• 대한인간공학회지
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• 제26권3호
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• pp.59-65
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• 2007

In this study, six grip spans (45mm-65mm) were tested to evaluate the effects of handle grip span and user's hand size on maximum grip strength, individual finger force, and subjective ratings of comfort using a digital dynamometer with individual force sensors. Forty-six males were assigned into three hand size groups according to their hand lengths. Results showed that overall 55mm and 50mm grip spans were the most comfortable sizes and associated with the highest grip strength in the maximum grip force exertions, whereas 65mm grip span was rated as the least comfortable size as well as the lowest grip strength. In the interaction effect of grip span and hand size, small and middle hand sized participants rated the best preference and the least preference grip spans differently with large hand sized participants. With respect to the analysis of individual finger force, the middle finger force was the strongest and the highest contribution to the total finger force, followed by ring, index and little fingers. In addition, it was noted that each finger had a different optimal grip span for exerting maximum force resulting in a bowed contoured shaped handle for two-handle hand tools. Thus, the grip spans for two-handle hand tools might be designed according to the users' hand and finger anthropometrics to maximize performance and subjective perception of comfort.

• 대한인간공학회지
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• 제29권6호
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• pp.889-895
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• 2010

This study compared the effects of craniocervical flexion exercise with conservative cervical flexion exercise in workers with chronic neck pain. Subjects were randomly allocated to two groups: control (n=20) and experimental group (n=20), respectively. The conservative exercise for the control group consisted of cervical flexion exercise, whereas the experimental group performed a craniocervical flexion exercise. To compare the two groups, the visual analogue scale (VAS) for a pain, neck disability index (NDI) for a neck disability scale, and cross sectional area (CSA) of longus colli muscle using ultrasound image were assessed on pre-intervention, post-intervention, and 2 weeks follow-up. 2-way repeated ANOVA was used with Bonferroni post-hoc test. (1) There were significant main effects (within and between groups) (p<0.05) and interaction effect (p<0.05) in VAS. Post-hoc test revealed that there were significant differences in all pair-wise comparisons. (2) There were significant main effects (within and between groups) (p<0.05) and interaction effect (p<0.05) in NDI. Post-hoc test revealed that there were significant differences between pre-intervention and post-intervention, pre-intervention and 2 weeks follow-up. (3) There were significant main effects (within and between groups) (p<0.05) and interaction effect (p<0.05) in CSA of longus colli muscle. Post-hoc test revealed that there were significant differences in all pair-wise comparisons. The findings indicate that craniocervical flexion exercise are more effective for improving pain, neck disability, and CSA of longus colli muscle than cervical flexion exercise in workers with chronic neck pain.

• 대한인간공학회지
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• 제27권4호
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• pp.109-117
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• 2008

Compared to the existing PC which uses a mouse and a keyboard, the touchscreen-based portable PC allows the user to use fingers, requiring new operation methods. However, current touchscreen-based web browser operations in many cases involve merely having fingers move simply like a mouse and click, or not corresponding well to the user's sensitivity and the structure of one's index finger, making itself difficult to be used during walking. Therefore, the goal of this study is to develop finger gestures which facilitate the interaction between the interface and the user, and make the operation easier. First, based on the frequency of usage in the web browser and preference, top eight functions were extracted. Then, the users' structural knowledge was visualized through sketch maps, and the finger gestures which were applicable in touchscreens were derived through the Meaning in Mediated Action method. For the front/back page, and up/down scroll functions, directional gestures were derived, and for the window closure, refresh, home and print functions, letter-type and icon-type gestures were drawn. A validation experiment was performed to compare the performance between existing operation methods and the proposed one in terms of execution time, error rate, and preference, and as a result, directional gestures and letter-type gestures showed better performance than the existing methods. These results suggest that not only during the operation of touchscreen-based web browser in portable PC but also during the operation of telematics-related functions in automobile, PDA and so on, the new gestures can be used to make operation easier and faster.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1998년도 춘계학술대회논문집
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• pp.188-193
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• 1998

