• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 B
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• pp.449-451
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• 1997

In this paper, A continuous control reaching law for variable structure control is proposed to reduce the chattering and improve the robustness properties in the presence of matched uncertainly.

• 응용통계연구
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• 제19권1호
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• pp.149-161
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• 2006

CART로 대표되는 의사결정나무의 알고리즘에서 가장 중요한 요소는 분리변수의 선택방법이다. 대부분의 알고리즘은 변수의 형태가 연속형인지, 혹은 명목형(nominal)인지에 따라 별개의 변수선택방법을 적용한다. 하지만 변수의 형태가 순서형(ordinal)인 경우에는 그 변수를 연속형으로 취급하여 연속형 변수선택방법을 적용하는 것이 대부분이다. 이것은 CART와 같은 Greedy탐색을 이용하는 방법에는 문제점이 발생하지 않는다. 하지만 Greedy탐색의 약점을 보완하기 위해 통계이론을 이용하여 개발된 최근의 방법들에는 최선의 대처방법이 아니다. 따라서 본 연구에서는 의사결정 나무에서 분리변수를 선택하는데 있어서 비모수적 접근 방법인 Clamor-von Mises 검정을 이용한 방법을 순서형 변수에 사용하는 것을 제안하고, CART, C4.5, QUEST, CRUISE등 기존 알고리즘과 본 연구에서 제안하는 방법의 순서형 변수 선택력을 비교하였다. 모의실험의 결과, Clamor-von Mises 검정을 이용한 변수선택방법은 순서형 변수의 분류력을 기존 방법들에 비해 더 정확히 예측하는 좋은 성과를 보여주었다.

• 대한수학회지
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• 제51권3호
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• pp.527-543
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• 2014

The theory of random variable structures was first studied by Ben Yaacov in [2]. Ben Yaacov's axiomatization of the theory of random variable structures used an early result on the completeness theorem for Lukasiewicz's [0, 1]-valued propositional logic. In this paper, we give an elementary approach to axiomatizing the theory of random variable structures. Only well-known results from probability theory are required here.

• 전자공학회논문지
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• 제52권7호
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• pp.127-134
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• 2015

본 연구에서는 다입출력 불확실 선형 플랜트를 위한 포화함수에 의한 연속 슬라이딩 면 변환 가변 구조 시스템이 주어진다. 이론적으로 불연속 슬라이딩 면 변환 가변구조 시스템을 제안한다. 사전에 결정된 슬라이딩 면 위에 슬라이딩 모드의 다입출력 존재 조건과 함께 페루프 지수 안정성에 대해 검토한다. 실제 응용을 위하여 포화 함수에 의하여 불연속 가변구조 시스템의 연속 근사화를 이룬다. 실제적인 관점에서 가변 구조 시스템의 내부 특성인 제어입력의 불연속성을 많이 개선한다, 설계 예와 시뮬레이션 연구를 통하여 제안된 연속 변환 가변구조 시스템 제어기의 유용성을 입증한다.

• 한국정보시스템학회지:정보시스템연구
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• 제31권1호
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• pp.1-24
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• 2022

Purpose The purpose of this study is to investigate the factors that affect the user satisfaction and continuous use intention of the improved ATCIS in the Korean Army. Design/methodology/approach Based on the various theories in relation to IT continuance, user satisfaction was identified as the main factor with regard to the continuous use intention of the improved ATCIS. In addition, computer self-efficacy, education-training, and system quality were hypothesized as antecedent variables to user satisfaction, and information security stress was set as a moderating variable for these relationships. Findings Survey results show that computer self-efficacy, education and training, and system quality had a positive effect on user satisfaction, and information security stress was found to moderate these relationships. The effects of computer self-efficacy and education-training on user satisfaction were higher in the group with low information security stress. However, the relationship between system quality and user satisfaction was higher in the group with high information security stress. User satisfaction is found to have a positive effect on the continuous use intention even with habit considered as a control variable.

