• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.321-322
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• 2015

An area of severity (AOS) assessment is defined as a set of the fault positions that can result in the voltage sag bigger than certain level for sensitive buses simultaneously. Using the AOS assessment, the location of devices for compensating voltage sag can be determined as the site expected to less voltage sag at the sensitive bus. The energy storage system based on the control strategy emulating the traditional synchronous generator can contribute the fault current with fast response. Therefor are of venerability (AOV) can be reduced. The energy storage system installed by the AOS assessment has function which can experience relatively less voltage sag in addition to the conventional role of energy storage.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.2
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• pp.189-199
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• 2000

This paper investigates the thermodynamic performance of latent heat thermal energy storage system using two phase change materials(2-PCM system). The thermodynamic merit of using 2-PCM is clear in terms of exergetic efficiency, which is substantially higher than that of 1-PCM system. Optimum phase change temperature to maximize the exergetic efficiency exists for each case. The heat transfer area ratio of high temperature storage unit, X, becomes another important parameter for 2-PCM system if the phase change temperatures of given materials are different from those of optimum conditions. It is a good approximation for X$_{opt}$ to be 0.5 when optimum phase change temperatures are used. Otherwise X$_{opt}$ is determined differently as a function of given phase change temperatures.res.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.6
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• pp.451-455
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• 2022

Glycogen storage disease (GSD) is a group of inherited disorders, which result in the deficiency of enzymes involved in glycogen metabolism, leading to an accumulation of glycogen in various organs. Deficiency of amylo-1-6-glicosidase (debranching enzyme) causes glycogen storage disease type III (GSD III). The main problems that anesthesiologists face in patients with GSD III include hypoglycemia, muscle weakness, delayed awakening due to abnormal liver function, possible difficulty in airway, and cardiomyopathy. In the face of these difficulties, airway preparation and appropriate glucose monitoring and support during the fasting period are important. The doses of the drugs to be used should be calculated considering the increased volume of distribution and decreased metabolic activity of the liver. We present the case of a child with GSD IIIa who underwent dental prosedation under general anesthesia. She was also being prepared for liver transplantation. This case was additionally complicated by the patient's serious allergic reaction to eggs and milk.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.4
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• pp.58-66
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• 1998

Irrigation Reservoir Water Supply Index(IRWSI), which can be applied to the effective supply and management of the irrigation water resources, was developed. IRWSI was formulated as resealed nonexceedance probabilities of two hydrologic components : reservoir storage ratio and precipitation. To generate nonexceedance probability of hydrologic component, it was important to define the optimal one among the various probability distribution function in the state of nature. To define an optimal probability distribution, in this study, four types of probability distribution function were tested by the K-S fitting, and for the calculation of IRWSI, reservoir storage ratio(%) and precipitation used Normal distribution & Gamma distribution, respectively. In this study, the weight coefficients of a and b for each hydrologic component, which is precipitation and reservoir storage ratio, was decided as 0.8 and 0.2, respectively. While some studies changed weight coefficients according to the size of basin area, this study used same values without considering that. From the analysis of drought characteristics, it was found that the IRWSI was sensitive to the size of irrigation area rather than the size of basin area, and the south-eastern region of Korea had been suffered from severe drought damage.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.2
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• pp.56-64
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• 1998

Multi-layered perceptrons that are a nonlinear neural network model, have been widely used for various applications mainly thanks to good function approximation capability for nonlinear fuctions. However, for digital hardware implementation of the multi-layere perceptrons, the quantization scheme using "look-up tables (LUTs)" is commonly employed to handle nonlinear signmoid activation functions in the neworks, and thus requires large amount of storage to prevent unacceptable quantization errors. This paper is concerned with a new effective methodology for digital hardware implementation of multi-layered perceptrons, and proposes a "piecewise affine approximation" method in which input domain is divided into (small number of) sub-intervals and nonlinear sigmoid function is linearly approximated within each sub-interval. Using the proposed method, we develop an expression and an error backpropagation type learning algorithm for a multi-layered perceptron, and compare the performance with the quantization method through Monte Carlo simulations on XOR problems. Simulation results show that, in terms of learning convergece, the proposed method with a small number of sub-intervals significantly outperforms the quantization method with a very large storage requirement. We expect from these results that the proposed method can be utilized in digital system implementation to significantly reduce the storage requirement, quantization error, and learning time of the quantization method.quantization method.

