• Journal of Digital Convergence
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• v.10 no.2
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• pp.25-36
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• 2012

Over the last few years, despite the government's ongoing efforts for cooperative relationship between large firms and small and medium-sized enterprises(SMEs), their effectiveness is limited. In addition, the academic researches for addressing practical policy alternatives are also insufficient. This study aims to suggest the practical policies for cooperative relationship between large firms and SMEs. To this end, we suggest typology to know how collaboration process between large firms and SMEs for technology commercialization project with the utilization of dimensions of technology and marketing cooperaton is, and analyse the characteristics of each type, and examine the present situation of collaboration between large firms and SMEs in Korea and then finally, derive government policy guidelines. Through this research, we suggest theoretical framework to reinforce national industry competitiveness under growing global competition through suggesting how SMEs take survival basis, and also how large firms collaborate with SMEs.

• The Journal of the Acoustical Society of Korea
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• v.33 no.4
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• pp.232-237
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• 2014

A passive sonar of warship is composed of several directional or omni-directional sensors. In order to model the acoustic signal received into a warship sonar, the wave propagation modeling is usually required from arbitrary noise source to all sensors equipped to the sonar. However, the full calculation for all sensors is time-consuming and the performance of sonar simulator deteriorates. In this study, we suggest an asymptotic method to estimate the sonar signal arrived to sensors adjacent to the reference sensor, where it is assumed that all information of eigenrays is known. This method is developed using Taylor series for the time delay of eigenray and similar to Fraunhofer and Fresnel approximation for sonar aperture. To validate the proposed method, some numerical experiments are performed for the passive sonar. The approximation when the second-order term is kept is vastly superior. In addition, the error criterion for each approximation is provided with a practical example.

• The Journal of the Acoustical Society of Korea
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• v.32 no.4
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• pp.301-307
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• 2013

SONAR detection performance is one of the key survivability factors in underwater weapon systems. In order to catch the acoustic ability of SONAR, multilayer SONAR structures are analyzed using the elastic theory. The applied results for the simple models are compared with those from commercial program, ANSYS, and the reliable results are obtained. The analysis of sound pressure level (SPL) and echo reduction (ER) by the thickness change of multilayer SONAR structures are performed using the verified elastic theory. As the thickness of anechoic layer is increased, SPL is distributed evenly and ER is increased slightly with the frequency. In decoupling layers and steel layers, SPL are hardly changed and ER is slightly decreased with the thickness increase of those layers. SPL and ER are not affected by the thickness change of the carbon reinforced plastic (CRP) layer. Therefore, to improve the acoustic ability of multilayer SONAR structures, the thickness increase of the anechoic layer and minimization of the decoupling layer, steel layer and CRP layer are desirable.

• Korean Journal of Ichthyology
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• v.21 no.3
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• pp.141-148
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• 2009

Sex differentiation and gonad development were investigated in a marine medaka species, Oryzias dancena (Beloniformes; Teleostei). The average time to hatch was 11 days post-fertilization (dpf) at $25^{\circ}C$. Primordial germ cell (PGC) was first observed at 5 dpf and migrated to presumptive gonadal area between the gut and pronephric duct at 9 dpf. Male and female gonads were morphologically differentiated at 12 days post-hatching (dph). Early oocytes at perinucleolus stage as well as the formation of spermatid and efferent duct were observed at 28 dph. At 6 weeks of age, the ovary exhibited yolk granulation in many oocytes, while testis possessed a considerable number of spermatogonia and spermatids. The first ovulation was observed in 9-week-old females, and at the same age, males contained fully-matured spermatozoa. Data obtained in this study indicate that the gonad differentiation of O. dancena is the typical type of differentiated gonochorism.

• Analytical Science and Technology
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• v.28 no.6
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• pp.446-452
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• 2015

In order to evaluate and improve the ability of Korean testing laboratories to measure Polybrominated diphenyl ethers in acrylonitrile-butadiene-styrene (ABS), a proficiency test was organised by Korea Research Institute of Standards and Science (KRISS) based on ISO/IEC 17043. The proficiency test material used was 10 g of a granular ABS fortified with a mixture of congeners of PBDE (BDE-154, 183, 206, 209). Homogeneity and stability were investigated to assess the adequacy of the test material. The certified value established by KRISS based on the national reference was used for assigned value of each PBDE. The test materials were distributed to the 16 participating laboratories. The participating laboratories were requested to analyse the samples employing the methods used in their routine analysis. Each laboratory was given it’s own code to secure the anonymity. Participants results were evaluated with z-scores according to ISO/IEC 17043. The standard deviation for proficiency assessment was set by standard deviation of the participants results except for outlier. The results, the laboratory's performance and improvement of accuracy were discussed.

