• 대한인간공학회지
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• 제19권3호
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• pp.93-107
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• 2000

The excessive exposure to powered hand tools can cause damage to nerves, impair blood circulation, and musculoskeletal damage. The symptoms associated with hand-arm vibration syndrome (HAVS) include numbness, tingling, pain and subsequent reduced dexterity of the hands. This study was performed to report the prevalence of the HAVS and evaluate its related factors among the workers using powered hand tools. Total 282 workers in 11 plants of Kyungki and Inchon areas were examined. A standard symptom questionnaire was developed and administered to collect information on personal characteristics, work history, operating conditions, tool characteristics, and subjective symptoms of HAVS. Mean values (standard deviations) of the age, the duration of powered hand tools used, and the daily hours using powered hand tools were 38.3(8.9) years, 79.3(62.2) months and 6.0(2.6) hours, respectively. 132 workers(46.8%) showed vibration-induced white finger symptoms according to the Taylor-Pelmear classification, and 30 workers(10.6%) were interfered with the work. The results of a multiple logistic regression analysis controlling for age and daily working hours showed that smoking, work duration, weight of tools, and continuous work over 2 hours were significantly associated with the symptom of HAVS.

• 산업경영시스템학회지
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• 제22권52호
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• pp.43-52
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• 1999

In this study, the vibration damping characteristics of the powered hand tools transmitted in hand-arm system were examined and compared. The types of powered tools for the experiment are general typed drill, impact drill, grinder, and wire brush. To analyze the characteristics of vibration damping, the magnitude of acceleration of vibration on X, Y, and Z direction at tool, hand, wrist, and the joint between forearm and upper arm were measured respectively. The results indicated that impact drill generated the highest value of acceleration of vibration among the four types of tools used in the experiments. The highest value of the amount of acceleration of vibration was found in the direction of Y. And the amount of acceleration of vibration was significantly affected by the type of tool, type of work, and pushing forces. As become the more distant from the tool, the smaller the amount of acceleration of vibration. Also, the bigger the pushing force at the tool, the higher the acceleration of vibration.

• 한국산업보건학회지
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• 제33권2호
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• pp.103-114
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• 2023

Objectives: This study was conducted to evaluate hand-arm vibration (HAV) exposure levels due to the use of power hand tools and to evaluate the determinants in the automobile assembly process. Methods: The exposure level to HAV was evaluated for 30 work lines in five assembly processes (body, engine, chassis, door, and design) that use air-powered tools and battery-powered tools and operate in circulation for two hours. The 2-hr equivalent energy vibration acceleration, A (2), of the task was measured. The 8-hr equivalent energy vibration acceleration, A (8), was estimated in consideration of the number of tasks that can be performed per day by each process. In addition, a survey on the working environment was conducted with workers exposed to vibration. Results: The geometric mean of the HAV exposure level, A (2), for a total of 30 tasks was 2.51 m/s², and one case was 10.30 m/s², exceeding TLV (2hr). The HAV exposure level of A (8) was evaluated from 1.03 m/s² to 5.36 m/s². A (2) showed a statistically significant difference (P<0.01) for each process, and the chassis process (GM=3.90 m/s²) was the highest. The larger the tool size and the longer the tool length, the higher was the vibration acceleration when using a battery-powered tool than an air-powered tool (P<0.01). Battery-powered tool users showed higher dissatisfaction on all items than did air-powered tool users. Conclusions: As a result of this study, it is necessary to implement a program to reduce the HAV exposure levels.

• 산업공학
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• 제17권3호
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• pp.375-383
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• 2004

The purpose of this study is to investigate the characteristics of vibration induced by the powered hand tools used in the automobile assembly lines, and estimate the prevalence of vibration syndrome. The acceleration levels of four major powered hand tools were measured using the ISO 5349 method along with the time of exposure to the vibration of the hand tools. Four-hour-energy-equivalent frequency-weighted accelerations ranged from $1.27m/s^2$ to $2.58m/s^2$, After exposure to vibration for 12.6 years, about 10% of the workers using impact ranches were expected to develop Raynaud's disease. For the workers using grinders, 16.6% of the workers were expected to develop Raynaud's disease. The results would be of help in developing the guidelines of local vibration control.

• 대한인간공학회지
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• 제19권2호
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• pp.75-86
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• 2000

In this study, the characteristics of transmitted vibration on HAS(hand-arm system) were identified to evaluate physical load due to the work surface orientation, tool weight and push force during powered drilling tasks. The characteristics of transmitted vibration on work surface orientation showed that the acceleration of transmitted vibration on horizontal work surface was higher than that on the vertical work surface. Regarding the characteristics of transmitted vibration on tool weight, the vibration acceleration level becomes lower as the tool weight becomes heavier. The amount of transmitted vibration on hand-arm system was decreased down to the tool weight of 2.4kg. However, as the tool weight becomes heavier than 2.8kg, the amount of transmitted vibration was increased and had peak value at 3.2kg of tool weight. Regarding the characteristics of transmitted vibration on push force, the vibration acceleration level goes higher, as the push force becomes larger. The characteristics of transmitted vibration on the axis of vibration showed that the direction of $Z_h$ had the highest acceleration compared to the direction of $X_h$, and $Y_h$. The direction of $X_h$, $Y_h$ and $Z_h$ had the highest acceleration of transmitted vibration on the hand, wrist and elbow, respectively. The results of this study showed that the condition which affect the lowest physical load to the subject on the powered drilling task would be working with the 2.4kg of tool weight on the vertical work surface.

