• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 F
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• pp.2088-2090
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• 1998

A low-cost electronic starter is developed to decrease ignition failure significantly through successive starting trial and to prevent overheating at the end of fluorescent lamp life. Moreover, it has an additional feature of being capable of ignition at the recovered lamp voltage without any circuit correction. The developed electronic starter is consisted of four parts - a half wave rectifier circuit, a timer circuit, a switching circuit and a protection circuit. The protection circuit made up of a transistor and capacitors utilizing capacitive characteristics, carries out successive starting trial and end-of-life protection. Lamp ignition is completed within 0.5 seconds with taking advantage of a high preheating current from the half-wave rectifier circuit. Nevertheless, its performance is proved to be very excellent through a standard switching endurance test.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 E
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• pp.1620-1622
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• 1998

The failure occurs in the system of the underground transmission line, the time of restoration is very long, the damage from stopping power supply is very serious and the cost of restoration is very great. because of these problems, the system and equipment must be protected from every electrical failure by installing protection unit. This study is summarized and compared the effects of configuration method of cable protection device with respect to surges in EHV (Extra High Voltage) underground transmission system.

• 전기학회논문지
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• 제67권8호
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• pp.1113-1118
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• 2018

Protection in HVDC(High Voltage Direct Current) have the very fast velocity of fault detection. Because Fault in HVDC has the fast propagation, large currents, high interruption cost. The focus to velocity caused possibility of errors like a detection error like a high impedance fault. In this paper, Proposed complex composition for get the reliability and velocity. That used SFCL(Super Conducting Fault Current Limiter), Protection Zone and DTS(Distributed Temperature Sensing). The SFCL was detect the fault by quench and DTS&Protection Zone were perceive the detect by variation too. To examine the proposed method, PSCAD/EMTDC simulated. The results of simulation, proposed methods could the detect of fault to whole HVDC line. And that improved the reliability of fault clearing.

• 한국안전학회지
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• 제25권6호
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• pp.155-160
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• 2010

In this study, detailed assessment for durability performance were performed on the chloride protected concrete structures to investigate the effectiveness of chloride protection. And economical efficiency for the chloride protected concrete structures were studied by LCC(Life Cycle Cost) analysis. In the comparison result of the first section repair time, it was found that the chloride protected concrete structures was economical better than the non-protected concrete structures in the long term. According to the analysis result of the accumulated chloride concentration by used time and chloride ion concentration by depth, it can be seen that the permeation through time from chloride has increased two times in the chloride protected concrete structures.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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• pp.213-218
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• 2001

These days, corrosion condition of a underground objects is measured by the electric potential between the subject and ground. But this method is implemented by means of manual work with analog voltmeter, which is uneconomic and inefficient. So, We developed real-time On-Line cathodic protection monitoring system that is able to detect corrosion potential conditions of metal objects or various steel structures in the ground continuously, display them with the graphic screen, construct a database, and analyze them simultaneously. Since the data of corrosion and corrosion protection of all underground objects is processed automatically, not manually in this system, It is possible to reduce the manipulated error, and perform precise safety management, maintenance and inspection. As as result, this system can not only guarantee long-life operation, reduction of manpower and cost, but prevent large accidents in advance.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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• pp.219-226
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• 1997

This paper investigates and analyzes the installation and failure status of mold transformer being used in domestic subways and describes the extinguishing process by time through the combustion test of winding part of mold transformer. Condition of installed mold transformers and classes of fire were surveyed and the mold transformer was burned in a horizontal heating furnace. It was confirmed that the mold transformer is self extinguishing and nonflammability. According to this results, the suitable standard of fire protection for the mold transformer was demanded after review of domestic and abroad law. It is expected that the cost of fire protection equipment can be reduced by using the status and combustion test result of mold transformer.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권12호
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• pp.6123-6138
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• 2018

Named data networking (NDN) is a new network architecture designed for next generation Internet. Router-side content caching is one of the key features in NDN, which can reduce redundant transmission, accelerate content distribution and alleviate congestion. However, several security problems are introduced as well. One important security risk is cache privacy leakage. By measuring the content retrieve time, adversary can infer its neighbor users' hobby for privacy content. Focusing on this problem, we propose a cache privacy protection mechanism (named as CPPM-DAM) to identify legitimate user and adversary using Bloom filter. An optimization for storage cost is further provided to make this mechanism more practical. The simulation results of ndnSIM show that CPPM-DAM can effectively protect cache privacy.

