• Title/Summary/Keyword: second order effects

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Selection Factors for Outdoor Sporting Goods in Seoul (도시민의 야외 운동장소 선택요인 분석)

  • Lee, Yeun-Sook;Lee, Dong-Joo;Ahn, Chang-Houn;Gu, Na-Eun
    • KIEAE Journal
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    • v.11 no.2
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    • pp.17-25
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    • 2011
  • In order to provide basic data for designing the outdoor exercise environment to promote the health of the citizens, this study has analyzed the status of citizens' use of outdoor exercise places that have been supplied extensively recently and the factors affecting the citizens' choice of the places. A survey was made on 20 spots in 12 places where outdoor exercise equipment is installed to identify the characteristics of use and the factors affecting the selection of the spots and for the 1,733 survey sheets collected finally SPSS program was used to analyze the multiple answers. Major results of this research are as follows: First, since light exercise equipment mostly for bodily exercises has been installed, it has brought practical effects for the physically weak people, aged people and the people who scarcely exercise, while decreasing the users' economic burdens. Second, the scales of important factors the users think in selecting their exercise spots were 'spaciousness (2,028 times)' > 'accessibility (1,751 times)' > 'fitness (1,583' > 'supportability (1,445)' > 'community centeredness (1,260).' Third, the ratios of important factors regarding the choice of environment of outdoor exercise were 'near to walk (16.1%)' > 'nice natural environment (12.3%)' > 'always free to exercise (9.7%)' > 'shortage of exercise equipment (7.4%)' > 'possible to accompany family/neighbors (6.7%)' > 'no economic burden (6.5%).

Electrical and Structural Design of Air-conditioning Fan Motor for Noise Reduction

  • Han Hyung-Suk;Mo Jin-Yong;Kim Chang-Hyun;Lee Jae-Kwon;Jeong Weui-Bong
    • Journal of Mechanical Science and Technology
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    • v.20 no.10
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    • pp.1653-1661
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    • 2006
  • AC induction motors have been widely used for fan motor of the air conditioner indoor unit. Noise of these AC induction motors is usually caused by the coupling effects of structural and electrical systems. The rotating torque and the noise from AC induction motor were discussed in this paper,. First, the modification of motor was carried out in order to reduce the unbalance magneto motive force between main and sub winding. Second, structural modification based on normal mode analysis and modal testing was carried out so that the fan motor does not have the natural frequencies near the 2f-line frequency. Numerical modifications through these two processes were verified by experiments, which showed that the sound pressure level at 2f-line frequency of the modified system became about 25dB less than that of conventional one.

The Influence of Information Technology Competence on Entrepreneurial Attitude and Entrepreneurial Intention (정보기술역량과 창업태도 및 창업의도의 관계에 관한 연구)

  • Choi, Dae-Soo;Sung, Chang-Soo
    • Journal of Information Technology Services
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    • v.16 no.1
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    • pp.27-39
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    • 2017
  • Lately, there is a worldwide boom for start-ups. This trends has led to develop many policies for entrepreneurship in Korea, which focused on college education. Also, as the forth industrial revolution knows no borders, demands of software early education are expanding in line with strong interests in IT (Information Technology). Information technology is now an essential competency for all professionals who need creative thinking. And entrepreneurs are a representative job that requires creative thinking. This study suggests IT competencies-IT planning competencies (ITPC) and IT development competencies (ITDC)-as a core factor of the entrepreneurial intention. This paper is to study the relationship between IT competencies and entrepreneurial Intention. So we investigated IT competence and entrepreneurial intention in university students with a questionnaire. The results of this empirical study can be summarized as follows. First, IT planning competencies have positive influence on entrepreneurial attitude and intention. But IT development competencies do not influence directly on entrepreneurial intention. Second, entrepreneurial attitude have mediating effects in the relationship between IT planning competencies and entrepreneurial intention. So, we need to develop good contents related to the IT planning capabilities when organizing training programs in start-up course. In order to improve the quality of entrepreneurship education, it will be necessary to develop educational contents that can have a broad perspective for understanding the trends of technology convergence and creating opportunities.

