• 한국자동차공학회논문집
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• 제11권1호
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• pp.42-48
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• 2003

LPG has been a broad concern of pro-environmental alternative fuel for vehicles. Recently, the new Liquid Phase LPG Injection(LPLI) system extends the limit of power of LPG engine and gives a chance to substitute LPG engine for diesel engine of heavy duty vehicles that are the main resources of air pollution in urban area. Large bore size of heavy duty LPG engine derives a serious knock problem. To find an optimal MBT conditions, it is necessary to know how the flame develops in the combustion chamber and find where the knock positions are. In this study. the ion-probe head gasket was used to estimate the knock position. Inverse operation of the ion-probe signal provides the flame developing characteristics. The further the position is from the spark plug, the later the flame arrives and the more times knock occurs. The main factor that effects knock position is inferred a flor situation of mixed gas in the combustion chamber.

• 전력전자학회논문지
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• 제18권2호
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• pp.123-130
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• 2013

This paper proposes the switched trans Z-source inverter(STZSI) which combined the characteristics of the trans Z-source inverter(TZSI) and the switched inductor Z-source inverter(SLZSI). The proposed STZSI has the same performance compared with the SLZSI which is improved the voltage boost performance of the conventional typical X-shaped ZSI, and it has advantage that circuit structure of Z-impedance network is more simple. And, in order to step up the voltage boost factor under the condition of the same duty ratio, unlike the SLZSI adding the inductors and diodes, the proposed method is dune by changing the turn ratio of trans primary winding of Z-impedance network. To confirm the validity of the proposed method, PSIM simulation and a DSP(TMS320F28335) based experiment were performed using trans with turn ratio 1 and 2 under the condition of the input DC voltage VI=50V, duty ratio D=0.1 and D=0.15. As a result, under the same input/ouput condition, the inverter arm voltage stress of the proposed method is reduced to about 15%-22% as compared with typical X-shaped ZSI, and the elements in Z-impedance network of the proposed method is reduced as compared with the SLZSI.

• 대한지역사회영양학회지
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• 제10권4호
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• pp.546-554
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• 2005

The purpose of this study was to identify the relationship between the levels of foodservice management activities and job satisfaction of the dietitians in elementary schools. Out of 130 questionnaires distributed to elementary school dietitians in Incheon, 127 were returned and analyzed ($98\%$ response rate). The questionnaire included two multiple-item scales for measuring foodservice management activities and job satisfaction, respectively. All the items in the scales were coded 1 to 5 for 'certainly no', 'no', 'neutral', 'yes', and 'certainly yes' and grouped by using factor analyses. Most of the responding dietitians were working for schools in urban areas and have independently managed on-site kitchens. The 19 items on food service management activities were grouped into 6 factors and the mean scores of the levels of Personnel Hygiene Management, Education & Training, Sanitation & Safety Management, Menu Quality Management, Service Management, and Environment Management were 4.76, 4.26, 4.24,4. 05, 3.61 and 3.39, respectively. The 23 items on job satisfaction were grouped into 4 factors and the mean scores of the satisfaction levels of Systematic Environment, Job Duty, Job Condition, and Physical Environment were 3.38, 2.83, 2.53, and 2.08, respectively. Overall, the levels of food service management activities and job satisfaction were positively associated with a correlation coefficient of 0.254 (p > 0.01). In particular, satisfaction levels on job duty itself and systematic environment were positively associated with the levels of overall management activities. The results suggest that improving dietitians' job satisfaction could increase the levels of management activities of school foodservice dietitians, resulting in quality improvement of school food service.

• 한국보건간호학회지
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• 제14권2호
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• pp.446-463
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• 2000

The purpose of this study is to identify the recent attitude of nurses toward euthanasia. and to provide necessary basic information for on-the-job-training and student education. The subject of this study are 521 nurses working in the hospital attached to university in Seoul. to whom I distributed questionnaires which were made on the basis of the instrument of Tordella & Neutens. from 21. July. 2000 to 27. July. 2000. The collected data were statistically examined through SPSS program and were analysed through Frequency. Means. Factor Analysis. T-test. and ANOVA. The study results are as follows: 1. General characteristics of nurses are in age of average 26.9. in education of junior college graduate $83.7\%$. in both parent alive $85.2\%$. in marital status of single $77.5\%$. in religion of christianity $34.8\%$ against non-religion 38.3%. The term of employment is average 52.7 months and are in various post. The experience of family dying $46.3\%$ and of terminal care $56.8\%\;and\;82.5\%$ are information oriented to euthanasia. 2. The attitude toward euthanasia reveals 3.40 score in average. and is significant in relation to religion among general characteristics (p<.000). 3. Passive euthanasia reveals 2.48 score in average with significance in religion(p<.000), and duty post (p<.046). Natural euthanasia is 4.09 score which is in most characteristics positive direction with significance in information oriented group. Indirect euthanasia reveals 2.98 score and are significant in various group of age (p<.004). both parents alive (p<.005), marital status (p<.000). term of employment (p<.022), duty post (p<.005), and family dying(p<.028). Family commitment is 3.51 score with significance in both parents alive (p<.023) and term of employment (p<.020). Clear definition of euthanasia and analysis of its effects need to be studied in order to improve proper courses of nursing patients with terminal illness.

