• Journal of agricultural medicine and community health
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• v.37 no.4
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• pp.223-232
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• 2012

Objectives: The objective of this study was to identify the relationship between fish consumption and blood mercury levels in a sample of adult Koreans. Methods: The study subjects were 299 residents of Busan (male: 65, female: 234) and 185 residents of Namhae (male: 69, female: 116), South Korea. Demographic characteristics, current smoking, current drinking, fish consumption per week, past history of amalgam treatment, and residential district were recorded by trained interviewers in June and July, 2009. We considered a portion of fish to be equivalent to 70 gm weight, and calculated amounts of fish consumed per week. Using chi-square tests, t-tests, ANOVA, and multiple linear regression analysis, we estimated the relationships between blood mercury levels and amount of fish consumed per week and other factors. Results: The mean blood mercury level of our subjects was 6.61 ${\mu}g/L$, higher than the criterion defined by the United States Environmental Protection Agency (EPA) (5.8 ${\mu}g/L$). In multiple linear regression analysis, residential district and amount of fish consumed per week were associated with blood mercury levels. However, marital status, current drinking, and gender, and age were not associated with blood mercury levels. Conclusions: In conclusion, we suggest the implementation of systematic and periodic population-based studies to decrease the risks of mercury poisoning among South Koreans who consume fish as a regular part of the diet.

• Journal of agricultural medicine and community health
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• v.38 no.2
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• pp.116-129
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• 2013

Objectives: This study was performed to identify the associations of social capital with suicidal thoughts and attempts in Korean communities with poor health. Methods: We used the data from community health interviews conducted at 40 administrative sections (dong, eup, or myeon) with high mortality from August to October in 2010, 2011, and 2012 as part of the Health Plus Happiness Plus Projects in Gyeongsangnam-do Province. The 8,800 study subjects composed of 220 adults systematically sampled from each administrative section were asked if they had thought about suicide or had attempted suicide within 1 year. The social participation was measured with 'participation in formal and/or informal group' and trust using responses to three questions about trust of others. Results: The prevalence of suicidal ideation and attempt within 1 year were 10.4% and 0.8%, respectively. The logistic regression analysis revealed that those who participated in only informal groups, or had highest trust level reported less suicidal ideation, or attempt after adjusting for socio-demographic factors (sex, age, marital status, occupation, and food affordability), self-rated health, and health behaviors (smoking, alcohol drinking, and exercise). Conclusions: This study suggested social capital such as social participation and trust was associated with less suicide ideation and attempt. More studies are warranted for the association of social capital with suicidal behavior.

• Journal of Intelligence and Information Systems
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• v.19 no.2
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• pp.39-54
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• 2013

Recent explosive increase of electronic commerce provides many advantageous purchase opportunities to customers. In this situation, customers who do not have enough knowledge about their purchases, may accept product recommendations. Product recommender systems automatically reflect user's preference and provide recommendation list to the users. Thus, product recommender system in online shopping store has been known as one of the most popular tools for one-to-one marketing. However, recommender systems which do not properly reflect user's preference cause user's disappointment and waste of time. In this study, we propose a novel recommender system which uses data mining and multi-model ensemble techniques to enhance the recommendation performance through reflecting the precise user's preference. The research data is collected from the real-world online shopping store, which deals products from famous art galleries and museums in Korea. The data initially contain 5759 transaction data, but finally remain 3167 transaction data after deletion of null data. In this study, we transform the categorical variables into dummy variables and exclude outlier data. The proposed model consists of two steps. The first step predicts customers who have high likelihood to purchase products in the online shopping store. In this step, we first use logistic regression, decision trees, and artificial neural networks to predict customers who have high likelihood to purchase products in each product group. We perform above data mining techniques using SAS E-Miner software. In this study, we partition datasets into two sets as modeling and validation sets for the logistic regression and decision trees. We also partition datasets into three sets as training, test, and validation sets for the artificial neural network model. The validation dataset is equal for the all experiments. Then we composite the results of each predictor using the multi-model ensemble techniques such as bagging and bumping. Bagging is the abbreviation of "Bootstrap Aggregation" and it composite outputs from several machine learning techniques for raising the performance and stability of prediction or classification. This technique is special form of the averaging method. Bumping is the abbreviation of "Bootstrap Umbrella of Model Parameter," and it only considers the model which has the lowest error value. The results show that bumping outperforms bagging and the other predictors except for "Poster" product group. For the "Poster" product group, artificial neural network model performs better than the other models. In the second step, we use the market basket analysis to extract association rules for co-purchased products. We can extract thirty one association rules according to values of Lift, Support, and Confidence measure. We set the minimum transaction frequency to support associations as 5%, maximum number of items in an association as 4, and minimum confidence for rule generation as 10%. This study also excludes the extracted association rules below 1 of lift value. We finally get fifteen association rules by excluding duplicate rules. Among the fifteen association rules, eleven rules contain association between products in "Office Supplies" product group, one rules include the association between "Office Supplies" and "Fashion" product groups, and other three rules contain association between "Office Supplies" and "Home Decoration" product groups. Finally, the proposed product recommender systems provides list of recommendations to the proper customers. We test the usability of the proposed system by using prototype and real-world transaction and profile data. For this end, we construct the prototype system by using the ASP, Java Script and Microsoft Access. In addition, we survey about user satisfaction for the recommended product list from the proposed system and the randomly selected product lists. The participants for the survey are 173 persons who use MSN Messenger, Daum Caf$\acute{e}$, and P2P services. We evaluate the user satisfaction using five-scale Likert measure. This study also performs "Paired Sample T-test" for the results of the survey. The results show that the proposed model outperforms the random selection model with 1% statistical significance level. It means that the users satisfied the recommended product list significantly. The results also show that the proposed system may be useful in real-world online shopping store.

