geolocating). For other uses of the term 'benchmark' see benchmark.
Benchmarking (also "best practice benchmarking" or "process benchmarking") is a process used in management and particularly strategic management, in which organizations evaluate various aspects of their processes in relation to best practice, usually within their own sector. This then allows organizations to develop plans on how to adopt such best practice, usually with the aim of increasing some aspect of performance. Benchmarking may be a one-off event, but is often treated as a continuous process in which organizations continually seek to challenge their practices.
A process similar to benchmarking is also used in technical product testing and in land surveying. See the article benchmark for these applications.
Procedure
#Identify your problem areas - Because benchmarking can be applied to any business process or function, a range of research techniques may be required. They include: informal conversations with customers, employees, or suppliers; exploratory research techniques such as focus groups; or indepth marketing research, quantitative research, surveys, questionnaires, reengineering analysis, process mapping, quality control variance reports, or financial ratio analysis.
#Identify organizations that are leaders in these areas - Look for the very best in any industry and in any country. Consult customers, suppliers, financial analysts, trade associations, and magazines to determine which companies are worthy of study.
Cost of benchmarking
Benchmarking is a moderately expensive process, but most organisations find that it more than pays for itself. The three main types of costs are:
- Visit costs - This includes hotel rooms, travel costs, meals, a token gift, and lost labour time.
- Time costs - Members of the benchmarking team will be investing time in researching problems, finding exceptional companies to study, visits, and implementation. This will take them away from their regular tasks for part of each day so additional staff might be required.
- Benchmarking database costs - Organizations that institutionalize benchmarking into their daily procedures find it is useful to create and maintain a database of best practices and the companies associated with each best practice now.
Competitive benchmarking
Some authors call benchmarking "best practices benchmarking" or "process benchmarking". This is to distinguish it from what they call "competitive benchmarking". Competitive benchmarking is used in competitor analysis. When researching your direct competitors you also research the best company in the industry (even if it serves a different location or market segment and is therefore not a direct competitor). This benchmark company is then used as a standard of comparison when assessing your direct competition and yourself.
Collaborative benchmarking
Benchmarking, originally invented as a formal process by Rank Xerox, is usually carried out by individual companies. Sometimes it may be carried out collaboratively by groups of companies (eg subsidiaries of a multinational in different countries). One example is that of the Dutch municipally-owned water supply companies, which have carried out a voluntary collaborative benchmarking process since 1997 through their industry association VEWIN.
Advantages of Benchmarking
Benchmarking is a powerful management tool because it overcomes "paradigm blindness." Paradigm Blindness can be summed up as the mode of thinking, "The way we do it is the best because this is the way we've always done it." Benchmarking opens organizations to new methods, ideas and tools to improve their effectiveness. It helps crack through resistance to change by demonstrating other methods of solving problems than the one currently employed, and demonstrating that they work, because they are being used by others.
Consulting organizations that do benchmarking
- Global Best Practices [http://www.globalbestpractices.com/]
- Mummert Consulting AG
- Juran Institute
- Accenture
- A.T. Kearney
- Best Practices Benchmarking & Consulting Inc
- Pearce Mayfield [http://www.pearcemayfield.com/]
- Towers Perrin
- Benchmarking Partners, Inc
- International Benchmarking Clearinghouse
- Strategic Planning Institute Council on Benchmarking
- Benchmarking exchange
- Benchmarking Network
- American Productivity and Quality Center (APQC)
- FSmetrics
Category:Management
Benchmarking (geolocating)Benchmarking is a 'sport' in which participants individually go out and find benchmarks (also known as geodetic control points). They typically then log their finds online. Like geocaching, the activity has mainly become popular in the early years of the 21st century.
Many users use a GPS receiver to locate the known position of a benchmark, but it is also possible to find them without using GPS technology.
It is similar to geocaching and trigpointing.
External links
- [http://www.geocaching.com/mark/ Benchmarking using a GPS]
Category:Individual sports
Category:Outdoor locating games
Luettelo Ruotsin kunnistaTämä on aakkosellinen luettelo 290 nykyisestä Ruotsin kunnasta (2004).
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Hollowfaced Bat
Nycteridae is the family of slit-faced or hollow-faced bats. They are grouped in a single genus, Nycteris.
The bats are found in East Malaysia, Indonesia and many parts of Africa.
Classification
Most sources report 13 species. However 16 have been described. Those of indeterminate status are marked with "?" in the list below.
Familia Nycteridae Van der Hoeven
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