• Journal of the Korea Furniture Society
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• v.26 no.4
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• pp.346-355
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• 2015

It suggests a closet design for infants in consideration of space utilization, furniture arrangement, and goods storage by integrating a baby's closet and toy chest, which was used for storage of baby's toys and play instrument. For this, it conducted and analyzed data research on the infants' toy chests in the domestic and overseas market and based on such approach, the colors that helped development of infants' cognition and emotion were selected while suggesting familiar animal characters for infants. Without considering separate arrangement of furniture and toy chest within limited space, it allowed space utilization and provided enough storing space. Also, the attached ball casters enabled easy carry of the closet and with this function, it helps infants arrange and store goods by themselves so that making them feel a sense of accomplishment. For effective spatial utilization as well as security of its genuine storage function, the closet and toy chest were combined in this study. Thus, it is believed that development of such multifunctional furniture will suggest the direction of researches on domestic furniture development that are conducted to maximize utilization of residential space for the people living today.

• Journal of the Korea Furniture Society
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• v.23 no.4
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• pp.342-354
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• 2012

This study aimed at acknowledging characteristics of space usage and suggesting orientation of space planning and furniture designing that meet various residents' demands correlating with residential area, furniture and family members by doing fact finding of volume of the furniture in medium/small sized apartment. The contents of the study are "experience of functional remodeling," "a number of bedrooms correlating with a number of family" and "furniture arrangement of each space and characteristics of space utilization" based on forty six cases. Followings are results of the study. 1) It was acknowledged that the function of space relating to family members largely depends on furniture arrangement correlating with age of children. It is needed that flexible planning of residential area to meets growing children and various family demands. 2) Functional remodeling requires furniture rearrangement attended with the remodeling. Thus, it is required that ideas in more simple and efficient furniture designing and consideration of construction environment embracing that ideas. 3) It can be acknowledged that the most demanding matter to enjoy satisfied and comfortable life in residential area is the matter of storage area. It is also understandable that the matter can be worse by time going by and the change of living pattern. Therefore, it is required that the consideration of enough storage area compatible with its function of the room and the planning of built-in furniture for storage.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.3
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• pp.1-16
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• 2006

The purpose of this study is to develop design model of ecological park as stormwater storage facilities. The results are as follows : First, the design model of ecological park as stormwater storage facilities consider ecological and landscape characteristics such as high efficiency of land use, function as disaster prevention, ecological water purification, formation of habitat for flora and fauna. Second, this study demonstrates two types of plane structure and eight types of designed section. They can be combined and designed depending on conditions of each site. The facilities of stormwater storage conduct disaster prevention system and ecological park. Retention pond in stormwater storage facilities for ecological park also should be made for ecological restoration in the site. Third, the ecological park provide the basis for ecological network from in-site to out-site. Therefore its conservation and restoration plan consider the ecosystems of the site. Fourth, the most important factor for maintenance and management for retention pond is keeping water quality. Sustainable Structured wetland Biotop system is suggested for ecological water purification system in the retention pond which is one of the constructed wetland system using multi-celled aquatic plant and pond. This system can also provide habitat for animals and plants, water friendly park for men, and beautiful landscape.

• Journal of the Korean Institute of Rural Architecture
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• v.5 no.3
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• pp.22-33
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• 2003

I recognized necessity of the space planning to three-generation dwelling because of preservation of wholesome society sense of values of the younger generation indicated often to the point at issue by the change to nuclear family of present and by way to hand down thought of respect for the aged which is our traditional public morals. I wish to present basic data for storage space planning that resident's request and consciousness are reflected in such background. I investigated records in general concept, which is utilization pattern of storage space to achieve the function of these culture intermediation. The object of research is three-generation dwelling, such as 3L-K and 3L-DK as national residences that appear most generally in chongju city. The method of research was question investigation method to write utilization actual conditions and requirement of storage space directly. So I proposed suitable planning to resident's life style analyzing frequency, percentage and average distribution. When supply apartment house hereafter, it should be reflected wide selection by resident's characteristic and needed systematic storage space planning in consideration of user mainly. Also continuous and diversified researches that can improve quality of residence are required.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.4
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• pp.717-725
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• 2011

In the power system with an electric storage system that can increase utilization rate of the source of such new renewable energy, this paper introduces the approach on the daily unit commitment scheduling that determines simultaneously optimum operational condition and output of thermal generators and electric storage device. The unit commitment is one of the most important issues in economic operation and security of short-term operational plan of the power system. It is to determine on/off status of generator to minimize operational cost during the given period. The committed generator should satisfy various operational limitation such as estimated demand by system, spinning reserve condition within minimum operational cost. In order to determine on/off or charge/discharge/idle condition and output level of units and electric storage system, the MILP(Mixed Integer Linear Programming) is suggested. The proposed approach is the mixed method between LP(Linear Programming) and IP(integer programming) which seeks the value of real number and integer that maximize or minimize function objective within given condition. The daily unit commitment problem with the electric storage system is applied to MILP algorithm through linearization and formulation process. The proposed approach is applied to the test system.