• 제목/요약/키워드: External Influence

검색결과 1,337건 처리시간 0.026초

A Knowledge-Based Fuzzy Post-Adjustment Mechanism:An Application to Stock Market Timing Analysis

  • Lee, Kun-Chang
    • 한국경영과학회지
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    • 제20권1호
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    • pp.159-177
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    • 1995
  • The objective of this paper is to propose a knowledge-based fuzzy post adjustment so that unstructured problems can be solved more realistically by expert systems. Major part of this mechanism forcuses on fuzzily assessing the influence of various external factors and accordingly improving the solutions of unstructured problem being concerned. For this purpose, three kinds of knowledge are used : user knowledge, expert knowledge, and machine knowledge. User knowledge is required for evaluating the external factors as well as operating the expert systems. Machine knowledge is automatically derived from historical instances of a target problem domain by using machine learning techniques, and used as a major knowledge source for inference. Expert knowledge is incorporate dinto fuzzy membership functions for external factors which seem to significantly affect the target problems. We applied this mechanism to a prototyoe expert system whose major objective is to provide expert guidance for stock market timing such as sell, buty, or wait. Experiments showed that our proposed mechanism can improve the solution quality of expert systems operating in turbulent decision-making environments.

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Buckling assessment of dented truncated cones under external pressure

  • Ghazijahani, Tohid Ghanbari;Showkati, Hossein;Jiao, Hui
    • Advances in Computational Design
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    • 제1권4호
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    • pp.345-356
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    • 2016
  • Notwithstanding a considerable body of references in the literature on the buckling response of conical shell structures, it seems imperative to provide further insight on the buckling response of locally imperfect steel cones. This paper contains different simulations including non-linear FE analysis and discusses the influence of dent imperfection on the buckling load of these structures subject to external pressure. Data of the present work are evaluated against available experimental results, codes and recommendations and the effect of the local damages is exhaustively set forth. It is also found that the employed FE program can reliably predict the structural response of locally damaged conical shells.

Analysis of ITO on Polymer Substrate by External Bending Force

  • Han, Jin-Woo;Kim, Young-Hwan;Kim, Jong-Hwan;Hwang, Jeoung-Yeon;Seo, Dae-Shik
    • Transactions on Electrical and Electronic Materials
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    • 제6권4호
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    • pp.149-153
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    • 2005
  • In this paper, we investigated the island density-dependent stress distribution of indium-tin-oxide (ITO) film on polycarbonate substrate by external bending force. We used e-beam and RF­sputter for SiON, ITO sputtering. It was found that there are influence of island density on the substrate and decreasing crack density as goes to the minimum density. From the result that crack density was increasing at maximum island density, it is evident that more stress is imposed on same island position as island density.

외부부하가 $I^2L-Inverter$의 기능에 미치는 영향 (The Influence of the External Loads on the $I^2L-Inverter$ Function)

  • 이규영;황호정
    • 대한전자공학회논문지
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    • 제22권2호
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    • pp.75-81
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    • 1985
  • 저전류 범위에서 l2L은 연결되는 소자의 input capacitance, resistance 및 그 소자동작에 필요한 전류들에 의해 출력단의 신호가 손상을 입게 되어 logic기능이 방해를 받게 되며 그로 인한 회로의 불확실성이 증가될 수 있다. 본 논문은 이와같은 외부부하와 연결된 I2L-inverter의 기능에 관한 해석을 다루고 rise time과 fall time의 변화에 관한 simulation 및 실험을 통한 측정결과를 비교 분석하였다.

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외부자계가 Bi-2223테이프의 통전손실에 미치는 영향 (The Influence of External Magnetic Field on Transport Loss in a Bi-2223 tape)

  • 김창완;한형주;류경우;최병주
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 2001년도 학술대회 논문집
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    • pp.169-171
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    • 2001
  • The transport loss of a Bi-2223 tape exposed to external magnetic field was investigated. The results show that the transport loss is independent on voltage lead arrangements in case the magnetization loss is compensated. An serious increase of the transport loss due to external magnetic fields is observed. The loss is described well by dynamic resistance loss in relatively high fields, but another mechanism than the dynamic resistance must be responsible for the increase of the loss in low fields. The transport loss is also dependent strongly on the orientation of the applied field.

