• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.54-60
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• 2004

With the proliferation of nonlinear loads such as commercial facilities in all of modern society high neutral harmonic currents have been observed. High neutral currents in three-phase four-wire distribution systems can cause lots of harmonic problems. The most common solution of neutral harmonic currents reduction is a zero phase sequence filter using zig-zag transformer. This paper analyzes a commercially available neutral line zero sequence currents reduction device and applies the equipment to commercial office loads for eliminating harmonics. Experimental results m compared numerically and graphically with simulation results through the use of MATLAB.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.8 no.2
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• pp.61-69
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• 2012

Geothermal heat pump(GHP) systems have been shown to be an environmentally-friendly, efficient alternative to traditional cooling and heating systems in both residential and commercial applications. Although some experimental work related to performance evaluation of GHP systems with vertical borehole ground heat exchangers for commercial buildings has been done, relatively little has been reported on the performance simulation of these systems. The aim of this study is to evaluate the cooling and heating performance of the GHP system with 30 borehole ground heat exchangers applied to an commercial building($1,210m^2$) in Seoul. For this purpose, a typical design procedure was involved with a combination of design parameters such as building loads, heat pump capacity, circulating pump, borehole diameter, and ground effective thermal properties, etc. The cooling and heating performance prediction of the system was conducted with different prediction methods and then each result is compared.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.10
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• pp.999-1006
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• 2004

Recently, the ride comfort problem becomes increasingly important because of today's needs for train speedup. The railway has the track irregularities which cause vibrations, such as rail joints, turnout, level crossing, transition corves and super-elevation ramps, and variations in the track level(z-axis) and the gauge(y-axis). In Korea, the service run of the high speed train has been made since the 1st of April, 2004. The commercial high-speed trains must be run on the compound lines which are composed of high-speed line and conventional line. The high speed lines in both Kyoungbu line and Honam line have 57.5％ and 33.8％, respectively In this Paper, the ride comfort has been reviewed by the various experimental methods when the high-speed trains are operated on both Kyoungbu line and Honam line. The results show that the high-speed train has no problems from the viewpoint of the comfort ride during the operation on the high speed line and conventional line.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.206-211
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• 2004

Recently, the ride comfort problem becomes increasingly important because of today's needs for train speedup. The concept of ride comfort is equivocal. Generally, it is defined as the body vibration. The commercial high-speed train must be run the compound line in Korea which is composed of high-speed line and conventional line. In this paper, the ride comfort has been reviewed by the various experimental methods when the high-speed train is operated on both lines. The results show that the high-speed train has no problems from the viewpoint of the comfort ride during the operation on both lines.

• Progress in Superconductivity and Cryogenics
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• v.2 no.2
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• pp.20-25
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• 2000

A CICC type superconducting bus-line electrically connecting a superconducting magnet to a power supply is cooled down to low temperature under the external magnetic field during operation. The thermal contraction during the cooling may be constrained by the supports which are installed to protect the bus-line from Lorenz magnetic forces. This constrained contraction causes thermal stresses in the bus-line to release thermal contraction. The minimum stress conditions in the bus-line may be optimized by controlling the supporting arrangement considering the thermal contraction and the external field. The analytical method to find optimal supports arrangement was suggested by using the beam theory, and numerical calculation using commercial code was performed to verify the suggested analytical optimization method.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.199-201
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• 2003

Because of Korean power system characteristics and increasing power demand, the need of 765kV transmission line is growing gradually. Now a days, KEPCO's 765kV transmission line has been tested and stands for commercial operation. During the first stage, 765kV transmission line will be operated with two voltage grades of 765kV and 345kV, which results the unbalance of power system. So unbalanced current such as zero sequence current flows in the transmission line. In this paper, we describes the simulation study of 765/345kV parallel transmission line by using EMTDC program.

• Korean Institute of Interior Design Journal
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• v.23 no.4
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• pp.211-219
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• 2014

