• 한국정밀공학회지
• /
• 제23권5호
• /
• pp.137-142
• /
• 2006

The muffler which reduce the exhaust noise and vibration from engine influence on the engine performance. Recently, exhaust variable valve has set up in the muffler controls the backpressure in the exhaust system. And the backpressure variation according to the exhaust variable valve opening has developed the engine performance. First, the preceding of structural analysis is needed and simulation experiment is requested for the study on the design factor to influence on the operation of the exhaust variable valve. In this study, setting up the various variables according to each composition element needed for the structural analysis of the exhaust variable valve, it is experimented the analysis on the influence of each design factor with the calculation of stress distribution and the displacement to cause about the backpressure for the valve through parameter study.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
• /
• pp.1320-1326
• /
• 2011

The maximum speed of high-speed rail is restricted to various factors such as track condition including slope and radius, tunnel and dynamic stability of vehicle. Among the various factors, traction effort and resistance to motion is principal and basic factor. In addition, at high speed over 300km/h, aerodynamic drag amounts up to 80% of resistance to motion, that it can be said that aerodynamic drag is the most important factor to decide the maximum speed of high-speed rail system. This paper deals with a measure to increase the maximum speed of high-speed train by reducing aerodynamic drag. The traction effort curve and resistance to motion curve of existing high-speed train under development has been employed to set up the target of aerodynamic drag reduction to reach up to 500km/h without modification traction system. In addition, the contribution of various sources of aerodynamic drag to total value has been analyzed and the strategy for implementation of aerodynamic drag reduction has been discussed based on the aerodynamic simulation results around the train using computational fluid dynamics.

• 한국농공학회논문집
• /
• 제63권3호
• /
• pp.27-33
• /
• 2021

Reclaimed land was mainly used as agricultural land for rice production. As a higher value-added business in the agriculture has recently been activated, green houses are being constructed. In case of green house construction on the reclaimed land, it is generally soft ground with high soil water content, so it is important to design the foundation for greenhouse construction. The object of this study, a pull-out test was conducted to derive the base line data of the wooden pile foundation when constructing a green house. To reproduce the actual site, 30% of soil saturation and 70% of soil saturation were created in the soil box. Groove number and depth were set as design factors of the wooden pile, and a pull-out test was conducted. As a result of the test, pull resistance increased as the number of grooves increased, pull-out resistance according to groove depth was different according to soil saturation. Also, after the experiment, we want to compare the set-up effects over time.

• 디자인학연구
• /
• 제16권3호
• /
• pp.81-90
• /
• 2003

본 연구의 목적은 인간의 본질인 신체적ㆍ정신적 특성에 따른 제품의 새로운 분류 방식을 제시하고 이를 통해 제품의 미래를 이해하는데 있다. 연구의 목적을 위해 인간과 제품의 관계 특성을 과거와 미래를 통해 비교 분석하였고, 이 과정에서 제품을 발생학적으로 분류할 수 있었다. 연구는 그 결과를 '신체적 제품'의 미래와 '정신적 제품'의 미래로 나타냈다.

• Journal of Mechanical Science and Technology
• /
• 제15권9호
• /
• pp.1217-1225
• /
• 2001

The governing equations are derived for the analysis of a stepped labyrinth gas seal generally used in high performance compressors, gas turbines, and steam turbines. The bulk-flow is assumed for a single cavity control volume set up in a stepped labyrinth cavity and the flow is assumed to be completely turbulent in the circumferential direction. The Moodys wall-friction-factor model is used for the calculation of wall shear stresses in the single cavity control volume. For the reaction force developed by the stepped labyrinth gas seal, linearized zeroth-order and first-order perturbation equations are developed for small motion about a centered position. Integration of the resultant first-order pressure distribution along and around the seal defines the rotordynamic coefficients of the stepped labyrinth gas seal. The resulting leakage and rotordynamic characteristics of the stepped labyrinth gas seal are presented and compared with Scharrers theoretical analysis using Blasius wall-friction-factor model. The present analysis shows a good qualitative agreement of leakage characteristics with Scharrers analysis, but underpredicts by about 20%. For the rotordynamic coefficients, the present analysis generally yields smaller predictied values compared with Scharrers analysis.

• 경영과정보연구
• /
• 제15권
• /
• pp.147-164
• /
• 2004

The purpose of this paper is on employees as internal customers and the critical role this group plays in the delivery of quality results. The set up of research model for verification was as follows. The research model was drawn as internal service quality level $\Rightarrow$ internal customer satisfaction $\Rightarrow$ enterprise outcome. Then, two hypotheses were established to the research model. Through the factor analysis and multiple regression analysis, the results are as follows. First, internal service quality level turned out to be affected indirectly through internal customers' satisfaction rather than a direct factor to affect the enterprise outcome. Second, internal customers' satisfaction was proved to be the most important factor for the enterprise outcome as ti was the intimate factor precedent to the enterprise outcome. However, there could be a variation of response according to the personal circumstances of respondents since the respondents were from different enterprises and consisted various job positions and age group. Namely it included a limitation of rather unaccurate resulting values because the transverse methods were performed for convenience though it needed a longitudinal research to accomplish the general purpose of this study.