• 대한인간공학회지
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• 제26권1호
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• pp.29-37
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• 2007

This study was performed to evaluate the characteristics of transmitted vibration to hand-arm system under different work posture while operating a light-weighted powered hand grinder. For the experiment, 8 different types of wrist posture (natural, unlar-flexion, radual-flexion, flexion, extension, complex posture, and etc.) and 3 types of feed force (20[N], 50[N], 70[N]) were considered. 10 male subjects were employed to polish metal plate with a hand grinder. All of them were normal and healthy with no history and symptom of the work related musculoskeletal disorders in the dominant hand. Vibration acceleration data were recorded with sampling rate, 2048[Hz]. In addition, unweighted overall R.M.S. acceleration at the tool and wrist, and transmissibility between them were used to evaluate factors from the recorded tri-axial vibration acceleration. The results indicate that transmissibility of natural wrist posture was significantly higher than others. In addition, as the feed force becomes larger, the vibration was transmitted in large quantities to hand-arm system through radius.

• 산업경영시스템학회지
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• 제23권56호
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• pp.45-53
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• 2000

A laboratory experiment was conducted to investigate the effects of body posture and of different types of common non-powered hand tools on maximum volitional torque exertion capabilities of Korean. Fifteen males and 15 females were participated in the experiment. Each subject exerted maximum volitional torque in 15 different body postures while using five different common non-powered hand tools. Results of the data analysis showed that, for both males and females, the magnitude of torque exertion is significantly affected by the type of tool and posture. Also the result indicated that females exerted only about 51.5% of torque when compared to that of males. This result is different with the general findings in the field of ergonomics that the muscular strength of female is usually 65% to 75% of male. It suggests that application of same profile of muscular strength of female as in the western population should be carefully considered in oriental countries since females in this region may possess less physical capability compare to that of western females in terms of percentage muscular strength of males. Profiles of maximum torque capabilities of Koreans are provided.

• International Journal of Advanced Culture Technology
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• 제11권4호
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• pp.56-61
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• 2023

The present study explored a comprehensive investigation of university professors' perspectives on the implementation of ChatGPT - an artificial intelligence-powered language model - in their teaching practices. A diverse group of 30 university professors responded to a questionnaire about the level of their interest in implementing the tool, willingness to apply it, and concerns they have regarding the intervention of ChatGPT in higher education setting. The results showed that the participants are highly interested in employing the tool into their teaching practice, and find that the students are likely to benefit from using ChatGPT in classroom settings. On the other hand, they displayed concerns regarding high depandency on data, privacy-related issues, lack of supports required, and technical contraints. In today's fast-paced society, educators are urged to mindfully apply this inevitable generative AI means with thoughtfulness and ethical considerations to and for their learners. Relevant topics are discussed to successfully intervene AI tools in teaching practices in higher education.

• 한국농촌생활과학회지
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• 제8권1호
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• pp.7-13
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• 1997

In this study we examined the greenhouse worker's work load to test the efficiency of the developed vehicles (hand operated vehicle (HV), simple battery-powered autonomous vehicle (AV)). The subject of this study were healthy adult females who had experience in growing crops. We measured workers' heart rate, blood Pressure. rectal temperature, mean skin temperature, oxygen consumption and blood lactate level as a physiological index of work load. The results of this study are as follows : The test group using experimental vehicle showed the lower heart rate (mean$\pm$S.D. for HV, AV respectively 74$\pm$5, 75$\pm$3 beats/min, p＜0.01) than the control group (84$\pm$8beat/min) not using experimental vehicle and the lower systolic blood Pressure (HV, AV respectively 109$\pm$8, 109$\pm$9 mmHg, p＜0.01) than the control group (121$\pm$11 mmHg), and lower rectal temperature(HV, AV respectively 37.0$\pm$0.1, 36.8$\pm$0.2$^{\circ}C$, p＜0.01) than the control group (37.0$\pm$0.2$^{\circ}C$), and the less oxygen consumption (HV, AV respectively 2.13$\pm$0.09, 1.66$\pm$0.52$m\ell$/kg/min, p＜0.01) than the control group(2.43$\pm$0.12$m\ell$/kg/min), and the lower blood lactate level (HV, AV respectively 2.03$\pm$1.00, 1.66$\pm$0.52mmol, p＜0.01) than the control group (2.43$\pm$0.12mmol). Judging from these results, these experimental vehicles for greenhouse workers can be confirmed as a useful tool. It is suggested that these vehicles would alleviate the peasant's syndrome including muscle fatigue and musculoskeletal disease usually caused by working in an uncomfortable posture.