The internal streets of mixed-use commercial complexes, which are the extension of urban streets, are being changed from a mediating space aiming at movement to a staying-type space according to the change of mixed-use commercial complexes. And they function as a resting place of user with court and plaza, and act as an urban public space, and accommodate an activity arising from the gathering of many people. As a result, a role of new relaxation and community space is played in the center of the city. And the aspect of publicness is brought into relief. Hence, this study is intended to examine the characteristics that the internal streets of mixed-use commercial complexes have, and furthermore, it is intended to show the planning characteristics in the contemporary mixed-use commercial complexes. With regard to the method of research, first, space configuration and role of internal streets was examined according to the change of mixed-use commercial complexes on the basic of precedent research and literature review. And the internal streets of mixed-use commercial complexes were classified into doorway part, traffic line, and open space. And the characteristics of internal streets in the mixed-use commercial complexes through the concept of architectural 'publicness' were derived as accessibility, amenity, perceptibility, openness, connectivity and symbolism. The internal streets of mixed-use commercial complexes should be changed by the space planning to secure continuity with the city on the basis of accessibility and connectivity and to reinforce visual openness in the internal streets in order to improve amenity and perceptibility, accordingly the mixed-use commercial complexes will be also born again as symbolic public space in the city. Variously changing elements to improve publicness very importantly act on the planning of internal streets in the mixed-use commercial complexes, and therefore researches should be continuously carried out.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.187-193
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• 2010

This paper introduces a new mobile advertisement management system (AMS) utilizing on-line music service in communication networks. The developed AMS delivers commercial advertisement through music service that is preferred in communication networks, which enable advertisers to perform a customer based advertisement and listeners to get a discount on their bills for music service. And eventually the proposed AMS can provide the effective commercial service to the advertisers and the effective clients recruit ways to music providers.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.6
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• pp.377-383
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• 2015

Torsion mode or bending mode of drive-line for rear-wheel drive vehicle exists in low frequency band. If resonance exists there between natural mode of driveline and powertrain excitation force, drive-line will manifest excessive vibration response. Also, the vibration response can be transmitted to vehicle body and can induce booming noise. A vehicle in this study exhibits a booming noise problem under specific transmission gear condition. To draw performance improvement plan, finite element analysis technique was used. Modification was evaluated qualitatively and priorities were derived. Finally, effectiveness of best modification was verified through test and full vehicle FE analysis.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.1
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• pp.57-62
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• 2003

An effort was made to assess comparative production performance in broiler chickens fed diets containing solvent extracted cottonseed meal (CSM) processed from BT and Parental Non-BT lines. Processed meal of national check and commercial produce cottonseeds were also used for comparison. The free gossypol contents were 0.02, 0.02, 0.44 and 0.03% in meals of BT, Parental Non-BT, national check and commercial produce cottonseeds, respectively. Day-old broiler chicks (n=243) were divided to 27 groups of 9 each. Nine dietary treatments (iso-nitrogenous, 23% CP and iso-caloric, 2,800 kcal ME/kg) were formulated viz., D1 (control, soybean meal-SBM based), D2 and D3 (BT CSM at 10% of diet with and without additional iron), D4 and D5 (non-BT CSM with and without additional iron), D6 and D7 (national check CSM with or without additional iron), and D8 and D9 (commercial produce CSM with or without additional iron at 2 ppm for every 1 ppm of free gossypol, respectively). Each dietary treatment was offered to three replicated groups up to 6 weeks of age. At the end of 6 weeks of age, 10 birds were taken out randomly from each treatment and were sacrificed to study carcass traits, organs' yield and histo-pathological changes in vital organs. The broiler chickens received CSM processed from BT (D2, 1,753 g and D3, 1,638 g) and Parental Non-BT (D4, 1,653 g and D5, 1,687 g) with or without additional Fe grew at same rate as observed in soybean meal (solvent ext.) based diet (D1, 1,676 g). The feed intake and feed conversion efficiency (feed: gain) in these dietary treatments (BT, non-BT line based diets) also did not differ significantly (p>0.05) from control diet. Similar observation was also observed in dietary treatments (D8 and D9) containing solvent extracted cottonseed meal of commercial produce origin. However, a decrease (p<0.05) in body weight gain and feed intake was observed in D6 containing national check CSM with high gossypol content. Addition of Fe in the diet (D7) improved (p<0.05) feed intake and weight gain but not to the extent as observed in diets containing BT, parental non-BT, and commercial produce CSM or control. However, any type of CSM did not affect feed conversion efficiency when fed with or without additional iron. The carcass characteristics in terms of dressing percentage, liver weight and heart weight was not significantly (p>0.05) different between the treatments. The eviscerated yields emanated from diets containing either BT, non-BT or commercial produce were statistically similar to control. However, eviscerated yield of broilers fed national check CSM with or without iron supplementation was lower (p<0.05) than BT cotton with Fe supplementation and commercial produce CSM. The study envisaged that BT, parental non-BT and commercial produce solvent extracted cottonseed meal can be included at 10% in soybean meal based broiler diet replacing soybean meal and rice bran without additional iron.