• Journal of Korea Trade
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• 제23권4호
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• pp.115-130
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• 2019

Purpose - This paper examines the impact of labor market regulations on FDI and the production of foreign firms. Design/methodology - We use an index of employment protection along with data on the FDI and production of foreign affiliates that are provided by the OECD. Findings - The empirical results show that strict employment protection discourages both the production and initial entry of foreign firms, with its impact on production being larger than that on the initial entry decision. The result is robust to various specifications in which instrumental variable estimations are used by applying a unionization rate and a severance pay for redundancy dismissal as instruments, respectively. Therefore, policymakers should not limit their focus to tax incentives, cash grants, and relaxation of market regulations, but they should also extend their attention to labor market deregulation and decreasing non-wage cost to attract more foreign firms into their countries. Originality/value - This paper attempts to answer the question on the impact of employment protection rules on the foreign firm's decisions regarding production as well as initial entry.

• Asia Pacific Journal of Business Review
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• 제4권1호
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• pp.1-34
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• 2019

This study investigates whether and how a firm's cost of equity capital is influenced by the extent of a firm's real earnings management (REM). Using a large sample of Hong Kong and Chinese firms over the 9-year period 2009-2017, we find that our implied cost of equity estimates are positively associated with both the extent of REM and the extent of accrual-based earnings management (AEM), but the positive association is stronger for REM than for AEM. We also provide evidence suggesting that the effect of AEM and REM on the cost of equity is more pronounced for Hong Kong firms than Chinese firms, and within Chinese firms, it is less pronounced for the state-owned enterprises (SOEs). Collectively, our results suggest that while both REM and AEM exacerbate the quality of earnings used by outside investors, REM does so to a greater extent than AEM, and thus the market demands a higher risk premium for REM activities than for AEM activities and that this cost of capital-increase effect is more prominent in a developed market like Hong Kong and mitigated by state ownership in China because of investors' expectations for a lower level of detriments to firm fundamentals by REM due to government's protection in a less developed market like China.

• Journal of Forest and Environmental Science
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• 제23권1호
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• pp.21-28
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• 2007

본 연구는 환경친화적 녹색임도 구현을 위해 1990년부터 2003년까지 시공된 충청남도 민유임도의 임도설계서를 검토하여 적용공종의 변화를 분석하고 평가하였다. 임도사업비의 변화추이는 사업연도에 따라 꾸준히 증가되었고 특히 환경친화적 녹색임도 구현을 위한 임도정책이 수립된 1999년과 2000년도에 사업비가 대폭 증가한 것으로 나타나 비교적 견실한 임도시공이 이루어질 수 있는 기반이 조성된 것으로 판단된다. 또한 토공사업의 비욜은 1999년 약 25.4%에서 2000년부터 2003년까지 토공사업비 평균비율이 18.5%로 감소된 것으로 나타났다. 하지만 토공의 비율이 줄어든 것과는 달리 비탈면보호공이나 구조물공의 총액은 상승하였으나 비율은 거의 증가하지 않은 것으로 나타났다. 이는 적용 구조물의 규격확대와 적용 물량의 증가에 따른 자재대의 비율과 제경비의 상승에 기인한 것으로 구조물공과 비탈면보호공에 소요되는 재료가 증가한 것으로 판단할 수 있다. 향후 공사비의 증가가 적용 구조물의 규격확대와 투입량 증가만으로 이어질 경우 임도시공 노하우와 경쟁력 약화를 초래할 수 있으므로 보다 다양한 공법의 적용과 개발노력이 요구된다.