• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.580-586
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• 1994

Psychophysical method는 육체의 자극과 그 자극에 반응하는 인간의 감각과의 관계를 다루는 것으로, 드는 작업시의 하중에 관한 외국의 연구에서 자주 사용되고 있는 방법중의 하나이다. Psychophysical method를 사용하면 8시간 작업을 실제로 하지 않고서도 훨씬 적은 시간의 실험을 통하여 8시간 작업시와 근사한 결과를 얻을 수 있는 장점이 있다. 따라서 이 방법은 시간과 경비를 줄인다는 이점이 있어 많이 사용되고 있다. 본 연구에서는 외국인과 스트레스를 느끼는 정도, 그리고 신체적 차이가 있는 한국의 피실험자에게도 psychophysical method가 적용 가능한가를 알아보기 위하여 우리나라 작업자와 학생에 대하여 연구를 하였다. 20분과 8시간 동안의 드는 작업을 실시한 결과, 작업자군은 20분 동안의 드는 실험에서 8시간 동안의 작업이 육체에 주는 스트레스의 96%를 예측할 수 있었으나 학생군에 있어서는 76%밖에 예측하지 못하였다. 따라서 우리나라에서는 작업 경험이 부족한 학생들에게 psychophysical method를 적용할 경우 보정이 필요하나, 작업 경험이 풍부한 작업자들에게는 용이하게 적용할 수 있음을 알 수 있었다.

• Journal of the Ergonomics Society of Korea
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• v.15 no.2
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• pp.51-62
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• 1996

This research utilized the psychophysical methodology, where secrw drivers are used, to determine the effects of i) the location and orientation of work objects, and ii) wearing gloves, on ratings of perceived exertion at various body parts. The validity of the psychophysical methodology in determining a preferred work pace was also studied. The subjects drove screws with a screw driver into thick wooden sheet at three vertical and three horizontal locations. They drove serews for 3 minutes at each location and assessed the condition using the psychophysical scale. The results showed that only the vertical location was a significant factor in determining the discomfort ratings. Driving screws at elbow height on the vertical surface and with the lower arm close to the body on the horizontal surface were the work locations with the smallest ratings of perceived discomfort. Wearing gloves had significant effects on reducing the pain of the hand. From the experiment in which a comfortable work pace was identified using 20 minute psychophysical adjustment, it was found that the psychophysical method is sensitive to workers perception of the physical stress when the upper limbs are employed. This was confirmend by the high correlation between the psychophysical results and EMG measurement.

• Journal of the Ergonomics Society of Korea
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• v.13 no.2
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• pp.57-63
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• 1994

This paper summarizes recent research in the use of the psychophysical method of adjustment to establish acceptable parameters for upper extremity work activities. Results from these studies show that this psychophysical approach can provide reliable guidelines based upon realistic job conditions which involve one or more risk factors for cumulative trauma. It is also shown that this method provides advantages over other psychophysical methods as well as current biomechanical and physioligical criteria.

• Journal of the Ergonomics Society of Korea
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• v.21 no.1
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• pp.81-93
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• 2002

This study aims to provide joint angles of comfort for females, based on the psychophysical scaling method. Ten female subjects participated in the experiment for measuring perceived discomfort for varying joint motions. The subjects were instructed to maintain given joint motions for a minute, and to rate their perceived discomfort for the motions during a minute's rest by using the free modulus method of the magnitude estimation. Joint angles of comfort were calculated from the regression equations based on the experimental results, in which levels of joint motions were used as independent variables and perceived discomforts as dependent variables. The results showed that joint angles of comfort for the joint motions investigated were much smaller than full range of motions for corresponding joint motions. The ratios of joint angle of comfort to its range motion for the hip were found to be smallest of all joint motions dealt with in this study, and those for the neck were the largest. In addition, comfortable joint angles for females were much smaller than those for males. It is recommended that when designing or evaluating workplaces ergonomically, different comfortable joint angles should be applied according to workers' or population's gender.

