• 제목/요약/키워드: Duty rate

검색결과 366건 처리시간 0.043초

송전급 피뢰기용 ZnO 바리스터 소자의 전기적 특성 (Electrical Characteristics of ZnO Varistor for Transmission Class Arrester)

  • 김석수;박춘현;조이곤;박태곤
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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    • pp.179-182
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    • 2004
  • ZnO varistor for transmission class arrester$({\Phi}65{\times}20mm)$ of 10kA(Class 3) grade was recently developed in korea and is tested for the properties by switching surge operating duty test to know the line discharge class and complex surge property in electric properties. To find out changing rate of residual voltage before and after lightning impulse residual voltage testing, the sample is cool to room temperature after finishing switching surge operating duty test, and the rate is good as 1.0~1.7%. The element had been considered as applicable ZnO varistor for electricity transmission from the test results of state conterl, switching surge operating duty, thermal stability and above test. But various test should be required for actual application because this is a part of the to be needed for application.

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DS-SS방식을 이용한 유성 버스트 통신의 도통율 개선 (Improvement of duty rate on Meteor Burst Communication using DS-SS system)

  • 권혁숭
    • 한국통신학회논문지
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    • 제28권9A호
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    • pp.669-677
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    • 2003
  • MBC(meteor burst communications)는 그 전송로의 많은 장점에도 불구하고 도통율이 수%이하로 낮다는 큰 결점이 있다. 이를 위해 큰 경제적 부담 없이 전송 채널의 도통율을 개선하는 방법으로서 참조부호 방식을 이용한 DS(direct sequence)-SS(spread spectrum)방식을 적용하였다. 이 방식은 동기신호의 포착이나 유지에 소요되는 시스템을 생략할 수가 있어서, MBC가 가지는 경제성을 만족하면서 전송채널의 도통율을 개선할 수가 있다. 이 방법으로 개선되는 효과는 수신신호가 약한 환경에서 보다 더 큰 것으로 나타나는데 시뮬레이션에 의하면 평균 버스트 길이가 50ms 인 환경에서는 처리이득이 10dB만 되어도 버스트 길이는 220%를 초과하여 160ms 가 되며 발생빈도는 3.1 배가 증가한다는 것을 알 수가 있었다.

기계 시스템 생산 작업관리자 직무 분석에 의한 안전직무교육 개발에 관한 연구 (A Study on Development of Safety Duty Education According to Production Manager Job Analysis in the Mechanical System)

  • 양광모;김창식
    • 대한안전경영과학회지
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    • 제19권1호
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    • pp.63-71
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    • 2017
  • As the demand for automation (or autonmation) or clean workplace has grown, the interest in the knowledge and skill regarding safety is rising in manager duty. Moreover, the importance of severity rate of injury has increased due to the enlargement of industry scale, even safety management area has developed. Thus, it is important that production managers, the core of the line process, realize the safety in their production line, even if a safety manager acts as a staff. However, in the duty oriented National Competency Standard (NCS), the education about the safety duty of production management part is insufficient. According to NCS, it is calculated production managers receive only 6.7% of whole safety education regarding the duty related the safety management for production manager in mechanical industry. However, the ability in safety is more demanded from production managers as the concept of "production and safety" turns into the concept of "production with safety". And then in this paper, we will compare and analyze the safety management duty in Korean NCS and the safety management duty in State Leaders Connecting Learning to Work in US manufacturing industry, in terms of the duty of the production manage in mechanical industry (05). And, we will develop the safety duty education system for production manager, by classifying the safety education in domestic mechanical industry into knowledge education, skill education, and attitude education with using AHP(Analytic Hierarchy Process).

