• Journal of the Korean Professional Engineers Association
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• v.30 no.4
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• pp.99-116
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• 1997

In order to obtain safe drinking water, free from surface contamination, a study to determine the potential for developing a bank-filtrate system in the Iryong and Yongsan, Nakdong River Basin, Korea was conducted. The main type of aquifer In the study area is alluvial, consisting mostly of sand and gravel. The hydraulic conductivity(k) of the Iryong and Yongsan test areas were 8.63${\times}$10$^-2$cm/s and 9.90${\times}$10$^-2$cm/s, respectively, indicating that these areas are satisfactory for bank filtrate production. Pilot plants(IRPL and YSPL) were set up In Iryong and Yongsan to monitor the change in the quality of bank-filtered water and to determine the effect pumping had on the surrounding hydrogeologic system. The pilot plants operated continuously for about two months and the data obtained were used to validate the groundwater flow model. Computer simulations were conducted to predict the effects of producing bank filtrate using MODFLOW. MODPATH was also linked with the flow model to analyze particle tracking. According to the results of the model simulations and the hydrogeologlc study, long-term pumping, the minimization of drawdown and the availability of uncontaminated sell and groundwater conditions for the catchment area were all Important factors for successful bank-titrate system development.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.7
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• pp.504-512
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• 2008

The characteristics of nonpremixed oxy-fuel flame in a multi-jet burner were experimentally and numerically investigated. The overall flow rate of fuel and oxygen was fixed, and the oxygen feeding ratio (OFR) was varied by 0.25, 0.5, and 0.75. The results of numerical simulation were compared with the measured results which are temperature profile and direct flame observation. The probability density function (PDF) model was applied accounting to the description between turbulence and chemistry, and standard ${\kappa}-{\varepsilon}$ model was used for turbulent flow field. Equilibrium assumption is very reasonable due to fast chemistry of the oxy-fuel combustion. Thus, the equilibrium calculation based on Gibbs free energy minimization was guaranteed to generate the solution of the oxy-fuel combustion. The result was obtained by numerical simulation. The predicted radial temperature profiles were in good agreement with the measured results. The flame length was shorten and was intensified with the decrease of OFR because the mixture of fuel and oxidizer are fast mixed and burnt. The maximum temperature became lower as the OFR increased, as a consequence of large flame surface area.

• Journal of the Korea Computer Graphics Society
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• v.4 no.1
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• pp.31-40
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• 1998

Active Contour Model(ACM) is an efficient method for segmenting an object. The main shortcoming of ACM is that its result is very dependent on the shape and location of an initial contour. To overcome this shortcoming, a new segmentation algorithm is proposed in this paper. The proposed algorithm uses B-splines to describe the active contour and applies Simulated Annealing (SA) and Genetic Algorithm(GA) as energy minimization techniques. We tried to overcome the initialization problem of traditional ACM and compared the result of ACM using GA and that using SA with 2D synthetic binary images. CT and MR images.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.3
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• pp.75-85
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• 2014

This paper is to develop and estimate a closed form inflation model using the estimates for real marginal costs in manufacturing industries during the sample period 1975-2010. The production function in manufacturing industry incorporates labor, capital, domestic material, and foreign material, assuming constant returns to scale technology and AR(1) process of technological coefficient. We derive real marginal costs from firm's cost minimization with quarterly data and provide new evidences on the new Keynesian Phillips curve for Korea. The main empirical result is that the closed form coefficients ${\delta}_1$ and ${\delta}^{-1}_2$ in manufacturing for PPI inflation proved to be 0.5086 and 0.8779 respectively, similar to the estimates in the U.S. case. These results also are consistent with the functional relationship between the coefficients in hybrid model and its closed form. Thus the paper suggests that the empirical studies on inflation dynamics need to focus on the manufacturing industry with market power, treating PPI inflation as the dependent variable.

