Mental workload during VDT work with time pressure

Hiroyuki Izumi,Masanori Ohta,Masaharu Kumashiro 대한인간공학회 2007 대한인간공학회 학술대회논문집 Vol.- No.-

The aim of this study is to evaluate the time pressure effects induced by maximum time constraints on worker’s workload and performance. Time pressure is induced by time constraints. Almost workers should be performed their work under time pressure condition. So, time pressure is one of most important stressors in the workplace. In many case, time pressure was defined as the difference between the amount of available time and that of time required to solve a task. The time measured under free pace with task teaching only seems that it dose not equal to the ability of worker. The time measured under the condition of making the worker hurry by compulsion is needed to evaluate the effects of time pressure on worker’s workload and performance. In this study, the subjects required to finish each task within a shortest available time that varied depending on the task performance one task before.

A Database of Success Stories on " KAIZEN " Activities for Elderly Workers

Masaharu Kumashiro,Yuzo Takahashi,Hiroyuki Izumi,Koki Mikami,Tetsuya Hasegawa 대한인간공학회 1999 대한인간공학회 학술대회논문집 Vol.1999-2 No.-

A Database of Success Stories on " KAIZEN " Activities for Elderly Workers

Masaharu Kumashiro,Yuzo Takahashi,Hiroyuki Izumi,Koki Mikami,Tetsuya Hasegawa 대한인간공학회 2000 대한인간공학회 학술대회논문집 Vol.2000-1 No.-

Cumulative Probability of Prostate Cancer Detection Using the International Prostate Symptom Score in a Prostate-specific Antigen-based Population Screening Program in Japan

Kitagawa, Yasuhide,Urata, Satoko,Narimoto, Kazutaka,Nakagawa, Tomomi,Izumi, Kouji,Kadono, Yoshifumi,Konaka, Hiroyuki,Mizokami, Atsushi,Namiki, Mikio Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.17

The International Prostate Symptom Score (IPSS) is often used as an interview sheet for assessing lower urinary tract symptoms (LUTS) at the time of prostate-specific antigen (PSA) testing during population-based screening for prostate cancer. However, the relationship between prostate cancer detection and LUTS status remains controversial. To elucidate this relationship, the cumulative probability of prostate cancer detection using IPSS in biopsy samples from patients categorized by serum PSA levels was investigated. The clinical characteristics of prostate cancer detected using IPSS during screening were also investigated. A total of 1,739 men aged 54-75 years with elevated serum PSA levels who completed the IPSS questionnaire during the initial population screening in Kanazawa City, Japan and underwent systematic transrectal ultrasonography-guided prostate biopsy between 2000 and 2013 were enrolled in the present study. Of the 1,739 men, 544 (31.3%) were diagnosed with prostate cancer during the observation period. The probability of cancer detection at 3 years in the entire study population was 27.4% and 32.7% for men with $IPSS{\leq}7$ and those with $IPSS{\geq}8$, respectively; there was no statistically significant difference between groups. In men with serum PSA levels of 6.1 to 12.0ng/mL at initial screening, the probability of cancer detection was significantly higher in men with $IPSS{\leq}7$ than in those with $IPSS{\geq}8$. There were no significant differences in clinical characteristics between groups of patients stratified by IPSS. These findings indicate that the use of IPSS for LUTS status evaluation may be useful for prostate cancer detection in the limited range of serum PSA levels.

Output Voltage Increase of a Series Resonant DC-DC Converter

Osamu Matsuo,Hirofumi Matsuo,Yoichi Ishizuka,Koji Kuwahara,Hiroyuki Ota,Katsuhiro Izumi 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7

It has been considered that the series resonant converter takes the maximums of the output voltage in the resonant frequency. However, in practice, the series resonant converter takes the maximums of the output voltage that appears in the lower frequency band compared with the resonant frequency. We analyzed the output voltage characteristics of a series resonant converter circuit when the switching frequency is lower than the resonant frequency including the transformer magnetizing inductance from a transformer. As a result, it was confirmed that for the series resonant converter, the output voltage takes maximum at a lower frequency than the resonant frequency, and the output voltage is larger than the input voltage; that is, the converter has the output boost characteristics, and consequently, this converter can be used when the input voltage is varied widely. In addition, the switching frequency is clarified when the output voltage takes the maximum according to the load resistance and magnetizing inductance.

Deposition of Aerosols on Leaves in a Cool-temperate Larch Forest in Northern Hokkaido, Japan

Tatsuya, Fukazawa,Naoto, Murao,Hisashi, Sato,Masahiro, Takahashi,Masayuki, Akiyama,Takashi, Yamaguchi,Izumi, Noguchi,Hiroyuki, Takahashi,Chikara, Kozuka,Rei, Sakai,Kentaro, Takagi,Yasumi, Fujinuma,Nob Korean Society for Atmospheric Environment 2012 Asian Journal of Atmospheric Environment (AJAE) Vol.6 No.4

