List of Dissertation Abstract (Dissertation Doctor)
NameSupervisor

Junya Watanabe

Atsumi Miyake

Title

Abstract

Research on the relationship between

In the manufacturing industry, the number of "drawn into aaging machinery with insufficient safetymachine" injury accidents and fatal accidents is still high andmeasures and occupational accidents

has stopped declining. Along with these, many industries inJapan are facing problems related to aging machinery andinfrastructure. In the manufacturing industry, many production
facilities were introduced as a result of capital investment for
production expansion during the period of high economicgrowth. In the subsequent period of flat growth, it is presumed
that the aging machines remained in position due to low
additional investment. According to the report entitled
Investigation and Analysis Project for Safety Measures inAging Production Equipment conducted by the Ministry ofHealth, Labour and Welfare, many aging machines are stillused. It also shows two occupational accident risks: aging
machines and insufficient protective measures are present. In
this study, the number of remaining aging machines withinsufficient protective measures was estimated by applying theWeibull reliability function. A correlation with the number of"drawn into a machine" occupational accidents which hasstopped declining was examined. In addition, aging machinesthat were manufactured in the past and have safety defects inview of the current international technical level, but have been

used for a long time were defined as "existing non-conformingmachines". The correlation between the estimated number ofremaining machines and the number of "drawn into a machine"
occupational accidents which has stopped declining was found.
Furthermore, when estimating the number of remaining
machines in the future from the estimated values, it was shownthat the rate of decline is slow, and no significant reduction in
occupational accidents can be expected assuming that there is acorrelation between the number of remaining machines and thenumber of fatal accidents in the future.
In addition, regarding occupational accidents caused bymachines, there are many examples of research that analyze
individual machines and individual occupational accidents.
Safety measures are also studied for individual cases. Whenconsidering safety measures for aging machines, it is importantto understand the characteristics of aging machines and thecharacteristics of occupational accidents caused by them.
However, there are no examples of analysis of thesecharacteristics.
Another purpose of this study is to examine the validity of thecharacteristics of aging machines regarding ''aging machines''and ''insufficient protection measures,'' which were shown as
occupational accident risks of aging machines according to theMinistry of Health, Labor and Welfare's ''report.'' To examinethe validity, the correspondence analysis was conducted, which
is a method of multivariate analysis, based on the crosstabulation data shown in the "report." The correspondence
analysis was also conducted to examine that appropriate
management methods such as risk assessment was not
sufficiently implemented as an issue in the management ofaging machines and occupational accidents caused by them. As
a problem from worker’s perspective, many occupational
accidents caused by aging machines occur among middle-aged
and elderly workers with short years of experience, but there
are differences in the causes of occupational accidents among
middle-aged and elderly workers compared to younger
workers. It was examined the validity of the possibility that
there was a difference between the education and training
provided to young workers with short experience and theeducation and training required of middle-aged and elderly
workers with short years of experience.
By applying multivariate analysis, it was shown that it waspossible to understand problems and confirm the validity of thecharacteristics of aging machines and the characteristics ofoccupational accidents caused by them.

Katsumi Tamada

Fumito Koike

Studies on the decline of grassland

Wetlands, grasslands, and farmlands are widely spread inbirds and habitat use in rural area byHokkaido. Not only the natural grasslands but also rural area isline transect census in Hokkaido

main habitat for grassland birds. Recently, some grassland birds
have been decreasing. SATOYAMA is one of priority area topromote conservation of biodiversity. Aims of this study is toaddress these two issues. To conserving the grassland birds, itis necessary to evaluate the population status, however, before
to compare the past and present avifauna, methodological study
about line transect census is necessary. Seasonal change in thenumber of individuals observed in line transect census wereconfirmed. Based on this result, I compared the avifauna
between 1970-1980s and 2002-2003. Drastic decline of
Yellow-breasted bunting was confirmed, and population of 4species might be decreased. I investigated habitat use ofgrassland birds in rural areas as an alternative habitat. EurasianSkylarks often use cultivated land, in other hand othergrassland birds often use weedy land. In rural areas, thepresence of weedy land might be important.