The Japanese Journal of Ergonomics
Online ISSN : 1884-2844
Print ISSN : 0549-4974
ISSN-L : 0549-4974
Volume 41, Issue 3
Displaying 1-7 of 7 articles from this issue
  • Osamu ICHIKIZAKI, Keisuke SHIDA, Toshiyuki MATSUMOTO, Takashi KANAZAWA
    2005 Volume 41 Issue 3 Pages 121-130
    Published: June 15, 2005
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    The problem of how to acquire operational sequences is occurring widely under the situation that workers are moving and operations are changing frequently by customer demands and product short lead-times. The objective of this paper is to clarify the effectiveness of the training method that is dividing training operational elements in some units. By taking a simple operational task as an experimental job which is to point 24 rectangles on the display, experiments are conducted in terms of quantity of operational elements for each training. By analysing the results from the point of comparing efficiency of time and loss of training, findings are obtained as follows; training all operational elements as one unit is ineffective, and divided operational elements training is effective in terms of efficiency and loss. In the case of divided training, it is suggested that elements of training operation must be selected by each situation; for example, 8 must be selected when aiming to increase time efficiency and 1 must be selected when aiming to decrease training loss. In addition, the acquiring methods are classified into all-acquiring method and part-acquiring method. Time and loss of training increase when an unsuitable acquiring method is selected.
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  • Takahiro TAMESUE, Shizuma YAMAGUCHI, Tetsuro SAEKI
    2005 Volume 41 Issue 3 Pages 131-136
    Published: June 15, 2005
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    This paper considers how the listening score of audio signal and psychological impression for speech audibility change taking into account an effect of the hearing loss due to aging or anything. Frequency filters simulating hearing loss due to aging or anything are first prepared. Psychological listening experiment is conducted, in which both the audio signal and the noise which passed through the above-mentioned filters are transmitted to subjects with normal hearing. In addition, using the observed data of experiment, the relationships between spectral distance and the listening score/psychological impression for speech audibility are considered. Next, by use of this relationships, prediction problems of the listening score and psychological impression for speech audibility are discussed. The predicted results are in good agreement with the observed values.
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  • Chizuru NAKAGAWA, Hiroaki SUZUKI
    2005 Volume 41 Issue 3 Pages 137-146
    Published: June 15, 2005
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    To investigate the effects of train vibrations on PC operation and on the users, a survey was carried out and related experiments were conducted. A poll of 114 on-boad PC users was undertaken to identify the limitations of present on-board conditions and to ascertain the needs of PC users. The results indicated that majority of subjects were not satisfied with the size or adjustability of the seat tables. Experiments based on the PC users' survey results were performed to ascertain the optimum working space for PC use on a moving train. The subjects evaluated various set conditions while performing tasks on a PC in a train simulator. Simultaneously, some autonomic responses such as heart rate, heart rate variability and respiration were measured. The results indicated the ideal lengths, positioning, and optimum adjustability range for seat tables. The importance of adequate table space between the PC and user was also confirmed.
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  • Kiminobu KODAMA
    2005 Volume 41 Issue 3 Pages 147-153
    Published: June 15, 2005
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    The study of calculation errors in the continuous addition task has been paid attention to only the single calculation operation, so far. However, to calculate as many as possible, subjects will try to skillfully make the subtask parallel. In this paper, the hypothesis that the failure in the synchronization of the subtasks in the parallel operation leads “in-stream” errors was proposed, and an experiment to verify it was carried out. The continuous addition task was imposed on subjects in the “masked” condition, where a device that masks the next calculation task was used, and in the “transparent” condition, where a device that removed the mask was used. As a result, in the transparent condition, the number of “in-stream” errors was more than in the masked condition. Moreover, the possibility of originating from cognitive difficulty was found, rather than some algorithms leading the calculation error. The necessity for introducing the viewpoint of the parallelism of the task and cognitive difficulty was suggested from these results.
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  • Ken HORII, Aoi MIURA, Shigeki UESAKA, Kentaro KOTANI
    2005 Volume 41 Issue 3 Pages 154-160
    Published: June 15, 2005
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    Visual inspection is still playing a major role in inspection process at production lines, and as a result of this human factor involvement, production decrease is often said to be caused by the fatigue of the inspectors and this physical fatigue of the workers itself imposes a serious issue. The visual fatigue mainly comes from lowering activities of the optical system of the central nerves caused by the monotonous workload of inspection. Ishikawa and Sasaki proposed a new visual inspection method paying attention to visual characteristics, and this method improved detection rate of defective outputs from production lines. This productivity improvement is thought to be brought about from a fact that horizontal eye movement gives less fatigue to the optical system. This paper describes a remarked physiological workload difference upon visual inspectors between horizontal and vertical eye movements by experiments of shifting fixations horizontally and vertically, and it is shown from the experiments that the visual inspection method that uses horizontal movement is far more effective.
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  • Shinri WATANABE, Atsuko IKEGAMI, Motohiro OHKURA
    2005 Volume 41 Issue 3 Pages 161-166
    Published: June 15, 2005
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
    The present study examines efficient input methods for data obtained from the CFSI (Cumulative Fatigue Symptoms Index) questionnaire. The data consist of 81 ‘_??_’ or ‘×’ (yes or no) marks per sheet, in which the number of ‘_??_’s is usually far fewer than the number of ‘×’s. The following three methods were evaluated: A) Subjects input ‘1’ or ‘2’ instead of ‘_??_’ or ‘×’ using a numerical keypad; B) Subjects input the question numbers marked with ‘_??_’ using a numerical keypad; C) Subjects click on the boxes next to the question numbers marked with ‘_??_’ using a mouse. The 43 subjects from age 20 to 24 years were divided into two groups: 18 subjects who could touch-type and 25 subjects who could not. Each subject was then asked to input 15 sheets of data using each of the three methods. The results are summarized as follows.
    1) A numerical keypad was superior as an input device to a mouse whether the subjects could touch-type or not.
    2) For both groups, the most efficient method of input changed from method B to method A as the number of ‘_??_’s to be entered increased. The turning point in the number of ‘_??_’s was 17 for touch-typists, and 15 for non-touch-typists.
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  • Comparison of the martin method
    Shin-ichi SUSATO
    2005 Volume 41 Issue 3 Pages 167-174
    Published: June 15, 2005
    Released on J-STAGE: March 15, 2010
    JOURNAL FREE ACCESS
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