• Journal of applied mathematics & informatics
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• v.9 no.2
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• pp.459-517
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• 2002

The purpose of this paper is to provide a careful and accessible exposition of diffusive logistic equations with indefinite weights which model population dynamics in environments with strong spatial heterogeneity. We prove that the most favorable situations will occur if there is a relatively large favorable region (with good resources and without crowding effects) located some distance away from the boundary of the environment. Moreover we prove that a population will grow exponentially until limited by lack of available resources if the diffusion rate is below some critical value; this idea is generally credited to Thomas Malthus. On the other hand, if the diffusion rate is above this critical value, then the model obeys the logistic equation introduced by P. F. Verhulst .

• IE interfaces
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• v.3 no.1
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• pp.1-11
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• 1990

The purpose of this study is to develop the decision support model for the investment in the operation and maintenance in telecommunication networks. First, we analyze the relation between the cost of quality and the quality of service, and then establish and analysis tool of the investment alternatives for the improvement of the quality of service. This study will offer a decision tool to enhance an efficiency of the operation and maintenance for telecommunication facilities, and will contribute to shaping a policy of network performance management.

• Korean System Dynamics Review
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• v.16 no.3
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• pp.31-48
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• 2015

The purpose of this paper is to simulate drinking population, an alcoholic abuser and an alcoholic through therapy programs and system dynamic model. Then we try to research relationship between an alcoholic crime and related therapy programs. The results of the model simulation were consistently increased drinking population and 3 types drinkers until 2020 years. Specially the growth rate of drinking abusers will be passing that of a drinking population. Second, It showed clearly the decreasing effects of drinking crime on therapy programs(clinical treatment, preventive displine and counseling treatment). Finally, it will be positvely necessary the long-term and various alcoholic therapy program for reducing the ratio of drinking abusers and an alcoholic. In the second place, government and medical centers must be established a concrete information systems for collecting alcoholic datum.

• Korean Institute of Interior Design Journal
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• no.8
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• pp.32-38
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• 1996

The main focus of this paper is to apply contemporary aesthetics and psychological study with interior design analysis. Up to now, the methodology of interior design analysis has been developed toward a more qualitative way. By the virtue of the perception , congnition , and information theory, which oriented toward a quantitative approach, it became possible to investigate interior space analysis to a more objective and scientific ways. The purpose of this study is to investigate Modern and Post-Modern interior - architectural style with quantitative analytical method. The subjective interior critique studied by intuitive research will be transferred to scientific way by using quantitative formula . Savoye Villa and Guardiola House were selected as study model, because each architectural works ware regarded as masterpieces of Modern and Post-Modern style. These two oppositional style model will be distinguished with mathematical quantity by calculating Iave , Hmax, and Redundancy formula.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.103-108
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• 2013

This paper describes basic properties tests and non-rotating dynamic test for rotor blade, flexbeam, and torque tube of which bearingless rotor in helicopter consists. A basic properties test are bending and twist test to find the flap stiffness, lag stiffness, and twist stiffness of specimens. The purpose of dynamic test is to find natural frequencies and modes in non-rotating state. The test results are used to update the analysis model. The updated analysis results using rotorcraft comprehensive code match the tests quite well. The updated model input based on the tests will be utilized to analysis the conditions of rotating whirl tower test before the whirl test and will be compared with the whirl tower test results.

• Wind and Structures
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• v.16 no.6
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• pp.541-560
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• 2013

The aim of the paper is to use optimization and advanced numerical computation of a sail fiber-reinforced composite model to increase the performance of a yacht under wind action. Designing a composite-shell system against the wind is a very complex problem, which only in the last two decades has been approached by advanced modeling, optimization and computer fluid dynamics (CFDs) based methods. A sail is a tensile structure hoisted on the rig of a yacht, inflated by wind pressure. Our objective is the multiple criteria optimization of a sail, the engine of a yacht, in order to obtain the maximum thrust force for a given load distribution. We will compute the best possible yarn thickness orientation and distribution in order to minimize the total fiber volume with some displacement constraints and in order to leave the most uniform stress distribution over the whole structure. In this paper our attention will be focused on computer simulation, modeling and optimization of a sail-shape mathematical model in different regatta and wind conditions, with the purpose of improving maneuverability and speed made good.

• Proceedings of the KSR Conference
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• 1999.11a
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• pp.73-80
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• 1999

Belief revision involves integrating new information with the current belief. It is a ubiquitous human activity. A critical feature of belief revision lies in its sequential nature. Railroad system can be described as organic. Engine drivers take a great role in this system. Recently, Hogarth and Einhorn(1992) have Posited a belief-adjustment model for updating beliefs. Based on a sequential anchoring and adjustment strategy, the model is important fro decision makers. The sequential nature of information processing is affected by some task variables. This will be mainly explained in this paper. The purpose of this study is to examine the engine drivers' belief revision process and factors which influence on the belief revision process. The factors are the order and the experience. Thereby, this will contribute to the study of engine drivers' behavior. The result of this study is summarized as follows. The order effect due to the order of presentation of the evidence exist. The difference of belief revision is due to The experience level.

• Journal of KIBIM
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• v.12 no.1
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• pp.62-71
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• 2022

In order to overcome the limitations of th 2D method regardless of the client's request, the application of BIM was reviewed to create hight-quality products using 3D models and various BIM information for offshore wind jacket-type structures. First, we defined the input value through analysis of the target structure and wrote an algorithm(script library) and library to complete the BIM model. Design review using geometry information based on th BIM model, usage for visualization drawings and quantity calculation were reviewed. For the purpose of initial review, only libraries with a limited number of subjects limitations on the scope of research were used. However, in the futrue, various libraries will be developed and research will be conducted to expand the scope of subjects.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.835-840
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• 2009

Lately, Building Information Modeling (BIM) emerges as the most promising technology, now is expected to bring a great deal of improvement of productivity in every aspect of the construction industry. One of the BIM based scheduling is to use BIM model as a base for applying to schedule analysis and simulation tools. This type of tools may incorporate a various types of information such as the building model, construction method information, resource information, productivity information, rules and constraints to optimize activity sequencing. This paper proposes a framework of BIM based simulating system which can be used to optimize construction processes, especially for the floor construction cycle. For the purpose, all of the necessary components of the system will be defined and represented, and next an algorithm will be introduced to demonstrate the principle of simulating operation. The benefits of this technique are basically two : to test and optimize construction methods in respect of the construction duration and to reduce the floor construction cycle.

• The Journal of Society for e-Business Studies
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• v.4 no.2
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• pp.41-58
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• 1999

This paper is a study on a model of economic value of transmission speed of Internet Commerce. For this research, this paper searches the factors that influence the transmission speed of Internet and suggests the model for measurement of economic value. The model adopted in this research is CVM(contingent valuation method) using in environment economics and the research area in this paper is concentrated on Internet-based Electronic Commerce. For this purpose, this paper suggests econometrics model that measures customer's payment intention for transmission speed of Internet. This model can be used as the basic tool of feasibility of investment analysis and reasonable pricing on Internet service. For the more, it will be followed empirical study and more careful comprehension for objective validity of this study.