• Journal of Preventive Medicine and Public Health
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• v.39 no.1
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• pp.39-45
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• 2006

Objectives: This study estimated the burden of disease especially caused by psychiatric disorders in Korea by using DALY, a composite indicator that was recently developed by the Global Burden of Disease study group. Methods: First, 11 of the major psychiatric disorders in Korea were selected based on the ICD-10. Second, the burden of disease due to premature death was estimated by using YLLs (years of life lost due to premature death). Third, for the calculation of the YLD (years lived with disability), the following parameters were estimated in the formula: the incidence rate, the prevalence rate and the disability weight of each psychiatric disorder. Last, we estimated the DALY of the psychiatric disorders by adding the YLLs and YLDs. Results: The burden of psychiatric disorder per 100,000 people was attributed mainly to unipolar major depression (1,278 person-years), schizophrenia (638 person-years) and alcohol use disorder (287 person-years). For males, schizophrenia (596 person-years) and alcohol use disorder (491 person-years) caused the highest burden. For females, unipolar major depression (1,749 person-years) and schizophrenia (680 person-years) cause the highest burden. As analyzed by gender and age group, alcohol use disorder causes a higher burden than schizophrenia in men aged 40 years and older. For females, unipolar major depression causes the highest burden in all age groups. Conclusions: We found that each of the psychiatric disorders that cause the highest burden is different according to gender and age group. This study's results can provide a rational basis to plan a national health policy regarding the burden of disease caused by psychiatric disorders.

• Journal of the Korea Society of Computer and Information
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• v.28 no.10
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• pp.27-35
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• 2023

In this paper, we propose a process of increasing productivity by applying a deep learning-based defect detection and classification system to the prepreg fiber manufacturing process, which is in high demand in the field of producing composite materials. In order to apply it to toe prepreg manufacturing equipment that requires a solution due to the occurrence of a large amount of defects in various conditions, the optimal environment was first established by selecting cameras and lights necessary for defect detection and classification model production. In addition, data necessary for the production of multiple classification models were collected and labeled according to normal and defective conditions. The multi-classification model is made based on CNN and applies pre-learning models such as VGGNet, MobileNet, ResNet, etc. to compare performance and identify improvement directions with accuracy and loss graphs. Data augmentation and dropout techniques were applied to identify and improve overfitting problems as major problems. In order to evaluate the performance of the model, a performance evaluation was conducted using the confusion matrix as a performance indicator, and the performance of more than 99% was confirmed. In addition, it checks the classification results for images acquired in real time by applying them to the actual process to check whether the discrimination values are accurately derived.

• Journal of the Mineralogical Society of Korea
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• v.22 no.2
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• pp.139-151
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• 2009

Mineralogical characteristics of secondary precipitate formed at some mineral water springs in Gyeongbuk Province, Korea were studied in relation to water chemistry. The chemical water types of mineral water springs are mostly classified as $Ca-HCO_3$ type, but $Na(Ca)-HCO_3$ and $Ca-SO_4$ types are also recognized. Ca, Fe, and $HCO_3\;^-$ are the most abundant components in the water. The pH values of most springs lie in 5.76${\sim}$6.81, except Hwangsu spring having pH 2.8. Saturation indices show that all springs are supersaturated with respect to iron minerals and oxyhydroxides such as hematite and goethite. The result of particle size analysis shows that the precipitate is composed of the composite with various sizes, indicating the presence of iron minerals susceptible to a phase transition at varying water chemistry or the mixtures consisting of various mineral species. The particle size of the reddish precipitate is larger than that of the yellow brown precipitate. Based on XRD and SEM analyses, the precipitate is mostly composed of ferrihydrite (two-line type), goethite, schwertmannite, and calcite, with lesser silicates and manganese minerals. The most abundant mineral fanned at springs is ferrihydrite whose crystals are $0.1{\sim}2\;{\mu}m$ with an average of $0.5\;{\mu}m$ in size, characterized by a spherical form. It should be interestingly noted that schwertmannite forms at Hwangsu spring whose pH is very low. At Shinchon spring, Gallionella ferruginea, one of the iron bacteria, is commonly found as an indicator of the important microbial activity ascribed to the formation of iron minerals because very fine iron oxides with a spherical form are closely distributed on surfaces of the bacteria. A genetic relationship between the water chemistry and the formation of the secondary precipitate from mineral water springs was discussed.

