• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.1
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• pp.43-49
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• 2007

The methods of physical oceanographic surveys to examine the effect of thermal discharge from nuclear power plants in Korea have been reviewed and a standard guide to the survey is proposed. It is desirable that in situ observation and numerical thermal diffusion modeling are conducted simultaneously to describe the variation in temperature distribution affected by thermal discharge from a power plant because any observation or numerical modeling alone has limits to do so quantitatively. It is suggested that the field observation must be based on the concept of heat budget modeling considering all artificial and natural heat sources/sinks around the power plant. Any results from numerical modeling must reach to a certain statistical significance level to use for a standard temperature distribution. In addition, the development of standard numerical codes is proposed to improve the problems shown in the past numerical circulation and diffusion modelling.

• Journal of Radiation Industry
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• v.18 no.1
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• pp.15-21
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• 2024

The Non-Proliferation Treaty (NPT) is the basis of global efforts to prevent the spread of nuclear weapons. In Republic of Korea, safety measures are integrated with NPT approval through agreements with the International Atomic Energy Agency (IAEA) and the Safeguards Agreement. In contrast, Democratic People's Republic of Korea (DPRK), initially an NPT member, withdrew, refusing IAEA nuclear inspections. This inhibits the precise management of DPRK's nuclear facilities and limits access to related information. The Korean Peninsula, politically divided, sees DPRK in control of nuclear weapons. Although the IAEA periodically evaluates DPRK's nuclear facilities, there's a research gap in contamination and site management with nuclear activities. Recognizing the presence or absence of such activities is crucial for peaceful nuclear endeavors. This proposal suggests the number and locations for environmental sample collection using the Visual Sample Plan (VSP) software for nuclear activity analysis. VSP software is sample collection locations and quantities through statistical tests on collected data, ensuring reliability for decision-making. The proposal identifies sites and facilities for nuclear activity analysis based on IAEA safety reports, utilizing the software's embedded methods. Suggested sampling locations for undisclosed nuclear activities employ VSP's embedded techniques, including 'Show that at least some high % of the sampling area is acceptable' to confirm contamination and 'Estimate the Mean' to evaluate the average contamination level.

• Physical Therapy Rehabilitation Science
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• v.13 no.2
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• pp.179-186
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• 2024

Objective: This study aims to assess the reliability and validity of the new hand-held spirometer as a potential substitute for traditional pulmonary function testing (PFT) devices. Design: Cross-sectional study. Methods: In this study, thirty healthy adults underwent spirometry using both the new hand-held spirometer and the MIR spirometer, which is a standard PFT device. Parameters including peak expiratory flow (PEF), forced expiratory volume in one second (FEV₁), and forced vital capacity (FVC) were measured and analyzed for validity and reliability. Inter-rater reliability and validity were evaluated through 95% limits of agreement (LOA) and intraclass correlation coefficients (ICC). Statistical analyses, including the Bland-Altman plots and the ICC, were utilized to assess agreement between the two devices. Results: The new hand-held spirometer exhibited a good agreement with intra-class coefficient (ICC [2,1]) ranging 0.762 to 0.956 and 95% LOA of -1.94 to 1.80 when compared with MIR. The test-retest reliability of the hand-held spirometer analyzed using - ICC [2,1] demonstrated a good level of consistency (ICC [2,1] =0.849-0.934). Conclusions: In conclusion, the study aimed to assess the potential of the new hand-held spirometer as a viable alternative to traditional PFT devices, with a specific focus on its reliability and validity in spirometric measurements. The new hand-held spirometer exhibited good test-retest reliability across all measured variables, suggesting its potential as a valid and reliable tool for simultaneous PFT measurements.