• 한국생활과학회지
• /
• 제18권2호
• /
• pp.419-429
• /
• 2009

The purpose of this study was to research the preference for the entertainers image and imitation behavior. The research was a survey and the subjects were 1,034 middle and high school students. The collected data was analyzed using frequency, statistics analysis, t-test, crosstab, ANOVA, factor analysis and multiple regression analysis. Result were as follows; The preference for the entertainment, most of the adolescents loved the singer and the TV talent. The feminine and urban image was their favorite image for the entertainer. The favorite image was significantly different according to the gender and age. Star entertainer imitation behaviors showed the differences according as adolescent's gender and age. The unique marketing strategy is required as the job in the entertainment business, so the tend to follow up and imitate all attractive factors and favorite image of the entertainer. This study was for helping the adolescent who are very sensitive and going to set up their identification to get the role model as the fair way to be the social member, helping the one to set up the image-making way for each entertainment's job, and helping the enterprise who want to use the image of the star in their promotion.

• 한국콘텐츠학회논문지
• /
• 제12권12호
• /
• pp.761-770
• /
• 2012

본 연구는 선행연구를 확장하여 백화점의 물리적 환경, 감정반응 및 행동의도 간의 관계를 중심으로 연구모형을 수립하고, 이들 변수들 간의 관계에 대해 한국과 중국 소비자 비교분석을 통하여 국가별 차이를 규명하는데 주된 목적을 두었다. 실증분석을 위해 한국과 중국의 백화점 이용고객을 대상으로 설문조사를 실시하였고, 총 659부의 설문을 최종 분석에 활용 하였다. 실증분석 결과 첫째, 점포의 물리적 환경은 감정반응과 부분적으로 유의한 관계가 있는 것으로 나타났다. 물리적 환경 차원 중 디자인요인, 사회요인은 긍정적 감정에 정(+)의 영향을 미치며, 긍정적 감정을 경유하여 행동의도에 간접적으로 영향을 미치는 것으로 분석되었다. 사회요인은 부정적 감정에 부(-)의 영향을 미치며, 부정적 감정을 경유하여 행동의도에 유의한 영향을 미치는 것으로 분석되었다. 둘째, 한국과 중국 소비자 간의 차이가 검증되었다. 한국 소비자의 경우 물리적 환경요인 중 주변요인이 긍정적 감정에 영향을 미치지 않는 것으로 나타났다. 반면 중국 소비자는 디자인요인과 사회요인이 긍정적 감정에 유의한 영향을 미치지 않는 것으로 분석되었다. 본 연구의 결과는 이론적인 측면은 물론 실무적인 측면에서도 중국을 중심으로 한 해외 진출 소매유통기업의 마케팅 전략 수립에 활용할 수 있는 유익한 시사점을 제공해 줄 수 있을 것이다.

• Nuclear Engineering and Technology
• /
• 제54권6호
• /
• pp.2188-2197
• /
• 2022

To ensure the safety margin of a reactor pressure vessel (RPV) under normal operating conditions, it is regulated through the pressure-temperature (P-T) limit curve. The stress intensity factor (SIF) obtained by the internal pressure and thermal load should be obtained through crack analysis of the nozzle corner crack in advance to generate the P-T limit curve for the nozzle. In the ASME code Section XI, Appendix G, the SIF via the internal pressure for the nozzle corner crack is expressed as a function of the cooling or heating rate, and the wall thickness, however, the SIF via the thermal load is presented as a polynomial format based on the stress linearization analysis results. Inevitably, the SIF can only be obtained through finite element (FE) analysis. In this paper, simple prediction equations of the SIF via the thermal load under, cool-down and heat-up conditions are presented. For the Korean standard nuclear power plant, three geometric variables were set and 72 cases of RPV models were made, and then the heat transfer analysis and thermal stress analysis were performed sequentially. Based on the FE results, simple engineering solutions predicting the value of thermal SIF under cool-down and heat-up conditions are suggested.

• 한국콘텐츠학회논문지
• /
• 제12권11호
• /
• pp.313-337
• /
• 2012

본 연구는 최근 들어서 전시회가 활성화됨에 따라 각 전시회는 참관객에게 많은 관심과 만족도를 높이기 위하여 온갖 심혈을 기울이고 있다. 이에 전시회의 물리적 환경과 체험 등에 관한 선행연구들을 바탕으로 연구모형을 도출하고 가설을 설정하였다. 본 연구모형에서 체험의 제공수단으로 물리적 환경이 체험요소에 어떠한 영향을 미치는지를 분석하고, 체험요소가 참관객의 만족도에 어떠한 영향을 미치는지 본 연구에서 규명하여 참관객들의 방문을 증가시키기 위한 체험 요소를 확인하고 참관객의 만족을 높이는 방안을 참가업체에게 유용한 정보를 제공하고자 한다. 전시회의 물리적 환경(접근성, 매력성, 청결성, 편리성, 쾌적성, 인적 서비스)을 독립변수로 설정하였고, 체험(감각적, 감성적, 인지적, 행동적, 관계적 체험)을 매개변수로 하여 참관객의 만족도를 규명하였다. 이를 종합하면 전시회의 물리적 환경은 체험에 영향을 미치며, 체험은 참관객의 만족도에 영향을 미치는 것으로 나타났다. 따라서 전시 주최자들은 전시회를 개최하는데 있어서 각각의 물리적 환경과 체험요소를 충분히 검토하여 참관객의 만족도를 높여야 할 것이다.