• 대한인간공학회지
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• 제35권5호
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• pp.439-447
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• 2016

Objective: The purpose of this study is to design a snow-removing tool using an ergonomic approach. Background: It is necessary to remove snow on the garden of a house or side street to prevent a fall hazard. When a user removes snow using a snow-removing tool, he or she experiences lots of physical discomfort. Therefore it is necessary to design a snow-removing tool to reduce a user's physical discomfort. Method: In this study, a new design for a snow-removing tool was developed considering user needs. The design prototype was compared with an existing tool through electromyography and subjective evaluation. Results: From the comparison evaluation, significant differences between the new design and the existing tool were identified in both muscle fatigue and subjective rating of discomfort. Conclusion: The result showed that the new design is better from the aspect of easing physical discomfort. Application: A new snow-removing tool can be developed using the design so that it can reduce a user's physical discomfort.

• 대한인간공학회지
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• 제33권3호
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• pp.215-227
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• 2014

Objective: The purpose of this study was to evaluate Korea's Honam express train's first- and second-class seat discomfort by using pressure measurement, subjective discomfort rating, and physical compatibility. Background: Over the years, the demand for an express train service is continually increasing. A comfortable ride is important to achieving passenger satisfaction. A train seat plays a significant role in fulfilling passenger seating comfort. With this in view, a field survey and pressure measurements were performed on the selected train seat. Method: The pressure ratio at the body-seat interface (thigh and buttock regions) was measured by the pressure mat system. The interface pressure ratio was calculated and compared. The subjective discomfort rating scale was used to evaluate the subjects' overall feeling. The dimensions of train seats were analysed according to the anthropometric and demographic characteristics of the population data from Size Korea. Results: The results highlighted that the interface pressure ratio was greater while participants sat on the second-class seat than the first-class seat in the left- and right-side thigh regions. Also the pressure ratio was greater for the participants in the 1st~25th percentile height groups (149.8~160.8cm). The subjects rated higher discomfort for the second-class seat than the first-class seat. The physical compatibility results showed that the second-class seat's breadth was inadequate for the 95th and 99th percentile male. Conclusion: Overall, interface pressure measurement, subjective discomfort score and physical compatibility results showed that the second-class seat was more uncomfortable for the passengers than the first-class seat. Application: The adopted methodologies could be used to measure the seating comfort of the train seats.

• KIEAE Journal
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• 제15권4호
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• pp.21-28
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• 2015

Purpose: Although security lights are used to secure pedestrian visibility and safety at nighttime, they can generate light trespass in the neighboring residential space. To prevent this, standards for acceptance limits on vertical illuminance and light pollution by the windows of residential buildings are presented. Method: This study thus representatively selected three types of lamps and, through an evaluation and analysis of the physical and subjective discomfort glare per lamp, proposed a discomfort glare index for each lamp. The evaluation and analysis according to the lamps were conducted through experiments. The variables were the security lights' lamps (NH 100W, MH 70W, LED 50W), installation angles ($0^{\circ}$, $20^{\circ}$), and installation distances (3m, 5m, 7m, 9m). Result: According to the results of the discomfort glare evaluation depending on the angles and distances of the security lights, the following minimum standards are proposed: for NH 100W, a discomfort glare index of 30 and an installation distance of 4m; for MH 70W, a discomfort glare index of 32 and an installation distance of 4m; and, for LED 50W, a discomfort glare index of 31 and an installation distance of 6m, respectively. In addition, this paper recommends the use of MH 70W, when the road width is 4m-6m, and LED 50W, when the road width is over 6m, respectively.

• 산업경영시스템학회지
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• 제24권65호
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• pp.31-40
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• 2001

We Propose an improved shovel design to minimize physical discomfort and the risk of cumulative trauma disorder at shoveling tasks. The specifications of shovels in Korean standard data were scrutinized to check if they met the anthropometric specification of Korean population in 1997. We also applied "Body Map" pictograph and self-conscious checklist to field survey to analyze the discomfort of shoveling task. Thirty male subjects whose age were ranging from 18 to 65 voluntarily participated in the experiment. The measurement results show that shoveling workers were exposed to hazards of CTD's. Especially, when workers were involved in ditch digging and construction their trunk vend more than 120 degree. In order to compare the new designed shovel and the traditional K.S shovel, an analysis of variance was performed and we obtained very strong evidence that the new designed shovel was better in reducing physical discomfort. According to the results from electromyograrn experiment the new shovel contributed to improving subjective comfort level and reducing low back muscle fatigue. For futher study, the research may be extended to determine the relationship among shovel sharpness, type, digging motion and digging force.ing force.