The purpose of the study is to develop a numerical model based on experimental data to estimate the thermal comfort in the driving room of a motorcar. For the ecperiments, three air temperature level of 21, 23, 25 .deg. C are set to measure variable such as average skin temperature, R-R interval, the comfort sensation, and the performance level. By performing statistical analysis with the results obtainted, it is observed that two physiological factors-average skin temperature and R-R interval have significant relation with the thermal comfort in the driving room. Thus, those two factors are included as parameters in the proposed model to estimate the thermal comfort.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1996년도 추계학술대회논문집
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• pp.41-46
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• 1996

This paper suggests the methodology for the ergonomic assessment of the navigation system driver that corresponds to the subjective measurement of the driver's mental workload by rating his or her own driving task. For this approach, Revision of NASA-Task Load Index (RNASA-TLX) was developed which translated and revised the version of NASA-TLX that is generally accepted an efficient and powerful method for evaluating the in-vehicle information system. To venify RNASA- TLS, an experiment was conducted in a real road situation, because the result of the laboratory approach is uncertain and has the differences from the real road test.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2004년도 춘계 종합학술대회 논문집
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• pp.535-539
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• 2004

This paper is concerned with structurizing contents of the ergonomic resources and constructing DB of these resources. Through this internet system developed using ultra 2 DB Server, Sun Solaris(UNIX) OS, UniSql DBMS, Apache Web server, the interface (www.gamsung.or.kr), by which ergonomic resources can be provided, has been completed. Information retrieval concerning ergonomic resources produced by the project "Business of Development in Technology of Human Sensibility Ergonomics" is possible. For example, 35 reports and 262 ergonomic characteristics issued from the first step of this project, 255 ergonomic characteristics issued from the second step. In addition, there are also voice data, sound data, expression data, questionnaire data, sensibility data, and information about researchers, manufactories, references.

• Safety and Health at Work
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• 제9권2호
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• pp.164-171
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• 2018

Background: In recent years, the interest in health and safety in the workplace has increased. Agriculture is one of the human work activities with the highest risk indexes. Studies on risk perception of agricultural workers are often referred to as specific risk factors (especially pesticides), but the risk perception plays an important role in preventing every kind of accident and occupational disease. Methods: The aim of this research is to test a new method for understanding the relation between risk perception among farmers and the main risk factors to which they are exposed. A secondary aim is to investigate the influence of training in risk perception in agriculture. The data collection was realized using a questionnaire designed to investigate the risk perception; the questionnaire was given to a sample of 119 agricultural workers in central Italy. Through the use of the "principal components analysis" it was possible to highlight and verify the latent dimensions underlying the collected data in comparison with scales of attitudes. Results: Results show that the highest percentage of strong negative attitude is among the people who have worked for more years, while farmers who have worked for fewer years have a marked positive attitude. Conclusion: The analysis of the questionnaires through the synthetic index method (Rizzi index) showed that agricultural workers involved, in particular the elderly workers, have a negative attitude towards safety; workers are hostile to safety measures if they have not attended special training courses.

• Anatomy and Cell Biology
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• 제57권2호
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• pp.172-182
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• 2024