• Fashion & Textile Research Journal
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• v.21 no.1
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• pp.88-95
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• 2019

The purpose of this study was to figure out the various characteristics of the thickness sensation among elements of tactile sensation using psychophysical method. Firstly, panel screening was processed to select sensitive thickness panel using the triangle test. As a result of discriminating the paper thickness difference from 1 to 4 pieces, the female students perceived the thickness difference more sensitively than the male students (p<.05). Secondly, JND (Just Noticeable Difference) was obtained at percentage of stimulus detection rate in order to detect the degree of thickness difference by psychophysical method. It was found that the difference threshold of the entire group was about 0.125mm, with male group being about 0.178mm and female group being about 0.095mm. Thirdly, Weber's law was used to find the minimum discrimination difference between the stimuli. The experiments were conducted by increasing the paper's base thickness from 1.950mm to 1.330mm, and it was found that the difference tendency increased when the size of the basic stimulus increased. At this time, the minimum discrimination difference increased, but the Weber' fraction was not proportional to the magnitude of the stimulus. The significance of this study was that sensory evaluation was applied to research in the fields of clothing science and it seems effective to further screen and train sensitive students as material discrimination experts.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.271-274
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• 2002

The YCbCr color is widely used for digital video. In this paper, six different histogram algorithms are defined; the corresponding test images are then produced; and these images are then evaluated by observers using psychophysical techniques such as pair comparison; and show observer's preference data based on the psychophysical experiment.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2003.11a
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• pp.1311-1318
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• 2003

최근 흡한 속건성은 사이언스 소재로 가장 보편적으로 이용되고 있는 소재 성능이다. 하지만 아직 제대로 된 측정 평가법이 존재하고 있지 않고, 몇몇 의류업체에서는 단순히 객관적 속성만을 측정하고 있다. 본 연구에서는 객관적 속성인지들의 연속적이 값들이 실제 인체에서는 얼마만큼의 변별력으로 인식되는지 정신물리학적 측정법으로 최소 자극치(PSE)를 구하여 등급을 나누어 보았다. 시료는 흡한속건성 직물로 가장 많이 이용되고 있는 Coolmax(R), Coolever(R), 친수성 이중직물의 3개 그룹으로 나누었고, 측정 인자로 객관적 속성인자는 cling force, drying time을, 이와 대응하는 주관적 속성인자는 clinginess, dampness를 측정하고 각각의 PSE값을 구하였다. 그룹에 따라 객관적 속성인자 값들이 이라고 느끼는 PSE 구간까지 도달하는 시간과 속력을 측정하여 그룹마다의 흡한속건 등급을 정하였다. 또한 설계된 소재의 성능을 간접적으로 알 수 있는 transmissibility라는 인자도 도입하여 수분 전달성도 객관적으로 살펴볼 수 있었다. Clinginess, Dampness, Transmissibility 각 인자들을 평가해본 결과 Coolmax(R) 가 가장 우수함을 알 수 있었다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.11a
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• pp.76-80
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• 2001

The weight of shoes may serve as a determining factor of perceived comfort and feel to the consumer in their purchase and repurchase decisions of footwear. People, however, seem to have trouble in accurately judging the feeling of weight of shoes on their feet. This paper made a psychophysical study of subjects′ sensitivity to weight on their feet and in their hands. The experiment consisted of 3 tests according to the motions people make when they evaluate the feel of shoes: 1) vertical lifting of a shoe on the foot ("hefting" in on the foot) 2) swing the shod foot back and forth; 3) holding and lifting a shoe by hand ("hefting" it in the hand). The method of constant stimuli and magnitude estimation were used for the experiment with 20 subjects. Weber′s ratios and the power law exponents obtained for each of the three tests were 0.156 and 0.713, 0.108 and 0.970, and 0.065 and 1.249, respectively in the same order of the previously listed tests.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.259-262
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• 2003

Fabric hand is ultimately a subjective response to physical stimuli, but there are clearly practical advantage in the development and commercial trading of textile fabrics to be gained from the replacement of the traditional subjective tactile assessment by an objective measurement evaluation method. Moreover, the reliable objective measurement method for warp knitted fabrics have not developed yet, despite their increasing importance. (omitted)

• Proceedings of the ESK Conference
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• 1995.10a
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• pp.13-17
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• 1995

A Psychophysical scaling method called magnitude estimation is frequently used to evaluate human sensation to physical stimuli. This paper described the procedure of magnitude estimation data analysis which consists of four modulus; reponse space, CMM(Cross-Modality Matdhing)/merge, standardization, scale building & data analysis method. This procedure is being developed as an expert system in which the four analysis modulus are programmed so that a novice user can perform the analysis.