• Journal of Environmental Impact Assessment
• /
• v.8 no.4
• /
• pp.47-57
• /
• 1999

This study is aimed at the development of comprehensive environmental management system, which can be operated on the basis of world wide web, as a topic of G7 project. Even though there should be lots of works remaining to achieve this goal, preliminary products can be summarized as follows : 1) integrated environmental information management system, 2) web based control engine, 3) surface water environment management system, 4) subsurface water environment management system, 5) sewer and waterworks management system. The core methodology of the engine is the generalized multidimensional finite element matrices to depict the terms in the analysis of various partial differential equations. Spatial information management system (ArcView) and Visual Basic were extensively employed to construct GUI oriented web based engine. The developed systems were composed of very intense computer codes due to the necessity of combinatory management of environmental problems. The web based engine could be served as a decision tool for the integrated management of environmental projects in Korea.

• The Transactions of the Korea Information Processing Society
• /
• v.3 no.2
• /
• pp.369-380
• /
• 1996

Inductive Loop Detector(ILD) has been commonly used in collecting traffic data such as occupancy time and non-occupancy time. From the data, the traffic volume and type of passing vehicle is calculated. To provide reliable data for traffic control and plan, accuracy is required in type recognition which can be utilized to determine split of traffic signal and to provide forecasting data of queue-length for over-saturation control. In this research, a new recognition model issuggested for recognizing typeof vehicle from thecollected data obtained through ILD systems. Two clustering methods, based on statistical algorithms, and one neural network clustering method were employed to test the reliability and occuracy for the methods. In a series of experiments, it was found that the new model can greatly enhance the reliability and accuracy of type recongition rate, much higher than conventional approa-ches. The model modifies the neural network clustering method and enhances the recongition accuracy by iteratively applying the algorithm until no more unclustered data remains.

• Journal of Korean Society of Transportation
• /
• v.21 no.5
• /
• pp.19-29
• /
• 2003

The purpose of this study is to analyse the effect of the parking information on the waiting time using the simulation method. Stated Preference survey has been implemented to construct the parking lot choice model. A queue simulation is carried out to investigate the effect of various parking information on the waiting time. The results show that providing parking information is likely to increase the utilization of parking place and to decease the waiting time of individual vehicle. Furthermore, as the parking demand increases, the detailed and quantitative parking information such as "5 minutes delay" is more effective than qualitative parking information such as "available".

• Proceedings of the KOR-KST Conference
• /
• 1996.12a
• /
• pp.81-108
• /
• 1996

첨단교통정보시스템(ATIS)의 핵심 요소라 할 수 있는 동적경로안내 시스템(Dynamic Route Guidance System : DRGS)은 운전자가 목적지에 도착하기까지 실시간 교통정보를 토대로 최적경로를 안내해 줌으로써 날로 심화되어 가고 있는 교통혼잡을 최소화할 수 있으리라 기대를 모으고 있다. 특히 교통사고나 긴급도로공사 등으로 인해 발생하는 돌발적 교통혼잡하에서는 DRGS의 역할이 더욱 커질 것으로 예상되고 있다. 본 논문은 돌발적 교통혼잡하에서 보다 효과적인 DRGS의 경로 안내 알고리즘을 개발하는 데 그 목적이 있다. 이를 위해서 우선 하부구조기반(Infrastructure Based) DRGS와 개인차량기반(In-vehicle Based)DRGS의 장단점을 운전자, 교통행정당국, 그리고 교통체계관점에서 비교하였고, 시스템 아키텍쳐와 경로안내 알고리즘간의 상호관계를 규명하였다. 또한 효율적인 경로안내를 위해 사용자 평형(User Equilibrium)경로안내전략과 시스템최적화(System Optimal) 경로안내전략을 이상형 교통망(Idealistic Network)을 통해 비교분석하였다. 여기에는 현재 ITS-America에서 System Architecture 평가를 위해 사용한 INTEGRATION이라는 ITS Simulation Model과 그 통행저항함수를 사용하였다. 이를 토대로 돌발적 교통혼잡상황 아래서 사용자평형 경로안내를 제공할 경우 야기될 수 있는 Braess` Paradox 문제와, 총통행시간을 최소화하기 위한 시스템최적 경로안내를 제공할 경우 일어날 수 있는 사용자 호응도(User Compliance)문제를 동시에 고려한 적응형 동적경로안내 알고리즘을 개발하였다. 여기에는 돌발적 교통혼잡하에서 통행시간을 동적으로 예측하기 위해 이산형 확정적 대기행렬모형(Discrete Deterministic Queueing Model)이 사용되었다. 한편 알고리즘의 효율성을 평가하기 위해 이상형 교통망과, 실제 미국 Virginia 주의 Fairfax County에 소재한 주간 고속도로 66번(I-66)과 인접 교통망의 교통자료를 사용하여 각종 돌발교통 혼잡 상황을 전제로 한 Traffic Simulation과 정보제공시나\리오를 INTEGRATION Model을 이용해 실행하였다. 그 결과 적응형 알고리즘이 개개인의 최단시간 경로를 제공하는 사용자 평형 경로안내전략에 비해 교통혼잡도와 정체시간의 체류정도에 따라 3%에서 10%까지 전체통행시간을 절약할 수 있다는 결론을 얻었다.

