• Title/Summary/Keyword: Functional relation

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T-S Fuzzy Modeling of Synchronous Generator in a Power System (전력계통 동기발전기의 T-S Fuzzy 모델링)

  • Lee, Hee-Jin;Baek, Seung-Mook;Park, Jung-Wook
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.9
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    • pp.1642-1651
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    • 2008
  • The dynamic behavior of power systems is affected by the interactions between linear and nonlinear components. To analyze those complicated power systems, the linear approaches have been widely used so far. Especially, a synchronous generator has been designed by using linear models and traditional techniques. However, due to its wide operating range, complex dynamics, transient performances, and its nonlinearities, it cannot be accurately modeled as linear methods based on small-signal analysis. This paper describes an application of the Takaki-Sugeno (T-S) fuzzy method to model the synchronous generator in a single-machine infinite bus (SMIB) system. The T-S fuzzy model can provide a highly nonlinear functional relation with a comparatively small number of fuzzy rules. The simulation results show that the proposed T-S fuzzy modeling captures all dynamic characteristics for the synchronous generator, which are exactly same as those by the conventional modeling method.

Conceptual Extraction of Compound Korean Keywords

  • Lee, Samuel Sangkon
    • Journal of Information Processing Systems
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    • v.16 no.2
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    • pp.447-459
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    • 2020
  • After reading a document, people construct a concept about the information they consumed and merge multiple words to set up keywords that represent the material. With that in mind, this study suggests a smarter and more efficient keyword extraction method wherein scholarly journals are used as the basis for the establishment of production rules based on a concept information of words appearing in a document in a way in which author-provided keywords are functional although they do not appear in the body of the document. This study presents a new way to determine the importance of each keyword, excluding non-relevant keywords. To identify the validity of extracted keywords, titles and abstracts of journals about natural language and auditory language were collected for analysis. The comparison of author-provided keywords with the keyword results of the developed system showed that the developed system was highly useful, with an accuracy rate as good as up to 96%.

A Study on the Automation of Deburring Process Using Vision Sensor (비젼 센서를 이용한 디버링 공정의 자동화에 관한 연구)

  • 신상운;갈축석;강근택;안두성
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.553-558
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    • 1994
  • In this paper, we present a new approach for the automation of deburring process. An algorithm for teaching skills of a human expert to a robot manipulator is developed. This approach makes use of TSK fuzzy model that can express a highly nonlinear functional relation with small number of rules. Burr features such as height, width, area, cutting area are extracted from image processing by use of the vision system. Cutting depth, repeative number and normal cutting force are chosen as control signals representing actions of the human expert. It is verified that our processed fuzzy model can accurately express the skills of human experts for the deburring process.

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Effective thermal conductivity of the phase change material with metal scrap (금속스크랩이 혼합된 상변화물질의 유효열전도율)

  • 김시범;노승탁
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.10 no.6
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    • pp.923-928
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    • 1986
  • A set of measurements has been made for the thermal conductivity of the pure paraffin in liquid and solid phases and for the effective thermal conductivity of the paraffin with metal scrap with the aid of the heat flux meter. Ther thermopile-type heat flux meter has been designed by steady state method and the functional relation between the temperature difference of both sides and heat flux has been obtained. The measured values of thermal conductivity are compared with the existing data for the pure paraffin and with the predicated values from the suggested model in which only one empirical constant is contained. The comparison within ten percent of the volume fraction of the metal scrap in the paraffin is satisfactory.

An Empirical Study on Faults Prediction for Large Scale Telecommunication Software (대규모 통신 소프트웨어의 결함 수 예측에 관한 사례 연구)

  • Park, Young-Sik;Yoon, Byeong-Nam;Lim, Jae-Hak
    • Journal of Korean Society for Quality Management
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    • v.27 no.2
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    • pp.263-276
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    • 1999
  • In this paper, we consider the change request data collected from the system test of a large-scale telecommunication software and analyze the types and causes of failures. And we develop statistical models that incorporate a functional relation between the faults and some software metrics. To this end, we consider three possible regression models including a stepwise regression model and two nonlinear models. Three developed models are evaluated with respect to the predictive quality. We also discuss the advantage of proposed models and the application of our model to a new project.

