• Journal of Korea Water Resources Association
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• v.45 no.1
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• pp.101-111
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• 2012

In this paper, the feedback loop mechanisms among the operational indices and exogenous variables of a sewerage system that are inherent in the operation and maintenance of a sewerage system were identified using the System Dynamics (SD) modeling methodology. The identified feedback loops were used to develop a SD computer simulation model that can be used to predict future operational conditions of a sewerage system and identified the efficient ways of operation. The data of Busan metropolitan city sewerage system was applied to verify the developed SD model and predict future operational conditions of the system. As a result, it was predicted that sewage treatment efficiency, volume of sewage treatment and cost recovery rate will be gradually increased, whereas service rate which was already very close to the target will remain almost the same as the current value. Furthermore, sensitivity analysis concerning some operational indices was performed in order to discover the policy leverage. As a result, it was found that the exogenous variables related to the pipe maintenance had a great effect on facility using rate, volume of sewage treatment as well as sewage treatment efficiency.

• Korean Journal of Health Education and Promotion
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• v.31 no.5
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• pp.81-95
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• 2014

Objectives: The purpose of this study was to apply participatory action-oriented training (PAOT) principle for the management of metabolic syndrome and to assess its effectiveness in the workplace. Methods: The metabolic syndrome management program applying participatory action-oriented training (PAOT) principle is constructed action checklist, Group discussion, self-creation of an action plan, after 3 months, 6 months, 1 year, the practice carried out check up and encourage practice activity. Results: The seventy-seven workers who participated in the metabolic syndrome management program made a total of 246 action plans, 3.8 action plans per person and 234 action plans were achieved after one year, so that 81.0% of action plans have been achieved. After 1 year, in the intervention group, systolic blood pressure (SBP) and diastolic blood pressure (DBP), body mass index (BMI), the risk factors score decreased statistically significant, and metabolic syndrome prevalence decreased 54.8%. whereas the control group also showed a significant decreased in the mean systolic and diastolic blood pressure, the risk factors score. but, low-density lipoprotein (LDL) was significantly increased. Conclusions: To improve the effectiveness of metabolic syndrome management program applying participatory action-oriented training (PAOT) principle, the need to continues implementing programs and analysis of the long-term effects are required. Participatory action-oriented training (PAOT) principle can applying without cost and time, the human burden for the prevention and management of chronic diseases such as metabolic syndrome.

• The KIPS Transactions:PartD
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• v.17D no.1
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• pp.1-8
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• 2010

Association rule mining techniques enable us to acquire knowledge concerning sales patterns among individual items from voluminous transactional data. Certainly, one of the major purposes of association rule mining is utilizing the acquired knowledge to provide marketing strategies such as catalogue design, cross-selling and shop allocation. However, this requires too much time and high cost to only extract the actionable and profitable knowledge from tremendous numbers of discovered patterns. In currently available literature, a number of interest measures have been devised to accelerate and systematize the process of pattern evaluation. Unfortunately, most of such measures, including support and confidence, are prone to yielding impractical results because they are calculated only from the sales frequencies of items. For instance, traditional measures cannot differentiate between the purchases in a small basket and those in a large shopping cart. Therefore, some adjustment should be made to the size of market baskets because there is a strong possibility that mutually irrelevant items could appear together in a large shopping cart. Contrary to the previous approaches, we attempted to consider market basket's size in calculating interest measures. Because the devised measure assigns different weights to individual purchases according to their basket sizes, we expect that the measure can minimize distortion of results caused by accidental patterns. Additionally, we performed intensive computer simulations under various environments, and we performed real case analyses to analyze the correctness and consistency of the devised measure.

• Journal of the Society of Disaster Information
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• v.15 no.4
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• pp.548-559
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• 2019

Purpose: Analysis method of V2I data driven motorway service area usage behavior to cope with manpower survey. Method: Segmentation of traveling state group and boundary using the distribution characteristics of traveling speed data of individual vehicles. Result: As a result of the verification, the use rate of resting places in lunchtime surged, and the boundary between the distribution status of the traffic speed data was clearly or unclear. Conclusion: The effect of the cost reduction is big because it can cope with the use of rest area survey by manpower and there is no limit in the time and space range of investigation. The dynamic utilization rate of each time sequence, such as a service area/drowsiness shelter/simple service area, with a V2I system, can be calculated. Identify illegal parking on highway section. Identify the unexpected situation in the road section. Identify the real-time service area utilization rate and congestion information.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.7
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• pp.2925-2930
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• 2011

