• 제목/요약/키워드: Sequence algebra

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병행성 명세를 위한 확장된 Z의 연구 (A Study on Extended Z for the Concurrency Specification)

  • 남성욱;조영석
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2000년도 추계학술발표논문집 (상)
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    • pp.575-578
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    • 2000
  • 소프트웨어 개발 초기 단계에서의 부정확에 기인한 에러들을 줄이기 위한 노력이나 기술이 절실하다. [1][2] 정형 명세 기법은 명세 단계에서 기인하는 에러들을 줄이기 위해 Z 나 VDM 과 같은 정형 표기법(formal notation)에 의해 쓰여지며, 정형성(formality)과 추상화(abstraction)의 제공 등 두 가지 사항에 대한 요구사항을 충족시켜 준다. [3][4] 그러나, Z 표기법의 병행성 표현 능력의 부족으로 병행성을 요구하는 시스템의 명세에서 사용할 수 없거나, Process Algebra의 CSP (Communicating Sequence Processes)등과 같은 다른 정형 언어와 함께 명세해야 하는 단점이 있다. 본 논문은 이를 보완하기 위해 범용 목적의 명세 언어인 기존의 Z 를 확장하여 병행성을 명세 가능하도록 하고자 한다. 이를 위해서 병행 프로세스(concurrent process) 개념을 도입하며, 이를 나타내는 표기를 정의하고 사용한다. 또한, 병행성의 제어를 위해서 프로시듀어 기술부(procedure description)의 도입 및 관련 스키마(schema)들을 정의한다. 아울러, 확장된 Z 로 작성된 명세서를 목적 언어로 자동 변환(translate)하기 위한 변환기(translator)를 Lex 와 Yacc을 이용하여 구현하고, 변환된 목적 언어 파일을 실행하여 확장된 Z 가 모호성을 포함하지 않는지 시뮬레이션을 통해 검증한다.

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이동 통신 시스템에서 조정 계수를 이용한 적응 등화기에 관한 연구 (A Study On The Adaptive Equalizer Of Coefficient Adjustment In Mobile Communication Systems)

  • 전상규;김노환
    • 한국컴퓨터정보학회논문지
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    • 제1권1호
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    • pp.53-64
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    • 1996
  • 이동 통신 시스템에서 DSP 기능을 수행하는 적응필터를 설계하기 위한 방법으로는 최소-제곱조정(Least-squares adjustment) 알고리즘. Fast-Kalman 알고리즘 그리고 적응 격자(adaptive lattice) 알고리즘이 있다. 최소-제곱 조정 알고리즘은 적응 등화의 신호처리를 위해 고속 수렴하고이동 통신 시스템의 다중 경로 페이딩 채널에서 발생되는 심볼간 간섭을 제거하는데 사용된다. 본 논문에서는 기존의 최소-제곱 조정 알고리즘의 계수를 몇 가지 새로운 데이타 순서에 대한 샘플링 된 신호 벡터의 대수학적인 특성을 적절히 조정하여 구하는 방법을 제시하였고 컴퓨터 시물레이션 결과 기존 알고리즘들보다 고속 수렴하고 반복 수행 속도가 개선됨을 확인하였다.

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Duality of Paranormed Spaces of Matrices Defining Linear Operators from 𝑙p into 𝑙q

  • Kamonrat Kamjornkittikoon
    • Kyungpook Mathematical Journal
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    • 제63권2호
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    • pp.235-250
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    • 2023
  • Let 1 ≤ p, q < ∞ be fixed, and let R = [rjk] be an infinite scalar matrix such that 1 ≤ rjk < ∞ and supj,k rjk < ∞. Let 𝓑(𝑙p, 𝑙q) be the set of all bounded linear operator from 𝑙p into 𝑙q. For a fixed Banach algebra 𝐁 with identity, we define a new vector space SRp,q(𝐁) of infinite matrices over 𝐁 and a paranorm G on SRp,q(𝐁) as follows: let $$S^R_{p,q}({\mathbf{B}})=\{A:A^{[R]}{\in}{\mathcal{B}}(l_p,l_q)\}$$ and $G(A)={\parallel}A^{[R]}{\parallel}^{\frac{1}{M}}_{p,q}$, where $A^{[R]}=[{\parallel}a_{jk}{\parallel}^{r_{jk}}]$ and M = max{1, supj,k rjk}. The existance of SRp,q(𝐁) equipped with the paranorm G(·) including its completeness are studied. We also provide characterizations of β -dual of the paranormed space.

