• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1820-1823
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• 2003

A high speed feeding type laser cutting M/C is developed for precise cutting of sheet metal. This paper has been carried out to obtain cutting characteristics and optimal cutting conditions of the developed high speed feeding type laser cutting M/C by a design of experiments. Cutting speed. laser power. laser duty and gas pressure are control factors for the surface roughness. The major factors affecting the surface roughness and the optimum cutting conditions are studied with minimum experiments using Taguchi method.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.155-160
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• 2001

This study is performed to evaluate and design the vibration characteristics of the onboard machinery with resilient mountings. To reduce the vibration level of onboard machinery with resilient mountings, it is important to evaluate and, if necessary, modify the vibration characteristics of the resilient mountings. In this study, we have developed a program to calculate natural frequencies of the machinery with resilient mountings, forced vibration levels due to internal excitation force of the machinery itself and external excitation forces. of the main engine and the propeller. and the force and motion transmissibility of the resilient mountings. The developed program is also able to be applied to optimal design of the resilient mountings for obtaining a target natural frequency and for achieving a minimum forced vibration level at the center of gravity of the machinery.

• 한국철도학회논문집
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• 제4권3호
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• pp.110-115
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• 2001

Recently, many engineers actively participate in research and development w.r.t the weight reduction and the safety increase of vehicle body structure to meet the requirement of fuel economy and regulations. However, vehicle design concept related with weight reduction and safety increase is reduced to the design conflict problem. In the paper, the axial and bending collapse test of aluminum extruded beams are performed and the collapse characteristics are investigated. The analysis method to verify the fracture characteristics of aluminum extruded beam is presented and discussed.

• Journal of Mechanical Science and Technology
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• 제17권5호
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• pp.668-678
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• 2003

For the purpose to facilitate development of high-speed spindle units (SUs) running on rolling bearings, we have developed a beam element model, algorithms, and software for computer analysis of thermal characteristics of SUs. The thermal model incorporates a model of heat generation in rolling bearings, a model of heat transfer from bearings, and models for estimation of temperature and temperature deformations of SU elements. We have carried out experimental test and made quantitative evaluation of the effect of operation conditions on friction and thermal characteristics of the SUs of grinding and turning machines of typical structures. It is found out that the operation conditions make stronger effect on SU temperatures when rpm increases. A comparison between the results of analysis and experiment proves their good mutual correspondence and allows us to recommend application of the models and software developed for design and research of high-speed SUs running on rolling bearings.

• 한국염색가공학회지
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• 제25권2호
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• pp.140-151
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• 2013

In order to investigate the mechanical properties of working clothes materials considering industrial settings, the test weaving materials were compared with the existing materials depending on the season. The material design of the test fabrics were changed through fineness, composition, density of materials then subsequently treated with functional finish. As a result of evaluation of the forms according to KES-FB system, Koshi was deduced, and Numeri and Fukurami were increased. Thereby, the test weaving materials became flexible, surface became smoother, elasticity and volume characteristics indicated to have been improved. Consequently, the THV value of working clothes materials for test weaving was increased compared to existing materials which indicated improved result of the total hand value. Specially, the winter cloth material indicated improved drape characteristics and dimensional characteristics, showed improved liveliness as being compressed softly.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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• pp.199-209
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• 1998

Since most engineering problems have had open-ended and ill-defined characteristics, design process is in advance attended with determination of alternatives based on realistic constraints after definition of appropriate problem. And it is completed with selection of best alternative through their comparison and investigation, and with performance of selected-alternative's detail design. As the process of structural design compared with that of general design, this paper presents a paradigm which can generate structural design alternatives, select optimum structure among them and simultaneously set its optimum design variables in reference of several objective as a result in more extended design region. For this purpose, specialized genetic algorithms which can handle design alternatives and multicriteria problems is used.

