• Journal of the Institute of Convergence Signal Processing
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• v.3 no.3
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• pp.21-26
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• 2002

This paper presents the new approach of identifying human emotional states such as anger, happiness, normal, sadness, or surprise. This is accomplished by using discrete duration continuous hidden Markov models(DDCHMM). For this, the emotional feature parameters are first defined from input speech signals. In this study, we used prosodic parameters such as pitch signals, energy, and their each derivative, which were then trained by HMM for recognition. Speaker adapted emotional models based on maximum a posteriori(MAP) estimation were also considered for speaker adaptation. As results, the simulation performance showed that the recognition rates of vocal emotion gradually increased with an increase of adaptation sample number.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.11
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• pp.53-67
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• 1998

This paper suggests a method designing the TSK fuzzy controller based on the TSK fuzzy model, which guarantees the stability of the closed loop system and makes the response of the closed loop system to be a desired one. This paper deals with the general type of TSK fuzzy model of which consequents are affine equations having a constant term. The TSK fuzzy controller suggested in this paper is designed by using the pole placement which developed for the linear systems and makes the closed loop system have the same behavior as a desired linear system. A reference input can be introduced to the suggested TSK fuzzy controller and an integral action also can be introduced. Simulation results reveal that the suggested methods are practically feasible. This paper deals with both the continuous systems and the discrete systems.

• Journal of the Korean Institute of Intelligent Systems
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• v.8 no.4
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• pp.53-61
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• 1998

This paper describes the stability analysis of TSK (Takagi-Sugeno-Kang) fuzzy systems which can represent a large class of nonlinear systems with good accuracy. A TSK fuzzy model consists of TSK fuzzy rules and the consequent of each fuzzy rule is a linear input-output equation with a constant term. There may exist equilibrium points more than one in the TSK fuzzy model and each equilibrium point rnay also have different nature of stability. The local stability of an equilibrium point is determined by eigenvalues of the Jacobian matrix of the linearized TSK fuzzy model around the equilibrium point. Stability of both the continuous-time and the discrete-time systems is analyzed in this paper.

• Journal of KIISE:Software and Applications
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• v.30 no.7_8
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• pp.713-718
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• 2003

The CONDENSATION (Conditional Density Propagation) algorithm has a robust tracking performance and suitability for real-time implementation. However, the CONDENSATION tracker has some difficulties with real-time implementation for multiple people tracking since it requires very complicated shape modeling and a large number of samples for precise tracking performance. Further, it shows a poor tracking performance in the case of close or partially occluded people. To overcome these difficulties, we present three improvements: First, we construct effective templates of people´s shapes using the SOM (Self-Organizing Map). Second, we take the discrete HMM (Hidden Markov Modeling) for an accurate dynamical model of the people´s shape transition. Third, we use the competition rule to separate close or partially occluded people effectively. Simulation results shows that the proposed CONDENSATION algorithm can achieve robust and real-time tracking in the image sequences of a crowd of people.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.2
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• pp.115-122
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• 2000

In design of a digital current controller for a 3cP PWM converter, its conventional model is used in obtaining i its discretized version. But, it has errors since the characteristics of SVPWM and time delay are not taken i into consideration. In this paper, the new reference frame model of a 3c~ PWJVI converter is proposed C considering these problems. Also, the direct digital current controller based on this model is designed without a any extra algolithm. A simple tuning algorithm for the proposed current controller is given to compensate the i inductaηce mismatch problem. Then simulation and experimental results show the validity of the algolithm.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2016.11a
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• pp.433-434
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• 2016

본 논문에서는 최근 발생하는 다양한 기후변화 문제에 따라 복합적인 침수가 많이 발생한다고 판단하여 침수의 복합원인을 찾아내고 그에 따른 값을 모의하게 된다. 침수의 요인으로는 크게 제내지 배수불량에 따른 내수침수와 하천의 수위가 높아져 월류하게 되는 외수범람이 존재한다. 기존의 연구들은 내수침수와 외수범람을 독립적으로 침수해석하여 단순한 선형합의 형태로 내외수 침수를 산정하였으나, 본 연구에서는 2차원 동수역학모형인 HDM-2D 모델을 이용하여 내수침수와 외수범람의 독립적인 모의는 물론 복합적인 모의를 하여 비교, 분석 하고자 한다. HDM-2D모델은 3가지 모형으로 구성된다. 첫째는 2차원 천수방석식과 유한요소법 이산화로 구성된 흐름해석 모형이다. 둘째는 ERG (Exponentially Growth Rate) 기법에 의하여 생성/소멸 기작이 적용된 내수침수 해석 모듈이다. 마지막은 Petrov 안정화 기법에 의한 충격파 전달 해석이 적용되며, Flux-blocking 알고리즘으로 마름/젖음을 안정적 모의할 수 있는 외수범람 해석 모듈이다. 이러한 모델을 통해 내수침수와 외수범람을 독립적, 복합적으로 모의를 진행한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.361-361
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• 2020

