The authors measured temperature and humidity inside three kinds of protective clothes for chain saw operators during simulated felling operations in order to obtain the basic data for developing protective clothes which are both physically and thermally comfortable. On thermal environment scales, protective trousers (C and D) were classified as slightly warm in the winter, warm in the spring, and hot to very hot in the summer. On the comfort scale, they were classified as comfortable in the winter, uncomfortable in the spring, and very uncomfortable in the summer. Therefore, it was found that wearing protective trousers was suitable in the winter in Japan, but not suitable for the other seasons from the viewpoint of thermal comfort. It was also found that although chaps (B) were colder than protective trousers in the winter, they provided more warmth than if no protective clothes had been worn. As for the wearing of protective clothes of this kind, the temperature and the humidity inside the cloth were not high in the spring, but very high in the summer. When such protective clothes are worn in the summer, it appears that heat and discomfort resulting from the high temperature and humidity could be ameliorated by loosening stop implements occasionally and improving the ventilation in the protective clothes. An investigation of worker burden showed no clear relation between heat/humidity environment and worker burden resulting from the wearing of these protective clothes.

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The endogenous development method has been proposed as one of the alternative method to develop more effectively for developing countries. Usually, primary industry, especially agriculture, is one of the main industries in developing countries. And they have been disposing a huge volume of biomass from agriculture. For this study, I chose the Malaysia palm oil industry as an example because it has been disposing a huge volume of oil palm biomass. This study was designed to verify that biomass utilization was a viable alternative method for the endogenous development and to determine the most effective combination of biomass utilization for the endogenous development. It showed this endogenous biomass utilization system could be a zero-emission eco-industry park because all biomass was utilized in an internal recycling system.

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Operators of mini forwarders have to endure various stresses, especially those resulting from whole-body vibration. To predict the fatigue of a mini forwarder driver caused by whole-body vibration, this study which consisted of field tests and laboratory tests, was conducted to find the bio-signals that can both explain the level of fatigue and be measured continually in field. At the first step, we selected typical working conditions during forwarding, and measured whole-body vibrations and noises during the forwarding under these conditions. Then, three subjects were exposed to reproduced vibrations and noises in the laboratory, while their bio-signals and subjective fatigue were measured. Our findings suggest that an EMG power spectrum derived from a sensor on the back and an HRV power spectrum of 0.1Hz frequency could be useful for predicting fatigue from whole-body vibrations.

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In forest work, mechanization is progressing, yet much pruning work is still performed by hand. This report provides a comparative study of the manual work and the mechanical work utilizing a remote-controlled machine to prune Chamaecyparis obtusa. Two forest workers pruned to height of 6 to 8m above the ground level. Each pruning, both manual and mechanical, was classified into work elements, and then the energy expenditure of each worker was estimated from the consumed time and the measured heart rates. It was found that the energy expenditure of the mechanical work was half that of the manual work. Analysis of the work elements indicates that pruning accounts for 75% of the total time consumed in manual work and observation of the situation accounts for 75% of the time consumed in the mechanical work. This difference in energy expenditure is connected with the higher load in the manual work. In terms of the number of trees which one worker can prune in a day, the years of forestry experience was a significant factor in the manual work, but it made almost no difference in the mechanical work. Highly experienced workers were more efficient in the manual work and less experienced workers were more higher efficient in the mechanical work. Therefore, it will be useful to adopt remote-controlled type pruning machines in order for new workers to do pruning work efficiently.

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The effectiveness of mask setting for point positioning in forests was studied. Elevation mask did not improve the positioning accuracy in forests, because the recommended elevation mask in a treeless area was not appropriate for positioning in forests with a large stand basal area. While usual SNR mask did not improve the positioning accuracy in forests, there was a significant relation between mean SNR and positioning accuracy. Although PDOP mask reduced the positioning success rate in forests, it had the greatest effect on reducing error in the successful cases. Multiple regression analysis was applied to find factors affecting the positioning accuracy. Elevation angles of four satellites significantly affected the positioning accuracy in a treeless area, and there was significance in PDOP and mean SNR inside forests. The maximum multiple correlation coefficient was 0.45. As a result of mask setting using the chosen variables, mean positioning error was reduced by 40% and 35% for a treeless area and a forest, respectively. In conclusion, the use of PDOP and mean SNR can enable us to control the positioning accuracy in forests.

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The purpose of this study is to investigate the possibility of using sawing residue as wood biomass energy and its effects on reducing domestic carbon dioxide emission when used as energy for wood seasoning. For this purpose we calculated the amount of sawing residue and energy needed during wood seasoning, and estimated the total emission of CO_2 that could be reduced by replacing fossil fuels with wood biomass. There are two types of sawing residue; one is bark and the other is wood. We measured the amount of bark with barker machine, and calculated the amount of wood from the difference between the weight of raw logs and processed lumber. The energy consumption of wood seasoning was derived by interviews with producers. As a result, we found the energy from sawing residue varies with water content as well as with the ratio of residue to raw logs. The amount of energy from wood biomass is enough for the whole seasoning process only when the woodchips that are usually used as pulp are used as fuel. The amount of reduction of CO_2 is 8.6 tons per 100 m^3 for such a case. For 26 million m^3 of raw logs, which was Japan's total saw log consumption in 2000, the possible reduction of carbon dioxide emission was estimated to be 2.3 million tons. This is about 3% of the 74 million tons which Japan pledged to reduce in the Kyoto Protocol.

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