• 한국치위생학회지
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• 제8권4호
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• pp.153-163
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• 2008

The purpose of this study was to investigate the quality of life of clients who treated and equipped prosthesis in Eulji University Hospital in Dae-Jun City. The results of this study were as follows. The oral status of Female had more carious tooth than male had. Carious tooth(p<0.05) and losed tooth(p<0.001) was more popular in older female. The frequency of treated tooth was higher under 59 years old female than over 60 years old(p<0.01). In education category, carious tooth(p<0.05) and losed tooth(p<0.000) was more popular in low education than high education In the score of relation of OHIP-14 category and general characteristic, female was significantly higher than male in dysfunction( p<0.05), physical disorder(p<0.001) and activity disorder(p<0.05). The score was significantly higher in older than younger in dysfunction(p<0.05), physical disorder(p<0.001) and activity disorder(p<0.001). The score of education was significantly higher in low education group than high education group in physical pain (p<0.001), mental discomfort (p<0.001). The score of marriage status was significantly higher in marriaged group than other group in dysfunction (p<0.05) and mental discomfort (p<0.05). In the score of relation of OHIP-14 category and oral status, the score of carious tooth group was significantly higher in dysfunction(p<0.05), physical disorder(p<0.05) and activity disorder(p<0.05). The score of losed tooth group was significantly higher in dysfunction(p<0.05), physical pain (p<0.05), mental discomfort(p<0.05), physical disorder(p<0.05) and activity disorder(p<0.01). The score of non treated tooth group was significantly higher in dysfunction(p<0.05), mental discomfort(p<0.05), social disorder(p<0.05) and activity disorder(p<0.05). In the score of relation of OHIP-14 category and the sort of prosthesis, the score of being bridge group was significantly higher than being crown group in activity disorder(p<0.05). The OHIP-14 category and the number of prosthesis was not significant relationship. These results suggest that the information and services of the process of dental prosthesis based on subjective evaluation should be provided to clients rather than based on clinical evaluation. The continued system of oral management should be developed and provided.

• 한국생활과학회지
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• 제10권4호
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• pp.349-355
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• 2001

The use of bed in Korea has increased steadily, however, intensive survey on the general use and consumer's evaluation of their beds have not been performed sufficiently, yet. Thus, the purpose of this study is to investigate the actual use of the consumer and their degree of evaluation for the component of the bed as well as their feeling of discomfort on the various parts of body. More than one hundred users of commercial beds were responded to the survey. The results obtained were as follows: (1) Complaint about the depression of the mattress and the noise from the bed was apparent in the current use of beds. (2) Important physical variable related to the comfortable sensation of the sleeping was the degree of support in maintaining the natural shape of the spine and waist. Durability and the degree of hardness of the mattress were also important physical parameters of bed perceived by consumer. (3) The degree of discomfort on the back and waist during sleep was closely related to the comfort evaluation of the bed.

• 대한정형도수물리치료학회지
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• 제10권2호
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• pp.73-82
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• 2004

Objectives : In order to develop the measuring tool of visual display terminal (VDT) syndrome and investigate the variables affecting the development of VDT syndrome. Methods : A questionnaire study accompanied with the evaluation of working environment was performed with 42 VDT users from banking operations. Results : As a results of analysis with data colleted by newly developed questionnaire, VDT syndrome included five factors named as eye-related component, and psychological component. general body discomfort component. musculoskeletal component, and skin-related component. The scores of eye-related symptoms was 15.17, scores of psychological symptoms was 7.36, scores of general body discomfort symptoms was 10.52, scores of musculoskeletal symptoms was 9.38, scores of skin-related symptoms was 3.67, and total scores was 46.10. Scores of 2.05 eye fatigue in the level of eye-related symptoms were higher significantly. Scores 50.52 of female was statistically higher than scores 41.67 of male. Conclusions : The subjective symptoms of VDT syndrome scores was significantly associated with gender and age.

