• Title/Summary/Keyword: Level- Set theory

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Absolute categories and relative categories (절대범주와 상대범주)

  • Kwon, Kyeong-Won
    • English Language & Literature Teaching
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    • v.8 no.2
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    • pp.131-150
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    • 2003
  • The purpose of this paper is to provide two levels of conceptualization of a category such as an absolute category in semantic level and a relative category in pragmatic level on the basis of Aristotelian category theory and prototype category theory. I do not intend to criticize classical category theory and prototype category theory but to show that these two types of category are applied to the different world. Aristotelian categorization is an absolute category because it is based on the possible world called the meta-world and it has an absolute truth value. The members of an absolute category is presented as a set. There is a clear boundary between members and non-members because they are distinguished by the absolute criteria An absolute category is semantic conceptualization. This absolute category is changed into a relative category when it is applied in the real world. A relative category which corresponds to a prototype category is based on the real world called the object world and it has a relative truth value. Here individuals are categorized by the cognition and perception of human beings. A relative category is pragmatic conceptualization. In conclusion, while classical categories which are called absolute categories represent sentence meaning, prototype categories which are called relative categories represent utterance meaning.

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The level set-based topology optimization for three-dimensional functionally graded plate using thin-plate spline

  • Banh, Thanh T.;Luu, Nam G.;Lee, Dongkyu
    • Steel and Composite Structures
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    • v.44 no.5
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    • pp.633-649
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    • 2022
  • This paper is first implemented with the bending behavior of three-dimensional functionally graded (3DFG) plates in the framework of level set-based topology optimization (LS-based TO). Besides, due to the suitable properties of the current design domain, the thin-plate spline (TPS) is recognized as a RBF to construct the LS function. The overall mechanical properties of the 3DFG plate are assessed using a power-law distribution scheme via Mori-Tanaka micromechanical material model. The bending response is obtained using the first-order shear deformation theory (FSDT). The mixed interpolation of four elements of tensorial components (MITC4) is also implemented to overcome a well-known shear locking problem when the thickness becomes thinner. The Hamilton-Jacobi method is utilized in each iteration to enforce the necessary boundary conditions. The mathematical formulas are expressed in great detail for the LS-based TO using 3DFG materials. Several numerical examples are exhibited to verify the efficiency and reliability of the current methodology with the previously reported literature. Finally, the influences of FG materials in the optimized design are explained in detail to illustrate the behaviors of optimized structures.

An Application of the Rough Set Approach to credit Rating

  • Kim, Jae-Kyeong;Cho, Sung-Sik
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 1999.10a
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    • pp.347-354
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    • 1999
  • The credit rating represents an assessment of the relative level of risk associated with the timely payments required by the debt obligation. In this paper, we present a new approach to credit rating of customers based on the rough set theory. The concept of a rough set appeared to be an effective tool for the analysis of customer information systems representing knowledge gained by experience. The customer information system describes a set of customers by a set of multi-valued attributes, called condition attributes. The customers are classified into groups of risk subject to an expert's opinion, called decision attribute. A natural problem of knowledge analysis consists then in discovering relationships, in terms of decision rules, between description of customers by condition attributes and particular decisions. The rough set approach enables one to discover minimal subsets of condition attributes ensuring an acceptable quality of classification of the customers analyzed and to derive decision rules from the customer information system which can be used to support decisions about rating new customers. Using the rough set approach one analyses only facts hidden in data, it does not need any additional information about data and does not correct inconsistencies manifested in data; instead, rules produced are categorized into certain and possible. A real problem of the evaluation of the evaluation of credit rating by a department store is studied using the rough set approach.

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A Robust Algorithm for Tracking Non-rigid Objects

  • Kim, Jong-Ryul;Na, Hyun-Tae;Moon, Young-Shik
    • Proceedings of the IEEK Conference
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    • 2002.07a
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    • pp.141-144
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    • 2002
  • In this paper, we propose a new object tracking algorithm using deformed template and Level-Set theory, which is robust against background variation, object flexibility and occlusion. The proposed tracking algorithm consists of two steps. The first step is an estimation of object shape and location, on the assumption that the transformation of object can be approximately modeled by the affine transform. The second step is a refinement of the object shape to fit into the real object accurately, by using the potential energy map and the modified Level Set speed function. Experimental results show that the proposed algorithm can track non-rigid objects with large variation in the backgrounds.

