• Journal of the KSME
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• v.33 no.5
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• pp.414-420
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• 1993

원자력 발전소의 운전환경에 따른 노화손상은 발전소 운전 내력에 연류된다. 통상SCC는 40년 또는 40년 이하의 수명을 가정하여 이에 따른 설계 여유도나 안전 계수를 기초로 하여 설계된다. 그러나 설계여유도나 안전계수는 운전중 변경될 수도 있다. 원자력 발전소 기기의 변경될 수도 있다. 원자력 발전소 기기의 수명평가를 위해서는 초기설계치 및 잔여수명이나 실제 설계치의 변화 등을 평가하여야 한다. 주요 물성치 및 손상 매개변수의 실제 변경 상황은 수명기간 설정에 근간이 된다. SSC의 수명평가를 위해 재료의 노화손상은 철저히 파악되어야 한다. 또한 기계적 하중, 열적하중 등의 노화 촉진요인과 정상운전 및 시험도 노화손상에 영향을 미치므로 이들에 대해 상세 평가를 수행하여야 한다. 수명평가는 운전환경 및 노화촉진요인들과 밀접한 관련이 있으므로, SSC의 수명을 평가하기 위해서는 이러한 복잡한 변수들 사이의 연관관계를 구체적 으로 고려하여야 한다. 그러므로 SSC의 수명을 평가하기 위해서는 이러한 복잡한 변수들 사이의 연관관계를 구체적으로 고려하여야 한다. 그러므로 SSC의 설계, 제작, 설치, 시험, 운전상태 및 보수주기 등에 대한 정보파악이 선행되어야 한다.

• Natural Product Sciences
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• v.25 no.4
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• pp.293-297
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• 2019

Policosanol extracted from sugarcane wax is a generic term used for total fatty alcohols obtained from esterification of fatty acids. It has been approved as a health functional food by the Ministry of Food and Drug Safety of Korea in 2006. Policosanol is well-known to aid in lowering blood cholesterol level. Recently, several studies have reported the physiological activities of policosanol, such as anti-inflammatory effects, antioxidant effects, and lowering of the incidence of ageing-related diseases, for example, hypertension, stroke, among others. This review describes the physiological activities of policosanol and its applications in the field of health functional foods.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.5
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• pp.241-246
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• 2015

Cellular foamed insulation such as polyurethane foam ages and degrades the thermal conductivity. Aging of foam is a result from the diffusion of gases, initially consisting of $CO_2$ but eventually replaced by air from the environment. The variation of the cell gas content with time is primarily influenced by the increase of thermal conductivity of the cellular foam. The weight of foam also changes as the gas diffuses and exchanges. In this study, a weight measurement method has been proposed to evaluate the effective diffusion coefficients of $CO_2$ and Air, $D_{CO2}=7.08504E-11$ and $D_{air}=4.86086E-12$, respectively and are compared with the gas analysis method.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.309-314
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• 2000

Rubber is used as a primary suspension component in a vehicle or a mechanical structure. The aim of this study is to establish a procedure for measuring the material properties of rubber and to analyze the differences of material properties of virgin rubber and heat aged rubber. The effect of mechanical conditioning was shown and included in the procedures of tensile. compression. simple shear. and pure shear tests. In addition. using engine oil was recommended for compression test in order not to have barrelling. Moreover, based on the material properties of vil·gin rubber and heat aged rubber. equations of C10 and IRHD were proposed as a function of heat aging temperature and time.

• The Korean Journal of Community Living Science
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• v.25 no.1
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• pp.29-37
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• 2014

This study examines whether regular exercise moderates the relationship between hand grip strength and cognitive function in older adults. Older adults 65 and over from the third wave of the Korean Longitudinal Study of Ageing Data were analyzed. A moderated multiple regression analysis was conducted to assess the moderating effects of regular exercise on the relationship between hand grip strength and cognitive function. According to the results, regular exercise moderated the effects of hand grip strength on cognitive function, suggesting that regular exercise should be promoted for older adults to reduce unfavorable effects of a decrease in hand grip strength on cognitive function.

• Communications for Statistical Applications and Methods
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• v.2 no.2
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• pp.20-32
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• 1995

The concept of positive ageing describes the adverse effects of age on the lifetime of units. Various aspects of this concept are described in terms of conditional probability distribution of residual life times, failure rates, equilibrium distributions, etc. In this paper, we will consider some partial ordering relations of life distributions under residual life functions and equilibrium distributions. Under residual life distributions, we study the relationships of IFR, NBU and NBUFR classes and that of DMRL and NBUE classes, By using WLR ordering comparison between F and its equilibrium $H_F$, we can decide if F belongs to NBUFR class.

• Korean Journal of Organic Agriculture
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• v.20 no.4
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• pp.563-576
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• 2012

The Purpose of this paper is to establish development strategies for sustainability of environment-Friendly agriculture based on farm awareness analysis. To analysis farm management, a series of farm household surveys were conducted on farmers residing in Embong-Myun. The sample size of the survey is 108 respectively. As a survey result, satisfaction level about market stability and understanding of upper organization is high, on the contrary, awareness of related organization is low in a relative sense. Most of farmers reveal their intention to sustain environment-Friendly agriculture but future agriculturalist and an ageing society that one face as well. In order to establish development strategies for sustainability of environment-Friendly agriculture, an infrastructure should be consistently expanded. On the other hand, self-supporting ability of farmer's organization and education system attempt to expand for sustainability.

• Analytical Science and Technology
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• v.17 no.3
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• pp.271-277
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• 2004

The aim of this study was to investigate questioned documents written with blue or black ballpoint pen on paper by nondestructive technique. In this work, 21 blue and 22 black ballpoint pen inks which were purchased on different brands were analyzed by using Microspectrophotometry (MSP). The reflectance spectra were obtained from these ink samples and their shapes and the wavelength of the maximum intensity were compared. In the blue and black ballpoint pen inks, the discriminating powers (DP) were 0.85 and 0.61, respectively. The changes of the reflectance intensity at their wavelength of maximum intensity and their shapes appeared according to the exposure time to sunshine in a laboratory, especially in the blue ballpoint pen inks. Therefore it is possible to distinguish ink entries on the same paper with the relative age in case of questioned letters written with blue ballpoint pen.

• Textile Coloration and Finishing
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• v.24 no.1
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• pp.54-61
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• 2012

This study surveyed the preparation of 8oz coated fabric and the physical property of the coated fabric according to the treated condition for the sail yacht. And the coated fabrics were compared with the performance of overseas products for verification. Physical properties of the coated fabric treated with non-yellowing functional polyurethane resin were examined according to the treatment condition such as compression and ageing treatments. Finally, yellowing fastness to light for 60 hours was assessed. Considering the compression condition after coating, good physical property was obtained at $6kgf/cm^2$. Also, the performance of yellowing fastness was similar to performance of overseas goods.

• Fibers and Polymers
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• v.7 no.2
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• pp.105-111
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• 2006

Coating the fibre surface by in situ oxidative chemical polymerisation of polypyrrole (using $FeCl_3$ as oxidant) is a readily industrial applicable way to give electrical properties to wool with good ageing stability [1], although pre-treatments are required to avoid damage of the cuticle surface due to the acidic condition of the process. FT-IR and EDX analysis reveal that organic sulphonates and sulphates, used as dopants, are absorbed by wool, while chlorine ions are preferably embedded on the polypyrrole layer. The resulting electrical conductivity seems mainly due to the presence of chlorine as counter-ion of polypyrrole; nevertheless, the presence of arylsulphonate in the polymerisation bath increases the electrical conductivity of the coating layer.