• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 1998년도 가을 학술발표회논문집
• /
• pp.280-282
• /
• 1998

Communications, data storage or computation by manipulating the optical signals have the strong advantages over the traditional electronic circuits in regard to the data handling speed and capacity. Effective manipulation of the optical signals, however, requires materials of large nonlinear coefficients and of fast response time. Polymeric materials are one of the promising materials to meet the requirements for nonlinear optical (NLO) materials. (omitted)

• 한국항만경제학회지
• /
• 제19권2호
• /
• pp.55-67
• /
• 2003

The purpose of this study is to estimate and forecast the marine trading volumes based on the structural model. We employ GPH cointegration test since the structural model must be stationary to get the accurate predicted values. The empirical results show that our model is stationary. This paper also applies variance decompositions and impulse-response functions to the structural model composed of exchange rate, domestic industrial activity, and world business. The results indicate that while both loading and unloading volumes respond positively to the shocks in income and then decay very slowly, their responses are different to the shocks in exchange tate.

• 한국해안해양공학회:학술대회논문집
• /
• 한국해안해양공학회 1993년도 정기학술강연회 발표논문 초록집
• /
• pp.9-13
• /
• 1993

Modernization of a port requires a considerable port facility expansion through grading up the cargo handling efficiency, increasing water depth of channels and basins to accomodate Large ships, etc. In many ports in the world, the needs of bigger ship calls in excess of conventional capacity of channels and basins demand for capital dredging as well as maintenance dredging resulting from siltation, and those activities are incurring heavy annual expenditure of the ports. (omitted)

• Industrial Engineering and Management Systems
• /
• 제3권2호
• /
• pp.116-122
• /
• 2004

This paper presents a process plan selection model with multiple objectives. The process plans for all parts should be selected under multiple objective environment as follows: (1) minimizing the sum of machine processing and material handling time of all the parts considering realistic shop factors such as production volume, processing time, machine capacity, and capacity of transfer device. (2) balancing the load between machines. A multiple objective mathematical model is proposed and an evolutionary algorithm with the adaptive recombination strategy is developed to solve the model. To illustrate the efficiency of proposed approach, numerical examples are presented. The proposed approach is found to be effective in offering a set of satisfactory Pareto solutions within a satisfactory CPU time in a multiple objective environment.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제5권11호
• /
• pp.2035-2051
• /
• 2011

Theoretical Bit Error Rate (BER) and channel capacity analysis are always of great interest to the designers of wireless communication systems. At the center of such analyses people are often encountered with a high-dimensional multiple integrals with quite complex integrands. Conventional Gaussian quadrature is inefficient in handling problems like this, as it tends to entail tremendous computational overhead, and the principal order of its error term increase rapidly with the dimension of the integral. In this paper, we propose a new approach to calculate complex multi-fold integrals based on the number theory. In contrast to Gaussian quadrature, the proposed approach requires less computational effort, and the principal order of its error term is independent of the dimension. The effectiveness of the number theory based approach is examined in BER and capacity analyses for practical systems. In particular, the results generated by numerical computation turn out in good match with that of Monte-Carlo simulations.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2001년도 ICCAS
• /
• pp.74.4-74
• /
• 2001

In this paper, we propose a row warehouse type container yard (WTCY) which deal with the excess of port´s container capacity in 2004 instead of using the Yangsan inland container depot (ICD) in Pusan container terminals. Because the off dock container yard (ODCY) which located in Pusan port around exceeds the port´s capacity in 2004, the Yansan ICD will be used for handling an overflowed amount of containers. But there are need an amount of extra expense includes social overhead capital (SOC) to transports containers to Yangsan ICD. To overcome this problem, a WTCY which can be handled the container in each floors is proposed. The proposed WTCY can be located in container terminal ...

• 한국통신학회논문지
• /
• 제19권7호
• /
• pp.1335-1345
• /
• 1994

대용량 교환시스템인 TDX-10의 내부통신망의 성능을 분석하였다. 내부통신망의 시뮬레이션은 SLAM II의 이산사건모델을 이용하여 개발하였다. 시뮬레이션의 결과로 각 노드에서의 최대버퍼길이와 평균대기시간 그리고 D버스의 이용율을 구하였다. 또한 링크속도를 고려한 내부통신망의 최대호처리용량을 구하였다.

• 경영과학
• /
• 제10권1호
• /
• pp.127-137
• /
• 1993

The blocking probabilities of nx64Kb/s multi-slot calls are generally much higher than that of single slot calls. In order to improve these blocking probabilities of multi-slot calls, we propose a scheme which searches the different numbers of time slots for different types of calls. We analyze the performance of our scheme in a double-buffered time-space-time switching network which accommodates multi-slot calls as well as single-slot calls. The proposed method yields the reduced blocking probabilities, the increased traffic handling capacity and teh reduced CPU processing load, compared with those of the conventional methods.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
• /
• pp.10-14
• /
• 2004

When providing flexible data transmission for future CDMA(Code Division Multiple Access) cellular networks, problems arise in two aspects: transmission rate. This paper has proposed an approach to maximize the cellular network capacity by combining the genetic transmission rate allocation and a rapid power control algorithm. We present a genetic chromosome representation to express call drop numbers and transmission rate to control mobile's transmission power levels while handling their flexible transmission rates. We suggest a rapid power control algorithm, which is based on optimal control theory and Steffenson acceleration technique comparing with the existing algorithms. Computer simulation results showed effectiveness and efficiency of the proposed algorithm Conclusively, our proposed scheme showed high potential for increasing the cellular network capacity and it can be the fundamental basis of future research.

• 한국해양공학회지
• /
• 제18권6호
• /
• pp.101-107
• /
• 2004

In this paper, the design criteria of future container crane for megaships are investigated. The current loading/unloading capacity of a typical container crane, roughly 30 moves/hr, is too law to meet the requirements of future super containerships, which are expected over 15,000 TEU. After examining the transition of containerships through the years and studying the research trend in developed countries, the specifications of the container crane that can Meet a 15,000 TEU containership are proposed. The structure, trolley and hoist mechanism, outreach, backreach, capacity, speeds, durability, and stability of the future container crane are described.