http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Client-Side Deduplication to Enhance Security and Reduce Communication Costs
김건우,윤택영,조남수,장구영 한국전자통신연구원 2017 ETRI Journal Vol.39 No.1
Message-locked encryption (MLE) is a widespread cryptographic primitive that enables the deduplication of encrypted data stored within the cloud. Practical clientside contributions of MLE, however, are vulnerable to a poison attack, and server-side MLE schemes require large bandwidth consumption. In this paper, we propose a new client-side secure deduplication method that prevents a poison attack, reduces the amount of traffic to be transmitted over a network, and requires fewer cryptographic operations to execute the protocol. The proposed primitive was analyzed in terms of security, communication costs, and computational requirements. We also compared our proposal with existing MLE schemes.
김건우,한정규,문건우 전력전자학회 2019 전력전자학회 논문지 Vol.24 No.6
Three-level (3L) DC–DC converters are appropriate for high-input-voltage applications. Although the voltage stress of TL converter switches can be reduced to half of the input voltage, the primary side has a large circulating current, which degrades efficiency. In this study, a dual half-bridge cascaded TL converter is presented to reduce this circulating current and thus decrease the conduction loss of the primary circuit. Moreover, the proposed converter can reduce the voltage stress of rectifier diodes, thereby reducing their conduction loss. Therefore, efficiency can be improved by reducing the conduction loss of the primary circuit and rectifier diodes.
김건우,서병철 한국재무학회 2010 한국재무학회 학술대회 Vol.2010 No.11
본 연구에서는 벤처기업 육성을 위해 중요한 기능을 수행하고 있는 벤처캐피탈의 자금투 자 유형별 성과차이를 분석하기 위해 2004~2005년 벤처캐피탈이 투자한 벤처기업 DB를 토대로 모수검정(t검정, 분산분석)과 비모수검정(Mann-Whitney Test, Kruskal Wallis Test), 다중회귀분석을 실시하여 벤처캐피탈의 자금투자여부, 투자규모, 자금조달방식, 투 자시점 및 투자방법에 따라 벤처기업의 성장성과 수익성에 미친 효과를 분석하였으며, 연 구결과는 다음과 같다. 먼저, 벤처캐피탈 투자여부에 따른 분석결과 벤처캐피탈 투자기업이 벤처캐피탈 비투자기 업 보다 매출액증가율과 자산증가율과 같은 성장성 지표에 있어 확연히 높은 성과를 나타 냈고, 자금투자 규모가 많을수록 성장성이 높은 것으로 나타났다. 이러한 결과는 벤처캐피 탈이 투자를 결정할 때 향후 성장성이 높을 것으로 기대되는 벤처기업에 투자를 한 것도 원인이 될 수 있지만, 벤처캐피탈의 자금투자가 벤처기업의 정보비대칭 문제를 완화시켜 벤처기업의 기업가치 제고에 긍정적인 영향을 미쳤기 때문으로 판단된다. 둘째, 자금조달 방식에서는 보통주 투자와 주식연계형채권 투자 간에 성장성과 수익성측 면에서 유의한 차이가 없는 것으로 나타났다. 이는 벤처캐피탈에게 상환권리가 있는 주식 연계형채권 투자의 경우 벤처기업의 대리인 문제를 완화시킴으로써 상대적으로 낮은 사고 율을 나타내는 것도 주요 요인일 것으로 판단된다. 셋째, 투자시점에 따른 성과 분석결과 성장성 지표에서 초기투자기업이 후기투자기업보다 높은 기업성과를 나타냈고 수익성 지표 중 총자산이익률에서 초기투자기업이 보다 높은 기 업 성과를 나타냈다. 이러한 결과는 Gompers(1995)의 연구결과 및 재무이론에서 밝히고 있는 위험과 수익률의 상반관계와 일치한다. 넷째, 투자방법에 따른 분석결과 공동투자가 기업의 성장성과 수익성에 긍정적인 영향을 미치지 않는 것으로 나타났다. This study has conducted to analyze the effect of fund investment, scope of investment, fund procurement method, investment time, and investment on the growth and profitability by implementing the parametric test (t-test and ANOVA analysis) and the parametric test (Mann-Whitney Test, Kruskal Wallis Test) as well as the multi-regression analysis on the basis of the venture company DB that venture capital invested during 2004~2005 in order to analyze the difference of outcome for each time of fund investment of venture capital that undertakes important functions for the development of venture companies and the followings are the result of such study. First of all, as a result of analysis following the investment of venture capital, the companies that received the venture capital investment showed higher growth than the company without the venture capital investment that displayed clearly better outcome with respect to the growth-ability indices, such as, the rate of increase in sales revenue and the rate of asset increase, and the more the scale of fund investment, the higher the growth. These results may be attributed to the investment to a venture company that is expected to have high probability of growth when the venture capital determines for investment, but it is more likely to have the positive influence of fund investment of venture capital moderates the information asymmetric problem of the venture company to improve the corporate value of the venture company. Second, the study found no noticeable difference in growth and profitability between the investments in common stocks and investment on equity-linked note (ELN) with respect to the fund procurement method. This is considered as a main cause of moderating the agency issue of venture company to display relatively lower incident rate for the case of the ELN investment that has the redemption right of the venture company. Third, as for the analysis of outcome following the investment time, the companies with initial investment displayed higher corporate outcome than the late investment companies with respect to the growth-ability index, and the initial investment company displayed better corporate outcome with respect to the gross asset profit rate from the growth-ability index. This type of result is consistent to the interrelationship of risk and yield as shown in the study result of Gompers (1995) and finance Theories. And, fourth, as a result of the analysis following the investment method, it showed that the joint investment did not have positive influence on the corporate growth and profitability.