• Journal of the Korea Society for Simulation
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• v.24 no.3
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• pp.97-105
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• 2015

This paper is to analyze the efficiency of power consumption in logistic systems that are based on self-driving roller conveyors by the simulation technology. The improvement of the efficiency brings advantages for reducing greenhouse gas emission and logistics costs. A self-driving roller conveyor is operated only when products are loaded on itself. Thus, the self-driving roller conveyor systems consume less electric power than continuous-driving roller conveyor systems. In this paper, we design a DEVS (Discrete-Event based System) based simulation model and construct self-driving roller and continuous-driving roller conveyor models. For the verification and validation of the designed simulation system and conveyor models, we model a corresponding logistic model for the experimental environment and compare between the model and a real system. The main objective of this paper is to describe the power consumption advantage of self-driving roller conveyor based logistic systems using a simulation method.

• Journal of Preventive Medicine and Public Health
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• v.37 no.1
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• pp.37-43
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• 2004

Objectives : This study was carried out to understand the prevalence and risk factors of green tobacco sickness (GTS) among Korean tobacco harvesters. Methods : The authors conducted a questionnaire among the tobacco harvesters (1,064 persons from 555 out of 723 tobacco harvesting households) in Cheongsong-gun for 4 days from May 7 to 10, 2002. Results : The study subjects were 550 males and 514 females. The recognition and experience of GTS up until 2001 were 96.4% and 61.9%, respectively. The prevalence of GTS in 2001 was 42.5%, and was significantly higher in females than in males (59.0% vs. 26.6%, p<0.01). The incidence density of GTS according to the number of workdays in 2001 was 12.3 spells/100 person..days. The GTS symptoms reported by the tobacco harvesters in 2001 were dizziness in 441 cases (97.6%), nausea in 414 (91.6%), headache in 349 (77.2%) and vomiting in 343 (75.9%). The use of gloves, hat and wristlets, sweating at work and the number of working hours significantly increased the prevalence of GTS (p<0.05). Multiple logistic re- gression analysis was used to determine the factors significantly associated with GTS. Odds ratios for smoking, working over 10 hours and sweating at work were 0.26 (95% CI:0.19-0.35), 1.64 (95% CI:1.26-2.14) and 1.60 (95% CI:1.14-2.25), respectively. Of those who reported GTS in 2001, 311 cases (68.8%) underwent treatment from their local medical facilities. Conclusions : In Korea, there are many tobacco-harvesting households, and most may be stricken with GTS. More extensive epidemiological studies, including the incidence and associated risk factors, are expected and a surveillance system including measurements of cotinine in urine should be conducted.

• Journal of the Korean Society for Railway
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• v.15 no.5
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• pp.517-523
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• 2012

Double Stack Train(DST) is being used variously around USA and Canada. The greatest advantage of the DST is mass transportation without extending the length of freight train and number of cars. So the DST system can be a kind of innovative train to increase the competitiveness of rail logistic business. As the domestic rail logistic increase, for enhancement of environment friendly green transportation amount, the DST needs more for efficiency. In this study, as the alternative way to introduce the DST to the Kyungbu Line, it's investigated the extensibility of rail freight with the relation of rail fare discount and examined the necessity of pilot business to the Kyungjeon Line which was expected comparatively lower cost. If the DST system is introduced to the Kyungjeon Line, the cost of mass transportation can be much lower and then the comparativeness of rail transportation will be increased, therefore logistic companies can have some margin additionally. In the result of survey to the related companies, if rail transportation fare is 37.7 % cheaper than current road transportation fare, the modal shift can be transferred by maximum 100%.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.4
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• pp.95-104
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• 2006

