• Title/Summary/Keyword: Minimum Quality

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A Heuristic Methodology for Fault Diagnosis using Statistical Patterns

  • Kwon, Young-il;Song, Suh-ill
    • Journal of Korean Society for Quality Management
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    • v.21 no.2
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    • pp.17-26
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    • 1993
  • Process fault diagnosis is a complicated matter because quality control problems can result from a variety of causes. These causes include problems with electrical components, mechanical components, human errors, job justification errors, and air conditioning influences. In order to make the system run smoothly with minimum delay, it is necessary to suggest heuristic remedies for the detected faults. Hence, this paper describes a heuristic methodology of fault diagnosis that is performed using statistical patterns generated by quality characteristics The proposed methodology is described briefly as follows: If a sample pattern generated by random variables is similar to the number of prototype patterns, the sample pattern may be matched by any prototype pattern among them to be resembled. This concept is based on the similarity between a sample pattern and the matched prototype pattern. The similarity is calculated as the weighted average of squared deviation, which is expressed as the difference between the relative values of standard normal distribution to be transformed by the observed values of quality characteristics in a sample pattern and the critical values of the corresponding ones in a matched prototype pattern.

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Efficiency Comparison of Signal-to-Noise Ratios through Monte Carlo Simulations (몬테칼로 씨뮬레이션을 통한 SN비의 효율성비교)

  • Lim, Yong Bin;Lee, Youngjo
    • Journal of Korean Society for Quality Management
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    • v.23 no.2
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    • pp.28-42
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    • 1995
  • For quality improvement, Taguchi emphasizes the reduction of variation of the quality characteristic, Taguchi has used the signal-to-noise ratios for achieving minimum dispersion of the quality characteristic with its location adjusted to some desired target value ${\tau}$ Lim(1994) proposes a reasonable SN ratio based on a linking relationship of the variance and mean through simple data analysis technique. In this paper we investigate the efficiency of those two SN ratios and variance stabilizing transformations through Monte Carlo Simulations.

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New Design of Cylindrical Cup Deep Drawing by Forming Analysis (원형컵 디프 드로잉의 성형해석에 의한 공정설계)

  • 정완진;김종호;류제구
    • Transactions of Materials Processing
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    • v.12 no.7
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    • pp.647-653
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    • 2003
  • A systematic approach for the process design in deep drawing is necessary to improve the quality of drawn cups. This study concentrates mainly on the influence of process design strategy on the product quality. Different types of process design were chosen from initial blank of 100mm in diameter to make final cup of 50mm in diameter. In order to make this cup, we used 2-stage deep drawing. Forming analyses are carried out to find out better design in terms of drawing force. It is proposed that the process design, in which maximum drawing forces during successive operations are equal, is a more desirable one. Through experiment, it is found that the proposed case shows equivalent values in terms of maximum drawing force during successive operations in real process and can achieve the best product quality in terms of dimensional accuracy. Thus, it is shown that proposed design is very effective in the improvement of quality in drawn cups and may be extended to deep drawing with more stages.

Framework on Soil Quality Indicator Selection and Assessment for the Sustainable Soil Management (지속가능한 토양환경 관리를 위한 토양질 지표의 선정과 평가체계)

  • Ok, Yong-Sik;Yang, Jae-E.;Park, Yong-Ha;Jung, Yeong-Sang;Yoo, Kyung-Yoal;Park, Chol-Soo
    • Journal of Environmental Policy
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    • v.4 no.1
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    • pp.93-111
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    • 2005
  • Defining soil quality in scopes and applications is one of the prerequisite for the sustainable management of soil environment to orient researches, strategies and policies. However, definition of soil quality is controversial depending upon a viewpoint of soil science or soil environment. Soil quality can be, irrespective of the disciplines, defined as the capacity of a soil to function within ecosystem boundaries to sustain biological productivity, maintain environmental quality and promote plant and animal health. Common to all of the soil quality concepts can be summarized as the capacity of soil to function effectively at present and in the future. The OECD includes soil quality as one of the agri-environment indicators. This article intends to i) summarize the current soil quality research, and ii) provide information on protocol of soil quality assessment. A framework for soil quality was divided into three steps: indicator selection as minimum data set (MDS), scoring of the selected indicators, and integration of scores into soil quality index. Korean government suggested possible physical and chemical indicators such as bulk density and organic matter for paddy and upland soils to OECD. The framework of soil quality assessment is not yet implemented in Korea. Countries such as USA, Canada and New Zealand have constructed the framework on soil quality assessment and developed a user-friendly version of soil quality assessment tools to evaluate the integrated effects of various soil management practices. The protocol provided in this review might help policymakers, scientists, and administrators improve awareness about soil quality and understand the way of soil environment management.