우리나라의 경우 강수량이 지역별로 편중되면서 국지적 가뭄이 발생하고, 지형적 특성으로 상습가뭄지역 피해가 확대되고 있다. 더불어 강수의 시기별 편차가 커지면서 봄 가뭄 증가 및 장기 기후변화 시나리오도 가뭄 발생 가능성 증가를 전망하고 있다. 그러나 우리나라의 경우 가뭄대응 대책 마련시 선제적인 가뭄대응 대책 마련보다, 사후복구·단기대책을 중심으로 가뭄대응능력을 추진하고 있어 예방중심의 가뭄대응능력의 한계점을 지니고 있다. 본 연구에서는 선제적 예방 중심의 가뭄대응 전략을 위해 물순환 모델을 기반으로 수원별 가뭄대응능력을 평가하고, 지역별로 산정된 용수공급가능일수를 기반으로 수문학적 가뭄취약지도를 작성하는 것을 목적으로 한다. 이때 용수공급가능일수는 가뭄시나리오(20년, 30년, 50년 등)를 설정하여 시나리오별 공급가능일수를 평가하여 시공간적 가뭄취약성 분석이 가능한 모형으로 확장하였다. 수문학적 가뭄취약지도의 경우 정책결정자, 업무사용자 등 효율적 정보 제공이 가능할 것으로 판단되며, 지역별로 현안사항 도출 및 개선방안을 위한 기초자료로 활용 될 수 있을 것으로 기대된다.

• The Korean Journal of Applied Statistics
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• v.25 no.2
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• pp.279-291
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• 2012

When fitting a Cox proportional hazards model with missing covariates, it is inefficient to exclude observations with missing values in the analysis. Furthermore, if the missing-data mechanism is not Missing Completely At Random(MCAR), it may lead to biased parameter estimation. Many approaches have been suggested to handle the Cox proportional hazards model when covariates are sometimes missing, but they are based on the selection model. This paper suggest an approach to handle Cox proportional hazards model with missing covariates by using the pattern-mixture model (Little, 1993). The pattern-mixture model is expressed by the joint distribution of survival time and the missing-data mechanism. In the pattern-mixture model, many models can be considered by setting up various restrictions, and different results under various restrictions indicate the sensitivity of the model due to missing covariates. A simulation study was conducted to show the sensitivity of parameter estimation under different restrictions in a pattern-mixture model. The proposed approach was also applied to mouse leukemia data.

• The Journal of Korean Association of Computer Education
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• v.17 no.6
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• pp.103-113
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• 2014

This study designed and implemented a query model for consecutive analyses of dynamic multivariate graph data. First, the query model consists of two procedures; setting the discriminant function, and determining an alteration method. Second, the query model was implemented as a query system that consists of a query panel, a graph visualization panel, and a property panel. A Node-Link Diagram and the Force-Directed Graph Drawing algorithm were used for the visualization of the graph. The results of the queries are visually presented through the graph visualization panel. Finally, this study used the data of worldwide import & export data of small arms to verify our model. The significance of this research is in the fact that, through the model which is able to conduct consecutive analyses on dynamic graph data, it helps overcome the limitations of previous models which can only perform discrete analysis on dynamic data. This research is expected to contribute to future studies such as online decision making and complex network analysis, that use dynamic graph models.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.6
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• pp.667-672
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• 2003

In this paper, we propose a systematic method for intelligent digital redesign of a fuzzy-model-based controller for continuous-time nonlinear dynamical systems which may also contain uncertainties. The continuous-time uncertain TS fuzzy model is first constructed to represent the uncertain nonlinear systems. An extended parallel distributed compensation(EPDC) technique is then used to design a fuzzy-model-based controller for both stabilization and tracking. The designed continuous-time controller is then converted to an equivalent discrete-time controller by using an integrated intelligent digital redesign method. This new design technique provides a systematic and effective framework for integration of the fuzzy-model-based control theory and the advanced digital redesign technique for nonlinear dynamical systems with uncertainties. Finally, The single link flexible-joint robot arm is used as an illustrative example to show the effectiveness and the feasibility of the developed design method.