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A Study of Statistical Tools Application - Evaluation of Process Capability - (통계적기법(統計的技法) 활용(活用)에 관(關)한 연구(硏究) - 공정능력평가(工程能力評價)를 중심(中心)으로 -)

  • Seong, Won-Yong;Jung, Soo-Il
    • Journal of the Korea Safety Management & Science
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    • v.10 no.2
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    • pp.195-203
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    • 2008
  • The purpose of this study is to develop a guideline of process capability evaluation and to apply this guideline improving the quality of products, especially in the small and medium enterprises. In this study we deal in the concept of process capability evaluation, the calculation of process capability index, and the application of a case study. Man must compare the state of process with the standards in evaluating of the process capability. Control chart can be used as a yardstick for judgement for the long term period and the distribution shape of histogram for the short term period. Man should regard to the significant figure by the calculation of process capability index.

Opportunistic Scheduling with QoS Constraints for Multiclass Services HSUPA System

  • Liao, Dan;Li, Lemin
    • ETRI Journal
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    • v.29 no.2
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    • pp.201-211
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    • 2007
  • This paper focuses on the scheduling problem with the objective of maximizing system throughput, while guaranteeing long-term quality of service (QoS) constraints for non-realtime data users and short-term QoS constraints for realtime multimedia users in multiclass service high-speed uplink packet access (HSUPA) systems. After studying the feasible rate region for multiclass service HSUPA systems, we formulate this scheduling problem and propose a multi-constraints HSUPA opportunistic scheduling (MHOS) algorithm to solve this problem. The MHOS algorithm selects the optimal subset of users for transmission at each time slot to maximize system throughput, while guaranteeing the different constraints. The selection is made according to channel condition, feasible rate region, and user weights, which are adjusted by stochastic approximation algorithms to guarantee the different QoS constraints at different time scales. Simulation results show that the proposed MHOS algorithm guarantees QoS constraints, and achieves high system throughput.

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Analysis of the thermal performances of air-earth direct heat exchanger (공기 지중간 직접열교환시스템의 열성능 해석)

  • Kim, W.K.;An, J.S.;Choi, Y.D.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.9 no.2
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    • pp.112-121
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    • 1997
  • This study is focused on the development and selection of optimal cool tube system to maximize its thermal performance. Cool tube is devised to reduce the heating and cooling load of building by preheating or refreshing of intake air. Finite volume method was adopted to solve the conduction problem between the cool tube and earth. We examine the cool tube system for two operating periods, a short term(12 hours) and a long term(3 months). The results of short term operations reveal that condensation significantly influences and raises the exit air temperature. For long term operations, optimum conditions of cool tube system are obtained with variations of flow-rate, depth, length and diameter of cool tube.

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The Relationship between Organizational Justice and Service Quality, and Moderating Effects of Sex and Tenure (조직공정성과 서비스품질의 관계 및 성, 재직기간의 조절효과)

  • 안관영
    • Journal of Korean Society for Quality Management
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    • v.30 no.3
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    • pp.1-19
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    • 2002
  • Greenberg(1990) suggested that organizational justice research may potentially explain many organizational behavior outcome variables. One example of nontraditional job behavior is service quality, for it is part of the spontaneous and innovative behaviors noted by Katz(1964). The first purpose of this research is to test the effects of organizational justice on service quality, and the second purpose is to test the moderating effects of sex and tenure on the relationships between organizational justice and service quality According to statistical analysis, only interactional justice had an impact on service quality. Also the results of moderating regression analysis showed that short term employees were more sensitive to distributive justice than long term employees. This result means short term employees are more interested In incentive system than long term employees.

Nuclear Reactor Modeling in Load Following Operations for UCN 3 with NARX Neural Network - (NARX 신경회로망을 이용한 부하추종운전시의 울진 3호기 원자로 모델링)

  • Lee, Sang-Kyung;Lee, Un-Chul
    • Proceedings of the KIEE Conference
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    • 2005.05a
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    • pp.21-23
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    • 2005
  • NARX(Nonlinear AutoRegressive with eXogenous input) neural network was used for prediction of nuclear reactor behavior which was influenced by control rods in short-term period and also by xenon and boron in long-term period in load following operations. The developed model was designed to predict reactor power, xenon worth and axial offset with different burnup rates when control rod and boron were adjusted in load following operations. Data of UCN 3 were collected by ONED94 code. The test results presented exhibit the capability of the NARX neural network model to capture the long term and short term dynamics of the reactor core and seems to be utilized as a handy tool for the use of a plant simulation.