小型디젤機關에서 CVS-75 모드에 따른 디젤 酸化觸媒裝置의 排出가스 低減에 關한 實驗的 硏究 (An Experimental Study on Exhaust Gas Reduction of Diesel Oxidation Catalyst by CVS-75 Mode in Light Duty Diesel Engine)

  • 한영출;김종춘;오용석
    • 한국대기환경학회지
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    • 제15권4호
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    • pp.457-461
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    • 1999
  • Recently, increasing usage of diesel vehicle, many countries try to reduce the pollutant materials by emission regulation standard. Particularly, in our country, the supplement ratio of diesel vehicle is high, and air pollution by particulate matter(PM) is very serious. So, in theoretical study wer analyzed the formation principle of gaseous emission and PM, the characteristics of CVS-75 mode. In experimental study, we tested exhaust gas reduction of emission and PM, the characteristics of CVS-75 mode. In experimental study, we tested exhaust gas reduction of disel oxidation catalyst(DOC) by CVS-75 mode in light duty diesel vehicle. In case of an automobiletest with the 2,956cc diesel engine which DOC was equipped, CVS-75 mode which is similar to driving conditions on the road was chosen as the restrictive mode of light duty diesel automobile in our country. According to the Pt, the reduction rate of exhaust emission was estimated with using 0.1% high sulfur fuel and 0.05% low sulfur fuel.

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Plasma Display Panel용 산화마그네슘 박막의 산화영역에서의 스퍼터 성막기술 (A sputtering technique of magnesium oxide thin film in oxide mode for plasma display panel)

  • 최영욱;김지현
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 C
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    • pp.1874-1875
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    • 2004
  • A high rate deposition sputtering process of magnesium oxide thin film in oxide mode has been developed using a 20 kW unipolar pulsed power supply. The powersupply was operated at a maximum constant voltage of 500 V and a constant current of 40 A. The pulse repetition rate and the duty were changed in the ranges of 10 ${\sim}$ 50 kHz and 10 ${\sim}$ 60 %, respectively. The deposition rate increased with increasing incident power to the target. Maximum incident power to the magnesium target was obtained by the control of frequency, duty and current. The deposition rate of a moving state was 9 nm m/min at the average power of 1.5 kW. This technique is proposed to apply high through-put sputtering system for plasma display panel.

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산화 마그네슘 박막의 스퍼터 제조기술 (Sputtering technique for magnesium oxide thin films)

  • 최영욱
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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    • pp.1560-1561
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    • 2006
  • A high rate deposition sputtering process of magnesium oxide thin film in oxide mode has been developed using a 20 kW unipolar pulsed power supply. The power supply was operated at a maximum constant voltage of 500 V and a constant current of 40 A. The pulse repetition rate and the duty were changed in the ranges of $10{\sim}50\;kHz$ and $10{\sim}60%$, respectively. The deposition rate increased with rising incident power to the target. Maximum incident power to the magnesium target was obtained by the control of frequency, duty and current. The deposition rate of a moving state was 9 nm m/min at the average power of 1.5 kW.

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병원 간호사의 선호근무시간대에 관한 연구 (A Study on Hoslital Nurses' Preferred Duty Shift and Duty Hours)

