• Journal of Technology Innovation
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• v.19 no.2
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• pp.153-184
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• 2011

This paper investigates what kind of technological partner firms want to cooperate with in terms of partner location. Two geographical factors are considered. One is geographical proximity, given the tradeoff between the effectiveness of knowledge spillovers in proximity and diverse knowledge absorption from geographically distant partners. The other is how many other firms are co-located with potential partners because it is known that clustering regions can create more technological outputs. Analysis on 2008 Korea Innovation Survey data finds that partner proximity is the single most important factor in choosing a cooperation partner. While firms that are located in a region crowded with related industries prefer proximate partners, others that are surrounded by unrelated industries are more likely to cooperate with distant partners. The findings suggest that geographical proximity matters in partner selection because it not only stimulates knowledge spillovers but also reduces costs involving R&D cooperation such as monitoring costs and information costs. Moreover, firms take into consideration both the benefits and risks of clustering regions. If there are so many unrelated firms that they create agglomeration diseconomies such as congestion costs and unintentional knowledge leakages, firms are more likely to try to find their cooperation partners in other regions.

• Korean Journal of Veterinary Research
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• v.40 no.4
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• pp.719-727
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• 2000

A study was conducted to determine the susceptibility of swine to Korean foot-and-mouth disease virus (FMDV; subtype O, isolated from Chungju province) in April, 2ooo. One holstein cow was inoculated intradermolingually with suspension of homogenized tissue from a Korean native cow naturally infected with Korean FMDY. Infected cow was housed with one susceptible cow and one susceptible pig (contact sentinels). Four additional susceptible pigs were housed in the same room but caged separately (non-contacted sentinels). The contacted pig and cow as well as non-contact pigs developed typical clinical signs after 2, 3, and 7 days post exposure, respectively. We compared neutralizing antibody from the animals to FMDV $O_1$ Lombardy, O Taiwan, $O_1$ Campos, and $O_1$ Manisa after 0, 4, 7, 10, 14, 21, 28 days post challenge and post-exposure. The highest viral neutralization titer could be interpreted that serotype O Korea (Chungju isolate) is antigenically more related to $O_1$ Manisa. In addition, immunohistochemistry was used to further characterize Korean FMDV from tissues of infected pigs. Korean FMDV antigen was observed in the tongue, hoof, esophagus, and tonsil tissues of sentinel pigs. These findings suggest that Korean FMD virus isolated from cattle can be rapidly transmitted to pigs both directly and indirectly contrast field observation in which only cattle were clinically ill.

• Journal of Korea Spatial Information System Society
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• v.8 no.1 s.16
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• pp.93-106
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• 2006

A Grid Database is a database management system to process effectively and use the distributed data in a grid computing environment. Spatial data is more important than other general data according to the local characteristics and requires a large storage. The grid database can be used as the optimal system for the management of the spatial data. However, contrary to the conventional distributed database systems, the Grid Database which guarantees the local autonomy has a possibility not to provide an effective system, or it is impossible to use a centralized management environment. In order to allow flexible responses to a dynamically changing environment, it is required to use effectively reorganized method. In this paper, hierarchical reorganization method is presented for dynamic reorganization in a grid database. When the reorganization is conducted, an organizer is created to collect the information of databases. In addition, the organizer which is constructed by the hierarchical structure supports information communication and reorganization, and then it allows the support of regional reorganization operation and effective balance control. The performance assessment of the proposed method shows that the processing capacity is increased after the reorganization.

• Fire Science and Engineering
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• v.30 no.3
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• pp.31-40
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• 2016

Recently, a curtain wall system was applied to skyscrapers to prevent fire spreading along the vertical direction due to stack effect and outside air flow when a fire breaks out in skyscraper. Conventional sprinklers cannot prevent the spread of fire to the upstairs areas, which increases the loss of life and property. In this study, a water curtain nozzle that creates wider water coverage on the surface of glass and can prevent the spread of fire to the upstairs areas was developed. The spray pattern of the water curtain nozzle was compared with that of a sprinkler to determine performance of the water curtain nozzle. A fire experiment was constructed on the second floor to verify performance of the water curtain nozzle in preventing the spread of fire to the upstairs areas. The fire and watering experiment proved that the water curtain nozzle prevented more effectively the spread of fire than the conventional sprinkler. The position of first crack and critical temperature of fracture were also analyzed using numerical analysis.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.4
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• pp.343-351
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• 2016

Cryogenic spray characteristics of a nitrogen swirl injector operating in supercritical environment have been numerically investigated. By comparing the equation of states(EOS) used for supercritical condition, SRK EOS was applied to predict the nitrogen thermodynamic property under supercritical environment. A Chung's method was implemented for the calculation of viscosity and conductivity and Takahashi's correlation based on Fuller's Theorem was implemented for the calculation of diffusion coefficient. By injecting the nitrogen with 5 bar differential pressure into 50 bar chamber filled with nitrogen, numerical simulation has been conducted. The dynamic Smagorinsky sub-grid scale (SGS) model has been compared with the algebraic Smagorinsky SGS model using FFT frequency analysis. The instability at the liquid film and gas core inside injector and the propagation of pressure oscillation into the injector has been investigated. The spreading angle of swirl injector obtained by numerical calculation has been validated with experimental result.

