• 제목/요약/키워드: quality indices

검색결과 864건 처리시간 0.026초

환경평가지표의 개발 (Environmental Assessment Index Development)

  • 최덕일;장준기;김명진;이재운
    • 환경영향평가
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    • 제1권1호
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    • pp.31-40
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    • 1992
  • As the environmental concerns in Korea have shifted gradually from the environmental pollutions to the quality of life (QOL) enhancement, it has become increasingly important to implement comprehensive assessment of environmental quality as possible. This is the major reason to develop Environmental Assessment Index. This study focuses on indices development of factors in Environmental Impact Statement Preparation Regulation. Environment in this regulation is composed of natural environment, life environment and socio-economic environment, and it is composed of 22 factors. EAI(Environmental Assessment Index)studied in this research is integrated by 16 factors. It will contribute to public participation in Environmental Impact Assessment process and environmental policy.

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Analysis of Generalized Impact Factors and the Indices of Journals

  • Abbas, Ash Mohammad
    • Journal of Information Processing Systems
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    • 제7권2호
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    • pp.341-354
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    • 2011
  • Analyzing the relationships among the parameters for quantifying the quality of research published in journals is a challenging task. In this paper, we analyze the relationships between the impact factor, h-index, and g-index of a journal. To keep our analysis simple and easy to understand, we consider a generalized version of the impact factor where there is no time window. In the absence of the time window, the impact factor converges to the number of citations received per paper. This is not only justified for the impact factor, it also simplifies the analysis of the h-index and g-index as well because addition of a time window in the form of years complicates the computation of indices too. We derive the expressions for the relationships among impact factor, h index, and g-index and validate them using a given set of publication-citation data.

공정능력지수 $C_p$에 대한 효율적인 가설검정 (Better Statistical Test for Process Capability Index $C_p$)

  • 조중재;임수덕
    • 품질경영학회지
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    • 제34권3호
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    • pp.66-72
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    • 2006
  • The process capability indices are widely used to measure the capability of the process to manufacture items within the specified tolerance. Most evaluations on process capability indices focus on point estimates, which may result in unreliable assessments of process performance. The index $C_p$ has been widely used in various industries to assess process performance. In this paper, we propose new testing procedure on assessing $C_p$ index for practitioners to use in determining whether a given process is capable. The provided approach is easy to use and the decision making is more reliable. Whether a process is clearly normal or nonnormal, our bootstrap testing procedure could be applied effectively without the complexity of calculation. A numerical result based on the proposed approach is illustrated.

송전용 자기애자의 수명 평가 연구 (A Study on Life Expectancy Forecast for Porcelain Insulators)

  • 이원교;최인혁;황갑철;최한열
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.462-463
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    • 2008
  • 36,000lbs porcelain insulators (D-1995, D-1997, D-2002) investigated mechanical and electrical qualities, which were installed in the Korea 154kV transmission lines. This paper assessed Weibull distribution function, quality index, and uniformity index to forecast the remaining life expectancies of insulators. Applying Weibull distribution function on year lapse change test, electro-mechanical failing load test, and HRB values confirmed a significant degree of correlation. Statistically calculating the life expectancy through quality indices for aging and new products and uniformity indices that are associated with uniformity of insulation materials revealed.

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불량률과 이치하는 공정능력 지수 $C_{pd}$ (A Process Capability Index $C_{pd}$ Consistent with the Proportion of Nonconforming Items)

  • 임태진;변시섭
    • 품질경영학회지
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    • 제28권2호
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    • pp.103-122
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    • 2000
  • Process capability indices (PCI) $C_p\;C_{pk},\;C_m,\;and\;C_{pmk}$ are widely used to evaluate the process performance. The PCI's have been evolved to consider the 'off targetness' more adequately. However, all of these indices are found to be inconsistent with the proportion of nonconforming items, in some cases. That is, the PCI for a process may result in higher value even when the proportion of defectives increases. For these reasons, we propose a new capability index, $c_{pd}$, which is consistent with the defect rate. The characteristics of the new PCI, $c_{pd}$ are investigated with respect to the existing PCI's. Some statistical properties of an estimator for $c_{pd}$ are also investigated by a Monte Carlo simulation. Sensitivity study under minor deviation from normality is also performed to show the robustness of $c_{pd}$. A good estimator for $c_{pd}$ is under study.

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창원지역 지하수 수질과 DRASTIC에 의한 지하수 오염취약성 평가

  • 김무진;함세영;정재열;장성;차용훈
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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    • pp.459-462
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    • 2004
  • This study assesses groundwater vulnerability to contaminants in 12 administrative districts of the city of Changwon, using DRASTIC technique. DRASTIC was originally applied to situations in which the contamination sources are at the ground surface, and the contaminants flow into the groundwater with infiltration of rainfall. However, groundwater contamination in urban areas can also be related to excessive pumping resulting in a lowering of the water level. The correlation coefficient between minimum DRASTIC indices and the degree of poor water quality for 10 districts is low as 0.40. The correlation coefficients between minimum DRASTIC indices and the groundwater discharge rate, and between minimum DRASTIC indices and well density per unit area are 0.70 and 0.87, respectively. Thus, to evaluate the potential of groundwater contamination in urban areas, it is necessary to consider other factors such as groundwater withdrawal rate and well density per unit area with ratings and weights as well as the existing six DRASTIC factors.

