• 전기학회논문지
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• 제59권11호
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• pp.1996-2005
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• 2010

This paper proposes a new method for constant control of the output AC voltage of a voltage-fed three phase Z-source inverter (ZSI), in case of Z-network DC voltage variation or heavy change of load. The modulation index for the reference output AC voltage of ZSI can be calculated by the basic definition of ZSI, the input DC voltage and capacitor voltage of Z-network. And, the output AC voltage of ZSI is controlled by the modified space vector modulation (SVM) with the calculated modulation index. By the proposed method, the modulation index of output AC voltage is closely following in the reference modulation index. The validity of the proposed method is verified using PSIM simulation. In case which the input DC voltage of ZSI is heavily changed from 100[V] to 70[V] (or to 150[V]) and in case which load is changed from $30[\Omega]$ to $10[\Omega]$, we confirmed that the output AC voltage of ZSI is constantly controlled by the proposed method because the modulation index of ZSI is also simultaneously changed. Finally, FFT and %THD of the output voltage and current of ZSI by the proposed method are analyzed.

• 수산해양교육연구
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• 제29권2호
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• pp.560-569
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• 2017

With a remarkable and rapid change of universities in Korea, the role of universities has been changed from a traditional education supplier to a demander. Both the remarkable decrease of the number of entering students and the advent of an open education market are enforcing the universities to be changed. Universities should provide a variety of educational services in accordance with the students' needs. This study is based on the systematical Kuh's model which the educational service quality provide a decision making of alternative plan. This research is purposed to empirically study the effects of educational service quality(circumstance index, input index, participate index, output index) provided by universities on student satisfaction and educational performance(Perceived usefulness, Education Achievement). The results of this research follows; first, circumstance index, input index and output index significantly effect student satisfaction, but participate index does not effect satisfaction. Second, student satisfaction significantly effects on the educational performance.

• 전기학회논문지
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• 제60권8호
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• pp.1515-1522
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• 2011

This paper proposes the algorithm for the output AC voltage control of Z-source inverter by the detection of the input DC voltage and Z-network capacitor voltage. The actual modulation index of the proposed method is detected by the capacitor voltage in Z-network and input DC voltage of three-phase Z-source inverter. Control modulation index for the output voltage control is calculated by the detected actual modulation index and reference modulation index. And, calculated control modulation index is applied to the modified space vector modulation (SVM) for control the output voltage of Z-source inverter. To verify the validity of the proposed method, PSIM simulation was achieved and a DSP controlled 1[kW] three-phase Z-source inverter was producted. The simulation and experiment were performed under the condition that the load was changed in case of the constant input DC voltage and the input DC voltage was changed in case of the load was constant. As a result, we could know that the output phase voltage of Z-source inverter followed to the reference voltage 70[VRMS] despite the load or the input DC voltage were suddenly changed.

• Journal of Information Technology Applications and Management
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• 제21권4_spc호
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• pp.381-401
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• 2014

This study proposes the accurate economic effect (employment inducement coefficient, hiring inducement coefficient, index of the sensitivity of dispersion, index of the power of dispersion, and ratio of value added) of Korea software industry by analyzing the inter-industry relation using the modified inter-industry table. Some previous studies related to the inter-industry analysis were reviewed and the key problems were identified. First, in the current inter-industry table publishedby the Bank of Korea, the output of software industry includes not only the output of pure software industry (package software and IT services) but also the output of non-software industry due to the misclassification of the industry. This causes the output to become bigger than the actual output of the software industry. Second, during rewriting the inter-industry table, the output is changing. The inter-industry table is the table in the form of rows and columns, which records the transactions of goods and services among industries which are required to continue the activities of each industry. Accordingly, if only an output of a specific industry is changed, the reliability of the table would be degraded because the table is prepared based on the relations with other industries. This possibly causes the economic effect coefficient to degrade reliability, over or under estimated. This study tries to correct these problems to get the more accurate economic effect of the software industry. First, to get the output of the pure software section only, the data from the Korea Electronics Association(KEA) was used in the inter-industry table. Second, to prevent the difference in the outputs during rewriting the inter-industry table, the difference between the output in the current inter-industry table and the output from KEA data was identified and then it was defined as the non-software section output for the analysis. The following results were obtained: The pure software section's economic effect coefficient was lower than the coefficient of non-software section. It comes from differenceof data to Bank of Korea and KEA. This study hasa signification from accurate economic effect of Korea software industry.

• 통상정보연구
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• 제9권2호
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• pp.423-439
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• 2007

The purpose of this study was to analyze market competitiveness of Korean and Chinese computer parts industry in the between two countries' market by using Index of Export Bias and Market Comparative Advantage Index. For attaining the purpose of study, we classified the computer parts which exported to the two countries' market and the imported products as the memory devices and input/output peripheral devices. Analyzing period was 2001-2006. The analysis of Korean results of Index of Export Bias indicated that memory devices represented low overall numerical value and the Chinese results of Index of Export Bias indicated that memory devices represented high gradual numerical value. On the other hand, Korean input/output peripheral devices have been increasing steadily for analysis period and China input/output peripheral devices have been decreasing steadily for analysis period. Additional results indicated that the Korean and China computer parts which gained market competitiveness between two countries market were as follows. Korean memory devices have been losing competitiveness in the China market steadily and Chinese memory devices have been acquire competitiveness in the Korean market gradually. In input/output peripheral devices case, Korean products represented powerful competitiveness in the China market and Chinese products have been gaining competitiveness in the Korea market.