• 대한간호학회지
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• 제36권6호
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• pp.1042-1054
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• 2006

Purpose: Previous evaluation studies of the visiting nursing program explained an average change of the participants' health status, without considering socio-ecological characteristics and their impacts. However, these factors must affect individual health problems and lifestyles. For effective and appropriate community based programs, the Geographical Information System(GIS) can be utilized. GIS is a computer-based tool for mapping and analyzing things that happen on earth, and integrates statistical analysis with unique visualization. The purpose of this study was to evaluate visiting nursing care and to advocate the usefulness of planning and evaluating visiting nursing programs using Exploratory Spatial Data Analysis(ESDA) with GIS technology. Methods: One hundred eighty-four elderly participants with cerebrovascular risk factors who lived in 13 areas of one community received visiting nursing care. The data analyzed characteristics of pre-post change and autocorrelation by ESDA using GIS technology. Results: Visiting nursing care showed an improvement in the participants' lifestyle habits, and family management ability and stress level, while the improvements were different depending on the regions. The change of family management ability and stress level correlated with neighborhoods (Morgan's I=0.1841, 0.1675). Conclusions: Community health providers need to consider the individual participant's health status as well as socio-ecological factors. Analysis using GIS technology will contribute to the effective monitoring, evaluation and design of a visiting nursing program.

• Journal of Advanced Research in Ocean Engineering
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• 제3권2호
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• pp.66-74
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• 2017

Since risers have to be operated without being replaced during the design life time after installation, fatigue evaluation as well as strength analysis should be performed. The fatigue life of the riser is known to be dominantly influenced by wave loading and vortex induced vibration (VIV) phenomena. The fatigue life evaluation method and the behavior characteristics of the riser by the wave have been done a lot. Even though the VIV is an important source of fatigue damage for SCR, the evaluation method and behavior characteristics by VIV have not been studied relatively. Most of the S / W for calculating VIV fatigue are a semi-empirical model based on various theoretical models and experiments. For better understanding of VIV response, it is necessary to investigate the effect of parameters which affects the analysis result. This paper summarizes the results of parametric study performed to enhance the understanding of relationship between each parameter and fatigue analysis result.

• 한국주거학회논문집
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• 제26권1호
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• pp.91-98
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• 2015

The purposes of this study are to analyze the problems of the elderly using kitchens by ergonomic work evaluation methods, and to make suggestions for planning and remodeling of the kitchens for the elderly. The work evaluation methods which used in this study were direct-observing methods, which contained the process of 2 or 3 times each visiting to four different houses where elderly people live. For direct-observing methods, analyzing with movement observations and observation methods with photos and videos were used. Characteristics of subject elderly people and problems of their kitchens were analyzed by static measurements, interviews, pictures, and videos. The data, which are recorded movements of the preparing meal of the elderly were analyzed by playing it back repeatedly. As results, physical characteristics of the elderly was the most important consideration; a participant with the arthritical knee was limping at the kitchen entrance due to the difference of the floor level, and a user with a bent back was working on the floor or place an elbow on the worktable to support her body. Those results made a conclusion about the common problems of the kitchens, and suggested the check list which has to be considered when designing the elderly using kitchen.

• 상하수도학회지
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• 제22권6호
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• pp.647-655
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• 2008

Sewer Rehabilitation Project (SRP) is planed, designed and constructed to perform its intended performance as sewerage delivery systems. Recently, a subject of performance evaluation methodology development for SRP has become a great deal of concern among researchers in Korea. From the view point of Sewage Treatment Plant (STP), however, the estimation of improvement efficiency for SRP is in lack of reliability due to the fact that affections for the treatment efficiency and operating condition are not reflected on SRP design and construction. In this study, statistical methodology was used in the analysis of data, which are taken during 1,186 days ($1^{st}$ Jan. 2005 - $31^{th}$ Mar. 2008) from the influent, effluent and operating conditions of full-scale STP($25,000m^3/d$). Then the effect of SRP on the influent characteristics and operating conditions changing was compared and evaluated. Results from the statistical evaluation show that SRP causes characteristic changes in influent and exerts a significant effect especially on the performance of STP.