Journal of The Japan Forest Engineering Society
Online ISSN : 2189-6658
Print ISSN : 1342-3134
ISSN-L : 1342-3134
Volume 12, Issue 3
Displaying 1-5 of 5 articles from this issue
Article
  • Xiao Dong PAN, Jun'ichi GOTOU, Biao GUO, Makoto YAMAMOTO
    Article type: Article
    1997 Volume 12 Issue 3 Pages 163-172
    Published: December 15, 1997
    Released on J-STAGE: April 03, 2017
    JOURNAL OPEN ACCESS
    On the projects of the arterial road, projectors have to take qualitative items and quantitative items into consideration, therefore it is difficult to decide an adequate route of road with the objectivity. In the case of the project with four proposed routes in north-eastern part of China, according to the chinese planning method, we offered three such supra-functional factors as economic index estimated by basic designing, technical index estimated by reconnaissance and difficulty at constructing and maintaining. Three factors consist of sixteen items. Five qualitative items were evaluated as fuzzy set from the answer of questionnaire. In order to include all items in consideration, we applied the fuzzy logic to the decision making of the route. Each fuzzy set consists of four such words as excellent, good, middle and bad. Applying analytic hierarchy process we calculated weights of each items within the factor and weights of each factors. The grade at the word of "excellent" under the fuzzy set were 0.219 (plan D), 0.397 (E), 0.192 (F), 0.203 (G). On the other hands, the grade at the word of "bad" were 0.590 (D), 0.264 (E), 0.599 (F), 0.461 (G). The evaluated value as the comprehensive criteria indicated that the plan E exceeded to other routes especially. The Chinese projectors also judged the plan E as the adequate route under their experiences. In conclusion, we prove that the applying fuzzy logic to the decision making of the arterial road is available and effective quantitatively.
    Download PDF (898K)
  • Myles MAC DONNCADHA, Masao SHISHIUCHI
    Article type: Article
    1997 Volume 12 Issue 3 Pages 173-182
    Published: December 15, 1997
    Released on J-STAGE: April 03, 2017
    JOURNAL OPEN ACCESS
    Because of the pressures of smaller harvesting areas, an increased thinning requirement and labor shortage a whole-tree harvesting system has evolved using a mobile tower yarder and roadside processor. Under analysis, this system is seen to display capital and labor utilization inefficiency due to the waiting time incurred by the processor. As measured in two studies in Toyoma-cho, Miyagi prefecture, this imbalance may result in a loss of \2500-3000 per hour at a haul distance of just 60 meters in a row thinning operation. Proposed here is the development of a hybrid machine, part processor, part tower yarder, controlled by a single operator. For practical viability the yarding tasks must be reallocated among the operator and chokerman using remote control and other technologies. If the capital cost of the hybrid machine is \25 million, or about 25% less than the existing two-machine system, then the savings per harvested cubic meter could be up to 26%. The new machine will show the greatest benefit over the existing system when operating at spans over 100 meters with a good landing space. Training and the downtime costs will be higher with this machine due to its increased complexity and the dependence on one machine to do two operations ; this should not be underestimated.
    Download PDF (618K)
  • Katsumi TOYOKAWA, Yozo YAMADA, Shinji HIROBE, Takumi UEMURA, Yuki IMAT ...
    Article type: Article
    1997 Volume 12 Issue 3 Pages 183-192
    Published: December 15, 1997
    Released on J-STAGE: April 03, 2017
    JOURNAL OPEN ACCESS
    The operation efficiency of a wheel grapple-bunk skidder is higher than that of the present winch skidder, the time for grappring the tree length log being 4.6% of total operation time. The work intensity level was light physiological loads, the average heart rate being 84 beats/min. The HRmax appears when skidder grapping the tree length log in looking the rear. The main objects of the field that were invisible to the front were cabin, bonnet, and exhaust pipe. The results that the solid angles for dozers and wheel are small in spite of the operators concentrating their fixations on them, are considered a serious problem. As the seat facing 17° to the right-rear, the operator can face easily just to the rear, looking at the tree length log in grapping and at the skidded logs in skidding with load. But, there was 55.8% of all operating time in operator's twisted body posture. The vibration on the seat in 3 directions were allowable below the "Fatigue-Decreased Proficiency Boundary" according to the ISO-proposal. When going back to the felling site and skidding with load, the noise level at the operator's ear is higher than noise limits at the frequencies of 1-4 kHz prescribed in "Japan Association of Industrial Health". These noise level of the equivalent continuous sound level is 80-93dB(A) over the limit of occupational noise level in "Occupational Safety and Health Regulation". Comparing the position of the levers and pedals with JIS-proposal, these are arranged at suitable positions. As the height of step being higher than the standard value proposed, operator access to and from cab with any discomfortable postures.
    Download PDF (816K)
  • Shigeki SASAKI, Tetsuhiko YOSHIMURA, Toshiaki YAMAMOTO, Kunihiko NUMAT ...
    Article type: Article
    1997 Volume 12 Issue 3 Pages 193-202
    Published: December 15, 1997
    Released on J-STAGE: April 03, 2017
    JOURNAL OPEN ACCESS
    It is important to think much of yarding direction, that is, uphill or downhill, especially when yarding using a tower yarder. Yarding direction is also related to the layout of forest roads. In this study, we applied a newly-developed tower yarder altered from a power shovel to the downhill yarding as well as the uphill yarding. We compared the productivity, work loads and trouble frequency between uphill yarding and downhill yarding and tested the performance of this yarder when applied to downhill yarding. As a result, the productivity of downhill yarding was 61.4% of that of uphill yarding. Trouble frequency of downhill yarding was also higher than that of uphill yarding. Moreover, in downhill yarding, setup and removal took more time and work load of carrying lines was much higher. The results showed that this tower yarder could be applied to downhill yarding although the productivity, trouble frequency and work loads were less advantageous compared with uphill yarding.
    Download PDF (869K)
Research and technical report
feedback
Top