• Journal of Advanced Marine Engineering and Technology
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• v.19 no.3
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• pp.77-83
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• 1995

Recently, in the field of industrial servo-systems, several methods have been proposed for tracking the reference input fastly and finely without overshoot. These methods, however, are established under hypothesis that structure and parameters of the plant are known accurately and they are time invariant. In practice, it is difficult to obtain the values of plant's parameters accurately and usually plants change with time and operation conditions. In this paper a method to construct the nominal model tracking adaptive control system is proposed. The system is composed of the nomial model which produces a ideal response and the model tracking system with the fuzzy adaptive controller. If the actual plant is equal to the controlled object in the nominal model, the output of the plant is the same as that of the nominal model and the fuzzy adaptive controller becomes idle. However, when the plant changes, the fuzzy adaptive controller of the tracking system operates in order for the output of the plant to track the ideal response. Through the computer simulations under various conditions, it is confirmed that the proposed model tracking system is very effective.

• 한국벤처창업학회:학술대회논문집
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• 2016.04a
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• pp.180-184
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• 2016

본 연구에서는 예비창업자의 심리적 특성 중 실패에 대한 두려움이 계획된 행동모델의 변수들을 매개로 하여 미래의 창업의도에 미치는 영향을 살펴보았다. 창업의도와 관련된 기존의 선행연구들은 많이 있었으나 주로 창업성공에 영향을 미치는 요인, 창업의도를 높이는 요인을 중심으로 연구가 진행되고 있음을 발견하였다. 이에 본 연구에서는 실패에 대한 두려움이 기업가적 활동을 수행함에 있어 본질적으로 내재되어 있는 요인임에도 불구하고 상대적으로 연구에서는 소홀하게 다루어졌던 것에 주목하여 실패에 대한 두려움을 측정하는 PFAI(Performances Failure Appraisal Inventory) 척도를 사용, 예비창업자의 실패에 대한 두려움이 창업의도에 미치는 영향을 창업에 대한 태도, 주관적 규범, 행동의도 등을 매개로 하여 실증하였다. 또한 실패에 대한 두려움을 상쇄시키는 역할로써 창업교육의 효과성을 살펴보았다. 이를 위해 서울 시내 대학생들을 중심으로 구조화된 설문지를 이용하여 자료를 수집 하였고, 수집된 자료는 AMOS 18.0 프로그램을 사용하여 분석하였다. 연구결과는 다음과 같다. 첫째, 실패에 대한 두려움은 창업에 대한 태도와 주관적 규범에 각각 부(-)의 영향을 미쳤다. 둘째, 창업에 대한 태도와 주관적 규범은 창업의도에 정(+)의 영향을 미치는 것으로 나타나 선행연구와 일치하는 결과를 보였다. 셋째, 실패에 대한 두려움은 창업의도에 직접적인 영향을 미치기보다는 계획된 행동모델의 구성요소인 창업에 대한 태도와 주관적 규범을 매개로 하여 각각 영향을 미쳤다. 넷째, 창업교육이 실패에 대한 두려움과 창업의도와의 관계를 조절하는지 분석한 결과 창업교육을 수강한 집단에게서 실패에 대한 두려움이 창업에 대한 태도와 주관적 규범에 미치는 부정적인 영향이 더 크게 나타났다.

• Journal of Internet Computing and Services
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• v.12 no.4
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• pp.145-156
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• 2011

The purpose of the study is to analyze the factors which cause the deviations of e-piracy. For this, empirical data were collected by conducing a field survey with a total of 531 collegians, and a Structural Equation Model was used for the purpose of analyzing the data acquired by that. A Structural Equation Model was designed and constructed by such factors as Anonymous Environment, Norm-Consciousness, and Recognition on Penalty, which are considered as the direct variables. In addition, the factor of Anonymous Environment was set as a variable for the factors of both Norm-Consciouness and Recoginition on Penalty. These are the results of the analysis; it is found that Anonymous Environment is the direct cause of e-piracy, but the other two factors are not statistically significant. And it is also found that Anonymous Environment gives a direct influence on the other factors of Norm-Consciousness and Recognition on Penalty and it also gives indirect influence on the factor of Recognition on Penalty by means of the factor of Norm-Consciousness. Therefore, in order to prevent e-piracy, it is required to provide the proper opportunity to be trained to observe norms under the environment of anonymity. For this, diverse and effectual teaching methods for information ethic education should be sought.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.1
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• pp.124-132
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• 2004

