Sakae Yamamoto

The effects of VDT work on urinary excretion of catecholamines.

The mental components of 2 hours of VDT work for three age groups of volunteers were investigated using urinary excretions of noradrenaline and adrenaline. After the work of searching for target words, the noradrenaline excretion showed a tendency to decrease in the young group, a significant increase in the middle-aged and a tendency to increase in the elderly. There was no change in adrenaline excretion in any age group. The elderly had a slower work speed than the young or middle-aged. Noradrenaline excretion showed a significant increase after VDT work using small letters, no significant change with large letters and a tendency to decrease after hard-copy work. The adrenaline excretion, did not change. The work speed was slower during the VDT work with small letters than during the hard-copy work These data suggest that the elevated level of sympathetic nervous activity resulting from VDT work is not caused by the VDT itself but by the intensity of the VDT work, and suggest that the effect of the VDT ...

Fretting wear of stainless steel

Abstract Tests were carried out to study the effects of metal pairs, surface coatings and lubricants on the fretting wear of stainless steel under severe conditions. The results obtained were as follows. (1) Metal pairs good for fretting prevention were SUS 304 stainless steel-copper and SUS 304 stainless steel-silver. (2) The bonded solid film lubricants were effective for the initial period of the test but they were inadequate for long endurance. (3) A high viscosity oil did not protect the surface against fretting wear because of inadequate feeding. (4) A new solid lubricant SnI 2 for stainless steel was found. (5) Combinations of certain of these treatments resulted in very low wear rates which would be satisfactory in practical applications.

The effects of VDT work on the regulation of hemodynamics compared with aging

Urinary excretions of aldosterone, blood pressure, and heart rate were examined for three age groups of volunteers searching for target words on VDT for two hours. Aldosterone excretion did not change in the young and middle-aged groups, but increased in the elderly group. Blood pressure decreased midway through the work in the young group, and increased during the work in the middle-aged and elderly groups. Aldosterone excretion did not increase during hard-copy work or during VDT work with large letters, but increased during VDT work with small letters. During VDT work with both large and small letters, blood pressure increased. During hard-copy work, neither blood pressure nor heart rate changed, although blood pressure increased after the work. These data suggest that the sympathetic nervous activation represented by the increases in aldosterone excretion and blood pressure occurred definitively during VDT work with small letters under the conditions of this study. It is also suggested that this effect is enhanced by aging.

Disaster information collecting/providing service for local residents

It has been pointed out that when people lack the information needed in the event of a disaster, such as a disastrous earthquake, this could lead to social chaos, including unwanted rumors and outrages, or could disrupt rescue and relief activities. In Japan, by law in principle, self-help or mutual assistance is required immediately after a disaster, and local residents are required to make judgments for action on their own. Although disaster information systems are gradually being organized at the municipal level, actual emergency evacuation areas and essential information for local citizens are still not sufficiently ready for provision at this stage. In this study, we established and evaluated a service infrastructure with an autonomous wireless network, aiming at providing services to collect and deliver disaster information, which will be required by local residents.

VDT work affects urinary excretion of catecholamines in the young

Urinary excretions of catecholamines in young volunteers were examined during VDT work to evaluate whether VDT work affected sympathetic and adrenal function. The time course of work performance was also monitored. The excretion of catecholamines did not increase after the reference work with hard copy. Adrenaline excretion tended to increase after VDT work with large print, although the noradrenaline excretion did not change. After VDT work with small print, noradrenaline excretion increased significantly, and adrenaline excretion tended to increase. The work speed of the VDT group using small print in the early period was slower than that of the hard‐copy group or the VDT group using large print, but the difference diminished in the late period. Abrupt decreases in work speed, considered a result of exhaustion, did not appear in any group. These results suggest that VDT work may act as a stronger workload for the sympathoadrenal system than hard‐copy work, and it also suggests that VDT workload may be w...

Study of Haptics and Tactile Sense of the Direction of Movement

The operating tool is not mentioned for the case of a location cannot be directly confirmed visually. In above cases, by that people touch the operation tools at our fingertips, its direction can be confirmed. This paper was focused onto the touch, in other words, tactile and haptic. When the operator touches the operation device, for example, button, switch, etc. It is possible to understand of the direction of its movement of machine (equipment) from texture information of device obtained from the operation of the tactile device. From this, when performing multiple operations at the same time, and also the working conditions it is difficult to be confirmed an operation device in the eye, it is to aim to reduce operation errors. The experimental study was done. Tow impression are found as follows; the raise-get down and positive rotation – negative rotation. It has been proven that there is an association between directionality and textural sense of materials.

An improvement of disaster information system for local residents

It has been pointed out that when people lack the information needed in the event of a disaster, such as a disastrous earthquake, this could lead to social chaos, including unwanted rumors and outrages, or could disrupt rescue and relief activities. In our prior study, we established a service infrastructure with an autonomous wireless network, aiming at providing services to collect and deliver disaster information. The system consists of many small sub systems. An authorized user can register information using one of the sub systems that is working correctly. Asynchronously, they search another sub system via wireless network, and then they communicate to each other in order to exchange information they have. As a result, the information will be shared within a wide area by those processes like a bucket brigade. In this study, we improved and extended the system so that it may meet more nearly actually.

Measurement and evaluation in service engineering

This paper discusses how to advance the service engineering research. The service engineering is still established as study, and has not been completed. However, it dared to take up how to advance the service engineering research. As for the reason, the following three points are thought. First of all, the methodology of an original service engineering cannot establish it yet. The secondly, researchers involved in the service engineering have taken an active part to the research in various fields. Thirdly, the service engineering is researched therefore based on each ones current knowledge. It has been thought that it is necessary to devise a method that manages to be unified. Of course, what respect you should note while thinking about the system of the service engineering now is described. Especially, it is thought that the finding of a deeply related field to the Ergonomics is needed in the service engineering.

A Development of Information System for Disaster Victims with Autonomous Wireless Network

In times of huge disaster such as earthquake, information needs increase among victims and rescuers. Social ferment rises within afflicted area and the damage is spread, if the needs of information are not satisfied. In this research we developed an information system for disaster victims as a distributed autonomous system using a wireless network. This system consists of many sub systems. These sub systems are robust for collecting disaster information because they are small and simple. An authorized user can register information using one of the sub systems that is working correctly. Asynchronously, they search another sub system via wireless network, and then they communicate to each other in order to exchange information they have. As a result, the information will be shared within a wide area by those processes like a bucket brigade.

A Study on Effective Tactile Feeling of Control Panels for Electrical Appliances

This study focuses on the fact that tactile factors, compared to visual factors, have not been effectively applied to enhance the usability of control panels. It also evaluates the effectiveness of allocating a rough/smooth feeling to the surface of each button in a control panel according to its operational function. The first experiment reveals relationships between some of the impressions concerning the operation of electrical appliances and the rough/smooth feeling when touching the surface of buttons. Moreover, it provides specific information on what degree of roughness/smoothness should be applied to what types of functional buttons. The second experiment demonstrates that the usability of control panels can be enhanced by providing a rough/smooth feeling to each button, considering suitability with respect to operation impressions. In addition, results indicate that users may feel discomfort when the rough/smooth feeling does not correspond to operation impressions.