• KIEAE Journal
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• v.15 no.4
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• pp.105-110
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• 2015

Purpose: This study aimed at finding the optimal input variables of the artificial neural network-based predictive model for the optimal controls of the indoor temperature environment. By applying the optimal input variables to the predictive model, the required time for restoring the current indoor temperature during the setback period to the normal setpoint temperature can be more precisely calculated for the cooling season. The precise prediction results will support the advanced operation of the cooling system to condition the indoor temperature comfortably in a more energy-efficient manner. Method: Two major steps employing the numerical computer simulation method were conducted for developing an ANN model and finding the optimal input variables. In the first process, the initial ANN model was intuitively determined to have input neurons that seemed to have a relationship with the output neuron. The second process was conducted for finding the statistical relationship between the initial input variables and output variable. Result: Based on the statistical analysis, the optimal input variables were determined.

• Korean System Dynamics Review
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• v.13 no.2
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• pp.47-71
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• 2012

The purpose of this research is the examination of validity of data as well as simulation model, i.e. to simulate the real data in the SD model with the least error using the adjustments for the faithful reflection of real data to the simulation. In general, SD programs (e.g. VENSIM) utilize the Euler or Runge-Kutta method as an algorithm. It is possible to reflect the trend of real data via these two estimation methods however can cause the validity problem in case of the simulation requiring the accuracy as they have endogenous errors. In this article, the future population estimated by the Korea National Statistical Office (KNSO) to 2050 is simulated by the aging chain model, dividing the population into three cohorts, 0-14, 15-64, 65 and over cohorts by age and offering the adjustments to them. Adjustments are calculated by optimization with three different methods, optimization in EXCEL, manual optimization with iterative calculation, and optimization in VENSIM DSS, the results are compared, and at last the optimal adjustment set with the least error are found among them. The simulation results with the pre-determined optimal adjustment set are validated by methods proposed by Barlas (1996) and other alternative methods. It is concluded that the result of simulation model in this research has no significant difference from the real data and reflects the real trend faithfully.

• Journal of Soil and Groundwater Environment
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• v.26 no.6
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• pp.186-195
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• 2021

In Korea, groundwater quality is monitored through National Groundwater Quality Monitoring Network (NGQMN) administered by Ministry of Environment. For a given contaminant, compliance to groundwater quality standards is assessed on a annual basis by monitoring the number of incidents that concentration exceeds the regulatory limit. However, this approach provides only a fractional information about groundwater quality degradation, and more crucial information such as location and severity of the contamination cannot be obtained. For better groundwater quality management on a watershed, a more spatially informative and intuitive method is required. This study presents two statistical methods to convert point-wise monitoring data into information on groundwater quality status of a watershed by using a proposed grading scale. The proposed grading system is based on readily available reference standards that classify the water quality into 4 grades. The methods were evaluated with NO₃^-, Cl^-, and total coliform data in Geum River basin. The analyses revealed that groundwater in most watersheds of Geum River basin is good for domestic or/and drinking with no treatment. But, there was notable quality degradation in Bunam seawall and So-oak downstream standard watersheds contaminated by NO₃^- and Cl^-, respectively.

• The Korean Journal of Emergency Medical Services
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• v.23 no.2
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• pp.87-97
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• 2019

Purpose: This study aimed to compare and analyze statistical data on 119 ambulance runs and ambulance crew, which are the components of the emergency medical services system in Korea and Japan. Methods: Data from National Fire Agencies of both Korea and Japan were collected and statistically compared. Results: With regard to the ratio of 119 ambulance runs, Korea's ratio has been gradually and continuously growing beyond that of Japan (Korea 4708.11, Japan 4706.47) since 2014. The ratio of firefighting ambulances in Korea was 2.59 ($2.59{\pm}0.10$), and was 4.76 ($4.76{\pm}0.12$) in Japan. The ratio of 119 ambulance crews in Korea was 15.55 ($15.55{\pm}2.03$), and was 47.24 ($47.24{\pm}1.06$) in Japan. Among the ambulance crews, the ratio of paramedics was 33.81 ($33.81{\pm}5.85$) in Korea and was 38.86($38.86{\pm}4.10$) in Japan. Conclusion: The ratio of 119 ambulance runs in Korea has already exceeded that of Japan, but the numbers of 119 ambulance crews and paramedics qualified for special emergency treatment are still insufficient. Therefore, supply and demand policy that promotes the development of the firefighting ambulance service system is necessary.

