• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.125-141
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• 2011

Melamine has raised international concerns for its catastrophic health effects from tainted infant formula. This report concerns the developmental validation of a sensitive HPLC/MS/MS and GC/MS methods about melamine and cyanuric acid in human urine and serum. Analytical detection ranges of LC/MS was from 0.2 to 5.0 ng/mL and 2.0 to 60.0 ng/mL about melamine and cyanuric acid, respectively. The limits of quantification and confirmation are 0.2 ng/mL for both analytes in human urine and serum by LC/MS/MS. The range of recovery was 91.6%, and 107.6% for cyanuric acid and melamine in urine, respectively. The range of precision coefficient variation was from 2.0%, to 11.8% for cyanuric acid and melamine in urine. The range of recovery was from 94.9%, to 119.0% about cyanuric acid and melamine in serum, respectively. The range of precision coefficient variation from was 3.7%, and 13.5% about cyanuric acid and melamine in serum. Analytical detection ranges of GC/MS were 5.0 to 100.0 ng/mL about melamine and cyanuric acid, respectively. The limits of quantification and confirmation are 5.0 ng/mL for both analytes in human urine and serum by GC/MS. The range of recovery was from 83.7%, to 114.5% for cyanuric acid and melamine in urine, respectively. The range of precision coefficient variation was 3.5%, and 10.7% for cyanuric acid and melamine in urine. The range of recovery was 94.4%, and 110.7% for cyanuric acid and melamine in serum, respectively. The range of precision coefficient variation from was 3.9%, and 13.8% for cyanuric acid and melamine in serum. Several changes were taken to optimize performance by this method.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.3
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• pp.311-321
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• 2020

In this study, coefficient of variation for the seismic load effect on the segment lining was calculated. The statistical characteristics of the soil property were analyzed for the probability characteristics of domestic soil. In order to calculate the coefficient of variation for the seismic load effect, the MCS technique was applied, and the closed-form equation was applied to calculate the seismic load effect. As a result of calculating the coefficient of variation, the coefficient of variation of the seismic load effect on the weathered soil was analyzed in the range of 0.06~0.15, and the coefficient of variation was judged to be used as basic data for designing the limit state of the shield tunnel on seismic condition.

• Journal of Korean Society on Water Environment
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• v.27 no.2
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• pp.228-234
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• 2011

The goal of water quality management on stream and watershed is to focus not on discharged loads management but on a water quality management. Discharged loads management is not goal of water quality management but way for perform with total maximum daily loads management. It is necessary to estimate the relation between non-point source with stromwater runoff (NPSSR) and water quality to select a watershed where it is required to manage NPSSR for water quality improvement. To evaluate the effects of NPSSR on stream's water quality, we compare the aspects of water quality in dry and wet seasons using flow duration curve analysis based on flow rate variation data by actual surveying. In this study we attempt to quantify the variation characteristic of water quality and estimate the Inflow characteristic of pollution source with water quality and flow rate monitoring on 10 watersheds. We try to estimate water quality and flow rate by regression analysis and try again regression analysis with each high and low water quality data more than estimations. An analysis of relation between water quality and flow rate of 10 watersheds shows that the water quality of the Nonsan and the Ganggyeong streams had been polluted by NPSSR pollutants. Other eight streams were important point source more than NPSSR. It is wide variation range of $BOD_5$ also high average concentration of $BOD_5$. We have to quantify water quality variation by cv1 in wet season and cv365 in dry season with comparing the estimate of high water quality and low water quality. This method can be used to indicator for water quality variation according to flow rate.

• Communications of the Korean Mathematical Society
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• v.11 no.4
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• pp.1117-1122
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• 1996

A class of nonlinear Markov processes on the real line is considered, and a functional central limit theorem is proved for the functions of bounded variation on the real line by identifying a broad subset of the range of the generator.

