• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.240-243
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• 1995

This paper deals with the high efficiency drive of a vector controlled inverter fed induction motor system for electric vehicles. The loss equation is derived from the voltage equations in synchronously rotating reference frame. The ratio of the d-axis and q-axis component currents should be maintained constant to maximize the efficiency at a specified speed. Digital simulations are curried out and the results are compared with those of the conventional constant flux control.

• KDI Journal of Economic Policy
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• 제46권3호
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• pp.1-23
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• 2024

This study empirically investigates the impact of recent US export controls on China on South Korea's semiconductor exports. We analyze South Korean export data to shed light on the repercussions of US export restrictions on a third country. Our findings reveal a significant decline in Korean semiconductor exports following the October 2022 imposition of US controls. This decline was most pronounced in the memory, discrete devices, and discrete device components subsectors of the semiconductor industry. In addition, we observed a decrease in unit prices, especially for memory semiconductors, pointing to downward pressure on South Korea's high-value-added semiconductor exports. These results provide some evidence of substantial negative impacts of US export controls on South Korea's semiconductor industry, and particularly with regard to its high-tech products.

• 기술혁신연구
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• 제29권3호
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• pp.33-62
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• 2021

본 연구는 기술혁신형 중소기업의 연구개발 활동 효율성을 산업 간 비교하여 개선방안을 제시한다. 연구표본은 2008년부터 2011년까지 기술보증기금의 기술평가보증을 받은 6,708개 기업이다. 투입변수는 기술인력수준과 연구개발투자, 산출변수는 특허출원과 시제품제작실적이다. 효율성은 DEA 모형으로 측정하며, 산업별 개별측정하는 간접비교를 수행한다. 그 결과로 최적의 규모수익을 판단하는 기술효율성(CCR)은 0.19, 최적의 투입분배를 판단하는 순수기술효율성(BCC)은 0.70, 최적의 산출규모를 판단하는 규모효율성(SE)은 0.30으로 나타났다. 산업유형으로 살펴보면, 중·저급기술산업군은 규모효율성이 낮아서 연구성과 확대가 요구되고, 고급·첨단기술산업은 순수기술효율성이 낮아서 투입요소 관리가 필요하다. 산업 전반에 규모의 비효율이 크므로 연구성과 관리를 통한 규모의 확대가 이뤄져야 하며, 이를 위한 연구인력과 투자비의 분배가 병행되어야 효율성이 향상될 것이다. 본 연구는 우리나라 기술혁신형 중소기업에서 연구개발의 비효율성 원인이 규모에 있다는 것을 기술보증기금의 기술평가자료로 규명한 것이 특징이다.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2005년도 공동추계학술대회
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• pp.241-250
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• 2005

New product development (NPD) is defined as the transformation of a market opportunity and a set of assumptions about product technology into a product available for sale. Managers charged with project selection decisions in the NPD process, such as go/no-go choices and specific resource allocation decisions, are faced with a complicated problem. Therefore, the ability to develop new successful products has identifies as a major determinant in sustaining a firm's competitive advantage. The purpose of this study is to develop a new evaluation model for NPD project selection in the high -tech industry using support vector machines (SYM). The evaluation model is developed through two phases. In the first phase, binary (go/no-go) classification prediction model, i.e. SVM for high-tech NPD project selection is developed. In the second phase. using the predicted output value of SVM, feasibility grade is calculated for the final NPD project decision making. In this study, the feasibility grades are also divided as three level grades. We assume that the frequency of NPD project cases is symmetrically determined according to the feasibility grades and misclassification errors are partially minimized by the multiple grades. However, the horizon of grade level can be changed by firms' NPD strategy. Our proposed feasibility grade method is more reasonable in NPD decision problems by considering particularly risk factor of NPD in viewpoints of future NPD success probability. In our empirical study using Korean NPD cases, the SVM significantly outperformed ANN and logistic regression as benchmark models in hit ratio. And the feasibility grades generated from the predicted output value of SVM showed that they can offer a useful guideline for NPD project selection.

• Current Photovoltaic Research
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• 제6권2호
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• pp.49-55
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• 2018

Recently solar cell industry needs the optimal design of Czochralski process for low cost high quality silicon mono crystalline ingot. Because market needs both high efficient solar cell and similar cost with multi-crystalline Si ingot. For cost reduction in Czochralski process, first of all energy reduction should be completed because Czochralski process is high energy consumption process. For this purpose we studied optimal water-cooling tube design and simultaneously we also check the quality of ingot with Von mises stress and V(pull speed of ingot)/G(temperature gradient to the crystallization) values. At this research we used $CG-Sim^{(R)}$ S/W package and finally we got improved water-cooling tube design than normally used process in present industry. The optimal water-cooling tube length should be 200mm. The result will be adopted at real industry.