• Physical Therapy Rehabilitation Science
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• v.13 no.2
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• pp.143-151
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• 2024

Objective: This study aims to assess the test-retest reproducibility of the Short Form Berg Balance Scale (SF-BBS) and the Short Form Postural Assessment Scale for Stroke (SF-PASS) among chronic stroke survivors, focusing on their reliability for consistent measurements over time. Design: A cross-sectional study design Methods: Thirty chronic stroke survivors participated in this study, undergoing evaluations with SF-BBS and SF-PASS scales at two different points, separated by a seven-day interval. The analysis focused on test-retest reliability, employing statistical measures such as the Intra-Class Coefficient (ICC_2,1), Standard Error of Measurement (SEM), Minimal Detectable Change (MDC), and MDC%, the Bland-Altman plot to assess the limits of agreement and the extent of random measurement error. Results: The study found notable test-retest reproducibility for both SF-BBS and SF-PASS, with ICC values demonstrating strong reliability (0.932 to 0.941, with a confidence interval of 0.889 to 0.973). SEM values for SF-BBS and SF-PASS were reported as 1.34 and 0.61, respectively, indicating low measurement error. MDC values of 3.71 for SF-BBS and 1.69 for SF-PASS suggest that the scales have an acceptable level of sensitivity to change, with reliability metrics falling below 20% of the maximum possible score. Conclusions: The findings suggest that both SF-BBS and SF-PASS exhibit high intra-class correlation coefficients, indicating strong test-retest reliability. The SEM and MDC values further support the scales' reproducibility and reliability as tools for evaluating mobility and dynamic balance in chronic stroke survivors. Therefore, these scales are recommended for clinical use in this population, providing reliable measures for assessing progress in rehabilitation.

• Journal of the korean academy of Pediatric Dentistry
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• v.51 no.3
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• pp.220-228
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• 2024

In clinical pediatric dentistry, a base material with optical properties, including transparency, that can mask the color of the material used for root canal-filling is preferred. This study aimed to examine the optical properties of various base materials by thickness. The disk-shaped specimens were photopolymerized and fabricated using Ionosit (IN), TheraCal LC (TL), TheraCal PT (PT), and A2 shade of Filtek^TM Supreme Flowable Restorative (FZ), Fuji II LC (FL), and Ketac^TM Fil (KF) with 1 and 2 mm thickness. The color parameters of these specimens were measured using a spectrophotometer on a black and white background and were measured using the same method on a mold containing Vitapex^® and gutta-percha. The translucency parameter (TP) and color difference were calculated for each group. The Kruskal-Wallis and Bonferroni tests were used in the statistical analyses. The TP decreased when the thickness was 2 mm compared with 1 mm. The TP values of TL and PT were the lowest at all thicknesses. The TP values of 2 mm thickness in all molds filled with Vitapex^® and gutta-percha were the lowest for TL, PT, KF, and IN. In TL and PT, the color difference before and after the application of the canal-filling material was the smallest, regardless of material thickness. Within the limits of this in vitro study, TL, PT, KF, and IN demonstrated better masking of the color of canal-filling material.

• Magazine of the Korea Concrete Institute
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• v.10 no.6
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• pp.149-159
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• 1998

The reasonable prediction of time-dependent deformation of prestressed concrete(PSC) box girder bridges is very important for accurate construction as well as good serviceability. The long-term behavior is mostly influenced by the probabilistic characteristic of creep and shrinkage. This paper presents a method of statistical analysis and sensitivity analysis of creep and shrinkage effects in PSC box been taken into account - model uncertainty, parameter variation and environmental condition. The statistical and sensitivity analyses are performed by using the numerical simulation of Latin Hypercube sampling. For each sample, the time-dependent structural analysis is performed to produce response data, which are then statistically analyzed. The probabilistic prediction of the confidence limits on long-term effects of creep and shrinkage is then expressed. Three measure are examined to quantify the sensitivity of the outputs of each of the input variables. These are rank correlation coefficient(RCC), partical rank correlation coefficient(PRCC) and standardiozed rank regression coefficient(SRRC) computed on the ranks of the observations. Three creep and shrinkage models - i. e., ACI model. CEB-FIP model and the model in Korea Highway Bridge Specification - are studied. The creep model uncertainy factor and the relative humidity appear to be the most dominant factors with regard to the model output uncertainty.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.529-538
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• 1995