• Journal of the Korean Chemical Society
• /
• v.39 no.10
• /
• pp.776-782
• /
• 1995

A theory of the helix/coil transition for $\alpha$ helical dimer such as $\alpha$ tropomycin and paramycin is developed. The treatment differs from those formulated previously for oligopeptide dimer which is explained by the matrix method using Zimm-Bragg parameter: In the present treatement, it is explained by the zipper model which can account for the dangling H-bond. We calculate the fractional helicity in $\alpha$ helical dimer as a function of helix initiation $constant(\sigma)$, helix stability constant(${\xi}$) and hydrophobic interaction parameter(w). For $\alpha$ tropomycin, the helix stability profile is also calculated. The transitions of this oligomer due to the change of temperature and the concentration of oligopeptide involve simultaneous dissociation of the dimer. The transitions of dimers which have cross-linked S-S bonds or have long chains don't occur, because they keep always helical structures. The transitons due to the concentration of the oligopeptides are steeper than those due to the chain length or temperature.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.7 no.3
• /
• pp.118-125
• /
• 2004

The purpose of this study is to decide an appropriate neighborhood and a transition rule of cellular automata by analyzing the past growth process of urban areas in Gimhae. With cellular automata which can manage the change based on the dynamic model and time, this study analyzes the urban growth of Gimhae from 1987 to 2001. Also, through the simulation of different types for neighborhood and transition rules, we can find the appropriate neighborhood and the transition rule for Gimhae. In conclusion, the forecast of physical urban growth pattern is more accurate under conditions when the number of matrixes for the neighborhood is small, the shape of the neighborhood is rectangular, "${\alpha}$" value, which control the pace of urban growth, is low and the transition possibility ($P_{ij}$) is high.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.18 no.2
• /
• pp.62-67
• /
• 2008

An Organometallic compound, $C_{12}H_{20}B_{10}S_2Co_2$, was synthesized from o-carborane, $Cp^*Co(S_2B_2B_{10}H_{10})$ and $BH_3{\cdot}THF$. The molecular structure of this complex has been determined by X-ray diffraction. Crystallographic data: monoclinic, space group Cc, a=15.981(4) ${\AA}$, b=15.478(17) ${\AA}$, c=12.0562(17) ${\AA}$, ${\beta}=115.063(16)^{\circ}$, Z=4, V=9683(4) ${\AA}^3$. The structure was solved by direct methods and refined by full-matrix leat-squares methods to give a model with a reliability factor R = 0.0630 for 9948 reflections.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.39 no.2
• /
• pp.1-10
• /
• 2016

In this paper, we present a new way to derive the mean cycle time of the G/G/m failure prone queue when the loading of the system approaches to zero. The loading is the relative ratio of the arrival rate to the service rate multiplied by the number of servers. The system with low loading means the busy fraction of the system is low. The queueing system with low loading can be found in the semiconductor manufacturing process. Cluster tools in semiconductor manufacturing need a setup whenever the types of two successive lots are different. To setup a cluster tool, all wafers of preceding lot should be removed. Then, the waiting time of the next lot is zero excluding the setup time. This kind of situation can be regarded as the system with low loading. By employing absorbing Markov chain model and renewal theory, we propose a new way to derive the exact mean cycle time. In addition, using the proposed method, we present the cycle times of other types of queueing systems. For a queueing model with phase type service time distribution, we can obtain a two dimensional Markov chain model, which leads us to calculate the exact cycle time. The results also can be applied to a queueing model with batch arrivals. Our results can be employed to test the accuracy of existing or newly developed approximation methods. Furthermore, we provide intuitive interpretations to the results regarding the expected waiting time. The intuitive interpretations can be used to understand logically the characteristics of systems with low loading.

• Journal of the Korean association of regional geographers
• /
• v.6 no.3
• /
• pp.169-184
• /
• 2000

Industrial clusters and their boundaries are identified by factor and hot spot analyses for the greater Cincinnati metropolitan area in USA. While traditional input-output approach identified aspatial industrial clusters, this study combines traditional approach with GIS techniques to identify their boundaries. Combining the results of input-output industrial clusters with the leading industries groups, we have identified five leading industry clusters. They are food (20), chemicals (28), metal manufacturing (32), metal products (33), and machinery (35). We also used hot spot analysis to visualize each industry cluster on the research area by using Arcview software. Determining the degree to which such industries are associated spatially and their spatial delimitation may be an additional approach to measuring the efficiency of the spatial organization of an economy. It is hoped that the industrial clusters and industrial spatial clusters approaches may also proved the basis for the development of new models of the spatial arrangement of industry at a level more aggregated than that of the single plant or firm.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.21 no.2
• /
• pp.108-116
• /
• 2009

The present study introduces a Legendre interpolation function which is capable of analyzing wave transformation effectively in a finite element method. A Lagrangian interpolation function has been mostly used for a finite element method with a higher-order interpolation function. Although this function has an advantage of giving an accurate result with less number of elements, simulation time increases. Calculation time can be reduced by mass lumping, whereas the accuracy of solution is lowered. In this study, we introduce a modified Lagrangian interpolation function, Legendre cardinal interpolation, which can reduce simulation time with keeping up favorable accuracy. Through various numerical simulations using a Boussinesq equations model, the superiority of the Legendre cardinal interpolation function to a Lagrangian interpolation function was shown.