• Journal of Environmental Science International
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• v.16 no.12
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• pp.1451-1462
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• 2007

Heavy metal concentrations in the soil were investigated for the abandoned Samkwang metal mine, Cheongyang-Gun, Chungnam Province, Korea. The concentrations of heavy metal(As, Cd, Cu, Ni, Pb, Zn) were determined in mine soils collected at the abandoned mine sites to obtain a general classification and specification of the pollution in this highly polluted region. The results estimated with the normal test and basis statistic on the central tendency and variation showed that the distribution of heavy metal concentration had significantly different at the range of all locations. The range of spatial distribution on the relationship of heavy metal concentration and pH was $4.8{\sim}8.8$ and heavy metal concentration on the type of land use was highest in forest land, and also Ni and Zn in farm and rice field showed the high concentration. The distribution of heavy metal concentration on the depth of a soil showed that the metal concentrations in subsoil were higher than of those in surface soil, while the concentration of Cu and Ni had no significant difference on the depth of soil. Results from the correlation analysis using the data except the extreme and unusual data revel that Zn-Cd(r=0.867), Zn-As(r=0.797), Zn-Pb(r=0.764), Cu-Cd(r=0.673), Cu-As(r=0.614) and Zn-Ni(r=0.605) were the most important parameters in assessing variations of heavy metal in soil. To discriminate pattern differences and similarities among samples, principal factor analysis(PFA) and cluster analysis(CF) were performed using a correlation matrix. This study suggests that PFA and CF techniques are useful tools for identification of important heavy metal and parameters. This study presents the necessity and usefulness of multivariate statistical assessment of complex databases in order to get better information about the quality of soil and gives the basis information to clean up the abandoned mine sites.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6081-6087
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• 2015

Purpose: This study aimed to investigate the incidence and mortality of breast cancer, and its relationship with human development index (HDI) and its components in Asia in 2012. Materials and Methods: This study was an ecologic study in Asia for assessment of the correlation between age-specific incidence rate (ASIR) and age-specific mortality rate (ASMR) with HDI and its details that include: life expectancy at birth, mean years of schooling and gross national income (GNI) per capita. Data about SIR and SMR for every Asian country for the year 2012 were obtained from the global cancer project. We used a bivariate method for assessment of the correlation between SIR and SMR and HDI and its individual components. Statistical significance was assumed if P<0.05. All reported P-values are two-sided. Statistical analyses were performed using SPSS (Version 15.0, SPSS Inc.). Results: In 2012, 639,824 cases of breast cancer were recorded in Asian countries. Countries with the highest standardized incidence rate (ASIR) (per 100,000) were Israel (80.5), Lebanon (78.7), Armenia (74.1) and the highest standard mortality rate (ASMR) was observed in Pakistan (25.2), Armenia (24.2), and Lebanon (24). There was a positive correlation between the ASIR of breast cancer and HDI (r = 0.556, p <0.001), whereas there was a negative correlation between the ASMR of breast cancer and HDI (r = -0.051). Conclusions: Breast cancer incidence in countries with higher development is greater, while mortality is greatest in countries with less development. There was a positive and significant relationship between the ASIR of breast cancer and HDI and its components. Also there was a negative but non significant relationship between the ASMR of breast cancer and HDI.

• Smart Structures and Systems
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• v.21 no.5
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• pp.591-600
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• 2018

The probabilistic characterization of wind field characteristics is a significant task for fatigue reliability assessment of long-span railway bridges in wind-prone regions. In consideration of the effect of wind direction, the stochastic properties of wind field should be represented by a bivariate statistical model of wind speed and direction. This paper presents the construction of the bivariate model of wind speed and direction at the site of a railway arch bridge by use of the long-term structural health monitoring (SHM) data. The wind characteristics are derived by analyzing the real-time wind monitoring data, such as the mean wind speed and direction, turbulence intensity, turbulence integral scale, and power spectral density. A sequential quadratic programming (SQP) algorithm-based finite mixture modeling method is proposed to formulate the joint distribution model of wind speed and direction. For the probability density function (PDF) of wind speed, a double-parameter Weibull distribution function is utilized, and a von Mises distribution function is applied to represent the PDF of wind direction. The SQP algorithm with multi-start points is used to estimate the parameters in the bivariate model, namely Weibull-von Mises mixture model. One-year wind monitoring data are selected to validate the effectiveness of the proposed modeling method. The optimal model is jointly evaluated by the Bayesian information criterion (BIC) and coefficient of determination, $R^2$. The obtained results indicate that the proposed SQP algorithm-based finite mixture modeling method can effectively establish the bivariate model of wind speed and direction. The established bivariate model of wind speed and direction will facilitate the wind-induced fatigue reliability assessment of long-span bridges.