• Journal of Preventive Medicine and Public Health
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• v.28 no.4 s.51
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• pp.795-807
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• 1995

This study was carried out from 1993 to 1994 in the small industries in Incheon. The objectives of this study was in order to estimate the quitting rate, to identify its relating factors and to propose effective quitting management policy in the small industries. The results were as follows ; 1. The quitting rate of 266 study workers was 42.1%(112 workers). 2. Age, working duration, position, marrital status were significant difference between the quitting group and the non - quitting group. In the quitting group, mean age was young, working duration was short, general employees and unmarried workers were many compared with the non - quitting group. 3. In the industry characteristics, total assets, total assets, sales per person, establishment duration and occupational health and safely status were significant difference between the quitting group and the non - quitting group. In the quitting group, total assets, total sales and sales per person were little, establishment duration of company was short and occupational health and safety status were poor compared with the non - quitting group. 4. In the quitting group, worker's response to employer's disposal about health and safety was more passive and the relation to employer with employee was significantly poor compared with the non - quitting group. 5. Multiple logistic regression analysis of quitting against family income per person, working duration, relation to employer with employee, occupational health and safety status in industry, worker's response to employer's disposal about health and safety and sales per person was done. Working duration, occupational health and safety status, worker's response to employer'1 disposal about health and safety were significant explainatory variables for quitting. Above results showed that the quitting rate was high and it was significant difference between the quitting group and non : quitting group according to characteristics of workers and of industries. Especially, it suggested that working duration, occupational health and safety status and worker's response to employer's disposal about health and safety were significant quitting factor. Therefore, it should be reflected in the quitting management and the policy of steady employment.

• Current Research on Agriculture and Life Sciences
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• v.14
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• pp.49-60
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• 1996

In order to evaluate soil factors affecting the growth of Italian poplar, 23 areas planted with Italian poplar were surveyed. These 23 areas were classified into 3 categories, river-side, fallow-land and hill-side. The growth performance and soil factors for each area were investigated. The growth of Italian poplar at river-side was shown to be superior to that of fallow-land and fill-side. The rates of growth for fallow-land and hill-side are decreased by 8% and 21% compared to those of river-side, respectively. This suggests that plantation of Italian poplar at hill-side would not be profitable. Soil conditions of high productive area appeared liquid phase 20%, porosity 45%, water holding capacity 35 - 40%, soil hardness $1kg/cm^3$. pH 6 and rich in organic matter and total nitrogen. The results of factor analysis for soil factors affecting to Italian poplar growth that showed eigenvalue over 1 and communality value over 70% explained factor 1 : liquid phase, porosity and water holding capacity, factor 2 : pH and calcium, and factor 3 : soil hardness. This suggests that physical characteristics of soil is more important than chemical characteristics for Italian poplar growth. Multiregerssion analysis was conducted between diameter growth and soil hardness, liquid phase and calcium. The t-values for each independent variables showed significance at 1 - 10% level, but water holding capacity and pH are not significant. It is supposed that sites suitable to Italian poplar were alluvial plain of sandy loam or part of banking soil, well-ventilating soil, lower soil hardness, apposite soil moisture absorbing with about 100cm of ground water level, plentiful organic matters and total nitrogen and little acidity soil.

