• Journal of the Ergonomics Society of Korea
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• v.28 no.2
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• pp.27-34
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• 2009

The purpose of this study was to evaluate aging (young and old), gender (male and female), and handle shape effects on grip force, finger force, and subjective comfort. Four handle shapes of A, D, I, and V were implemented by a multi-finger force measurement (MFFM) system which was developed to measure every finger force with different grip spans. Forty young (20 males and 20 females) and forty old (20 males and 20 females) subjects participated in twelve gripping tasks and rated their comfort for all handles using a 5-point scale. Grip forces were calculating by summation of all four forces of the index, middle, ring and little fingers. Results showed that young males (283.2N) had larger gripping force than old males (235.6N), while young females (151.4N) had lower force than old females (153.6N). Young subjects exerted the largest gripping force with D-shape due to large contribution of the index and middle fingers and the smallest with A-shape; however, old subjects exerted the largest with I-shape and the smallest with V-shape due to small contribution of the ring and little fingers. As expected, the middle finger had the largest finger force and the little finger had the smallest. The fraction of contribution of index and ring fingers to grip force differed among age groups. Interestingly, young subjects provided larger index finger force than ring finger force, whereas old subjects showed that larger ring finger forces than index finger force in the griping tasks. In the relationship between performance and subjective comfort, I-shape exerting the largest grip force had less comfort than D-shape producing the second largest grip force. The findings of this study can provide guidelines on designing hand tool handle to obtain better performance as well as users' comfort.

• Proceedings of the ESK Conference
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• 1995.04a
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• pp.55-61
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• 1995

We spend about 40% of lifte time on a bed and seek how such amount of time is spent comfort. Bed comfort has been pursuited. The pressure distributions on a bed by body pressure has been considered as one of the most important factors of bed comfort. This study is to quantify the subjective assessment by the body pressure distribution and develop the objective evaluation method of bed comfort. A new measurement system for body pressure on a bed was developed in this study. The thin film pressure sensor (FSR: Force Sensing Resistor) of an elastomer-type was used to prevent the distortion of contact pressure. The pressure distribution is measured by FSR and displayed on the monitor by color-coded contour patterns. Some of the bed test results were described. And the relations between body pressure distribution and bed comfort were evaluated.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.780-787
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• 2013

Virtual Seat Method (VSM) is used in this study for a combined evaluation method (objective & subjective) to determine comfort value of passenger vehicle seat in terms of idle vibration. In the study, a process for applying VSM divided into two stages is established. Two kinds of seat mounting passenger vehicle and six subjects are employed to compare the comfort value obtained by VSM method and by SEAT value. As a conclusion, the results by the two methods were well consistent so that VSM is verified as a method to measure ride comfort of seat in terms of idle vibration at passenger vehicle.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.05a
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• pp.186-189
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• 2002

The footwear such as socks and shoes is the clothing which are necessary to our life. In this study, clothing comfort of the footwear was carried out by physiological responses and subjective evaluation. As a result, the effect to walking comfort by the height of a heel in female shoes became clear. Then suitability evaluation system of shoes was proposed from the measuring results. On the other hands, the clothing comfort of the hosiery was evaluated from ECG analysis. By this analysis, it became clear that the factor which influences the clothing comfort of the hosiery was the clothes pressure in the hosiery. In the future, plane shape of the foot and solid shape must be considered in order to design the hosiery.

• KIEAE Journal
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• v.11 no.3
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• pp.37-42
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• 2011

This study aims to analyze the field survey of thermal comfort in office building with national thermal environment standard. Internal and external temperatures were measured at ten minute intervals and compared in accordance with the national standard for thermal environment. Sixty two workers filled in the questionnaire survey forms five times a day for 40 days. Field monitoring of offices in Seoul, Korea were conducted from 20 July to 28 August. Result for the comfort temperature was set a $26.30^{\circ}C$. This indicates that the 26 degree is reliable for the Korean standard. Indoor temperature standard can reduce energy use by air-conditioned buildings and the temperature would be offer comfort to occupants.

• International Journal of Automotive Technology
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• v.6 no.4
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• pp.383-390
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• 2005

This study proposes an innovative design guideline to assist the evaluation and improvement of the dynamic comfort of vehicle seating. The existing evaluation method for the comfort of vehicle seating was investigated to broach problems in evaluation. It was found that the currently existing evaluation method employs the resonance frequency of the vibration system composed of the seat and the human body and the maximum vibration transmissibility. This study proposes a design guideline aimed at the enhancement of vibration transmission characteristics above the resonance range, particularly within the range of 10-18 Hz. In order to meet this guideline, a seat was constructed out of foam having a low damping coefficient. It was then installed in a vehicle for a driving test. The driving test confirmed the improvement of the dynamic comfort of the seat. The result of evaluation of the improved seat using the SEAT index, an industry standard widely used to evaluate the dynamic comfort of a seat considering the perceptivity characteristics of the human body, showed that the perceptive vibration transmission had reduced by more than $11\%$. The effect of the modification of seat foam was also verified through a subjective assessment of dynamic comfort of the seats.

• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.23-28
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• 2007

In most existing research, it is difficult to evaluate thermal comfort exactly because of reflecting individual ideal or psychological response by subjective questions. Physiological variable was selected in this study to evaluate objectively thermal comfort. MST was appeared very sensitively in indoor temperature and can express correctly thermal comfort of human body. The results of CSV are different each individual feeling sensation, so is difficult to evaluate detailedly thermal comfort unlike TSV. But the results of PP, AIx, ED, SEVR are greatly related to temperature change. So thermal comfort is evaluated more objectively by using PP, AIx, ED, SEVR on behalf of TSV, CSV. Human body was presented physiological feedback by temperature impetus and specially, tendency of heart rate agree with temperature change. Physiological reaction was showed sufficient possibility availing evaluation index of thermal comfort. In the future another one needs to review beside the selected physiological variable.

• Journal of the Korean Society of Safety
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• v.35 no.3
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• pp.58-63
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• 2020

At the construction site of the driving site, the pile rebound and penetration measurements are performed manually to determine the end point of the driving operation, thereby causing the measurer to be exposed to a death accident. In this study, in order to eliminate the risk of this work, a non-contact penetration measuring device was developed and usability evaluation was conducted. The penetration measuring device is manufactured based on the ultrasonic sensor, and can be combined with the pile to deliver the data in real time, and the delivered data can be output in real time on the portable PC and the final penetration can be calculated. Usability evaluation on the device was conducted by comparison with manual work. Usability evaluation was largely evaluated on measured values, subjective comfort, and body parts comfort. The result of the measured value tended to overestimate the value measured manually by the measuring device, which is similar to the previous research. In terms of subjective comfort and body part comfort, overall satisfaction was higher than the manual method when using the measuring device. Taken together, these results indicate that it is possible to use the rudder measuring device in place of manual work in the construction site, and it is judged that the worker's comfort is greatly increased by using the measuring machine. The results of this study suggest that the use of non-contact measuring device in the field can be used as basic data to support them.

• Journal of the Ergonomics Society of Korea
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• v.35 no.5
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• pp.343-359
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• 2016

Objective:In this study, we designed working clothes for livestock farmers to wear in spring and autumn to improve their work efficiency, conducted a physiological test on their performance, and evaluated their comfort. Background: In recent years, livestock farming in Korea has expanded, yet farmers' safety and sanitation levels remain low in hazardous environments that include organic dust, toxic gas, and heat stress, as well as the risk of accidents. Furthermore, most livestock farmers wear ordinary or dust-resistant clothes that are unsuitable for rearing livestock and compromise their safety and health. Thus, it is important to design specialized working clothes for livestock farmers that are comfortable and that minimize their health and safety risks. Method: To this end, we examined the literature on livestock (poultry, swine, and cattle) farmers' safety and sanitation issues, designed appropriate working clothes, and tested them in terms of sensory feel, physiological response, and subjective comfort. Results: The respondents expressed satisfaction with the new working clothes. The results of a physiological test showed a decline in temperature and humidity inside the clothes, a lower pulse rate, and a lower oxygen intake compared to the measurements taken when famers wore their previous working clothes. This indicates a fall in heat stress and fatigue, which was mostly consistent with the results of the assessment of subjective comfort. Conclusion: The results of the analysis show an improvement in the comfort of the new working clothes compared to the dust-resistant clothes that are widely worn. Based on this study, the new working clothes need to be further tested and evaluated to improve the design. Application: This study is expected to contribute to designing better working clothes for livestock farmers.

• Fashion & Textile Research Journal
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• v.16 no.3
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• pp.485-491
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• 2014

This study verified the effect of summer flight ventilation developed in a previous study based on wearing comfort evaluation. Seven healthy males in their twenties volunteered for this experiment conducted in aclimatic chamber. The experiment consisted of three consecutive periods of rest (20 minutes), running on a treadmill (10 minutes) and recovery (20 minutes). A comparative evaluation was conducted on the general flight suit which had no ventilation holes and summer flight suit that use subjective satisfaction measures and objective measures. The subjective satisfaction was evaluated according to the criteria of temperature sensation, wet sensation, thermal comfort and fatigue sensation. The objective satisfaction was measured by skin temperature, microclimate (temperature and humidity), sweat rate and thermography. The comparative wearing evaluation identified the summer flight suit decreased the temperature between skin and suit by $0.42^{\circ}C$ (upper arm), $0.9^{\circ}C$ (calf) and the skin temperature by $0.3^{\circ}C$ (shoulder), $0.4^{\circ}C$ (upper arm), $0.5^{\circ}C$ (calf) as compared to the general flight suit. The humidity inside the summer flight suit decreased at head (7.73%), shoulder (5.86%), upper arm (5.26%), and calf (8.73%) compared to the one inside the general flight suit. Thermography showed that the air flowed through ventilation holes (neck and armpit). The design of ventilation holes applied to the summer flight suit can be applicable to overall clothing that requires thermal comfort such as dust-free garments, mechanical clothing and combat uniforms.