• Journal of the Korean Ceramic Society
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• v.19 no.4
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• pp.300-308
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• 1982

A new perovskite type compound, (Pb1a-χKy□χ-y) (Zr0.33Ti0.67)O3-χ+y/2 was proposed and synthesized by "Wet-Dry Combination Technique". This defect ferroelectric material was characterized by partial substitutions of K+ for Pb+2 in Pb(Zr0.33Ti0.67)O3. This material was mono-phasic perovskite compound at 800℃ for 1hr., but ZrO2 was more or less isolated from the (Pb1a-χKy□χ-y) (Zr0.33Ti0.67)O3-χ+y/2. As a result, snitering temperature, sintered density, curie temperature, and dielectric constant of test pieces decreased and a-axis was nearly constant, while c-axis gradually decreased with the value x in the region of tetragonal phase of PZT. It was also recognized that the defect structure caused by adding K+ was found in both A-site cation and O-site anion vacancies in the defect PZT.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.138-141
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• 2008

The effects of design parameters for small scale hydro power(SSHP) plants due to rainfall condition have been studied. The model to predict hydrologic performance for SSHP plants is used in this study. The results from analysis for rainfall conditions based on Weibull distribution show that the capacity and load factor of SSHP site had large difference between the variation of shape and scale parameter. Especially, the hydrologic performance of SSHP site due to variation of shape parameter varied more sensitive than the case of variation of scale parameter. And also, the methodology represented in this study can be used to decide the primary design specifications of SSHP sites.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.34
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• pp.135-156
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• 2007

Trade Portal Site(TPS) is one of the essential tools which can make it possible for small and medium enterprises(SMEs) to perform international trade activity more efficiently using newest information and communication technology including the Internet. Therefore, Korean SMEs need to utilize TPS more actively to enhance their export competitiveness. In this context, this article analyzes the determinants of export performances of Korean SMEs in utilizing the service of TPS based on the Service Quality Model. As a result of an empirical research by using regressive analysis, various measures of service reliability such as reliability, empathy, and tangibilities have positive effects on SMEs export performance in utilizing TPS. These results provides many useful implications to the TPS managers, e-trade related government agency, along with managers of SMEs using TPS.

• Journal of Korean Society for Atmospheric Environment
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• v.2 no.1
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• pp.41-54
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• 1986

Methods used for averaging PH's of rainwater and site representation have been studied, Statistical analysis was attempted regarding effects of ionic components on PH's utilizing 847 data altogether obtained in two years, 1984 and 1985. The outcome of the study may be assumarized as follows: 1. Methods for Averaging PH Volume weighted method is considered to be acceptable providing that precipitation is measured at the same time when the samples are taken. Without precipitation data a simple averaging method should be the next choice. 2. Site Representation A statistical method used for optimizing a monitoring newtork was applied using the data collected. Because of a limited number of data, no discernible conclusion can be reached suggesting that the method can serve as a good guide when the data base becomes more reliable. 3. A good correlation appears to exist betwen conductivities and ionic components in rainwater. It would, therefore, be possible to certain extend to estimate ionic concentrations from conductivity measurements by correlation equations. 4. The acidity of rainwater is effected by $SO_4^{2-}, NO_3^-, Cl^- and NH_4^+ with SO_4^{2-}$ being the most significant as demonstrated by standardized regression analysis.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.6
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• pp.121-131
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• 2012

Many of the falling which is the number one risk factor in lethal accidents in construction could have been prevented if the right activity or supervising had been taken in time. All other measures do not preventive the fall, but rather intercept the fallen itself or preventive severe injury. The most common and the bets measures on the preventive measures are guardrails which are to be worn on the site. Workers always exposed the risk of serious accidents induced by causal effects related with environments around construction sites. In order to represent how to decrease the risk of workers, this study was accomplished with a number of interview with experienced site director, cheief of instructors, workers. And the questionaire survey (2012. 5~2012. 10) were used to make proposed policies which are expected to reduce critical disastrous accidents and strength authorized limits of director's management automatically.

• Proceedings of the Safety Management and Science Conference
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• 2000.05a
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• pp.55-60
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• 2000

In recent dates, Internet advertising effects are expanded by the steep increment of the Internet users and the extension of the advertising market will be accelerated through Internet. This paper indicates the importance of Internet advertising and suggests the solution of a network advertising service. The system Is divided into an Advertise Server, an Advertiser and a Web Publisher. This study proposes both the collection and the analysis of traffic data in real time. Also, the banner advertising frames are smoothed for the impression using the solution for the banner exchange engine and are developed using various impression methods, that is, Fixed/variable Banner, Scheduling Banner, Multi-Impression Banner, and Frame Remote Control to increase the advertising effect. And then to increase the advertising effect web publisher, which is specialized in lottery site, is constructed using the network advertising service and various advertising technology.

• Journal of the Korean Home Economics Association
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• v.38 no.1
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• pp.171-183
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• 2000

The purposes of this study were to identify the needs for the employer-supported day care service and to analyze the factors related to the needs for the day care service of the married employees. KLFI(1995)'s National data were used and three Logistic models and one Catmod model were employed to analyse the effects of the independent variables on the needs for the day care service. The results of this study were as follows: First, half of employed workers needed the employer-supported child care service. Second, they preferred the day care center near their residential area than in their work site. Third, according to their age, type of occupation, and their difficulties for the childcare and household work, employed men and women needs on site day care differently. Finally, their needs for the expenditure of duty care service differed by their age, sex, and occupation, and their levels of difficulties for the childcare and household work. These findings suggest that duty care service for the employed man and woman are supported diversely according to their needs and preferences.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.40-41
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• 2014

Today, the potential safety risk is increased due to a construction industry is high-rised, mechanized, and complexed. Most workers injured in accident caused by lack of safety awareness. Therefore the safety education is focused in construction site, but it can not get workers' interest and has many problems to reduce construction accident. This study will investigate the effects of education used BIM intended for workers in construction site to verify the objective effectiveness in future.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.9-14
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• 1998

In this paper, we described the basic elements(flowabiligy, fillingability, elapsed time, pumpability, no-vibrating effects, and etc.) required for the application and quality control of the super flowing concrete(SFC) in Top Down site. Also, manufactured sand and fly ash were used for investigating characteristics of SFC through various experiments(mix design, optimum mix condition) before placing the concrete in site. As a result of this project, the developed SFC shown high flowability and self-fillingability in the joint good enough for the requirement. Futhermore, inner uniformity of the no-vibrated concrete was verified by testing reformed space. Therefore, quality control and compressive strength(360kg/$\textrm{cm}^2$) can be secured by using SFC even without vibrating.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.17-26
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• 2001

The fatigue strength of SM55C has significantly decreased by 83% compared with atmosphere where distilled exists due to strong erosive action of acid fog. The reason is inferred in a way that strong acid erosive material such as acid fog act and give rise to multi-site crack on the surface. Several fatigue clacks occurred under the acid fog repeat the process of division and unification on the surface and form a long non-propagating crack throughout the circumference of experimented steel. However, in the depth, many parts do not show much trace of unification, and the depth is not as big as the one of normal crack shape. 10% of $CaCl_2$ causes strong erosive reaction to material. Then eventually make the life of fatigue shooter. On the other hand, 20% of $CaCl_2$ beings about oxidized material organic crack closing due to weak erosive reaction.