• Explosives and Blasting
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• v.38 no.2
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• pp.22-35
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• 2020

Recently, electronic detonators have been widely used in various sites. Electronic detonators are often used for the purpose of reducing the noise and vibration produced by blasting. In addition, electronic detonators are used for precision blasting at sites where mechanical excavation techniques are applied due to proximity of safety things or where blasting by conventional detonators are not possible. Various technologies are being attempted at the blasting site to increase constructivity and lower production costs by using electronic detonators. In this paper, we would like to introduce a construction case that use of electronic detonators in the situation of safety things being adjacent increases the efficiency of construction while meeting the ground vibration criteria of Ministry of Land, Infrastructure, and Transport. The blasting was carried out at domestic and overseas shaft using HiTRONIC II™, produced by Hanwha. Generally the shaft blasting is performed by dividing the blasting surface because of the noise and vibration caused by the blasting. but, in the case introduced in this paper, the blasting was carried out once without dividing the blasting surface, thus the construction period could be shortened.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.10
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• pp.1328-1336
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• 2014

This paper proposes Power System Health Index(PSHI) newly. The paper describes several kind of power system health indices based on two main categories, which are adequacy and security. In adequacy, four kinds of health indices of Frequency, Voltage, Reserve(Operating Reserve Power and Frequency Regulation Reserve Power) and Overload of lines and transformers are proposed. In security, four kinds of health indices of Voltage(154kV, 345kV and 765kV), Overload of lines and transformers, Power flow constraint among areas and SPS are proposed. All indices are mapped with three domains, which are indicated as Health, Margin and Risk, defined with expert interview. While domains of health, margin and risk is defined similar with the conventional well being analysis of power system. The criterion of the domains is proposed using an interview with expert operators and practical reliability codes in Korea. The several kinds of health index functions, which are linear ratio, piecewise linear ration and reverse ratio function etc. are developed in this paper. It will be expected that the developed health indices can help operators to control power system more successfully and also prevent power system from accident as like as black out in future because operator can make a decision immediately based on more easily visual information of system conditions from too much indices acquisition of complex power system.

• Journal of Digital Convergence
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• v.9 no.4
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• pp.19-28
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• 2011

Nowadays Several Countries like USA and Republic of Korea introduced Electronic Litigation System in the civil sector, and this introduction of electronic system affected several changes dramatically management environments of many firms. Especially in Republic of Korea this electronic litigation system is introduced by the purpose such as decrease paper document, cost down of litigation and the transparence, but till now most enterprises don't prepare about electronic litigation. This introduction of electronic litigation system changes the circumstance of the law environment, firms have to prepare solutions about changes of litigation systems and changes of firma management systems.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.143-146
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• 2004

Signals of the short wave part of centimetre, millimetre and optic wave length ranges are being broadly used in the communication, location and remote sensing systems with space channels. In this case the presence of discrete non-uniform mediums like orbital debris, space dust and other discrete formations in the propagation channel may have substantial influence upon the characteristics of wave processes. and thus upon the data system quality. Mathematical models for studying the discrete non-uniform mediums effect on the characteristics of electromagnetic wave propagation are analyzed in this paper.

• The Journal of Society for e-Business Studies
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• v.8 no.3
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• pp.143-164
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• 2003

Because of the wide scale in EC area, the use of Electronic Commerce spreads out quickly. This paper proposes the curriculum applied to the department of EC in University reflecting the recent social trend. EC has some relations with the several areas like Computer Science ＆ Engineering, Management and Industrial Engineering etc. after analyzing the domestic curriculums, we propose the propriate curriculums and academic classification standard. Also according to the standard, We want to propose the separate curriculums to three important majors and describe the introduction to each major.

• Journal of electromagnetic engineering and science
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• v.5 no.1
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• pp.31-35
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• 2005

This paper presents low form factor dual polarized antenna incorporating low profile annular ring patch antenna having 90$^{\circ}$ phase delay element for circular polarization(CP) and a reactive-loaded monopole linear polarized(LP) antenna. Both types of receiving antennas operate in the same frequency region from 2.320 GHz to 2.345 GHz, while different polarizations are used to take advantage of polarization diversity. The proposed CP antenna has good broadside radiation patterns, while the LP antenna reveals monopole-like radiation patterns. The gains of the antennas are measured to be 1.93 dBi and 2.24 dBi for CP and LP, respectively.

• 한국정보교육학회:학술대회논문집
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• 2010.08a
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• pp.221-226
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• 2010

Culture is like living organisms based on local and history. Therefore, we don't understand the whole phase of the culture if we neglect the information of the time and space. In this paper, we describe a preliminary study building of a 3D electronic cultural atlas about the national education center for Korean traditional music.

• Journal of Electrical Engineering and Technology
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• v.10 no.4
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• pp.1796-1803
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• 2015

While considering the current scenario, in this world power demand goes on increases day by day. Frequent power outages occur in high voltage transmission line due to the deprived performance of polluted insulators; this affects overall operation of power system and may indirectly impinge on the growth of production sector. Many researchers are keenly taking efforts to provide highly reliable and stable power to neediest. In this paper, A.C pollution flashover performance of disc type glass insulator and composite long rod insulators investigation under various artificial pollutions by varying Equivalent Salt Density Deposition (ESDD) levels. Here, we use different types of pollution methods like binding method, dipping method and spraying methods with different types of pollutants concentration. Based on dimensional analysis, four different Mathematical models have been developed to predict the A.C pollution Flashover Voltage (FOV) of insulators. Both the experimental and mathematically modeled results are compared; it's observed that mathematical model 3 yields better results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1993.11a
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• pp.93-96
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• 1993

BiCMOS technology, which combines CMOS and bipolar technology, offers the possibility of achieving both very high density and high performance. In this paper, the characteristics of BiCMOS and CMOS circuits, especilly the delay time is studied. BiCMOS inverter, which has high drive ability because of bipolar transistor, drives high load capacitance and has low-power characteristics because the current flows only during switching transient just like the CMOS gate. BiCMOS inverter has the less dependence on load capacitance than CMOS inverter. SPICE that has been used for electronic circuit analysis is chosen to simulate these circuits and the characteristics is discussed.

• Transactions on Electrical and Electronic Materials
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• v.4 no.3
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• pp.25-28
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• 2003

Radiation technology is an effective way for regulating polymeric materials to physicochemical and mechanical properties. New polymeric hydrogels based on vinyl ethers have been synthesized by the $\gamma$-initiated polymerization method. In this paper, we have studied the effect of radiation on mechanical and electrochemical properties of new rubber-like polymeric composite materials based on polyvinylether of ethyleneglycol (PVEEG).