• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.4
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• pp.473-484
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• 1998

The current interconnection charge regimes is based in fully distributed costing method. Basically this method doesn't give the incument carrier the incentive to promote efficient business operations. In this paper, 1 suggest the adoption of price cap regulation to interconnection charge as incentive schemes and review important considerations in its applications. Additionally I suggest the basic structure of the network costing model for applications of incremental costing method.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.224-226
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• 2005

Grid computing enables the fundamental computing shift from a localized resource computing model to a fully-distributed virtual organization with shared resources. In the grid computing environment, grid users usually get access rights by mapping their credential to local account. The mapped total account is temporally belongs to grid user. So, data on the secondary storage, which is produced by grid operation, can increase the load of system administration or can issue grid user's privacy. In this paper, we design a data management system for grid user to cover these problems. This system implements template account mechanism and manages local grid data.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.719-723
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• 2008

도달시간이 짧은 중소유역의 홍수예측과 돌발호우에 의한 돌발홍수의 예측을 위해서는 단기 예측 강우를 활용하는 기술이 필수적이라고 할 수 있다. 본 연구에서는 예측 강우를 이용한 신속하고 정확한 유출모의를 수행하는 과정으로서, 수치예보자료와 레이더 강우와 같이 격자 형태로 제공되는 강우자료를 직접 이용하여 유출모의가 가능한 1차원 분포형 강우-유출 모형을 개발하고자 한다. 본 연구에서 개발하고자 하는 모형은 모형의 입출력, 유출분석 모듈 등과 같은 모든 과정을 GIS 시스템과 완전 연계하고자 하며, 이를 통해서 그리드 형태로 제공되는 강우 시계열 자료와 공간자료를 화면상에서 조회할 수 있으며, 이를 모형의 입력자료로 직접 이용하고, 모의결과 또한 유역 내에서 공간 분포된 행태로 제시할 수 있다. 본 논문에서는 이와 같은 모형의 유출해석 과정과 이론적 검증 결과를 개략적으로 소개하고자 한다.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.597-600
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• 2002

In general, the function of intake structure, whether it be a open channel, a fully wetted tunnel, a sump or a tank, is to supply an evenly distributed flow to a pump station. An even distribution of flow, characterized by strong local flow, can result in formation of surface or submerged vortices, and with certain low values of submergence, may introduce air into pump, causing a reduction of capacity and efficiency, an increase in vibration and additional noise. Uneven flow distribution can also increase or decrease the power consumption with a change in total developed head. To avoid these sump problems pump station designers are considered intake structure dimensions, such as approaching upstream, baffle size, sump width, width of pump cell and so on. From this background, flow characteristics of intake within sump are Investigated numerically to obtain the optimal sump design data. The sump model is designed in accordance with HI code.

• Korean Journal of Computational Design and Engineering
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• v.5 no.3
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• pp.232-241
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• 2000

Even though we have greater chances to accomplish successful collaborative design by utilizing recent proliferation of networks, current practices do not fully take advantage of the information infrastructure. There are so much data over the networks, but not enough knowledge about the data is available to users. The main objectives of the product data interface system proposed in this paper are to capture more knowledge on managing product data and to provide users effective search capability. We define the metadata model for product data defined in STEP AP 203 and manage the metadata from product data in a repository system. Because we utilize the standard formats such as STEP for product data and RDF for metadata, the proposed approach can be applied to various fields of industries independently on commercial products.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.701-704
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• 2004

본 논문에서는 환전분포형 지표수-지하수 연계모형인 MIKE SHE 모형을 SWAT모형을 이용하여 산출된 소유역 유출량 자료 및 함양량 자료와 연계하여 국내 IHP 대표유역의 하나인 보청천 유역에 적용하였다. 실측유출량자료와 모의된 유출량자료를 비교하여 통계적 변량을 산출하여 모형을 평가하였으며, 그 결과 EI와 RMAE, $R^2$값은 각각 0.64와 0.74, 0.82를 나타내는 것으로 보아 모형이 실제를 만족스러울 정도로 잘 반영하고 있지는 못한다고 판단되었다. 이는 적용된 모형의 문제점이라기 보다 국내 실정에서 모형의 입력자료를 뒷받침할 만한 세분화된 자료의 부족에서 기인된 결과로 판단된다. 이에 따라 국내에서 완전분포형 모형의 입력자료를 뒷받침할 수 있는 시추 자료, 수리상수 자료 등이 확보되고 모형의 보정과 검정과정을 거친다면 더욱 만족스러운 결과를 얻어낼 수 있을 것으로 판단되며, 이러한 문제점이 해결, 보안된다면 본 모형의 국내 적용에는 큰 문제점은 없을 것으로 판단된다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1990.10a
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• pp.55-60
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• 1990

