• 전기의세계
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• 제27권6호
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• pp.54-57
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• 1978

An analytical investigation has been carried out for the motion of moving element in electro-dynamometer type directional power relay under A.C source. For the more a time dependent kinetic performance of the element can also be deduced for the D.C component in fault current. The results obtained thus for show that, in the relay with stopper, the performance time for the equal D.C and A.C component can be shorten ca. 0.5Hz in comparison with the fact, the performance time exhibits to delay ca. 0.75Hz under the same conditions for the case of the relay without stopper, it appear that these differences of performance times will not give vise any difficultys for the apects of practical case, however, the obtain results can be applicable in the course of the design of the relay.

• 대한전기학회논문지:전력기술부문A
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• 제49권9호
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• pp.459-466
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• 2000

The performance of a commercialized power system stabilizer (PWX-600) for a single hydro-turbine generator and infinite bus system has been investigated using Real Time Digital Simulator (RTDS) in this paper. The test system was composed of RTDS, three phase voltage/current amplifier and the PSS. The test scheme provided a very efficient way to verify the design and control performance of a PSS to be applied to real power system. The scheme can also be applied to verify in real time the performance of hardware and software of power system controllers for FACTS and protective relays effectively.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.201-203
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• 2011

The purpose of this study was to develop and evaluate of fire resistive cladding systems for HSC(high-strength concrete) column, which was mainly constructed with aerogel blanket insulation material. The aerogel blanket-fire protective gypsum board cladding system showed that it clearly secure the fire resistance performance of HSC column when the reinforcing measures had achieved for four cross-sectional edge sides of structure and the system is well continued during the test period with no significant deformation or separation etc. It was checked out the 20mm thickness cladding system consist with AG(5mm)+FGB(15mm) can secure 3hour-fire resistance performance adequately.

• Nuclear Engineering and Technology
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• 제37권3호
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• pp.221-230
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• 2005

This paper reviews the pivotal phases of the evolution of the current technology-dependent nuclear power safety regulation in the United States. Understanding of this evolution is essential to the development of any future regulatory paradigm, including the technology-neutral regulatory approach that the U.S. Nuclear Regulatory Commission (NRC) has recently embarked on to develop. The paper proposes and examines the implications of a predominately rationalist and best-estimate probabilistic regulatory framework called safety goals-driven performance-based regulation. This framework relies on continuous assessment of performance of a set of time-dependent safety-critical systems, structures and components that assure attainment of a broad set of technology-neutral protective, mitigative, and preventive goals. Finally, the paper discusses the steps needed to develop a corresponding technology-neutral regulatory system from the proposed framework.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.821-824
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• 2004

For nuclear concrete structures on the coast, the prevention and management against salt damage is needed because they are being under the influence of the sea water at all times. In general, the deterioration of the concrete is generated in concrete surface firstly and then extended into concrete gradually as its service life increases. Therefore, the protective layer on the concrete surface is needed to establish and manage the durability of concrete. To enhance the durability performance of the existing and new concrete, the development and application of a high-performance penetration sealer is needed. The sealer has to have the functions that are able to prevent the attack of the moisture, carbon dioxide, and harmful substance from the outside. Therefore, the aim of this study is to development of a sealer for the long service-life and waterproof performance of a nuclear concrete structures.

• 운동영양학회지
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• 제23권2호
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• pp.13-15
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• 2019

[Purpose] Functional beverages are a protective or enhancing factor influencing not only public health but also athletic performance. The purpose of this study was to highlight the new conditioning beverage of the Lactobacillus pentosus strain b240 (B240) with electrolytes or proteins, which strengthens immune functions to improve the quality of life. [Methods] ISeveral related studies systematically reviews three main issues associated with conditioning beverages: (a) utilization and availability of the functional beverage; (b) significance of B240 in immune strengthening; and (c) availability and application of conditioning drinks in the daily life and sports field. [Results] Intake of B240 led to greater enhancements, including blood T-helper, NK cell, IgA and IgG level in conjunction with strengthen immune functions. These results speculated that the practical application of B240 contained beverages on physiological health and performance. [Conclusion] BODYMAINTÉ, this novel conditioning beverage is expected biological utility responsible for improved sports performance as a functional drink and has potential health-related implications.