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Measuring Consumer Preferences Using Multi-Attribute Utility Theory (다속성 효용이론을 활용한 소비자 선호조사)

  • Ahn, Jae-Hyeon;Bang, Young-Sok;Han, Sang-Pil
    • Asia pacific journal of information systems
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    • v.18 no.3
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    • pp.1-20
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    • 2008
  • Based on the multi-attribute utility theory (MAUT), we present a survey method to measure consumer preferences. The multi-attribute utility theory has been used to make decisions in OR/MS field; however, we show that the method can be effectively used to estimate the demand for new services by measuring individual level utility function. Because conjoint method has been widely used to measure consumer preferences for new products and services, we compare the pros and cons of two consumer preference survey methods. Further, we illustrate how swing weighing method can be effectively used to elicit customer preferences especially for new telecommunications services, Multi-attribute utility theory is a compositional approach for modeling customer preference, in which researchers calculate overall service utility by summing up the evaluation results for each attribute. On the contrary, conjoint method is a decompositional approach, which requires holistic evaluations for profiles. Partworth for each attribute is derived or estimated based on the evaluation, and finally consumer preferences for each profile are calculated. However, if the profiles are quite new and unfamiliar to the survey respondents, they will find it very difficult to accurately evaluate the profiles. We believe that the multi-attribute utility theory-based survey method is more appropriate than the conjoint method, because respondents only need to assess attribute level preferences and not holistic assessment. We chose swing weighting method among many weight assessment methods in multi-attribute utility theory, because it is designed to perform in a simple and fast manner. As illustrated in Clemen and Reilly (2001), to assess swing weights, the first step is to create the worst possible outcome as a benchmark by setting the worst level on each of the attributes. Then, each of the succeeding rows "swings" one of the attributes from worst to best. Upon constructing the swing table, respondents rank order the outcomes (rows). The next step is to rate the outcomes in which the rating for the benchmark is set to be 0 and the rating for the best outcome to be 100, and the ratings for other outcomes are determined in the ranges between 0 and 100. In calculating weight for each attribute, ratings are normalized by the total sum of all ratings. To demonstrate the applicability of the approach, we elicited and analyzed individual-level customer preference for new telecommunication services-WiBro and HSDPA. We began with a randomly selected 800 interviewees, and reduced them to 432 because other remaining ones were related to the people who did not show strong intention for subscription to new telecommunications services. For each combination of content and handset, number of responses which favored WiBro and HSDPA were counted, respectively. It was assumed that interviewee favors a specific service when expected utility is greater than that of competing service(s). Then, the market share of each service was calculated by normalizing the total number of responses which preferred each service. Holistic evaluation of new and unfamiliar service is a tough challenge for survey respondents. We have developed a simple and easy method to assess individual level preference by estimating weight of each attribute. Swing method was applied for this purpose. We believe that estimating individual level preference will be quite flexibly used to predict market performance of new services in many different business environments.

The Effects of Symptoms from Emotional Airline Labors on Their Job-related Stress, Service Delivery Level and Customer-Oriented Work Activities (항공사 종사자의 감정노동이 직무스트레스와 서비스 제공수준, 고객 지향적 행동에 미치는 영향)

  • Kim, Kwang Il;Lee, Su Mi
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.25 no.4
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    • pp.76-82
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    • 2017
  • I studied existing research and thesis which are relating emotional labor, job-related stress, and service level to set up the structural model and potential factors that form this structural model. The result showed that emotional labor is affecting job-related stress, service delivery level and customer-oriented activities. And service delivery level is affecting customer-oriented activities under 95% confidence levels. Also from the analysis of group survey by working group, check-in agent's emotional labor is affecting on job-related stress, service delivery level and customer-oriented activities. And service level is affecting on customer-oriented activities. By the result of how emotional labor and customer-oriented activities are related, I strongly believe it contributed the study of emotional labor theory.