It has been believed that the increased release of free oxygen radicals ($O_2^-,H_2O_2$, and $OH^-$) might be a factor in the pathogenesis of periodontal diseases. Antioxidant enzymes such as glutathione peroxidase(GSH-PX) and catalase can protect the tissue damage from the $H_2O_2$. In order to investigate the GSH-PX and catalase activity in the blood plasma and red blood cells(RBCs) of the patients with periodontitis, 19 patients who had good general health, attachment loss more than 6 mm and bone loss were selected as periodontitis group, 7 patients who had severely inflamed gingiva were selected as gingivitis group, and 15 volunteers with good general and periodontal health were selected as normal group. 17 of 26 patients were performed scaling and root planing to reduce the gingival inflammation for gingivitis and periodontitis groups, and were selected as posttreatment group. After blood plasma and RBCs were collected and separated 1 ml of peripheral blood from each subject, GSH-PX activity in blood plasma and RBCs was measured by the same method that Stefan et al. did, and catalase activity in RBCs was measured by the same method that Beers et al. did. The difference of GSH-PX and catalase activity between normal, gingivitis, and periodontitis groups was statistically analyzed by ANOVA with SPSS/PC+ program, and the difference between pretreatment and posttreatment groups was analyzed by Student t-test. The results were as follows : 1. GSH-PX activity in blood plasma was significantly lower in the gingivitis group($0.8683{\pm}0.0658$), periodontitis group($0.7130{\pm}0.1333$) than in the normal group($1.0241{\pm}0.0801$)(p<0.05), and GSH-PX activity in RBCs was significantly lower in the gingivitis groupt. $0.8156{\pm}0.1167$), periodontitis group($0.7533{\pm}0.1185$) than in the normal group($l.1963{\pm}0.2044$)(P<0.05), but there was no statistical significance in the difference of GSH-PX activity in RBCs between the gingivitis group and periodontitis group(p>0.05). 2. Catalase activity in RBCs was siginficantly lower in the periodontitis group($117.34{\pm}35.01$) than in the normal group($l52.38{\pm}32.09$)(p<0.05). 3. GSH-PX activity in blood plasma was significantly increased in the posttreatment groupe $1.0376{\pm}0.2820$) compared to the pretreatment group(0.7608 0.1600) (p<0.05), and GSH-PX activity in RBC was significantly increased in the posttreatment group($1.0421{\pm}0.2330$) compared to the pretreatment group($0.7728{\pm}0.1210$)(p<0.05). 4. There was no statistical significance in the difference of catalase activity in RBCs between the pretreatment group($112.04{\pm}43.65$) and posttreatment group($l33.41{\pm}39.16$)(p>0.05).The results, within the limits of the present experiment, suggest that the lowered activity of GSH-PX and catalase in blood plasma and RBCs may be related with periodontopathogenesis.

• Journal of Food Hygiene and Safety
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• v.29 no.1
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• pp.16-20
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• 2014

The prevalence of Bacillus cereus was determined in salad and Kimbab obtained from commercial retailers. Among the 100 salad samples analyzed, 54 samples were negative for B. cereus, whereas the bacterial count was < 10 colony forming units (CFU)/g in 8 samples, < 100 CFU/g in 25 samples, < 1,000 CFU/g in 11 samples, and > 1,000 CFU/g in 2 samples. The mean (standard deviation) was 1.18 log CFU/g (${\pm}0.71$ log CFU/g). In Kimbab, B. cereus was isolated from 20 samples; the mean bacterial count was 1.01 log CFU/g (${\pm}0.71$ log CFU/g). On the basis of the monitoring data, a statistical sampling plan was determined with the NEW sampleplan program (ICMSF), which was used as an analytical tool. To identify the most suitable sampling plan, the microbial limits (m, M) and the maximum allowable number of sample units yielding unsatisfactory test results (c) were varied, but the number of samples units, n = 5, was fixed. Sampling plans showing an acceptable probability (Pa) over 0.95 were considered suitable. Two plans (A and B) were finally suggested. Parameters for plan A are n = 5, c = 0, m = 1,000, and M = 10,000 and for plan B are n = 5, c = 2, m = 100, and M = 1,000. Interestingly, the latter plan was identical to the microbial sampling plan used in New Zealand. Thus, it was concluded that the suggested plan can be used as a sampling plan that is in line with international standards.