  • 이경식;정금희
    • 대한간호
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    • 제36권1호
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    • pp.77-96
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    • 1997
  • The duty shifts of hospital nurses not only affect nurses' physical and mental health but also present various personnel management problems which often result in high turnover rates. In this context a study was carried out from October to November 1995 for a period of two months to find out the status of hospital nurses' duty shift patterns, and preferred duty hours and fixed duty shifts. The study population was 867 RNs working in five general hospitals located in Seoul and its vicinity. The questionnaire developed by the writer was used for data collection. The response rate was 85.9 percent or 745 returns. The SAS program was used for data analysis with the computation of frequencies, percentages and Chi square test. The findings of the study are as follows: 1. General characteristics of the study population: 56 percent of respondents was (25 years group and 76.5 percent were "single": the predominant proportion of respondents was junior nursing college graduates(92.2%) and have less than 5 years nursing experience in hospitals(65.5%). For their future working plan in nursing profession, nearly 50% responded as uncertain The reasons given for their career plan was predominantly 'personal growth and development' rather than financial reasons. 2. The interval for rotations of duty stations was found to be mostly irregular(56.4%) while others reported as weekly(16.1%), monthly(12.9%), and fixed terms(4.6%). 3. The main problems related to duty shifts particularly the evening and night duty nurses reported were "not enough time for the family, " "afraid of security problems after the work when returning home late at night." and "lack of leisure time". "problems in physical and physiological adjustment." "problems in family life." "lack of time for interactions with fellow nurses" etc. 4. The forty percent of respondents reported to have '1-2 times' of duty shift rotations while all others reported that '0 time'. '2-3 times'. 'more than 3 times' etc. which suggest the irregularity in duty shift rotations. 5. The majority(62.8%) of study population found to favor the rotating system of duty stations. The reasons for favoring the rotation system were: the opportunity for "learning new things and personal development." "better human relations are possible. "better understanding in various duty stations." "changes in monotonous routine job" etc. The proportion of those disfavor the rotating 'system was 34.7 percent. giving the reasons of"it impedes development of specialization." "poor job performances." "stress factors" etc. Furthermore. respondents made the following comments in relation to the rotation of duty stations: the nurses should be given the opportunity to participate in the. decision making process: personal interest and aptitudes should be considered: regular intervals for the rotations or it should be planned in advance. etc. 6. For the future career plan. the older. married group with longer nursing experiences appeared to think the nursing as their lifetime career more likely than the younger. single group with shorter nursing experiences ($x^2=61.19.{\;}p=.000;{\;}x^2=41.55.{\;}p=.000$). The reason given for their future career plan regardless of length of future service, was predominantly "personal growth and development" rather than financial reasons. For further analysis, the group those with the shorter career plan appeared to claim "financial reasons" for their future career more readily than the group who consider the nursing job as their lifetime career$(x^2$= 11.73, p=.003) did. This finding suggests the need for careful .considerations in personnel management of nursing administration particularly when dealing with the nurses' career development. The majority of respondents preferred the fixed day shift. However, further analysis of those preferred evening shift by age and civil status, "< 25 years group"(15.1%) and "single group"(13.2) were more likely to favor the fixed evening shift than > 25 years(6.4%) and married(4.8%)groups. This differences were statistically significant ($x^2=14.54, {\;}p=.000;{\;}x^2=8.75, {\;}p=.003$). 7. A great majority of respondents(86.9% or n=647) found to prefer the day shifts. When the four different types of duty shifts(Types A. B. C, D) were presented, 55.0 percent of total respondents preferred the A type or the existing one followed by D type(22.7%). B type(12.4%) and C type(8.2%). 8. When the condition of monetary incentives for the evening(20% of salary) and night shifts(40% of. salary) of the existing duty type was presented. again the day shift appeared to be the most preferred one although the rate was slightly lower(66.4% against 86.9%). In the case of evening shift, with the same incentive, the preference rates for evening and night shifts increased from 11.0 to 22.4 percent and from 0.5 to 3.0 percent respectively. When the age variable was controlled. < 25 yrs group showed higher rates(31.6%. 4.8%) than those of > 25 yrs group(15.5%. 1.3%) respectively preferring the evening and night shifts(p=.000). The civil status also seemed to operate on the preferences of the duty shifts as the single group showed lower rate(69.0%) for day duty against 83. 6% of the married group. and higher rates for evening and night duties(27.2%. 15.1%) respectively against those of the married group(3.8%. 1.8%) while a higher proportion of the married group(83. 6%) preferred the day duties than the single group(69.0%). These differences were found to be statistically all significant(p=.001). 9. The findings on preferences of three different types of fixed duty hours namely, B, C. and D(with additional monetary incentives) are as follows in order of preference: B type(12hrs a day, 3days a wk): day shift(64.1%), evening shift(26.1%). night shift(6.5%) C type(12hrs a day. 4days a wk) : evening shift(49.2%). day shift(32.8%), night shift(11.5%) D type(10hrs a day. 4days a wk): showed the similar trend as B type. The findings of higher preferences on the evening and night duties when the incentives are given. as shown above, suggest the need for the introductions of different patterns of duty hours and incentive measures in order to overcome the difficulties in rostering the nursing duties. However, the interpretation of the above data, particularly the C type, needs cautions as the total number of respondents is very small(n=61). It requires further in-depth study. In conclusion. it seemed to suggest that the patterns of nurses duty hours and shifts in the most hospitals in the country have neither been tried for different duty types nor been flexible. The stereotype rostering system of three shifts and insensitiveness for personal life aspect of nurses seemed to be prevailing. This study seems to support that irregular and frequent rotations of duty shifts may be contributing factors for most nurses' maladjustment problems in physical and mental health. personal and family life which eventually may result in high turnover rates. In order to overcome the increasing problems in personnel management of hospital nurses particularly in rostering of evening and night duty shifts, which may related to eventual high turnover rates, the findings of this study strongly suggest the need for an introduction of new rostering systems including fixed duties and appropriate incentive measures for evenings and nights which the most nurses want to avoid, In considering the nursing care of inpatients is the round-the clock business. the practice of the nursing duty shift system is inevitable. In this context, based on the findings of this study. the following are recommended: 1. The further in-depth studies on duty shifts and hours need to be undertaken for the development of appropriate and effective rostering systems for hospital nurses. 2. An introduction of appropriate incentive measures for evening and night duty shifts along with organizational considerations such as the trials for preferred duty time bands, duty hours, and fixed duty shifts should be considered if good quality of care for the patients be maintained for the round the clock. This may require an initiation of systematic research and development activities in the field of hospital nursing administration as a part of permanent system in the hospital. 3. Planned and regular intervals, orientation and training, and professional and personal growth should be considered for the rotation of different duty stations or units. 4. In considering the higher degree of preferences in the duty type of "10hours a day, 4days a week" shown in this study, it would be worthwhile to undertake the R&D type studies in large hospital settings.