• Journal of Nutrition and Health
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• v.47 no.2
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• pp.124-133
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• 2014

Purpose: The current study was designed for development of a simplified malnutrition screening tool (SMST) for hospitalized patients using readily available laboratory and patient information and for evaluation of its reliability compared to well-established tools, such as PGSGA and NRS-2002. Methods: Anthropometric and biochemical measurements, as well as a few subjective assessments, of 903 patients who were preclassified by their nutritional status according to PGSGA were analyzed. Among them, a combination of factors, including age, BMI, albumin, cholesterol, total protein, hematocrit, and changes in body weight and food intake, were statistically selected as variables for SMST. Results: According to SMST, 620 patients (68.7%) were classified as the normal group and 283 patients (31.3%) were classified as the malnutrition group. Significant differences in age, albumin, TLC, BMI, hemoglobin, hematocrit, total protein, cholesterol, and length of stay were observed between the two groups. For inter-methods reliability, the screening results by SMST were compared with those by PGSGA and NRS-2002. The comparison with PGSGA and NRS-2002 showed 'Substantial agreement' (sensitivity 94.4%, specificity 88.4%, ${\kappa}$ = 0.747) and 'Moderate agreement' (sensitivity 96.1%, specificity 79.5%, ${\kappa}$ = 0.505), respectively, indicating that SMST held high inter-methods reliability. Conclusion: In conclusion, SMST, based on readily available laboratory and patient information and simple subjective assessments on changes in food intake and body weight, may be a useful alternative tool with a simple but reliable risk index, especially in resource-limited domestic hospitals.

• Korean Journal of Remote Sensing
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• v.25 no.1
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• pp.31-44
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• 2009

The objective of this study was to measure backscattering coefficients of paddy rice using a L-, C-, and X-band scatterometer system with full polarization and various angles during the rice growth period and to relate backscattering coefficients to rice growth parameters. Radar backscattering measurements of paddy rice field using multifrequency (L, C, and X) and full polarization were conducted at an experimental field located in National Academy of Agricultural Science (NAAS), Suwon, Korea. The scatterometer system consists of dual-polarimetric square horn antennas, HP8720D vector network analyzer ($20\;MHz{\sim}20\;GHz$), RF cables, and a personal computer that controls frequency, polarization and data storage. The backscattering coefficients were calculated by applying radar equation for the measured at incidence angles between $20^{\circ}$ and $60^{\circ}$ with $5^{\circ}$ interval for four polarization (HH, VV, HV, VH), respectively. We measured the temporal variations of backscattering coefficients of the rice crop at L-, C-, X-band during a rice growth period. In three bands, VV-polarized backscattering coefficients were higher than hh-polarized backscattering coefficients during rooting stage (mid-June) and HH-polarized backscattering coefficients were higher than VV-, HV/VH-polarized backscattering coefficients after panicle initiation stage (mid-July). Cross polarized backscattering coefficients in X-band increased towards the heading stage (mid-Aug) and thereafter saturated, again increased near the harvesting season. Backscattering coefficients of range at X-band were lower than that of L-, C-band. HH-, VV-polarized ${\sigma}^{\circ}$ steadily increased toward panicle initiation stage and thereafter decreased, and again increased near the harvesting season. We plotted the relationship between backscattering coefficients with L-, C-, X-band and rice growth parameters. Biomass was correlated with L-band hh-polarization at a large incident angle. LAI (Leaf Area Index) was highly correlated with C-band HH- and cross-polarizations. Grain weight was correlated with backscattering coefficients of X-band VV-polarization at a large incidence angle. X-band was sensitive to grain maturity during the post heading stage.

• Journal of Society of Occupational Therapy for the Aged and Dementia
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• v.12 no.2
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• pp.87-95
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• 2018