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Long Term Prediction of Korean-U.S. Exchange Rate with LS-SVM Models

  • Hwang, Chang-Ha;Park, Hye-Jung
    • Journal of the Korean Data and Information Science Society
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    • v.14 no.4
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    • pp.845-852
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    • 2003
  • Forecasting exchange rate movements is a challenging task since exchange rates impact world economy and determine value of international investments. In particular, Korean-U.S. exchange rate behavior is very important because of strong Korean and U.S. trading relationship. Neural networks models have been used for short-term prediction of exchange rate movements. Least squares support vector machine (LS-SVM) is used widely in real-world regression tasks. This paper describes the use of LS-SVM for short-term and long-term prediction of Korean-U.S. exchange rate.

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Study and Implementation on Compensation of Step Jump Errors and Integrated Filter in the INS/GPS System

  • Hong, Woon-Seon;Choi, Sang-Wook;Park, Heung-Won;Kim, Chen-Jung
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.114.3-114
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    • 2001
  • The pure navigation system using Inertial Navigation Unit(INU) which has very accurate short term stabilities but not long term gives rise to position errors propotional to time. On the contrary, Global Positioning System(GPS) which is bounded its errors to some fixed ranges shows higher accuracy in the long term, and lower accuracy in the short term than that of INS. Recently the integration of these two systems is one of the main topic in the field of navigation system. In this thesis, the implementation of kalman filter on the real time navigation computer and step jump error compensation method is suggested.

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The Effects of Loss Aversion and Construal Level on the Attitude toward Financial Products (투자자의 손실회피 성향과 해석수준이 금융상품 태도에 미치는 영향)

  • Kang, Hyunmo
    • Knowledge Management Research
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    • v.18 no.1
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    • pp.49-65
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    • 2017
  • Financial products entail either gains or losses, and customers' psychological reaction to these gains and losses affect the selection of the financial products. This study explains the financial customers' behavior by introducing consumers' psychological variables such as loss aversion and construal levels. According to the construal level theory, people use more abstract and higher levels of construal to represent objects that are more distant on psychological distance. Based on extant research about loss aversion and construal levels, this study proposes two hypotheses and test the hypotheses. The experimental study examines how loss aversion affects the choice between deposit products and fund products in short-term and long-term investment situations. In the long-term condition the respondents prefer fund products to deposit products, whereas in the short-term condition the respondents have showed the opposite result. Also, the effects of loss aversion on preferences for financial products have interacted with the time horizon of investments. Implications and limitations are discussed to establish more effective marketing strategies based on the results of this study.

Learning Dynamic Changes of User Interests in Personalized News Agent (사용자의 동적인 관심변화를 학습하는 개인화된 뉴스 에이전트)

  • 고경희;오경환
    • Proceedings of the Korean Information Science Society Conference
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    • 2001.10b
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    • pp.82-84
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    • 2001
  • 정보여과 시스템은 사용자의 관심사를 정확하게 알아내야 하고(specialization), 시간에 따른 변화에 적응할 수 있어야 하며(adaptation), 사용자의 잠재적인 관심사를 발견하기 위해 새로운 도메인을 탐험할 수 있어야 한다(exploration). 본 논문에서는 온라인 뉴스 기사를 여과하여 사용자와 관련이 있는 뉴스 기사를 추천하는 뉴스 에이전트를 설계, 구현하고자 한다. Specialization, adaptation의 두 가지 요구사항을 충족시키기 위해 사용자의 관심사를 도메인별로 분리하고 각 도메인은 long-term과 short-term으로 나눈다. Exploration의 요구사항을 충족시키기 위해서는 카테고리 절차(crossover) 연산을 사용한다. 실험 결과, 사용자에 대한 사전 정보가 전혀 없는 상태에도 불구하고 빠른 적응능력을 보였다. long-term과 short-term의 분리는 사용자의 관심사에 급격한 변화가 일어난 후에도 시스템이 빠르게 적응할 수 있음을 보여주었다. 또한 카테고리 교차 연산을 통해 사용자의 새로운 관심사 탐험을 수행해 낼 수 있음을 보여주었다.

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Analysis on the thermal performances of air-earth direct heat exchanger in one year (공기 지중간 직접열교환시스템의 연중 열성능 해석)

  • Kim, W.K.;An, J.S.;Choi, Y.D.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.9 no.4
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    • pp.517-526
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    • 1997
  • This study is focused on the development and selection of the optimal cool tube system to maximize its thermal performance. Cool tube is devised to reduce the heating and cooling load of building by preheating or refreshing of intake air with buried pipes. Finite volume method is adopted to solve the conduction problem between the cool tube and earth. We examine the cool tube system for two operating periods, a short term(12 hours) and a long term(3 months). The results of short term operations reveal that condensation significantly influences and raises the exit air temperature. For long term operations, optimum conditions of cool tube system are obtained with variations of flow-rate, depth, length and diameter of cool tube.

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