• Journal of agricultural medicine and community health
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• v.29 no.1
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• pp.91-100
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• 2004

Objectives: This study was conducted to compare the present community health practitioners(CHPs)'s operating activities with their activity in 1989. Methods: Data were obtained two hundred seventy eight CHPs by self-administered questionnaire regarding duty traits, job satisfaction, and others. Results: The number of CHPs was 255 in 1989 and 224 in 2000. Age of CHPs in 2000 was much higher than that in 1989, and married women was 64.9% in 1989 and 95.9% in 2000. Both the primary duty of CHPs in 1989 and that in 2000 was medical service, and others(maternal health, infant health, family planning, and tuberculosis management, etc) are decreased in 2000, and community health service was added to duty of CHPs in 2000. 55% of CHPs in 1989 satisfied with their job, whereas about 80% of CHPs in 2000 satisfied with their job. The CHPs perceived that their primary necessary duty among requisite duty are medical practice(57.7%), health education(31.4%), and community health service(10.9%), in contrast, unnecessary duty are family planning(68.8%), tuberculosis management(11.1%), infant health(6.3%) maternal health(5.6%). Conclusions: These results suggest that there are such alteration of job satisfaction, needs and obstacles in duty traits of CHFs. These trend of duty traits are major issues to be caught for the health service in primary health post.

• Journal of IKEEE
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• v.16 no.2
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• pp.86-94
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• 2012

Synchronization MAC Protocol such as S-MAC and T-MAC utilize duty cycling technique which peroidically operate wake-up and sleep state for reducing energy consumption. But synchronization MAC showed low energy efficiency because of additional control packets. For better energy consumption, Asychronization MAC protocols are suggested. For example, B-MAC, and X-MAC protocol adopt Low Power Listening (LPL) technique with CSMA algorithm. All nodes in these protocols joining a network with independent duty cycle schedules without additional synchronization control packets. For this reason, asynchronous MAC protocol improve energy efficiency. In this study, a low-power MAC protocol which is based on X-MAC protocol for wireless sensor network is proposed for better energy efficiency. For this protocol, we suggest preamble numbering, and virtual-synchronization technique between sender and receive node. Using TelosB mote for evaluate energy efficiency.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04a
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• pp.139-142
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• 2000

Influence of frequency and duty ratio on electro-optical characteristics are experimentally investigated in surface AC plasma display panels(AC-PDPs) by using the VDS(Versitile Driving Simulator)., in which electrode gap and width are 100 ${\mu}m$ and 260 ${\mu}m$, respectively. The filling gas is Ne-Xe gas mixture, and total pressure 400 Torr. It is found that the response time gets to be fast from 450 ns to 150 ns as pulse-off time of the sustain pulse decreases from 2 ${\mu}s$ to 0.2 ${\mu}s$. Also it is found that the IR(Infra Red) intensity and the luminous decreases as pulse-off time of the sustain pulse increases from 0.2 ${\mu}s$ to 2 ${\mu}s$.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1697-1699
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• 2001

In this paper, the circuit of AC Choppers for $CO_2$ laser power supply are proposed and investigated. IGBT-controlled ac voltage regulators, operating at high frequency chopping mode. Chopping-to-supply duty ratio plays an important role in terms of laser output. Laser input energy is varied by controlling the leakage transformer used with the proposed system. This improved circuit employs a 3 electrode - type and Ring Blower. This improved circuit system has many advantages compared with the conventional SMPS such as simple design requirement, easy implementation, high reliability, low switching loss, and consequently high efficiency. As a result, the maximun output was 16W at duty-ratio of 92%, total gas mixture of $CO_2$ : $N_2$ : He = 1 : 9 : 15, total pressure of 15torr.

