• International Journal of Precision Engineering and Manufacturing
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• v.5 no.1
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• pp.55-59
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• 2004

This study developed a fully automated test system for pressure vessels, containing such as oxygen, nitrogen, which is widely used in many industries. The pressure vessel test has three major parts including weight measurement test, water-hydraulic test and leakage test followed by cleaning and drying. The control system for these tests consists of three parts: a PLC, a monitoring system and a database management system. The PLC oversees overall control of test machines, while the monitoring system measures and displays weight, pressure, flow etc. for every situations, and the database management system stores test data. These three modules are designed to communicate with one another at 1 Hz frequency alerting problematic situations to the operator. The system has gone through actual field tests for verification of performances.

• Journal of Power Electronics
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• v.16 no.1
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• pp.153-162
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• 2016

Given their structural arrangement, photovoltaic (PV) modules exhibit parasitic capacitance, which creates a path for high-frequency current during zero-state switching of the converter in transformerless systems. This current has to be limited to ensure safety and electromagnetic compatibility. Many solutions that can minimize or completely avoid this phenomenon, are available. However, most of these solutions are patented because they rely on specific and often complex converter topologies. This study aims to solve this problem by introducing a solution based on a classic converter topology with an appropriate modulation technique and passive filtering. A 5.5 kW single-phase residential PV system that consists of DC-DC boost stage and DC-AC H-bridge converter is considered. Control schemes for both converter stages are presented. An overview of existing modulation techniques for H-bridge converter is provided, and a modification of hybrid modulation is proposed. A system prototype is built for the experimental verification. As shown in the study, with simple filtering and proper selection of switching states, achieving low leakage current level is possible while maintaining high converter efficiency and required energy quality.

• Convergence Security Journal
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• v.17 no.2
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• pp.3-13
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• 2017

In the knowledge-information society, many domestic companies put lots of investment in technical development to possess core technologies and intellectual property. However, in the results of passive investment in security to protect their technologies compared to the active investment in technical development, the technology leaks from many companies and research institutes are rapidly increasing. Such increase of technology leaks not only causes damage to companies, but also has harmful effects on national economy directly and indirectly. Even though it has been perceived that a lot of industrial technology leak crimes are committed by former/current workers of small and medium-sized businesses, it is hard to find researches that mainly compare and analyze them. Therefore, this study aimed to understand the actual status of industrial technology leaks by analyzing cases of industrial technology leaks from 2014 to 2016 based on the type of victimized companies, corporate internal leakers' positions, matter of complicity, tools used for technology leaks, and motivation for technology leaks. Through the analysis in each type, the patterns and characteristics of industrial technology leaks were researched, and also the exploratory research on industrial security for the prevention of industrial technology leaks was conducted.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.357-359
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• 2003

This paper is for the transient analysis of instant short-circuit test equipment according to the test of tripping limits and characteristics under IEC 60947-2. The in-rush current is harmful to almost equipments and the exact testing is not made because of it. LGIS has a instant short-circuit test equipment, but it is not suitable for carrying out instant short-circuit test on ELB(Earth Leakage Circuit breaker) by reason of that. Now, I am going to show a solution for that problem. After applying this method, manufacturer is going to acquire the exact testing result according to the IEC standard. Moreover, Testing laboratory will be trusted by clients.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.519-522
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• 2002

In this paper, we analyze the impact of plasma etching process induced device degradation on low temperature poly-Si TFTs. The results indicate the relationship between device degradation and PPID effect during plasma fabrication. The dual-gate structure, which is used to suppress leakage current, is also discussed in this research.

• Journal of Korean Society for Quality Management
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• v.46 no.2
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• pp.301-310
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• 2018

