• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.202-209
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• 2007

Vehicle body frame stiffness affects the dynamic and static characteristics. Vehicle frame structural performance is greatly affected by crossmember and joint design. While the structural characteristics of these joints vary widely, there is no known tool currently in use that quickly predicts joint stiffness early in design cycle. This paper presents the joint design factors affecting on low frequency vibration. The joint factors are joint panel thickness, section property, flange width and weld point space. To study the effect on vehicle low frequency vibration, case studies for these factors are performed. And Sensitivity analysis for section property is performed. The result can present design guide for high-stiffness vehicle.

• Korean Management Science Review
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• v.14 no.2
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• pp.113-137
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• 1997

Intranet emerges as a key technology for building enterprise information system. This paper proposes a scenario-based object- oriented technique for designing intranet hypermedia information systems. The method consists of six phases such as domain analysis, object modeling, view design, navigational design, implementation design and construction. Users requirements are analyzed in the form of scenarios by the use fo a responsibility-driven object technology. Object-oriented views are generated from the resulting object model and then used for the subsequent navigational and implementation design. Implementation design phase deals integrating enterprise databases with distributed hypermedia systems by employing Java language. To demonstrate its usefulness, a real-life bank case is illustrated.

• Journal of Navigation and Port Research
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• v.28 no.9
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• pp.791-798
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• 2004

Since world container throughput continues to grow, the main issues facing decision-makers at port container terminals are how to expand the existing container terminals and construct new container terminals. Simulations can be used in the decision making process tools due to its ease and ability to reflect the real world system. The object-oriented approach provides for both reusability and modularity that best fits these requirements. In this paper, the object-oriented approach to modeling and simulating general container terminals is presented. Simulation tools based on Visual C++ provide a user-friendly input and output environment through the use of an object class-library. This paper also presents the case study of a simulation of a real container terminal i. Pusan, Korea

• Communications for Statistical Applications and Methods
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• v.25 no.2
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• pp.185-197
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• 2018

Measuring market fear is an important way of understanding fundamental economic phenomena related to financial crises. There have been several approaches to measure market fear or panic level in a financial market. Recently, herd behavior has gained its popularity as important economic phenomena explaining the fear in the financial market. In this paper, we investigate herd behavior in global stock markets with a focus on intercontinental comparison. While various risk measures are available for the detection of herd behavior in the market, we use the standardized herd behavior index in Dhaene et al. (Insurance: Mathematics and Economics, 50, 357-370, 2012b) and Lee and Ahn (Dependence Modeling, 5, 316-329, 2017) for the comparison of herd behaviors in global stock markets. A global stock market data from Morgan Stanley Capital International is used to study herd behavior especially during periods of financial crises.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.1
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• pp.1-7
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• 1999

In this paper, we use the FDTD method to analyze crosstalk characteristics for high speed pulse signal on MTL(Multi-Transmission Line) in time domain. The FDTD results are compared to the results of SPICE modeling method and the experimental result. The FDTD method has higher accuracy of results than other methods, and it can analyze transmission characteristics of MTL regard to loss of conductor. We analyze crosstalk characteristics for pulse on MTL for lossless and loss case.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.08a
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• pp.77-86
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• 2004

Since world container throughput continues to grow, the main issues facing decision-makers at port container terminals are how to expand the existing container terminals and construct new container terminals. Simulations can be used in the decision making process tools due to its ease and ability to reflect the real world system. The object-oriented approach provides for both reusability and modularity that best fits these requirements. In this paper, the object-oriented approach to modeling and simulating general container terminals is presented. Simulation tools based on Visual C++ provide a user-friendly input and output environment through the use of an object class-library. This paper also presents the case study of a simulation of a real container terminal in Pusan, Korea.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.08a
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• pp.225-230
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• 1998

In this paper, a Kalman filter approach for enhancing speech signals degraded by statistically independent additive nonstationary noise is developed. The autoregressive hidden markov model is used for modeling the statistical characteristics of both the clean speech signal and the nonstationary noise process. In this case, the speech enhancement comprises a weighted sum of conditional mean estimators for the composite states of the models for the speech and noise, where the weights equal to the posterior probabilities of the composite states, given the noisy speech. The conditional mean estimators use a smoothing spproach based on two Kalmean filters with Markovian switching coefficients, where one of the filters propagates in the forward-time direction with one frame. The proposed method is tested against the noisy speech signals degraded by Gaussian colored noise or nonstationary noise at various input signal-to-noise ratios. An app개ximate improvement of 4.7-5.2 dB is SNR is achieved at input SNR 10 and 15 dB. Also, in a comparison of conventional and the proposed methods, an improvement of the about 0.3 dB in SNR is obtained with our proposed method.

• Kyungpook Mathematical Journal
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• v.47 no.3
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• pp.381-392
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• 2007

In 1906, da Rios, a student of Leivi-Civita, wrote a master's thesis modeling the motion of a vortex in a viscous fluid by the motion of a curve propagating in $R^3$, in the direction of its binormal with a speed equal to its curvature. Much later, in 1971 Hasimoto showed the equivalence of this system with the non-linear Schr$\ddot{o}$dinger equation (NLS) $$q_t=i(q_{ss}+\frac{1}{2}{\mid}q{\mid}^2q$$. In this paper, we use the same idea as Terng used in her lecture notes but different technique to extend the above relation to the case of $R^3$, and obtained an analogous equation that $$q_t=i[q_{ss}+(\frac{1}{2}{\mid}q{\mid}^2+1)q]$$.

• Journal of Power System Engineering
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• v.9 no.4
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• pp.194-201
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• 2005

In this paper, we propose an adaptive mechanism based on humoral immune algorithm and neural network identifier technique. It is also applied for an autonomous guided vehicle (AGV) system. When the immune algorithm is applied to the PID controller, there exists the case that the plant is damaged due to the abrupt change of PID parameters since the parameters are almost adjusted randomly. To slove this problem, we use the neural network identifier technique for modeling the plant humoral immune algorithm (HIA) which performs the parameter tuning of the considered model, respectively. Finally, the experimental results for control of steering and speed of AGV system illustrate the validity of the proposed control scheme. Also, these results for the proposed method show that it has better performance than other conventional controller design method such as PID controller.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.343-345
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• 2005

소프트웨어 개발을 위한 분석 및 설계 언어로 UML이 일반화 되어 있다. UML이 갖는 객체지향 개념의 장점으로 인하여 일반 소프트웨어 개발뿐만 아니라 임베디드 소프트웨어 개발에 있어서도 UML의 사용이 증가하고 있다. 특히 UML 모델 중에서 시퀀스 다이어그램은 시스템의 다이나믹스 및 동적 시나리오 표현에 매우 유용하고, 모델링이 직관적이어서 소프트웨어 엔지니어들이 선호하고 있다. 본 연구에서는 시스템 행위를 중심으로 하는 임베디드 소프트웨어 모델링 방법으로 ESUML 방법론을 제시한다. 제시한 ESUML 방법론에서는 Use Case, Class, Interaction overview, Sequence 다이어그램과 Action Language를 이용하여 시스템을 효과적으로 모델링 하도록 하였다.