• Asia pacific journal of information systems
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• v.24 no.4
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• pp.559-575
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• 2014

Individual investors are increasingly flocking to message boards to seek, clarify, and exchange information. Businesses like Seekingalpha.com and business magazines like Fortune are evaluating, synthesizing, and reporting the comments made on message boards or blogs. In March of 2012, Yahoo! Finance Message Boards recorded 45 million unique visitors per month followed by AOL Money and Finance (19.8 million), and Google Finance (1.6 million) [McIntyre, 2012]. Previous studies in the finance literature suggest that online communities often provide more accurate information than analyst forecasts [Bagnoli et al., 1999; Clarkson et al., 2006]. Some studies empirically show that the volume of posts in online communities have a positive relationship with market activities (e.g., trading volumes) [Antweiler and Frank, 2004; Bagnoli et al., 1999; Das and Chen, 2007; Tumarkin and Whitelaw, 2001]. The findings indicate that information in online communities does impact investors' investment decisions and trading behaviors. However, research explicating the correlation between information on online communities and stock market activities (e.g., trading volume) is still evolving. Thus, it is important to ask whether a volume of posts on online communities influences trading volumes and whether trading volumes also influence these communities. Online stock message boards offer two different types of information, which can be explained using an economic and a psychological perspective. From a purely economic perspective, one would expect that stock message boards would have a beneficial effect, since they provide timely information at a much lower cost [Bagnoli et al., 1999; Clarkson et al., 2006; Birchler and Butler, 2007]. This indicates that information in stock message boards may provide valuable information investors can use to predict stock market activities and thus may use to make better investment decisions. On the other hand, psychological studies have shown that stock message boards may not necessarily make investors more informed. The related literature argues that confirmation bias causes investors to seek other investors with the same opinions on these stock message boards [Chen and Gu, 2009; Park et al., 2013]. For example, investors may want to share their painful investment experiences with others on stock message boards and are relieved to find they are not alone. In this case, the information on these stock message boards mainly reflects past experience or past information and not valuable and predictable information for market activities. This study thus investigates the two roles of stock message boards-providing valuable information to make future investment decisions or sharing past experiences that reflect mainly investors' painful or boastful stories. If stock message boards do provide valuable information for stock investment decisions, then investors will use this information and thereby influence stock market activities (e.g., trading volume). On the contrary, if investors made investment decisions and visit stock message boards later, they will mainly share their past experiences with others. In this case, past activities in the stock market will influence the stock message boards. These arguments indicate that there is a correlation between information posted on stock message boards and stock market activities. The previous literature has examined the impact of stock sentiments or the number of posts on stock market activities (e.g., trading volume, volatility, stock prices). However, the studies related to stock sentiments found it difficult to obtain significant results. It is not easy to identify useful information among the millions of posts, many of which can be just noise. As a result, the overall sentiments of stock message boards often carry little information for future stock movements [Das and Chen, 2001; Antweiler and Frank, 2004]. This study notes that as a dependent variable, trading volume is more reliable for capturing the effect of stock message board activities. The finance literature argues that trading volume is an indicator of stock price movements [Das et al., 2005; Das and Chen, 2007]. In this regard, this study investigates the correlation between a number of posts (information on stock message boards) and trading volume (stock market activity). We collected about 100,000 messages of 40 companies at KOSPI (Korea Composite Stock Price Index) from Paxnet, the most popular Korean online stock message board. The messages we collected were divided into in-trading and after-trading hours to examine the correlation between the numbers of posts and trading volumes in detail. Also we collected the volume of the stock of the 40 companies. The vector regression analysis and the granger causality test, 3SLS analysis were performed on our panel data sets. We found that the number of posts on online stock message boards is positively related to prior stock trade volume. Also, we found that the impact of the number of posts on stock trading volumes is not statistically significant. Also, we empirically showed the correlation between stock trading volumes and the number of posts on stock message boards. The results of this study contribute to the IS and finance literature in that we identified online stock message board's two roles. Also, this study suggests that stock trading managers should carefully monitor information on stock message boards to understand stock market activities in advance.

• Journal of Food Hygiene and Safety
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• v.30 no.3
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• pp.227-235
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• 2015

Food-Health indicators have been developed and utilized internationally in the 'Food' domain of environment and health indicators. In Korea, however, Food Safety Health Indicators which are in the introductory stage had been developed separately from Environmental Health Indicators. The aim of the current study is to suggest feasible applications of the domestic Food Safety Health Indicators as a case study. We introduced 3 possible applications which are as follows: 1) production of two types of Integrated Food Safety Health Index; 2) conduction of correlation analysis between the Integrated Food Safety Health Index and Food Safety Health Indicators; 3) conduction of regression analysis to evaluate the relationship between the Integrated Food Safety Health Index and socioeconomic status. As a result, we provided the calculated Integrated Food Safety Health Index I and Integrated Food Safety Health Index II, which represents the regional food safety level in relative and absolute terms, respectively. Integrated Food Safety Health Index I was significantly correlated with the outbreaks of food-borne diseases (caused by Campylobacter jejuni, Bacillus cereus, Salmonella spp. and unknown cause) and incidence of E.coli infections. Integrated Food Safety Health Index II significantly decreased as the proportion of foreigners and women increased, and increased as the population density increased. Utilization of such Integrated Food Safety Health Indicators may be helpful in understanding the overall domestic food safety level and identifying the indicators which must be considered with priorities to enhance the food safety levels regionally and domestically. Furthermore, analyzing the association between Integrated Food Safety Health Index and factors other than food safety could be useful in conducting risk management and identifying susceptible populations. Food Safety Health Indicators can be useful in other applications, and may serve as a supporting material in establishing or modifying policy plans to enhance food safety. Therefore, keen interests by researchers accompanied by further studies on food safety health indicators are needed.