Numerical Analysis of Nonlinear Effect of Wave on Refraction and Diffraction (파의 굴절 및 회절에 미치는 비선형 효과에 대한 수치해석)

  • 이정규;이종인
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.2 no.1
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    • pp.51-57
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    • 1990
  • Based on second-order Stokes wave and parabolic approximation, a refraction-diffraction model for linear and nonlinear waves is developed. With the assumption that the water depth is slowly varying, the model equation describes the forward scattered wavefield. The parabolic approximation equations account for the combined effects of refraction and diffraction, while the influences of bottom friction, current and wind have been neglected. The model is tested against laboratory experiments for the case of submerged circular shoal, when both refraction and diffraction are equally significant. Based on Boussinesq equations, the parabolic approximation eq. is applied to the propagation of shallow water waves. In the case without currents, the forward diffraction of Cnoidal waves by a straight breakwater is studied numerically. The formation of stem waves along the breakwater and the relation between the stem waves and the incident wave characteristics are discussed. Numerical experiments are carried out using different bottom slopes and different angles of incidence.

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A Study on Sensibility Ergonomics Approach to Bathroom Design (감성공학기법을 적용한 욕실디자인에 관한 연구)

  • Lee, Han-Seok;Jung, Hyun-Won;Oh, Young-Keun;Jung, A-Young;Kim, Jung-Wook
    • Korean Institute of Interior Design Journal
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    • v.18 no.6
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    • pp.69-76
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    • 2009
  • As sensibility ergonomics are broadly spread, recently in interior design area, interests on roles of sensibility, sensibility effects for users, and etc has been increased. As a study on sensibility design for interior design area, the study applied sensibility ergonomics technique to bathroom interior design. Sensibility ergonomics technique is integrated into each phase of bathroom design process in order to produce 4 design alternatives. Sensibility evaluation on design alternatives was performed for subject of designers, and analyzed the results to show the relationship between sensibility of designers and design factors and to identify characteristics of designer's sensibility structure. The results of the study are as follows. First, it's found that in the bathroom interior design of sustainable concept, uses of bright colors with white tone and floor tile creates positive sensibility responses such as delight, healthiness, spaciousness, and cheerfulness. Second, designers' sensibility structure about sustainable bathroom is composed of three axles, healthiness, eco-friendliness, and refinement. Third, designers think colors of interior and finished materials is most important, and window, artificial lighting, layout, and space size related to those is important too. The process and approach in the study might contribute to building a fundamental of sensibility design research in interior design area.

Effect of Post Surface Modifications on Tribological Properties of Electrodeposited Ni/Ni-SiC coatings

  • Gyawali, Gobinda;Joshi, Bhupendra;Tripathi, Khagendra;Lee, Soo Wohn
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.05a
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    • pp.43-44
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    • 2015
  • Electrodeposited Ni and Ni-SiC composite coatings were prepared on Cu substrates by using the Ni-Sulfamate electrolytic bath. Thus prepared samples were subjected for the two different types of post surface modification techniques; i.e. Laser Surface Texturing (LST) and Ultrasonic Nano Surface Modification (UNSM), respectively in order to investigate their effects on surface and interface related properties of the coatings. Hemispherical dimples, with 80 to 200 um dimple spacing, were created and examined on the surfaces of the materials studied. The results revealed that micro-surface texturing with 150 um dimple spacing considerably improved the coefficient of friction. Dimple spacing accuracy and incorporated second phase ceramic particles both contributed significantly to reduction in coefficient of friction. On the other hand, application of UNSM considerably modified the surface topography, led to increase the Vickers microhardness, and reduced the wear and coefficient of friction as compared to non UNSM treated Ni and Ni-SiC samples.