• 디자인학연구
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• 제12권1호
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• pp.157-166
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• 1999

컴퓨터의 도입과 함께 VDT 증후군이라는 새로운 사회문제가 제기되고 있다. 다양한 체격의 사용자가 무리 없는 자세로 VDT작업을 수행하기 위해서는 인간공학적인 설계기준이 필요하다. 본 연구에서는 선 연구의 설계지침을 이용하여 설계 권장치수를 먼저 제시하였다. 이에 대찬 타당성 검증을 위해 사용자의 선호치수를 구하였고, 그것과 설계지침에 따른 차이를 분석하였다. 그리고 안락감과 신체불편도 평가를 통한 주관적 평가와 근전도(EMG)분석을 통한 객관적 평가를 사용하여 각 설계치수가 인체에 미치는 영향을 비교분석 하였다. 워크스테이션에서 중요한 키보드의 높이는 팔꿈치보다 높이가 낮다면 손과 손목에 영향을 미치고, 높으면 목과 어깨에 피로를 가져다준다. 본 연구 실험결과 한국인을 위한 키보드책상의 권장치수는 고정식일 때 660mm 조절식일 때 540-774mm를 추천한다. 그 외 설계권장치수는 본문에 제시하였으며 이와 같은 인간공학적 권장치수는 결론적으로 사용자의 신체에 맞게끔 조절범위를 제공하므로 설계 분야에 중요한 기초자료가 되리라본다.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1997년도 춘계학술대회논문집
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• pp.90-94
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• 1997

Many workers like welders are working in squat sitting postures with te object on the ground for an entire work shift. It is suspected that such prolonged squat sitting without any supporting stool would gradually cause musculoskeletal injuries to workers. This study is to quantitatively evaluate the physical stress caused by the prolonged squat sitting and to recommend a safe work/rest schedule for the task with squat sitting posture based on the lab experiment. In this study, 8 healthy student subjects participated in the experiment. They maintained a squat sitting posture for 16 minutes with 4 different stool height conditions: no stool, 10cm hight, 15cm height, 20cm height. Every 2 minutes, the discomfort was subjectively assessed using the magnitude estimation method for the whole body, lower back, upper leg and lower leg. Based on discomfort rating, we found that 10cm height stool relieved the workload most. Discomfort rating results also indicated that 20cm height stool showed the heghest workload, and that there was no difference in workload between 15cm height and no stool. We recommend to provide the workers with 10cm height stool for prolonged squat sitting tasks.

• 대한인간공학회지
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• 제33권6호
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• pp.565-575
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• 2014

Objective: The aim of this study is to evaluate the effect of weight of load and time on the physical workload of repetitive upper-limb tasks with handling light weight loads using EMG and perceived discomfort, and to investigate the relationship between EMG and perceived discomfort for those repetitive tasks of moving light weight loads. Background: Repetitive upper-limb motion is known as one of the main risk factors of musculoskeletal disorders, and a lot of repetitive tasks are carried out while handling light weight loads in the industry. In evaluating the workload of repetitive tasks handling light weight loads, EMG and perceived discomfort can be used, though their relationship in those work conditions are not much investigated. Method: A laboratory experiment with 18 healthy males were conducted to record EMG signals from 5 muscle sites of the right arm and shoulder and rate perceived discomforts for the body parts and the whole body while carrying out repetitive materials-handling tasks for 52min. The subjects were divided into 3 groups which handled the loads of 1kg, 2kg and 3kg, respectively. ANOVAs were conducted to analyze the effects of the weight and time on RMS of EMG amplitude (normalized RMS: NRMS), median frequency of power spectrum of EMG (normalized MDF: NMDF) and perceived discomfort. The correlations between NRMS and NMDF and perceived discomfort were also analyzed. Results: Statistically significant muscular fatigue effects were not found from NRMS and NMDF in most muscles, while there were significant increases of discomfort as the task time elapsed. It was shown that there were an increasing trend of the muscular activity as the weight of load increased and a decreasing trend of median frequency of EMG of upper and lower arms as time elapsed. It was found that there were significant negative correlations between NMDFs from the lower arm and discomfort ratings, though the relationships were weak. Conclusion: It can be concluded that the working conditions adopted in this study were not enough to induce muscular fatigue, while there was significant increase in perceived discomfort. A further study is necessary to integrate the objective and subjective measures for more reliable and sensitive evaluation of workload of repetitive tasks of handling light weight loads. Application: This study can be used as a basic study for the evaluation of workload of repetitive tasks handling light weight loads.