- Sound Environmental Improvement in Open Classroom by Sound Masking
- Publish Date : 2014/03/01 Vol.14
- Authors :
- Yutaka TOMITA, Fujita Health University
Kazutami SUKA, Keio University
- Report Outline :
- Original article
Appeared on Ergonomics of Human System Interaction, Vol. 14, No. 1, 9/14, 2012
Recently many student experiment training rooms are becoming open type, in which partitions separate the rooms, and lecturers give instructions. Although in the open space experiment training rooms students feel open, easy to move and easy to arrange experiment subjects, voices of lecturers interfere so much and as a consequence the interference interrupt the lectures in next compartments.
To make better sound environment which does not annoy lectures was aimed by generating particular masking noise, which reduces the interference from other lecturers. The generated noise was kept at the same sound level as air-conditioning equipments.
so the best suited masking noise using multiple sound samples was devised.
This paper describes the outline and the assessment experiment of this sound masking system specific to our student experimental laboratory.
- Effect of Thermal Information Presentation to Mouse for Photographic Image Browsing
- Publish Date : 2014/03/01 Vol.14
- Authors :
- Shigeyoshi Iizuka, Kanagawa University
Sakae Yamamoto,Tokyo University of Science
- Report Outline :
- Original article
Appeared on Ergonomics of Human System Interaction, Vol. 14, No. 1, 1/8, 2012.
Generally in the Web communication, we depend on the great amount of information
received from vision. When sensational information other than vision is used, it is effectively works
as a complementary feeling. This research focuses on the use of variations in temperature to
represent information expressively. The mouse with thermal capabilities is a device that becomes
warmer (colder) at a user's palm when the user clicks “warm” (“cold”) photographic images on a
computer screen. Each image has an associated thermal value. In this paper, the result of an
experiment indicates that the thermal expression to mouse affects a user's impression of images.
Key Words: Thermal information, Thermal mouse, Warm sense, Cold sense, Pair comparisons
method.
- A Simple Power Spectral Analysis for Heart Rate Variability
- Publish Date : 2013/03/01 Vol.13
- Authors :
- Abbas Orand, Yutaka Tomita, Keio University
- Report Outline :
- Technical note
Appeared on Ergonomics of Human System Interaction, Vol. 13, No. 1, 15/16, 2011.
Keywords: Fourier transform of unevenly spaced time series, Heart rate variability, Regression analysis, Confidence interval
- Design and Development of a Myo-Electric Controlled Artificial Hand
- Publish Date : 2013/03/01 Vol.13
- Authors :
- Yasunari Hashimoto, Junichi Ushiba, Yutaka Tomita, Keio University
- Report Outline :
- Original article
Appeared on Ergonomics of Human System Interaction, Vol. 13, No. 1, 9/14, 2011.
Faculty of Science and Technology, Keio University provides an opportunity for junior-high-school students to give a chance to attend a
course of "Design and Development of a Myo-Electric Controlled Artificial Hand" as well as other scientific and technological courses. Junior-high-school students who enrolled the course study neurophysiology, electric circuits, computer programming that are the equivalent level of sophomore or junior classes in university. With adequate assistance of senior university students, junior-high-school students overcame the difficulties of the topic enthusiastically. We concluded that it has benefits for junior high school, and their students who have intellectual curiosity and interest in this field.
Keywords: Artificial hand, Myo-electric control, Junior-high-school students, Hot Soup Processor
- Estimating Membrane Potential in Human Motoneurons
using a Per-Stimulus Time Histogram
- Publish Date : 2010/03/01 Vol.10
- Authors :
- Yasunari Hashimoto, Junichi Ushiba, Yutaka Tomita, Keio University
- Report Outline :
- Original article
Appeared on Ergonomics of Human System Interaction, Vol. 10, No. 1, 16/22, 2007.
Although it is useful to learn how alpha motoneurons integrate motor and sensory inputs in humans to understand the motion control mechanism and to study the neuronal diseases, it was considered that the identification of after-hyperpolarization (AHP) is impossible in humans because it is unethical to record membrane potentials at the cell body in vivo. In this paper, we propose a novel method to estimate AHP based on peri-stimulus time histogram (PSTH) analysis. The response properties of PSTHs, where a stimulus is delivered at a fixed delay time after the previous discharge of a motor unit, provide the characteristics of the membrane potential at the cell body of motoneurons. We investigated the responses of 21 single motor units to electrical common peroneal nerve stimulation in the right tibialis anterior (TA) muscle of 5 healthy subjects. The stimulus was applied through a bipolar stimulating electrode placed distal to the neck of the fibula at an intensity of 83–93% of the motor threshold to only activate Ia afferents of the TA. We obtained 6 PSTHs with different delay times (5, 15, 25, 35, 45, and 55 ms) in a single recording session. To validate the estimation, we investigated the relationship between the mean interspike interval and the slope of the estimated AHP, and observed a significant inverse relationship (p < 0.02). We concluded that the relationship between the firing response and the delay of the stimulus represents the transition of the motoneuronal AHP.
Key words: After-hyperpolarization, Peri-stimulus time histogram, Tibialis anterior muscle, Motor unit