• 데이타베이스연구회지:데이타베이스연구
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• 제34권3호
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• pp.159-169
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• 2018

연속형 변수의 이산화(Discretization)는 양적 변수(Quantitative variable)를 질적 변수(Qualitative variable)로 변형시켜 데이터 마이닝(Data mining) 기법 등 다양한 알고리즘의 성능을 향상시키는데 사용 목적이 있다. 데이터에 적절한 이산화 기법을 사용한다면 분류 알고리즘에 대해 더 좋은 성능뿐 아니라 간결한 결과 해석, 속도 향상까지 기대할 수 있다. 현재까지 다양한 이산화 기법들이 연구되었으며, 현재도 이산화와 관련한 연구에 수요가 많다. 본 논문은 데이터의 클래스에 대한 연속형 변수 값의 분포를 고려하여, Wasserstein 거리를 이용해 분할점을 자동 설정하는 이산화 기법을 제안한다. 본 논문에서 제안하는 기법과 우수함이 입증된 기존의 이산화 기법에 대해 성능비교를 통해 제안 기법의 우수성을 보인다.

• Journal of Information Technology Applications and Management
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• 제28권6호
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• pp.1-21
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• 2021

This study is about Augmented Reality Game (AR Game) applied to Pokemon Go, which has recently been a sensational game. We focused on and analyzed the intention for continuous use as a dependent variable. We made hypotheses through previous studies and used spatial presence, perceived interactivity, perceived pleasure, and sickness as independent variables. Immersion was set up as a mediating variable. We conducted the study using 198 data, which people who experienced AR games responded. The results were as follows. First, spatial presence and perceived pleasure were found to have a significant effect on immersion, as in previous studies. Second, the relationship between sickness and immersion, which were shown to have a negative relationship in previous studies, we found that variables had a positive relationship unlike previous studies and rejected the hypothesis. Third, perceived interactivity, which is one of the crucial variables to affect the intention for continuous use, we found not to have a significant relationship among perceived interactivity, immersion, and the intention for continuous use. This result is opposite from previous studies, and further research on this issue is expected. We conducted this study with an individual user's view on immersion and the intention for continuous use rather than focusing on technical or political topics. Besides, this study has a significance that drew different results from previous studies and explored people who relish AR games with the characteristics of personal variables.

• Communications for Statistical Applications and Methods
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• 제12권3호
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• pp.659-672
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• 2005

This paper evaluates discretization of continuous variables to select relevant variables for supervised learning using mutual information. Three discretization methods, MDL, Histogram and 4-Intervals are considered. The process of discretization and variable subset selection is evaluated according to the classification accuracies with the 6 real data sets of UCI databases. Results show that 4-Interval discretization method based on quantiles, is robust and efficient for variable selection process. We also visually evaluate the appropriateness of the selected subset of variables.

• 대한전자공학회논문지
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• 제25권3호
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• pp.262-268
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• 1988

In this paper conditions are derived, which ensure the existence of a quasi-sliding mode on the control switching hyperplane in discrete variable structure control systems and also remove the reaching phase problem observed in continuous-time variable structure systems. In addition, a discrete variable structure tracking controller which has adaptive properties is devised based on these results. This controller has useful properties, such as small sensitivity to the variation of plant parameters and to disturbances and its performing speed is fast compared to that of other adaptive controller.

• 대한수학회보
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• 제58권2호
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• pp.365-384
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• 2021

Let A be an expansive dilation on ℝn, and p(·) : ℝn → (0, ∞) be a variable exponent function satisfying the globally log-Hölder continuous condition. Let Hp(·)A (ℝn) be the variable anisotropic Hardy space defined via the non-tangential grand maximal function. In this paper, the author obtains the boundedness of anisotropic convolutional ��-type Calderón-Zygmund operators from Hp(·)A (ℝn) to Lp(·) (ℝn) or from Hp(·)A (ℝn) to itself. In addition, the author also obtains the duality between Hp(·)A (ℝn) and the anisotropic Campanato spaces with variable exponents.