• Magazine of the Korea Concrete Institute
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• v.11 no.2
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• pp.221-230
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• 1999

Corrosion of rebars can occur if there are cracks, moisture and availability of oxygen or carbonation proceeds, chloride penetrates and diffuses in concrete. Once rebars in concrete corrodes, subsequently accompanied with scaling, spalling in concrete cover. As a result of them, the RC structure is seriously deteriorated. In this study, theoretical review and experiments for cathodic protection(CP) have been performed to control corrosion of rebars in concrete contained chlorides and pre-crack. For CP the impressed current system was applied, the protection effect was investigated when rebars was directly contacted with salt water due to crack and open to much chlorides in concrete. In order to investigate the effect of protection, when CP was energized for 1 year, half-cell potential, potential-decay with current density, corrosion ratio, etc. were measured. With the cathodic protection by impressed current system, the depolarized values of all specimen were met NACE Standard, the effect of 34~84% of the ratio of corrosion area and 84~86% of cross-section reduction were calculated.

• Convergence Security Journal
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• v.19 no.4
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• pp.3-12
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• 2019

The outflow of defense technology can cause serious damage not only in terms of business losses, but also in terms of national security and national interests. Recently, the government has enacted the Defense Technology Security Act, recognizing the importance of technology in the defense industry, and prepared guidelines for the defense technology security accordingly. According to the law, institutions and companies with defense technologies should establish a defense technology protection system, and the government should implement various technology protection policies to improve their level of technology protection. In this study, the implications were derived by comparing existing technology protection guidelines and priority analysis was performed on the protection system details through AHP for self-diagnosis items in the defense technology security guidelines. As a result, it is expected that it will enable efficient diagnosis of the level of protection and policy support for the systematic establishment of the protection system for the target institutions.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.2
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• pp.163-168
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• 2010

This paper presents the practical implementation of an over-temperature protection system for power semiconductor devices. In the proposed system, temperature variation is provided with just using $R_{ds(on)}$ characteristics of power MOSFET, while extra device such as a temperature sensor or an over-temperature detection transistor is needed to monitor the temperature in the conventional method. The proposed protection technique is experimentally tested on IRF840 power MOSFET. The PIC microcontroller PIC16F877A is used for the implementation of the proposed protection algorithm. The built-in 10-bit A/D converter is utilized for detecting voltage variance between a drain and a source of IRF840. The induced temperature-resistance relationship based on the measured drain-source voltage, supplies a gate signal to the power MOSFET. If detected temperature's voltage exceeds any a protection temperature's voltage, the microcontroller removes the trigger signal from the power MOSFET. These test results showed satisfactory performances of the proposed protection system in term of accuracy within 1.5%.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.2
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• pp.15-20
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• 2023

Recently, digitalization is accelerating in all industries, and the use of information and personal information produced and used in the process of it is very important for the success or failure of a company. However, malicious attempts to steal or leak major information and personal information of a company as an adverse effect continue to increase, and appropriate defense and response are absolutely necessary. However, in the case of small and medium-sized enterprises, the priority of information protection and the possession of professional manpower are very insufficient compared to large enterprises. This paper studies the certification and audit implemented in Korea, and suggests ways to expand the certification of the information protection system suitable for SMEs and improve the effectiveness of the support system through the expansion of the privacy law notification standard and operation of support system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.1
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• pp.112-118
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• 2018

The purpose of this study is to analyze endangered species laws and systems in China from the viewpoint of the importance of protecting biodiversity and to propose suggestions for existing wildlife protection laws in China to improve efficacy. Since the People's Republic of China Wildlife Protection Act was promulgated and enforced in 1988, China has found that urgent amendments are necessary because of neglected management of the act. The content of the Wildlife Protection Act of China is not only monotonous and unsystematic, but also needs modification and supplementation because it is pre-modern and does not meet current demands. In comparison with other countries, the purpose of China's legislation, supervision system, scope of protection and public participation system differ. China's Wildlife Protection Act is also hindered by confusion in the legislative protection system, lack of an administrative compensation system, difficulties in implementation, deterioration of legal efficiency, lack of content and operations, and lack of a list of species that should be is protected. This paper proposes measures for improvement to solve this confusion in the legislative system for the endangered species protection law to establish a legal system suitable for the current situation in China.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.736-740
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• 2004