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Fabrication of High Tc Superconducting Nano Powder Using Chemical Process (화학공정을 이용한 초전도 나노 분말 활성)

  • Lee, Sang-Heon;Kim, Chan-Jung;Jang, Kun-Ik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.547-548
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    • 2006
  • In order to realize the commercial application of HTSC materials, it is necessary to develop the fabrication process of high Tc oxide superconductor materials with desired shape and for practical application and high critical current density as well as good mechanical strength which can withstand high lorenz force generated at high magnetic field. Much studies have been concentrated to develop the fabrication technique for high critical current density but still there are a lot of gap which should be overcome for large scale application of HTSC materials at liquid nitrogen temperature. Recently some new fabrication techniques have been developed for YBaCuO bulk superconductor with high mechanical strength and critical current density. In this project, the establishment of fabrication condition and additive effects of second elements were examined so as to improve the related properties to the practical use of YBaCuO superconductor, and we reported the production of the YBaCuO high Tc superconductor by the pyrolysis method.

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FMEA Measures for Service Failure Management (서비스 실패 관리를 위한 FMEA 이용 방안)

  • Kim, Hyun Jung;An, Qin Rui;Kim, Soo Wook
    • Journal of Korean Society for Quality Management
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    • v.42 no.1
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    • pp.43-61
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    • 2014
  • Purpose: This study identifies preventive measures for VOC management by analyzing the causes and effects of factors that contribute to high risk service failure using FMEA on KORAIL VOC data. Methods: Two research methods were used. First, a Risk Priority Number (RPN) was assigned to each KORAIL VOC based on Failure Mode and Effect Analysis (FMEA). Second, multiple regression analysis was run with RPN factors that include severity, occurrence, and detection as the independent variables and customer dissatisfaction as the dependent variable. Results: Multiple regression analysis showed that RPN factors including severity, occurrence, and detection had significantly positive relationship with customer dissatisfaction. Based on these results, an FMEA was performed on VOC categories with high RPN for railroad stations including platform, ticketing, ticket verification, parking, and escalator, and VOC categories with high RPN for trains including entrance doors, cafes, air quality, announcement, and ticket verification. Conclusion: This study has practical implications to service failure management. A priority order using FMEA was established for the list of customer dissatisfactions that should be addressed to actively manage service failure, and strategies for tackling this priority list are offered.

Effect of 2nd Anodization on the Pore Formation for Alumina Nano Templates (알루미나 나노템플레이트의 기공형성에 미치는 2차 양극산화의 영향)

  • Cho, S.H.;Oh, H.J.;Joo, E.K.;Yoo, C.W.;Chi, C.S.
    • Korean Journal of Materials Research
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    • v.12 no.7
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    • pp.533-539
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    • 2002
  • Porous anodic aluminum oxide layer for nano templates was prepared in acidic solutions. In order to investigate effects of 2nd anodization on ordered formation behaviors of the porous oxide layers, electrochemical and microstructural studies were performed, primarily using TEM, FE- SEM, AFM, and Ultramicrotomy. The pore diameter of the anodic oxide layer increased approximately linearly with increasing voltages, and to the contrary, the pore density decreased. It was shown that 2nd anodizing on the cell base after dissolving 1st anodic oxide layer was remarkably effective for forming ordered array of the pores, comparing with the case for 1st anodization only. And for controlling the diameter of pores, widening method by chemical dissolution seemed more practical than by electrochemical methods.

Experimental studies of energy savings and economic effects by direct removal of carbon dioxide in the multi-use facility ($CO_2$ 직접 제거를 통한 다중이용시설의 에너지 절감 및 경제적 효과에 대한 실험적 연구)

  • Kim, Yo Seop;Lee, Ju-Yeol;Choi, Jin Sik;Shin, Jae Ran;Lim, Yun Hui;Park, Byung Hyun;Kim, Yoon-Shin
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.3
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    • pp.466-471
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    • 2014
  • It is important to develop the smart ventilation system in order to minimize a building energy consumption using ventilation. In this study, We evaluated the efficiency of the smart ventilation system being developed at the nursery. To evaluate the energy savings and carbon dioxide removal efficiency, two kinds of experimental conditions were compared. First, air conditioner and Smart HVAC system were operated. Second, air conditioner was operating and external air was put into the inside by rate of air circulation. It was more effective when working with air conditioning and ventilation system at the same time. If the Smart HVAC system is applied in a multi-use facility, indoor air quality will be comfortable and the social cost will be reduced.