• Journal of Preventive Medicine and Public Health
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• v.38 no.1
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• pp.45-52
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• 2005

Objectives : To investigate the fatigue subjective symptoms and VDT related risk factors in bank workers. Methods : A total of 2178 workers (62.8% male, 37.2% female) were surveyed with a self-administered and structured questionnaire consisting of 30 fatigue symptoms and other VDT related factors regarding work characteristics, work postures, work environments, personal medical histories, etc. Fatigue subjective symptoms were divided into 3 groups of 10 questions each: a dull, drowsy and exhausted feeling (Group I), a mental decline of working motivation (Group II), or a feeling of incongruity in the body and dysfunction of autonomic nervous system (Group III). Each question was weighted as 0 for 'none', 1 for 'sometimes', and 2 for 'always'. Results : Mean age was $35.8{\pm}7.2$ years ($38.9{\pm}6.0$ in males, $30.6{\pm}5.8$ in females), Mean work duration was $7.7{\pm}7.1$ years ($8.4{\pm}7.4$ in males, $6.5{\pm}6.4$ in females). Mean symptom score in males was $11.0{\pm}8.1$ ($4.9{\pm}3.1$ in Group I, $3.0{\pm}3.1$ in Group II, $3.1{\pm}2.8$ in Group III) and in females was $17.5{\pm}9.5$ ($7.0{\pm}3.8$ in Group I, $4.6{\pm}3.5$ in Group II, $5.9{\pm}3.4$ in Group III). Mean scores were higher in the order of Group I>III>II. Females had significantly higher scores than males in all three groups (p<0.001). Most common symptoms complained of as 'always' or 'sometimes' were feel strained in the eyes' (85.4%) among Group I, 'find difficulty in thinking'(54.2%) among Group II, and 'feel stiff in the shoulders (72.3%) among Group III. In multiple regression analysis, female, non-straight spine at workstation, more VDT work hours, history of physical therapy, glare of screen, overtime work, young age, and non-horizontal elbow position were significantly related with high score of symptoms. Conclusions : More supportive VDT work environment and education for correct work postures for VDT workers are recommended.

• Research in Plant Disease
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• v.22 no.3
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• pp.168-177
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• 2016

A forecast model for estimating the infection risk of bacterial canker caused by Pseudomonas syringae pv. actinidiae on kiwifruit leaves in Korea was developed using the generic infection model of Magarey et al. (2005). Two-way contingency table analysis was carried out to evaluate accuracy of forecast models including the model developed in this study for estimating the infection of bacterial canker on kiwifruit using the weather and disease data collected from three kiwifruit orchards at Seogwipo in 2015. All the tested models had more than 80% of probability of detection indicating that all the tested models could be effective to manage the disease. The model developed in this study showed the highest values in proportion of correct (51.1%), probability of detection (90.9%), and critical success index (47.6%). It indicated that the model developed in this study would be the best model for estimating the infection of bacterial wilt on kiwifruit leaves in Korea. The model developed in this study could be used for a part of decision support system for managing bacterial wilt on kiwifruit leaves and help growers to reduce the loss caused by the disease in Korea.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.909-918
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• 2009

As a part of dissolved organic matter, dissolved organic carbon (DOC) or biodegradable DOC (BDOC) fraction in particular is one of important issues in water treatment. Due to role as a nutrient source for bacteria, BDOC, therefore, may cause regrowth problems in water distribution system. The main objectives of this study were to investigate the possibility to minimize the concentration of BDOC in advance water treatment process. DOC in water is fractionized into four fractions such as AnBDOC (adsorbable and non-biodegradable DOC) which possesses adsorption properties but no biodegradation ability; nABDOC (biodegradable and non-adsorbable DOC) which has biodegradation properties but no adsorption ability; ABDOC (adsorbable and biodegradable DOC) which has adsorption properties and biodegradable characteristic; and non-removal DOC (nAnBDOC) which do not have either adsorbability or biodegradability. BAC process was effective for adsorbable DOC (AnBDOC+ABDOC) removal. However, in some cases, the removal ratio of adsorbable DOC was not sufficient. BDOC removal rate is very low or irremovable. Thus, for the control of residual DOC, it is necessary to change the operation condition by BAC process. From the analysis results of DOC fractions, water treatment processes appeared to be effective because it could grasp a remarkable amount of biodegradable, adsorbable and non-removal DOC. The concentration of AOX in non-prechlorination process was reduced from 7.1 ${\mu}g$/L to 0.51 ${\mu}g$/L in BAC process followed by ozonation.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.2
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• pp.7-12
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• 2012

