• Journal of Ocean Engineering and Technology
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• v.34 no.6
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• pp.461-468
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• 2020

This study examined how national research and development (R&D) in the domain of logistics has changed recently in the Republic of Korea. We conducted basic statistical analysis and social network analysis on 5,327 logistics-related R&D projects undertaken during 2005-2019. Data for performing these analyses were collected from the R&D database of the National Science and Technology Information Service (NTIS). By constructing a co-occurrence matrix with keywords, we conducted degree and betweenness centrality analysis and visualized the network matrix to display a cluster map. This study presents our observations related to the following findings: (1) the chronical trends of logistics R&D, (2) focused fields of logistics R&D, (3) the relations among keywords, and (4) the characteristics of logistics R&D. Finally, we suggest policy implications to boost and diversify logistics R&D.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.352-361
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• 2003

We have evaluated the extent of saltwater intrusion from electrical resistivity distribution in a coastal aquifer system in the southeastern part of Busan, Korea. This aquifer system is divided into four layers according to the hydrogeologic characteristics and the horizontal extent of intruded saltwater is determined at each layer through the geostatistical interpretation of electrical resistivity data. In order to define the statistical structure of electrical resistivity data, variogram analysis is carried out to obtain best generalized covariance models. IRF-k (intrinsic random function of order k) kriging is performed with covariance models to produce the plane of spatial mean resistivities. The kriged estimates are evaluated by cross validation to show a good agreement with the true values and the statistics of cross validation represented low errors for the estimates. In the resistivity contour maps more than 5 m below the surface, we can see a dominant direction of saltwater intrusion beginning from the east side. The area of saltwater intrusion increases with depth. The northeast side has low resistivities less than 5 ohm-m due to the presence of saline water in the depth range of 20 m through 70 m. These results show that the application of geostatistical technique to electrical resistivity data is useful for assessing saltwater intrusion in a coastal aquifer system.

• Journal of the Korean Solar Energy Society
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• v.30 no.2
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• pp.1-9
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• 2010

This study has intended to analyze citizen's recognition on Photovoltaic (PV) System Supply Policy in Korea. To reach this goal, this study has employed a survey method and statistical analysis. We have asked 140 citizens knowing the policy to some degree to answer questionnaires including various contents related to PV supply policy driven by central government of Korea. The contents of questionnaires consist of three parts: 1) supply policies, 2) PV system and 3) expected effect from the policy. To verify any differences among the characteristics of respondents, ANOVA (Analysis of Variance) was carried out in 95% confidence level. This study has found the following results: 1) most citizens were positive about the 'Photovoltaic System Supply Policies'; 2) most citizens anticipated the policy would be helpful to cope with the environmental problems and energy crisis and 3) there exit subtle differences between residents according to the respondent's characteristics such as sex, age, occupation, and housing type.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.4
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• pp.133-141
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• 2023

Approximately 40,000 elevators are installed every year in Korea, and they are used as a convenient means of transportation in daily life. However, the continuous increase in elevators has a social problem of increased safety accidents behind the functional aspect of convenience. There is an emerging need to induce preemptive and active elevator safety management by elevator management entities by strengthening the management of poorly managed elevators. Therefore, this study examines domestic research cases related to the evaluation items of the elevator safety quality rating system conducted in previous studies, and develops a statistical model that can examine the effect of elevator maintenance quality as a result of the safety management of the elevator management entity. We review two types: odds ratio analysis and logistic regression analysis models.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.59-59
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• 2012

Self-consistent mathematical model of the exotic object OTJ 071126+440405= CSS 081231:071126+440405 is discussed. The system was discovered as a polar at the New year night 31.12.2008/01.01.2009 by D.Denisenko (VSNET Circ), and we have initiated an international campaign of photometric and polarimetric observations of this object (totally -80 runs in Ukraine, Korea, Slovakia, Finland, USA) as a part of the "Inter-Longitude Astronomy" (ILA) project on monitoring of variable stars of different classes (Andronov et al., 2003). Here we present the geometrical and physical model of the system in the low luminosity state and in the intermediate luminosity state as well as in the high luminosity state. As the system is of -20 mag at minimum, no spectral observations were made to determine parameters of the red dwarf. From the statistical relationship, the mass of the red dwarf is estimated to be -0.165 solar masses, for the white dwarf (from eclipse duration) - from 0.5 to 1.76 solar masses. As the system resembles ER UMa in some characteristics, the lower value may be assumed. The inclination of the system and other physical parameters are estimated. The object is an excellent laboratory to study multiple physical processes in the magnetic systems.

• Journal of the Korea Society of Computer and Information
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• v.22 no.9
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• pp.99-105
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• 2017

In this paper, we propose to design and implement the database management system for analyzing vehicle accidents through utilizing integration of the public big data. And the paper aims to provide valuable information for recognizing seriousness of the vehicle accidents and various circumstances at the accident time, and to utilize the produced information for the insurance company policies as well as government policies. For analysis of the vehicle accidents the system utilizes the integrated big data of National Indicator System, the Meteorological Office, National Statistical Office, Korea Insurance Development Institute, Road Traffic Authority, Ministry of Land, Infrastructure and Transport as well as the National Police Agency, which differentiates this system from the previous systems. The system consists of data at the accident time including weather conditions, vehicle models, age, sex, insurance amount etc., by which the database system users are able to obtain the integral information about vehicle accidents. The result shows that the vehicle accidents occur more frequently in the clear weather conditions, in the vehicle to vehicle conditions and in crosswalk & crossway. Also, it shows that the accidents in the cloudy weather leads more seriously to injury and death than in the clear weather. As well, the vehicle accident information produced by the system can be utilized to effectively prevent drivers from dangerous accidents.