The DMZ is a 248km long thin green line which has various landscapes of fields, hills and mountains. This study focused on western part of DMZ and vicinity which consist of abandoned rice paddy, wetlands and fields. The main purpose of this study is to detect the vegetation vitality from the western part of MDL to DMZ vicinity and identify and quantify ecological buffer(ecotone) width adopting logistic function derived from 'Vegetation Index-distance curve' using an Landsat ETM+ image acquired on June of 2002. Green leaf vegetation was quantified to identify the ecotone buffer in western DMZ and vicinity(civilian control area: CCA) using Transformed Vegetation Index(TVI) which is one of common measurement among various indices. Vegetation measurement from Military Demarcation Line(MDL) to vicinity area was investigated at 500m intervals to 10kms of southern and northern part of western DMZ and vicinity. The Logistic function models the sigmoid curve of growth with three stages of growth of initial competition and maturity. In the TVI-distance logistic curve, the maturity is high vegetation vitality, the competition is vitality changing, and the initial is low vitality. In the TVI-distance curve, maturity area of high TVI value is core area for ecological conservation, and the competition area between inflection points can be an ecotone(ecological buffer). In case of southern part, maximum TVI value is 221.92 and minimum is 207.16, and maximum TVI of northen part is 215.32 and minimum is 188.35. That means forest devastation of north Korean part of DMZ and vicinity is severer than that of south Korea. The width of core area for ecological conservation is 2,311m, and ecotone in the southern part is 5,339m, so minimum width from MDL for ecological conservation can be computed as 7,651m. In case of Northern part, the width of core area is 1,841m, and ecotone buffer is 5,014m, so ecological conservation width can be estimated as 6,855m. In case of northen part, width of estimated core area is less than that of DMZ width, which means ecological disturbance is very severe in northern part of western DMZ.

• Korean Journal of Community Nutrition
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• v.19 no.1
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• pp.84-94
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• 2014

Periodontal disease is one of the most common chronic inflammatory diseases in the oral cavity, and this is the leading cause of loss of teeth. Studies on the association between diet and periodontal diseases are very limited. The purpose of this study was to investigate the association between food and nutrient intakes and the prevalence of periodontitis. Subjects were 13,391 adults participating in the 2008-2010 Korea Health and Nutrition Examination Survey. Periodontitis was diagnosed by dentists using the Community Periodontal Index. Nutrient intakes were estimated by the 24-hour dietary recall. Consumption frequencies of foods were from the food frequency questionnaire. Subjects were categorized into 'smoking' or 'non-smoking' groups. Multiple logistic regression analysis was applied to determine the association between diet and periodontitis. The proportions of subjects having periodontitis were 26% in the non-smoking group and 37.5% in the smoking group. In the nonsmoking group, intakes of fruits, dairy products, green tea, energy and vitamin C were inversely associated with the prevalence of periodontitis, but fish and coffee intakes were positively associated with the prevalence of periodontitis after adjusting for covariates. In the smoking group, protein and retinol intakes were inversely associated with the prevalence of periodontitis after adjusting for covariates. These results suggest that certain food and nutrient intakes such as fruits, dairy products, green tea, vitamin C, protein, or retinol intakes may affect the prevalence of periodontitis among Korean adults. Further studies are required to confirm these findings in other research settings.

• Journal of Korea Port Economic Association
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• v.27 no.3
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• pp.147-159
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• 2011

The purpose of the study is to propose a policy implication of urban logistics in the Incheon metropolitan city. To attain the aim, it reviews new characteristics that Logistics Policy Fundamental Law(LPFL) published by government 2009 suggests and studies the previous papers like Logistic Fundamental Plan(LFP) of other metropolitan cities. After that it proposes a policy implication through benchmarking of urban logistics plan at Tokyo city not only located at a capital area at Japan but also including port and airport. The results are as follows. Firstly, field survey studies of the "LFP" every five years will need to keep pace with "Urban Fundamental Plan"(UFP) having designed to all cities legally every ten years. Secondly, Incheon will be required to create value-added logistics, making best use of third-party logistic companies to small-medium sized businesses along with the age of green. Thirdly, LFP needs to be performed through a mutual cooperation and adjustment among Incheon, Gyeonggi-do and Seoul and in this regions eco-friendly companies performing related logistic activities have to be followed executive and financial supports. Lastly, it will be obliged to develop a evaluation management index to understand the advancement level through a feedback system.

• Journal of Veterinary Clinics
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• v.39 no.5
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• pp.199-206
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• 2022