A Case Study on Item Analysis and Standard Setting of the Physics Basic Ability Test for Engineering College Students (공학계열 대학생 물리 기초학력평가 문항분석 및 성취수준 설정 사례연구)

  • Lee, Keumho;Jung, Hyekyung
    • Journal of Engineering Education Research
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    • v.26 no.6
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    • pp.40-50
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    • 2023
  • This study is to examine the validity of assessing basic-level proficiency in physics among incoming engineering freshmen through item analysis and standard setting. For empirical analysis, we examined the physics subject taken by the freshman class of 2021 at K University, considering its significance for engineering students. In this study, we initially performed item analysis utilizing both classical test theory and item response theory. Subsequently, leveraging the item and test information, we employed a modified Angoff method and the Bookmark method for standard setting. Consequently, the difficulty level initially set during item development was found to be higher than the actual performance level exhibited by the students. This study highlights a discernible disparity between the expected university standard and the real proficiency level of incoming freshmen in terms of basic academic ability in physics. Based on these research findings, a comprehensive discussion on the fundamental academic competence of engineering students was conducted, underscoring the necessity for formulating a tailored learning approach leveraging the outcomes from the basic ability test.

A Study on Subjective Nise Evaluation of Rdesidential Area on Aircraft Noise near Airport - Case Study on Taegu Airport - (공항 인근주민들의 항공기소음에 대한 피해의식 구조에 관한 연구 - 대구공항을 사례지역으로 -)

  • 김재석
    • Journal of KSNVE
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    • v.10 no.1
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    • pp.41-48
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    • 2000
  • Evaluation model for damage consciousness was established through the survey of 2,210 residents' consciousness on aircraft noise near Taegu Airport. There were none who replied that the level of the aircraft noise was as los as it was quiet. 77(3.5%) people replied the noise was normal, and 2,133(95.5%) people said it was noisy. As to the period of time when the aircraft noise occurred, 51%, 97%, 86%, 0.6% of the residents pointed out the morning time, the day time, the evening time, and the night time, respectively. Because of aircraft noise, 73%, 88%, 70%, 77%, 78%, and 33% of the residents felt it disturbing indoor conversation, telephoning, watching TV or listening to the ratio, reading or meditating, working, sleeping, and studying, respectively. It was examined that the bad effects of aircraft noise on the health were severe : 43% of the resident said they experienced embarrassment. 52% astonishment, 66% absence of mind, 61% heart-beating. 77% headaches, 78% earache, and 93% displeasure. For the survey of the residents' damage consciousness about aircraft noise, the level of aircraft noise was set as an objective variable, and gender, age, occupation. Education, the type of house, the structure of windows, the consciousness of settlement in the district, and the period of residence were set as explanatory variables. And the quantification theory I was applied to the analysis. The most influencing factor of the damage consciousness on aircraft noise was the education, the second occupation, the third age, the forth the consciousness of settlement, the fifth the period of residence, the sixth gender, the seventh the type of house, and the least influencing factor among them was the structure of windows. These findings will be a useful guideline when the government seeks to set up policies which will help solve the resident's noise problems near Taegu Airport.

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The Concept of Fashion Coordination (의상연출학의 개념 정립)

  • 김미영
    • Journal of the Korean Society of Clothing and Textiles
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    • v.20 no.6
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    • pp.1178-1192
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    • 1996
  • The purpose of this study is to develop the fashion coordination course. The first step of this study is to set up the concept of fashion coordination. And the second step is to organize the fashion coordination course depending on the concept of fashion coordination. The concept of the fashion coordination is as foltowed: The goal of the fashion coordinapion is 'making the image' The image in this study is constituted of several concepts, which are perception/conition/impression, bojective/person perception, external/internal content, and simple/complex level. The elements of fashion coordination are the person, the clothing and the accessory. The method of making the image with elements is to harmonize the symbolic aspect of elements, and the beauty aspect of elements too. The fashion coordination course is organized into theory part and practice part. The theory part is composed of theories of 'making the image', the elements, the harmony depending on the concept of fashion coordination. The practice part is composed of exercises to make the image depending on the theory, especially the important point of exercise is Listing the clues that make the image.

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Fuzzy Theory and Reservoir Operation Guidelines for Agricultural Purposes (퍼지이론과 관개용 저수지의 조작)

  • 정하우;이남호
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.33 no.4
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    • pp.45-51
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    • 1991
  • The objective of this paper is to show how the fuzzy sets theory can be applied to the reservoir operation guidelines for agricultural purposes. The concepts of the theory has been resented as a new tool for the decision problems which contains fuzziness and it's application can be found in operations research, expert systems, robotics, fuzzy computers, and pattern recognition. The fuzzy control system for the reservoir operation composed of a set of reservoir operation rules and a fuzzy inference engine was built. Water demand for paddy fields, water availability, and inflow to a reservoir were selected as main factors which determine the magnitude of reservoir release. The behavior of the control system was evaluated for different level of water demand and the results seemed to be reasonable.

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