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Investigating the Au-Cu thick layers Electrodeposition Rate with Pulsed Current by Optimization of the Operation Condition

  • Babaei, Hamid;Khosravi, Morteza;Sovizi, Mohamad Reza;Khorramie, Saeid Abedini
    • Journal of Electrochemical Science and Technology
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    • 제11권2호
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    • pp.172-179
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    • 2020
  • The impact of effective parameters on the electrodeposition rate optimization of Au-Cu alloy at high thicknesses on the silver substrate was investigated in the present study. After ensuring the formation of gold alloy deposits with the desired and standard percentage of gold with the cartage of 18K and other standard karats that should be observed in the manufacturing of the gold and jewelry artifacts, comparing the rate of gold-copper deposition by direct and pulsed current was done. The rate of deposition with pulse current was significantly higher than direct current. In this process, the duty cycle parameter was effectively optimized by the "one factor at a time" method to achieve maximum deposition rate. Particular parameters in this work were direct and pulse current densities, bath temperature, concentration of gold and cyanide ions in electrolyte, pH, agitation and wetting agent additive. Scanning electron microscopy (SEM) and surface chemical analysis system (EDS) were used to study the effect of deposition on the cross-sections of the formed layers. The results revealed that the Au-Cu alloy layer formed with concentrations of 6gr·L-1 Au, 55gr·L-1 Cu, 24 gr·L-1 KCN and 1 ml·L-1 Lauryl dimethyl amine oxide (LDAO) in the 0.6 mA·cm-2 average current density and 30% duty cycle, had 0.841 ㎛·min-1 Which was the highest deposition rate. The use of electrodeposition of pure and alloy gold thick layers as a production method can reduce the use of gold metal in the production of hallow gold artifacts, create sophisticated and unique models, and diversify production by maintaining standard karats, hardness, thickness and mechanical strength. This will not only make the process economical, it will also provide significant added value to the gold artifacts. By pulsating of currents and increasing the duty cycle means reducing the pulse off-time, and if the pulse off-time becomes too short, the electric double layer would not have sufficient growth time, and its thickness decreases. These results show the effect of pulsed current on increasing the electrodeposition rate of Au-Cu alloy confirming the previous studies on the effect of pulsed current on increasing the deposition rate of Au-Cu alloy.

