• Journal of Korean Society of Rural Planning
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• v.26 no.4
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• pp.53-65
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• 2020

This study aimed to provide a basic information for managing the water quality of national and regional 1st rivers in Gyeongnam by analyzing the emerging hot spot patterns in BOD, T-P, and TOC, and by grouping the changing trends into clusters. The emerging hot spot analysis for each water quality item was implemented in ArcGIS Desktop with monthly water quality data from 96 water environmental monitoring stations in Gyeongnam, and then four patterns of water quality change were classified by the K-mean cluster analysis. As for BOD, persistent cold spot pattern covered about 42.9% of target rivers, and T-P concentration tended to be low or be getting lower at over 70% of target rivers. While, for TOC, about 70% of target rivers resulted in oscillating hot spots. In addition, the cluster analysis showed that the downstream of Nakdong river had the top priority in terms of water quality management because of the increasing concentration for all the three water quality.

• Asian Journal of Atmospheric Environment
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• v.1 no.1
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• pp.9-13
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• 2007

Various aspects of the air quality problems caused by ambient particles in and around the city of Seoul are discussed. First, the trend of the air quality in Seoul over time is investigated along with the types and quantities of energy consumption in Seoul. It was found that the general air quality in Seoul has improved over the last twenty years because of a change in the primary fuel used in Korea. However, the visibility in Seoul, a representation of the ambient particle concentration, is still worse than in other cities in Korea. In the air around Seoul, secondary particle generation might be as important as particles directly emitted from within the city or transported from outside.

• Journal of the korean Society of Automotive Engineers
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• v.26 no.1
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• pp.76-82
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• 2004

In this paper, the trend of quality management system that suppliers in the automotive industry are adopting, the classification system of suppliers and car manufacturers requirements for quality are described. Due to the complexity of the requirements for quality, the introduction of an active quality management system which can meet all conditions is a difficult task. Thus, to cope with this difficulty, this paper shows the optimal requirements that suppliers have to consider when they are introducing quality management system and the discriminated strategies to assure parts quality by supplier model.

• Journal of Korean Society for Quality Management
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• v.9 no.2
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• pp.26-30
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• 1981

A typical industrial data - monitoring scheme often requires trend detection Trend detection can be accomplished in many ways. Common statistical methods are the sign test, the run test, and the trend test. Graphical methods include various smoothing schemes and the cusum. The cusum has established itself as an efficient method of detecting changes in the mean level of a process being monitored. The cusum requires a "target value" with which the raw data are compared. At production start - up it is often difficult to designate the target value. This paper offers a means of initiating the cusum technique without a target value.

• Journal of the Korean Data and Information Science Society
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• v.19 no.4
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• pp.1019-1026
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• 2008

The goal of this paper is to analysis the trend of stream quality about the upstream, middle stream and high areas of Nakdong River measurement points from January 1998 to December 2006. and to suggest some policy alternatives in Nakdong river. It used the three different monthly time series data such as BOD (biochemical oxygen demand), TN (Total Nitrogen) and TP(Total Phosphorus), of the three of Nakdong River measurement points. BOD, TN and TP data are analyzed with the LOWESS(Locally Weighted Scatter plot Smoother) nonparametric method.

• Korean Journal of Community Nutrition
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• v.27 no.3
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• pp.223-244
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• 2022

Objectives: This study was designed to investigate the relationship between metabolic risk factors, Index of Nutrition Quality, and the dietary quality index score of Korean adults. Methods: The subjects were 18,652 Korean adults aged 19 years or older (7,899 males, 10,753 females) who participated in the 2016-2019 Korea National Health and Nutrition Examination Survey. Subjects were divided into normal, pre-metabolic syndrome, and metabolic syndrome (MetS) groups according to the number of their metabolic risk factors. Data were analyzed using the SPSS program. Results: About 44.7% of men in the MetS group were at least college graduates (P < 0.001), whereas 52.0% of women in the MetS group were middle school graduates or lower (P < 0.001). The frequency of fruit and dairy products intake tended to decrease as the number of metabolic risk factors increased in both men and women (P for trend < 0.001). As the number of metabolic risk factors decreased, the frequency of grain intake tended to decrease in men (P for trend < 0.001) while the frequency of intake of red meat (P for trend = 0.001), poultry (P for trend < 0.001), and eggs (P for trend < 0.001) decreased in women. The total scores of Diet Quality Index-International (DQI-I) (men P < 0.001, women P < 0.01) and Korean Healthy Eating Index (KHEI) (men and women P < 0.001) were significantly lower in the MetS group compared to the other groups, and the total score of DQI-I and KHEI tended to decrease as the number of metabolic risk factors increased. Conclusions: Dietary quality evaluation using various indices can provide more information on the dietary problems related to metabolic risk factors. Nutrients and foods that have been confirmed to be related to metabolic risk factors can be used to develop dietary guidelines for the nutritional management of metabolic diseases.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.1
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• pp.101-119
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• 2018