• Korean Management Science Review
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• v.11 no.1
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• pp.51-58
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• 1994

The purpose of this study is to extend the current sensitivity analysis of the transportation problem. In this paper we present a systematic method to obtain the variation range of supplies or demands by introducing a dummy column or dummy row. By using this approach we can deal with the case of fixed demands, and the unbalanced problem that the total demand is greater than the total supply.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.5
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• pp.391-397
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• 1984

The seasonal and portional variation in the composition of uronic acid of alginic acid from Eckionia cava was investigated. The sample was collected from the coast of Ieechun Illkwangmyun, Yangsangun, Kyungnam, Korea, in the period of January to December in 1982. In seasonal variation of the content of alginic acid, the range of variation was larger in the frond than in the stipe, It was the highest content in between February to April, and the lowest in between August to October, and the content was more in the stipe than in the frond. The uronic acid ratio(M/G ratio) was varied seasonaly in a relationship with the variation of the alginic acid content. The maximum M/G ratio appeared in the period of December to March and minimum May to August, and the average values of the M/G ratios in the periods were 3.08, 2.64 in the frond and 2.91, 1.39 in the stipe, respectively. Additively a year mean values were 3.22 in the frond and 2.18 in the stipe.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.8
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• pp.1376-1385
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• 2000

The phase characteristic of delay line in feedfarward linearizer has been changed due to variation of operating temperature. In this paper, design method of fixed phase control circuit of group delay line using adaptive vector control is derived. To maintain transfer characteristics of nominal operating temperature, the error correlated signals, which are changed adaptively due to changing of temperature, are added to main signals. The proposed method maintains transfer characteristics under 0.06dB of insertion loss and 0.36$^{\circ}$ of phase variation in case of 1-tone(880 MHz) and under 0.07 dB of insertion loss and 0.35$^{\circ}$ of phase variation in case of 2-tones(877 MHz, 882 MHz) for 10dB input power dynamic range and +/-10$^{\circ}$ phase variation respectively.

• Journal of Korean Society of Forest Science
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• v.98 no.5
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• pp.531-538
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• 2009

We used enzyme electrophoresis to evaluate genetic diversity in five populations of endemic ash, Fraxinus chiisanensis in Korea. Of 15 putative allozyme loci examined 26.7% were polymorphic and expected heterozygosity for the species was low (0.082). Within the range, population were highly differentiated ($F_{ST}$=0.356) and little genetic variation was explained by geography. The pattern of distribution of variation showed low genetic variation within populations and pronounced divergence among populations, which was consistent with the prediction for the effects of limited gene flow and local genetic erosion. Although the frequencies of male plants were dominant ranging from 79.3% to 89.4%, most mating events seems to be inevitable mating between relatives in small populations based on heterozygote deficiency of this species. Small effective population size and the limited dispersal contributed to the low rates of gene flow within as well as between populations.

• Fashion & Textile Research Journal
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• v.8 no.1
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• pp.64-70
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• 2006

The purpose of this study is to investigate the somatotype variation & satisfaction with the fit of ready-to-wear for overweight women. For this study, questionnaires were administered to 154 overweight women in Andong & Daegu areas. Employing a sample of 116 data were analyzed by using F-test. And 10 overweight women's brands were analyzed for sizing system of women's ready-to-wear. The results were as follows: In the satisfaction with the somatotype variation of overweight women, length items increased and girth items decreased with aging. At neck, bust, waist, hip and sleeve circumferences, satisfaction with the fit of ready-to-wear decreased with aging. Correlation for somatotype variation & satisfaction with the fit of ready-to-wear was significantly positive. And main sizing system of overweight women' s ready-to-wear brands was size 99 & 105 cm(bust)-90 cm (waist)-110 cm(hip), and its sizing intervals was almost existed in range of 5 cm-7 cm. There were various sizing systems in overweight women's ready-to-wear brands, and it raised a problem of consumer's dissatisfaction.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.4
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• pp.630-636
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• 2008

Monitoring the location of the shoreline and foreshore changes through the time and core tasks are carried out by coastal engineers for a wide range of research. With the advent of digital imaging technology, the shore-based video monitoring system provides many advantages than field surveys. This study presents the development and construction(installation) of video monitoring system to assist the study of coastal and shoreline dynamics and evolution, especially sandbar variation at the Nakdong river estuary. For the purpose of this study, at high building near the Dadea-po beach (St. 2) and Jinudo(island) (St. 1) foreshore region, where coastline variation is highly active, 5 video cameras installed; the coastline movement has monitored since Aug. 2007 using the systems. From the image results of video camera, the 'Spit' type sandbar appears at the foreshore region of Doyodeung and Dadea-po beach and measured the deposition process of Jinudo(island) foreshore region. As a result, the monitoring system using video-based technique built in this study would be able to identify changes in the area and width of shoreline and beach of Nakdong river estuary.