• International Commerce and Information Review
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• v.6 no.2
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• pp.85-105
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• 2004

International electronic commerce is different with international commerce in the aspect using electronic media and non-face transaction so there are some problems as authentication, integrity and non-reputation. These problems of electronic document and signature are resolved from electronic certification system. To introduce and develop the electronic certification in the international electronic commerce, it needs to authorize and operate certification authority under the uniform regulation base. But, because the laws and guidelines that related to electronic certification system are different among the nations and international organizations, it needs to compare each nation's law or guideline. In conclusion, to resolve problems of certification and develop certification system in the international electronic commerce, we make uniform rule of international electronic certification and harmonize the technology of electronic certification.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.430-434
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• 2002

Recently, lot of researchers pay attention to custom power equipments for power quality improvement, especially, voltage stabilization equipment using PWM AC-AC converter. In this paper, voltage regulation system with PWM Buck-Boost AC-AC converter is proposed and then the system is modelled and analyzed by using of Circuit DQ transformation whereby steady state characteristics such as equations for voltage gain and power factor are obtained. The equations become guide line for system design by showing the effect on system operations. Finally, some experiment will show validity of analysis.

• Journal of Advanced Marine Engineering and Technology
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• v.26 no.2
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• pp.248-255
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• 2002

Miller cycle was studied and analyzed by engine performance simulation to achieve very low fuel consumption and to meet the IMO NOx regulation on a medium speed diesel engine. Based on the performance simulation results the intake valve closing time for HYUNDAI HiMSEN 6H21/32 engine was set at 0deg.ABDC(After Bottom Dead Center). Also, the simulation results indicated that significant NOx reduction could be achieved with low reduction of fuel consumption. The performance simulation investigated the effect of compression ratio and turbocharger on fuel consumption and NOx concentration in combination with Miller cycle. The results indicated a significant reduction of fuel consumption with keeping NOx concentration. The results of performance simulation were compared with measured data to verify simulation results. The comparison showed the maximum error was 2.34% in exhaust temperature. Also, the experimental result showed that improvement in BSFC(Brake Specific Fuel Consumption) was 5.8g/kwh with keeping NOx level similar to simulation result.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.269-274
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• 2005

This paper is studied on earth network configuration when common earth is applied to electrified railway system. And the permitted capacity of buried earth cable used for configuring common earth network and application plan of existing individual earth system when common em1:h network is applied to existing electrification line improvement are studied. For this, the configuration of common earth network is examined according to the SNCF regulation, and the interface between common earth and individual earth is analysed on the basis of the existing track circuit used in electrified line.

• The Journal of Fisheries Business Administration
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• v.44 no.1
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• pp.25-37
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• 2013

The permit system is the most typical regulation system in Korean fishery. Even now, it has caused resource management failure, it has also invited economic inefficiency and inequity. Accordingly, the Korean government has recently introduced the fishing boats market, it would be improve entry barrier for new capital and labor in fishing industry. This study aims to survey and to analyze the status of coastal fishing boat market using the executive documents on permit system in Gyongnam province. And also, this study put focus on improve fishing permit trade take advantage of the fishing boat trading. The survey results indicated that the number of fishing boats trading is estimated about 5,000 per year, however, fishing boat market is very narrow. An analysis on fishing permit trading showed that policy support is essential to reduce transaction cost. Therefore, it is necessary to explore corresponding policy tasks, this will be reduce transaction costs and sunk cost.

• Journal of the Korea Safety Management & Science
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• v.9 no.4
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• pp.1-9
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• 2007

The Korean government had enacted 'Special Regulation on the Safe Maintenance of Facilities' and carried out regular safety inspections since the mid-1990s, consequently establishing and enforcing an effective maintenance and management system. And throughout this entire process, the government searched for new methods to increase the overall effectiveness of the system. Nevertheless, the reality is that our society remains structurally unprepared to implement a commercial mindset that views the concept of "safety" as a product that can be traded in the open market based on supply and demand. Therefore, the government should establish mid to long-term plans to implement such a system in successive stages.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1210-1213
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• 2006

Indoor air quality is an important determinant of human health and comfort. However, the complexity of pollution sources and the multitude of parties responsible for creating indoor exposures makes the improvement of air quality difficult. The KTX HVAC(Heating, Ventilating and Air-Conditioning) system is important facility to provide comfortable environment passenger service. The Ministry of Environment is planning to enforce$\square\square$Indoor Air Quality Management law in Public Facilities$\square\square$in year 2008. Hereupon, the train and the subway are included. In this research air quality in the KTX Train compartment has measured. As a result, The average amounts of PM10(particulate matters), $CO_2$(carbon dioxide)measured $20{\mu}g/m^3$, 1,097ppm in KTX respectively. There are compare to regulation the value is 10% for PM10 and 43% for $CO_2$. Thus, the indoor air quality of KTX train have been proved satisfy the recommendation the Ministry of Environment guidelines.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.232-233
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• 2013

Recently Korea has imported and executed Performance Based Design for the method to settle the dangerousness on outbreak of fire of high-rise building. The overseas country's PBD is autonomic but It is unable to carry out the essential role of PBD as the performance based design that based the code based design in the domestic. Also It occurs the problems that different the classification standard of building as dualisation between the building code and the fire services act. In this study, We have investigated overseas's cases for the PBD of high-rise building and have drawn the improvement direction & the problem of domestic's PBD by comparing and the analysing the domestic regulation.

• Journal of Communications and Networks
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• v.18 no.4
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• pp.658-669
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• 2016

The tremendous increase in mobile data traffic coupled with fierce competition in wireless industry brings about spectrum scarcity and bandwidth fragmentation. This inevitably results in asymmetric-valued long term evolution (LTE) spectrum allocation that stems from different timing for twice improvement in capacity between competing operators, given spectrum allocations today. This motivates us to study the economic effects of asymmetric-valued LTE spectrum allocation. In this paper, we formulate the interactions between operators and users as a hierarchical dynamic game framework, where two spiteful operators simultaneously make spectrum acquisition decisions in the upper-level first-price sealed-bid auction game, and dynamic pricing decisions in the lower-level differential game, taking into account user subscription dynamics. Using backward induction, we derive the equilibrium of the entire game under mild conditions. Through analytical and numerical results, we verify our studies by comparing the latest result of LTE spectrum auction in South Korea, which serves as the benchmark of asymmetric-valued LTE spectrum auction designs.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.1
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• pp.163-170
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• 2012

Most of the cities and countries have distressed themselves about the urban social problem caused by the concentration of industry and population. Especially, disorderly expansion of cities and infrastructure improvement in rapid urbanization have also come into question. For this reason, proven urban planning facilities and tightened regulation on city planning are indispensible to solve these serious problems that we face. There are lots of similar studies to verify how to cope with a rapid urbanization.