• Proceedings of the KGS Conference
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• 2002.05a
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• pp.120-123
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• 2002

본 연구는 농천어메니티의 개념을 토대로 농촌주민과 도시민의 가치라고 할 수 있는 정주기능으로서의 생활자원화와 방문가치로서의 관광자원화로 구분하고, 이를 토대로 도시민과 농촌주민, 전문가들을 대상으로 농촌자원의 중요도와 순위적 관계를 분석하였다. 구체적인 연구결과를 살펴보면 다음과 같다. 첫째, 농촌자원을 자연적 자원과 문화적 자원, 사회적 자원으로 구분하여 37개 자원을 설정하였다. 이러한 농촌자원은 농촌어메니티를 형성하거나 형성에 영향을 미치는 대상이라고 볼 수 있다. 둘째, 이러한 농촌자원은 농촌주민과 도시민이 지닌 가치에 기초하여 생활자원적 가치와 관광가치적 가치를 동시에 혹은 차등적으로 지닐 수 있다. 이러한 관점은 농촌자원에 대한 중요도 평균에 대한 차이검증(t-test)을 수행한 결과 전체 자원의 56.8%에 해당하는 21개가 유의미한 차이를 보인 결과에 의해 지지를 받는다. 셋째, 농촌자원에 대한 순위적 상관관계분석에서도 전문가와 전체집단에서 생활자원과 관광자원에 대한 순위상관관계가 의미가 없는 것으로 나타나 위의 두번째 결과를 지지하고 있다. 이러한 결과는 농촌자원의 개발 방향과 가치부여가 자원의 속성에 따라 차등적으로 진행되어져야 함을 보여준다. 다섯째, 농촌자원의 유형을 생활자원화와 관광자원화에 대한 중요도의 표준화 점수에 기초하여 4개 유형(유형 I~IV)으로 구분하였다. 이러한 유형별 자원중요도를 고려하여 농촌마을의 개발목적에 비추어 생활자원형이나 관광자원형과의 연계를 통해 마을의 정체성과 특성화에 기여할 수 있도록 해야 할 것이다.(요약 및 결론에서 발췌)를 고지도와 지리지.읍지를 통하여 살펴봄으로써 변한 것과 변하지 않는 것을 분석하여 시대상의 복원과 지역사회의 정체성 확립에 일조하고자 한다.곡물의 여러 줄기가 합수하고 물이 역류하지 않으며 잘 감아도는 곳으로 표현할 수 있다 이러한 명당의 기본적인 원리는 장풍(藏風)과 득수득파(得水得破)이다. 장풍과 득수란 '국'(局), 즉 산줄기와 수계로 이루어진 일정한 범위 속에 만물이 생태계 속에서 살아가는 모습인 '체형(體形)'의 의미가 나타나야 한다는 것이다. 그러나 이러한 의미는 시대에 따라 달라질 수 있는 것이다.면적의 52%를 점유하여 감자 재배지의 핵심지를 이룬다. 4. 한국 감자 재배지역 중심지의 지리적 특징은, 높은 산지지역의 산록완사면에 밭작물로 재배된다는 점과 교통이 불편한 지역으로서 도시화와 산업화 지역의 그늘 지역이 대부분이다. 강원도의 감자 재배지는 감자재배에 적합한 자연환경과 화전농업의 전통, 감자 재배기술의 전파, 중앙정부와 지방정부가 지원하는 각종 연구소 분포와 영농지도, 씨감자 생산과 협동조합의 판로 개척, 도로 개설과 포장 등의 인문지리적 요인이 영농조건을 개선하고 감자 판매를 위한 시장접근을 용이하게 하여, 남한 최대의 감자 재배지역을 형성하였다. 제주도는 산지지형과 따뜻한 기온으로 2기작이 가능하고, 감자가공 공장설립과 교통발달에 따른 육지 시장과의 접근이 용이해졌기 때문에 남한에서 2번째로 큰 감자재배지역이 되었다.(요약 및 결론에서 발췌)그람양성균에서 효과적이었으며, 농도별 항균력시험 결과 농도가 증가할수록 비례하여 저해율도 증가함을 알 수 있었다. 첨가농도를 달

• Journal of the Mineralogical Society of Korea
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• v.21 no.4
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• pp.435-442
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• 2008

