• International Journal of Control, Automation, and Systems
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• 제6권4호
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• pp.571-582
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• 2008

This paper analyzes global convergence of the univariate dynamic encoding algorithm for searches (uDEAS) and provides an application result to function optimization. uDEAS is a more advanced optimization method than its predecessor in terms of the number of neighborhood points. This improvement should be validated through mathematical analysis for further research and application. Since uDEAS can be categorized into the generating set search method also established recently, the global convergence property of uDEAS is proved in the context of the direct search method. To show the strong performance of uDEAS, the global minima of four 30 dimensional benchmark functions are attempted to be located by uDEAS and the other direct search methods. The proof of global convergence and the successful optimization result guarantee that uDEAS is a reliable and effective global optimization method.

• 한국군사과학기술학회지
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• 제26권3호
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• pp.273-280
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• 2023

Recently electronic safety and arming device(ESAD) has attracted increasing attention due to its design flexibility. However, ESAD can be armed unintentionally due to a malfunction of an external device or interface. Thus ESAD needs an internally generated arming signal independent from the external device. In this paper, a new sensor-hybrid ESAD(SHESAD) with a flight environment sensing function for generating arming signal internally is proposed and a sled test based method is also suggested for evaluating its functions. Through the test results, the operability of the flight environment sensing function was confirmed. Also, it is shown that the proposed test method is suitable for verification of ESAD with the flight environment sensing function.

• 한국CDE학회논문집
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• 제12권3호
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• pp.220-232
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• 2007

Current geometric modeling and analysis are commonly based on B-Rep modeling and a finite elements method respectively. Furthermore, it is difficult to represent an object whose material property is heterogeneous using the B-Rep method because the B-Rep is basically used for homogeneous models. In addition, meshes are required to analyze a property of a model when the finite elements method is applied. However, the process of generating meshes from B-Rep is cumbersome and sometimes difficult especially when the model is deformed as time goes by because the topology of deforming meshes are changed. To overcome those problems in modeling and analysis including homogeneous and heterogeneous materials, we suggest a unified modeling and analysis method based on implicit representation of the model using R-function which is suggested by Rvachev. For implicit modeling of an object a distance field is approximated and blended for a complex object. Using the implicit function mesh-free analysis is possible where meshes are not necessary. Generally mesh-free analysis requires heavy computational cost compared to a finite elements method. To improve the computing time of function evaluation, we utilize GPU programming. Finally, we give an example of a simple pipe design problem and show modeling and analysis process using our unified modeling and analysis method.

• 한국게임학회 논문지
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• 제8권4호
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• pp.75-85
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• 2008

UCC(User Created Contents) 사이트가 활성화되면서 제작 가능한 콘텐츠 종류가 다양해졌다. 제작 가능한 콘텐츠 중에서 UCG(User Created Game)는 사용자가 직접 제작하고 공유하는 게임이다. UCG의 제작 방법은 사용자의 숙련도에 따라서 두 가지로 분류해 볼 수 있다. 첫 번째, 저작도구를 사용하는 방법은 게임 제작에 익숙하지 않은 초보 사용자에게 적합하지만 사용방법이 쉬워지면서 기능이 제약적이다. 두 번째, 프로그램 언어를 이용한 개발은 게임 제작에 익숙한 고급 사용자에게 적합하지만 개발기간이 길어진다. 이 논문에서는 스크립트를 사용해서 초보 사용자에게 적합한 저작도구의 기능을 확장하는 방법을 제안한다. 그리고 제안한 저작도구는 프로그램 소스를 생성하기 때문에 고급 사용자는 제공하지 않는 기능만 추가 구현해서 개발 기간을 단축한다. 제안한 방법의 UCG 제작 과정을 검증하기 위해서 게임 제작에 필요한 GUI, 스크립트 생성 기능과 프로그램 소스 생성 기능을 포함하는 프레임워크를 설계한다. 그리고 설계한 게임 저작도구를 구현해서 개발된 게임 제작 사례를 보임으로써 본 연구에서 제안하는 방법을 소개한다.