In order to overcome the problems of simulation methods, the power system transient stability assessment method using critical fault clearing time functions has been developed. Using the above method, this paper has developed the new method which can assess accurately and efficiently the effects of control and protection systems on transient stability which is the most important characteristic to assess in power systems. At first, critical fault clearing time functions CCT(W:load) are defined by taking notice of the fact that transient stability is mainly controlled by fault clearing time and load. Next, the method to be enable to assess accurately and efficiently the effects of control and protection systems on transient stability has been newly developed by using the above functions. Finally, it has been applied to the effect assessment in the occurrence of a three-phase fault in a model power system. Results of application have been clarified its effectiveness.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.7
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• pp.925-930
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• 2013

The fault current of the power transmission system is greater than that of the power distribution system. Therefore, the introduction of superconducting fault current limiter (SFCL) is more needed to reduce the increased fault current. The trigger-type SFCL consists of the high-temperature superconducting element (HTSC), the current limiting reactor (CLR) and the circuit breaker (CB). The trigger-type SFCL can be used to supplement the disadvantages of the resistive-type SFCL. The operation characteristics of the current ratio differential relay which is usually applied to the protection device of the power transmission system are expected to be affected under fault conditions and the applicability of the trigger-type SFCL. In this paper, we analyzed the operating characteristics, by the fault conditions, between the current ratio differential relay for line protection and the trigger-type SFCL in the power transmission system through the PSCAD/EMTDC simulation.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.3
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• pp.253-258
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• 2015

The 3D printing is any of various processes for making a three dimensional object of almost any shape from a 3D model. Recently, a rapidly expanding hobbyist and home-use market has become established with the inauguration of the open-source RepRap and Fab@Home projects. However, this causes problems regarding copyright protection and usage of illegal 3D data. In this paper, we developed a 3D printing open-market system, which guarantees copyright protection using the remote 3D printing without direct distribution of 3D design data. Because most of the home-use 3D printers are FFF (Fused Filament Fabrication) based on NC code system, open-market system uses FFF 3D printers. Also, open-market system inspects the uploaded 3D model data, so the system can prevent distribution of illegal model data such as weapons, etc.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.4
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• pp.1548-1568
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• 2015

Korea's Compulsive Shutdown System bans online game providers from offering their services to children under 16 years of age from midnight to 6 a.m. Although it was introduced only after lengthy rounds of discussion, controversy over the system still continues. The key question is whether the system, which unilaterally emphasizes juvenile protection, infringes upon the freedom of playing games for teenagers, the freedom of business for game products related business operators and the right to foster children for parents, which are basic rights under the Constitution. It is very encouraging that the State took up the issue and prepared various systems for juvenile protection through the Compulsive Shutdown System. Yet the government has to plan as comprehensive and effective of a measure as it possibly can by predicting the trends of technology development and game use, and also set detailed standards to ensure that the system should not become an excessive or inappropriate regulation. Although the State's compulsive intervention may be positive since it is hard to expect a self purification capability to exhibit itself concerning game use among teenagers, a plan to prevent game addiction among adolescents from the long-term and fundamental perspectives should be prepared as well.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.9
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• pp.880-887
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• 2004

In this paper we analyze the satellite DMB system E using CDM/QPSK transmission system in 2,630～2,655 MHz(25 MHz) bandwidth by computer simulation. Based on this result, we propose the protection ratio analysis and values to guarantee the Performance of the satellite DMB system E from the interference of CATV using the same spectrum. As a result, we confirmed that the protection ratio between DMB and wireless CATV should be guaranteed -16.3 dB in AWGN channel and -11.3 dB in Rician Fading(Channel model A) channel. These research results can be important fundamental material for the commercialization of satellite DMB system.