• Title/Summary/Keyword: Level- Set theory

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A Robust Algorithm for Tracking Non-rigid Objects Using Deformed Template and Level-Set Theory (템플릿 변형과 Level-Set이론을 이용한 비강성 객체 추적 알고리즘)

  • 김종렬;나현태;문영식
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.40 no.3
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    • pp.127-136
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    • 2003
  • In this paper, we propose a robust object tracking algorithm based on model and edge, using deformed template and Level-Set theory. The proposed algorithm can track objects in case of background variation, object flexibility and occlusions. First we design a new potential difference energy function(PDEF) composed of two terms including inter-region distance and edge values. This function is utilized to estimate and refine the object shape. The first step is to approximately estimate the shape and location of template object based on the assumption that the object changes its shape according to 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. The experimental results show that the proposed algorithm can track non-rigid objects under various environments, such as largely flexible objects, objects with large variation in the backgrounds, and occluded objects.

Analysis of the margin level in the KOSPI200 futures market (KOSPI200 선물 시장의 증거금 수준에 대한 연구)

  • Kim, Jun;Choe, In-Chan
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2004.05a
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    • pp.734-737
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    • 2004
  • When the margin level is set relatively low, margin violation probability increases and the default probability of the futures market rises. On the other hand, if the margin level is set high, the margin violation probability decreases, but the futures market becomes less attractive to hedgers as the investor's opportunity cost increases. In this paper, we investigate whether the movement of KOSPI200(Korea Composite Stock Price Index 200) futures daily prices can be modeled with the extreme value theory. Base on this investigation, we examine the validity of the margin level set by the extreme value theory. Computational results are presented to compare the extreme value distribution and the empirical distribution of margin violation in KOSPI200. Some observations and implications drawn from the computational experiment are also discussed.

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A Fuzzy-Goal Programming Approach For Bilevel Linear Multiple Objective Decision Making Problem

  • Arora, S.R.;Gupta, Ritu
    • Management Science and Financial Engineering
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    • v.13 no.2
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    • pp.1-27
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    • 2007
  • This paper presents a fuzzy-goal programming(FGP) approach for Bi-Level Linear Multiple Objective Decision Making(BLL-MODM) problem in a large hierarchical decision making and planning organization. The proposed approach combines the attractive features of both fuzzy set theory and goal programming(GP) for MODM problem. The GP problem has been developed by fixing the weights and aspiration levels for generating pareto-optimal(satisfactory) solution at each level for BLL-MODM problem. The higher level decision maker(HLDM) provides the preferred values of decision vector under his control and bounds of his objective function to direct the lower level decision maker(LLDM) to search for his solution in the right direction. Illustrative numerical example is provided to demonstrate the proposed approach.

A Study on the Negotiation on Management Normalization of GM Korea through the Two-Level Games (양면게임 이론으로 분석한 한국GM 경영정상화 협상연구)

  • Lee, Ji-Seok
    • Korea Trade Review
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    • v.44 no.1
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    • pp.31-44
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    • 2019
  • This study examines the normalization of Korean GM management between the Korean government and GM in terms of external negotiation game and internal negotiation game using Putnam's Two-Level Games. In addition, GM's Win-set change and negotiation strategy were analyzed. This analysis suggested implications for the optimal negotiation strategy for mutual cooperation between multinational corporations and local governments in the global business environment. First, the negotiation strategy for Korea's normalization of GM management in Korea can be shifted to both the concession theory and the opposition theory depending on the situation change and the government policy centered on the cautious theory. Second, GM will maximize its bargaining power through 'brink-end tactics' by utilizing the fact that the labor market is stabilized, which is the biggest weakness of the Korean government, while maintaining a typical Win-set reduction strategy. GM will be able to restructure at any time in terms of global management strategy, and if the financial support of the Korean government is provided, it will maintain the local factory but withdraw the local plant at the moment of stopping the support. In negotiations on the normalization of GM management in Korea, it is necessary to prepare a problem and countermeasures for various scenarios and to maintain a balance so that the policy does not deviate to any one side.

Study on Safe Set and Maneuverability Envelope Protection during Arresting Landing

  • Liu, Zidong;Zhan, Hao;Wang, Shuang
    • International Journal of Aerospace System Engineering
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    • v.2 no.2
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    • pp.73-78
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    • 2015
  • According to the characteristic of carrier-based aircraft, the method of solving safe set during arresting landing is discussed in this paper based on optimal control and invariant set theory. The safe sets of carrier aircraft are evaluated in different states on the characteristic of longitudinal augmented system by using the level set method. Then, the influence on the boundary of safe set under various factors is analyzed. At last, the maneuverability envelope protection is established based on the corresponding theory, and the validity of the system is verified through simulation. The results demonstrate preliminarily that: compared with mass and thrust, the elevator is the greatest influence factor for the boundary of safe set; the dynamic trajectory of carrier-based aircraft can be located at the interior of safe set effectively with the maneuverability envelope protection.

