• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.3
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• pp.711-721
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• 2014

PPWS, a large number of which a main cable of a suspension bridge consists of, must be precisely erected at a target location under construction considering the differences among design conditions. The absolute sag is measured for several PPWSs, which are reference strands and the relative sag is surveyed from them to other PPWSs, which are divided into several groups. And the adjustment of PPWS length is performed to erect it at target configuration. When PPWS is being under erection in a real bridge site, the procedures are as follows; evaluate sag sensitivities according to sag variation factors, calculate an adjustment length of PPWS corresponding to them and adjust a sag of PPWS by controlling the calculated amount of PPWS length. In this study, the differential-related equations of sag sensitivity were proposed for support movement of PPWS. Before site demonstration study of a series of them, we established a catenary model system and accomplished verification tests of them. From test results, the validation of them was done.

• Journal of Distribution Research
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• v.12 no.1
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• pp.105-123
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• 2007

Recently, the beauty service industry in Korea is growing rapidly as women have increased role in society and consumers have more diversified desire for beauty. In that sense, studies on the environment of transaction is necessary to maintain the customers who use beauty service which Is one of the most prominent services in Korea. However, there is a lack of systematic investigation on that. Under those circumstances, this study tries to propose strategies by shedding light on the reasons of store loyalty based on empirical study. Furthermore, securing regular customers is deemed to be the most important thing as the competition among stores are getting fiercer in the wake of increase in the number of beauty salons. In that light, this study tries to shed light on the transaction cost clearly which affects the store loyalty, and focuses on the development of integrated research model for the transaction cost related to the environmental characteristics of beauty service industry and for the store loyalty.

• Tunnel and Underground Space
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• v.25 no.6
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• pp.527-533
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• 2015

This study performed an on-site demonstration of the topographic surveying technique at a large-scale open-pit limestone mine in Korea using a fixed-wing unmanned aerial vehicle (UAV, Drone, SenseFly eBee). 288 sheets of aerial photos were taken by an automatic flight for 30 minutes under conditions of 300 m altitude and 12 m/s speed. Except for 37 aerial photos in which no keypoint was detected, 251 aerial photos were utilized for data processing including correction and matching, then an orthomosaic image and digital surface model with 7 cm grid spacing could be generated. A comparison of the X, Y, Z-coordinates of 4 ground control points measured by differential global positioning system and those determined by fixed-wing UAV photogrammetry revealed that the root mean squared errors were around 15 cm. Because the fixed-wing UAV has relatively longer flight time and larger coverage area than rotary-wing UAVs, it can be effectively utilized in large-scale open-pit mines as a topographic surveying tool.

• Applied Biological Chemistry
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• v.6
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• pp.33-36
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• 1965

1. The extraction of securine, an alkaloid, from Securinega suffruticosa Rehder growing in Korea was investigated. 2. The distribution of the source plant in Korea is considered to be most intense among the Fareast countries. 3. The extracted material was identified to be genuine securinine viewing from melting point and microscopic observation. 4. The yield of the substance in this study was 0.075% in average. The less amount of recovery may be due to the collection of the plant in October instead of that in the prime season. 5. There should be more efficient way in the separation of resinous impurities from the crude product. Application of Chromatographic technique and selection of more efficient solvent will be investigated hereafter.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.475-478
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• 2001

Currently, in spite of continual efforts the information utility of construction industry has low-efficiency for the other industry. These problems arose from the erroneous efforts for the information utility of construction industry. Because it left out of consideration of the construction characters, which are the center of construction sites, and this information system was directly introduced and operated from the other industry. Also, we can point out mistake that the existing information systems disregarded using facility in the fixing of these problems. Therefore, this study describes a new process, which purposes to build and utilize construction information management system as using Personal Digital Assistant (PDA) of the mobile communication concept, to solve the problems of existing construction information management system.

