• The Journal of Fisheries Business Administration
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• v.33 no.2
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• pp.31-48
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• 2002

This paper is aimed to analyze how to evaluate the choice of optimal management measures and level of control in fisheries management under the costly and imperfect management system by comparing with costless and perfect management system that is commonly assumed in the analysis of fisheries regulations. Fishermen would set the level of fishing efforts at the point where the marginal fishing profit for fishing effort is equal to the marginal level of fine under costly and imperfect management system. Therefore, under the case where the marginal fishing profit is higher than the marginal level of fine, the level of fishing efforts would be made at the point which is higher than the level of fishing efforts made under costless and perfect management system and is not a point where the economic profit is maximized in regulated fisheries. From this conclusion, the fishermens avoidance activities against regulations as well as the level of control in fisheries management substantially have an influence on the choice of fisheries management instruments. According to the analysis of optimal fisheries management policy, the economic profits in regulated fisheries are determined by the level of fisheries enforcement costs and total fishing profits, in which as enforcement costs increase the economic profits decrease. In addition, the economic profits vary in response to the level of control in avoidance activities. That is, as avoidance costs decrease, the economic profits increase. The determination of optimal level of control in fisheries management should be made at the point where the marginal regulation costs are equal to the marginal profits from regulated fisheries, in which marginal regulation costs are different according to the type of management measures. And the level of profits changes in response to different levels of avoidance activities. The management measure that can maximize the difference between the marginal regulation costs and marginal profits from regulated fisheries should be chosen as an optimal fisheries management instrument.

• Fashion & Textile Research Journal
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• v.11 no.5
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• pp.788-798
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• 2009

This study aims to develop a highly reproducible, optimal frame design algorithm using variations in the curvature of armscye circumference, which will provide the basics for remodeling the 3D human body shape with the concept of reverse design used to develop total contents for the apparel industry. 1. The results of the experiment proved that ratio value was significantly efficient than absolute value of curvature variation to extract feature points in the armscye circumference 2. For the shoulder(1st and 2nd quadrant) and front armhole(3rd quadrant) parts of the armscye circumference, frame remodeling with the positive point of inflection led to the completion of a highly reproducible frame. 3. Similarly, even for the rear armhole part(4th quadrant) in the armscye circumference, it was found that frame remodeling using the positive maximum point of inflection resulted in highly reproducible body shape with the maximum point of inflection situated within the range of split angles $305^{\circ}{\sim}330^{\circ}$, while frame remodeling using simultaneously the two largest points of inflection including maximum point of inflection led to highly reproducible body shape with the maximum point of inflection out of the range $305^{\circ}{\sim}330^{\circ}$. 4. Based upon the optimal frame design algorithm developed in this study, section-specific feature points in the armscye circumference were extracted depending on the rate of curvature variation and remodeling with spline curves was conducted. The results indicate a remarkably high reproducibility(98.6%) and suggest that the algorithm developed in this study is suitable for human body modeling.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.1
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• pp.1-10
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• 2013

Major issues in water supply service have changed from expansion of service area to improvement of service quality, i.e., water quality and safety, and early response to emergency situation. This change in the service concept triggers the perceptions of limitation with the current centralized water supply system and of necessities of decentralized (distributed) water supply system (DWSS), which can make up the limitations. DWSS can reduce the possibility of water supply outage by establishing multiple barriers such as emergency water supply system, and secure better water quality by locating treatment facilities neighboring consumers. On the other hand, fluctuation of water demand will be increased due to the reduced supply area, which makes difficult to promptly respond the fluctuating demand. In order to supplement this, hybrid water supply system was proposed, which combined DWSS with conventional water supply system using distributing reservoir to secure the stability of water supply. The Optimal connection point of DWSS to existing water supply network in urban area was determined by simulating a supply network using EPANET. Optimal location of decentralized water treatment plant (or connection point) is a nodal point where changes in pressure at other nodal points can be minimized. At the same time, the optimal point should be selected to minimize hydraulic retention time in supply network (water age) to secure proper water quality. In order to locate the point where these two criteria are satisfied optimally, Distance measure method, one of multi-criteria decision making was employed to integrate the two results having different dimensions. This methodology can be used as an efficient decision-support criterion for the location of treatment plant in decentralized water supply system.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.10
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• pp.480-488
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• 2001

This paper presents a technique that can obtain an optimal solution for the Security-Constrained Economic Dispatch (SCED) problems using the Interior Point Method (IPM) while taking into account of the power flow constraints. The SCED equations are formulated by using only the real power flow equations from the optimal power flow. Then an algorithm is presented that can linearize the SCED equations based on the relationships among generation real power outputs, loads, and transmission losses to obtain the optimal solutions by applying the linear programming (LP) technique. The objective function of the proposed linearization algorithm are formulated based on the fuel cost functions of the power plants. The power balance equations utilize the Incremental Transmission Loss Factor (ITLF) corresponding to the incremental generation outputs and the line constraints equations are linearized based on the Generalized Generation Distribution Factor (GGDF). Finally, the application of the Primal Interior Point Method (PIPM) for solving the optimization problem based on the proposed linearized objective function is presented. The results are compared with the Simplex Method and the promising results ard obtained.