The objective of this study is to predict the nonlinear behavior of reinforced concrete shear walls, with the reinforcement uniformly distributed, under reversed cyclic loads. This study introduces joint Element Model which formulates the pulling out of rebars, slipping and intrusion of junction planes. The applicability of this study was experimental verfied by specimens SW1, SW2 and SW3 tested by authors, Wall1 by Paulay, SW16 and SW19 by Sheu. In almost specimen, the ratio of analytical to experimental maximum shear stress is within approximately 5%. In case of energy dissipation and maximum drift, the analytical results fully coincide with those of experiment.

• The Transactions of the Korea Information Processing Society
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• v.6 no.6
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• pp.1581-1589
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• 1999

In B-ISDN(Broadband Integrated Services Digital Networks), the efficient implementation of multicast function is very important since the demand for distributed type of service such as VOD(Video On Demand) system is expected to grow. In this paper, the multicast performance characteristics of fully-interconnected switch fabric used for our research is the proper architecture for a small-sized switch element, and it uses bit addressing method for addressing scheme and thus it is easy to implement multicast function without adding a function block. To incorporate the bursty nature of traffic in ATM networks, we used IBP(Interrupted Bernoulli Process) model as an input traffic model. We presented and analyzed the simulation results in terms of the multicast operation of the switch. Based. on this study, it its analyzed that congestion avoidance may be feasible if we use a proper traffic control scheme by finding an overload point due to multicast.

• Nuclear Engineering and Technology
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• v.55 no.3
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• pp.1140-1151
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• 2023

Fully Ceramic Microencapsulated (FCM) fuel is emerging advanced fuel material for the future nuclear reactors. The fuel pellet in the FCM fuel is composed of matrix and a large number of TRistructural-ISOtopic (TRISO) fuel particles which are randomly dispersed in the SiC matrix. The minimum layer thickness in a TRISO fuel particle is on the order of 10^-5 m, and the length of the FCM pellet is on the order of 10^-2 m. Hence, the heat transfer in the FCM pellet is a multi-scale phenomenon. In this study, three multi-scale heat conduction models including the Multi-region Layered (ML) model, Multi-region Non-layered (MN) model and Homogeneous model for FCM pellet were constructed. In the ML model, the random distributed TRISO fuel particles and coating layers are completely built. While the TRISO fuel particles with coating layers are homogenized in the MN model and the whole fuel pellet is taken as the homogenous material in the Homogeneous model. Taking the results by the ML model as the benchmark, the abilities of the MN model and Homogenous model to predict the maximum and average temperature were discussed. It was found that the MN model and the Homogenous model greatly underestimate the temperature of TRISO fuel particles. The reason is mainly that the conventional equivalent thermal conductivity (ETC) models do not take the internal heat source into account and are not suitable for the TRISO fuel particle. Then the improved ETCs considering internal heat source were derived. With the improved ETCs, the MN model is able to capture the peak temperature as well as the average temperature at a wide range of the linear powers (165 W/cm~ 415 W/cm) and the packing fractions (20%-50%). With the improved ETCs, the Homogenous model is better to predict the average temperature at different linear powers and packing fractions, and able to predict the peak temperature at high packing fractions (45%-50%).

• Wind and Structures
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• v.30 no.2
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• pp.141-153
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• 2020

Probabilistic information regarding directional extreme wind speeds is important for the precise estimation of the design wind loads on structures. A joint probability distribution model of directional extreme typhoon wind speeds is established using Monte Carlo simulation and empirical copula function to fully consider the correlations of extreme typhoon wind speeds among the different directions. With this model, a procedure for estimating directional extreme wind speeds for given return periods, which ensures that the overall risk is distributed uniformly by direction, is established. Taking 5 typhoon-prone cities in China as examples, the directional extreme typhoon wind speeds for given return periods estimated by the present method are compared with those estimated by the method proposed by Cook and Miller (1999). Two types of directional factors are obtained based on Cook and Miller (1999) and the UK standard's drafting committee (Standard B, 1997), and the directional risks for the given overall risks are discussed. The influences of the extreme wind speed correlations in the different directions and the simulated typhoon wind speed sample sizes on the estimated extreme wind speeds for a given return period are also discussed.