• 제어로봇시스템학회논문지
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• 제17권8호
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• pp.777-782
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• 2011

Neural network technique is widely employed in the fields of signal processing, control systems, pattern recognition, etc. Learning of neural networks is an important procedure to accomplish dynamic system modeling. This paper presents a novel learning approach for differential neural network models based on the Kalman-Bucy filter theory. We construct an augmented state vector including original neural state and parameter vectors and derive a state estimation rule avoiding gradient function terms which involve to the conventional neural learning methods such as a back-propagation approach. We carry out numerical simulation to evaluate the proposed learning approach in nonlinear system modeling. By comparing to the well-known back-propagation approach and Kalman-Bucy filtering, its superiority is additionally proved under stochastic system environments.

• Structural Engineering and Mechanics
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• 제75권2호
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• pp.239-246
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• 2020

In this paper, a novel analytical method, Max-Min Approach (MMA), has been presented and applied to consider the nonlinear vibration of dry cask storage systems. The nonlinear governing equation of the structure has been developed using the shell theory. The MMA results are compared with numerical solutions derived by Runge-Kutta's Method (RKM). The results indicate a satisfying agreement between MMA and numerical solutions. Parametric studies have been conducted on the nonlinear frequency of dry casks. The phase-plan of the problem is also presented and discussed. The proposed approach can potentially ca be extended to highly nonlinear problems.

• 한국언어정보학회지:언어와정보
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• 제5권1호
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• pp.87-105
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• 2001

This paper categorizes currently available theories of focus into two major types a 'discourse structure approach'(DSA) and a 'sentence structure approach'(SSA) The former DSA is intended to refer to a type of approach that analyzes focus only in terms of the discourse structure in which a focused sentence occurs. The alternative semantics approach which is the most widely available theory of focus belongs to this The latter SSA is meant to refer to a type of theory that analyzes focus in terms of sentence-internal structure, This study supports the SSA be revealing some empirical problems of the DSA that arise is analyzing two different kinds of focus, the A-accented focus and the B-accented focus (contrastive topic), and provides a brief sketch of a comprehensive analysis of focus and contrastive topic.

• ETRI Journal
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• 제36권6호
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• pp.1023-1031
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• 2014

Failure analysis is necessary to clarify the root cause of a failure, predict the next time a failure may occur, and improve the performance and reliability of a system. However, it is not an easy task to analyze and interpret failure data, especially for complex systems. Usually, these data are represented using many attributes, and sometimes they are inconsistent and ambiguous. In this paper, we present a scalable approach for the analysis and interpretation of failure data of high-performance computing systems. The approach employs rough sets theory (RST) for this task. The application of RST to a large publicly available set of failure data highlights the main attributes responsible for the root cause of a failure. In addition, it is used to analyze other failure characteristics, such as time between failures, repair times, workload running on a failed node, and failure category. Experimental results show the scalability of the presented approach and its ability to reveal dependencies among different failure characteristics.

• 성인간호학회지
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• 제14권2호
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• pp.244-255
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• 2002

Purpose: This study was to understand to the nursing theory frame contained in the traditional philosophy and western nursing theory for the theory development fit for Korean people and to identified the strategy for nursing theory development. Method: To perform this study various relevant texts-western, eastern, classical and contemporary were reviewed. Result: The metaparadigm of the nursing in western considers four major factors-Human being, Environment, Health and Nursing. In Korea, the metaparadigm of nursing considers three major factors-Universe, Human being (body, life, health, disease) and Nursing. The key strategy for establishing comprehensive nursing theory which combines both western and eastern is to study the nursing literature based on eastern and western philosophy. Theorists should study the life and culture of the specific nation in order to understand the essence of the thoughts and psychology of the patients and to investigate the phenomena, which will be the foundation of theory development. Conclusion: Western nursing theory must be utilized to provide practical framework for the development of nursing theory, and practical approach is necessary for combining western and eastern theory.

• Coupled systems mechanics
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• 제11권2호
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• pp.167-198
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• 2022

In this paper we deal with classical instability problems of heterogeneous Euler beam under conservative loading. It is chosen as the model problem to systematically present several possible solution methods from simplest deterministic to more complex stochastic approach, both of which that can handle more complex engineering problems. We first present classical analytic solution along with rigorous definition of the classical Euler buckling problem starting from homogeneous beam with either simplified linearized theory or the most general geometrically exact beam theory. We then present the numerical solution to this problem by using reduced model constructed by discrete approximation based upon the weak form of the instability problem featuring von Karman (virtual) strain combined with the finite element method. We explain how such numerical approach can easily be adapted to solving instability problems much more complex than classical Euler's beam and in particular for heterogeneous beam, where analytic solution is not readily available. We finally present the stochastic approach making use of the Duffing oscillator, as the corresponding reduced model for heterogeneous Euler's beam within the dynamics framework. We show that such an approach allows computing probability density function quantifying all possible solutions to this instability problem. We conclude that increased computational cost of the stochastic framework is more than compensated by its ability to take into account beam material heterogeneities described in terms of fast oscillating stochastic process, which is typical of time evolution of internal variables describing plasticity and damage.