Natural, synthetic, and treated diamonds were studied by NMR and EPR. It was demonstrated that natural and synthetic diamonds, treated and non-treated diamonds, high pressure high temperature (HPHT) treated and electron beam treated diamonds could be distinguished among each other based on the $^{13}C$ NMR spectra acquired for relatively short periods of 100 minutes. The $^{13}C$ NMR linewidths of gem quality synthetic diamonds were broader than 1.6 ppm due to the paramagentic effects of transition metals, generally used as catalysts, while the linewidths of gem quality natural diamonds were narrower than 0.5 ppm regardless of the methods of treatment. The linewidth (0.5 ppm) for a HPHT treated, gem quality natural diamond was as broad as more than twice of the linewidth (0.2 ppm) of an electron beam treated diamond. The $^{13}C$ NMR signal intensities of treated, gem quality natural diamonds were as strong as more than 10 times of the intensities of non-treated, gem quality natural diamonds. When correlated with the concentrations of the paramagnetic defects (electrons) obtained from the EPR spectra, the relative $^{13}C$ NMR signal intensities increased in proportion to the concentrations of the paramagnetic electrons contained in each sample but the electron beam treated diamond was an exception. This suggested that the lattice component, in addition to the paramagnetic defect component, should also be considered in determining the $^{13}C$ NMR signal intensity of the electron beam treated diamond.

• Journal of Distribution Research
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• v.13 no.3
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• pp.101-125
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• 2008

This research suggests an ideal role between franchisee and franchisee for survival and development of the Korean franchise business by identifying causal relationships between entrepreneurship of franchisees and their business performance. Besides, when considering multi-dimensional features of a franchise system, this study aims to show that the market orientation of the franchisee and the relationship commitment between franchisee and franchisee will play an important mediating role to achieve a better business performance. Thus specific causal relationships among sub-dimensional constructs of entrepreneurship and market orientations were investigated. They are innovativeness, risk-taking propensity, pro-activeness, information creation, intelligence generation, intelligence dissemination, response design, response implementation. The results demonstrate that pro-activeness of franchisee plays a crucial role for franchisee's business performance. It was noted that franchisor's market orientation and innovativeness is also important for high market orientation of franchisor. The higher the market orientation of franchisor was, the higher relationship commitment of franchisee was formed. By identifying the mediation effect of relationship commitment and market orientation of franchisor, this paper showed that relationship commitment positively affect the improvement of franchisee's business performance. Above all, it should be noted that this research empirically identified the relationship between franchisee's entrepreneurship and business performance that most of the previous researchers have ignored. Furthermore, the analysis was conducted at sub-dimensional construct level. It is expected that empirical results from this study will be able to provide a meaningful framework and theoretical basis for future research on franchise, entrepreneurship and market orientation.

• Geophysics and Geophysical Exploration
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• v.9 no.3
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• pp.241-249
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• 2006

Due to the long tectonic history and the very complex geologic formations in Korea, the anisotropic characteristics of subsurface material may often change very greatly and locally. The algorithms commonly used, however, may not give sufficiently precise computational results of traveltime data particularly for the complex and strong anisotropic model, since they are based on the two-dimensional (2D) earth and/or weak anisotropy assumptions. This study is intended to develope a three-dimensional (3D) modeling algorithm to precisely calculate the first arrival time in the complex anisotropic media. Considering the complex geology of Korea, we assume 3D TTI (tilted transversely isotropy) medium having the arbitrary symmetry axis. The algorithm includes the 2D non-linear interpolation scheme to calculate the traveltimes inside the grid and the 3D traveltime mapping to fill the 3D model with first arrival times. The weak anisotropy assumption, moreover, can be overcome through devising a numerical approach of the steepest descent method in the calculation of minimum traveltime, instead of using approximate solution. The performance of the algorithm developed in this study is demonstrated by the comparison of the analytic and numerical solutions for the homogeneous anisotropic earth as well as through the numerical experiment for the two layer model whose anisotropic properties are greatly different each other. We expect that the developed modeling algorithm can be used in the development of processing and inversion schemes of seismic data acquired in strongly anisotropic environment, such as migration, velocity analysis, cross-well tomography and so on.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.4
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• pp.651-658
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• 2001

A novel multi-section power divider configuration is proposed to obtain wide-band frequency performance up to microwave frequency region. Design procedures for the proposed microwave broadband power divider are composed of a planar multi-section three-ports hybrid and a waveguide transformer design procedures. The multi-section power divider is based on design theory of the optimum quarter-wave transformer. Furthermore, in order to obtain the broadband isolation performance between the two adjacent output ports, the odd mode equivalent circuit should be matched by using the lossy element such as resistor. The derived design formula for calculating these odd mode matching elements is based on the singly terminated filter design theory. The waveguide transformer section is designed to suppress the propagation of the higher order modes such as waveguide modes due to employing the metallic electric wall. Thus, each section of the designed waveguide transformer should be operated with evanescent mode over the whole design frequency band of the proposed microwave broadband power divider. This paper presents several simulations and experimental results of multi-section power divider to show validity of the proposed microwave broadband power divider configuration. Simulation and experiment show excellent performance of multi section power divider.