• 제목/요약/키워드: physical uncertainty

검색결과 263건 처리시간 0.022초

Asset Localization in Wireless Sensor Networks

  • Jo, Jung-Hee;Kim, Kwang-Soo;Kim, Sun-Joong
    • 대한원격탐사학회지
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    • 제23권5호
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    • pp.465-471
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    • 2007
  • Many hospitals have been considering new technology such as wireless sensor network(WSN). The technology can be used to track the location of medical devices needed for inspections or repairs, and it can also be used to detect of a theft of an asset. In an asset-tracking system using WSN, acquiring the location of moving sensor nodes inherently introduces uncertainty in location determination. In fact, the sensor nodes attached to an asset are prone to failure from lack of energy or from physical destruction. Therefore, even if the asset is located within the predetermined area, the asset-tracking application could "misunderstand" that an asset has escaped from the area. This paper classifies the causes of such unexpected situations into the following five cases: 1) an asset has actually escaped from a predetermined area; 2) a sensor node was broken; 3) the battery for the sensor node was totally discharged; 4) an asset went into a shadow area; 5) a sensor node was stolen. We implemented and installed our asset-tracking system in a hospital and continuously monitored the status of assets such as ventilators, syringe pumps, wheel chairs and IV poles. Based on this real experience, we suggest how to differentiate each case of location uncertainty and propose possible solutions to prevent them.

The Uncertainties in Contemporary Art

  • Pan Bo
    • International Journal of Advanced Culture Technology
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    • 제11권2호
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    • pp.170-177
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    • 2023
  • In quantum mechanics, uncertainty refers to the uncertainty of a measurement physical quantity, because some mechanical quantity can only be in its eigenstate under certain conditions, and the values shown are discrete.The exact value can only be obtained by measuring it in the eigenstate of this mechanical quantity.Uncertainty is like a double-edged sword, which has both advantages and disadvantages in art itself and in the process of artistic creation. In this study, it is divided into three main parts. First, the existence of uncertainties in contemporary art is sorted out in two broad parts, the definition of the uncertainties in art and the specific expression in contemporary art, respectively, with examples from four aspects of psychological impact, accidental presentation effect, expression form and connection with the viewer. The purpose is to understand how uncertainties are expressed in the process of artistic creation. Second, the role of the uncertainties in artistic creation is analyzed through examples, and then it is proposed that artists should use uncertainties to serve art with a scientific and rational attitude. Thirdly, the application of uncertainties in my creative practice and their influences on my painting creation. In summary, every artistic creator should take art seriously and sincerely. The relationship among the creative subject, society and life is an eternal and continuous interaction, and art is a carrier of reflection. For the problems brought by uncertainties in artistic creation, from choosing new certainty by thinking to the emergence of uncertainties, such a cycle is the process of art sublimating from life and being closely related to life.

수명의 불확실성을 반영한 추계학적 장비 대체시기 결정모형 (A Stochastic Optimization Model for Equipment Replacement Considering Life Uncertainty)

  • 박종인;김승권
    • 한국국방경영분석학회지
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    • 제29권2호
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    • pp.100-110
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    • 2003
  • Equipment replacement policy may not be defined with certainty, because physical states of any technological system may not be determined with foresight. This paper presents Markov Decision Process(MDP) model for army equipment which is subject to the uncertainty of deterioration and ultimately to failure. The components of the MDP model is defined as follows: ⅰ) state is identified as the age of the equipment, ⅱ) actions are classified as 'keep' and 'replace', ⅲ) cost is defined as the expected cost per unit time associated with 'keep' and 'replace' actions, ⅳ) transition probability is derived from Weibull distribution. Using the MDP model, we can determine the optimal replacement policy for an army equipment replacement problem.

불연속면의 영향을 고려한 암반동굴의 확률유한요소해석 (Stochastic Finite Element Analysis for Rock Caverns Considering the Effect of Discontinuities)

  • 최규섭;황신일;이경진
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1996년도 가을 학술발표회 논문집
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    • pp.95-102
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    • 1996
  • In this study, a stochastic finite element model is proposed with a view to consider the uncertainty of physical properties of discontinuous rock mass in the analysis of structural behavior on underground caverns. In so doing, the LHS(Latin Hypercube sampling) technique has been applied to make up weak points of the Crude Monte Carlo technique. Concerning the effect of discontinuities, a joint finite element model is used that is known to be superior in explaining faults, cleavage, things of that nature. To reflect the uncertainty of material properties, the variables such as the the elastic modulus, the poisson's ratio, the joint shear stiffness, and the joint normal stiffness have been used, all of which can be applicable through normal distribution, log-normal distribution, and rectangulary uniform distribution. The validity of the newly developed computer program has been confirmed in terms of verification examples. And, the applicability of the program has been tested in terms of the analysis of the circular cavern in discontinuous rock mass.