• Structural Engineering and Mechanics
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• 제39권4호
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• pp.449-463
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• 2011

A free vibration analysis is made of a moderately-thick toroidal shell based on a shear deformation (Timoshenko-Mindlin) shell theory. This work represents an extension of earlier work by the authors which was based on a thin (Kirchoff-Love) shell theory. The analysis uses a modal approach in the circumferential direction, and numerical results are found using the differential quadrature method (DQM). The analysis is first developed for a shell of revolution of arbitrary meridian, and then specialized to a complete circular toroidal shell. A second analysis, based on the three-dimensional theory of elasticity, is presented to cover thick shells. The shear deformation theory is validated by comparing calculated results with previously published results for fifteen cases, found using thin shell theory, moderately-thick shell theory, and the theory of elasticity. Consistent agreement is observed in the comparison of different results. New frequency results are then given for moderately-thick and thick toroidal shells, considered to be completely free. The results indicate the usefulness of the shear deformation theory in determining natural frequencies for toroidal shells.

• 한국정보시스템학회지:정보시스템연구
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• 제30권4호
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• pp.173-202
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• 2021

Purpose This study explored overall phenomena in context such as YouTube channel operation, strategy, and profit generation through interviews with two research participants who started their own businesses and are recognized as influencer on YouTube and analysis of viewer responses to uploaded contents. With the explosive growth of YouTube content provision and use, previous studies on YouTube are only being conducted individually on YouTube's content, influence, and content providers, so it is need to explore YouTube channel operations and the effect of revenue generation in context from an integrated perspective. Therefore, the purpose of this study is to present an integrated model that provides a specific process by contextually linking the factors and results influencing YouTube channel operation and revenue generation phenomena to individuals and companies who are trying to operate YouTube channels for the first time. Design/methodology/approach This study systematized and structured the overall phenomena in context such as YouTube channel operation, communication strategy, effect on revenue generation, and YouTube channel operation results by selecting interview subjects and collecting data through interviews, and analyzing viewer reactions (likes, comments, etc.). Due to the lack of previous studies exploring integrated phenomena, research analysis used Strauss & Corbin (1998)'s grounded theory approach, which presented inductive research methods to discover new theories by structuring concepts and categories based on detailed observations and information provided by interviewees. Findings The academic implication of this study is that while previous studies are conducted as individual studies on YouTube's content, influence, and content providers in the current situation where YouTube content provision and use are exploding, it integrally explores and presents an integrated model throughout the process. In addition, taking into account the lack of previous studies, it can be found in the aspect of using the grounded theory approach, an inductive theory approach that establishes a new theory. The practical implications can be found in that it presented practical directions to beginners who want to start operating YouTube channels by identifying operational preparations, communication strategies with viewers, and response management strategies.

• 대한지리학회지
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• 제40권4호
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• pp.387-401
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• 2005

본 연구는 영미 관광지리학 분야의 연구경향에 대하여 문헌연구법을 통해 통시적 고찰을 시도했다. 본 논문의 목적은 영미 관광지리학 연구흐름을 연구접근법과 주요 연구주제를 중심으로 고찰하고 연구동향을 파악함으로써, 한국 관광지리학 계에 미치는 시사점을 도출하는 데 있다. 영미 관광지리학 연구흐름의 변화는 지리학 패러다임의 변화와 밀접한 관련을 맺고 있는데, 연구동향의 변화를 크게 구분지어 보면 (1) 경험주의적 접근법, (2) 논리실증주의적 접근법, (3) 인본주의적 접근법, (4) 비판주의적 접근법의 네 가지로 분류된다. 주요 연구주제들로는 경험주의적 접근법에서는 관광지역에 대한 자세한 묘사를 통한 현황설명, 논리실증주의적 접근에서는 공간분석과 진화론적 연구, 인본주의적 접근에서는 관광객 행태, 장소성의 문제, 비판주의적 접근에서는 관광의 상품화, 관광객의 시선 등이다. 최근 영미 관광지리학의 연구경향은 가치중립적인 응용지리학적 연구와 가치지향적인 비판주의적 연구가 맞서는 경향을 보이고 있으며 관광산업의 성장, 지리학과 관광의 밀접한 연관성, 영미 관광지리학자들의 활발한 활동 등으로 인해 관광지리학은 꾸준한 성장을 이룰 것으로 예상된다.

• Journal of Information Technology Applications and Management
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• 제16권4호
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• pp.93-107
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• 2009

This study investigated consumer preferences for Internet medical information service in China using the multi-attribute utility theory. The multi-attribute utility theory is a compositional approach for modeling consumer preferences wherein researchers calculate the overall service utility by summing up the evaluation results for each attribute. We found that Chinese Internet medical information users consider the availability of information and quick response to be the most important attributes. Further, they think that the comment feature is less important as compared to other attributes such as costs and updates. In addition, we found that the Internet users having more Internet experience consider these attributes to be more important as compared to the people who are just beginning to surf the Internet. For any successful Internet business, Internet marketers should assess individual-level preference and accordingly organize a fresh campaign. As of now, Internet marketers need estimation methods to predict the market performance of new services in many different business environments. We believe that the multi-attribute utility theory is a useful approach in this regard.