인체의 위 조직 시료에서 자기공명영상장치를 이용한 확산계수 측정에 대한 기초 연구 (Ex Vivo MR Diffusion Coefficient Measurement of Human Gastric Tissue)

  • 문치웅;최기승;;;양영일;장희경;은충기
    • 대한의용생체공학회:의공학회지
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    • 제27권5호
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    • pp.203-209
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    • 2006
  • The aim of this study is to investigate the feasibility of ex vivo MR diffusion tensor imaging technique in order to observe the diffusion-contrast characteristics of human gastric tissues. On normal and pathologic gastric tissues, which have been fixed in a polycarbonate plastic tube filled with 10% formalin solution, laboratory made 3D diffusion tensor Turbo FLASH pulse sequence was used to obtain high resolution MR images with voxel size of $0.5{\times}0.5{\times}0.5mm^3\;using\;64{\times}32{\times}32mm^3$ field of view in conjunction with an acquisition matrix of $128{\times}64{\times}64$. Diffusion weighted- gradient pulses were employed with b values of 0 and $600s/mm^2$ in 6 orientations. The sequence was implemented on a clinical 3.0-T MRI scanner(Siemens, Erlangen, Germany) with a home-made quadrature-typed birdcage Tx/Rx rf coil for small specimen. Diffusion tensor values in each pixel were calculated using linear algebra and singular value decomposition(SVD) algorithm. Apparent diffusion coefficient(ADC) and fractional anisotropy(FA) map were also obtained from diffusion tensor data to compare pixel intensities between normal and abnormal gastric tissues. The processing software was developed by authors using Visual C++(Microsoft, WA, U.S.A.) and mathematical/statistical library of GNUwin32(Free Software Foundation). This study shows that 3D diffusion tensor Turbo FLASH sequence is useful to resolve fine micro-structures of gastric tissue and both ADC and FA values in normal gastric tissue are higher than those in abnormal tissue. Authors expect that this study also represents another possibility of gastric carcinoma detection by visualizing diffusion characteristics of proton spins in the gastric tissues.

원자력발전소의 화재사건 확률론적안전성평가 모델 구축에 관한 연구 (A Study on the Constructions of Fire Events Probabilistic Safety Assessment Model for Nuclear Power Plants)

  • 강대일;김길유
    • 한국안전학회지
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    • 제31권5호
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    • pp.187-194
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    • 2016
  • A single fire event within a fire area can cause multiple initiating events considered in internal events probabilistic safety assessment (PSA). For an example, a fire event in turbine building fire area can cause a loss of the main feed-water and loss of off-site power initiating events. This fire initiating event could result in special plant responses beyond the scope of the internal events PSA model. One approach to address a fire initiating event is to develop a specific fire event tree. However, the development of a specific fire event tree is difficult since the number of fire event trees may be several hundreds or more. Thus, internal fire events PSA model has been generally constructed by modifications of the pre-developed internal events PSA model. New accident sequence logics not covered in the internal events PSA model are separately developed to incorporate them into the fire PSA model. Recently, many fire PSA models have fire induced initiating event fault trees not shown in an internal event PSA model. Up to now, there has been no analytical comparative study on the constructions of fire events PSA model using internal events PSA model with and without fault trees of initiating events. In this study, the changing process of internal events PSA model to fire events PSA model is analytically presented and discussed.

남북한 중등학교 수학교육의 통합방안 모색 (A Comparative Study on the Secondary School Mathematics Education of South and North Korea)

  • 우정호;박문환
    • 대한수학교육학회지:수학교육학연구
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    • 제12권1호
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    • pp.49-70
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    • 2002
  • There have recently been increasing exchanges between South and North Korea in many areas of society, involving politics, economics, culture, education. In response to these developments, research activities are more strongly demanded in each of these areas to help prepare for the final unification of the two parts of the nation. In the area of mathematics education, scholars have started to conduct comparative studies of mathematics education in South and North Korea. As a response to the growing demand of the time, in this thesis we compared the secondary mathematics education in South Korea with that in North Korea. To begin with, we examined the background of education, in North Korea, particularly predominant ideological, epistemological and teaching theoretical aspects of education in North Korea. Thereafter, we compared the mathematics curriculum of South Korea with that of North Korea. On the basis of these examinations, we compared the secondary school mathematics textbooks of South and North Korea, and we attempted to suggest a guideline for researches preparing for the unification of the mathematics curriculum of South and North Korea. As a communist society, North Korea awards the socialist ideology the supreme rank and treats all school subjects as instrumental tools that are subordinated to the dominant communist ideology. On the other hand, under the socialist ideology North Korea also emphasizes the achievement of the objective of socialist economic development by expanding the production of material wealth. As such, mathematics in North Korea is seen as a tool subject for training skilled technical hands and fostering science and technology, hence promoting the socialist material production and economic development. Hence, the mathematics education of North Korea adopts a so-called "awakening teaching method," and emphasizes the approaches that combine intuition with logical explanation using materials related with the ideology or actual life. These basic viewpoints of North Korea on mathematics education are different from those of South Korea, which emphasize the problem-solving ability and acquisition of academic mathematical knowledge, and which focus on organizing as well as discovering knowledge of learners' own accord. In comparison of the secondary school mathematics textbooks used in South and North Korea, we looked through external forms, contents, quantity of each area of school mathematics, viewpoints of teaching, and term. We have identified similarities in algebra area and differences in geometry area especially in teaching sequence and approaching method. Many differences are also found in mathematical terms. Especially, it is found that North Korea uses mathematical terms in Hangul more actively than South Korea. We examined the specific topics that are treated in both South and North Korea, "outer-center & inner-center of triangle" and "mathematical induction", and identified such differences more concretely. Through this comparison, it was found that the concrete heterogeneity in the textbooks largely derive from the differences in the basic ideological viewpoints between South and North Korea. On the basis of the above findings, we attempted to make some suggestions for the researches preparing for the unification in the area of secondary mathematics education.

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