Recently the medical field to efficiently process the vast amounts of information to decision trees, neural networks, Bayesian Networks, including the application method of various data mining techniques are investigated. In addition, the basic personal information or patient history, family history, in addition to information such as MRI, HRCT images and additional information to collect and leverage in the diagnosis of disease, improved diagnostic accuracy is to promote a common status. But in real world situations that affect the results much because of the variable exists for a particular data mining techniques to obtain information through the enemy can be seen fairly limited. Medical images were taken as well as a minor can not give a positive impact on the diagnosis, but the proportion increased subjective judgments by the automated system is to deal with difficult issues. As a result of a complex reality, the situation is more advantageous to deal with the relative probability of the multivariate model based on Bayesian network, or TAN in the K2 search algorithm improves due to expansion model has been proposed. At this point, depending on the type of search algorithm applied significantly influenced the performance characteristics of the extended Bayesian network, the performance and suitability of each technique for evaluation of the facts is required. In this paper, we extend the Bayesian network for diagnosis of diseases using the same data were carried out, K2, TAN and changes in search algorithms such as classification accuracy was measured. In the 10-fold cross-validation experiment was performed to compare the performance evaluation based on the analysis and the onset of high-risk classification for patients with HRCT images could be possible to identify high-risk data.

• The Korean Journal of Financial Management
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• v.22 no.1
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• pp.1-36
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• 2005

In this study, we analyzed determinant factors of leverage ratio and debt maturity for Korean firms in the simultaneous equation system using 2SLS (two stage least square) method under assumption that two variables are jointly determined in the capital structure decision. As a result of the analysis, we found that leverage ratio and debt maturity are positively related. Also, as for determinant factors of debt maturity, agency cost hypothesis, asset maturity matching hypothesis, signalling and liquidity risk hypothesis are all generally supported, and further leverage ratio are significantly positively related with firm size, but negatively related with default risk. However, when we divided samples into groups according to bank debt level and Chaebul affiliation, with contrast to existing study which worked on similar issues with OLS, we found no evidence supporting the argument that the information asymmetry problem is less severe in firms with more bank debt, whereas information asymmetry and financial constraint problems are more severe in non-Chaebul affiliated firms.

• Journal of Preventive Medicine and Public Health
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• v.37 no.3
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• pp.267-273
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• 2004

Objectives : This study was aimed at investigating the medical service utilization pattern of patients who use public medical aid compared to those who have health insurance. Methods : We selected every patient between the age of 18 and 69 who used public medical aid from January 1, 1999, to December 31, 2001, in Gwangju metropolitan city, South Korea. For comparison, a list of patients with health insurance was gathered for same period. Then the medical records of those who had been hospitalized for acute appendicitis were selected among both groups. Of those records, we compared the number of cases of ruptured appendicitis to cases of whole acute appendicitis in both groups. Regarding coding for ruptured appendicitis, International Classification of Diseases - 10 (ICD-10) was used. Multiple logistic regression was used as a statistical tool to determine the effectiveness of risk factors. Results : Even after adjusting for risk factors, such as age and sex, the proportion of perforation of acute appendicitis among public medical aid patients was found to be significantly higher than among insured patients. Conclusions : This comparative study on ruptured appendicitis among public medical aid patients and insured patients, indicates that the proportion of perforation of acute appendicitis could be an index showing that these types of patients utilize medical services differently than insured patients. We know that when abdominal pain is not properly treated at the outset, it easily develops into ruptured appendicitis complicated with peritonitis. Considering this data analysis, we guess the public medical aid system to have significant problem with medical accessibility. So additional and systematic research on the pattern of utilization of medical services of public medical aid patients is needed.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.1
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• pp.1-7
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• 2009

