Kageyu Noro

Determination of Counting Time in Visual Inspection

A series of experiments was conducted to clarify the relationship between the time required and visual process for counting dots projected onto a screen. The eye movement of the subject on each experimental trial was recorded by the electro-oculograph method and eye mark recorder. According to the experimental results, the subject used two information processes depending on the number of dots and symmetry of patterns. Both latency and movement time depend on the configuration of dots in the sample. An excess number of saccades is one of the causes for miscounting. A model for estimating counting time was built on the basis of the findings obtained. The time estimated by the model, if the maximum number of saccades does not exceed the number of dots on each sample, may be taken as optimum counting time.

Human Factors Which Have Helped Japanese Industrialization

Human factors research in Japan dates from the 1920s. Japanese human factors research has followed labor science approaches and systems approaches for improving man-machine systems. European influences are recognized in the former approaches, while American influences are noticeable in the latter. Since its foundation in 1964, the Japan Ergonomics Research Society has been working as the base for human factors studies and activities. The professional fields of the societys members are greatly different from those of the American counterparts. Activities related to the automobile and steel industries and to the Shinkansen Line are described as characteristic examples in the Japanese human factors field. The system capabilities and lifetime employment institution peculiar to Japan have made great contributions to these research activities. One of the major problems which faces Japanese human factors specialists is how to assign to humans and machines the jobs which call for intellectual and sensory functions.

Increasing Productivity in Computer Software Development by Environmental Modification

In this paper, we deal with the computer software development task which is completely new in the researches of human factors. In order to increase productivity in software development, environmental modification in a software office was carried out: At first, we proposed the procedure for environmental modification in software offices, by taking into consideration the processes involved in system design. An actual work environment was, then, modified by using this procedure. Finally, we obtained the guidelines on environmental modification in software offices.

Constructing an Industrial Inspection Model to Predict Operator's Performance

Since inspection is subordinated to production at the factory, the time and working conditions allowed for inspection frequently depend on the capacity of production machinery and the target production volume for the month. The time thus determined is not necessarily suited to maintain the required reliability and liable to exceed the limit of mans visual capability. For this reason, it is necessary to establish a procedure for working conditions and standard time using biological information and find standard time by the established procedure. This paper describes the procedure to establish working conditions and standard time from visual information.

Evaluation by Mental Stress of Paced and Self-Paced Conditions on Simple Repetitive Tasks in Design of Optimum Working Speed

Eight working speeds, conveyor-paced and self-paced, were established for a repetitive task with considerable difficulty in eye-hand coordination. The procedure for calculating pace allowances in this type of repetitive task was experimentally studied from the two angles of physiological and psychological functions of the subjects and quantative and qualitative variations of the task. The results obtained are as follows: (1) The maximum output speed under the self-paced condition was 125% of that when the subjects performed the task at their free pace. The quantative and qualitative performance of the subjects under the self-paced condition was better than that attained under the other conditions, but the physiological and psychological functions of the subjects lowered greatly 90 minutes after the start of the task. (2) When establishing the working speed for conveyor-paced operations, the basic time value calculated by the MTM procedure was satisfactorily used to set the standard speed per cycle. The time value obtained by the WF procedure, on the other hand, was not preferred in terms of both the performance and the physiological and psychological functions of the subjects.

Constructing a Search Model to Predict Percent Correct Counts for Each Sample

Drop in reliability of counting inspection is due to the miscounting of objects being inspected. A series of experimental runs was taken to determine the causes of this miscounting. In the experiment, the eye movements of the subject were measured with an eye camera. The analysis of the measured eye movements showed that there are two causes of miscounting: making a smaller number of eye movements than the number of objects to be counted and overlooking objects present in the field of peripheral vision. It was found that the former type of miscounting occurs during the counting process, one of the two human information processes, and that the latter occurs during the immediate apprehension process. A model to predict miscounts was constructed from the obtained findings.