• 한국생산제조학회지
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• 제19권3호
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• pp.346-352
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• 2010

Recently, the high-tech industries, such as the aerospace industry, the auto industry, and the electronics industry, are growing up considerably. Because of that, high machining accuracy and productivity of precision parts have been required. The tooling system is important part in the machining center. HSK tooling system is more suitable than BT tooling system for that of high speed machining center. It is because static stiffness and machining accuracy of HSK tooling system are higher than those of BT tooling system. In this paper, static and dynamic behavior of the HSK tooling System is analyzed according to bearing characteristics and lightweight parts. In order that, three different models of the HSK tooling system are modelled by using a 3D modeling/design program. More stable one in the models of HSK tooling system can be selected by using the FEA(Finite Element Analysis).

• 한국전산유체공학회지
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• 제18권3호
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• pp.67-71
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• 2013

Recently, the rapid development of the semiconductor industry induces the prompt technical progress in the area of device integration and the application of large diameter wafers for the price competitiveness. As a result of the usage of large wafers in the semiconductor industry, the silicon carbide components which have layers of silicon carbide on graphite or RBSC substrates is getting widely used due to the advantages of SiC such as high hardness and strength, chemical and ionic resistant to all the environments superior than other ceramic materials. For the uniform and homogeneous deposition of silicon carbide on these huge components, it needs to know about the gas flow in the CVD reactor, not only for the delicate adjustment of the process variables but more essentially for the cost reduction for the shape change of specimens and their holders on the stage of reactor. In this research, the CFD simulation is challenged for the prediction of the inner distribution of the gas velocity. Chemical reaction simulation is used to predict the distribution of concentration of the reacting gas with the rotating velocity of the stage. With the increase of the rotating speed, more uniform distribution of the reacting gas on the surface of the stage was obtained.

• The Journal of Asian Finance, Economics and Business
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• 제8권5호
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• pp.749-759
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• 2021

We investigate the relationship between ownership control disparity and future firm value in high-technology industries, and whether the effect of ownership control disparity on future firm value is differentiated when high-tech industry firms belong to chaebol groups. Using 11,848 firm-year observations of Korean firms listed on the stock market from 2006 to 2019, we employ univariate analysis and Heckman 2 stage analysis to test our hypotheses. We define high-technology industries as ICT industries based on the Korean Standard Industrial Classification. We measure future firm value using average Tobin's q for the next three years and ownership control disparity using the shareholding ratio of affiliated companies. Our univariate test results show that mean of Tobin's q is higher in ICT firms than non-ICT firms and firms largely owned by affiliates. In multivariate test, we find that the ICT firms with higher ownership control disparity are positively associated with future firm value. However, this association is lessened when firms belong to a chaebol group. Based on our findings, we suggest ownership control disparity has an additional positive effect on future firm in high-technology industries. The negative impact of chaebol groups on the association suggests the possibility of diversification discount in business group.

• Asian Journal of Innovation and Policy
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• 제1권1호
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• pp.116-132
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• 2012

This paper deals with university - industry collaboration movement in China in recent years. By summarizing related development background in Government-Industry-University framework, the paper specifies Chinese pattern through analysis of technology transfer between universities and industries, collaborative R&D between universities and industries in practical fields, and university-run high-tech companies, especially through analysis of joint patenting between universities and their industrial partners in China. The research provides clear picture of Chinese universities' increased development with industrial entities in comprehensive and wider technology fields.

• 식품과학과 산업
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• 제50권3호
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• pp.2-32
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• 2017

Due to the increasing demand for convenience and simplicity, Home Meal Replacement (HMR) has become a key trend in the food service industry. This study researched the current consumer trend and analyzed the national and international HMR product trend, aiming to find useful insights for the field. Results showed that in order to expand the HMR market demand, it is possible to consider diversifying the product category by making customized premium products, such as products for the elderly, infants, patients, and sports players, or products with enhanced nutritional fortification. From the industrial aspect, centralization through Central Kitchen (CK) and implementation of the scientific and advanced ISO and HACCP system are necessary. Lastly, to develop high value-added HMR products, it is deemed essential to utilize the so-called 'food tech', the technology which integrates core technologies of the fourth industrial revolution into the food industry.