• 한국안전학회지
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• 제27권5호
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• pp.30-34
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• 2012

A safety helmet is a personal protective equipment to protect the head from falling and flying objects. A safety helmet has the maximum delivered impact force as shock absorption performance, the lower delivered impact force the better performance, which was not a controlled variety during manufacturing safety helmet. Accordingly there were some difficulties in establishing the standard for improved performance as there was not a clear controllable impact force for improved performance. In this study the shock absorption performance was intended to be found as coefficient of restitution related to impulse. As a research method, a coefficient of restitution during the absorption of shock was calculated using the impulse transferred to pharynx utilizing the safety helmet shock absorption performance testing device based on the theory of momentum and impulse. The estimated impulsive force curve was derived assuming that shock was not absorbed using the measured data. The sample was selected as tested goods of ABS material for safety certification available mainly in the market. As a result of study, the maximum delivered impact force of safety helmet made by a domestic safety certified a company was 735 N, and its coefficient of restitution proved to be 0.64. The smaller coefficient of restitution is, the lower maximum delivered impact force and the higher shock absorption performance. The coefficient of restitution can be used as a performance index of safety helmet.

• Advances in aircraft and spacecraft science
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• 제4권1호
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• pp.37-52
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• 2017

Gas turbines operating in dusty or sandy environment polluted with micron-sized solid particles are highly prone to blade surface erosion damage in compressor stages and molten sand attack in the hot-sections of turbine stages. Commercial/Military fixed-wing aircraft engines and helicopter engines often have to operate over sandy terrains in the middle eastern countries or in volcanic zones; on the other hand gas turbines in marine applications are subjected to salt spray, while the coal-burning industrial power generation turbines are subjected to fly-ash. The presence of solid particles in the working fluid medium has an adverse effect on the durability of these engines as well as performance. Typical turbine blade damages include blade coating wear, sand glazing, Calcia-Magnesia-Alumina-Silicate (CMAS) attack, oxidation, plugged cooling holes, all of which can cause rapid performance deterioration including loss of aircraft. The focus of this research work is to simulate particle-surface kinetic interaction on typical turbomachinery material targets using non-linear dynamic impact analysis. The objective of this research is to understand the interfacial kinetic behaviors that can provide insights into the physics of particle interactions and to enable leap ahead technologies in material choices and to develop sand-phobic thermal barrier coatings for turbine blades. This paper outlines the research efforts at the U.S Army Research Laboratory to come up with novel turbine blade multifunctional protective coatings that are sand-phobic, sand impact wear resistant, as well as have very low thermal conductivity for improved performance of future gas turbine engines. The research scope includes development of protective coatings for both nickel-based super alloys and ceramic matrix composites.

• 한국치위생학회지
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• 제16권2호
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• pp.215-224
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• 2016

Objectives: The purpose of the study was to investigate the related factors of performance of radiation safety management in dental hygienists. Methods: A self-reported questionnaire was completed by 183 dental hygienists using dental radiography in 110 dental clinics in G area by convenience sampling methods. The questionnaire consisted of general characteristics of the subjects, radiation-related characteristics, and performance and management of radiation safety. Results: Performance score of radiation safety management was $35.71{\pm}12.49$ in dental hygienists. The performance score of radiation safety management were associated with sex, numbers of dental hygienists, the average numbers of admitted patients per day, the total clinical experience, existence of manual for radiation safety management and perceived need for education of radiation safety management. Conclusions: The performance score was relatively low. The performance score was associated with radiation safety manual and safety equipment. The preparation of radiation protective environment and equipment will improve the performance of radiation safety management in dental hygienists.

• 한국융합학회논문지
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• 제13권3호
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• pp.91-103
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• 2022

본 연구는 COVID-19 발생 전후에 작업치료를 수행하고 있는 작업치료사 101명을 대상으로 손 씻기, 개인 보호 장비 사용, 주변 환경 정리의 감염관리에 대한 인식과 수행을 비교하고자 설문조사를 실시했으며, 맨-휘트니 U 검정(Mann-Whitney U test), 크루스칼-왈리스 H 검정(Kruskal-wallis H test), 윌콕슨 부호 순위 검정(Wilcoxon signed-rank test), 피어슨 상관분석(Pearson's correlation coefficient)을 사용해 분석하였다. 그 결과, COVID-19 발생 이전보다 발생 이후에 감염관리 교육을 더 잘 받았고 감염성 질환의 경험이 낮은 것으로 확인되었다. 또한, COVID-19 발생 이전보다 발생 이후에 손 씻기, 개인 보호장비 사용, 주변 환경정리에서의 감염관리에 대한 인식 및 수행이 향상된 것으로 나타났다. 하지만 현재까지도 질병관리청에서 권고하는 흐르는 물에서 40초 이상의 손 씻기와 치료실 청소 및 치료 도구의 소독은 개선이 필요한 실정이다. 본 연구를 통하여 감염성 질환의 발생을 최소화하기 위해 감염관리 교육을 정기적으로 반복해야 하며, 향후 작업치료사를 대상으로 하는 감염관리 교육 및 후속 연구에서 활용할 수 있는 기초자료가 될 수 있을 것이다.