• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2008년도 추계학술발표논문집
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• pp.53-55
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• 2008

대전입자형 디스플레이의 상판에 magenta, yellow, cyan의 대전입자를 주입하고 하판에는 black 대전입자를 주입하고 합착하여 패널을 제작 후 각 패널에 0V에서 210V까지 10V step으로 전압을 인가하여 응답속도를 측정한 후 같은 조건의 패널에 aging전압을 인가 후 구동전압을 인가하여 응답속도를 비교하여 각 컬러에 대한 응답속도 특성변화와 개선을 연구하였다.

• Korean Chemical Engineering Research
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• 제46권3호
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• pp.545-549
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• 2008

${\gamma}-AlO$(OH) 졸 입자 뿐만 아니라 소성처리된 ${\gamma}-Al_2O_3$ 입자의 표면특성을 ${\gamma}-AlO$(OH) 졸 제조시 숙성단계에 의하여 조절하였다. 연구결과, ${\gamma}-AlO$(OH) 졸 입자의 등전점은 숙성 증가에 따라 pH 9.25에서 pH 8.70까지 감소하였으며 ${\gamma}-Al_2O_3$ 입자의 경우는 pH 9.90에서 pH 8.86까지 감소하였다. 숙성에 따른 ${\gamma}-Al_2O_3$ 입자의 산, 염기 특성을 고찰한 결과, ${\gamma}-Al_2O_3$ 입자의 산량은 숙성시간의 증가에 따라 0.1367 mmol/g에서 0.0783 mmol/g까지 감소하였으며, Hammett 산성도함수 $H_o$는 4.8 이상의 산세기를 보였다. 한편 ${\gamma}-Al_2O_3$ 입자의 염기량은 숙성시간의 증가에 따라 0.4399 mmol/g에서 0.3074 mmol/g 까지 감소하였다. 따라서 졸-겔법에 의한 ${\gamma}-Al_2O_3$ 제조시 숙성공정이 산, 염기점의 양을 포함한 표면특성을 조절할 수 있는 중요 공정변수임을 제시하였다.

• 한국식품과학회지
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• 제52권6호
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• pp.573-579
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• 2020

흑생강의 생리활성 규명을 위한 연구의 일환으로 흑생강의 제조공정을 숙성 조건에 따라 5단계로 구분하여 각 제조 단계에서 얻은 흑생강의 이화학적 특성 및 항산화 활성을 원료 생강과 비교하였다. 흑생강의 갈색도와 적색도(a값)는 숙성 기간이 경과됨에 따라 원료 생강에 비해 유의적으로 증가되는 경향이었으나, 명도(L값)와 황색도(b값)는 유의적으로 감소된 경향이었다. 총당은 숙성 2단계에서 가장 높은 함량이었으나, 숙성 3단계 이후부터는 유의적으로 감소되는 경향이었다. 흑생강에서 숙성 기간이 경과됨에 따라 gingerol 함량은 감소되었으나, 6-shogaol 함량은 17.7-34.1배 증가되었다. 총 페놀 및 플라보노이드 함량은 숙성 2단계에서 가장 높은 함량이었으며, 그 이후에는 감소되는 경향이었다. 흑생강의 라디칼 소거활성과 환원력은 각각 숙성 2단계 및 3단계에서 가장 높았으며 그 이후에는 점차 감소되는 경향이었다. 숙성단계별 흑생강의 항산화 활성은 갈색도, 6-shogaol, 총당 및 총 페놀의 함량과 높은 양(+)의 상관관계를 보여 2-3단계 숙성이 항산화 활성 증대에 효과적일 것으로 생각된다.

• International Journal of Safety
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• 제1권1호
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• pp.36-42
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• 2002

This paper is aimed at predicting the life of rubber insulating gloves under normal operating stresses from relatively rapid test performed at higher stresses. Specimens of rubber insulating gloves are subject to multiple stress conditions, i.e. combined electrical and thermal stresses. Two modes of electrical stress, step voltage stress and constant voltage stress are used in specimen aging. There are two types of test for electrical stress in this experiment: the one is Breakdown Voltage (BDV) test under step voltage stress and thermal stress and the other is lifetime test under constant voltage stress and temperature stress. The ac breakdown voltage defined as the break-down point of insulation that leakage current excesses a limit value, l0mA in this experiment, is determined. Because the very high variability of aging data requires the application of statistical model, Weibull distribution is used to represent the failure times as the straight line on Weibull probability paper. Weibull parameters are deter-mined by three statistical methods i.e. maximum likelihood method, graphical method and least squares method, which employ SAS package, Weibull probability paper and FORTRAN, respectively. Two chosen models for predicting the life under simultaneous electrical and thermal stresses are inverse power model and exponential model. And the constants of life equation for multistress aging are calculated using numerical method, such as Gauss Jordan method etc.. The completion of life equation enables to estimate the life at normal stress based on the data collected from accelerated aging test. Also the comparison of the calculated lifetimes between the inverse power model and the exponential model is carried out. And the lifetimes calculated by three statistical methods with lower voltage than test voltage are compared. The results obtained from the suggested experimental method are presented and discussed.

