유전자 알고리즘을 이용한 트러스 및 골조 구조물 최적화

이홍우 서원대학교 응용과학연구소 2003 응용과학연구 Vol.12 No.1

Genetic algorithm is one of the best ways to solve a discrete variable problem. Genetic algorithm tends to thrive in an environment in which the search space is uneven and has many hills and valleys. But, it will be greatly outclassed by more situation specific algorithm in the simpler search spaces and it will be true that genetic algorithm is not always the best choice. In this study, genetic algorithm is compared with the sequential quadratic programming technique. The sequential quadratic programming technique is well known to be one of the most powerful methods for solving the nonlinear constrained optimization problem. In this comparison, three problems are solved by the two method. The first problem is a 3-bar truss design, the second is a 10-bar truss design, and the third is the design of gable structure using H-section steel members. It will obviously show the strong points and weak pints of the genetic algorithm in solving the structural optimization problem.

The Permanent Income Hypothesis : Application to the Study of the Impact of Debt on Household Consumption

Shim,Young,Magrabi,Frances M. 서원대학교 응용과학연구소 1992 응용과학연구 Vol.1 No.1

가계들이 소비자 신용을 이용하고자 하는 경향이 점점 증가하고 있다. 이에 따라 상당한 빚을 짊어지고 있는 가계들이 과연 적절한 소비생활을 할 수 있을 것인가에 관심이 집중되고 있다. 본 연구는 부채가 가계의 소비행동에 어떻게 영향을 주는지 이를 분석하기 위한 개념적 틀을 제안하였다. 본 연구에서 제안된 개념적 틀은 Friedman(1957)의 영구소득가설(The Permanent Income Hypothesis)을 응용한 것이다. 이러한 틀로부터 가계소비와 부채와의 관계에 관한 가설들을 유도하고 통계자료를 통해 이를 검증하였다.

Java Media Framework API를 이용한 방송시스템 구현

강구홍 서원대학교 응용과학연구소 2003 응용과학연구 Vol.12 No.1

Due to the increasing number of real-time multimedia stream type applications like Internet TV, there has been renewed interest in multicast protocols that can reduce the network load greatly compare to the unicast ones. In this paper, we have designed and implemented an IP multicast broadcasting system for these applications especially for On-Air broadcasting and video on demand services. The IP multicast model allows scalable and efficient multi-party communication. However, deployment of IP multicast requires substantial infrastructure modifications for widespread deployment of IGMP and routing protocols as well as complex modifications to IP router's software. Motivated by these programs, we have proposed a limited IP multicasting approach which only supports a local multicasting relying on the multicasting server. We have implemented a client and a server program by Java Media Framework API. In particular, the server program can be running on a web server so that the multicasing server can be implemented on an embeded system and we manage the multicasting server via Internet at remote site. This web server base approach also allows us to manage the media contents separately from the multicasting server system.

모션벡터를 이용한 가상현실 모션베이스 제어방법

이희만 서원대학교 응용과학연구소 2003 응용과학연구 Vol.12 No.1

The purpose of virtual reality research is to develop a virtual reality system which enables to actually experience the virtual reality through the visual sense of human. In this paper, a method of extracting camera motion parameters from any moving pictures is proposed. The motion parameters of camera are obtained from motion vectors of moving pictures. The BMA(Block Matching Algorithm) is utilized to find the motion vectors. It is possible to calculate multiple motion vectors from moving picture, and then camera's motion parameters is obtained by utilizing the relationship between the motion vectors.

여름철 서울시 미새입자(PM_2.5)에 포함된 원소농도 특성

이학성 서원대학교 응용과학연구소 2003 응용과학연구 Vol.12 No.1

Fine particle(dp<2.5㎛) samples were taken in Seoul using an annular denuder system(ADS) with 25-hr sampling period in the summer of 1997. The data set was collected on thirteen different days from 17 July to 11 September 1997. The samples were analyzed using proton induced x-ray emission(PIXE) for the elements of Na, Mg, Al, Si, S, Cl, K, Ca, Ti, Mn, Fe, Zn, and Pb. The magnitude of mean elemental concentrations measured from this study had the following order : S> Si> Na> K> Ca> Fe> Al. Correlation coefficients among Si, Al, Fe, Ca, and K, which may be emitted from soil and paved road dust, were high. Correlation coefficients among Fe, Cu, and Zn were also high, suggesting that these elements may be emitted by fossil fuel, refuse incineration and automobiles. Concentrations of Pb, Cu, Zn, and Mn in Seoul and Taegu were higher than in Chongju. In the case of S, Cl, and Fe, these concentrations in Taegu were higher than those measured in Seoul and Chongju.

