• 한국생산제조학회지
• /
• 제21권3호
• /
• pp.387-393
• /
• 2012

It is very difficult to determine suitable cutting conditions in order to obtain accurate cutting profiles because machining errors caused by tool deflection depend upon cutting conditions. In this study the relationship between real cutting profiles (inclined shapes and machining errors) and cutting conditions was modeled in order to fabricate draft angle on micro molds. CCD (Central Composite Design) of DOE (Design Of Experiment) and RSM (Response Surface Method) were applied in order to model the relationship between cutting conditions and machining errors. In order to use CCD the range of radial depth of cut was chosen by $10-90{\mu}m$ and the range of feedrate was chosen by 200-300mm/min, and 9 points of cutting conditions were chosen inside determined ranges. Then, actual cutting processes were carried out as respect to 9 points of cutting conditions, draft angles and real cutting profiles were measured on cutting profiles, each response surface function was determined by conducting response surface analysis and the functions were represented by 3-dimensional graphs, contour lines and $101{\times}101$ matrices. Consequently it is possible to determine suitable cutting conditions in order to obtain arbitrary given draft angles and cutting profiles by using modeling. To validate proposed approach in this study suitable cutting conditions were determined by modeling in order to obtain arbitrary given draft angle and cutting profile, and actual cutting processes were carried out. About 95% of good agreement between predicted and measured values was obtained.

• 보건행정학회지
• /
• 제9권1호
• /
• pp.201-233
• /
• 1999

This study was carried out to find out the factors affecting on organizational commitment of hospital employees. For the purpose, the questionnaire-based research was done with 1280 hospital employees who were working in 2 university hospitals and 4 general hospitals located in Taegu City and Kyungpook Province from November 20, 1997 to December 22, 1997. The results of the study were summarized as follows. There were significant correlations among environmental variables, psychological variables, structural variables, vertical conflict, horizontal conflict, job satisfaction, and organizational commitment. By path analysis, variables such as pay, work involvement, work definiteness, met expectations, positive affectivity, distributive justice, job security, expectations before entering a hospital had significant positive effect on job satisfaction in order of size, while, vertical conflict, job opportunity, and horizontal conflict had significant positive effect on job satisfaction in order of size, while, vertical conflict, job opportunity, and horizontal conflict had signifecant negative effect in order of size. Variables such as job satisfaction, job security, work involvement, pay, vertical conflict, met expectations, distributive justice, positive affectivity, work unit control, job autonomy, and job routinization had significant positive direct effect on organizational commitment in order of size, while, job opportunity, job hazards and resource inadequacy had significant negative direct effects in order of size. It was found that the following variables, listed in order of size, had significant total effects on organizational commitment : job satisfaction, job security, job opportunity, work involvement, pay, met expectations, distributive justice, positive affectivity, job hazards, and work unit control. In considering abovc findings, it is recommended that programs for job satisfaction promotion, job security, decrease of intent to leave, work involvement promotion, adequate pay, met expectations, distributive justice, positive affectivity promotion, job hazards decrease, and work unit control grant should be implemented to increase organizational commitment.

• 한국식생활문화학회지
• /
• 제19권3호
• /
• pp.336-347
• /
• 2004

This study was conducted to investigate eating-out behavior patterns of youths, especially junior high and senior high school students. 1600 questionnaire surveys were distributed and 1487 were used for analysis. In order to consider regional differences as well as overall characteristics of youths' eating-out behaviors, the subjects were evenly sampled from north Seoul, south Seoul, big cities, middle/small cities and small towns. As for the frequency of eating-out, 62.7% of respondents answered once to twice per week. For the can of more than 5 times of eating-out per week, the respondents from south Seoul showed the highest frequency. For the case of no eating-out, the highest frequency was shown from the small towns. As for the most frequently visited place for eating-out, 33.6% of respondents answered Korean style restaurants, and 17.6% Boon-sik(Sanck-bar). Regarding the preference of Korean style restaurants, the highest rate was shown from the residents of big cities. For the question of when they eat out, 89.6% answered dinner and 6.3% lunch. For the question about reason of choosing particular restaurants, 61.5% of respondents referred to tastes and 16.6% price. For the question of the most important reason of eating out, 52.6% point out 'meal solution' and 25.6% 'for meeting.' As for the people accompanied when eating out, 67.2% of the respondents answered family. For the cost of eating out per person, 45.7% of the respondents spent 2000-4000 won for lunch; 31.1% spent 5000-10,000 won for dinner; 33.7% of the respondents spent more than 20,000 won for the special events. Regarding the regional differences of eating-out cost, respondents from south Seoul tended to spend the biggest amount of money for lunch, dinner and special day.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1996년도 추계학술대회 논문집
• /
• pp.41-45
• /
• 1996

In order to realize the high-speed machining, the relative technologies for high speed machining tool and high speed machining are required now, The machining accuracy is influenced on the disturbance by the synchronized working conditions(cutting force, spindle Run-out, thermal deformation etc.) In this paper, the effect of spindle Run-out for the high speed machining is investigated. The results show that the spindle Run-out has a great influence on the machining accuracy in high speed machining.