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도농통합지역의 녹지환경정비모델에 관한 연구II -천안의 녹지구조변화를 중심으로- (A Study on the Urban Fringe Landscape Environment Model- The Analysis of Change in Forest Structure of Chonan city-)

  • 심우경;이진희;김훈희
    • 한국조경학회지
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    • 제26권4호
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    • pp.105-112
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    • 1999
  • Landcover change is an important factor that changes structure and function of regional ecosystem. As the rise of concern on environment quality, many studies are trying to quantify and evaluate the landsacpe in recent days. In this study, using landscape indices with RS(Remote Sensing) and GIS(Geographic Information System) technology, spatio-temporal variations of areas and distribution of forest patches were examined in the Chonan from 1985 to 1996. Fragstats 2.0 was employed to analyze and compute 31 landscape indices from 52 landcover maps. A result of this study showed that area of forest and paddy decreased as a result of urban sprawl. Especially from 1993 to 1996, the change of land use progressed rapidly because of merging a city and a country in Chonan. The size of patch in forest had been smaller and irregular form, heterogeneity of size of forest patches within sub-basin increased, and variety of patch types around forest patches increased from 1985 to 1996.

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비정규분포하에서의 효과적 공정관리를 위한 기술체계동향 연구 (A Study of Technology Trends for Effective Process Control under Non-Normal Distribution)

  • 김종걸;엄상준;김영섭;고재규
    • 대한안전경영과학회:학술대회논문집
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    • 대한안전경영과학회 2008년도 추계학술대회
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    • pp.599-610
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    • 2008
  • It is an important and urgent issue to improve process capability in quality control. Process capability refers to the uniformity of the process. The variability in the process is a measure of the uniformity of output. A simple, quantitative way to express process capability, the degree of variability from target in specification is defined by process capability index(PCI). Almost process capability indices are defined under normal distribution. However, these indices can not be applied to the process of non-normal distribution including reliability. We investigate current research on the process of non-normal distribution, and advanced method and technology for developing more reliable and efficient PCI. Finally we suggest the perspective for future study.

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정량적 분석에 의한 전남바다목장의 생태계 기반 어업평가 (A study on the ecosystem-based fisheries assessment by quality analysis in Jeonnam marine ranching ecosystem)

  • 박희원;최광호;장창익;서영일;김희용
    • 수산해양기술연구
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    • 제49권4호
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    • pp.459-468
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    • 2013
  • In the application of the ecosystem-based fisheries assessment Jeonnam marine ranching ecosystem, two fisheries, funnel fishery and trap fishery, were selected as target fisheries. Black seabream, Acanthopagru schlegelii, rock bream, Sebastes inermis, gray mullet, Mugil cephalus, were selected as target species for the funnel fishery, and conger eel, Conger myriaster, was target species for the trap fishery. For assessing indicators of four management objectives, that is the maintenance of sustainability, biodiversity, habitat quality and socio-economic benefits, indicators were selected considering the availability of data, which were 5 indicators for sustainability, 3 indicators for biodiversity, 4 indicators for habitat, 2 indicators for socio-economic benefit. The Objective risk indices for sustainability and biodiversity of two fisheries were estimated at yellow zone, medium risk level. The objective risk indices for habitat and socio-economic benefit were estimated at green zone, safe level. The species risk indices (SRI) were estimated at yellow zone. The fishery risk indices (FRIs) were estimated at 1.143 and 1.400 for funnel net fishery and trap fishery, respectively. Finally the ecosystem risk index estimated at 1.184.

Assessment of Semen Quality among Workers Exposed to Heat Stress: A Cross-Sectional Study in a Steel Industry

  • Hamerezaee, Masoud;Dehghan, Somayeh F.;Golbabaei, Farideh;Fathi, Asad;Barzegar, Loghman;Heidarnejad, Naseh
    • Safety and Health at Work
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    • 제9권2호
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    • pp.232-235
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    • 2018
  • Background: This study was conducted to investigate the heat stress and semen quality among male workers in a steel industry in Iran and investigate the relationship between heat stress indices and semen parameters. Methods: The study was conducted on workers exposed (n = 30) and unexposed (n = 14) to heat in a steel industry. After obtaining a brief biography of the selected employees, scrotal temperature, oral temperature, and environmental parameters were measured, and their semen samples were analyzed according to the procedure recommended by the World Health Organization. The heat stress indices, including wet-bulb globe temperature (WBGT) and predicted heat strain (PHS), in their workplace were calculated according to environmental parameters (ISO 7243:1989 and 7933:2004, respectively). Results: Time-weighted averages of WBGT and PHS ($35.76^{\circ}C$ and 491.56 $w/m^2{\frac{w}{m^2}}$, respectively) for the exposed group were higher than threshold limit values. The mean difference of environmental, physiological, and semen parameters (exception: pH of semen), and also WBGT and PHS indices were statistically significant (p < 0.05) between the two groups. Mean semen parameters were in the normozoospermic range. WBGT and PHS indices showed significantly "negative" correlation with physiological parameters (scrotal and oral temperature) and most semen parameters (semen volume, sperm morphology, sperm motility, sperm count; p < 0.05); moreover, the correlation of WBGT with these parameters was stronger than PHS. Conclusion: Semen parameters of the studied workers exposed to heat were in the borderline level of normozoospermic range, and their semen parameters were significantly lower than controls. For better assessment of occupational environment concerning physiological and semen parameters in steel industries, WBGT can be a more useful index.