• STI Policy Review
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• 제1권2호
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• pp.51-68
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• 2010

This paper compares OECD nations by developing a comprehensive evaluation index that examines the efforts and achievements of countries toward Low-Carbon Green Growth. The input-process-output of a Low-Carbon Society system is in dynamic competition with that of a High-Carbon Society system. The model used in this study of the comprehensive evaluation index for Low-Carbon Green Growth was comprised of Large indices such as Input, Process, and Output. The Input and Output consisted of 'Social-economic' and 'Physical-ecological' Middle indices while the Process was made up of 'Stimulation mechanisms' and 'Participation of stakeholders and Knowledge flow' Middle indices. In order to calculate the comprehensive evaluation index, our model gave a weight to each indicator/index and applied a weighted arithmetic mean. Korea ranked $15^{th}$ out of 30 OECD nations in the comprehensive evaluation that analyzed Input ($14^{th}$), Process ($18^{th}$), and Output ($17^{th}$). The top five nations were Switzerland, Sweden, Denmark, Germany, and France; while Japan was $8^{th}$ and the USA $26^{th}$.

• 대한전자공학회논문지
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• 제17권6호
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• pp.38-43
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• 1980

시간에 따라 변하지 않는 선형 다변수 시스템의 출력 궤환 제어를 이산시간계에서 최적화 하기 위한 필요 조건을 유도했다. Quadratic performance index를 사용했다. 결과는 출력의 비례적분 궤환의 최적이득을 구하는 데에도 쉽게 적용할 수 있다. 예제를 들어 최적 궤환이 득을 구했다.

• 기술혁신연구
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• 제19권1호
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• pp.1-27
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• 2011

본 연구는 1984년부터 패널자료의 확보가 가능한 17개 OECD 국가를 표본으로 하여 R&D 생산성 및 효율성에 대한 실증분석을 통해 비교하고 우리나라의 수준과 특징을 살펴보고자 하였다. 이를 위해 그 성과를 산출(output) 측면과 성과(outcome) 측면으로 구분하고, 맘퀴스트 생산성지수와 자료포락분석방법을 활용하여 R&D경로단계별 생산성 및 효율성과 그 변화추이를 비교분석하였다. 우리나라는 R&D 투자 대비 산출 생산성은 매우 높은 반면, 평균효율성은 매우 낮게 나타났으며, 효율성의 시계열 변화추이를 보면 최초 지수 0.10에서 시작하여 최종 0.83까지 가파르게 상승하면서 주요 선진국들 수준에 도달하였다. R&D 산출 대비 생산성은 매우 낮으며, 통합 프런티어에 대한 효율성은 최초 지수 1.00에서 최종 0.057까지 주요 선진국들 수준으로 가파르게 하락하여 왔다. 그리고 상관분석을 통해 R&D 산출 대비 생산성이 곧 R&D 투자 대비 생산성을 가늠하는 지표가 될 수 있음을 보았다. 본 연구는 우리나라의 R&D 생산성 및 효율성 향상을 위해서는 R&D 투자 및 산출 증대의 노력이상으로 R&D 산출물의 활용 측면이 보다 강화되어야 하고 이를 위해 효과적인 기술확산 체계 구축, 기술금융시장환경 조성 및 사업화에 성공하기까지 실질적인 인큐베이팅 제공 등 전반적인 기술사업화 시스템의 혁신이 주요 과제임을 시사하고 있다.

• 산업경영시스템학회지
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• 제30권3호
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• pp.82-88
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• 2007

Service engineering is a new discipline which aims at basically understanding of service and a concrete methodology using engineering approach for service design. In this paper is introduced the serviset graph [7] which is a comprehensive concept to represent service products, processes, and operation activities. The proposed concept is a degree of commonality index in a service product in order to deal with service mass customization using the input-output analysis in economic model.

• International journal of advanced smart convergence
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• 제11권2호
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• pp.171-184
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• 2022

The purpose of this paper is output oriented, in order to maximize the output level of sustainable development efficiency of foreign trade in western China with limited input. This paper adopts the relevant input-output indicators of sustainable foreign trade development of 11 provinces and cities in western China from 2016 to 2020, and uses DEA model to measure their technical efficiency, pure technical efficiency and scale efficiency. Malmquist index was used to calculate the total factor productivity change index of each province in western China from 2016 to 2020. We found that, on the whole, the average values of technical efficiency, pure technical efficiency and scale efficiency of provinces and cities in western China from 2016 to 2020 are greater than 0.8, indicating that the western region has high technical efficiency, relatively high management and institutional level and high existing scale level. Scale efficiency is lower than pure technical efficiency on the whole, indicating that the current sustainable development efficiency of foreign trade in western China is mainly limited by its scale level. The technological progress index is higher than the technological efficiency change index, indicating that the total factor productivity of the sustainable development of foreign trade in western China is mainly driven by technological progress and more influenced by external factors. We think the conclusion of this study can provide important reference information for the sustainable development of foreign trade of provinces and cities in western China.