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The Determinants of Nursing Home Quality Indicators;A Multilevel Analysis (노인요양시설의 질 지표 결정요인에 관한 연구;다수준 분석)

  • Lee, Seung-Hee
    • Journal of Korean Academy of Nursing Administration
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    • v.12 no.3
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    • pp.473-481
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    • 2006
  • Purpose: The Purpose of this study was to examine the factors on the nursing home quality indicators. Methods: The subjects of this study were 377 residents living in the nursing home more than 30 bed. The subject's minimum length of residence is 3 months and age of the subject is year of 65 over. The data were analyzed using descriptive statistics, Pearson correlation and multilevel analysis. Results: The main result of the study were in following. First, the quality gap among nursing homes resulted from both institutional and person level factors. Second, the person level factors affecting the quality of nursing home included ALD. However institution level factors had no direct effect on dependent valuable. Third, the interaction effect between the institution and person level factors was found. The ADL have less effect on the quality of nursing homes doing more quality management than of nursing homes doing less. Forth, The effect of ADL was different according to the level of care planing and satisfaction survey. Conclusion: These results suggest that the determinants of nursing home quality indicators were ADL & quality management. This study will contribute to apply nusing home quality indicators in Korea.

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Ventilation standards in USA (미국의 환기 기준 동향)

  • Bae, Gwi-Nam
    • Proceedings of the SAREK Conference
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    • 2005.11a
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    • pp.116-118
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    • 2005
  • The ASHRAE first ventilation standard was established in 1973. This standard has been revised regularly, and recently the ventilation standard for residential building was issued separately. Two ASHRAE ventilation standards are introduced in this article.

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Outage Performance of Partial Relay Selection in Dual-Hop Decode-and-Forward Relaying Systems (듀얼 홉 디코딩 후 전달 중계 시스템에서 부분 중계 노드 선택 기법의 아웃티지 성능 연구)

  • Lee, In-Ho
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.11 no.3
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    • pp.40-47
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    • 2012
  • In dual-hop relaying systems, the conventional partial relay selection is based on the channel information only for the first hop. On the other hand, the efficient partial relay selection is based on the channel information for the hop with the minimum of the average channel powers for the first and second hops at each end-to-end link since the correlation coefficient between the end-to-end link quality and the link quality of the hop with the minimum of the average channel powers for the first and second hops is larger than that between the end-to-end link quality and the link quality of the other hop. In this paper, the outage probability of the conventional partial relay selection and the efficient partial relay selection in dual-hop decode-and-forward relaying systems is analyzed for non-identically distributed Rayleigh fading channels. Through numerical investigation, the outage performance of the efficient partial relay selection is compared with the outage performances of the conventional partial relay selection and the best relay selection based on all the channel information for the first and second hops.

Quality Characteristics of Sponge Cakes Containing Various Levels of Black Rice Flour (흑미가루 복합분의 이화학적 특성과 스펀지 케이크 품질특성)

  • Park, Young-Seo;Chang, Hak-Gil
    • Korean Journal of Food Science and Technology
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    • v.39 no.4
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    • pp.406-411
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    • 2007
  • In this study the replacement of wheat flour with 5 to 30% black rice flour was tested to examine its effect on sponge cake making properties. We evaluated the effects of the substitutions on various quality parameters of the cake, such as physicochemical and rheological properties, cake making quality, and texture characteristics. The water holding capacity value increased with increasing amounts of black rice flour, whereas the alkaline water retention capacity, Pelshenke value and sedimentation value decreased. The mixograph peak time and peak height, and the Rapid Visco Analyser peak, minimum, and final viscosity decreased with the addition of black rice flour. Increasing proportions of black rice flour resulted in reduced loaf volume. However, replacing 15% of the wheat flour with black rice flour did not significantly affect the characteristics of the sponge cake. The textural characteristics of the sponge cake crumb were influenced by the addition of black rice flour, and sponge cakes containing the additives showed increases in hardness, gummines, and chewiness.

