• 한국해양학회지
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• v.27 no.2
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• pp.145-153
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• 1992

From the analyses of 16 bottom sediment samples and current data obtained during field expert ments from August to September 1987, the textural characteristics and transport mode of sand grains of a tidal sand ridge in Gyeonggi Bay are studied. The textural characteristic of the bottom sediments are diverse depending on their location on the tidal sand ridge. Sands on the crest are well sorted. near symmetric in skewness. leptokurtic in kurtosis. and are unimodal in peakedness. On the other hand, Poorly sorted gravelly sands in the trough are coarse skewed in skewness and plartkurtic in kurtosis. The mean values of U/SUB 100/ (velocity at one meter above bottom) and U/SUP */ (boundary shear velocity) are calculated to be 41.4 cm/sec and 2.39 cm/sec, respectively. From the analyses of characteristics of the sediments and currents in the study area, it can be concluded that almost all the sands of the tidal sand ridge (esp. on the crest) are transported as bedload (mainly as saltation).

• 한국해양학회지
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• v.30 no.3
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• pp.203-215
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• 1995

Two hydrographic surveys along with direct current measurements using drogues and moored current meters were conducted in Cheju Strait during April and May, 1983. The data clearly demonstrate that a branch of the Kuroshio characterized by high temperature and high salinity enters the Cheju Strait after turning around the western coast of Cheju-Do. The width of the current turning west of Cheju-Do is about 60 km and reduces to 20∼30 km in the strait, resulting in a high speed(＞10 cm/s) at the western entrance and in the middle of the strait, compared with a low speed (＞5 cm/s) west of Cheju-Do. The Tsushima Current water also originating from the Kuroshio shows its influence in the eastern part of the Cheju Strait. Thermohaline fronts formed between the warm current waters and the coastal waters suggest the southward extension of the Yellow Sea Coastal Water west of the Cheju Strait. A warming of the warm current waters occurs in May, while a cooling takes place in other areas. The major freshening and cooling of water take place in the middle of the Cheju Strait in May due to the intrusion of cold and low salinity water from the west of the Cheju Strait.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.4
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• pp.383-391
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• 2011

The hot-stamping technique is used to manufacture high-strength parts by press forming by heating at a temperature above the Austenite transformation temperature and then rapid cooling. Boron steel, which contains a very small amount of boron, is one of the materials used for hot stamping. The purpose of this study is to show the microstructures and to investigate the mechanical properties under different heat-treatment conditions. The heat treatment of water quenching was conducted at the various temperatures and different elapsed times. These can be practical data useful when boron steels are used for hot stamping. Furthermore, the microstructures and mechanical properties of the spot-welded specimen with coatings and counterpart materials (SPRC 340, SPRC 590) is investigated in order to determine the welding characteristics of boron steel at different welding condition.

• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.185-194
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• 1999

The purpose of the study is to examine the relation between 'Miruk-ri Bongsan Stone Landmark' found in 1997 and 'Moonkyung County Bonsan' and Choryung Bongsan. Relevant literature was analyzed and the spots were investigated as well. Data used are geography book, maps, town chronicles and the Annals of the Chosun Dynasty in the late period of the Chosun Dynasty. The major findings are as follows ; (1)'Miruk-ri Bongsan Stone Landmark' is inferred as Stone Landmark of Choryung Bongsan. (2)Choryung Bongsan was designated to protect a strategic forest lands established around the Choryung Pass for the defence of Chungju which is the door of Capital city, Hanyang, and connected to South Han River. (3)'Miruk-ri Bongsan Stone Landmark' seems to be erected at Miruk-ri because it was a spot of traffic importance, which connects among Choryung, Moonkyung County and Chungju County in notifying the importance of Bongsan to travelers.

• Journal of Fashion Business
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• v.8 no.5
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• pp.41-59
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• 2004

The purpose of this study is to analyze consumers' purchase behavior for the counterfeits of fashion luxury brands. The research method of the study used a naturalistic approach. The first participant observation was carried out in the internet sites in order to collect the data on the purchase behavior for counterfeits; and the second participant observation was applied in the Dongdaemun shopping mall, Namdaemun shopping mall and Itaewon shopping mall; finally 6 informants were selected and then an interview was held with them. The results of the study are as follows; 1. The reasons for the first purchase of counterfeits are variously shown according to life stages, and the repetitive purchase behavior is influenced by the degree of satisfaction for the first purchase. The information collection for counterfeits is widely made through various media, and especially the information collection is active and positive in the case of planned purchase but it is passive and negative in the case of unplanned purchase. 2. The most important criteria in purchasing counterfeits is the degree of similarity with luxury brands and other criteria include price, design, utility etc. The majority of purchase items is not clothing but miscellaneous goods which are more similar in terms of design and quality. The purchase of counterfeits is made by impulse purchase but the purchase of luxury brands is made by planned purchase. 3. The rationalization mechanism for the purchase of counterfeits is observed in all informants, which is a sort of defence mechanism for avoiding a guilty conscience to buy illegal goods.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.3
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• pp.282-287
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• 2015

In modern warfare, the importance of SEAD(Suppression of Enemy Air Defense) mission is being emphasized. However, this mission runs the risk of hull damage or casualties of our friendly air forces. Because of these risks, research on the way of minimizing damages and enhancing mission capability is under active discussion. As a part of this research, SEAD mission planning with multiple UAVs has been covered using vector field guidance. This guidance method not only applies to various forms of flight path but also requires less computational power than other guidance methods. Therefore, in this paper, planning methods of SEAD mission for multiple UAVs using vector field guidance and experimental data from flight experiments regarding designed mission has been covered.