• 한국조리학회지
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• 제6권1호
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• pp.225-252
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• 2000

This study aims to examine theoretical frame work of franchise restaurant, the characteristics of store manager's job and the level of their job satisfaction through an empirical investigation. Job satisfaction survey study shows that store managers consider important all work to be attended to as part of their duty with service management on top. It is also found that the majority of store managers consider their aptitude as most important job satisfaction factor and those, who are satisfied with their job content, advancement and the prospect, are more proactive in delivering qualify service and more than willing to commit themselves to their duties. Regrading demographical variables, store managers with scholarly competence and higher pay level are more likely to be satisfied with their job but married men are not satisfied with the work environment in general. Ergo, Businesses should correspond by capitalizing on those store managers content with their duty thus collecting additional information and providing opportunities to further contribute to the business. For those dissatisfied individuals, however, businesses should determine their demands and by educational training supply a motive therefore making possible the conversion of such individuals to satisfied store managers and their active participation in business management. But, as with any study, this one has a number of limitation which constraints the generalizability of the empirical findings. It has not been for long since franchise restaurants established in domestic market and has been few studies regarding this topic there. Furthermore, managers are not willing to release operation related data. Therefore, further study are urged to overcome this limitation and should examine other dimensions of job satisfaction such as relations between revenue and profit with the level of store manager's job satisfaction remain to be investigated.

• 한국식생활문화학회지
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• 제24권6호
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• pp.728-738
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• 2009

The purpose of this study was to evaluate job stress factors of school food service nutritionists according to the number of years they have worked. The subjects of this survey included 125 nutritionists (69 from full-time employees and 56 from part-time nutritionists) from elementary school, middle school, and high school in the Gangwon area. The results showed that stress related to duty was the top job stress factor, followed by environment-related stress, personal stress, organization-related stress and stress caused by human relations. In terms of the degree of stress, part-time nutritionists have more stress compared to full-time nutritionists. This was especially true for nutritionists that had been employed for one year. In this case, the degree of stress was much higher than long time employed nutritionists. In terms of how to deal with job stress, school nutritionists eliminated stress directly (with direct countermeasures). In order to deal with stress, workers expected stable employment such as pay (wages), promotions, etc. In particular, part-time school nutritionists had stronger expectations. When correlation between job stress factors were examined, environment-related, duty-related, organization-related, human relations-related and personal stress were all shown to be mutually related.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2907-2912
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• 2007

The cooling water system for the PEFP 20 MeV proton accelerator was established and tested to obtain the precise resonance frequency of DTL through the temperature control of cooling water. The water temperature in the main flow loop was manipulated by adjusting the proportion of hot water returning from the DTL structures through the heat exchanger loop. Due to low duty factor operation and insufficient cooling loop installation of the DTL tanks, the manual mode operation was applied to maintain the DTL temperatures close to their resonance temperatures. The optimized process conditions with flow balancing and pressure drop in the DTL cooling systems are reported.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.315-316
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• 2002

Electrochemical discharge machining is a very recent technique for non-conducting materials such as ceramics and glasses. ECDM is conducted in the NaOH solution and the cathode electrode is separated from the solution by $H_2$ gas bubble. Then the discharge is appeared and the non-conductive material is removed by spark and some chemical reactions. In the ECDM technology, the $H_2$ bubble control is the most important factor to stabilize the discharging condition. In this paper, we proposed the discharge peak monitoring/ discharging duty feedback algorithms for the discharge stabilization and the feasibility of this algorithm is verified by various pattern machining in the constant preload conditions for the cathode electrode.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.509-514
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• 2004

This paper introduces the modified slip energy recovery system in order to improve its power factor and to reduce harmonics of line current waveforms. Twelve pulse line commutated converter with the chopper type IGBT is applied where the chopper is applied across the DC terminal and the chopped DC is fed to the converter operating as an inverter and then passed through the wye-wye and delta-wye transformer circuit. This scheme leads to be able to adjust the speed of the motor by the duty cycle of the chopper operating in PWM mode. The fuzzy logic controller is also introduced to the modified slip energy recovery system for keeping the motor speed to be constant when the load varies. The experimental results in testing the 0.22 kW wound rotor induction motor from no-load condition to rated condition show the effectiveness of the proposed control scheme.

• 교육녹색환경연구
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• 제9권3호
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• pp.59-67
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• 2010

Architectural design for school can be completed well when the environment-friendly elements are satisfied. In other words, the environment-freindly element could be most important idea for school planning, and one should have this direction for each element as a design goal. In this study, I defined the "environment-friendly" as the environment for nature and human. I examined what could satisfy those and would be its principles. I set up the criteria to satisfy each priciple. Most important factor to keep the relation between nature and human would be reducing carbon dioxide emissions, and a green belt would absorb it. Therefore, I think that there would be effective possibility when suitable conditions are applied in phases. Every school can have comfort as environment-friendly facility, at the same time, contribute to nature. Also, students can learn and study nature, and perform a duty as human.