• 한국재료학회지
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• 제4권5호
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• pp.524-534
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• 1994

소량의 misch metal과 Zr을 함유한 CuZnAI형상기억 합금의 변태온도에 미치는 열사이클 및 기계적 성질 변화에 대하여 고찰하였다. 합금원소 첨가에 따라 결정립에 매우 미세화 되었으며 용체화 처리후 100~$350^{\circ}C$구간에서 경도값 변화를 조사하기 위하여 post quench aging과 step quench aging처리한 결과 $200^{\circ}C$와 $250^{\circ}C$에서 최고의 경도값을 나타냈다. $M_f$온도이하에서 인당시험한 결과 파단강도와 연실율은 결저립이 미세할수록 증가하는 경향을 보였다. 또한 파단강도는 as quenching처리한 경우보다 post quench aging처리한 경우에 보다더 증가하였다. $\beta$-상에서의 시효는 $M_s$온도를 강하시켰으며 마르텐사이트상에서의 시효는 $A_s$ 온도를 증가시켰다. post quench aging 에 따른 $A_s$의 변화는 $\beta$에서의 회복율에 기여하였으며 변태온도 ($A_s-M_s$)히스테리시스는 열사이클에 의하여 증가하는 경향을 보였다.

• 보건교육건강증진학회지
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• 제8권1호
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• pp.14-21
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• 1991

In accordance with the rapid industrialization in Korea, there have been remarkable changes in the health environment. The major changes are ; the change of disease structure, the aging of population structure, the diversification of health needs and the increase of health care costs. Because most of health problems stems from the environment, national health policy should be conducted according to the environmental changes. It is necessary for the voluntary organizations as well as the government ones to plan and participate the national health promotion movement on a national level so as to make the people form the attitude that health promotion is better than cure. Also, it is desirable that national health promotion movement be implemented gradually especially by four steps, 1) preparation step; 2) enlightenment step: 3) implementation step: 4) evaluation step.

• 한국의류산업학회지
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• 제11권6호
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• pp.857-866
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• 2009

The objective of this study was to design a fashion storytelling method, which is a strategic instrument for constructing a fashion show with artistry and popularity, based on the principle and structure of storytelling. In order to understand the concept and principle of storytelling composed of story and telling and to introduce storytelling into fashion shows, we associated fashion design with the substance of a story, a show with the form of telling, and a fashion show with storytelling. Based on these associations, we analyzed the relationship between fashion show and storytelling and developed basic elements and structure necessary to design a fashion storytelling method. Through this study, we designed a fashion storytelling method with five steps, which are story planning, story development, fashion show structure design, fashion show production, and fashion show execution. These steps were again classified into contents setting step, structure design step, and expression step. The contents setting step included story planning and development for creating stories, and the structure design step means the design of fashion show structure that adds telling to the stories. Lastly, the expression step included fashion show production and execution that forms a storytelling by combining the stories and the telling.

• 한국압력기기공학회 논문집
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• 제7권4호
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• pp.38-43
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• 2011

For the efficient and safe operation of nuclear power plant, evaluating quantitatively aging phenomenon of major components is necessary. Especially, typical aging parameters such as stresses and cumulative usage factors should be determined accurately to manage the lifetime of the plant facility. The 3-D finite element(FE) model is generated to calculate the aging parameters. Mechanical and thermal transfer functions called Green's functions are developed for the FE model with standard step input. The stress results estimated from transfer functions are verified by comparing with 3-D FE analyses results. Lastly, we suggest an effective fatigue evaluation methodology by using the transfer functions. The usefulness of the proposed fatigue evaluation methodology can be maximized by combining it with an on-line monitoring system.

• 대한물리의학회지
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• 제16권2호
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• pp.81-90
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• 2021

PURPOSE: Aging causes a decrease in muscle mass and a change in posture, which reduces motor function and makes it difficult to perform daily activities independently. As these factors are closely related to the deterioration of the quality of life, it is very important to prevent and manage negative changes in the musculoskeletal system. Forest healing is a nature therapy course that maintains and promotes health using various environmental factors in a forest. The purpose of this study was to identify the effects of the forest healing anti-aging programs on the physical health of the elderly. METHODS: Ten elderly people participated in this study, as part of a forest healing anti-aging program for two days. Functional fitness, muscle strength, gait function, and balance were evaluated before and after the program. RESULTS: The number of arm curls, chair stands, and steps in a 2-min walk significantly increased (p < .05). 8-feet up & go time was significantly decreased (p < .05). Biceps brachii, quadriceps femoris, and calf muscle strength were significantly increased (p < .05). Gait velocity and cadence were significantly increased (p < .05). Step length, stride length, step time, swing time, stance time, and cycle time were significantly decreased (p < .05). Reaching distance in the lateral directions was significantly increased (p < .05). CONCLUSION: The forest healing anti-aging program improves the physical health of the elderly.

• 열처리공학회지
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• 제8권4호
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• pp.333-339
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• 1995

The reduction and diffusion process(R-D process) is an economical way to produce the functional materials which contain rare-earth elements and has been applied to the production of rare-earth magnet meterials($SmCo_5$, $Nd_{15}Fe_{77}B_8$), magneto-optical(MO) target materials and hydrogen storage alloy, etc. However, because of difficult to control of the final composition, the R-D process has not been applied to production of the 2-17 type rare earth permanent magnet materials which contain several elements. Therefore, this work was as a basic study for the production of the 2-17 type rare earth permanent materials with composition $Sm(Co_{0.72}Fe_{0.21}Cu_{0.05}Zr_{0.03})_{7.9}$ by the R-D process, the following were mainy examined ; the amount of metallic calcium as a reductant, homogenization condition of the alloy after the R-D reaction, masuring of magnetic properties of the sample after step aging. The sample prepared by the R-D process contained a little more oxygen than that prepared by the melting method, however, showed almost the same magnetic properties.