• Title/Summary/Keyword: Psychophysics

Search Result 22, Processing Time 0.022 seconds

Mathematical Modeling Analysis of the Human Visual Filters (인간시각필터의 수학적 모델링 해석)

  • Lee, Jeok-Sik
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.38 no.6
    • /
    • pp.617-629
    • /
    • 2001
  • The mathematical models for the receptive field of simple cells in the human visual system have been developed in the areas of psychophysics, physiology and neuroscience. The various models used in the fields of digital image processing and computer vision include Gator complex, Gaussian derivatives and Hermite functions. In this paper, the effective widths for the models are derived based on the space-frequency uncertainty principle. The center frequency and parameters related to the models are determined in accordance with the human visual filters, and resultant bandwidths are analyzed. Furthermore, the characteristics of space and frequency for the models is analyzed and compared to the experimental data obtained from psychophysics.

  • PDF

차량산업에서의 인체진동

  • 장한기
    • Journal of KSNVE
    • /
    • v.12 no.2
    • /
    • pp.113-119
    • /
    • 2002
  • ‘인체진동(human vibration)’은 진동에 대한 인체의 반응(human response to vibration)의 줄임말로써, 환경으로서의 진동 및 충격이 인체에 미치는 물리적, 심리적 영향을 측정, 평가하는 것을 주요 연구대상으로 한다. 인체진동 분야의 주요 연구개발은 객관적인 물리량의 산출뿐만 아니라 주관적인 느낌을 수치화하는 작업을 포함하기 때문에 기계진동, 생체역학(biodynamics)과 기본적인 역학과 심리측정학(psychometrics), 심리물리학(psychophysics), 인간공학(ergonomics) 등과 같이 다양한 종류의 학문이 요구된다.(중략)

An Integrated Model of Static and Dynamic Measurement for Seat Discomfort

  • Daruis, Dian Darina Indah;Deros, Baba Md;Nor, Mohd Jailani Mohd;Hosseini, Mohammad
    • Industrial Engineering and Management Systems
    • /
    • v.10 no.3
    • /
    • pp.185-190
    • /
    • 2011
  • A driver interacts directly with the car seat at all times. There are ergonomic characteristics that have to be followed to produce comfortable seats. However, most of previous researches focused on either static or dynamic condition only. In addition, research on car seat development is critically lacking although Malaysia herself manufactures its own car. Hence, this paper integrates objective measurements and subjective evaluation to predict seat discomfort. The objective measurements consider both static and dynamic conditions. Steven's psychophysics power law has been used in which after expansion; ${\psi}\;=\;a+b{\varphi}_s^{\alpha}+c{\varphi}_v^{\beta}$ where ${\psi}$ is discomfort sensation, ${\varphi}_s^{\alpha}$ is static modality with exponent ${\alpha}$ and ${\varphi}_v^{\beta}$ is dynamic modality with exponent ${\beta}$. The subjects in this study were local and the cars used were Malaysian made compact car. Static objective measurement was the seat pressure distribution measurement. The experiment was carried out on the driver's seat in a real car with the engine turned off. Meanwhile, the dynamic objective measurement was carried out in a moving car on real roads. During pressure distribution and vibration transmissibility experiments, subjects were requested to evaluate their discomfort levels using vehicle seat discomfort survey questionnaire together with body map diagram. From subjective evaluations, seat pressure and vibration dose values exponent for static modality ${\alpha}$ = 1.51 and exponent for dynamic modality ${\beta}$ = 1.24 were produced. The curves produced from the $E_{q.s}$ showed better $R_{-sq}$ values (99%) when both static and dynamic modalities were considered together as compared to Eq. with single modality only (static or dynamic only R-Sq = 95%). In conclusion, car seat discomfort prediction gives better result when seat development considered both static and dynamic modalities; and using ergonomic approach.

The MPI CyberMotion Simulator: A Novel Research Platform to Investigate Human Control Behavior

  • Nieuwenhuizen, Frank M.;Bulthoff, Heinrich H.
    • Journal of Computing Science and Engineering
    • /
    • v.7 no.2
    • /
    • pp.122-131
    • /
    • 2013
  • The MPI CyberMotion Simulator provides a unique motion platform, as it features an anthropomorphic robot with a large workspace, combined with an actuated cabin and a linear track for lateral movement. This paper introduces the simulator as a tool for studying human perception, and compares its characteristics to conventional Stewart platforms. Furthermore, an experimental evaluation is presented in which multimodal human control behavior is studied by identifying the visual and vestibular responses of participants in a roll-lateral helicopter hover task. The results show that the simulator motion allows participants to increase tracking performance by changing their control strategy, shifting from reliance on visual error perception to reliance on simulator motion cues. The MPI CyberMotion Simulator has proven to be a state-of-the-art motion simulator for psychophysical research to study humans with various experimental paradigms, ranging from passive perception experiments to active control tasks, such as driving a car or flying a helicopter.