• The Korea Journal of Herbology
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• v.30 no.3
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• pp.25-34
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• 2015

Objectives : This study was performed to investigate the efficacy and safety of the Mulberry Extract Complex in a placebo-controlled randomized clinical trial and animal study on degenerative arthritis. Methods : Animal study: Mulberry Extract Complex is composed of extracts of mulberry (Morus alba L.) fruit, mulberry leaves and black beans (Glycine max (L.) Merr.). To evaluate the serum level of interleukin-2, interferon-$\gamma$, and prostaglandin E2, an animal model of degenerative arthritis induced by monosodium iodoacetate was employed. Clinical study: The efficacy index (VAS, K-WOMAC) was compared among patients with symptoms of degenerative arthritis before and after Mulberry Extract Complex ingestion as well as the one in groups. Evaluations of the improvement by the subjects and by doctor assessment were also performed. Results : Animal study: Mulberry Extract Complex reduced the serum level of interferon-$\gamma$ and prostaglandin E2 in an animal model with degenerative arthritis. Clinical study: The VAS change showed statistical significance in the experimental groups after 4 weeks (PP set) and 8 weeks (ITT set) of ingestion. When the K-WOMAC was analyzed using a modified ITT set to determine the effectiveness, statistically significant results were obtained in the fields of pain & symptom within the Mulberry Extract Complex group as well as between the Mulberry Extract Complex and placebo groups after 8 weeks of ingestion. Results from the improvement evaluation by subjects and the assessment of improvement by doctors showed statistical significance in the experimental groups (PP set) after 8 weeks. Conclusions : Mulberry Extract Complex could be useful for the improvement of various symptoms of degenerative arthritis based on its anti-inflammatory activity and its reduction of VAS and K-WOMAC pain scores.

• Journal of Biosystems Engineering
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• v.42 no.1
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• pp.23-43
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• 2017

Purpose: As application-specific wireless sensor networks are gaining popularity, this paper discusses the development and field performance of the GHAN, a greenhouse area network system to monitor, control, and access greenhouse microenvironments. GHAN, which is an upgraded system, has many new functions. It is an intelligent wireless sensor and actuator network (WSAN) system for next-generation greenhouses, which enhances the state of the art of greenhouse automation systems and helps growers by providing them valuable information not available otherwise. Apart from providing online spatial and temporal monitoring of the greenhouse microclimate, GHAN has a modified vapor pressure deficit (VPD) fuzzy controller with an adaptive-selective mechanism that provides better control of the greenhouse crop VPD with energy optimization. Using the latest soil-matrix potential sensors, the GHAN system also ascertains when, where, and how much to irrigate and spatially manages the irrigation schedule within the greenhouse grids. Further, given the need to understand the microclimate control dynamics of a greenhouse during the crop season or a specific time, a statistical assessment tool to estimate the degree of optimality and spatial variability is proposed and implemented. Methods: Apart from the development work, the system was field-tested in a commercial greenhouse situated in the region of Punjab, India, under different outside weather conditions for a long period of time. Conclusions: Day results of the greenhouse microclimate control dynamics were recorded and analyzed, and they proved the successful operation of the system in keeping the greenhouse climate optimal and uniform most of the time, with high control performance.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.1 s.9
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• pp.71-80
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• 1997

This paper suggests a Map Accuracy Standards by analyzing U.S. National Map Accuracy Standards, by considering korean terrain feature and statistical error theory for paper and digital maps on the scale of 1:50,000. Map accuracy standards require horizontal accuracy to be reported as a circular error with 90% confidence level through Linear Error Probable(LEP) theory and Circular Error Probable(CEP) theory. In order to verify the proposed methodology for positioning accuracy testing, several kinds of test point were selected and tested. These test points were extracted at the centers of roads and bridges, the comers of the independent building, the edges of geographical botany, and the tops of mountains. The positioning accuracy assessment was peformed by comparing the positions of test points in digital maps generated three different sources with those acquired by high accurate GPS surveying. The digital maps were produced from aerial photographs and SPOT satellite image using analytical plotter and 1:50,000 paper map.

• Korean Journal of Community Nutrition
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• v.7 no.4
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• pp.548-558
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• 2002

The purpose of this study was to develop a computer software program for nutritional assessment using a Semi-Quantitative Food Frequency Questionnaire (SQFFQs) and the 24-hour Recall Method. The software for the SQFFQ was divided into input, output, and database. For dietary analyses, recipe and food databases were used. The recipe database included 25 items and the food database was divided into 18 food groups. The food database was composed of 19 general nutrient items, 33 fatty acids, and 18 amino acids. The software developed in this study can be summarized as follows: 1) input items related to the individual s ages information, lifestyle, biological values, and dietary habits; 2) individualized data in percent of the Korean RDA, the energy ratios of carbohydrates, proteins and fats, the ratio of animal to plant source intakes, and the distribution of food group intakes; 3) Statistical data on the individual's information, lifestyle, biological values, and dietary intakes including the frequency of intake of cooked foods, the amounts of food, and the number of food groups, and nutrients. In the 24-hour Recall Method, the input and output consisted of the individual s information and cooked dish intakes. The individual s report included the amounts of nutrient intake according to number of meal and days, in comparison to the Korean RDA, the energy ratio for carbohydrates, proteins and fats, the ratio of animal to plant source intakes, and the distribution of food group intakes. The statistical report presented the number of food groups and foods, and the nutrient intakes. To evaluate the validity of the SQFFQ, the Spearman Rank Order Correlation and kappa values were used. As a result, correlation coefficients comparing the 24-hour Recall Method appeared to be more than 0.5, except for vitamin $B_1, B_2$, niacin, and vitamin E. The kappa values for energy and carbohydrate intakes were both 0.7, and protein, fat, vitamin C, folate, Ca, and iron intakes ranged from 0.3 to 0.7.