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2000년대 패션에 나타난 추상적 문양의 조형적 특성 (Formative Characteristics of Abstract Pattern in 2000's Fashion)

  • 유현정
    • 한국의상디자인학회지
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    • 제11권3호
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    • pp.17-25
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    • 2009
  • The purpose of this study is to help understanding of abstract patterns and to play a guideline's role in the development of designs and the prediction of trends for present and future fashion designers and textile designers. The summary of this study's results is like followings. Formative characteristics of abstract pattern in 2000's fashion are Impromptu, Anti-mechanism, Superimposing, Disorder. First, Impromptu is rebounce against uniformity, mechanism, man-created beauty Second, Anti-mechanism represents unfinishing, unbalance, inaccuracy and relates with each traditional of nation or ethnic group. Third, Presupposing transparency Superimposing offsets each patterns. So Their images are ambiguity, ununiformity, unequality, incompletion, uncertainty and so on. Fourth, Disorder breaks and ignores physical balance, rule, order and so on. These images represent uncertainty, freedom, naturality. From this result, I can interpret that these images are representing of humanism reacting about uniformity, mechanism, man-created beauty, completeness of modernism since the Industrial Revolution.

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Robust Controller Implementation in DCS for a MIMO Paper-making Process with long transport delays

  • Kang, Ki-Ho;Lee, Bong-Kuk;Lim, Kye-Young
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2002년도 ICCAS
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    • pp.70.3-70
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    • 2002
  • This paper presents a procedure of implementing a robust controller for a paper-making plant in DCSs. A paper-making process generally has triple problems to automatically tune its output qualities . Long transport delays which are not able to be simply linearized. The transfer matrix of the process is not square. And every plant model has some uncertainty in low and middle frequency region. To tackle these problems, a multi-input / multi-output (MIMO) plant model having some uncertainty was derived by considering some physical and mechanical principles of the process. Then a MIMO robust-controller is designed and implemented in a real DCS as function block type. Some special co...

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양방향 반사율 분포함수 측정시스템 (Measurement System of Bidirectional Reflectance-distribution Function)

  • 황지수
    • 한국광학회지
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    • 제21권2호
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    • pp.46-52
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    • 2010
  • 본 논문에서는 양방향 반사율 분포함수의 이론과 제작된 측정시스템 및 측정불확도의 평가방법을 소개한다. (380~1500) nm의 분광 양방향 반사율 분포함수를 $(-75{\sim}75)^{\circ}$의 각도 범위에서 측정할 수 있는 측정시스템을 제작하였고, 상관관계가 있는 불확도 성분과 상관관계가 없는 불확도 성분으로 나누어 측정불확도를 평가하였다. 평가 결과, 제작된 양방향 반사율 분포함수 측정시스템의 상대확장불확도는 3% (k=2) 이하로 평가되었다.

이원계 Co-C 공정계 온도 고정점의 특성 (Phase transition features of binary Co-C eutectic temperature fixed-point)

  • 김용규;양인석;감기술
    • 센서학회지
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    • 제14권6호
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    • pp.381-386
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    • 2005
  • A Co-C eutectic cell for thermocouple calibration was manufactured and tested to investigate its phase transition characteristics using Type B thermocouples. It was observed that the freezing plateaus were flatter than those of melting, but the melting points were closer to the true transition temperature than the freezing points. The expanded uncertainty of melting temperature was calculated not to exceed $0.2^{\circ}C$ (k = 2). Based on the observed results, the melting process is recommended for the calibration of thermocouples.

PSA: A Photon Search Algorithm

  • Liu, Yongli;Li, Renjie
    • Journal of Information Processing Systems
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    • 제16권2호
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    • pp.478-493
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    • 2020
  • We designed a new meta-heuristic algorithm named Photon Search Algorithm (PSA) in this paper, which is motivated by photon properties in the field of physics. The physical knowledge involved in this paper includes three main concepts: Principle of Constancy of Light Velocity, Uncertainty Principle and Pauli Exclusion Principle. Based on these physical knowledges, we developed mathematical formulations and models of the proposed algorithm. Moreover, in order to confirm the convergence capability of the algorithm proposed, we compared it with 7 unimodal benchmark functions and 23 multimodal benchmark functions. Experimental results indicate that PSA has better global convergence and higher searching efficiency. Although the performance of the algorithm in solving the optimal solution of certain functions is slightly inferior to that of the existing heuristic algorithm, it is better than the existing algorithm in solving most functions. On balance, PSA has relatively better convergence performance than the existing metaheuristic algorithms.

산업용 저항 온도계의 저온 자동 비교 교정 시스템 개발 (Development of the automatic calibration system for industrial resistance thermometers at low temperatures)

  • 양인석;송창호;강기훈;김용규
    • 센서학회지
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    • 제17권6호
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    • pp.429-436
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    • 2008
  • A system is designed and fabricated for the automatic low temperature calibration by comparison of industrial resistance thermometers. The cryostat is suitable for the calibration of four capsule type thermometers and four long stem thermometers. By the automatic temperature control of the cryostat, we could calibrate thermometers from $-200^{\circ}C$ to $0^{\circ}C$ for ${\sim}15$ hours by one fill of liquid nitrogen in the test run of the system. The uncertainty of the calibration for industrial platinum resistance thermometers using the automatic system is about 30mK with a 95.% confidence interval.