• 산업경영시스템학회지
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• 제25권5호
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• pp.31-38
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• 2002

In this paper, we model a two-server queueing system with priority, to which we put a restriction on the number of servers for each customer class. customers are divided into two different classes. Class 1 customers have non-preemptive priority over class 2 customers. They are served by both servers when available but class 2 customers are served only by a designated server. We use a method of generating function depending on the state of servers. We find the generating function of the number of customers in queue, server utilization, mean queue length and mean waiting time for each class of customers.

• 대한기계학회논문집
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• 제12권3호
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• pp.561-565
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• 1988

본 연구에서는 제어함수를 수식으로부터 유도하여 자동적인 격자간격제어가 가능한 "근사직교 경계고정곡선좌표계"를 생성하는 새로운 방법을 제시하여 2차원영역 에 대한 그 적용을 논의하고자 한다. 논의하고자 한다.

• 한국해안해양공학회지
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• 제17권1호
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• pp.21-31
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• 2005

본 연구에서 Nwogu(1993)의 확장형 Boussinesq 방정식에 대하여 한 격자의 조파 띠에 균일하게 분포하는 원천함수를 유도하였다. 원천함수를 포함하는 확장형 Boussinesq 방정식에 부분단계분리법을 적용하여, 에너지 전송속도를 사용하는 선 조파기법의 타당성을 해석적으로 증명하였다. 수평공간 1차원의 경우 선형파 뿐만 아니라 비선형파를 조파하여 원천함수기법에 의한 내부조파기법의 정확성을 검증하였다. 또한 원천함수기법에 의한 수치 결과가 선 내부조파기법에 의한 수치 결과와 동일함을 확인하였다.

• 한국정밀공학회지
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• 제18권4호
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• pp.55-63
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• 2001

This paper describes a methodology of product function deployment for understanding product functions and generating systematic functional relation charts. The product function deployment is based on the designer's understanding of product functions. The method involves following steps: 1) definition of product primary function and flows of energy, material, and information, 2) construction of a product tree using key parts, 3) definition of functions and interactions of the functional units, 4) construction of 'from-to' relation matrices, 5) grouping of the parts, and 6) construction of functional relation charts. With this approach, functional relation charts can be generated such that complex product functions are easily understood. The functional relation chart of a refrigerator is generated as an example.

• 응용통계연구
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• 제31권6호
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• pp.761-769
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• 2018

통계학 연구에 모의실험이 중요하게 쓰이며 중도절단자료를 다루는 생존분석에서도 마찬가지다. 생존분석에서 Cox 모형이 널리 쓰이는데, Cox 모형을 따르는 중도절단자료를 생성하는 방법에 대해 살펴보았다. Bender 등 (Statistics in Medicine, 24, 1713-1723, 2005)은 생존시간을 생성하는 모수적 방법을 제시하였으나 생존시간뿐만 아니라 중도절단시간도 생성해야 중도절단자료를 얻게 된다. 중도절단자료를 생성하기 위한 모수적 방법과 함께 비모수적 방법도 제시하였으며 실제 자료에도 적용해 보았다.

• 설비공학논문집
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• 제3권2호
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• pp.103-113
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• 1991

This paper presents a method for estimating the noise source contribution of a pulse combustion burner in a multiple input system where the input sources may be coherent each other. By coherence function method, it is found that the biggest part of the noise source in the pulse combustion burner is generated by the part of the combustion chamber. This analysis is modeled as three input / single output system because the noise generating mechanism of the pulse combustion burner is very complicated. The coherence function method is proved to be useful tool for the identification of noise source. The overall levels of the radiated source pressure by coherence function method are compared with those measured and calculated by the frequency response function approach. The experimental results have shown a good agreement with the results calculated by the coherence function method when the input sources are coherent strongly each other. The estimation of shield effect by FRF method indicates that significant reduction can be achieved in sound radiation if only transmission path generated by the part of combustion chamber is acoustically shield.