• Polymer(Korea)
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• v.35 no.5
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• pp.451-457
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• 2011

The effect of latex particle size on rheological and electrical properties of latex-blended polystyrene (PS)/multi-walled carbon nanotube (MWCNT) nanocomposites was investigated. Mono-dispersed PS particles synthesized either by emulsifier-free emulsion polymerization or by dispersion polymerization were mixed with MWCNTs under ultrasonication, and freeze-dried to prepare the nanocomposites. As the MWCNT content increased, storage modulus, complex viscosity and electrical conductivity were substantially increased. The increase of storage modulus and complex viscosity was higher for larger PS particles. The effect of particle size on electrical properties was different depending on MWCNT content. With lower MWCNT content, the nanocomposite prepared by smaller PS particles showed higher electrical conductivity, but the opposite result was given as the content increased.

• Journal of Digital Convergence
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• v.14 no.9
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• pp.1-7
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• 2016

In recent years, the importance of collaboration has been emphasized in the public sector as well as private companies. In a study for private enterprises, individual enterprises stressed the innovation through collaboration with other organization such as enterprise, university, and other agencies. Other companies and agencies have the technology they need, so that they share skill or knowledge, and they do to create more new developments. This implies a collaborative system can be a win-win collaboration with all partners. It also requires collaboration in the public sector. Because they have many problems that can not be solved at the level of individual institutions. However, public institutions lie ecologically unfavorable in a collaborative environment than the private sector. The organizational structure is hierarchical. In addition, relationships between collaboration partners not recognize horizontally. Of course, communication is not smooth. This study examines successful collaboration case in private sector and we want to draw implications for public organizations. Finally, we discussed ways to promote collaboration in the public sector.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.4
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• pp.54-63
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• 2013

In this paper, we evaluate the accuracy of the vertical positioning by distance using Network RTK-GPS. The experimental results confirm that Network RTK-GPS method can acquire data quickly and accurately than conventional leveling methods so that the Network RTK-GPS method is a relatively efficient and economical way for the vertical positioning. Results of validation using permanent GPS stations indicate that visible satellites, PDOP, and VDOP are very good for the vertical positioning. Integrated reference points such as U0997 and U0921 are satisfied with 3 ratings in the rules of public leveling and all the rest are proved improper. When the vertical positioning using Network RTK-GPS is implemented, the geoid height of EGM2008 should be applied for leveling. If the number of geodetic satellite are increasing in the near future, the vertical positioning using Network RTK-GPS can be possible in all the range.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.795-796
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• 2010

Interest has been increasing worldwide in Fischer-Tropsch synthesis (F-T) as a method of producing synthetic liquid fuels from biomass. Hydroisomerization of $C_7-C_{15}$ paraffins applies to production of diesel fuel with high cetane number and improved cold flow properties, such as viscosity, pour point and freezing point. The commercial products such as fuel jet produced from F-T synthesis should have low freezing and pour points. In this study, our major aim is to develop a catalyst for hydroisomerization of synthesis-oil for bio-jet fuel. Effects of zeolites and platinum loading on hydroisomerization of dodecane were investigated as a model reaction in a batch reactor.

• Journal of Digital Convergence
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• v.10 no.7
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• pp.69-75
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• 2012

This study aims to suggest the amendment method of publishing bulletins for election in accordance with the changed consciousness of voters and the environment of times after examining the expression strategies of a candidate's message through the analysis of publishing bulletins of local election in 2010. Accordingly, it tries to indicate the strategies of publishing bulletins for election more easily and briefly. As to the description of expression strategies, there were a lot of rational descriptions and positive appeals with the perspective of a third person. It shows the awareness that aggressive and negative expression brings about adverse effects. The appeals of the cover slogan in campaign promises were in the sequence of the candidate's character, regional development, and social welfare, and most campaign promises were within the range of ten promises. The most used symbol of candidates was the party which candidates belong to. The main empathized contents include the name of candidates, the experience of candidates, management, political ability, and region. In addition, slogans had the intention to express folksy and intimacy by raising the rates of residents' emergence.