• Culinary science and hospitality research
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• v.13 no.2
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• pp.69-80
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• 2007

The purpose of this study is that problems caused by labor environment of cuisiniers in hotels need to be considered and studies regarding a part-time cuisinier in a special-grade hotel need to be conducted. This study analyzes the influence of labor conditions and organizational commitment of a part-time hotel cuisinier on duty satisfaction. It consists of two parts: a research based on the review of the literature and empirical study methods. The method of human resource management in hotels such as treatment of a part-time cuisinier in a special-grade hotel and the way of management as a result of an empirical study are proposed. First, as a result of conducting research on duty satisfaction to part-time cuisinier, most of them are highly satisfied with their duty regardless of their age and academic backgrounds. Second, men hold a majority; woman staffs tent to have a had time working overtime considering the situation that hotels run for 24 hours. That is the main reason why less woman staffs work in hotels than man staffs do. Part-time staffs would like to work consistently after they get upgraded to a regular worker. Forth, it is considered to break down into detailed sectors and speciality is highly demanded.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.10 s.352
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• pp.97-103
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• 2006

This paper presents the method of improving second order intermodulation distortion(IMD2) and dc-offset problems in down-conversion mixer. A simple analysis reveals the IMD2 and dc-offset can be eliminated by controlling the duty cycles of local oscillator(LO) inputs. A mixer with the proposed method has been simulated with a $0.13{\mu}m$ RF CMOS technology with 5% mismatch in the load resistance, the mixer shows 2.04dBm IIP2 and 22mnV input referred DC-offset. By controlling two duty cycles of LO inputs, IIP2 and DC-offset can be improved to 38.8dBm and $777{\mu}V$, respectively.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.5
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• pp.22-33
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• 2000

Since the heavy-duty power manipulator generally has high ratio gear reducers at its joints, its dynamic characteristics is much slower than that of the master manipulator and it is likely to encounter the saturation in the input magnitude when it is used as the slave manipulator in telemanipulation systems. This paper proposes a force reflecting and compliant control scheme for the heavy-duty power telemanipulator. The main advantage of the proposed scheme is that it provides a precise position and compliant control performance for a telemanipulator with control input saturation. The stability of the proposed scheme is analyzed and a series of experiments shows its performance.

• Environmental and Resource Economics Review
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• v.33 no.1
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• pp.33-57
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• 2024

This study analyzes the purchase subsidy for electric light-duty vehicles in terms of environmental benefits and total cost of ownership(TCO). For the environmental benefits, we considered the emissions from the power generation mix and reflected the change in efficiency of electric vehicles according to the temperature distribution. The environmental benefits of driving electric vehicles were estimated to be between KRW 2.2 million and KRW 5.3 million. Also, the TCO of electric vehicles compared to diesel vehicles under the current purchase subsidy was estimated to be about KRW 3.6 million lower for business use and about KRW 6.6 million lower for non-business use. These results imply that it is reasonable to lower the unit price of the purchase subsidy even within the same budget. Moreover, the remaining budget could be better spent on upgrading the charging infrastructure, which would reduce the inconvenience of charging for potential buyers.

• Korean Journal of Childcare and Education
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• v.3 no.1
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• pp.1-15
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• 2007

The objective of this study was to investigate the employed mother's work-mother role conflict according to the mother's work variables and parenting time. For this purpose, 202 employed mothers in dual-income family answered the questionnaire. The data were analysed by t-test, F-test, correlations and regressions. The findings of this study were: 1. Mother's role conflict showed significant difference and relationship in mother's work variables(flexibility of duty, irregular duty). 2. Mother's role conflict showed significant difference and relationship in mother's parenting time(mother-child activities, parenting time). 3. Employed mother's flexibility of duty and parenting time were correlated positively with mother's role conflict. Mother's irregular duty and mother-child activities were negatively with mother's role conflict. 4. Employed mother's work variables and parenting time influenced the mother's rolr conflict.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.2
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• pp.185-188
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• 2007

Lately, the modulated EGR system that includes EGR valve and EGR cooler is being installed in diesel engines fur the purpose of the simultaneous reduction of NOx and PM. In this study. we designed and constructed a test bench for the performance evaluation of the modulated EGR system, and tested an electronically controlled EGR valve for 2.0 L diesel engines. The performance of the EGR valve was evaluated in terms of the valve lift behavior. the valve opening/closing response, and the mass flow rate through the valve. The valve lift with respect to the duty ratio of PWM signal was non-linear, and followed a different path fur valve opening and closing, that is, hysteresis. The valve opening response was concluded satisfactory falling within the usual standard response time. For the duty ratio of 40 to 60%, the mass flow rate through the valve was observed to depend on the pressure difference across the valve as well as the duty ratio, while it solely depended on the pressure difference fur the duty ratio above 60%.