A vehicle fuel economy is very important issue in the view of fuel cost and environmental regulation. The fuel economy is much improved according to the development of electric, electronic and mechanical technology, but up to now the measurement of it tests the given mode(LA-4, FTP-75, etc) within computer simulation program and engine dynamometer. This fuel economy is different with it of real road. The one of main reason is not considered the gradient of the road. To estimate the effects of fuel economy at highway with gradient in this paper, we measure the amount of fuel consumption and calculate the fuel economy of it with running the Youngdong highway with high gradient. Also this paper analysis and compares the fuel economy with gradient and without gradient when the vehicle runs the same driveway. Then we calculate the total energy created the difference of fuel consumption amount of the two cases and calculate the consumpted energy by tire driving force from the torque and power of engine in the simulation. This paper verifies the relation of the driving force and the total energy by creating the difference of fuel consumption amount. This paper also proposes the method of fuel economy improvement despite of gradient at the result.

• Journal of Soil and Groundwater Environment
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• v.19 no.1
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• pp.34-45
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• 2014

A variety of physical, chemical, and microbiological techniques have been developed to deal with soil and groundwater contamination. However, in the presence of the large portion of soil micro-environments, contaminant rebound and/or tailing have been frequently reported. Case study of total petroleum hydrocarbons (TPH) removal by full-scale land farming showed that contaminant rebound and/or tailing occurred in 9 out of total 21 cases and subsequently resulted in problems of a long term operation to satisfy TPH guidelines of contaminated soil and groundwater. The main cause of contaminant rebound and tailing is considered to be the strong interactions between contaminants and micro-environments including micro-particles, micro-pores, and organic matter. Thus, this study reviewed the effects of soil micro-environments of soil and groundwater on the removal efficiency for both heavy metals and petroleum contaminants. In addition, the various methods of sampling, analysis, and assessment of soil micro-environments were evaluated. Thorough understanding of the effects of soil micro-environments on contaminant removal will be essential to achieve a cost-effective and efficient solution to contaminated sites.

• Journal of the Korean Society of School Health
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• v.8 no.1
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• pp.143-154
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• 1995

Korea has been recently reducing the quality of life as well as rising medical cost because of the increase of chronic diseases. But we can prevent those chronic diseases through the improvement of environment or life style. We evaluated the educational effectiveness of chronic diseases(hypertention, diabetes, cancer, stroke and other chronic diseases) designed to increase the knowledge, attitude and practice of chronic diseases among university students. Between August 1994 and November 1994, we implemented chronic diseases prevention instruction in intervention students; unmatched control students were selected in same university. We conducted pre- and post-intervention surveys both intervention and control students with self-reported questionnaires(50 items). We assigned score(0-4 points) to items and conducted a analysis of covariance(ANCOVA) with sex, grade and economic status as the covariate, using the SAS PC computer statistical package. And we culculated odds ratio with safety scores between intervention and control students. The results of this study were followed. 1. In demographic characteristics of subjects both pre- and post intervention, we found no significant differences in intervention and control students at religion, father's education, mother's education, mother's occupation and type of residence(p>0.05), but we found significant differences at sex(p<0.001), grade(p<0.001) and economic status(p<0.05). 2. The sex, grade and economic status-adjusted mean prevention knowledge scores for diabetes and stroke increased from the pre- to post-survey in the intervention students(p<0.001), but control students did not increased(p>0.05). As odds ratios in knowledge were below 1, the knowledge of intervention students were higher than control students. 3. The attitudes for general adult health increased from the pre- to post-survey in the intervention students(p<0.05), but control students did not increased(p>0.05). As odds ratios in attitudes were approximately 1, we can not say effectiveness in intervention students 4. The pratices for cancer and stroke increased from the pre- to post-survey in both the intervention and control students(p<0.001). Also odds ratio of hypertention was 0.91, and that of stroke was 1.14. 5. Health related behaviors did not increased from the pre- to post- survey in both the intervention and control students(p>0.05). But odds ratio of drinking was 0.76 and that of body weight was 1.21. 6. Health status did not increased from the pre- to post- survey in both the intervention and control students(p>0.05). As odds ratio of health status was 1.09, prevention education was not effect in intervention students We would like to recommend as follows; 1. University students must learn about prevention of chronic diseases. Because the knowledge of invetervention students was higher than that of control students. 2. The prevention education of chronic diseases should be taught from primary school. 3. Adult health education for university students must be practiced continuously. Education period(l5 weeks) in this study was not complete. 4. The evaluation of chronic diseases was conducted real measurement(such as BP check) as well as self reported-survey. 5. Educational materials(video tape, pamphlet) related the prevention of chronic diseases should be developed at national level. And we must easely use those materials. 6. The prevention education of chronic diseases should be made through mass media as well as school education.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.107-116
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• 2002

