• Journal of the Korean Data and Information Science Society
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• 제17권2호
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• pp.609-617
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• 2006

A new fuzzy c-regression algorithm for switching regression analysis is presented, which combines fuzzy c-means clustering and least squares support vector machine. This algorithm can detect outliers in switching regression models while yielding the simultaneous estimates of the associated parameters together with a fuzzy c-partitions of data. It can be employed for the model-free nonlinear regression which does not assume the underlying form of the regression function. We illustrate the new approach with some numerical examples that show how it can be used to fit switching regression models to almost all types of mixed data.

• Journal of the Korean Statistical Society
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• 제35권2호
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• pp.115-142
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• 2006

This paper studies the problem of option hedging when the underlying asset price process is a compound Poisson process. By adopting an asymptotic approach to let the security price converge to a continuous process, we find a closed-form hedging strategy that improves the classical Black-Scholes hedging strategy in a quadratic sense. We first show that the scaled Black-scholes hedging error has a limit in law, and that limit is decomposed into a part that can be traded away and a part that is purely unreplicable. The Black-Scholes hedging strategy is then modified by adding the replicable part of its hedging error and by adding the mean-variance hedging strategy to the nonreplicable part. Some results of simulation experiment s are also provided.

• 한국임상수의학회지
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• 제17권1호
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• pp.129-133
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• 2000

Based on pathological findings, 5 German shepherds, revealed a mean age of 7.6 years, showing no clinical signs were diagnosed as tracheopathia osteochondroplastica(TOC). Grossly, multiple small-sizecd nodules, appeared as cobble-stones, on the cartilage rings situated in the anterior trachea and the mucosal surface of the epiglottis were showed. Numerous tiny nodules were scattered on the pleural surface of the lung. The vascular walls of the heart were irregular and coarse apearance with calcification. Histopathologically, nodules in the trachea represented an irregular expansion of the underlying tracheal ring with protrusion into the submucosa and consisted of proliferated and calcified cartilage and bone with marrow spaces containing numbers of hematopoietic cells. Pulmonary calcinosis and calcification of the vascular walls of the heart were observed. Our observations suggested that TOC arises form eccondroses and exostoses of the tracheal cartilage rings.

• 한국생산제조학회지
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• 제5권2호
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• pp.57-62
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• 1996

Basically, the idea underlying most edge-detection technique is the computation of a local derivative operator used for edge detection in gray level image. This concept can be easily illustrated with the aid of object which shows an image of a simple lilght on a dark background, Using the gray level profile along a horizontal scan line of the image. the first and second derivatives of it were acquired. This study is to develop an automatic measuring system based on the digital image processing which can be applied to the real time measurement of the characteristics of the ultra-thin thickness. The experimental results indicate that the developed automatic inspection can be applied in real situation.

• Journal of Chest Surgery
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• 제28권11호
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• pp.1019-1024
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• 1995

Clinical analysis were performed on 68 cases of subcutaneous emphysema, those were visited at the emergency center of Chosun university hospital during the period form 1992 to 1994. The following result was obtained. 1 The incidence of subcutaneous emphysema was 0.16%, and male was dominant [M:F=6.9:1 .2 The age distribution of subcutaneous emphysema was from 4 to 77 years old and mean age was 49.6$\pm$17.8 years[$\pm$SD 3 The most presenting symptoms were chest pain[49% , and the proceeding cause was traffic accident[38% . 3 The most associated disease was a ipsilateral pneumothorax[59% . 4 Conservative management is an indication in the majority of cases of subcutaneous emphysema because it is usually a self-limited condition and spontaneous remission usually occurs. We conclude that initial effort must be made to detect the underlying cause of the subcutaneous emphysema in order that appropriate management may be undertaken.

• 한국전자거래학회지
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• 제1권1호
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• pp.27-50
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• 1996

In this paper. we present a definition of the term virtual enterprise (VE) and discuss some related terms and concepts. The definition was given based on Porter's Value Chain Theory. Then we discuss some positioning strategies for entering or joining a virtual enterprise from an executive's viewpoint. which show a framework for making decisions on for what. when and how a (real) enterprise need to participate or form a virtual enterprise and whom the partners should be. The major pert of the paper is on underlying information technologies and architectures for building virtual enterprises. Requirements for modeling virtual enterprises and core technologies needed for implementation are discussed. A virtual enterprise reference architecture based on NIIIP's model is presented. Finally we discuss some points that should. addressed from a macroeconomic and public policies viewpoints. These are the issues of IT standardization and investments in IT infrastructure.

• 한국지구과학회지
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• 제38권6호
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• pp.427-441
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• 2017

Theory of Earth's free oscillation is revisited. Firstly, we summarized the underlying formulations, such as the equation of motion and its conversion into numerically integrable form and then explained computational procedures including the treatment of inner core-outer core boundary and core-mantle boundary, while the latter information has not been explicitly given in most publications. Secondly, we re-calculated the periods of Earth's free oscillation modes (period >200 s) for PREM model. In doing so we acquired the values of modes missing in Dziewonski and Anderson (1981). As a case observation, one seismogram after 2011 Tohoku earthquake recorded at Daejeon, Korea (KIGAM seismic station) was briefly analyzed to identify free oscillation mode excitations on its spectra. The material in this article will be most clear guide for those on calculating the Earth's free oscillation mode.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2002년도 춘계학술발표대회 발표논문초록집
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• pp.22-22
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• 2002

Identification of spermatogonial stern cell-specific surface molecules is important in understanding the molecular mechanisms underlying the maintenance and differentiation of these cells. We have found that spermatogonia from busulfan treated mice expressed an autoantigen that distinguishes between undifferentiated and differentiated spermatogonia. Four to six weeks after busulfan treatment, germ cells located in the basal compartment of seminiferous epithelium show isotype-specific IgG deposits that form due to autoimmunity. (omitted)

• Structural Engineering and Mechanics
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• 제25권3호
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• pp.331-345
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• 2007

Uncertainties enter a complex analysis from a variety of sources: variability, lack of data, human errors, model simplification and lack of understanding of the underlying physics. However, for many important engineering applications insufficient data are available to justify the choice of a particular probability density function (PDF). Sometimes the only data available are in the form of interval estimates which represent, often conflicting, expert opinion. In this paper we demonstrate that Bayesian estimation techniques can successfully be used in applications where only vague interval measurements are available. The proposed approach is intended to fit within a probabilistic framework, which is established and widely accepted. To circumvent the problem of selecting a specific PDF when only little or vague data are available, a hierarchical model of a continuous family of PDF's is used. The classical Bayesian estimation methods are expanded to make use of imprecise interval data. Each of the expert opinions (interval data) are interpreted as random interval samples of a parent PDF. Consequently, a partial conflict between experts is automatically accounted for through the likelihood function.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1510-1515
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• 2005

This paper is concerned with a Logic-based Fuzzy Neural Networks (LFNN) with the aid of fuzzy granulation. As the underlying design tool guiding the development of the proposed LFNN, we concentrate on the context-based fuzzy clustering which builds information granules in the form of linguistic contexts as well as OR fuzzy neuron which is logic-driven processing unit realizing the composition operations of T-norm and S-norm. The design process comprises several main phases such as (a) defining context fuzzy sets in the output space, (b) completing context-based fuzzy clustering in each context, (c) aggregating OR fuzzy neuron into linguistic models, and (c) optimizing connections linking information granules and fuzzy neurons in the input and output spaces. The experimental examples are tested through two-dimensional nonlinear function. The obtained results reveal that the proposed model yields better performance in comparison with conventional linguistic model and other approaches.