유무선 통합의 컨덴츠 개발에 관한 연구

한길성 서원대학교 응용과학연구소 2003 응용과학연구 Vol.12 No.1

The content service of fixed-mobile convergence by communication environment must be changed to the structure of that according to worldwide trends. The new content service of information communication including those of mobile communication, increasing internet and wireless internet, mobile computer are developed by new model in convergent content services containing already wired and wireless contents. The content services of international information communication served multi-content services in convergent network are basically developed network convergence, service convergence and commercial convergence for the content model of fixed-mobile convergence. Therefore, convergent multi-service technology and MPLS/IP are largely accepted MSF in ATM infra-structure. In conclusion, this paper suggested the model of new content services in standard technology of indispensable convergent network and new fixed-mobile convergence fundamentally including mobile and high-speed communication and fixed-mobile convergence.

실시간 주기억장치 데이터베이스 시스템을 위한 질의 최적화

이순조 서원대학교 응용과학연구소 2000 응용과학연구 Vol.9 No.1

This paper proposes query optimization method for real-time main-memory database systems. The proposed method is based on the pruning technique for the memory space and optimization time. For the memory access time, this method is adapted query modification and Lazy Evaluation technique. To evaluate that the proposed query optimization method can improve the system's performance, this method was compared with conventional methods.

이분산 시계열 모형에 관한 연구

이성석 서원대학교 응용과학연구소 2001 응용과학연구 Vol.10 No.1

Recent empirical research relating to many economic data have focused on GARCH-type model. The concept of ARCH model is introduced and some univariate GARCH-type models are considered. And the identification of GARCH-type models using S&P200 data are performed. It is found that AR(2)-GARCH(1,1)-M-t is the good candidate by AIC.

밤 껍질에서 분리 회수한 밤가루를 이용한 밤묵에 관한 연구

조숙자 서원대학교 응용과학연구소 2003 응용과학연구 Vol.12 No.1

This study was to examine the possibility of making use of the edible portion on the inner layer of chestnut, which is produced as wastes in the chestnut processing, into a food resource. As a method, the chestnut powder, which is separated and collected from the inner layer, was used to make chestnut-mooks with 60∼90% of different ratio. Then Quantitative Descriptive Analysis was conducted to examine usability of the chestnut-mook. The chestnut-mooks made by 60∼90% of the chestnut powder was evaluated its flavor, hardness, elasticity, cohesiveness, adhesiveness, chewiness, gumminess, and acceptability; as a result, there was no significant difference between 90% of chestnut-mook and acorn-mook. It would be issue in terms of its price if the quantity of chestnut powder will be raised, because it was collected from the wastes of chestnut layer. Therefore, it is recommended to develop chestnut-mook using over 90% of chestnut powder as local food or traditional food being competitive to acorn-mook.

실시간 이동 트랜잭션의 스케줄링 기법

이순조 서원대학교 응용과학연구소 2001 응용과학연구 Vol.10 No.1

In this paper, we propose a new scheduling method of real-time mobile transaction that has timing constraint by mobility of host. Our scheduling scheme use the queue based on priorities of transactions as a real-time mobile transaction scheduling method for enhancement of predictability and calculate the deadlines of transactions in consideration of constraints of real-time data. This method examines whether transaction can meet deadline or not, and then produces the best execution window for scheduling. Therefore, the proposed method prevents transaction restarts due to violation of constraint of real-time data, and maximizes the sum of the priorities of transactions that satisfy its deadline. The performance evaluation, is a comparison of traditional methods, shows that our scheduling method is improved from 20% to 30%