ROUGH SET THEORY APPLIED TO INTUITIONISTIC FUZZY IDEALS IN RINGS

  • Jun, Young-Bae;Park, Chul-Hwan;Song, Seok-Zun
    • Journal of applied mathematics & informatics
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    • v.25 no.1_2
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    • pp.551-562
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    • 2007
  • This paper concerns a relationship between rough sets, intuitionistic fuzzy sets and ring theory. We consider a ring as a universal set and we assume that the knowledge about objects is restricted by an intuitionistic fuzzy ideal. We apply the notion of intutionistic fuzzy ideal of a ring for definitions of the lower and upper approximations in a ring. Some properties of the lower and upper approximations are investigated.

Study on the Phase Interface Tracking Numerical Schemes by Level Set Method (Level Set 방법에 의한 상경계 추적 수치기법 연구)

  • Kim, Won-Kap;Chung, Jae-Dong
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.116-121
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    • 2006
  • Numerical simulations for dendritic growth of crystals are conducted in this study by the level set method. The effect of order of difference is tested for reinitialization error in simple problems and authors founded in case of 1st order of difference that very fine grids have to be used to minimize the error and higher order of difference is desirable to minimize the reinitialization error The 2nd and 4th order Runge-Kutta scheme in time and 3rd and 5th order of WENO schemes with Godunov scheme are applied for space discretization. Numerical results are compared with the analytical theory, phase-field method and other researcher's level set method.

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An Experimental Study on Fuzzy Document Retrieval System (퍼지개념을 적용한 질의식의 분석과 문헌정보 검색에 관한 연구)

  • Lee Seung Chai
    • Journal of the Korean Society for Library and Information Science
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    • v.21
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    • pp.249-290
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    • 1991
  • Theoretical developments in the information retrieval have offered a number of alternatives to traditional Boolean retrieval. Probability theory and fuzzy set theory have played prominent roles here. Fuzzy set theory is an attempt to generalize traditional set theory by permitting partial membership in a set and this means recognizing different degrees to which a document can match a request. In this study, an experimentation of a document retrieval system using the fuzzy relation matrix of the keywords is described and the results are offered. The queries composed of keywords and Boolean operaters AND, OR, NOT were processed in the retrieval method, and the method was implemented on the PC of 32bit level (30 MHz) in an experimental system. The measurement of the recall ratio and precision ratio verified the effectiveness of the proposed fuzzy relation matrix of keywords and retrieval method. Compared to traditional crisp method in the same document database, the recall ratio increased $10\%$ high although the precision ratio decreased slightly. The problems, in this experiment, to be resolved are first, the design of the automatic data input and fuzzy indexing modules, through which the system . can have the ability of competition and usefulness. Second, devising a systematic procedure for assigning fuzzy weights to keywords in documents and in queries.

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Analysis of the maintenance margin level in the KOSPI200 futures market (KOSPI200 선물 유지증거금률에 대한 실증연구)

  • Kim, Joon;Kim, Young-Sik
    • Journal of the Korean Society of Industry Convergence
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    • v.8 no.2
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    • pp.85-95
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    • 2005
  • The margin level in the futures market platys an important role in balancing the default probability with the investor's opportunity cost. In this paper, we investigate whether the movement of KOSPI200 futures daily prices can be modeled with the extreme value theory. Based on this investigation, we examine the validity of the margin level set by the extreme value theory. Moreover, we propose an expected profit-maximization model for securities companies. In this model, the extreme value theory is used for cost estimation, and a regression analysis is used for revenue calculation. Computational results are presented to compare the extreme value distribution with the empirical distribution of margin violation in KOSPI200 and to examine the suitability of the expected profit-maximization model.

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The Effect of Construal Level on Variety Seeking across Subcategories

  • Suh, Jiyeon;Won, Eugene J.S.
    • Asia Marketing Journal
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    • v.21 no.3
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    • pp.1-20
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    • 2019
  • The present study investigates how consumers' construal level affects their variety seeking behavior when choosing multiple items simultaneously. Especially the authors focus on the perceptual level at which variety seeking takes place and propose that variety seeking can take place not only at brand level but also at category or subcategory level. Categorical variety seeking refers to diversification of one's choices over multiple brands not within the same category but across multiple categories. Building on construal level theory, the authors expected that people engaging in higher-level construals tend to subcategorize the choice set and distribute their choices across more subcategories and designed four experiments to test the related hypotheses. The experimental results showed that consumers' construal level can affect the level at which variety seeking takes place and those with higher construal level tend to choose options seemingly more dissimilar to each other.