Development of Environmental Control System for High-Quality Shiitake Mushroom (Lentinus edodes (Berk.) Sing.) Production

  • Kwon, Jin-Kyung;Kim, Seung-Hee;Jeon, Jong-Gil;Kang, Youn-Ku;Jang, Kab-Yeol
    • Journal of Biosystems Engineering
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    • v.43 no.4
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    • pp.342-351
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    • 2018
  • Purpose: Recently, an increasing number of farms have been cultivating shiitake mushrooms using a sawdust substrate and a cooler/heater. In this study, an attempt was made to develop an environmental control system using a heat pump for cultivating high-quality shiitake mushrooms. Methods: An environmental control system, consisting of an air-to-water type heat pump, a thermal storage tank, and a radiator in a variable opening chamber, was designed and fabricated. The system was also installed in the cultivation facility of a farm cultivating shiitake mushrooms so as to compare the proposed control system with a conventional environmental control system using a cooler-condensing unit and an electric hot water boiler. Results: The uniformity of the environment was analyzed through environment measurements taken at several positions inside the cultivation facility. It was determined that the developed environmental control system is able to control the variations in temperature and relative humidity to within 1% and 3%, respectively. In addition, a maximum temperature difference of $30^{\circ}C$ (maximum of $35^{\circ}C$, minimum of $5^{\circ}C$) and a maximum relative humidity difference of 30% (maximum of 90%, minimum of 60%) can be attained within 30 min inside the cultivation facility through the cooling of the heat pump and heating of the radiator in a variable opening chamber. Thus, the developed control system can be used to cultivate high-quality shiitake mushrooms more effectively than a conventional cooler and heater. Conclusions: In comparison with a conventional environmental control system, the developed system decreased the yield of ordinary mushrooms by 65%, and increased that of high-quality mushrooms by 217%. This corresponds to a 16% increase in gross farm income. Consequently, the developed system is expected to improve the income of shiitake mushroom cultivating farms.

Effects of Dipping Chicken Breast Meat Inoculated with Listeria monocytogenes in Lyophilized Scallion, Garlic, and Kiwi Extracts on Its Physicochemical Quality

  • Kim, Hye-Jin;Sujiwo, Joko;Kim, Hee-Jin;Jang, Aera
    • Food Science of Animal Resources
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    • v.39 no.3
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    • pp.418-429
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    • 2019
  • This study was conducted to evaluate the antioxidant and antimicrobial activities of lyophilized extracts of scallions (Allium fistulosum L., SLE), garlic (Allium sativum, GLE), and gold kiwi (Actinidia chinensis, GKE) and their effects on the quality of chicken breast meat inoculated with L. monocytogenes during storage for 9 days at $4^{\circ}C$. The lowest minimum inhibitory concentration and minimum bactericidal concentration (25 and 100 mg/mL, respectively) against L. monocytogenes were observed for SLE and GLE, respectively. GKE had the lowest half-maximal inhibitory concentration ($IC_{50}$) for 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging activity (5.06 mg/mL). The pH values of meat inoculated with L. monocytogenes and dipped in 1% SLE (LSLE), 1% GLE (LGLE), or 1% GKE (LGKE) were lower than that of the control on day 3 of storage (p<0.05). The initial population of L. monocytogenes in meat was 4.95-5.01 Log CFU/g. However, the population in the LSLE (5.73 Log CFU/g) was lower than that in the control (6.23 Log CFU/g) on day 5 (p<0.05). The volatile basic nitrogen value of the LSLE (19.90 mg/100 g) was lower than that of the control (24.38 mg/100 g) on day 7 (p<0.05). Moreover, treatment with SLE resulted in the maintenance of meat quality and reduced the population of L. monocytogenes on the meat. Thus, SLE may be used as an alternative natural and environmentally friendly sanitizer for reducing L. monocytogenes contamination in the chicken meat industry.