Crash Cushion is a kind of safety facilities on roadside which acts the role of absorbing impact energy when vehicles are driven out of normal route such as Gore area of freeway off ramp. Criteria for severity index considering accident occurrence possibility are needed to have strong effect on installing the facilities. However, present criteria for establishing crash cushion design do not include such processes. Therefore, the paper presents two kinds of study to develop criteria for severity index. First of all, development of accident forecasting model on freeway off ramp is presented. The module is a relationship between accidents and road environment by negative binomial distribution (NB) which is called to reflect very well quality of accidents at Gore of crash cushion installed freeway Secondly, freeway exiting behavior model is developed because the human factor is the most important one. However, many literatures have shown between road environment and accidents which are more quantitative than human factor. The study supposed advanced process steps on actual freeway and analysed correlation between variables and accidents. The criteria for severity index is presented to determine whether to install or not by benefit cost analysis for each module. The standard for severity index will help to determine whether to install the crash cushion or not and to estimate severity for freeway and off ramp.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.221-227
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• 2016

The purpose of this study is to investigate the effect of social factors and social stress with respect to alcohol consumption for university students and to provide basic data in efforts to develop educational method that teaches how to decrease alcohol consumption and deny demanding drinking. Questions concerning typical features and social stress from drinking were revised through 300 university students' self-recording surveys between April 8 and 9 in 2015. It consisted of 10 questions using a 4-point Likert scale. Moreover, the reliability of tool was Cronbach ${\alpha}=.82$. We used SPSS 18.0 and conducted frequency, ${\chi}^2$ and path analysis. If the frequency of drinking (B=.206, p<.001) gets low and the social stress from drinking is low (B=-.397, p<.001), the amount of drinking increases, particularly for men more than women (B=.169, p<.05). For women more than men (B=.274, p<.01), if monthly income is high (B=.178, p<.05) and stress from drinking is low (B=-.349, p<.01), the frequency of drinking is high. If the culture of practice in drinking has not formed voluntarily through education or publication, legal restriction that increases the cost of drinking has to be established, like smoking, to reduce the volume of drinking and promote moderation in drinking. The publication and education that teaches drinking leads to bad situations have to be conducted, much like the education programs involved for smoking. Also, discrimination of non-drinker has to be removed with the change of culture to reduce the stress by drinking.

• Korean Journal of Remote Sensing
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• v.21 no.4
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• pp.287-302
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• 2005

Digital Elevation Models (DEMs) were generated by ERS-l/2 and JERS-1 SAR interferometry in Daejon area, Korea. The quality of the DEM's was evaluated by the Ground Control Points (GCPs) in city area where GCPs were determined by GPS surveys, while in the mountain area with no GCPs, a 1:25,000 digital map was used. In order to minimize errors due to the inaccurate satellite orbit information and the phase unwrapping procedure, a Differential InSAR (DInSAR) was implemented in addition to the traditional InSAR analysis for DEM generation. In addition, DEMs from GTOPO30, SRTM-3, and 1:25,000 digital map were used for assessment the resolution of the DEM generated from DInSAR. 5-6 meters of elevation errors were found in the flat area regardless of the usage and the resolution of DEM, as a result of InSAR analyzing with a pair of ERS tandem and 6 pairs of JERS-1 interferograms. In the mountain area, however, DInSAR with DEMs from SRTM-3 and the digital map was found to be very effective to reduce errors due to phase unwrapping procedure. Also errors due to low signal-to-noise ratio of radar images and atmospheric effect were attenuated in the DEMs generated from the stacking of 6 pairs of JERS-1. SAR interferometry with multiple pairs of SAR interferogram with low resolution DEM can be effectively used to enhance the resolution of DEM in terms of data processing time and cost.