• 한국정밀공학회지
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• 제16권6호
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• pp.100-107
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• 1999

This paper describes a probabilistic remaining life assessment program for the creep crack growth. The probabilistic life assessment program is developed to increase the reliability of life assessment. The probabilistic life assessment involves some uncertainties, such as, initial crack size, material properties, and loading condition, and a triangle distribution function is used for random variable generation. The resulting information provides the engineer with an assessment of the probability of structural failure as a function of operating time given the uncertainties in the input data. This study forms basis of the probabilistic life assessment technique and will be extended to other damage mechanisms.

• 대한기계학회논문집A
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• 제24권5호
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• pp.1331-1342
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• 2000

In power generation systems a variety of structural components typically operate at high temperature and pressure. Therefore a life assessment methodology accounting for gradual creep fracture is increasingly needed for these components. The most critical defects in such structure are generally found in the form of semi-elliptical surface cracks in the welded tubular joints. Therefore the analysis of a semi-elliptical surface crack in a plate or a shell is an important problem in engineering fracture mechanics. On this background, via shell/line-spring finite element analyses of such surface cracks in the welded T and L joints under various loadings, we investigate J-integral along the crack front We first develop T and L joints auto mesh generation program providing ABAQUS input file composed of shell/line-spring finite elements. We then further develop a T and L joints life assessment program based on the experimental creep crack growth law and auto mesh generation program in a graphical user interface format Finally the remaining life of T and L joints for various analytical parameters are assessed using the developed life assessment program.

• 대한가정학회지
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• 제46권2호
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• pp.39-50
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• 2008

The purpose of this study is to constitute the background theory and framework for developing the family-empowering program of Healthy Family-Support Center(HFSC). For this purpose, first, this study emphasizes that the development of integrated and differentiated program for HFSC is needed. Second, this study shows the theoretical background including ecological system theory, family system analysis theory, and family life coaching process. Third, assessment and evaluation system and subsystems are suggested as a basic frame for developing family life diagnosis tool. This system is based on the comparative analysis about the studies relating family life planning and case management. Fourth, the process of family empowering program is suggested to accomplish the family needs and goals. This process include the assessment, family life coaching for problem solving and/or family life planning, and following education and counselling. Last, this study shows how this program is related to other programs of HFSC. Family members can participate various programs of this center for preventing or solving the problem on the basis of evaluation results. Family-empowering program for making family healthy can be a representative and integrating program for this center.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2008년도 춘계학술발표대회 논문집
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• pp.393-398
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• 2008

The environment is the important resource to use as well as to conserve for the development. Since 1990s, it has accentuated the importance of the environment and tried to conserve the environment in many areas. Among many area, the building industry has played a role to destruct the environment for providing the living decent space and brought the environmental affect. Therefore, the building industry should endeavor to mitigate the environmental affect. In building life cycle, it consumes the energy and natural resources. But it is difficult to evaluate the environmental affect during the whole building life. It is impossible to calculate the environmental affect without the much time and effort. Therefore. it requires the easy and handing program to calculate the affect to environment in each building life cycle. Until now, many program for assessing the affect to the environment have been developed and limitedly used because of the assessment scope and contents. In this paper, it aimed at developing the assessment program of LCA, focused on the energy consumption and carbon-dioxide emission compared with the domestic and foreign concerned programs. The developed program is divided into 3 areas; construction, maintenance, demolition.

• 대한기계학회논문집A
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• 제25권5호
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• pp.823-833
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• 2001

In recent years, the subject of remaining life assessment has drawn considerable attention in chemical plants, where various structural components typically operate at high temperature an pressure. Thus a life prediction methodology accounting for high temperature creep fracture is increasingly needed for the components. Critical defects in such structures are generally found in the form of semi-elliptical surface crack, and the analysis of which is consequently an important problem in engineering fracture mechanics. On this background, we first develop an auto mesh generation program for detailed 3-D finite element analyses of axial and circumferential semi-elliptical surface cracks in a piping system. A high temperature creep fracture parameter C-integral is obtained from the finite element analyses of generated 3-D models. Post crack growth module is further appended here to calculate the amount of crack growth. Finally the remaining lives of surface cracked pipes for various analytical parameters are assessed using the developed life assessment program.

