• ETRI Journal
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• 제24권1호
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• pp.43-55
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• 2002

This paper proposes a flow-based admission control algorithm through an Asynchronous Transfer Mode (ATM) based Multi-Protocol Label Switching (MPLS) network for multiple service class environments of Integrated Service (IntServ) and Differentiated Service (DiffServ). We propose the Integrated Packet Scheduler to accommodate IntServ and Best Effort traffic through the DiffServ-aware MPLS core network. The numerical results of the proposed algorithm achieve reliable delay-bounded Quality of Service (QoS) performance and reduce the blocking probability of high priority service in the DiffServ model. We show the performance behaviors of IntServ traffic negotiated by end users when their packets are delivered through the DiffServ-aware MPLS core network. We also show that ATM shortcut connections are well tuned with guaranteed QoS service. We validate the proposed method by numerical analysis of its performance in such areas as throughput, end-to-end delay and path utilization.

• Management Science and Financial Engineering
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• 제16권3호
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• pp.1-20
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• 2010

In this paper, the impact of various system parameters such as the parameters of actual demand process, the review periods and the lead times, under each combination of inventory policies and information sharing, on the long run average inventory cost per period incurred at each participant in a supply chain, is considered. For this purpose, numerical studies are conducted, from which some valuable information as to how sensitive our long run average inventory cost per period are as the model parameters change is gleaned, from which, in turn, some managerial insights are gleaned in order for industry practitioners to perform better in supply chain management.

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

• International journal of advanced smart convergence
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• 제2권1호
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• pp.18-20
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• 2013

The significance, is to introduce a novel way to employ the improved Runge-Kutta fifth order five stage method, here after called as Modified IRK(5,5) method, for system of second order robot arm problem and variations in angles at the joints in which parameters governing with two degrees of freedom which requires lesser number of function evaluations per time step as compared to the existing ones, in order to save time and spaceAn ultimate aim of this present paper is to solve application problem such as robot arm and initial value problems by applying Runge-Kutta fifth order five stage numerical techniques. The calculated output for robot arm coincides with exact solution which is found to be better, suitable and feasible for solving real time problems.

• 정보기술과데이타베이스저널
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• 제3권1호
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• pp.97-108
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• 1996

In this paper we obtain several function defined on finite partially ordered sets(posets) which may indicate constraints of comparability on sets of teams(tasks, etc.) for which evaluation is computationally simple, a relatively rare condition in graph-based algorithms. Using these functions a set of numerical coefficients and associated distributions obtained from a computer simulation of certain families of random graphs is determined. From this information estimates may be made as to the actual linearity of complicated posets. Applications of these ideas is to all areas where obtaining rankings from partial information in rational ways is relevant as in, e.g., team_, scaling_, and scheduling theory as well as in theoretical computer science. Theoretical consideration of special and desirable properties of various functions is provided permitting judgment concerning sensitivity of these functions to changes in parameters describing (finite) posets.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.53-55
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• 2013

마이크로파 소자 및 각종 전파환경 해석을 위해서는 MoM, TLM, FEM, BEM 등의 다양한 전자계해석 수법을 이용할 수 있다. 본 연구에서는 자바 기반 병렬화 기법을 토대로 구현된 수치 시뮬레이터를 개발하고 그 성능을 평가하였다.

• International Journal of Precision Engineering and Manufacturing
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• 제9권2호
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• pp.8-10
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• 2008

Chemical mechanical polishing (CMP) is a very precise planarization technique where a wafer is polished by a slurry-coated pad. A slurry is dropped on the rotating pad surface and is supplied between the wafer and the pad. This research aims at reducing the slurry consumption and removing waste particles quickly from the wafer. To study the roles of grooves, slurry flows were simulated using the volume of fluid method (two-phase model for air and slurry) for pads with no grooves, and for pads with circular grooves.

• Current Optics and Photonics
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• 제7권1호
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• pp.54-64
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• 2023

This paper proposes dynamic viewing-zone switching for a binocular holographic three-dimensional display with low interpupil crosstalk and an extended eye-motion box. The optimal pupil geometry for reducing interpupil crosstalk is designed. It is shown that the eye-motion box can be extended by exploiting signal replication in the higher-order viewing zone. Design principles and numerical simulations for verification of the binocular holographic head-up display are presented.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 춘계학술발표대회 논문집
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• pp.145-149
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• 2009

High-resolution atmospheric numerical system was set up to simulate the motion of the atmosphere and to produce the wind map on land. The results of several simulations were improved compare to the past system, because of using the fine geographical data, such as terrain height and land-use data, and the meteorological data assimilation. To estimate surface maximum wind speed when a typhoon is expected to strike the Korea peninsula, wind information at the upper level atmosphere was applied. Using 700hPa data, wind speed at the height of 300m was estimated, and surface wind speed was estimated finally considering surface roughness length. This study used formula from other countries and estimated RMW but RMW estimation formula apt to Korea should be developed for future.

• 기술혁신연구
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• 제9권1호
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• pp.149-165
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• 2001

This paper analyses characteristics of the numerical controller industry in market formation and the flow of information between users and producers and the characteristic of knowledge base of the industry and discuses the difficulties derived, from the characteristics, in accumulation of technological capability. In market formation between users and producers, the multi-layered market is not favorable to domestic producers in that lower end market is not large enough to provide cradle market to them which produce inferior quality and lower price than imported products. The credibility of the performance of a product is different to prove until a critical mass of products are sold. Therefore gaining market share is deterred by unproven credibility of the performance of the product. The flow of information between users and producers is limited. The flow of information on users environment through mass market to producers is essential for improving credibility of a product. The nature of knowledge base is tacit and the means of knowledge transmission is limited. Technological licensing and reverse engineering, which have been conventional means of knowledge transmission, are not useful in the numerical controller industry. These characteristics provide conditions of vicious circle in accumulation of technological capability of the numerical controller industry. This paper argues that these characteristics of the industry challenge existing approach to R&D management and framework of science and technology policy.