• Journal of Soil and Groundwater Environment
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• v.13 no.6
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• pp.72-84
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• 2008

This study was carried out to provide proper management plans for small portable water supply system in the Nonsan area through water quality monitoring, hydrogeochemical investigation and multivariate statistical analyses. Nonsan area is a typical rural area heavily depending on small water supply system for portable usage. Geology of the area is composed of granite dominantly along with metasedimentary rocks, gneiss and volcanic rocks. The monitoring results of small portable water supply system showed that 13-21% of groundwaters have exceeded the groundwater standard for drinking water, which is 5 to 8 times higher than the results from the whole country survey (2.5% in average). The major components exceeding the standard limits are nitrate-nitrogen, turbidity, total coliform, bacteria, fluoride and arsenic. High nitrate contamination observed at southern and northern parts of the study area seems to be caused by cultivation practices such as greenhouses. Although Ca and $HCO_3$ are dominant species in groundwater, concentrations of Na, Cl and $NO_3$ have increased at the granitic area indicating anthropogenic contamination. The groundwaters are divided into 2 groups, granite and metasedimentary rock/gneiss areas, with the second principal component presenting anthropogenic pollution by cultivation and residence from the principal components analysis. The discriminant analysis, with an error of 5.56% between initial classification and prediction on geology, can explain more clearly the geochemical characteristics of groundwaters by geology than the principal components analysis. Based on the obtained results, it is considered that the multivariate statistical analysis can be used as an effective method to analyze the integrated hydrogeochemical characteristics and to clearly discriminate variations of the groundwater quality. The research results of small potable water supply system in the study area showed that the groundwater chemistry is determined by the mixed influence of land use, soil properties, and topography which are controlled by geology. To properly control and manage small water supply systems for central and local governments, it is recommended to construct a total database system for groundwater environment including geology, land use, and topography.

• Journal of Chest Surgery
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• v.42 no.1
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• pp.79-86
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• 2009

Background: Background: Computed tomography (CT) is the main tool for detecting abnormalities of the thoracic aorta, but conventional CT only shows the cross-sectional images. These CT images have some limitations fo accuratly measuring the thoracic aortic diameters at various levels. Multidetector computed tomography (MDCT) overcomes these limitations. We measured the thoracic aortic diameter perpendicular to the loop-shaped thoracic aortic course and this was studied in relation to age, gender, height, weight, the body surface area, the body mass index and the presence of hypertension. Material and Method: Thirty hundred thirty one patients (males: 141 patients and females: 190 patients) who had no abnormalities of the thoracic aorta were investigated using MDCT aortography. They were divided into three age categories: 20~39 years old, 40~59 years old and over age 60. The image was reformed with multiplanar reconstruction and the diameter of the aorta was measured perpendicular to the aortic course at 5 anatomic segments. Level A was the mid-ascending aorta, level B was the distal ascending aorta, level C was the aortic arch, level D was the aortic isthmus and level E was the mid-descending aorta. Result: The mean age was 49.5 years old for males and 54.9 years old for females (p<0.05). The mean diameter of the thoracic aorta at level A was 31.1 mm, that at level B was 30.2 mm, that at level C was 26.5 mm, that at level D was 24.0 mm and that at level E was 22.6 mm. The diameters at all the levels were gradually increased with age. Hypertensive patients had larger diameters than did the non-hypertensive population. There was a positive correlation between the ascending aortic diameter (levels A&B) and height and the body surface area, but there were no statistical differences at the aortic arch (level C) and the descending aorta (levels D&E). There were no statistical differences of the weight and body mass index at all levels. Conclusion: The diameters of the thoracic aortas were directly correlated with gender, age and hypertension. Height and the body surface area were only correlated with the ascending aorta. Weight and the body mass index have no statistical difference at all levels. We measured the age related thoracic aortic diameters and the upper normal limits and we provide this data as reference values for the thoracic aortic diameter in the Korean population.