805,424 research outputs found

    A study of the use of abstract types for the representation of engineering units in integration and test applications

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    Physical quantities using various units of measurement can be well represented in Ada by the use of abstract types. Computation involving these quantities (electric potential, mass, volume) can also automatically invoke the computation and checking of some of the implicitly associable attributes of measurements. Quantities can be held internally in SI units, transparently to the user, with automatic conversion. Through dimensional analysis, the type of the derived quantity resulting from a computation is known, thereby allowing dynamic checks of the equations used. The impact of the possible implementation of these techniques in integration and test applications is discussed. The overhead of computing and transporting measurement attributes is weighed against the advantages gained by their use. The construction of a run time interpreter using physical quantities in equations can be aided by the dynamic equation checks provided by dimensional analysis. The effects of high levels of abstraction on the generation and maintenance of software used in integration and test applications are also discussed

    Conceptual design and applications of HgCdTe infrared photodiodes for heterodyne systems

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    The significance of HgCdTe photodiodes are discussed relative to their existance in heterodyne detection systems operating in the 9 to 11 micrometer CO2 laser wavelength region. Their successful fabrication as well as the physical properties of the materials are described. The implementation of controlled industrial processes are reported with emphasis on the yield of predictable and repeatable detector characteristics to the discriminating systems, demands for high cutoff frequencies, quantum efficiency, and reliability. The most salient production steps and diode characteristics are presented. Measured results from production units are also given

    Adding HL7 version 3 data types to PostgreSQL

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    The HL7 standard is widely used to exchange medical information electronically. As a part of the standard, HL7 defines scalar communication data types like physical quantity, point in time and concept descriptor but also complex types such as interval types, collection types and probabilistic types. Typical HL7 applications will store their communications in a database, resulting in a translation from HL7 concepts and types into database types. Since the data types were not designed to be implemented in a relational database server, this transition is cumbersome and fraught with programmer error. The purpose of this paper is two fold. First we analyze the HL7 version 3 data type definitions and define a number of conditions that must be met, for the data type to be suitable for implementation in a relational database. As a result of this analysis we describe a number of possible improvements in the HL7 specification. Second we describe an implementation in the PostgreSQL database server and show that the database server can effectively execute scientific calculations with units of measure, supports a large number of operations on time points and intervals, and can perform operations that are akin to a medical terminology server. Experiments on synthetic data show that the user defined types perform better than an implementation that uses only standard data types from the database server.Comment: 12 pages, 9 figures, 6 table

    EMBODIMENT IN SECOND LANGUAGE LEARNING AND TEACHING

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    This paper aims to elaborate the implementation of Embodiment as one of the concept of Cognitive Linguistics in second language learning and teaching. Cognitive Linguistics is simply pointed that language is all about meaning. It views the learner as a thinking being and an active processor of information. However, it is interesting as we found that mind and body are not separate entities. Involved in understanding what people say to us and what we read, Embodiment relates meanings directly to our physical experience; it emphasizes on the way cognition is shaped by the body and its sensorimotor interaction with the world. Furthermore, this paper is trying to show how the theoretical assumptions, basic units, and constructs used in Cognitive Linguistics offer a better understanding of the true nature of language and grammar, and how Embodiment may improve current second language teaching and learning methods

    User Manual for Physical Scalars and Plotting Tools in Scala

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    An open-source scalar package and associated software tools have been developed in the Scala programming language, including plotting tools based on the free GRACE plotting package. The scalar package represents physical scalars and can help to prevent errors involving physical units in engineering and scientific computation. The scalar package includes a complete implementation of the standard SI metric system of units and many common non-metric units. The design also allows users to easily de ne a specialized or reduced set of physical units for any particular application or domain. The scalar package can be used in two different modes: one mode provides unit compatibility checking but is slower, and the other mode bypasses the compatibility checks but is much faster and still prevents the most common type of unit error. Switching between the two modes requires no changes in the user's code, making it convenient and usable with no significant performance penalty for even the most computationally intensive applications

    Metrological characterization of the pulsed Rb clock with optical detection

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    We report on the implementation and the metrological characterization of a vapor-cell Rb frequency standard working in pulsed regime. The three main parts that compose the clock, physics package, optics and electronics, are described in detail in the paper. The prototype is designed and optimized to detect the clock transition in the optical domain. Specifically, the reference atomic transition, excited with a Ramsey scheme, is detected by observing the interference pattern on a laser absorption signal. \ The metrological analysis includes the observation and characterization of the clock signal and the measurement of frequency stability and drift. In terms of Allan deviation, the measured frequency stability results as low as 1.7×10−13 τ−1/21.7\times 10^{-13} \ \tau^{-1/2}, τ\tau being the averaging time, and reaches the value of few units of 10−1510^{-15} for τ=104\tau=10^{4} s, an unprecedent achievement for a vapor cell clock. We discuss in the paper the physical effects leading to this result with particular care to laser and microwave noises transferred to the clock signal. The frequency drift, probably related to the temperature, stays below 10−1410^{-14} per day, and no evidence of flicker floor is observed. \ We also mention some possible improvements that in principle would lead to a clock stability below the 10−1310^{-13} level at 1 s and to a drift of few units of 10−1510^{-15} per day

    STRATEGI PENINGKATAN MUTU STANDAR PROSES PEMBELAJARAN MATEMATIKA

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    Process Standards are national education standards relating to the implementation of learning in educational units to achieve graduate competency, applicable to primary and secondary education levels in the formal school, both in the package system and in the semester credit system. Furthermore, through articles 19 to 22 concerning Educational Process Standards that the learning process in educational units is carried out interactively, inspiring, fun, challenging, motivating students to participate actively, and providing sufficient space for initiative, creativity and independence according to talents, interests and the physical and psychological development of students, the existence of exemplary educators, the existence of effective and efficient planning, implementation, and supervision in the assessment of the learning processKeywords:Quality Strategy, Process Standards, Math Teache
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