• Journal of Advanced Navigation Technology
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• v.23 no.2
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• pp.166-171
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• 2019

This paper has designed a current mode class D power amplifier to increase the transmission efficiency of a 6.78 MHz wireless power transfer (WPT) transmitter and to ensure stable characteristics even when the transmitting and receiving coil intervals change. By reducing the loss due to the parasitic capacitor component of the transistor, which limits the theoretical efficiency of the linear amplifier, this research has improved the efficiency of the power amplifier. The circuit design simulator was used to design the high efficiency amplifier, and the power output and efficiency characteristics according to the load impedance change have been simulated and verified. In the simulation, 42.1 dBm output and 95% efficiency was designed at DC bias 30 V. The power amplifier was fabricated and showed 91% efficiency at the output of 42.1 dBm (16 W). The transmitting and receiving coils were fabricated for wireless power transfer of the drone, and the maximum power added efficiency was 88% and the output power was $42.1dBm{\pm}1.7dB$ according to the load change causing from the coil intervals.

• Journal of Technology Innovation
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• v.19 no.1
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• pp.1-27
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• 2011

This paper aims to measure and analyze R&D productivities and efficiencies of 17 major OECD countries including Korea over the 1984-2008 period by using the Malmquist Productivity Index and Data Envelopment Analysis, classifying R&D performance into an output and outcome aspects. It also searches the Korea's current status and characteristics in each R&D stage to enhance Total Factor Productivity (TFP) compared with other developed countries. Our major findings are the followings: (i) Korea's productivity index of R&D input vis-a-vis R&D output is very high (13.39% annual growth rate) compared with those of major advanced countries, whereas the annual average of efficiency index is very low (0.33), i.e. Korea's technical efficiency index has risen to 0.83 at the last time series started at 0.10 point and come up to the level of major advanced countries. (ii) the Korea's productivity index of R&D output vis-a-vis R&D outcome is very low (14.02% annual reduction rate) compared with those of major advanced countries, whereas the annual average of efficiency index is very high (0.22), i.e. Korea's integrated frontier technical efficiency index has dropped to 0.057 at the last time series started at 1.00 point and coming up to the level of major advanced countries. (iii) The productivity of R&D input vis-a-vis R&D outcome is positively correlated with that of R&D output vis-a-vis R&D outcome and the growth of R&D input factors. In a nutshell, it implicates that the effort to take advantage of R&D outputs, namely establishing the diffusion and commercialization system of technical knowledge to the level of developed countries, should be strengthened over that on the growth of R&D investment and output for enhancing R&D productivity and efficiency in Korea.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.7
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• pp.571-579
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• 2013

This paper proposes an energy-efficient mode selection and power allocation scheme in device-to-device (D2D) communication system as an underlay coexistence with cellular networks. We analyze the energy efficiency which is defined as the summation of the energy efficiencies for all devices. The proposed scheme consists of two steps. First, we calculate the transmission power maximizing the energy efficiency for all possible modes of each device. Although the proposed power cannot maximize the system capacity, we prove that the proposed transmission power is the optimal power which maximizes the energy efficiency. In the second step, we select a mode which has the maximal energy efficiency among all possible mode combinations of the devices. Then we can jointly obtain the transmission power and the mode which can maximize the energy efficiency. The proposed scheme has the optimal performance with respect to the energy efficiency and outperforms the conventional schemes.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2011.06a
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• pp.345-362
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• 2011

국가 성장동력의 밑거름이 되는 R&D의 중요성이 높아짐에 따라 정부의 R&D 투자는 해마다 큰 폭으로 증가하고 있다. 정부 R&D 투자가 급증함에 따라 동시에 R&D의 효율성에 대한 문제가 제기되어 그 동안 R&D 효율성을 향상시키기 위한 많은 연구가 이루어졌다. 하지만 R&D 전주기 Plan-Do-See 관점에서 살펴보면 대부분의 연구가 기획(Plan)과 성과확산 및 사업화(See)의 문제해결을 통한 생산성 향상 전략 마련에 국한되어 온 것이 사실이다. 국가연구개발사업은 그 사업의 목표, 추진방법, 추진주체, 연구성과, 사업규모, 사업기간 등 다양한 특성에 따라 성공적인 사업운영을 위해 차별화된 관리 지원 시스템(Do)이 필요함에도 불구하고, R&D 효율성을 향상시키기 위한 R&D 지원시스템 관련 논의는 활발하게 이루어지지 않고 있다. 본 연구에서는 다양한 특성을 보유한 국가연구개발사업의 효율성을 향상시키기 위해 국가연구개발사업을 연구기간과 연구비에 따라 크게 4가지로 분류하여 각각의 R&D 특성을 고려한 R&D 지원시스템을 도출하고 그 발전방향을 제시하고자 한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.64-64
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• 2017

본 연구에서는 낙동강에 위치한 강정고령보에 설치된 자연형 어도의 유인효율 증대를 위한 어도의 위치 수정 제시를 하였다. 평면 2차원 물리서식처 모형인 River2D 모형을 통해 강정고령보의 자연형어도 입구부의 유속장과 WUA(Weighted Usable Area)를 이용하여 유인효율을 분석 실시하였다. 유인효율 분석 결과 자료와 2013년도 어류모니터링 자료를 통해 WUA는 어류 유인효율 평가하는 지수로 사용 될 수 있는 것을 간접적으로 검증하였다. 어류의 소상에는 유속이 중요한 인자로 작용한다. 모의를 통한 강정고령보의 유속장을 확인해보면 자연형어도가 설치된 좌안과는 반대로 우안쪽으로 형성되는 것을 확인하였다. 어도의 모양 및 위치를 수정한 지형자료를 이용하여 River2D 모형모의를 통한 어도의 유인효율을 증대 시킬 수 있는 방법을 제시하였다. 유속장이 주로 발생하는 보 우안쪽에 설치하는 것이 유인효율을 최대로 끌어낼 수 있었지만 비용적인 부분과 유인효율을 같이 생각한다면 현재 설치된 좌안 자연형어도의 입구부를 상류쪽으로 위치하여 재설치하는 것이 어류의 유인효율을 증대시켜주는 효과적인 제시방안이 되리라 사료 된다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.2
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• pp.287-292
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• 2015