• 한국안전학회지
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• 제14권2호
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• pp.11-18
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• 1999

Proper fatigue life prediction procedures are needed for mechanical structures which requires high durability and reliability. In this paper, a fatigue life prediction procedure has been developed for predicting fatigue life of moving structure under variable loadings. The developed procedure was efficiently applied for a fatigue life calculation of a container crane. Especially, the procedure is useful for safety assessment by computer simulation. A computer program was developed for fatigue life assessment by adopting the forementioned procedure.

• 한국군사과학기술학회지
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• 제21권1호
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• pp.124-132
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• 2018

This paper presents a shelf life assessment for K-1 military gas masks in the Republic of Korea using test data of Chemical Materiels Stockpile Reliability Program(CSRP). For the shelf life assessment, over 2,500 samples between 2006 and 2015 were collected from field tests and analyzed to estimate a probability of proper and improper functionality using Bayesian estimation. For this, three stages were considered; a pre-processing, a processing and an assessment. In the pre-processing, major components which directly influence the shelf life of the mask were statistically analyzed and selected by applying principal component analysis from all test components. In the processing, with the major components chosen in the previous stage, both proper and improper probability of gas masks were computed by applying Bayesian estimation. In the assessment, the probability model of the mask shelf life was analyzed with respect to storage periods between 0 and 29 years resulting in between 66.1 % and 100 % performances in accuracy, sensitivity, positive predictive value, and negative predictive value.

• Journal of Advanced Marine Engineering and Technology
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• 제25권5호
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• pp.1058-1064
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• 2001

In this paper, the development of probability distribution estimation program for fatigue crack growth lives was summarize. The probability distribution estimation program of life was developed to increase the reliability of life estimation. In this study, it is considered that the cause of scatter in fatigue crack growth data is due to material inhomogeneity. The material resistance to fatigue crack growth is modelled as a spatial stochastic process, which varies randomly along the crack path. We developed the GUI program to estimate the probability distribution and reliability using the non-Gaussian stochastic process method. This program can be used for the reliability assessment.

• 한국엔터테인먼트산업학회논문지
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• 제15권3호
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• pp.279-287
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• 2021

연구목적은 독거노인들의 인지프로그램 참여에 따른 인지기능과 건강관련 살의 질의 변화를 분석하는 데 있다. 연구대상은 독거노인 35명이며, 8주간 인지프로그램에 규칙적으로 참여하였다. 인지기능에 대한 평가로 Loewenstein occupational therapy cognitive assessment battery-Geriatic population(LOTCA-G)를 활용하여 지남력, 시지각, 공간지각, 운동실행, 시각운동 조직력, 사고조직력, 집중력을 평가하였다. 건강관련 삶의 질은 Short form-8 health survey(SF-8)를 활용하여 전반적 건강상태를 포함하여 신체기능과 역할, 통증, 활력, 사회기능, 정신건강과 정서역할을 평가하였다. 분석결과 인지프로그램 참여에 따른 인지기능과 건강관련 삶의 질이 통계적으로 유의미하게 향상되었다. 독거노인들의 인지기능과 건강관련 삶의 질을 향상시키기 위해서 인지프로그램의 참여를 고려해야 할 것이다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.369-374
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• 2004

Web-based analysis programs for reliability assessment of machine tools were developed in this study. First, the reliability data analysis program was developed to search for failure rate using failure data and reliability test data of mechanical part. Second, failure mode analysis was developed through performance tests like circular movement test vibration test for machine tools. This analysis program shows correlation between failure mode and performance test result. Third, tool life was predicted by correlation between flank wear and cutting time, using the extended Taylor tool life equation in turning data and the equivalently converted equation in order to apply ball endmill data to Taylor tool life equation in milling data. All the information related to input and result data can be stored in theses programs.