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가늘고 긴 소형로켓의 비행특성에 영향을 주는 외력에 기인한 임계하중에 관한 연구 (A study on critical load due to external force influencing on flight characteristics of a small slender body rocket.)

  • 고태식;나선화
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2007년도 제29회 추계학술대회논문집
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    • pp.393-397
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    • 2007
  • 이 연구의 목적은 추력, 항력, 중량 등의 외력들에 기인하여 가늘고 긴 동체의 소형로켓의 비행궤도에 영향을 줄 수 있는 임계하중을 조사하는데 있다. 임계하중은 먼저 Euler 기둥식을 이용하여 구하였고, 검증을 위해 유한 요소법의 수치해석 결과와 비교하였다.

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The Acquisition of External Sandhi in a Second Language: Production of Obstruent Nasalization by Chinese Learners of Korean

  • Han, Jeong-Im
    • 말소리와 음성과학
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    • 제3권1호
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    • pp.77-83
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    • 2011
  • The present study reports the results of an acoustic study of nasal assimilation at word boundaries in Chinese-Korean interlanguage. Twelve Chinese learners of Korean and four Korean native speakers recorded obstruent#nasal sequences in noun compounds and verb phrases, and their different production patterns were examined in detail. While nasalization of the word-final obstruents occurred only in 11.7% of the obstruent#nasal sequences for the Chinese learners, the Korean native speakers showed complete nasalization of those sequences. However, there was small, but consistent effect of learning on the production of external sandhi in L2, because there were shown to be differences in the rate of nasalization between the two proficiency groups of Chinese participants. On average, the intermediate level learners nasalized the target stops at the rate of 16%, and the beginning level learners showed the 7% nasalization rate. In addition, it was found that the context difference such as noun compounds versus verb phrases does not influence the nasalization pattern across word boundaries.

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Crack-bridging force transfer of composite strengthening: a dynamic point of view

  • Ovigne, P.A.;Massenzio, M.;Jacquelin, E.;Hamelin, P.
    • Steel and Composite Structures
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    • 제3권1호
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    • pp.33-46
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    • 2003
  • This study focuses on the influence of a composite external strengthening on the natural frequencies of a steel beam with open cracks. In a first step, the leading parameters associated with the effect of the composite strengthening are experimentally identified. An analytical model is developed in order to quantify the importance of the force transfer within the resin interface. In a second step, the analytical model of a cracked beam with composite external strengthening is compared to experiments.

생체 리듬과 음식 섭취 (Biological Rhythms and Food Intake)

  • 이영호
    • 수면정신생리
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    • 제5권1호
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    • pp.34-44
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    • 1998
  • Living organisms are influenced by many external rhythms and they have adapted their physiology to periodically changing conditions. These adaptive strategies are controlled by endogenous innate programs of behavior and physiology which are determined by external signals ("Zeitgeber"). There are many biological rhythms, each with its own characteristic functional adaptation. Among them, the presence of endogenous time control of feeding and drinking becomes obvious. There are increasing evidences that the control of food intake, food selection, and drinking are regulated by the endogenous rhythms including a circadian rhythm. However, there have been many restrictions in understanding the endogenous control of food intake itself and its mechanism. To broaden our know ledges of the endogenous time control of feeding and drinking, the author reviwed the characteristics of the endogenous timing for food intake, the influence of circadian pacemakers and food-entrainable oscillators, the interaction between the circadian control and the external and internal conditions in the control of food intake, the conseqences of feeding, the circadian control of food selection, and the biological cycles in energy balance.

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CONE CALORIMETER STUDIES OF WOOD SPECIES

  • Grexa, Ondrej;Horvathova, Elena;Osvald, Anton
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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    • pp.77-84
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    • 1997
  • Cone calorimeter measurements can be used for the calculation of effective material properties, which can be used as input parameters in modeling of fire. Main parameter measured in Cone calorimeter is heat release rate. Some other parameters as time to ignition, effective heat of combustion, mass loss rate or total heat released is also measured in Cone calorimeter. Total heat released is important from the point of view of total energy available in material in Fire situation. Cone calorimeter. measurements were done on several wood species (oak, beech, spruce, poplar). Measurements were provided at external irradiances 30, 50 and 65 ㎾/$m_2$ in horizontal orientation. Heat release rate data were evaluated and compared as a function of external irradiance for various species of wood. furthermore the influence of external irradiance on effective heat of combustion and total heat release was also evaluated for the period of flame combustion.

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