Objective : Vibration stimulators are easier to obtain in clinical settings than other treatment tools, and it is advantageous that the arm activation training can be performed passively. Despite the following advantages, recent studies on vibration sense have not been activated yet. The purpose of this study was to investigate the effect of vibration sensation on the hands of the affected upper limb on unilateral reduction of stroke patients. Method : Patients with unilateral neglect due to stroke were enrolled in this study for about 3 weeks from October 19, 2018 to November 7, The research design used ABA design among the single-subject experimental research design, and a total of 18 circuits (4 baseline, 6 intervention, 3 baseline regression) were performed once a day on weekdays Respectively. MMES-K was used to select the subjects. Line bisection test (LBT), Albert's test and Star Cancellation Test (SCT) were used as unilateral neglect test. For the analysis, the baseline and intervention period measurements were visually analyzed using graphs and mean values were used. Result : All three evaluations showed that the number of errors missed during the training period was lower than the baseline period, and this decrease remained after training. The error was reduced by an average of $2{\pm}1.2$ omissions and an average omissions of $0.6{\pm}0.5$ omitting an average of $4.5{\pm}1$ omissions in the line break test. As a result of the Albert test, the average error decreased by $22.5{\pm}1.9$ omissions and $8{\pm}7.3$ omissions and $0.3{\pm}0.5$ omissions, respectively. In the star clearance test, the average error decreased from $26{\pm}4.6$ to $21.8{\pm}1.7$ and $20{\pm}0$, respectively. Conclusion : In this study, vibrotactile stimulation therapy showed a continuous effect on improving unilateral neglect. Based on these findings, further research should be conducted in order to improve objectivity in future studies. Further research on various arbitration methods that maximize the effect of intervention will be needed.

• Journal of Korea Port Economic Association
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• v.38 no.3
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• pp.133-149
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• 2022

The Port logistics is a pivotal industry in strengthening competitiveness for countries and companies and plays an important role in accounting for the majority of Korea's import and export volume, so its importance among Korea's industries is truly enormous. The port, which plays such an important role, is simultaneously unloaded, transferred into the dock, and stored, and it can be said that it is composed of a very complex flow. In particular, port unloading is an environment in which port unloading workers cannot escape the risk of disasters as large cargoes and cranes for container transport move, and numerous disasters are hidden and lead to serious disasters. Through literature studies on the Serious Accident Penalty Act, this study investigated how the Serious Accident Penalty Act affected port unloading workers and whether there was a change in satisfaction with safety education according to the enforcement of the Serious Accident Penalty Act. Through this study, it was found that port unloading workers were more aware of safety than managers in cognitive, attitude, and experience factors. Since the port unloading manager is not put into the unloading work, the perception of safety was analyzed to be lower than that of workers. Since managers should educate workers on safe work and be alert to safety, it seems that port unloading managers will also need to change their perception of safety. The Act on the Punishment of Severe Disasters took effect on January 27, 22, and in the early stages of the enforcement of the law, many confusing and ambiguous parts are found for those in charge of performing practical tasks on the front line until the law is settled. It seems necessary to revise the Act on the Punishment of Severe Disasters for the purpose of clear standards for the law and no safety accidents in the field to prevent confusion in work. In addition, in order to derive more meaningful research results in the future, it is expected that research on the perception of disasters by workers and managers will be continuously needed by deepening literature research to find various factors and using investigation methods such as interviews.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4B
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• pp.337-346
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• 2010

Climate change has a huge impact on various parts of the world. This study quantified and analyzed the effects on hydrological behavior caused by climate, vegetation canopy and land use change of Soyanggang dam watershed (2,694.4 $km^2$) using the semi-distributed model SWAT (Soil Water Assessment Tool). For the 1997-2006 daily dam inflow data, the model was calibrated with the Nash-Sutcliffe model efficiencies between the range of 0.45 and 0.91. For the future climate change projection, three GCMs of MIROC3.2hires, ECHAM5-OM, and HadCM3 were used. The A2, A1B and B1 emission scenarios of IPCC (Intergovernmental Panel on Climate Change) were adopted. The data was corrected for each bias and downscaled by Change Factor (CF) method using 30 years (1977-2006, baseline period) weather data and 20C3M (20th Century Climate Coupled Model). Three periods of data; 2010-2039 (2020s), 2040-2069 (2050s), 2070-2099 (2080s) were prepared for future evaluation. The future annual temperature and precipitation were predicted to change from +2.0 to $+6.3^{\circ}C$ and from -20.4 to 32.3% respectively. Seasonal temperature change increased in all scenarios except for winter period of HadCM3. The precipitation of winter and spring increased while it decreased for summer and fall for all GCMs. Future land use and vegetation canopy condition were predicted by CA-Markov technique and MODIS LAI versus temperature regression respectively. The future hydrological evaluation showed that the annual evapotranspiration increases up to 30.1%, and the groundwater recharge and soil moisture decreases up to 55.4% and 32.4% respectively compared to 2000 condition. Dam inflow was predicted to change from -38.6 to 29.5%. For all scenarios, the fall dam inflow, soil moisture and groundwater recharge were predicted to decrease. The seasonal vapotranspiration was predicted to increase up to 64.2% for all seasons except for HadCM3 winter.