In this study, we analyzed long-term measurements and air quality simulation results of four criteria air pollutants ($PM_{10}$, $O_3$, $NO_2$, and $SO_2$) for 10 years, from 2006 to 2015, with emphasis on trends of annual variabilities. With the observation data, we conducted spatial interpolation using the Kriging method to estimate spatial distribution of pollutant concentrations. We also performed air quality simulations using the CMAQ model to consider the nonlinearity of the secondary air pollutants such as $O_3$ and the influence of long-range transport. In addition, these simulations are used to deduce the effect of long-term meteorological variations on trends of air quality changes because we fixed the emissions inventory while changing meteorological inputs. The nation-wide inter-annual variability of modeled $PM_{10}$ concentrations was $-0.11{\mu}g/m^3/yr$, while that of observed concentrations was $-0.84{\mu}g/m^3/yr$. For the Seoul Metropolitan Area, the inter-annual variability of observed $PM_{10}$ concentrations was $-1.64{\mu}g/m^3/yr$ that is two times rapid improvement compared to other regions. On the other hand, the inter-annual variability of observed $O_3$ concentrations is 0.62 ppb/yr which is larger than the simulated result of 0.13 ppb/yr. Magnitudes of differences between the modeled and observed inter-annual variabilities indicated that decreasing trend of $PM_{10}$ and increasing trend of $O_3$ are more influenced by emissions and oxidation states than meteorological conditions. We also found similar patterns in $NO_2$. However, $NO_2$ trends showed greater regional and seasonal differences than other pollutants. The analytic approach used in this study can be applicable to estimate changes in factors determining air quality such as emissions, weather, and surrounding conditions over a long term. Then analysis results can be used as important data for air quality management planning and evaluation of the chronic impact of air quality.

• Journal of Korean Society for Quality Management
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• v.28 no.2
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• pp.252-263
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• 2000

The purport of quality assurance audit and its procedures as specified in ISO 9000 have been reviewed. The principles and techniques for interview, documentation of the results and quality trend analysis were discussed. The practical techniques for the performance of quality audit for measuring the effectiveness of quality management systems were suggested.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.616-618
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• 2000

This paper describes the recent research and technical trend of power cable system. Compact sizing with long length and large capacity is the main trend of the power cable. From the manufacturing process to the monitoring of the underground power line, various new techniques are being developed for reliability and high quality such as in-line monitoring system, triple common extrusion, PD measurement system, new type completion test, etc.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.94-96
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• 2003

Since 1995, MOCT(Ministry of Construction and Transportation) and KOWACO(Korea Water Resources Corporation) have established the National Groundwater Monitoring Network in South Korea and also MOE(Ministry of Environment) has operated Groundwater Quality Monitoring network. Until 2001, 202 monitoring stations by MOCT and 780 monitoring wells by MOE have been constructed, measured groundwater level and analyzed water samples. Groundwater quality analysis has been conducted two times a year during last 6 years for all monitoring wells. The quality data has about 15 components including pH, COD, Count of Coliform group, and etc.. Trend analysis has been peformed for 6 components(Coliform, pH, COD, NO$_3$-N, Cl and EC) of water quality which are analyzed more than 7 times for total monitoring wells. Two test methods have been used ; Sen's test and Mann-Kendall test. These trend tests have been done at the 0.05 significance level. By the result of Sen's test, Count of Coliform group has either upward or downward trends at 4.3 percent of the monitoring points. pH does at 5.6 percent, COD does at 8.6 percent, Nitrate-Nitrogen does at 13.2 percent, Chloride does at 13.4 percent, and. EC does at 11.6 percent of the monitoring points. The exact causes of the groundwater quality trends are difficult to specify. Notable downward trends in nitrate at many monitoring points may be the result of reduction on some contamination sources. Potential causes include diminished agricultural areas, improvements in sewage treatment and a decrease in atmospheric deposition. Increase in chloride at many monitoring points may be the result of increased non-point source pollution such as road salting and runoff from sprawling paved developments and suburbs.