A hydraulic system is difficult to keep the performance due to non-linearity, load pressure which changes according to working condition and system parameter variation, the requirement of control algorithm has been risen in order to satisfy them. An adaptive control is a control method which is suggested to achieve a control object though plant characteristics change. In spite of the case that plant characteristics and the degree of variation are difficult to grasp, adaptive control can keep the characteristics of closed-loop system regularly. In this study GMVAC(generalized minimum variance adaptive control) combined with output error feedback is proposed in order to solve problems of non-minimum phase, vibration and overshoot in initial response of the plant. The control performance according to the variation of characteristics of the plant is evaluated by changing the supply pressure only.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.5
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• pp.564-570
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• 2003

This paper presents an adaptive fuzzy control scheme for nonlinear helicopter system which has uncertainty or unknown variations in parameters. The proposed adaptive fuzzy controller is a model reference adaptive controller. The parameters of fuzzy controller are adjusted so that the plant output tracks the reference model output. It is shown that the adaptive law guarantees the stability of the closed-loop system by using Lyapunov function. Several experiments with a small model helicopter having parameter variations are performed to show the usefulness of the proposed adaptive fuzzy controller.

• Proceedings of the Korea Association of Information Systems Conference
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• 2005.12a
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• pp.249-257
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• 2005

본 연구는 e-marketplace에 대해 기업이 지각하는 만족이 신뢰, 다차원적 관계몰입(감정적몰입, 지속적몰입, 규범적몰입)에 영향을 미칠 수 있음을 제안하고 이를 실증 분석하였다. 전체적으로 제안모델은 수용할만한 자료적합도를 보여 주었으며, 제시한 4개의 가설 모두가 유의한 것으로 나타났다. 그리고 간접효과를 분석한 결과 만족이 신뢰를 통해서 다차원적 관계몰입(감정적몰입, 지속적몰입, 규범적몰입)에 간접적인 영향을 미치는 것으로 나타났다.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.3
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• pp.388-394
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• 2003

Hydraulic system is difficult to obtain a suitable performance due to the nonlinearity load pressure change and system parameter variation. The requirement of control a1gorithm has been complex in order to satisfy the performance. The adaptive control is a control method which is suggested to achieve the control object under the plant characteristics change. In spite of the case that plant characteristics and the degree of variation are difficult to grasp. the adaptive control could keep the characteristics of closed-loop system generally. In this study. a method of combined generalized minimum variance adaptive control (GMVAC) and output error feedback is proposed, in order to solve the problem of non-minimum phase of plant and the vibration and overshoot in initial response. The control performance according to the variation of characteristics of plant is evaluated by changing the supply pressure. The experimental results show the effectiveness of the proposed scheme.

• Asia Marketing Journal
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• v.11 no.3
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• pp.1-29
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• 2009

The purpose of this study is to develop a service norm construct influencing behavioral intention in a service purchasing situation and investigate how the construct is related with other constructs in the theory of planned action model. Furthermore, a moderating variable, self-monitoring concept, in the model is considered. As a result, the influence of attitude, subjective norm, and perceived control on behavioral intention were all significant. Other consumers' norm was a significant factor affecting behavioral intention. Service provider norm, however, was not significant. In addition, self-monitoring played a moderating role in the model. The implication of this study is that service company or manager should consider service customer compatibility because focal customers are conscious that they face other customer's response.

• The Journal of Korean Association of Computer Education
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• v.14 no.1
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• pp.23-33
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• 2011

The purpose of the study is to investigate the structural relations between variables which give influences on cyber-violence. On the basis of literal materials, those variables as self-control ability, social identity, and norm consciousness are selected as the variables of having influences on cyber-violence, and the analysis is focused on the influence that anonymity, the representative characteristic of Internet, gives them. The validation of the Model is to be done through AMOS 6.0, and the degree of Model validity is to be estimated through the values of ${\chi}^2$, RMSEA, CFI, NNFI. As the result of the analysis, it is found that social identity and norm consciousness are direct causes of cyber-violence. Anonymity does not have any direct relations with it, but it indirectly gives influences on cyber-violence, for it gives some influences on social identity and norm consciousness. That is, anonymity is a cause of weakening social identity and degrading norm consciousness, by which, it is assumed, cyber-violence is triggered.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.22-35
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• 2021

The unprecedented pandemic caused by the COVID-19 has led to a massive global public health campaign to slow the spread of the virus. Thus, this study examines the importance of individual's prevention behavior intention by adapting health belief model(HBM). In addition, we added social variables to understand the prevention behavior better considering the situation in which collective behaviors are important. The online survey results(N=298) showed that higher level of perceived severity, perceived susceptibility, perceived benefits, perceived peril, perceived social norms and lower level of perceived responsibility led to higher prevention behavior intention. Peril was the most influential factor among all the variables. In addition, perceived severity and social norms followed after that. Additional analysis also implied that socio-HBM model we proposed better explained the prevention behavior intention than traditional HBM.