• 한국구조물진단유지관리공학회 논문집
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• 제13권3호통권55호
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• pp.164-172
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• 2009

현수교는 주케이블이 목표하는 형상을 이루어 기하학적 강성을 갖도록 앵커, 새들과 같은 장치를 적용하고 있다. 지금까지의 연구에서는 두 장치를 모두 고정절점으로 단순화하여 해석하는 것이 일반적이었다. 그러나 새들의 경우 주케이블의 슬라이딩 현상이 발생할 수 있으며 이로 인하여 구조물의 응답이 달라진다. 특히 현수교의 시공단계 초기에 셋백로프를 철거하거나 셋백을 수행하지 않는 경우 새들 전후 주케이블의 장력 차이가 커지므로 슬라이딩이 발생하기 쉽다. 따라서 본 연구는 유한요소법을 이용한 케이블의 슬라이딩 해석방법을 제시하고 슬라이딩을 고려한 현수교의 시공단계별 해석을 수행하여 슬라이딩을 고려하지 않은 해석결과와 차이를 분석하였다. 슬라이딩을 고려한 해석을 통해 얻어진 결과는 구조물에 불리한 응답을 나타낼 수 있으므로 주케이블과 새들 사이의 슬라이딩을 고려한 해석은 필수적이다. 또한 본 연구의 슬라이딩 해석방법 및 해석결과는 이후 현수교의 설계와 시공시의 참고자료로 활용될 수 있다.

• 한국정밀공학회지
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• 제6권4호
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• pp.136-144
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• 1989

This paper presents the vibrational characteristics of linear damped vibrational systems with a linear dynamic absorber. The amplitude ratios of main vibrational system are derived from the equation of motion for the system, and optimal natural frequency ratio and damping ratio of dynamic absorber are obtained by computer simu- lation, which minimize the amplitude ratio of main vibrational system for the whole range of the frequency ratio. And, the effects of the parameters on the amplitude ratios are investigated. As the results, the effect of the natural frequency ratio on the amplitude ratio of main vibrational system is more important than that of the damping ratio of dynamic absorber as damping ratio of main vibrational system becomes larger. For the case of large damping ration of main vibrational system becomes larger. For the case of large damping ratio of main vibration system, the amplitude ratios are not decreased dramationally in spite of inoreasing mass ratio.

• 한국기계가공학회지
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• 제15권4호
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• pp.134-140
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• 2016

Main Spindle System has effect on performance of machine tools and working quality as well as is required of high reliability. Especially, it takes great importance in producing automobiles which includes a large number of working processes. However, main spindle unit in Machine tools are often cases where damage occurs do not meet the design life due to driving in harsh environments. This is when excessive maintenance and repair of machine tools or for damage stability has resulted in huge economic losses. Therefore, this studying propose a method of accelerated life test for diagnosing and prognosis the state of life assessment main spindle system. Time status monitoring of diagnostic data - through the analysis of the frequency band signals were carried out inside the main spindle bearing condition monitoring and fault diagnosis.

• Nuclear Engineering and Technology
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• 제32권1호
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• pp.67-76
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• 2000

Significant wall thinning due to flow accelerated corrosion(FAC）was recently reported in main feedwater pipes in 3 Korean pressurized water reactor(PWR) plants. The main feedwater pipes in one plant were repaired using overlay weld method at the outside of pipe, while those in 2 other plants were replaced with new pipes. In this study, the effect of the wall thinning in the main feedwater pipes on piping integrity was evaluated using finite element method. Especially, the effects of both the overlay weld repair and the stress concentration in notch-type thinned area on the piping integrity were investigated. The results are as follows : (1) The piping load carrying capacity may significantly decrease due to FAC. In special, the load carrying capacity of the main feedwater pipe was reduced by about 40% during about 140 months operation in Korean PWR plants. (2) By performing overlay weld repair at the outside of pipe, the piping load carrying capacity can increase and the stress concentration level in the thinned area can be reduced.

• 한국의류학회지
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• 제37권4호
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• pp.467-481
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• 2013

The study examined the main effect of the reward channel and reward time of customer loyalty programs for on-offline shopping channels; in addition, it investigated the interaction effect of the reward channels and merchandise as well as the interaction effect of the reward time and merchandise. An online apparel shopping web experiment was conducted with a 2 (reward channel: online channel reward vs. offline channel reward) ${\times}2$ (reward time: immediate vs. delayed) ${\times}2$ (merchandise: online channel product vs. offline channel products) between-subject factorial design. An online shopping channel was considered the core-shopping channel and a department store was considered the cross-shopping channel. Loyalty program value, core-channel loyalty and cross-channel loyalty were measured as dependent variables. A total of 845 shoppers (who had experiences in shopping in both channels) participated in the experiment. The results of the study revealed (1) the main effect of the reward channel on loyalty program value, core-channel loyalty and cross-channel loyalty [online>offline channel rewards], (2) the main effect of reward time on loyalty program value, core-channel loyalty and cross-channel loyalty [immediate>delayed reward], and (3) the interaction effect of the reward channel and merchandise on loyalty program value, core-channel loyalty, and cross-channel loyalty. (4) Finally the study found that loyalty program value affected cross-channel loyalty indirectly through core-channel loyalty. This study suggested diverse theoretical and managerial implications for multi-channel retailers.