• Convergence Security Journal
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• v.13 no.1
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• pp.37-43
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• 2013

In 2010, the Ministry of National Defense decided to build a MegaCenter including the cloud computing technology by 2014, as part of the '2012 Information Service Plan', which is now underway. The Cloud computing system environment should be designed applying cloud computing technology and policy for an efficient infrastructure that many IT resources are available in the data center as a concentrated form. That is, the system should be designed in such a way that clouding services will be efficiently provided to meet the needs of users and there will not be unnecessary waste of resources. However, in order to build an optimal system, it should be possible to predict the service performance and the resource availability at the initial phase of system design. In this paper, using the CloudAnalyst simulator to predict availability of the K-defence cloud computing system service, conducts cloud modeling and analysis of the 'Facebook', one of the most famous social network service applications with most users in the world. An Optimal K-Defense cloud computing design model is proposed through simulation results.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.12
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• pp.1315-1320
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• 2015

In this paper Communication data link equipment on a high speed-hopping method to use the frequency resources efficiently for the frequency environment is introduced such as sensing techniques, using the same frequency band by using the received two-channel technique and the receive filter bank unit applied to be shared with other equipment such as radar and so on. The real-time measurement and analysis were operated for measurement the frequency environment of the operating band in advance. and primarily equipment to develop is analyzed how the interference effect to the radar minimize the operation of radar equipment. In reverse, to use the same frequency band the methods such as frequency sharing techniques are presented in this paper. Finally, by design of the main items of the RF transceiver NF, transmission output, and a simulation of the IMD, such as whether the key is verified prior to meet specifications.

• Journal of architectural history
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• v.19 no.6
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• pp.7-22
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• 2010

This study includes a review of the relevant literature and data on the Gyeolseong Eupseong, a coastal castle town of the Joseon Period. During the process of building the Gyeolseong Eupseong, Eupchi(administrative office) was transferred to several different locations for the following reasons:. first, to strengthen defensive capabilities by utilizing the locational advantages of the Seokdang Mountain Fortress, second, to secure sufficient space for holding the castle and have access to water in times of emergencies, third, to strengthen coastal defence by utilizing geographical advantages. Most of the Gyeolseong Eupseong was damaged during the Japanese colonial period. At present, there remain only part of the castle's facilities and some facilities that were restored later in modern times; 4 building sites have been identified. Remaining and destructed buildings can be identified through old maps(the local maps of 1872) and Zirizi and Eupzi(geography books). Also identified were 2 castle gate sites where a 1,500m-long stone castle wall and an ongseong(a crescent-shaped defensive structure), 5 chiseongs, and a most were constructed. The Gyeolseong area is assumed to have been a strategic foothold to defend the west coast from the days before the Three Kingdom Period. However it is very difficult to find any records created before the Joseon Period. Therefore, the time of the restoration of the Eupchi should be determined based on records created in the late Joseon Period. Finally, excavation work needs to be done to identify the locations of the castle's facilities.

• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.6
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• pp.19-27
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• 2017

This study investigated to predict the compressive strength of unsaturated polyester resin based polymer concrete using the maturity method. The test results show that the development of the compressive strength increased exponentially until an age of 24 hours. After 24 hours, the development of the compressive strength just increased gradually. This test result shows that the strength of unsaturated polyester resin based polymer concrete was developed mainly at the early age. Estimated datum temperature of unsaturated polyester resin based polymer concrete was $-20.67^{\circ}C$ which was much lower than of datum temperature ($-10^{\circ}C$) of Portland cement concrete. Also, this study result shows that the existing maturity index associated with Portland cement concrete was not applicable for polymer concrete because curing time of Portland cement concrete is different clearly with curing time of polymer concrete. The cause of different curing time was that there were different curing mechanisms between Portland cement concrete and polymer concrete. In order to best apply the experimental data to a model, CurveExpert Professional, the commercial software, was used to determine the predictive model regarding the compressive strength of unsaturated polyester resin based polymer concrete. As a result, Gompertz Relation or Weibull Model was an appropriate model as a predictive model. The proposed model can be used to predict the compressive strength, especially, it is more useful when the maturity is in the range between $40^{\circ}C{\cdot}h^{0.4}$ and $900^{\circ}C{\cdot}h^{0.4}$.