• Title/Summary/Keyword: driver stress

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The Effect of Emotional Labor for Job Stress in Bus Drivers (버스 운전직 근로자들의 감정노동이 직무 스트레스에 미치는 영향)

  • Kim, Hee Ryang;Yi, Yunjeong;Lee, Keum-Ja;Kim, Hee Gerl
    • Korean Journal of Occupational Health Nursing
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    • v.23 no.1
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    • pp.20-27
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    • 2014
  • Purpose: This study was conducted to identify the association between emotional labor and job stress in bus drivers, as well as to propose management strategies for job stress. Methods: The study was conducted in February 2013 and involved 182 bus drivers working in the Gyeonggi area. Results: emotional labor was $9.5{\pm}2.34$ on average, and job stress was higher than the median of the same indicator among Korea's workers in the areas of physical environment, job autonomy, and relationship conflicts. Factors that affected job stress was lower if the subjects' Higher values for emotional labor indicated a higher level of job stress. Conclusion: To reduce among drivers, the following measures are necessary: increase the comfort of the driver's seat within the vehicle, provide adequate rest between bus headways, provide comfortable in-house rest facilities, and establish physical training spaces to reduce musculoskeletal disorders as well as programs for reducing back pain. In addition, relationship conflicts may be relieved by increasing job autonomy as much as possible, by granting autonomous control of working hours and bus headways, as well as by banning long work hours. Moreover, various club activities, exercise programs, and counseling programs that workers can be involved in together may be beneficial. This study is significant in that it identified the relationship of the bus drivers' emotional labor and job stress, which has previously been ignored as a research topic. Through its results, this study provides baseline data for the preparation of management strategies that can address the job stress of bus drivers.

Design of the High Brightness LED Driver IC with Enhanced the Output Current Control Function (출력전류 제어 기능이 향상된 고휘도 LED 구동 IC 설계)

  • Han, Seok-Bung;Song, Ki-Nam
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.9-9
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    • 2010
  • In this paper, High Brightness LED driver IC using new current sensing circuit is proposed. This LED driver IC can provide a constant current with high current precision over a wide input voltage range. The proposed current-sensing circuit is composed of a cascode current sensor and a current comparator with only one reference voltage. This IC minimizes the voltage stress of the MOSFET from the maximum input voltage and has low power consumption and chip area by using simple-structured comparator and minimum bias current. The LED current ripple of the designed IC is in ${\pm}5%$ and a tolerance of the average LED current is lower than 2.43%. This shows much improved feature than the previous method. Also, protections for input voltage and operating temperature are designed to improve the reliability of the designed IC. Designed LED driver IC uses $1{\mu}m$ X-Fab. BiCMOS process parameters and electrical characteristics and functioning are verified by spectre(Cadence) simulation.

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LED Driver Compatible with Both Electronic and Magnetic Ballasts (전자식 및 자기식 안정기 동시 호환 가능한 LED 구동회로)

  • Gu, Hyun-Su;Choi, Yoon;Kang, Jeong-Il;Han, Sang-Kyoo
    • The Transactions of the Korean Institute of Power Electronics
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    • v.21 no.1
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    • pp.42-48
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    • 2016
  • Light-emitting diode (LED) drivers are recently replacing fluorescent lamps; these drivers can operate adaptively with various ballasts without modifying and removing such ballasts. To satisfy these trends, a LED driver that is compatible with both electronic and magnetic ballasts is proposed in this study. Unlike conventional LED drivers, the proposed driver has a ballast recognition circuit and a mode selection circuit to operate ballasts at optimal conditions. Therefore, it features low voltage stress, high efficiency, and good compatibility with both electronic and magnetic ballasts. Moreover, it can be compatible with a wide selection of ballasts from various manufacturers. To confirm the validity of the proposed LED driver, results of the theoretical analysis and experimental verification performed on a 15 W-rated prototype are presented.

Correlation of Occupational Stress Index with 24-hour Urine Cortisol and Serum DHEA Sulfate among City Bus Drivers: A Cross-sectional Study

  • Du, Chung-Li;Lin, Mia Chihya;Lu, Luo;Tai, John Jen
    • Safety and Health at Work
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    • v.2 no.2
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    • pp.169-175
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    • 2011
  • Objectives: The questionnaire of occupational stress index (OSI) has been popular in the workplace, and it has been tailored for bus drivers in Taiwan. Nevertheless, its outcomes for participants are based on self-evaluations, thus validation by their physiological stress biomarker is warranted and this is the main goal of this study. Methods: A cross-sectional study of sixty-three city bus drivers and fifty-four supporting staffs for comparison was conducted. Questionnaire surveys, 24-hour urine cortisol testing, and blood draws for dehydroepiandrosterone-sulfate (DHEA-S) testing were performed. The measured concentrations of these biological measures were logarithmically transformed before the statistical analysis where various scores of stressor factors, moderators, and stress effects of each OSI domain were analyzed by applying multiple linear regression models. Results: For drivers, the elevated 24-hour urine cortisol level was associated with a worker's relationship with their supervisor and any life change events in the most recent 3 months. The DHEA-S level was higher in drivers of younger age as well as drivers with more concerns relating to their salary and bonuses. Non-drivers showed no association between any stressor or satisfaction and urine cortisol and blood DHEA-S levels. Conclusion: Measurements of biomarkers may offer additional stress evaluations with OSI questionnaires for bus drivers. Increased DHEA-S and cortisol levels may result from stressors like income security. Prevention efforts towards occupational stress and life events and health promotional efforts for aged driver were important anti-stress remedies.