In this paper, we evaluated the performance of D2D advertisement dissemination algorithms with maximum-distance and transmission-efficiency based relay selections with respect to the total number of successfully received users and transmission efficiency. To assume more practical environment, we took into account pre-defined target-areas based on the information of user density and the limit for the maximum number of relay users. Through the simulations we compared the performance results of both D2D advertisement dissemination algorithms with maximum-distance and transmission-efficiency based relay selections according to increment of the number of sectors. And then, we analysed the superiority of algorithm with transmission-efficiency based relay selections more than maximum-distance based relay selections.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2017.08a
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• pp.84-100
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• 2017

제1차 벤처붐을 겪은 이후 후기에 안정된 기업에 투자를 선호하는 벤처투자방식의 변화가 나타나고 있다. 기업성장단계에서 초기에서 중기에 있는 기업의 경우 자금의 부족을 경험하며, 지속적인 성장을 위해서 정부 R&D자금 지원을 받고 있다. 하지만 정부의 R&D자금 지원이 과연 지속가능성 측면에서 경쟁력이 있는 기업에게 지원되고 있는가에 대한 우려의 목소리가 있다. 본 연구는 제조업에 속하는 벤처기업을 대상으로 DEA 효율성 분석을 실시하였다. 이를 통하여 제조업에 속한 핵심 산업인 ICT제품과 같은 첨단제조와 기계, 자동차와 같은 일반제조에 속한 벤처기업의 효율성을 살펴보고, R&D지원을 받는 벤처기업과 그렇지 않은 기업을 비교분석한다. 추가로 두 집단 간의 특성(혁신성, 성장성, 수익성, 안전성)이 1년간 어떻게 변화하였는지 분석한다. 실증 분석결과, 제조업에 속한 R&D자금을 지원받는 벤처기업의 경우 그렇지 않은 기업보다 효율성이 낮은 것으로 나타났다. 이는 지원을 받은 벤처기업이 지속가능한 측면에서 비지원기업 보다는 경쟁력이 낮음을 시사한다. 그리고 1년간의 여러 특성의 변화를 살펴본 결과, 혁신성에서는 지원기업이 높은 성과를 창출하였지만, 수익성에 있어서 비지원기업 보다 저조한 것으로 나타났다. 따라서 정부의 R&D지원이 지속가능성 측면에서 경쟁력이 있는 기업에게 지원되기 위해서는 기술력뿐만 아니라 경영 효율성을 고려하는 시도가 필요하다.

• Journal of Korea Technology Innovation Society
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• v.12 no.1
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• pp.70-87
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• 2009

This paper studies the efficiency of public sector confronting with increasing oil price, economy crisis and energy-environment problems. In consideration that efficiency of national R&D program has been subjectively evaluated, this paper focuses objective validity by relative efficiency through a comparison among R&D programs in Korea. To implement this study, data published in national reports on R&D programs is used and analyzing method is induced by related books and theories. At the result of Data Envelopment Analysis on the collected data, this paper suggests the way to enhance the efficiency of nuclear R&D program. This study is the first on efficiency of national R&D programs applied DEA methods and is expected to contribute exploring the more efficient way of program management if more sophisticated DEA could be developed and applied.

• The Journal of Society for e-Business Studies
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• v.26 no.2
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• pp.45-59
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• 2021

As software(SW) has been considered as a key driver of the fourth industrial revolution, significant R&D investment has been made by Korean government. Despite the attention and support by the government, systematic analysis on the SW R&D efficiency has not been fully addressed. In this study, the efficiency of SW national research and development projects was analyzed using Data Envelopment Analysis(DEA) techniques. Efficiency was measured from both static and dynamic perspectives based on 1,463 projects conducted by the National IT Industry Promotion Agency(NIPA) from 2008 to 2018. The static efficiency analysis identified the causes of inefficiency as scale and technology problems. As a result of dynamic efficiency analysis, we present a sector-specific response model using an efficiency-stability matrix. This study is meaningful in that efficiency analysis was conducted on the entire SW national R&D project, and static/dynamic efficiency analysis results are expected to be used as a guideline for planning SW national R&D project.

• Journal of Technology Innovation
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• v.20 no.3
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• pp.29-55
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• 2012

In order to successfully adopt and implement the Balanced Scorecard(BSC), firms need to respond adequately to the rapid changes of today's business environment and consider the growing importance of non financial factors in the business activities such as intangible assets(R&D expenditure, patent, goodwill, etc.). Our primary focus throughout this paper is on developing Key Performance Index(KPI) of BSC for R&D expenditure activities. In this study, we have developed and named PEI(Patent Efficiency Index),which is the KPI for R&D expenditure by focusing on the efficiency of a patent that is the output from the R&D expenditures. Secondarily, we have attempted to address the solution for the current problems of the traditional R&D performance measurement by using our developed PEI and examine the usefulness and effectiveness of the newly developed our PEI. According to the empirical test results, we find that the PEI is positively associated with ROA and Tobin's Q, respectively and show that our developed PEI is more effective and accurate than the traditional R&D performance measurement as a business performance measurement. Furthermore, these findings proves that we can measure and evaluate how efficiently the firms perform the R&D activities and shows that the PEI can be a critical index for evaluating firm's business performance related to the R&D expenditures.