• Journal of Family Resource Management and Policy Review
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• v.12 no.1
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• pp.57-89
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• 2008

Using the data of 'middle-and old-aged people' in the 6th year(2003) of KLIPS(Korea Labor and Income Panel Study), this study compared entirely retired men's income source and amount of income divided by the time of retirement and analyzed the determinants of main income source and amount of income level using Multinomial Logit Analysis and Tobit Analysis. The results of these were as following; First, Entirely retired men has average 1.27 income source and the amount of income from main income source is positioned at 85% of total income. This result indicates the lack of variety to get opportunities of income sources for the living and also means high risk associated with the entirely retired men if he looses the main income source. Second, most of income source of entirely retired men is spouse's earned income or private income transfers, however, if we divide those as timing of retirement and characters of each individual, it is represented that the most of income source is differentiated by the position at labor market during work life and the opportunity for building the wealth, and the possibility of obtaining public pension and public support. Third, the income level depends on what sort of income source the retired men has, this shows that there is not a strong relationship between obtaining a Income source and gaining above the certain level of income.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.518-523
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• 2009

Main source of URN(Underwater Radiated Noise) which is related to the ship's survivability is divided into two groups. Cavitation is main source of URN when the speed of ship is upper than CIS(Cavitation Inception Speed). But when the speed of ship is lower than CIS, main source of URN is structure-borne noise on the hull which is originated from propulsion system, pump system or transmitted vibration of pipe system. In this paper, to reduce the vibration of discharge pipe and valve system, back flow prevent globe valve and new rubber mount are applied to the ship. As the result of applying new valve and mount, the vibration is reduced drastically.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.6
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• pp.599-606
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• 2009

Main source of URN(underwater radiated noise) which is related to the ship's survivability is divided into two groups. Cavitation is the main source of URN when the speed of ship is upper than CIS(cavitation inception speed). But when the speed of ship is lower than CIS, the main source of URN is the structure-borne noise on the hull which is originated from propulsion system, pump system and trnasmitted vibration of the pipe system. In this paper, to reduce the vibration of discharge pipe and valve system, back flow prevent globe valve and new rubber mount are applied to the ship. As the result of applying new valve and mount, the vibration is reduced drastically.

• Journal of Environmental Science International
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• v.18 no.8
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• pp.927-932
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• 2009

Wind turbine noise become main environmental problem as wind energy have been installed all around. Noise from large wind turbine give annoyance to listener, moreover it increase loading to whole system by restricting blade tip speed. However accurate noise mechanism of wind turbine is not yet examined. This paper reviewed noise source and analysis theory. Broadband noise if main component of wind turbine noise and airfoil self noise is main noise source. These make acoustic analogy hard to apply for analysis. For this reason, experimental equation is method for wind turbine noise prediction up to now. Spectrum analysis shows that vortex shedding noise exists around $1k{\sim}2k$ Hz. This region is most sensitive frequency range to human. Thus it is necessary to reduce this noise source.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.6
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• pp.927-935
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• 1994

Detailed analysis of the commutation circuit of the proposed wide-frequency current source inverter is given. In this inverter a spike-limit circuit and a precommutation circuit are used. The spike-limit circuit is intended to limit spike voltage which is arising during commutation time in a current source inverter, and the precommutation circuit to reuse the energy which flows from main inverter to spike-limit circuit during commutation time to aid commutation. Thus voltage stress of main thyristor is minimized. Since this inverter can be made up of thyristors for phase control, it has some advantage in high voltage and high power application.

• Journal of Technology Innovation
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• v.14 no.2
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• pp.117-141
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• 2006

The paper describes the status and context of the Chinese Open Source Software (OSS) industry and ecosystem based on the analysis of the components of the China OSS Promotion Union. The analysis involves comparisons of several main Chinese developers of Linux operating system and makers of open source counterpart of the popular Microsoft Office package as well as several main Chinese OSS communities. Comparisons concern the technological and business aspect. The findings reveal peculiarities of the divergence of innovative activities of Chinese companies, as well as indicate that the strong government support may at the same time limit the technology selection under rigid competition, especially as foreign open source companies are found to be more focused on hobbyist developers and are able to maintain larger independent communities. Implications of the paper include the need to coordinate global development efforts and adjust science & technology policies in order to stimulate both the development and the diffusion of open source among Chinese companies and individual hobbyists.

• Journal of Power System Engineering
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• v.7 no.3
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• pp.23-28
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• 2003

In heavy nuclear power plant, high energy through main steam line is provided to turbine that generate the electric power. Since plant had generated power, high noise has been occurred. Noise make equipments and work environment worse. For finding out the location and the cause of making noise, noise was measured along main steam line at open/close test of Main Steam Isolation Valve (MSIV hereafter). As the result, it was identified that the vortex shedding in the cavity of MSIV is main noise source. The profile change of MSIV seat ring was proposed as the method of noise reduction. After filletting MSIV seat ring, the noise level reduced $10{\sim}20dB$ compared before the change of profile.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.513-518
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• 2003

Noises are defined as unwanted sound and invoke the physical harm and unconvenience. The higher the noise level is, the more damage peoples have. Low frequency noise is less harmful than high frequency one. In case of train, noises inside of train which is isolated from outer circumstances reduce the convenience of passenger very much. This paper reviewed the noise standard of train for urban subway and investigated the main transformer as the main noise source of train and suggested the method to diminish the noise resulted from main transformer of train and compared the measured results of before and after the improvement of main transformer.

• The Journal of the Korea Contents Association
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• v.18 no.4
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• pp.575-585
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• 2018

The side effects of drug is closely linked to the people's health and professional. In this case, press report is very important in evaluating the side effects of drug and people's attitude of government's health policy. This study analyzed press report on the side effects of drug based on the main theme, source, responsibility attribution on crisis, frame and network analysis. Theses is a difference of main theme between the press. Daily newspaper focused on the occurrence of crisis and economical newspaper focused on the manufacture company. Professional paper focused on the criticizing of the health policy. The main source of the press on the side effects of drug is the Congressman. There are few articles which mentions about the crisis responsibility. However most articles mentioned that the subject of crisis solutions is the manufacturer. This study found the main meaning by network analysis. This study highlighted the government's crisis management based on the result of content analysis and network analysis.

• Journal of Korean Medical classics
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• v.19 no.2 s.33
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• pp.1-10
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• 2006

The main purpose of this essay is to shed light on the foundation of the core notion used in oriental medicine. Under the premise that the important notion of oriental medicine has its origin in the culture of the ancient china before B.C.$2^{\sim}1$, we will get to the source notion of oriental medicine by retrospecting the analogical thinking used in the course of forming the main notion of oriental medicine. For the source notion being in various domains, we must search so many domains for example the political system including the offical system, the economic system and so on. But in this essay, we will limit the domain concerned with combat.