Aerosol concentrations at the CC-Lag site in the Teshio Experimental Forest increased from winter to spring and sometimes showed extremely high values associated with Kosa and/or forest-fire events. The range and mean of the mass concentrations of aerosol chemical species were as follows: total particulate mass, 1.2-29, 5.0; elemental carbon, 0.061-2.2, 0.43; organic carbon, 0.059-3.5, 0.79; and sulfate, 0.12-6.2, 1.8 ${\mu}g/m^3$. The total masses of the deposited particles on hybrid larch and on bamboo leaves were approximately 35 and 30 ${\mu}g/cm^2$, respectively. The amounts of soil particles on the leaves were 6 ${\mu}g/cm^2$ for the upper part of hybrid larch, 2 ${\mu}g/cm^2$ for the lower part of hybrid larch, and 1 ${\mu}g/cm^2$ for Sasa bamboo leaves. The amounts of deposited black carbon were 2.3 ${\mu}g/cm^2$ for the upper part of hybrid larch, 0.6 ${\mu}g/cm^2$ for the lower part of hybrid larch, and 0.2 ${\mu}g/cm^2$ for Sasa bamboo leaves. Half of the total deposited particular mass was attached on the hybrid larch; however, most of the total deposited mass was adhered on the Sasa bamboo leaves. Regardless of the species, there tend to be more deposited particles on the leaves in the upper part than in the lower part, with only a few meters height difference. Comparing the composition of the deposited particles to that of the atmospheric aerosols without any size cut, the fractions of water-soluble material sulfate and sea salt in the deposited aerosols were about one tenth and one hundredth lower than that in the aerosols, respectively. On the basis of the measured concentration and the deposited amount on leaves, the deposition velocity of black carbon was estimated to be approximately 0.5 cm/s.

Deposition of Aerosols on Leaves in a Cool-temperate Larch Forest in Northern Hokkaido, Japan

Fukazawa Tatsuya,Murao Naoto,Sato Hisashi,Takahashi Masahiro,Akiyama Masayuki,Yamaguchi Takashi,Noguchi Izumi,Takahashi Hiroyuki,Kozuka Chikara,Sakai Rei,Takagi Kentaro,Fujinuma Yasumi,Saigusa Nobuko 한국대기환경학회 2012 Asian Journal of Atmospheric Environment (AJAE) Vol.6 No.4

Aerosol concentrations at the CC-Lag site in the Teshio Experimental Forest increased from winter to spring and sometimes showed extremely high values associated with Kosa and/or forest-fire events. The range and mean of the mass concentrations of aerosol chemical species were as follows: total particulate mass, 1.2-29, 5.0; elemental carbon, 0.061-2.2, 0.43; organic carbon, 0.059-3.5, 0.79; and sulfate,0.12-6.2, 1.8 μg/m3. The total masses of the deposited particles on hybrid larch and on bamboo leaves were approximately 35 and 30 μg/cm2, respectively. The amounts of soil particles on the leaves were 6 μg/cm2 for the upper part of hybrid larch, 2μg/cm2 for the lower part of hybrid larch, and 1 μg/cm2 for Sasa bamboo leaves. The amounts of deposited black carbon were 2.3 μg/cm2 for the upper part of hybrid larch, 0.6 μg/cm2 for the lower part of hybrid larch, and 0.2 μg/cm2 for Sasa bamboo leaves. Half of the total deposited particular mass was attached on the hybrid larch; however, most of the total deposited mass was adhered on the Sasa bamboo leaves. Regardless of the species, there tend to be more deposited particles on the leaves in the upper part than in the lower part, with only a few meters height difference. Comparing the composition of the deposited particles to that of the atmospheric aerosols without any size cut, the fractions of water-soluble material sulfate and sea salt in the deposited aerosols were about one tenth and one hundredth lower than that in the aerosols, respectively. On the basis of the measured concentration and the deposited amount on leaves, the deposition velocity of black carbon was estimated to be approximately 0.5 cm/s. Aerosol concentrations at the CC-Lag site in the Teshio Experimental Forest increased from winter to spring and sometimes showed extremely high values associated with Kosa and/or forest-fire events. The range and mean of the mass concentrations of aerosol chemical species were as follows: total particulate mass, 1.2-29, 5.0; elemental carbon, 0.061-2.2, 0.43; organic carbon, 0.059-3.5, 0.79; and sulfate,0.12-6.2, 1.8 μg/m3. The total masses of the deposited particles on hybrid larch and on bamboo leaves were approximately 35 and 30 μg/cm2, respectively. The amounts of soil particles on the leaves were 6 μg/cm2 for the upper part of hybrid larch, 2μg/cm2 for the lower part of hybrid larch, and 1 μg/cm2 for Sasa bamboo leaves. The amounts of deposited black carbon were 2.3 μg/cm2 for the upper part of hybrid larch, 0.6 μg/cm2 for the lower part of hybrid larch, and 0.2 μg/cm2 for Sasa bamboo leaves. Half of the total deposited particular mass was attached on the hybrid larch; however, most of the total deposited mass was adhered on the Sasa bamboo leaves. Regardless of the species, there tend to be more deposited particles on the leaves in the upper part than in the lower part, with only a few meters height difference. Comparing the composition of the deposited particles to that of the atmospheric aerosols without any size cut, the fractions of water-soluble material sulfate and sea salt in the deposited aerosols were about one tenth and one hundredth lower than that in the aerosols, respectively. On the basis of the measured concentration and the deposited amount on leaves, the deposition velocity of black carbon was estimated to be approximately 0.5 cm/s.