• Journal of the Korea Institute of Building Construction
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• v.12 no.6
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• pp.648-663
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• 2012

With recent attempts to improve quality and productivity, the prefabrication manufacturing system has been occupying an increasing share of the construction area. To minimize site work, material is more frequently being produced and partially assembled at a plant, and then installed at a site. For this reason, the production process is being divided and the materials are being delivered to the site after passing through multiple plants. With these changes in the production process, the materials delivery plan is becoming an important management point. In particular, as road transportation using trucks has a 71 percent share of the domestic transportation market, selecting the proper transportation path is important when delivering materials and equipment to a site. But the management system at the project design phase to calculate the delivery cost by considering the production process of the pre-fab material and the $CO_2$ emission at the material delivery phase is currently lacking. This study suggests a process design model for assembly production of the pre-fab material and transportation logistics based on carbon emission. The suggested model can be helpful to optimize the location of the intermediate plant. It is expected to be utilized as a basic model at the project plan and design phase when subcontractors make decisions on items such as materials procurement, selecting the production method, and choosing the location of the assembly plant.

• Korean Journal of Child Studies
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• v.33 no.2
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• pp.185-201
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• 2012

The purpose of the present study was to investigate the structural relationships between adolescent problem behaviors and related variables. The subjects of this study consisted of 250 to second graders from a middle school in S city in the Gyeongbuk province of South Korea. The sample variance-covariance matrix was analyzed using AMOS 20.0, and a maximum likelihood minimization function. The results were as follows : First, marital conflict in terms of the father's open communication model indicated both a direct and indirect effect upon adolescent problem behaviors. Marital conflict in terms of the father's problematic communication model revealed an indirect effect upon adolescent problem behaviors also indicated that these behaviors were also mediated by the father's problems communication. Second, a open communication style on the part of the father indicated a partially mediating effect on the relationship between marital conflict and adolescent problem behaviors. The problematic communication model on the part of the father revealed a very clear mediating effect on the relationship between marital conflict and adolescent problem behaviors.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.4
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• pp.582-591
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• 2001

It is known that the reduced integration, modified shape function, anisoparametric and non-conforming element can reduce the error induced by stiffness locking phenomenon in the finite element analysis. In this study, we propose new anisoparametric curved beam element. The new element based on reduced minimization theory is composed of different shape functions in each displacement field. By the substitution of this modified shape function, the unmatched coefficient that cause stiffness locking in the constraint energy is eliminated. To confirm the availability of this new model, we performed numerical tests for a simple model. As a result of numerical test, the undulate stress patterns are disappeared in static analysis, and displacements and stresses are close to exact solution. Not only in the static analysis but also in the eigen analysis of free vibrated curved beam model, this element shows successful convergent results.

• Journal of Ocean Engineering and Technology
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• v.34 no.4
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• pp.253-262
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• 2020

This study provides a comparative analysis of experiments-based enhancements and sensitivity evaluations for the structural design of an automatic ocean salt collector under various load conditions. The sizing variables of the structural members were considered as design factors. The strength and weight performances were selected as output responses. The design of experiments used in the comparative study consisted of the orthogonal array design, Box-Behnken design, and central composite design. The response surface model, one of the metamodels, was applied to the approximate model generation. The design enhancement performance metrics, including numerical costs and weight minimization, according to the design of experiments, were compared from the best design case results. The central composite design method showed the most enhanced design results for the structural design of the automatic ocean salt collector.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.1
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• pp.178-186
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• 1996

We develop a simple adaptive population coding model for neural networks based upon an error minimization method. Our model exhibits properties that have been experimentally observed in the population coding of the motor-cortical cells during the voluntary arm movements of primates. By removing a group of directionally tuned cells after learning, we study its contribution to the population coding. Through the learning process of the remained cells, we observe how the cells modify their preferred directions to reduce the coding errors. Since this adaptive property has been neither predicted nor experimentally observed before, it would be interesting to find whether a similar adaptive property exists in real cortices that are believed to encode the information in their cell populations.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.5
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• pp.118-125
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• 2003

This paper presents a scheme for the placement of dispersed generator systems(DGs) based on load model in unbalanced systems. Groups of each individual load model consist of residential, industrial, commercial, official and agricultural load The main idea of solving fuzzy goal programming is to transform the original objective function and constraints into the equivalent multi-objectives functions with fuzzy sets to evaluate their imprecise nature for the criterion of power loss minimization, the number or total capacity of DGs and the bus voltage deviation, and then solve the problem using genetic algorithm The method proposed is applied to IEEE 13 bus unbalanced distribution systems to demonstrate its effectiveness.