• 복식
• /
• 제65권5호
• /
• pp.74-87
• /
• 2015

It is common for popular products to sell out, and be out of stock. The purpose of this study is to examine the responses of consumers who have experiences of shopping online, and finding their desired products unavailable from being sold out. In order to carry out the study, in-depth interviews were conducted with ten recruits who were recruited from the Internet community, Soul Dresser, which is part of the Korean web portal, Daum. First, the cognitive reaction of the interviewees showed both positive and negative responses when they found out that their desired product was sold out. However, in the case of emotional reaction, all of them showed negative reactions. Observations showed that consumers researched and found similar products including price when they realized that their desired products were not going to be re-stocked. And in cases of similar products not being available, the consumers looked to buy other types of products such as bags, shoes, and other accessories.

• Geomechanics and Engineering
• /
• 제37권4호
• /
• pp.323-339
• /
• 2024

If the pressure exerted on the face of a tunnel excavated by TBM exceeds a threshold, it leads to failure of the soil or rock masses ahead of the tunnel face, which results in heaving the ground surface. In the current research, the upper bound method of limit analysis was employed to calculate the blow-out pressure of tunnels excavated in rock masses obeying the Hoek-Brown nonlinear criterion. The results of the proposed method were compared with three-dimensional finite element models, as well as the available methods in the literature. The results show that when σ_ci, m_i, and GSI increase, the blow-out pressure increases as well. By doubling the tunnel diameter, the blow-out pressure reduces up to 54.6%. Also, by doubling the height of the tunnel cover and the surcharge pressure exerted on the ground surface above the tunnel, the blow-out pressure increased up to 74.9% and 5.4%, respectively. With 35% increase in the unit weight of the rock mass surrounding the tunnel, the blow-out pressure increases in the range of 14.8% to 19.6%. The results of the present study were provided in simple design graphs that can easily be used in practical applications in order to obtain the blow-out pressure.

• 한국문헌정보학회지
• /
• 제38권1호
• /
• pp.51-75
• /
• 2004

본 연구의 목적은 공공도서관의 운영 활성화에 기여하기 위하여 현행 공공도서관의 민간 위탁의 성과를 분석하는 것이다. 성과의 분석 대상으로는 민간 위탁을 실시하고 있는 3개 공공도서관을 선정하여, 문헌연구, 설문 및 방문조사를 수행하였다. 주요한 고찰사항은 첫째. 공공도서관 민간위탁의 필요성과 배경 및 현황의 검토, 둘째, 민간위탁의 찬$\cdot$반 양론 및 쟁점의 정리, 셋째, 민간위탁의 현행 성과 분석을 포함하였고, 마지막으로 분석에 근거하여 향후 바람직한 공공도서관 민간 위탁 제도 도입과 운영 전략을 제시하고 있다.

• 한국식생활문화학회지
• /
• 제15권5호
• /
• pp.325-337
• /
• 2000

The purpose of this study was to investigate several aspects of eating out behavior especially in relation to food waste. The data were collected from 620 housewives in Jeonbuk area but, except for 134 case not eating out . The 66.9% of subjects ate eating out 1 to 2 times monthly. The younger in age, higher in education level and employed housewives, higher in monthly income have a more increase in eating out frequency. In the 50.8% of subjects food rest was rare when eating out. The higher in educational level and higher in monthly income have an inclination to more food waste. The 51.4% of subjects don't know [Good Menu System]. We housewives should order a planned and moderate food amount when eating out, and make an effort normally anywhere for the reduction of food waste, and then the wasted food and food rubbish will be reduced. Besides this, the restaurants should practice [Food Bank] & [Good Menu System] and the academic world should make further researches on this field. Moreover the government administration should enlighten the people and have a public information for the more reasonable food culture.

• International Journal of Automotive Technology
• /
• 제1권1호
• /
• pp.35-41
• /
• 2000

The crashworthiness of vehicles with finite element methods depends on the geometry modeling and the material properties. The vehicle body structures are generally composed of various members such as frames, stamped panels and deep-drawn parts from sheet metals. In order to ensure the impact characteristics of auto-body structures, the dynamic behavior of sheet metals must be examined to provide the appropriate constitutive relation. In this paper, high strain-rate tensile tests have been carried out with a tension type split Hopkinson bar apparatus specially designed for sheet metals. Experimental results from both static and dynamic tests with the tension split Hopkinson bar apparatus are interpolated to construct the Johnson-Cook and a modified Johnson-Cook equation as the constitutive relation, that should be applied to simulation of the dynamic behavior of auto-body structures. Simulation of auto-body structures has been carried out with an elasto-plastic finite element method with explicit time integration. The stress integration scheme with the plastic predictor-elastic corrector method is adopted in order to accurately keep track of the stress-strain relation for the rate-dependent model accurately. The crashworthiness of the structure with quasi-static constitutive relation is compared to the one with the rate-dependent constitutive model. Numerical simulation has been carried out for frontal frames and a hood of an automobile. Deformed shapes and the Impact energy absorption of the structure are investigated with the variation of the strain rate.

• 한국환경과학회지
• /
• 제23권10호
• /
• pp.1663-1671
• /
• 2014

The object of this research is to find out the psychological change of observer according to the index of Greenness in the space of scenic planting, and research is proceeded with total 112, male students 69, and female students 43. The index of Greenness experimented with 5 pictures, 20%, 40%, 60%, 80%, and 100%, and carried out the test after selecting each picture of the index of Greenness for landscaping in Konkuk University Global Campus. To find out the mood condition of testee, POMS and SD was used for analyzing. As a result of TMD among POMS, male and female students are shown as each 60% > 100% > 40% > 20% > 80% in order. As a result of SD, male and female students are shown as 80% > 20% > 40% > 60% > 100% in order and the index of Greenness 100% makes people feel fluent and natural about plants but closed and constrained than the index of Greenness 80%.