Human Sensitivity Responses to Vibrotactile Stimulation on the Hand : Measurement of Differential Thresholds (진동식 촉각 자극에 대한 손의 상대적 민감도 반응)

  • Lee, Seong-Il
    • Journal of the Ergonomics Society of Korea
    • /
    • v.18 no.3
    • /
    • pp.1-12
    • /
    • 1999
  • This study investigated human operator's perceptual and psychophysical responses to vibrotactile stimulation on various parts of the hand. Using a small vibrotactile display, the effects of three mechanical parameters consisting vibrotactile stimulations, i.e., vibration frequency, pulse-width modulation duty cycle, and number of contactors, on differential thresholds were examined at five different loci of the hand. It was observed that differential threshold varies with vibration frequency and number of active contactors. Differential sensitivity was the greatest at the vibration frequency of 120 Hz. The differential sensitivity was not found to be affected by loci on the hand. The area of stimulation on the hand was also found to be significant in that the sensitivity increased with the number of active contactors. It should be noted that the conclusions from this study generally correspond to those from the previous study on the absolute sensitivity. which means that tactile sensitivity to vibrotactile stimulations can be controlled with a systematic and consistent passion for emulating normal everyday contact on human hands in teleoperation and virtual reality applications.

  • PDF

Evaluation of idle vibration beated by cooling fan imbalance (팬 작동에 따른 비팅성 아이들 진동 평가)

  • Park, Jinhan;Ahn, Sejin;Jeong, Weuibong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2014.10a
    • /
    • pp.247-249
    • /
    • 2014
  • The beating phenomenon occurs because of various causes, when idle vibration was happened. In this study, the beating phenomenon was divided into several parameters and controlled by the parameter. It was hypothesized that the beating parameter is related to discomfort of idle vibration. The three-down one-up method was performed for evaluating discomfort of controlled vibrations, which is widely used in the field of psychophysics. As a result in pilot test, a subject responds beating vibration more discomfort than normal idle vibration. In the future, the study will be implemented to know how much the parameters of beating signal affect to the discomfort at idle vibration in passenger vehicle.

  • PDF

A PSYCHOPHYSICAL STUDY ON WEIGHT SENSITIVITY BY THE FOOT AND HAND

  • Nah, Ken
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
    • /
    • 2001.11a
    • /
    • pp.76-80
    • /
    • 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.

  • PDF

Multimodal Curvature Discrimination of 3D Objects

  • Kim, Kwang-Taek;Lee, Hyuk-Soo
    • Journal of the Institute of Convergence Signal Processing
    • /
    • v.14 no.4
    • /
    • pp.212-216
    • /
    • 2013
  • As virtual reality technologies are advanced rapidly, how to render 3D objects across modalities is becoming an important issue. This study is therefore aimed to investigate human discriminability on the curvature of 3D polygonal surfaces with focusing on the vision and touch senses because they are most dominant when explore 3D shapes. For the study, we designed a psychophysical experiment using signal detection theory to determine curvature discrimination for three conditions: haptic only, visual only, and both haptic and visual. The results show that there is no statistically significant difference among the conditions although the threshold in the haptic condition is the lowest. The results also indicate that rendering using both visual and haptic channels could degrade the performance of discrimination on a 3D global shape. These results must be considered when a multimodal rendering system is designed in near future.

A Psychophysical Approach to evaluating the perceived image quality of CRT: White Uniformity Quality (CRT 모니터의 감성품질 정량화를 위한 심물리학적 접근: White Uniformity 품질 평가)

  • Lee, Uk-Gi;Kim, Seong-Hwan;Lee, Seon-Gyu;Lee, Gwang-Hui;Kim, Sang-Su
    • Journal of the Ergonomics Society of Korea
    • /
    • v.20 no.2
    • /
    • pp.59-70
    • /
    • 2001
  • White uniformity is one of the important inspection factors determining the image quality of CRT screen. In the full white pattern, white uniformity means the degree of uniform distribution of white color across the whole screen. To elicit the sensitivity factors affecting the decision of the white uniformity quality, experiments in which participants were confronted with 6 evaluation points embedded in 3 measurement groups on a CRT screen were conducted to gather the psychophysical data that are the level of white uniformity subjects perceived and CA100 produced. These data were used to develop a modified CIE1976 equation for calculating white uniformity. Performance comparison between the original CIE1976 equation and the modified equation was conducted in terms of accuracy test and magnitude estimation. It was concluded the modified equation is more sensitive in the change of white uniformity, compared to the original CIE1976 equation.

  • PDF