Most developed models are designed to determine pipe diameter, slope and overall layout in order to minimize the cost for the design rainfall for the optimal sewer layout. However, these models are not capable of considering the superposition effect of runoff hydrographs in the sewer pipes. The flow characteristics in the sewer pipes, such as the sewer layout, pipe diameter and slope, vary according to the design of the sewer system. In particular, when the sewer network is modified, the shapes of the runoff hydrographs in the sewer pipes also change because of the superposition effect. In this study, the sewer layout is designed to control and distribute the flows in the sewer pipes, while considering the runoff superposition effect, in order to reduce the inundation risk at each junction. This is accomplished by separating the inflows that enter into each junction by changing the way in which pipes are connected between junctions. And this model combines SWMM (Storm Water Management Model) to perform the hydraulic analysis for the flows in the sewer network. The current sewer layout was modified to minimize the peak outflow at outlet in Garak basin, Seoul, South Korea. As the results, the peak outflows at the outlet were decreased by approximately 20% for the design rainfall during 30 minutes and the total overflows were also decreased for the excessive rainfalls.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.609-619
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• 2017

A Manufacturing Readiness Assessment (MRA) was adapted to prevent the probable ascending expense, poor quality, and delay from the development to production phase and assess the level of manufacturing readiness in 2012. Consequently, there are positive effects on improving the quality to identify the manufacturing risks during the production of military supplies and manage the issues in advance. On the other hand, because the appraisee is becoming accustomed to preparing for MRA checklists tailoring, it was found to intensify the MRA points more than before, which damages the goal of the MRA. This paper proposes the quantitative MRA methodology using MWV (Manufacturing Readiness Level 8 Weighted Value) to define and measure the HOM8, DOM8, ICOM8, and M8RA to reflect the history of MRA, the difficulties of MRA checklists, the intrinsic cruciallity and risk assessment of program, which can overcome the problems mentioned before. This paper shows the MWV of four weapon system programs to be carried out and an analysis of the proposed MRL 8 methodology.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.3
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• pp.45-55
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• 2009

This study was intended to increase efficiency of traffic flow management on intersection. The result suggested to establish a left-turn at own risk lane to increase efficiency of traffic flow on intersection. The scope of the research was to investigate the geometric structure of a signal-controlled intersection, traffic volume(density) with respect to directions and traffic signal display, and to select a signalling intersection into which a car waiting for a traffic signal enters by adjusting the display sequence of traffic signal. The delay with respect to directions and for the whole intersection was compared for the current situation and an improvement plan. Using TSIS, a traffic analysis package, the traffic situation on an intersection was investigated. Based on the simulation result for Seok-Jeon intersection in Ma-San selected from the field investigation of intersections to which an improvement plans would be applicable, the waiting time in the direction without a entering traffic signal was decreased to be 78.6 seconds per car and that of the direction expecting the increase of waiting time was increased by 4 seconds per car only. It was confirmed that the waiting time for the whole intersection was improved.

• YAKHAK HOEJI
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• v.57 no.1
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• pp.8-17
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• 2013

The objective of this study is investigation of contamination levels and transfer rate of heavy metals and assessment of health risk effects in animal medicines. A total of sixteen items with 148 samples were obtained for this investigation from major herbal medicine producing areas and herbal markets from 2011 to 2012. Inductively coupled plasma mass spectrometer method was conducted for the quantitative analysis of Pb, Cd and As. In addition, the mercury analyzer system was conducted for that of Hg without sample digestion. The average contents of heavy metals in animal medicines were as follows : 1.55 mg/kg for Pb, 0.28 mg/kg for Cd, 0.70 mg/kg for As and 0.047 mg/kg for Hg respectively. The average contents of heavy metals in decoctions were as follows : 0.03 mg/kg for Pb, 0.01 mg/kg for Cd, 0.17 mg/kg for As and 0.003 mg/kg for Hg respectively. The average transfer rates of heavy metals from animal medicines to decoctions were 1.9% for Pb, 3.6% for Cd, 24.2% for As and 6.0% for Hg respectively. Cancer risks of animal medicines and decoctions through slope factor by ministry of environment republic korea and environmental protection agency was $1.36{\times}10^{-6}$ and $2.50{\times}10^{-8}$ for Pb and $7.46{\times}10^{-5}$ and $1.98{\times}10^{-5}$ for As (assuming that the total arsenic content was equal to the inorganic arsenic) respectively. The hazard index of heavy metals in animal medicines and decoctions was below recommended hazard index as 0.52 and 0.05 respectively. Taken together, cancer risks about Pb and hazard indexes of animal medicines and decoctions indicate that the majority of samples except for some samples with relative high contents of heavy metals were safe. But cancer risks about As of animal medicines indicate that the majority of samples were not relatively safe.