Design of Digital-clothing that can Detect Driver's Bio-signal and Position (운전자의 생체신호 및 위치 파악이 가능한 디지털 의류 설계)

  • Lee, Min-hye;Jeong, Dong-myong;Shin, Seong-yoon;Jeon, Tae-il;Choi, Jae-seok;Jeong, Gi-soo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.10a
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    • pp.171-173
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    • 2018
  • The poor working conditions of transit drivers not only lead to mental stress and fatigue accumulation of workers, but also to the main causes of mass transit accidents. Stress and fatigue accumulation are closely related to the vital signs because they affect the psychological and physical health. In this paper, we designed a digital garment which can measure driver's health condition by measuring electrocardiogram, pulse rate and body temperature. Also proposed a system that transmits the measured bio-signal to the smartphone app via Bluetooth and transmits the current position of the driver to the server by using the built-in GPS of the smartphone, assuming there is something wrong.

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Real-time Intelligent Health and Attention Monitoring System for Car Driver (실시간 지능형 운전자 건강 및 주의 모니터링 시스템)

  • Shin, Heung-Sub;Jung, Sang-Joong;Seo, Yong-Su;Chung, Wan-Young
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.5
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    • pp.1303-1310
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    • 2010
  • Recently, researches related with automative mechanism have been widely studied to increase the driver's safety by continuously monitoring the driver's health condition to prevent driver's drowsiness. This paper describes the design of wearable chest belt for ECG and reflectance pulse oximetry for SpO2 sensors based on wireless sensor network to monitor the driver's healthcare status. ECG, SpO2 and heart rate signals can be transmitted via wireless sensor node to base station connected to the server. Intelligent monitoring system is designed at the server to analyze the SpO2 and ECG signals. HRV (Heart Rate Variability) signals can be obtained by processing the ECG and PPG signals. HRV signals are further analyzed based on time and frequency domain to determine the driver's drowsiness status.

A Simple ZVZCS Sustain Driver for a Plasma Display Panel

  • Yi Kang-Hyun;Han Sang-Kyoo;Choi Seong-Wook;Kim Chong-Eun;Moon Gun-Woo
    • Journal of Power Electronics
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    • v.6 no.4
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    • pp.298-306
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    • 2006
  • A high efficiency and low cost sustain driver for a plasma display panel (PDP) utilizing a current pumping method is proposed. The main concept of the proposed circuit is using the current source to charge and discharge the panel. As a result, all power switches can achieve zero voltage switching (ZVS) and every auxiliary switch can also achieve zero current switching (ZCS). Since the inductor current can compensate for the discharge current, the current stress of all the power switches can be reduced considerably. Furthermore, it has features such as a simpler structure, less mass, lower cost, and lower electromagnetic interference than in previous circuits.

A novel integrated a-Si:H gate driver

  • Lee, Jung-Woo;Hong, Hyun-Seok;Lee, Eung-Sang;Lee, Jung-Young;Yi, Jun-Shin;Bae, Byung-Seong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1176-1178
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    • 2007
  • A novel integrated a-Si:H gate driver with high reliability has been designed and simulated. Since the a-Si:H TFT is easily degraded by gate bias stress, we should optimize the circuit considering the threshold voltage shift. The conventional circuit shows voltage drop at the input stage by threshold voltage of the TFT, however, the proposed circuit dose not shows voltage drop and keeps constant regardless of threshold voltage shift of the TFT.

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Increase the reliability of the gate driver for amorphous TFT displays

  • Wu, Bo-Cang;Shiau, Miin-Shyue;Wu, Hong-Chong;Liu, Don-Gey
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1301-1304
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    • 2008
  • In this study, we used a multiple phase scheme for the clock in the dual-pull-down driver for TFT display panels. In this scheme, the turn-on time for the transistors in the dual-pull-down structure was reduced from 1/2 to 1/4 or 1/8 of the period cycle time. While keeping proper operation of the transistor size of circuit was fine tuned to achieve an optimal performance. The relation between the active time and the transistor dimensions was obtained for the optimal design.

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A Research on the Wheelchair Carrier for Disabled Driver (장애인 휠체어 캐리어에 관한 연구)

  • Lee, S.C.;Park, S.S.
    • Journal of rehabilitation welfare engineering & assistive technology
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    • v.6 no.1
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    • pp.9-15
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    • 2012
  • In this paper, the feasibility of a wheelchair carrier for the disabled own driver is checked kinematically to fit one of current domestic vans by drawings, design. A van with 9 passengers is selected for the modification to attach the wheelchair carrier and test the operation in real situation. The trajectory and motion process are studied to protect from the interception with outside body of van, and the conceptual design is proceeded kinematically. For the detail design, the stress analysis and driving mechanism with power supply must be studied and selected basically.

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