• Journal of Korean Society on Water Environment
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• v.32 no.3
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• pp.318-324
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• 2016

The significance of an integrated environmental management system implementation can be summarized into three sections. The first is that the paradigm of a permit system will be changed from the existing media-specific permits to cross-media permits. In the near future, the cross-media license will be granted based on the diagnostic results of the plant. The second is that it will be established through a social concensus, i.e., consultations with stakeholders and direct participation in the system design process of stakeholders. The third is that it will have flexibility in its operating system. In the near future, it will be possible to management an environment through its industrial workplace itself and determine if emission standards are being complied with or not through statistical methods. In addition there is also an urgent need for complementary parts in order to enhance the driving force of the integrated environmental management system which is based on transparency, reliability and flexibility. In other words, it is necessary to continuously promote in order to diffuse consensus and increase an understanding of implementation through an integrated environmental management system. It is also necessary to establish a new organization and educate authorized representatives so that they have the tools to smoothly perform the system.

• Journal of Environmental Health Sciences
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• v.46 no.2
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• pp.232-244
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• 2020

Objectives: The purpose of this study is to develop a management system for the safe handling of chemicals and related health management based on reporting under the Chemical Control Act (CCA). It is used to search handling information by constructing data linked to the name of companies, chemicals, products, etc. Methods: Due to the differences in submission periods for each reporting regulation of the Chemical Control Act, the data used is as follows: A statistical survey collected 26,222 companies in 2014 and 2016, Pollutant Release Transfer Registers (PRTR) collected 4,234 companies in 2015-2017, performance reports by handlers of hazardous chemical substances collected 14,658 companies in 2016-2018, and declarations for import of toxic chemicals collected 892 companies in 2016-2017. The total information on 36,080 companies is standardized based on company ID, name, business registration number, address, and more. The data were classified into information such as company, chemical, and product name and amounts handled and released, and then extracted according to criteria to establish relationships among classified information. Results: A search service was developed for handling information on chemical substances for reporting data by linking four reporting data: statistical survey, PRTR, performance report by handler of hazardous chemical substances, and declaration for import of toxic chemicals under the CCA. It was composed of five menus to search by regulation type, reporting regulation, companies and chemicals, and system management. Conclusion: It is necessary to use data linked by company, region, and chemical to respond and to prevent chemical accidents. In addition, these items can be utilized to perform handling and safety management of chemicals according to whether regulations under the CCA may be implemented.

• Journal of Sensor Science and Technology
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• v.12 no.1
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• pp.34-43
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• 2003

In this study, we implemented the measurement of pH, $pO_2$, $pCO_2$ of the arterial blood on a portable blood gas analysis system. This system is consist of two parts of hardware and software. The hardware part is divided into a fluidic mechanism and an electronic circuit unit. The system program is composed of operating, washing, correcting, and measuring routines. Both of 1-point and 2-point calibration schemes were used to enhance the accuracy of the measurement. In order to evaluate the performance of the developed system, we measured and performed statistical analysis on the characteristics of the sensing electrode response. As a result, coefficient variation was within 1.12, and maximum error was within 1.298%. We confirmed development possibility of portable blood gas analyzer.

• Korean Journal of Veterinary Research
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• v.50 no.1
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• pp.43-48
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• 2010

Animal disease surveillance system, defined as the continuous investigation of a given population to detect the occurrence of disease or infection for control purposes, has been key roles to assess the health status of an animal population and, more recently, in international trade of animal and animal products with regard to risk assessment. Especially, for a system aiming to determine whether or not a disease is present in a population sensitivity of the system should be maintained high enough not to miss an infected animal. Therefore, when planning the implementation of surveillance system a number of factors that affecting surveillance sensitivity should be taken into account. Of these parameters sample size is of important, and different approaches are used to calculate sample size, usually depending on the objective of surveillance systems. The purpose of this study was to evaluate the sensitivity of the current national serological surveillance programs for four selected bovine diseases assuming a specified sampling plan, to examine factors affecting the probability of detection, and to provide sample sizes required for achieving surveillance goal of detecting at least an infection in a given population. Our results showed that, for example, detecting low level of prevalence (0.2% for bovine tuberculosis) requires selection of all animals per typical Korean cattle farm (n = 17), and thus risk-based target surveillance for high risk groups can be an alternative strategy to increase sensitivity while not increasing overall sampling efforts. The minimum sample size required for detecting at least one positive animal was sharply increased as the disease prevalence is low. More importantly, high reliability of prevalence estimation was expected with increased sampling fraction even when zero-infected animal was identified. The effect of sample size is also discussed in terms of the maximum prevalence when zero-infected animals were identified and on the probability of failure to detect an infection. We suggest that for many serological surveillance systems, diagnostic performance of the testing method, sample size, prevalence, population size, and statistical confidence need to be considered to correctly interpret results of the system.