• Title/Summary/Keyword: Taguchi's methods

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Molecular Detection of Verotoxigenic Escherichia coli (VTEC) from Animal Feces for Screening VTEC-shedders

  • Kobayashi, Y.;Sato, M.;Taguchi, H.;Koike, S.;Nakatsuji, H.;Tanaka, K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.3
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    • pp.423-427
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    • 2004
  • Seventy-six animals including cattle, sheep, horses, 6 species of zoo animals were employed for collection of fresh feces in order to detect verotoxigenic Esherichia coli (VTEC) by safe, quick and sensitive PCR-based molecular methods. Bacterial cell disruption with bead-beating followed by bacterial DNA purification with hydroxyapatide chromatography and gel filtration allowed DNA preparation from animal feces with high recovery and purity. A mountain goat was firstly shown by PCR and sequencing to shed verotoxin 2 gene (vt2) that was used to generate vt2 probe and second primer set for nested PCR to attempt more sensitive detection. Most sensitive nested PCR revealed that 45% of tested cattle and 47% of tested zoo animals were VTEC-positive, while least sensitive normal PCR detected VTEC from none of these animals except a mountain goat. Moderately sensitive detection by PCR in combination with hybridization suggested that the VTEC density varied between the VTEC-positive cattle.

Development of a precision machining process for the outer cylinder of vacuum roll for film transfer (실험계획법을 통한 3.5인치 도광판의 두께 편차 최적화에 대한 연구)

  • Hyo-Eun Lee;Jong-Sun Kim
    • Design & Manufacturing
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    • v.18 no.2
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    • pp.41-50
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    • 2024
  • In this study, experimental design methods were used to derive optimal process conditions for improving the thickness uniformity of a 0.40 mm, 3.5 inch light guide panel. Process mapping and expert group analysis were used to identify factors that influence the thickness of injection molded products. The key factors identified were mold temperature, mold temperature, injection speed, packing pressure, packing time, clamp force, and flash time. Considering the resin manufacturer's recommended process conditions and the process conditions for similar light guide plates, a three-level range was selected for the identified influencing factors. L27 orthogonal array process conditions were generated using the Taguchi method. Injection molding was performed using these L27 orthogonal array to mold the 3.5 inch light guide plates. Thickness measurements were then taken, and the results were analyzed using the signal-to-noise ratio to maximize the CpK value, leading to the determination of the optimal process conditions. The thickness uniformity of the product was analyzed by applying the derived optimum process conditions. The results showed a 97.5% improvement in the Cpk value of 3.22 compared to the process conditions used for similar light guide plates.

No Increase in Breast Cancer Risk in Japanese Women Taking Oral Contraceptives: a Case-Control Study Investigating Reproductive, Menstrual and Familial Risk Factors for Breast Cancer

  • Ichida, Miho;Kataoka, Akemi;Tsushima, Ruriko;Taguchi, Tetsuya
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.9
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    • pp.3685-3690
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    • 2015
  • Background: Low-dose oral contraceptives (OC) were approved by the Japanese Ministry of Health, Labor and Welfare in 1999, yet despite their contraceptive and non-contraceptive health benefits, only 5% of the target population use them. Fear of increased cancer risk, particularly breast cancer, is one reason for this. Due to low OC uptake and low screening participation, a paucity of data is available on the risk of OC use and breast cancer in Japanese women. The present study investigated OC use and breast cancer risk, as well as menstrual, reproductive and family factors. Materials and Methods: This was a clinic-based case-control study of women aged 20-69yrs who had undergone breast screening between January 2007 and December 2013 in central Tokyo. In all, 28.8% of the participants had experience with OC use. Cases were 155 women with a pathologically confirmed diagnosis of breast cancer. Controls were the remaining 12,333 women. Results: Increased age was a significant risk factor for breast cancer (p<0.001). A lower risk was found in premenopausal women presently taking OC compared to never users (OR 0.45; 95% CI 0.22-0.90) after adjusting for age, parity and breast feeding, and a family history of breast cancer. Conclusions: Increased age rather than OC use had a greater effect on breast cancer risk. This risk may be decreased in premenopausal women with OC use, but further long-term prospective studies are necessary.

Design of a Concrete Mix Considering Curing Temperature and Delay Time in Concrete Placement (현장 콘크리트 타설시 양생온도와 대기시간을 고려한 배합설계 결정)

  • Moon, Sungwoo;Lee, Seong-Haeng;Choi, Hyun-Uk
    • Korean Journal of Construction Engineering and Management
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    • v.20 no.1
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    • pp.133-140
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    • 2019
  • The concrete mix should be designed and produced to reflect the specific site conditions during concrete placement. That is, the concrete mix design should be planned considering temperatures, work environments, pouring methods, etc. The objective of this research is to understand the external factors of curing temperature and delay time that influence concrete strengths during pouring work, and provide concrete mix design that can be most robust to the effects of external factors. The Taguchi's robust method is used in preparing the concrete mix design to achieve the research objective. In a case study, an indoor concrete test was performed to find the optimal combination of concrete mixes with external factors of curing temperature and delay time. Concrete test cylinders were made to test concrete strengths given different external factors. The study results showed that the optimal performance of concrete strength can be achieved by applying the robust method when preparing a concrete mix design.