This study aimed to evaluate the superficial anatomy, kinesiology, and functions of the hand to reveal its morphometry and apply the findings in various fields such as prosthetic hand and protective hand support product design. We examined 51 young adults (32 females, 19 males) aged between 18-30. Hand photographs were taken, and measurements were conducted using ImageJ software. Pearson correlation analysis was performed to determine the relationship between personal information and the parameters. The results of the measurements showed the average lengths of finger segments: thumb (49.5±5.5 mm), index finger (63.9±4.1 mm), middle finger (70.7±5.2 mm), ring finger (65.5±4.8 mm), and little finger (53.3±4.3 mm). Both females and males, the left index finger was measured longer than the right index finger. The right ring finger was found to be longer than the left in both sexes. Additionally, length differences between fingers in extended and maximally adducted positions were determined: thumb-index finger (56.1±6.2 mm), index-middle finger (10.7±4.1 mm), middle-ring finger (10.8±1.4 mm), and ring-little finger (25.6±2.7 mm). Other findings included the average radial natural angle (56.4°±10.5°), ulnar natural angle (23.4°±7.1°), radial deviation angle (65.2°±8.2°), ulnar deviation angle (51.2°±9.6°), and grasping/gripping angle (49.1°±5.8°). The average angles between fingers in maximum abduction positions were also measured: thumb-index finger (53.4°±6.5°), index-middle finger (17.2°±2.6°), middle-ring finger (14.3°±2.3°), and ring-little finger (32.1°±7.0°). The study examined the variability in the positioning of proximal interphalangeal joints during maximum metacarpophalangeal and proximal interphalangeal flexion, coinciding with maximum distal interphalangeal extension movements. The focal points of our observations were the asymmetrical and symmetrical arches formed by these joints. This study provides valuable hand parameters in young adults, which can be utilized in various applications such as prosthetic design, ergonomic product development, and hand-related research. The results highlight the significance of considering individual factors when assessing hand morphology and function.

• 대한인간공학회지
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• 제32권6호
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• pp.503-509
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• 2013

Objective: The purpose of this study is to analyze the individual finger force between dominant hand and non-dominant hand and to investigate an effect of the individual finger on the total grip strength depending on dominant hand and non-dominant hand. Background: Many studies on the ratio of the grip force between dominant hand and non-dominant hand has been researched. While a 10% rule which is a ratio of the grip force between dominant hand and non-dominant hand has been applied in most studies, studies on the rate of the individual finger force between dominant hand and non-dominant hand have been insufficiently researched. Method: The experiment was preceded with 17 subjects (male, mean 25.8 ages). The individual finger force and total grip strength were measured using pliers being able to change the grip span from 45 to 80mm. Results: The difference of total grip strength between dominant hand and non-dominant hand is following 10% rule. However, the difference of individual finger force between dominant hand and non-dominant hand are not same as the difference of total grip strength. Especially in the case of grip span with 50mm, the differences between total grip strength, index finger, middle finger, ring finger, and little finger were $9.87{\pm}14.80%$, $8.95{\pm}37.17%$, $13.71{\pm}28.27%$, $6.77{\pm}24.35%$, $39.29{\pm}42.46%$, respectively, with p=0.018 of statistical significance. Additionally, the results of regression analysis in 50 and 60mm of grip span showed that the difference in ring finger affected the most to the total grip strength; and the effects followed in order of index finger, middle finger, and little finger. Conclusion: Our study suggests that an effect of individual finger and grip span of pliers have to be considered when explaining the difference of the total grip strength between dominant hand and non-dominant hand. Application: This result is expected to be used for designing ergonomic hand tool.

• 한국화재소방학회논문지
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• 제27권3호
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• pp.85-93
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• 2013

본 연구에서는 소방대원이 수행하는 업무 중 중량물을 다루어야 하는 작업에 대한 분류 및 정량적 분석(NLE, 3DSSPP)을 수행하여 향후 소방대원의 중량물 관련 작업에 대한 위험도를 예측하고, 관련 위험도를 감소시키기 위한 기초 자료를 도출하고자 하였다. 도출된 위험도 등급은 위험도 점수가 3점부터 9점까지 총 7단계로 구성되었다. 가장 위험도가 높은 1등급은 나타나지 않았으며 인명구조 작업이 두 번째로 높은 2등급에 속하는 것으로 나타났다. 3등급은 파괴기구 활용, 환자 들어올리기작업 등으로 나타났다. 본 연구 결과들은 소방대원의 허리 부상을 포함하는 근골격계 질환 예방을 위한 작업방법 및 장비의 개선, 교육 프로그램의 개발에 기본 토대가 될 수 있다고 판단되며, 소방대원들의 근골격계 질환에 대한 지속적인 예방을 위해서는 본 연구의 골격을 토대로 한 추후 심층적인 조사와 연구가 시급하다고 사료된다.