• Journal of Korean society of Dental Hygiene
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• v.19 no.3
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• pp.437-448
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• 2019

Objectives: The purpose of this study was to suggest an effective instruction method for dental hygiene students by determining the degree of importance and satisfaction that they attach to the courses. Methods: Data obtained from a survey that was conducted on 654 dental hygiene students were analyzed. Statistical Package for the Social Sciences version 23.0 was used for the statistical analysis. A paired t-test was conducted to detect the differences between the degree of importance that the respondents attached to the courses and the degree of satisfaction they achieved. A comparative analysis of the two was performed using the IPA analysis. Results: Regarding the items, the respondents found the environment most important, followed by the content, method, perspective, and assessment. Regarding satisfaction, they were most satisfied with the environment, followed by the perspective, method, content, and assessment. Regarding the importance of ideal teaching, the respondents gave the highest priority to 'a class in which the core content is summarized, emphasized, and explained.' The satisfaction was the highest toward 'PowerPoint-based classes in which the core content is well-organized.' Based on the results of the IPA analysis, the respondents regarded 16 items as requiring maintenance and continuous efforts, 12 items as low priority, and 4 items as requiring excessive efforts and timely improvement. Conclusions: An ideal class requires the instructor to utilize various teaching methods that would enable the students to comprehend the detailed teaching content and elicit active interaction and feedback from the students through easy-to-understand lectures that are appropriate for students.

• Journal of Korean Society on Water Environment
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• v.37 no.6
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• pp.425-432
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• 2021

A tidal power plant (TPP) has been in operation since the end of 2011 to improve the water quality of Shihwa Coastal Reservoir (SCR). Tidal mixing rate increased 5.6 times after the TPP operation so that in this study, its effects on water quality was assessed through statistical analysis of long-term water quality monitoring data. It was found that the increased tidal mixing contributed to solving the hypoxia problem in the bottom water by preventing the summer stratification. The analysis also showed that the increased tidal mixing had different effects depending on the relative concentration difference for each water quality substances between the SCR and the outside of SCR. The average concentrations of some substances (chemical oxygen demand, total phosphorus, chlorophyll-a) with higher concentrations than the outside of SCR decreased due to the dilution effect, but the other substances (total nitrogen, dissolved inorganic nitrogen, dissolved inorganic phosphorus) with lower concentrations compared to the outside ones increased on the contrary. Factor analysis also showed a consistent result that the first factor accounting for the water quality was changed from the organic-related substances to the nutrient-related substances after the increased tidal mixing. These results imply that the focus of future water quality management needs shifting from the organic substances to the nutrients, particularly dissolved inorganic nutrients. Considering the effect of inflow seawater on the nutrients, the management area should be extended to cover not only SCR but also a certain area outside of SCR.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.343-350
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• 2024

Mobile electroencephalography (EEG) can continuously and objectively monitor construction workers' psychological stress, thereby contributing to enhanced safety and health. Traditional EEG-based stress assessment techniques utilize headset-type devices that cover the scalp, including the frontal area, which is the most relevant brain part to stress. Yet, the invasiveness of such devices may pose a potential barrier to their field application. In response, ear-EEG technology presents a less intrusive alternative for continuous monitoring, potentially overcoming the limitations of scalp-EEG. The temporal regions monitored by ear-EEG hold anatomical and functional significance in the brain's response to stress, suggesting that ear-EEG could effectively detect stress. Despite its advantage, the effectiveness of ear-EEG in stress detection remains underexplored, largely due to the existing literature's focus on frontal brain regions. To address this gap, the authors aim to evaluate ear-EEG's effectiveness in measuring stress and compare it to high-density scalp-EEG. EEG signals were collected with ear- and scalp-EEGs from 10 subjects in a controlled laboratory while they performed the mental arithmetic tasks under time pressure and socio-evaluative threats to induce stress at different levels (high vs. low). Subsequently, the authors performed t-tests and point-biserial analysis to analyze differences between high and low-stress conditions in the most reliable stress biomarkers in literature: high-beta power in temporal regions for ear-EEG, and alpha asymmetry in frontal regions for scalp-EEG. The results indicate that both EEG techniques could effectively differentiate between stress levels, with statistical significance (p <0.001 for both) and moderate effect size. Furthermore, the results demonstrate ear-EEG's comparable effectiveness to scalp-EEG in detecting stress-induced brain activity given the comparable statistical metrics, such as p-value and effect size. This study provides a groundwork for further explorations into leveraging ear-EEG as a practical tool for the early detection of stress, aiming to enhance stress management strategies within the construction industry.