Postpartum diseases should be predicted to prevent productivity loss before calving especially in organic dairy farms. This study was aimed to investigate the incidence of postpartum metabolic diseases in an organic dairy farm in Korea, to confirm the association between diseases and prepartum blood biochemical parameters, and to evaluate the accuracy of these parameters with a receiver operating characteristic (ROC) analysis for identifying vulnerable cows. Data were collected from 58 Holstein cows (16 primiparous and 42 multiparous) having calved for 2 years on an organic farm. During a transition period from 4 weeks prepartum to 4 weeks postpartum, blood biochemistry was performed through blood collection every 2 weeks with a physical examination. Thirty-one (53.4%) cows (9 primiparous and 22 multiparous) were diagnosed with at least one postpartum disease. Each incidence was 27.6% for subclinical ketosis, 22.4% for subclinical hypocalcemia, 12.1% for retained placenta, 10.3% for displaced abomasum and 5.2% for clinical ketosis. Between at least one disease and no disease, there were significant differences in the prepartum levels of parameters like body condition score (BCS), non-esterified fatty acid (NEFA), total bilirubin (T-bil), direct bilirubin (D-bil) and NEFA to total cholesterol (T-chol) ratio (p < 0.05). The ROC analysis of each of these prepartum parameters had the area under the curve (AUC) <0.7. However, the ROC analysis with logistic regression including all these parameters revealed a higher AUC (0.769), sensitivity (71.0%), and specificity (77.8%). The ROC analysis with logistic regression including the prepartum BCS, NEFA, T-bil, D-bil, and NEFA to T-chol ratio can be used to identify cows that are vulnerable to postpartum diseases with moderate accuracy.

• Journal of Korean Society of Rural Planning
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• v.19 no.2
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• pp.107-120
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• 2013

A lot of rural development projects have been planned and implemented for revitalizing rural areas in South Korea. However, it is not easy to properly evaluate and quantitatively analyze project outcomes. For this reason only selected regions have been evaluated for rural projects by government agencies. In this study, we analyzed the purpose and the contents of the Rural Village Development Project (RVDP) and Green Tourism Village Project (GTVP) to find indicators for evaluating results of rural projects using logistic regression analysis. Outputs of this study show that RVDPs increase regional population and GTVPs positively affect the sales of agricultural products. We also estimated the spatial distribution of project effects through spatial autocorrelation analysis and local-spatial autocorrelation analysis. Results show that the Moran's I values for the proportion of farmers with avocational jobs, product sales changes, and population growth in Jeol-La province are positive and the biggest one is population growth. Especially, key areas of agricultural product sales are widely distributed.

• Earthquakes and Structures
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• v.3 no.1
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• pp.1-15
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• 2012

An empirical predictive relationship correlating bracketed duration to earthquake magnitude, site-to-source distance, and local site conditions (i.e. rock vs. stiff soil) for stable continental regions of North America is presented herein. The correlation was developed from data from 620 horizontal motions for central and eastern North America (CENA), consisting of 28 recorded motions and 592 scaled motions. The bracketed duration data was comprised of nonzero and zero durations. The non-linear mixed-effects regression technique was used to fit a predictive model to the nonzero duration data. To account for the zero duration data, logistic regression was conducted to model the probability of zero duration occurrences. Then, the probability models were applied as weighting functions to the NLME regression results. Comparing the bracketed durations for CENA motions with those from active shallow crustal regions (e.g. western North America: WNA), the motions in CENA have longer bracketed durations than those in the WNA. Especially for larger magnitudes at far distances, the bracketed durations in CENA tend to be significantly longer than those in WNA.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.5
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• pp.2291-2297
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• 2012

Objective: Gastric cancer is an important public health problem in the world and Turkey. In addition to Helicobacter pylori (H. pylori), smoking, alcohol consumption and family history, certain dietary factors have been associated with its occurrence. The impact of dietary habits and life-style factors on the risk of gastric cancer in Turkey were evaluated in this study. Design: A questionnaire was applied to 106 patients with gastric adenocarcinoma and 106 controls without cancer matched for age (range 28-85 years) and gender selected from a hospital based population. Adjusted odds ratios (ORs) and 95% confidence intervals (CI) were calculated with logistic regression analysis. Results: The incidence of H. pylori was 81.3% in patients. Frequent consumption of salty dishes, very salty foods like pickles, soup mixes, sausages, foods at hot temperature (ORs = 3.686, 7.784, 5.264, 3.148 and 3.273 respectively) and adding salt without tasting (OR = 4.198) were associated with increased gastric risk. Also heavy smoking and high amount of alcohol consumption (p = 0.000) were risk factors. Frequent consumption of green vegetables, onion, garlic and dried fruits (ORs = 0.569, 0.092, 0.795 and 0.041) was nonsignificantly associated with decreased risk. Conclusion: Improved dietary habits, reducing salt consumption and eradication of H. pylori infection may provide protection against gastric cancer in Turkey.