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A Study on the Mechanism of Arm Surface Changes for the development of Sleeve Drafting Standard (소매설계기준 개발을 위한 상지체표변화구조에 관한 연구)

  • 최해주
    • Journal of the Korean Society of Clothing and Textiles
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    • v.20 no.5
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    • pp.852-859
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    • 1996
  • The factors and mechanism of arm surface changes were analyzed by regression analysis for the relationship between changes in arm joint angle and arm surface changes, according to the direction of upper extremity motion. Body surface change patterns among subjects were tested also. Experiments were carried out on 3 female subjects of different body types to examine 26 motions in 4 directions for 4 upper extremity parts. The major conclusions of the study are as follows: 1. The expansion or contraction of arm surface length depends on the direction of upper extremity motion. 2. Arm surface length changes by linear expansion or contraction according to the joint angle of the direction of motion. The mechanism of arm surface changes is represented by a linear relation between arm surface changes and the (actors of the direction of upper extremity motion and arm joint angle. 3. Arm surface length shows the same pattern of body surface changes regardless of body type. A quantitative model of body surface changes at upper extremity should be developed for functional sleeve design.

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Q-methodological Study on policy reception of public & health campaign (공중건강캠페인 정책 인지도에 관한 Q방법론적 연구 -의료경영학과 대학생들을 중심으로-)

  • Lee, Jei-Young;Choi, Eun-Mi
    • Korea Journal of Hospital Management
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    • v.15 no.4
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    • pp.100-124
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    • 2010
  • This work was researched by practical method in a subjectivity study accessible in-depth, in sloughing off old habit of functional quantity analysis about Reception Type on policy reception of public & health campaign. The perception pattern come out in this study were divided into four types in Q-methodology. The result is as follows ; it is that divided'1[(N=16): Policy Improvement Type], 2[(N=7) : Public-relation Utility Type], 3[(N=19): Financial-continuance Type], 4[(N=11) : Healthy-prevention Orientation Type]'. Like this, it found that is very different type all over. Hereafter, this study is to ascertain acceptance behavior about Reception Type on policy reception of public & health campaign ; to offer a developmental suggestion about it.

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Stabilization of photosynthetic machinery against low-temperature photoinhibition by fatty acid unsaturation of membrane lipids in plants

  • Moon, Byoung-Yong
    • Proceedings of the Botanical Society of Korea Conference
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    • 1999.08a
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    • pp.68-82
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    • 1999
  • CHilling tolereance of plants are closely correlated with the degree of fatty acid unsaturation of membrane lipids. We studied the effects of low-temperature photoinhibition on the photochemical efficiency of photosystem II in terms of fatty acid unsaturation of thylakoid membranes lipids isolated from chilling -sensitive plants and chilling -resistant ones. To directly test the chilling tolerance of photosynthetic machinery in relation to membrane lipids, we further compared wild type tobacco plants with that of transgenic tobacco plants, in which the sensitivity to chilling had been enhanced by genetic modification of fatty acid unsaturation of chloroplast membrane lipids. The transgenic tobacco plants were found to contain reduced levels of unsaturated membrane fatty acids after being transformed with cDNA for glycerol-3-phophate acyltransferase from squash. The functional integrity of photosystem II during and recovery of photosynthesis from low-temperature photoinhibition will be discussed in connection with the degree of fatty acid unsaturation of chlorophast membranes lipids.

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The Human Brain and Information Science: Lessons from Popular Neuroscience

  • Sturges, Paul
    • International Journal of Knowledge Content Development & Technology
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    • v.3 no.1
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    • pp.19-29
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    • 2013
  • Insights from the recent wealth of popular books on neuroscience are offered to suggest a strengthening of theory in information science. Information theory has traditionally neglected the human dimension in favour of 'scientific' theory often derived from the Shannon-Weaver model. Neuroscientists argue in excitingly fresh ways from the evidence of case studies, non-intrusive experimentation and the measurements that can be obtained from technologies that include electroencephalography, positron emission tomography (PET), functional magnetic resonance imaging (fMRI), and magnetoencephalography (MEG). The way in which the findings of neuroscience intersect with ideas such as those of Kahneman on fast and slow thinking and Csikszentmihalyi on flow, is tentatively explored as lines of connection with information science. It is argued that the beginnings of a theoretical underpinning for current web-based information searching in relation to established information retrieval methods can be drawn from this.

Robust Design of Structural and Mechanical Systems using Concept of Allowable Load Set (허용하중집합 개념을 이용한 기계/구조 시스템의 강건 설계)

  • Kwak, Byung-Man
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.333-338
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    • 2007
  • The concept of "Allowable Load Set (ALS)" introduced by the author allows an easy understanding of load and strength characteristics of a structure in relation to its integrity under uncertainties. Two criteria of safety are introduced: A relative safety index denotes the distance to the boundary of the ALS and a normalized safety index is a distance in terms of functional value. They have been utilized in several examples, including multi-body mechanical systems such as a biomechanical system. Both formulations amount to robust designs in the sense that designs most insensitive to uncertainties are obtained in the context of newly defined safety indices, without using any input probability information.

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