Influence of Injection Rate Shaping on Combustion and Emissions for a Medium Duty Diesel Engine

  • Benajes, J.;Molina, S.;Rudder, K. De;Rente, T.
    • Journal of Mechanical Science and Technology
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    • 제20권9호
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    • pp.1436-1448
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    • 2006
  • This paper describes the effects of injection rate shaping on the combustion, fuel consumption and emission of $NO_x$ and soot of a medium duty diesel engine. The focus is on the influence of four different injection rate shapes, square type 1, square type 2, boot and ramp, with a variation of maximum injection pressure and start of injection (SOI). The experiments were carried out on a 1 liter single cylinder research diesel engine equipped with an amplifier-piston common rail injection system, allowing the adjustment of the injection pressure during the injection event and thus injection rate as desired. Two strategies to maintain the injected fuel mass constant were followed. One where rate shaping is applied at constant injection duration with different peak injection pressure and one strategy where rate shaping is applied at a constant peak injection pressure, but with variable injection duration. Injection rate shaping was found to have a large effect on the premixed and diffusion combustion, a significant influence on $NO_x$ emissions and depending on the followed strategy, moderate or no influence on soot emission. Only small effects on indicated fuel consumption were found.

근무지속시간에 따른 경계근무와 CCTV모니터링근무의 생체리듬변화 차이 연구 (A Study on Changes in the Biorhythm in Guard Duties and CCTV Monitoring Works for Work Duration)

  • 최동재;한승훈;권창기;박영진;김병태;김병찬
    • 시큐리티연구
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    • 제35호
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    • pp.125-149
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    • 2013
  • 본 연구에서는 경호경비현장에서 이루어지고 있는 실제적인 경호경비원들의 경계근무와 CCTV 모니터링 요원들의 스트레스를 확인하고, 비교 평가하기 위해 심박동변이(heart rate variability)를 통하여 생체리듬의 변화를 관찰하였다. K대학교 경호학과 학생 9명을 대상으로 실제 근무와 유사한 환경에서 경계근무와 CCTV 모니터링근무를 150분간 실시하였다. 30분 간격으로 자율신경검사를 관찰한 결과 HRT는 모니터링 근무가 경계근무 보다 더 낮게 나타났으며, 안정시, 근무 30분과 60분보다 90분, 120분, 150분은 낮게 나타났다. SDNN은 모니터링 근무가 더 높게 나타났으며, 근무 30분과 60분 보다 근무 150분에서 더 낮게 나타났다. 자율신경검사에서는 TP는 근무형태에 따른 집단 간 차이는 나타나지 않았으며, 근무 30분 보다 근무 150분에 더 높은 시기적 차이를 보였다. 근무형태와 근무시간의 상호작용은 나타났다. LF는 근무 60분 보다 근무 150분에 높은 시기간의 차이를 보였다. HF는 모니터링 근무 집단에 높게 나타났으며, 근무 30분 보다 근무 120분과 150분에서 더 높게 나타났다. 근무형태와 근무시간의 상호작용도 나타났다. LF/HF ratio는 경계근무 집단이 더 높게 나타났으며, 시기 간에 차이와 함께 근무형태와 근무시간의 상호작용도 나타났다. 모니터링 근무가 경계근무보다 부교감신경활동이 더 활발함에 따라 더 낮은 심기능 활동을 보였다. 매일 반복되는 장기간의 모니터링 근무는 VDT증후군이나 신경피로에 노출될 가능성이 더 높은 것으로 나타났다.

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