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Sampling Design
Sampling may refer to: *Sampling (signal processing), converting a continuous signal into a discrete signal * Sampling (graphics), converting continuous colors into discrete color components *Sampling (music), the reuse of a sound recording in another recording **Sampler (musical instrument), an electronic musical instrument used to record and play back samples *Sampling (statistics), selection of observations to acquire some knowledge of a statistical population *Sampling (case studies), selection of cases for single or multiple case studies * Sampling (audit), application of audit procedures to less than 100% of population to be audited *Sampling (medicine), gathering of matter from the body to aid in the process of a medical diagnosis and/or evaluation of an indication for treatment, further medical tests or other procedures. *Sampling (occupational hygiene), detection of hazardous materials in the workplace *Sampling (for testing or analysis), taking a representative portion of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sampling (signal Processing)
In signal processing, sampling is the reduction of a continuous-time signal to a discrete-time signal. A common example is the conversion of a sound wave to a sequence of "samples". A sample is a value of the signal at a point in time and/or space; this definition differs from the usage in statistics, which refers to a set of such values. A sampler is a subsystem or operation that extracts samples from a continuous signal. A theoretical ideal sampler produces samples equivalent to the instantaneous value of the continuous signal at the desired points. The original signal can be reconstructed from a sequence of samples, up to the Nyquist limit, by passing the sequence of samples through a type of low-pass filter called a reconstruction filter. Theory Functions of space, time, or any other dimension can be sampled, and similarly in two or more dimensions. For functions that vary with time, let ''S''(''t'') be a continuous function (or "signal") to be sampled, and let samp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chorionic Villus Sampling
Chorionic villus sampling (CVS), sometimes called "chorionic ''villous'' sampling" (as "villous" is the adjectival form of the word "villus"), is a form of prenatal diagnosis done to determine chromosomal or genetic disorders in the fetus. It entails sampling of the chorionic villus (placental tissue) and testing it for chromosomal abnormalities, usually with FISH or PCR. CVS usually takes place at 10–12 weeks' gestation, earlier than amniocentesis or percutaneous umbilical cord blood sampling. It is the preferred technique before 15 weeks. CVS was performed for the first time in Milan by Italian biologist Giuseppe Simoni, scientific director of Biocell Center, in 1983. Use as early as eight weeks in special circumstances has been described. It can be performed in a transcervical or transabdominal manner. Although this procedure is mostly associated with testing for Down syndrome, overall, CVS can detect more than 200 disorders. Indications Poss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Work Sampling
Work sampling is the statistical technique used for determining the proportion of time spent by workers in various defined categories of activity (e.g. setting up a machine, assembling two parts, idle…etc.). It is as important as all other statistical techniques because it permits quick analysis, recognition, and enhancement of job responsibilities, tasks, performance competencies, and organizational work flows. Other names used for it are 'activity sampling', 'occurrence sampling', and 'ratio delay study'. In a work sampling study, a large number of observations are made of the workers over an extended period of time. For statistical accuracy, the observations must be taken at random times during the period of study, and the period must be representative of the types of activities performed by the subjects. One important usage of the work sampling technique is the determination of the standard time for a manual manufacturing task. Similar techniques for calculating the standard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Sampling
Water quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through treatment of the water, can be assessed. The most common standards used to monitor and assess water quality convey the health of ecosystems, safety of human contact, extend of water pollution and condition of drinking water. Water quality has a significant impact on water supply and oftentimes determines supply options. Categories The parameters for water quality are determined by the intended use. Work in the area of water quality tends to be focused on water that is treated for potability, industrial/domestic use, or restoration (of an environment/ecosystem, generally for health of human/aquatic life). Human consumption Contaminants that may be in untreated water include microorganisms such as viruses, protozoa and bacteria; inorganic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theoretical Sampling
Theoretical sampling is a process of data collection for generating theory whereby the analyst jointly collects codes and analyses data and decides what data to collect next and where to find them, in order to develop a theory as it emerges. The initial stage of data collection depends largely on a general subject or problem area, which is based on the analyst's general perspective of the subject area. The initial decisions are not based on a preconceived theoretical framework. The researcher begins by identifying some key concepts and features which they will research about. This gives a foundation for the research. A researcher must be theoretically sensitive so that a theory can be conceptualized and formulated as it emerges from the data being collected. Caution must be taken so as to not limit oneself to specific aspects of a theory; this will make a researcher blind towards other concepts and aspects of the theory. The main question in this method of sampling is this: what group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oil Sampling