• The Korean Journal of Financial Studies
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• v.12 no.1
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• pp.127-161
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• 2006

본 연구는 미국과 유럽의 채권 전자거래에 대한 제도를 분석한 후, 우리나라의 채권 전자거래에 대해 시사점을 제시하고자 한다. 본 연구의 결과는 다음과 같이 요약된다. 첫째, 미국과 유럽에선 채권 전자거래 시스템(Electronic Trading System, 이하 ETS)의 영업행위가 원칙적으로 증권 중개업의 관점에서 규제된다. 이러한 방향의 규제 체계는 다양한 형태의 채권 ETS가 등장할 수 있도록 하여 채권시장의 발전에 기여한다. 둘째, 우리나라의 $\ulcorner$한국증권선물거래소법$\lrcorner$ 15조 2항 및 $\ulcorner$증권거래법시행령$\lrcorner$ 84조의27 6항은 다양한 형태의 채권 ETS의 등장을 원천적으로 봉쇄함으로써 채권시장의 발전을 저해하고 있다. 셋째, 현행 $\ulcorner$한국증권선물거래소법$\lrcorner$ 15조 2항은 주식 및 선물거래에 대해서 계속 적용하되 채권거래에 대해서는 그 적용이 유보될 필요가 있다. 이를 통하여 $\ulcorner$한국증권선물거래소법$\lrcorner$은 주식시장을 활성화 시키는 순기능을 유지하면서 채권 ETS의 등장을 원천적으로 봉쇄하는 역기능을 피할 수 있다. 넷째, $\ulcorner$한국증권선물거래소법$\lrcorner$ 15조 2항이 채권거래에 대해서 적용되지 않는다면, $\ulcorner$증권거래법시행령$\lrcorner$ 84조의27 6항은 삭제되어야 하며, 대신에 증권거래법은 채권 ETS의 활동 범위와 요건을 정의해 주어야 한다. 채권 ETS의 활동은 원칙적으로 증권업자의 중개활동으로 간주되어야 한다. 채권 ETS의 중개 규모가 일정 수준을 넘어설 경우 거래소에 준하는 보고, 공시 및 감시 요건이 부과되는 것이 바람직하다. 다섯째, 채권시장의 효율성을 강화하기 위해서 채권 ETS에 대해서 적용되는 투명성 강화, 시장분할 방지, 공정거래 등에 대한 규제는 거래 대상의 특성에 따라서 탄력적으로 조정될 수 있어야 한다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.6
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• pp.381-387
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• 2017

Dehydrogenation from the hydrolysis of a sodium borohydride ($NaBH_4$) solution has been of interest owing to its high theoretical hydrogen storage capacity (10.8 wt.％) and potentially safe operation. An experimental study has been performed on the catalytic reaction rate and pressure drop of a $NaBH_4$ solution over both a single microchannel with a hydraulic diameter of $300{\mu}m$ and a staggered array of micro pin fins in the microchannel with hydraulic diameter of $50{\mu}m$. The catalytic reaction rates and pressure drops were obtained under Reynolds numbers from 1 to 60 and solution concentrations from 5 to 20 wt.％. Moreover, reacting flows were visualized using a high-speed camera with a macro zoom lens. As a result, both the amount of hydrogenation and pressure drop are 2.45 times and 1.5 times larger in a pin fin microchannel array than in a single microchannel, respectively.

• The Journal of the Korea Contents Association
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• v.6 no.5
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• pp.170-177
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• 2006

The purpose of this study is to enhance efficiency of menu management of information system on the institutional restaurant according to the academic background, working career, and times of meal serving. The questionnaires were distributed to 120 units. A total of 116 questionnaires were usable. First, result that is significant to menu management factor at meals manager's work career and food information system operation analyzed that is. Second, analyzed that difference of meals subdivision meal number is not significant to menu management factor at food information system operation. Third, manager's attainments in scholarship which operate food information system analyzed that practical use degree is significant to menu management factor at food information system operation.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.4
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• pp.174-178
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• 2008

Nano-crystalline slaked lime was synthesized using design of experiment. In order to synthesize slaked lime, calcium chloride $(CaCl_2)$ and urea were used as starting materials. Calcium chloride solution and urea solution were mixed and heated in vessel that calcium carbonate was precipitated during heating. Precipitates were filtered, washed several times using D.I.water and ethanol and finally dried in oven. Slaked lime $(Ca(OH)_2)$ has been fabricated by the hydration of calcined $CaCO_3$. Design of experiment (Taguchi method) was used to optimize parameter, to minimize noise factors of experiment and to statistically analyze the results. Slaked lime having about 50 nm in optimized crystallite size could be obtained by calcination of $CaCO_3$ at $1000^{\circ}C$ for 0.5 h and hydration with D.I water containing ethanol and oxalic acid.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.2
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• pp.139-146
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• 2014

Sodium borohydride ($NaBH_4$) is considered as a secure metal hydride for hydrogen storage and supply. In this study, the interfacial friction of two-phase flow in the dehydrogenation of aqueous $NaBH_4$ solution in a microchannel with a hydraulic diameter of $461{\mu}m$ is investigated for designing a dehydrogenation chemical reactor flow passage. Because hydrogen gas is generated by the hydrolysis of $NaBH_4$ in the presence of a ruthenium catalyst, two different flow phases (aqueous $NaBH_4$ solution and hydrogen gas) exist in the channel. For experimental studies, a microchannel was fabricated on a silicon wafer substrate, and 100-nm ruthenium catalyst was deposited on three sides of the channel surface. A bubbly flow pattern was observed. The experimental results indicate that the two-phase multiplier increases linearly with the void fraction, which depends on the initial concentration, reaction rate, and flow residence time.