Purpose: The purpose of this study is to investigate the effect of work intensity on fit factor and affective quality of the dustproof Background: Among the victims who suffer pneumoconiosis due to the inhalation of toxic substances or the lack of oxygen during the work, the proportion of the victims is larger than the other causes. Wearing a respirator may prevent pneumoconiosis, but it can be hazardous to workers because of the leakage through filters, cartridges, exhaust valves, broken parts, and face-to-face contact. Despite leakage through the contact area between the mask and the face has various causes such as the wearer's activity, sweat accumulation, facial shape, etc., There is a lack of relevant research and regulation compared to developed countries that have already institutionalized the law 30 years ago and give the right to sell through a test Method: The work intensity was adjusted by walking or running at 6km/h and 11km/h on the treadmill, and tasks were defined with reference to the test procedure and the exercise sequence applied in the face leakage test of the dustproof mask. And fit factor was measured objectively using 'Respirator Fit Tester 8038' which measures fit factor calculated by dividing the number of dust present outside the mask by inside the mask. In addition, affective quality was classified by the ease of use, ease of breathing, and ease of wearing, and was measured using the 5-point likert scale questionnaire. Results: There was a significant difference in fit factor, ease of breathing, and wearing convenience according to work intensity and no significant difference in ease of use(${\alpha}=0.01$). And when the work intensity was high, fit factor, ease of breathing, and wearing convenience were all lower than when the work intensity was low. Conclusion: In Korea, it is necessary to consider consideration of the work intensity when testing the leakage rate of the face part for safety certification of the respiratory protective equipment, When developing a mask, it should be possible to maintain high adhesion even under intense, active situation and high temperature conditions by selecting materials, improving the wearing style, and expanding the adjustable range.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.641-644
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• 2008

Traditional LTPS TFT needs additional LDD process to decrease leakage current. However the fabrication process is no suitable for PI substrate. Additional laser multi-irradiation will damage the poly-Si to cause the TFT electrical degrade. Therefore we propose the simplified process to activate the $N^+$ and $N^-$ at the same time.

• Design & Manufacturing
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• v.10 no.3
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• pp.8-13
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• 2016

Despite technological advance, there have been several troubles in photo reaction injection molding (photo RIM) to produce ultra thin light guide panels (LGPs). In this study, micro leakage problem at cavity edge during photo RIM was investigated numerically. In order to obtain optimal processing conditions, we regulated inlet pressure of injected resin at the cavity edge and figured out micro leakage behaviors. At low inlet pressure (less than 100 Pa), though the micro leakage problem was not occurred, another problem, short shot due to not enough driving force, was appeared More than 1,000 Pa of the inlet pressure, injected resin was rapidly leaked through the micro gap at the cavity edge. Finally, we obtained optimal inlet pressure around 600 ~ 1,000 Pa. At this region, injected resin fully filled the cavity without micro leakage behavior. Based on the present study, further comparative investigations with experimental photo RIM should be performed to find optimal processing conditions for produce ultra thin LGPs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.810-818
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• 2021

A leakage current of ESS is classified mainly by the occurrence from a PCS(Power Conditioning System) section and an unbalanced grid current. The reason for the leakage current from the PCS section is a voltage change by IGBT (Insulated Gate Bipolar Transistor) switching and stray capacitance between the IGBT and heatsink. The leakage current caused by the grid unbalanced current flows to the ESS through the neutral line of grid-connected transformer for the ESS with a three limb iron type of Yg-wire connection. This paper proposes a mechanism for the occurrence of leakage current caused by stray capacitance, which is calculated using the heatsink formula, from the aspect of the PCS section and grid unbalance current. Based on the proposed mechanisms, this study presents the modeling of the leakage current occurrence using PSCAD/EMTDC S/W and evaluates the characteristics of leakage currents from the PCS section and grid unbalanced current. From the simulation result, the leakage current has a large influence on the battery side by confirming that the leakage current from the PCS is increased from 7[mA] to 34[mA], and the leakage current from an unbalanced load to battery housing is increased from 3.96[mA] to 10.76[mA] according to the resistance of the housings and the magnitude of the ground resistance.

• The Journal of Society for e-Business Studies
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• v.20 no.2
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• pp.27-36
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• 2015

Current leakage of industrial technologies with revealing state secret against nation is gradually increasing and scope of the spill is diversified from technology-oriented leakage to new economic security sector like information and communication, electrical and electronic, defense industry, illegal export of strategic material, economic order disturbance by foreign country, infringement of intellectual property, etc. So the spill damage can affect not only leaked company but also national interests and entire domestic industry. According to statistics from National Industrial Security Center of National Intelligence Service, a major cause of technology leakage is not only by external things about hacking and malignant code, but internal leakage of former and current employees account for about 80%. And technology leakage due to temptation of money and personal interests followed by technology leakage of subcontractor is steadily increased. Most studies in the field of security have tended to focus on measuring security capability of company in order to prevent leakage core assets or developing measurement Indicators for management rather than security activities of the company members that is most important. Therefore, this study analyzes the effect of most underlying security education in security activities on security capabilities of enterprise. As a result, it indicates that security education have a positive(+) correlation with security capabilities.