• 한국사회복지학
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• 제37권
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• pp.241-269
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• 1999

본 연구는 사회적 지지가 실직자의 심리사회적 안녕감에 갖는 영향을 탐구함으로서 사회적 지지이론에 대한 경험적 분석과 실직자를 위한 사회복지서비스 전략개발을 목적으로 수행되었다. 충청북도, 충주시 및 인근지역에 거주하는 369명의 실직자를 대상으로 설문조사를 실시, 사회적 지지가 실직자의 심리사회적 상태에 미치는 주효과(main effect)가설과 스트레스 완충효과(stress buffering effect)가설을 탐구하였다. 연구결과는 사회적 지지의 주효과가설과 스트레스 완충효과가설의 부분적인 검증을 시사하였다. 사회적 지지의 주효과에 대한 검증에서는 가족으로부터의 지지가 표본 실직자들에게 가장 유용한 사회적 지지의 출처였고 실직자의 심리사회적 안녕감에 가장 긍정적인 영향을 주는 요인으로 밝혀졌다. 또 사회적 지지의 스트레스완충효과가설이 검증이 된 경우에도 완충효과는 그다지 크지 않았던 것으로 분석되었다. 본 연구결과를 바탕으로 사회적 지지의 이론 검증을 위한 추후연구방향이 제시되었고 실직자를 위한 사회복지서비스 개발전략에 대한 시사점이 제기되었다.

• 한국컴퓨터정보학회논문지
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• 제20권5호
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• pp.91-98
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• 2015

본 연구는 국내 중-대형 SW개발 프로젝트 현장에 적용되고 있는 PMS의 주요 기능 및 적용효과에 대하여 소개하고, PMS적용의 중요성과 개선 필요성을 제시하고자 한다. PMS는 CMMI, PMBOK와 같은 글로벌 모델이 권고하는 모범 사례를 기반으로 주요 기능이 구현되었으며, 각 시스템이 목표로 하는 산업분야와 시스템을 구성하는 솔루션에 종속된 특화기능을 보유하고 있다. PMS적용에 따른 효과는 정성적, 정량적 효과로 구분할 수 있다. 대표적인 정성적 효과로는 SW개발 기업의 이미지 및 경쟁력 향상이며, 아울러 대표적인 정량적 효과로는 프로젝트 수행 현장의 관리 노력 절감에 따른 재무적 효과이다. 소프트웨어 프로젝트 수행과 관련한 법적, 환경적 변화에 따라 PMS적용에 대한 고객의 요구에 따른 수요는 증가될 것이므로 프로젝트 관리 분야의 글로벌한 변화추세에 따른 지속적 개선이 요구된다.

• 수산해양교육연구
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• 제24권4호
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• pp.494-506
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• 2012

The purpose of this study was to analyse 3, 4, 5-year-old children's private speech according to their age and task characteristics (structured task vs. unstructured task). In order to achieve the goal, the main effect of age, characteristic of tasks and interaction effect were considered among age and characteristic of tasks on preschool children's private speech. The subjects were each 30 3, 4, 5-year-olds from preschool in Busan, South Korea. The structured task was puzzle task and the unstructured task was drawing task from TCT-DP. The data was analyzed by repeated measurement two way ANOVA: 3(age) ${\times}$ 2((characteristic of task). As a result, firstly, total private speech of 4-year-old was higher than 3-year-old, 5-year-old in both tasks, and total private speech of 5-year-old was higher than 3-year-old in both tasks. Secondly, the task-irrelevant private speech was not affected by main effect of age and characteristic of task and interaction effect between age and characteristic of task. Thirdly, the task-relevant private speech was received both main effects and interaction effects between age and characteristic of task. Finally, the external manifestation of inner speech were not received effect of age but received effect of characteristic of task, and received interaction effect between age and characteristic of task. The results of this study imply that characteristic of task is an important factor inducing children's private speech.

• 한국정밀공학회지
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• 제25권8호
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• pp.72-79
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• 2008

To meet demand of big capacity and high speed rotation for washing machine, more stress from bending and twisting are complexly loaded onto the shaft supporting the horizontal drum, causing problems in fracture strength and fatigue life. Shafting system is mainly divided into flange and shaft. Shaft and flange connected by inserting shaft serration into flange on the process of die casting. When the system is operating, the gap is formed between serration and flange. But, Serration has various design factors and the optimal values can't be easily determined. Using a design of experiment (DOE) based on the FEM (Finite Element Method), this study was performed investigating the interaction effect between the various design factors as well as the main effect of the each design factor under bending, twist and vibration and proposed optimum design using box-behnken method among response surface derived from regression equation of simulation-based DOE.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1511-1516
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• 2007

Because Seaming process of MPJ (Mechanical Press Joining) has various design factors such as thickness, bending radius, seaming width, caulking press width and the dynamic factor such as multistage plastic working, elastic recovery, residual stress, the optimum conditions can't be easily determined. Using a design of experiment based on the FEM, which has several advantages such as less computing, high accuracy performance and usefulness, this study was performed investigating the interaction effect between the various design factor as well as the main effect of the each design factor during drum MPJ and proposed optimum condition using center composition method among response surface derived from regression equation of simulation-based DOE.