• Journal of Korean Society on Water Environment
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• v.27 no.1
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• pp.9-18
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• 2011

In this study the optimal volume for non-point source control retention is estimated considering spatio-temporal variation of land surface. The 3-parameter mixed exponential probability density function is used to represent the statistical properties of rainfall events, and NRCS-CN method is applied as rainfall-runoff transformation. The catchment drainage area is divided into individual $30m{\times}30m$ cells, and runoff curve number is estimated at each cell. Using the derived probability density function theory, the stormwater probability density function at each cell is derived from the rainfall probability density function and NRCS-CN rainfall-runoff transformation. Considering the antecedent soil moisture condition at each cell and the spatial variation of CN value at the whole catchment drainage area, the ensemble stormwater capture curve is established to estimate the optimal volume for an non-point source control retention. The comparison between spatio-temporally varied land surface and constant land surface is presented as a case study for a urban drainage area.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.462-467
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• 2003

As for control systems, many researchers give optimal structures of the finite-word-length compensator. D. Williamson solved a fixed-point case against colored noise for the LQG problem. Recently, one of the authors derived an optimal filter against colored noise. And consequently, we apply the result to a twodegree-of-freedom control system in this paper. In addition the perturbation of the coefficients is considered. Furthermore, simulation results indicate this method gives better than other structures.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.5
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• pp.122-130
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• 2001

In this paper, an operational algorithm for a 2-shaft parallel hybrid electric vehicle is suggested for the minimization of operation cost. The operation cost is obtained as a summation of the engine fuel cost and the motor electricity cost. The electrical cost function is estimated in case of motoring, and generating when the recuperation is carried out during the braking. In addition, weight function is introduced in order to maintain the battery state of charge. Based on the operation algorithm, the optimal engine operation point that minimizes the operation cost is obtained with respect to the required vehicle power for every state of charge of battery. The optimal operation point provides the optimal power distribution of the engine and the motor for a required vehicle power Simulation was performed and the fuel economy of the hybrid vehicle was compared to that of the conventional vehicle. Simulation results showed that hybrid vehicle's fuel economy can be improved as much as 45∼48% compared to the conventional vehicle's.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.11
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• pp.30-39
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• 2012

The characteristics of I-V and P-V of solar cell nonlinearly changes according to irradiation, temperature and load. Therefore, to use efficiently PV system, operating point must be always operating at maximum power point. Also, PV system is semiconductor, so it generates loss by temperature. But because of conventional MPPT methods are not considering temperature, it has problem which decrease efficiency. This paper proposes temperature measurement based optimal voltage(TMOV) MPPT algorithm using temperature measurement based optimal voltage. It analyzes characteristics of solar cell according to irradiation and temperature and conventional MPPT methods. The TMOV control algorithm proposed in this paper is compared and analyzed conventional MPPT methods. The validity of this paper proves using this result.

• Journal of the Korean Data and Information Science Society
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• v.26 no.1
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• pp.255-260
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• 2015

Among many optimal threshold criteria from ROC curve, the closest-to-(0,1) and amended closest-to-(0,1) criteria are considered. An ROC curve that passes close to the (0,1) point indicates that two models are well classified. In this case, the ROC curve is located far from the (1,0) point. Hence we propose two criteria: the farthest-to-(1,0) and amended farthest-to-(1,0) criteria. These criteria are found to have a relationship with the KolmogorovSmirnov statistic as well as some optimal threshold criteria. Moreover, we derive that a definition for the proposed criteria with more than two dimensions and with relations to multi-dimensional optimal threshold criteria.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.64-66
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• 1995

This paper presents a new approach to evaluate optimal basic reliability indices of electric distribution systems using genetic algorithm. The use of optimal reliability evaluation is an important aspect of distribution system planning and operation to determine adequacy reliability level of each area. In this paper, the reliability model is based on the analytical method, connecting component failure to load point outage in each section. The proposed method applies genetic algorithm to calculate the optimal values of basic reliability indices, ie. failure rate and repair time, for a load point in the power distribution system, subject to minimizing interruption cost. Test results for the model system are reported in the paper compared with a direct optimization method(gradient projection).