Oil analysis (OA) is the laboratory analysis of a lubricant's properties, suspended contaminants, and wear debris. ''OA'' is performed during routine predictive maintenance to provide meaningful and accurate information on lubricant and machine condition. By tracking oil analysis sample results over the life of a particular machine, trends can be established which can help eliminate costly repairs. The study of wear in machinery is called tribology. Tribologists often perform or interpret oil analysis data. OA can be divided into three categories: # analysis of oil properties including those of the base oil and its additives, # analysis of contaminants, # analysis of wear debris from machinery, Oil sampling Oil sampling is a procedure for collecting a volume of fluid from lubricated or hydraulic machinery for the purpose of oil analysis. Much like collecting forensic evidence at a crime scene, when collecting an oil sample, it is important to ensure that procedures are used to mini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Free Sample
A product sample is a sample of a consumer product that is given to the consumer free of cost so that they may try a product before committing to a purchase. Free samples A free sample or "freebie" is a portion of food or other product (for example beauty products) given to consumers in shopping malls, supermarkets, retail stores, or through other channels (such as via the Internet). Sometimes samples of non-perishable items are included in direct marketing mailings. The purpose of a free sample is to acquaint the consumer with a new product, and is similar to the concept of a test drive, in that a customer is able to try out a product before purchasing it. Although an expensive method of targeting customers, conversions to sales can be as high as 90% making it one of the main marketing strategies for certain markets. With effective sampling, marketers can create brand loyalty and assist in the launch of a product through the word of mouth. Many consumer product companies now o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Food Sampling
Food sampling is a process used to check that a food is safe and that it does not contain harmful contaminants, or that it contains only permitted additives at acceptable levels, or that it contains the right levels of key ingredients and its label declarations are correct, or to know the levels of nutrients present. A food sample is carried out by subjecting the product to physical analysis. Analysis may be undertaken by or on behalf of a manufacturer regarding their own product, or for official food law enforcement or control purposes, or for research or public information. To undertake any analysis, unless the whole amount of food to be considered is very small so that the food can be used for testing in its entirety, it is usually necessary for a portion of it to be taken (e.g. a small quantity from a full production batch, or a portion of what is on sale in a shop) – this process is known as food sampling. In most cases with food to be analysed there are two levels of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sample (material)
In general, a sample is a limited quantity of something which is intended to be similar to and represent a larger amount of that thing(s). The things could be countable objects such as individual items available as units for sale, or an uncountable material. Even though the word "sample" implies a smaller quantity taken from a larger amount, sometimes full biological or mineralogical specimens are called samples if they are taken for analysis, testing, or investigation like other samples. They are also considered samples in the sense that even whole specimens are "samples" of the full population of many individual organisms. The act of obtaining a sample is called "sampling" and can be performed manually by a person or by automatic process. Samples of material can be taken or provided for testing, analysis, investigation, quality control, demonstration, or trial use. Sometimes, sampling may be performed continuously. Aliquot part In science, a representative liquid sample tak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sample (graphics)
In computer graphics, a sample is an intersection of channel and a pixel. The diagram below depicts a 24-bit pixel, consisting of 3 samples for Red, Green, and Blue. In this particular diagram, the Red sample occupies 9 bits, the Green sample occupies 7 bits and the Blue sample occupies 8 bits, totaling 24 bits per pixel. Note that the samples do not have to be equal size and not all samples are mandatory in a pixel. Also, a pixel can consist of more than 3 samples (e.g. 4 samples of the RGBA color space). A sample is related to a subpixel In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device. In most digital display devices, pixels are the sm ... on a physical display. References External links W3C Definitions - Section 3.1RGB pixel formats Computer graphics Digital photography Color space {{compu-graphics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sampling (occupational Hygiene)
Occupational hygiene (United States: industrial hygiene (IH)) is the anticipation, recognition, evaluation, control, and confirmation (ARECC) of protection from hazards at work that may result in injury, illness, or affect the well being of workers. These hazards or stressors are typically divided into the categories biological, chemical, physical, ergonomic and psychosocial. The risk of a health effect from a given stressor is a function of the hazard multiplied by the exposure to the individual or group. For chemicals, the hazard can be understood by the dose response profile most often based on toxicological studies or models. Occupational hygienists work closely with toxicologists (see Toxicology) for understanding chemical hazards, physicists (see Physics) for physical hazards, and physicians and microbiologists for biological hazards (see Microbiology Tropical medicine Infection). Environmental and occupational hygienists are considered experts in exposure science and exp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sampling (medicine)
In medicine, sampling is gathering of matter from the body to aid in the process of a medical diagnosis and/or evaluation of an indication for treatment, further medical tests or other procedures. In this sense, the sample is the gathered matter, and the sampling tool or sampler is the person or material to collect the sample. Sampling is a prerequisite for many medical tests, but generally not for medical history, physical examination and radiologic tests. By sampling technique *Obtaining excretions or materials that leave the body anyway, such as urine, stool, sputum, or vomitus, by direct collection as they exit. A sample of saliva can also be collected from the mouth. Excision (cutting out), a surgical method for the removal of solid or soft tissue samples. *Puncture (also called ''centesis'') followed by aspiration is the main method used for sampling of many types of tissues and body fluids. Examples are thoracocentesis to sample pleural fluid, and amniocentesis to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