• Journal of Society of Preventive Korean Medicine
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• v.22 no.3
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• pp.11-19
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• 2018

Objectives : The aim of this study is to investigate the current research trend of herbal medicine based on the published articles in pharmacoepidemiologic journals. Methods : A total of 3 electronic journals, Pharmacoepidemiology and Drug Safety(PDS), Drug Safety and Journal of Pharmacoepidemiology and Risk Management(JPERM) from January 2013 to August 2018 were used for searching articles about herbal medicine. Selected articles were reviewed and classified under 5 categories-collection of adverse events in herbal medicine, statistical modeling and methodology, pharmaco-epidemiologic outcome study, drug utilization review(DUR), risk management system and regulation. Results : A total of 8 articles were finally included for analysis. 2 articles were categorized in collection of adverse events in herbal medicine, 1 was statistical modeling and methodology, 2 were pharmacoepidemiologic outcome study and 3 were risk management system and regulation. There was no article in DUR. And then pharmacoepidemiologic research trends of herbal medicine were summarized in classification of 5 categories. Conclusions : To sum up with these 8 articles of herbal medicine in pharmacoepidemiologic journals, herbal medicine was of interesting concern among researchers. The need for research on safety and risk management of herbal medicine is steadily increasing, pharmacoepidemiologic research about herbal medicine must be activated in Korea.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.323-330
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• 2022

Safety accidents in university laboratories are constantly occurring due to various chemical, physical, and biohazard risk factors. In this study, the trend of accident occurrence and correlations between factors were derived through statistical and cross-analysis of 192 accident cases in university labs between 2016 and 2020. Directions and strategies were prepared from the correlations of major factors, and guidelines for improvement of the laboratory safety management system were suggested by comparing and analyzing existing policy directions for laboratory accidents.

• Journal of Astronomy and Space Sciences
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• v.29 no.4
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• pp.397-405
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• 2012

Astronomical Observations at Chungbuk National University Observatory (CBNUO) with an 1 m telescope have begun since April 2008, and Near-Earth Space Survey observations also have been started since November 2010, with a 0.6 m wide field telescope developed by Korea Astronomy and Space Science Institute. To improve observational efficiency, we developed a weather monitoring system enabling automatic monitoring for the weather conditions and checking the status of the observational circumstances, such as dome status. We hope this weather monitoring system can be helpful to more than 100 Korean domestic observatories, including public outreach facilities. In this paper, we present the statistic analysis of the weather conditions collected at CBNUO for 3 years (2009- 2011) and comparisons were made for clear nights between using only humidity data and both humidity and cloud data.

• Health Policy and Management
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• v.15 no.4
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• pp.46-64
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• 2005

This study was conducted to verify the current criteria and classification system used to determine specialized general hospitals status. In this study, we proposed a new classification system which Is simpler and more convenient than the current one. In the new classification system clinical procedure was chosen as the unit of analysis in order to reflect all the resource consumption and the complexities and degree of medical technologies in determining specialized general hospitals. We developed a statistical model and applied this model to 117 general hospitals which claim their national insurance through electronic data interchange(EDI). Analysis based on 984 clinical procedures and medical facilities' characteristic variable discriminated specialized general hospital in present without misclassification. It means that we can determine specialized general hospital's permission In new way without using the current complicated criteria. This study discriminated specialized general hospital by the new proposed model based on clinical procedures provided by each hospital. For clustering the same types of medical facilities using 984 clinical procedures, we executed multidimensional scale analysis and divided 117 hospitals into 4 groups by two axises : a variety of procedure and the Proportion of high technology Procedure. Therefore, we divided 117 hospitals into 4 groups and one of them was considered as specialized general hospital. In discriminating analysis, we abstracted proportion of 16 clinical procedures which effect on discriminating the specialized general hospital in statistical system also we identify discriminating function which include these variables. As a result, we identify 2 discriminating functions, one is for current discriminating system and the other two is for new discriminating system of specialized general hospital.

• Health Policy and Management
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• v.14 no.2
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• pp.78-98
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• 2004

The purpose of this study was to categorize the contribution evasion and develop the expected models for contribution arrears in National Health Care System. The modified logistic regression model in non-payments was used as logistic regression model based on the statistical method. By using this model, we arranged non-payment types and typical branches those are appeared by statistical technique. First fact, sex and age branches those are able to take a part in economy had effect mostly. Also they had difference in non-payment probability by existence of their incomes and property. Especially people who didn't have their own house and car were appeared in high non-payment probability, disease and reduction characteristic(rare diseases, reduction of seniors, handicaps, numbers of medical treatments) didn't effect much in probability. The reason for some characteristic of non-payment which is higher than the correct threshold value of Logistic Regression Model (a suggested model for predicting non-payment)'s distribution of probability was mostly moral hazard. Living difficulty was the bigger reason for non-payment, but moral slackening was the bigger reason for non-payment. But it is careless to decide that moral hazard is just the reason, there is a necessity to examine on the side of sociology based in family. By the reason, the member's non-payment reason can be classified by economy, population, and psychology, but there was a comprehension that losing of work desire could be one reason. So we analyzed informations for composition of family of members. In conclusion, we grasped that family conflict makes non-payment and conversion of member in the National Basic Livelihood Protection System difficult.

• The Korean Journal of Applied Statistics
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• v.18 no.1
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• pp.147-158
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• 2005

Most of the statistical models that real data can be applicable are static in nature, and thus it is not possible to analyze the effect of variations in the real world over time. Usual specification of the models does not produce the length and the time path of the effect even if the effect of an exogenous variation continues for periods of time. In this study, deriving the dynamic inherence from the static structure of the linear model for better utilization, we attempt to apply actual data to compare and analyze the long-run effect of variations in the market variables between the related markets by formulating a simultaneous equation system. Accordingly, it is proved to be possible to obtain efficient analytical results and to derive various useful implications.