• Water for future
• /
• v.28 no.1
• /
• pp.153-168
• /
• 1995

The purpose of this study is to develop an efficient model for the least cost design of multisite detention systems. The IDP (Incremental Dynamic Programming) model for optimal design is composed of two sub-models: hydrologic - hydraulic model and optimization model. The objective function of IDP is the sum of costs; acquisition cost of the land, construction cost of detention basin and pumping system. Model inputs include channel characteristics, hydrologic paramenters, design storm, and cost function. The model is applied to the Jung- Rang Cheon basin in Seoul, a watershed with detention basins in multiple branching channels. The application results show that the detention system can be designed reasonably for various conditions and the model can be applied to multi-site detention system design.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.28 no.3
• /
• pp.267-273
• /
• 2004

The purpose of this paper is to develop a systematic design method for the suspension system hard points and compliance elements, which have great influence on the handling stability of a vehicle. In this paper, a method to optimize J-turn responses is presented based on the principles of design of experiments, multi-body dynamic analysis and optimum design technique. The design variables associated with the J-turn maneuver are selected through the experimental design sensitivity analysis using the perturbation method. An objective function is defined as an approximate function for the J-turn characteristics using the TSA(Taylor series approximation). The values of the design variables, which make the optimized J-turn characteristics, are obtained using the conjugate gradient method. The result of the J-turn simulation shows that the optimized vehicle has more improved handling stability than the optimized vehicle.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.12 no.5
• /
• pp.451-461
• /
• 2002

Differential evolution(DE) has been preyed to be an efficient method for optimizing real-valued multi-modal objective functions. DE's main assets are its conceptual simplicity and ease of use. However, the convergence properties are deeply dependent on the control parameters of DE. This paper proposes an adaptive differential evolution(ADE) method which combines with a variant of DE and an adaptive mechanism of the control parameters. ADE contributes to the robustness and the easy use of the DE without deteriorating the convergence. 12 optimization problems is considered to test ADE. As an application of ADE the paper presents a supervised clustering method for predicting events, what is called, an evolutionary event clustering(EEC). EEC is tested for 4 cases used widely for the validation of data modeling.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.1B
• /
• pp.136-143
• /
• 2010

In this paper, we investigate decode-and-forward (DF) relaying systems with a direct link between the source and the destination node. The objective of this paper is to determine the better relaying strategy between 3-hop DF relaying and dual-hop DF relaying with the best relay selection. Assuming Rayleigh fading channels, we present closed-form outage probability of the 3-hop relaying and the dual-hop relaying, respectively, and compare the performances by numerical investigation. Numerical results show that if the channel is poor, the outage performance of the 3-hop relaying is better than the dual-hop relaying.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.31 no.6B
• /
• pp.551-563
• /
• 2011

Water resource projects need an enormous national budget. Therefore, a reasonable and reliable decision making is required for the planning of water resource projects, but decision making has been mostly performed by economic analysis. The objective of this study is to develop a Multi-criteria Decision Making(MCDM) model which can assess the project in various aspects for the selection of preferable alternative and determination of investment priority in water resource projects. In this study, the criteria involves economic feasibility, policies, vulnerability, and sub-items which have weights obtained from the expert survey for the consistent evaluation. We also derived the utility function considering risk trend of each item based on the expert survey. Then, the total score was estimated by weights of each item and utility score of each attribute. The results show that vulnerability is a major contributor for the criteria. This study will contribute to the selection of proper water resource projects considering efficiency of project and fairness for vulnerable area.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.5 no.1
• /
• pp.1-12
• /
• 1985

This study is conserned for the optimum design of reinforced concrete slab-beam-column structures with multi-storys and multi-bays by Direct Method. Flexural and shear strength, sectional size, and steel ratio etc., were considered as the design-constraints and the cost function was taken as to objective function. They became high degree nonlinear problems. Using SLP as an analytical method of nonlinear optimal problems, an optimal algorithm was developed in this study and the algorithm was applied to the optimization of reinforced concrete structure system of 5 storys. The result converged to a optimal solution with 3 to 5 iterations, and proved that economical design could be possible when compared with conventional designs.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.21 no.2
• /
• pp.191-204
• /
• 2005

Traditionally, the implant treatment require load-free healing period of at least 3 months in the mandible and 6 months in the maxilla. But this long healing period provides patients with the discomfort and economical trouble. Many experiments has been attempted for the outcome of such disadvantage, so recently the immediate loaded implant is getting popularity. Several literature has been published for clinical success of immediate loaded implant. The studies for the success rate of immediate loaded implant in multi-way has been reporting, nevertheless, we don't have yet a probable success. Various studies have been practiced that the advantages and disadvantages associated with immediate loaded implant, and factors that may influence the success of immediate implant, including patient selection, type of bone quality, required implant length, structure of the implant, surgical skill, need for achieving primary stability, control of occlusal force, peri-implant bone activity. The objective of this study is to review the literature related to immediate loading of implants and to discuss factors that may influence this treatment modality, based on scientific evidence.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.05a
• /
• pp.462-465
• /
• 2002

This paper deals with the problem of synthesis of stable and optimal grasps with unknown objects by 3-finger hand. Previous robot grasp research has analyzed mainly with either unknown objects 2D by vision sensor or unknown objects, cylindrical or hexahedral objects, 3D. Extending the previous work, in this paper we propose an algorithm to analyze grasp of unknown objects 3D by vision sensor. This is archived by two steps. The first step is to make a 3D geometrical model of unknown objects by stereo matching which is a kind of 3D computer vision technique. The second step is to find the optimal grasping points. In this step, we choose the 3-finger hand because it has the characteristic of multi-finger hand and is easy to modeling. To find the optimal grasping points, genetic algorithm is used and objective function minimizing admissible farce of finger tip applied to the object is formulated. The algorithm is verified by computer simulation by which an optimal grasping points of known objects with different angles are checked.

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.11
• /
• pp.54-64
• /
• 2002

This paper deals with the problem of synthesis of stable and optimal grasps with unknown objects by 3-finger hand. Previous robot grasp research has mainly analyzed with either unknown objects 2-dimensionally by vision sensor or known objects, such as cylindrical objects, 3-dimensionally. As extending the previous work, in this study we propose an algorithm to analyze grasp of unknown objects 3-dimensionally by using vision sensor. This is archived by two steps. The first step is to make a 3-dimensional geometrical model for unknown objects by using stereo matching. The second step is to find the optimal grasping points. In this step, we choose the 3-finger hand which has the characteristic of multi-finger hand and is easy to model. To find the optimal grasping points, genetic algorithm is employed and objective function minimizes the admissible force of finger tip applied to the objects. The algorithm is verified by computer simulation by which optimal grasping points of known objects with different angle are checked.

• Korean Journal of Hydrosciences
• /
• v.4
• /
• pp.1-9
• /
• 1993

It is a major objective for the management and operation of water resources system to forecast streamflows. The applicability of artificial neural network model to hydrologic system is analyzed and the performance is compared by statistical method with observed. Multi-layered perception was used to model rainfall-runoff process at Pyung Chang River Basin in Korea. The neural network model has the function of learning the process which can be trained with the error backpropagation (EBP) algorithm in two phases; (1) learning phase permits to find the best parameters(weight matrix) between input and output. (2) adaptive phase use the EBP algorithm in order to learn from the provided data. The generalization results have been obtained on forecasting the daily and hourly streamflows by assuming them with the structure of ARMA model. The results show validities in applying to hydrologic forecasting system.