• Journal of the Korean Wood Science and Technology
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• 제42권5호
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• pp.563-570
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• 2014

Two transversely isotropic plasticity-based models for wood, derived from the standard compression properties and the embedment properties were investigated for suitability of application for bolted connections. It was found that the conventional connection models involving the compression properties were incapable of simulating the real behaviour of the connections because the compression properties provided too stiff foundation to represent embedding behaviour of wood under the bolt. However, wood foundation-based connection model that was newly developed using the bolt embedment properties showed good agreement with the actual behaviour of bolted connections.

• 한국해양공학회지
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• 제16권1호
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• pp.46-51
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• 2002

Fatigue life estimation by the theoretical stress concentration factors are, in general, considerably different from test results. And in calculating stress concentration factor, it is very difficult to consider actual geometry and material property which are the notch shapes, imperfections or defects of materials such as porosities inclusions and casting defects, etc. Therefore, the paper deals with the experimental method to find out the more exact stress concentration factors by measuring the strain distributions on each specimen by 3D-ESPI(Electronic Speckle Pattern Interferometry) System. Then the fatigue lives are compared between theoretical calculations using stress concentration factors determined by 3D-ESPI system and fatigue test results.

• 가정과삶의질연구
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• 제3권1호
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• pp.51-67
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• 1985

The purpose of the present paper is to review the content of the Consumer Education Programs, is to establish a hypothetical model regarding the contents of the consumer Education programs, and is also to analyze the contents of the Consumer Education Programs seen from the various angles of the value of our home life. For this, we have researched literatures and habe made the hypothetical model for the desirable contents of the consumer education programs, and also have conducted a case study together with and analysis bearing the actual evidence. Form what we have studied regarding the results of the research, conclusions that can be derived are as follows; First, the contents of the consumer education programs of Korea are not sufficient to improve the quality of the environments of our houses, family life, and decision making. Secondly, the contents of the consumer education do not meet the societal and economic changes. Third, since the contents of the consumer program of Korea emphasize the theory-oriented discussion, they are not suitable to educate the consumers who are really in need of consumer education.

• 경영과학
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• 제19권1호
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• pp.179-188
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• 2002

Ventures through technological innovation are increasingly suggested as one of the main engines for economic growth that can help control inflation and black trade balance. The Purpose of this study is to extract the network performance factors for ventures according to ventures life cycle. For the Purpose, the existing studies were examined into start-up company, entrepreneurial firm, smell firms with competitive advantage against large firms, and ventures network activity. And 63 samples from ventures in Korea were taken and analyzed empirically. The analyses and results are (1) the actual conditions of network activity on ventures; (2) the investigation of relationship between network activity and performance of ventures by venture's life cycle through the observations of Korean ventures. From the results, It Is also found that factors such as external environment and a ventures life cycle have been considered as the main influences on the performance of ventures. In addition, limitations and suggestions for further studies are noted.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.132-138
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• 2000

Complex gear shifting and high speed-reduction ratio reduce the transmission efficiency in power driveline of agricultural tractors. According to a field test, the power transmission efficiency of a tractor in transporting operations was estimated about 70%. However, the actual efficiency was found by the experiment to fluctuate in a range of 56 to 87%. Therefore, the constant efficiency model commonly used for a simulation of power drivelines is not likely to simulate its performance more accurately. In order to predict power transmission efficiency more accurately, a new model was proposed and the new concepts of the maximum efficiency and sticking torque were introduced. The error mean between the measured and the predicted efficiencies was about 2.3% in mean. The new model reflecting the transmission characteristics in the power driveline of tractors could be used to analyze and predict the power transmission performance of tractors more accurately.

• Journal of Welding and Joining
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• 제31권3호
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• pp.49-53
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• 2013

Recently, studies about application of magnesium alloy sheet to automotive bodies are on the increase. For application to automotive bodies, researches about characteristics of resistance spot welding of magnesium alloy sheet are essential. Electrode life of resistance spot welding of magnesium alloy is very short due to sticking of magnesium alloy to copper alloy electrode. To increase electrode life, most effective method is inserting cover plate between electrode and magnesium sheet. But application of cover plate to actual process is difficult and decreases welding productivity. Process tape supplied automatically as cover plate can minimize lose of productivity and increase welding quality. In this study, resistance spot welding of magnesium alloy is carried out with applying process tape. Acceptable welding current region according to electrode force and welding time is determined.

• 한국농공학회지
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• 제45권2호
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• pp.35-44
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• 2003

A system reliability method is proposed to decide reliable serviceability of agricultural irrigation system. Even though reliability method is applied to real engineering situations involving actual life environments and maintaining costs, a number of Issues arise as a modeling and analysis level. This article use concepts that can be described the probability of failure with time variant and series-parallel system reliability analysis model. A proposed method use survivor function that can simulate a time-variant performance function for a lifetime before it is required essential maintenance or replacement to define a target probability of failure in agricultural irrigation canal. In the further study, it is required a relationship between a state of probability of failure and current serviceability to make the optimum repair strategy to maintain appropriate serviceability of an irrigation system.

• 한국재료학회지
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• 제25권10호
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• pp.516-522
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• 2015

Aging aircraft structures are inevitably exposed to environment for a long time facing many potential problems, including corrosion and wide spread fatigue damage, which in turn cause the degradation of flight safety. In this study, the environmental surface damages on aging aircraft structures induced during service were quantitatively analyzed. Additionally, S-N fatigue tests were performed with center hole specimens extracted from aging aircraft structures. From the results of quantitative analyses of the surface damages and fatigue tests, it is concluded that corrosion pits initiated during service reduce the fatigue life significantly. Finally, using the fracture mechanics and the EIFS (equivalent initial flaw size) concepts, the remaining fatigue life was predicted based on actual fatigue test results.

• 지역사회간호학회지
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• 제29권2호
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• pp.194-205
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• 2018

Purpose: The aim of this study is to investigate and elucidate actual experiences of alcoholics' spouses using familial social gatherings. Methods: A total of nine women whose alcoholic husbands were attending Al-Anon meetings held in Y Cathedral in S District of Seoul were included in this study. Data collection of this study was conducted through in-depth interviews with participants from September 24 to November 30, 2015. Data analysis was conducted at the same time as the data collection, and analysis was performed according to the method suggested by Colaizzi(1978). Results: We categorized the participants' experiences into five themes including 'Trapped in a Deep Dark Tunnel', 'Life of Walking in an Endless Tunnel', 'Reaching a Dead End', 'Walking towards a Ray of Light', 'Finding Oneself on a Strange Path'. Conclusion: The results of this study provide an understanding of the essential structure of the life experiences of alcoholic spouses using familial social gatherings.

• 한국정밀공학회지
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• 제10권3호
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• pp.69-80
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• 1993

It is important to prevent roll failure in hot rolling process for reducing maintenance coat and production loss. Roll material and rolling conditions such as the roll force and torque have been intensively investigated to overcome the roll failures. In this study, a computer roll life prediction system under working condition is developed and evaluated on IBM-PC level. The system is composed and fatigue estimation models which are stress analysis, crack propagation, wear and fatigue estimation. Roll damage can be predicted by calculating the stress anplification, crack depth propagation and fatigue level in the roll using this computer model. The developed system is applied to a work roll in actual hot rolling process for reliability evaluation. Roll failures can be diagnosed and the propriety of current working condition can be determined through roll life prediction simulation.