• Journal of Korean Society of Disaster and Security
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• v.15 no.3
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• pp.79-88
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• 2022

Cable-supported bridges, as important large infrastructures, require a long-term and systematic maintenance strategy. In particular, various methods have been proposed to secure safety for the bridges, such as installing various types of sensor on members in the bridges, and setting management thresholds. It is evidently necessary to propose a strategic plan to efficiently manage increasing number of cable-supported bridges and data collected from a number of sensors. This study aims to develop an analysis tool that can automatically remove abnormal signals and calculate statistical results for the purpose of efficiently analyzing a wide range of data collected from a long span bridge measurement system. To develop the tool, basic information such as the types and quantity of sensors installed in long span bridges and signal characteristics of the collected data were analyzed. Thereafter, the Humpel filtering method was used to determine the presence or absence of an abnormality in the signal and then filtered. The statistical results with filtered data were shown. Finally, one cable-stayed bridge and one suspension bridge currently in use were chosen as the target bridges to verify the performance of the developed tool. Signal processing and statistical analysis with the tool were performed. The results are similar to the results reported in the existing work.

• Journal of the Korea Institute of Building Construction
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• v.22 no.4
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• pp.391-402
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• 2022

With the number of social overhead capital(SOC) projects that introduce private capital on the rise, overseas construction global companies today need to establish and advance their overseas order strategies. In this context, the purpose of this study is to develop the public private partnership(PPP) capacity evaluation model for developing countries and use it for domestic overseas construction companies to establish strategies for overseas expansion. The PPP competency evaluation model analyzes the importance of PPP competency evaluation items and infrastructure environment competency evaluation items through a review of previous studies and an interview survey with overseas construction experts. Through the above analysis results and expert surveys, problems that may occur when overseas construction companies enter the PPP market were derived, and improvement measures were proposed. Countries with a high probability of overseas construction companies entering the PPP market were determined to be those that have a mature PPP system, low risk in construction, and a good entry environment with a high infrastructure market size and growth rate. In addition, a lack of PPP investment experience, the absence of information on the infrastructure environment, and a shortage of PPP experts were identified as problems when entering the overseas construction PPP market. As an improvement measure, it was suggested to enter in cooperation with domestic and foreign companies. In addition, a plan was proposed to develop a curriculum to secure experts in areas such as PPP finance and contracts and to provide PPP information for each country. These findings are expected to contribute to overseas construction companies proposing strategies for entering the overseas construction market and using them for overseas expansion strategies and policy establishment.

• Korean Journal of Plant Resources
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• v.35 no.4
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• pp.471-501
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• 2022

This study was carried out on 455 forest wetlands of south Korea for which an inventory was established through value evaluation and grade. Correlation analysis was conducted to find out the correlation between the types and grades of forest wetlands and 23 evaluation factors in four categories: vegetation and landscape, material circulation and hydraulics·hydrology, humanities and social landscape, and disturbance level. Through the improvement of types and grades of forest wetlands, it is possible to secure basic data that can be used in setting up conservation measures by preparing standards necessary for future forest wetland conservation and restoration, and to found a systematic monitoring system. First, between the type of forest wetland and size and accessibility showed a positive correlation, but the remaining items were analyzed to have negative or no correlation. In particular, it was found that there was no negative correlation or no correlation with the grades of forest wetland. Moreover, it was found that there was a very strong negative correlation with the weighted four category items. Thus, it is judged that improvement is necessary because there is an error in the weight or adjust the evaluation criteria of the value evaluation item, add an item that can increase objectivity. Especially, in the case of forest wetlands, the ecosystem service function due to biodiversity is the largest, so evaluation items should be improved in consideration of this. Therefore, it can be divided into five categories: uniqueness and rarity (15%), wildlife habitat (15%), vegetation and landscape (35%), material cycle·hydraulic hydrology (30%), and humanities and social landscape (5%). It will be possible to propose weights that can increase effectiveness.

• Journal of Industrial Convergence
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• v.20 no.11
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• pp.85-93
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• 2022

As of the end of 2019, the total population nationwide was 51,849,861, and over the past five years, the population per household has decreased by 1.52% annually from 2.45 in 2015 to 2.31 in 2019. Looking at the current status of population distribution by age group, Busan metropolitan city had the highest proportion of senior citizens aged 65 or older at 18.2%, and Sejong Special Self-Governing city had the lowest at 9.4%. In particular, as of 2019, the population of the mobility handicapped was 15,219,000 nationwide, showing a ratio of about 29.4% of the total population. Therefore, it is important to secure the right to move according to the mobile facilities so that the mobility handicapped can move safely and conveniently. Against this background, this study places value on transportation welfare facilities centered on the mobility handicapped for safe and convenient movement, and in particular, in proposing measures to cope with the entry of an aging society and the continuous increase of the mobility handicapped, the transportation facilities, The purpose of this study is to analyze the impact of welfare facilities on the mobility handicapped and suggest implications. As a research method, the results of statistical analysis methods were presented through major preceding studies and expert surveys.

• Journal of Korean Society of Disaster and Security
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• v.16 no.1
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• pp.23-35
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• 2023

Recently, the damage caused by natural disasters such as typhoons and localized torrential rains has been increasing rapidly. The Ministry of the Interior and Safety enacted a ｢law on safety management of small sized infrastructures｣ and local governments have to register small sized infrastructures with the National Disaster and Safety Management System (NDMS) until March 31st every year. Recently, each local government has ordered Safety inspections of small sized infrastructures and maintenance plans and six types of facilities, including small streams, small bridges, farm roads, access roads to village, inlet weirs, and drop structures are being surveyed and digitized into a database. Each facility is being evaluated for risk, and for those deemed hazardous, maintenance plans are being developed. However, since the risk assessment method of small sized infrastructures is not clear so that is conducted through visual investigation by field investigators, risk assessment is conducted in a subjective and ambiguous form. Therefore, this study presented a reasonable and quantitative risk assessment method by providing a quantitative evaluation indicator for small stream, which has the highest disaster risk among other small sized infrastructures, so that small sized hazard infrastructures can be selected to secure transparent evidence for improvement plans and action plans.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.4
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• pp.14-34
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• 2023

The purpose of this study was to calculate the appropriate yellow-signal time for intersections, to find out the relationship between the approach speed and intersection width when calculating the time, and to secure safety by minimizing conflicts and dilemma sections in intersections that change according to the signal operation. For this purpose, 6,824 data points from 5 intersections were collected and analyzed. The main results of the study are as follows. First, the approach speed of individual vehicles in different lanes was analyzed, and the width of an intersection was defined by considering the conflict in each direction. Second, we developed a multiple regression model based on the approach speed and conflict points, which compensated for the problems of an existing formula. Third, a standard table is presented for applying the appropriate yellow-signal time according to the approach speed and intersection width based on a development formula. A method is also presented to determine the safety of the length of the dilemma according to the change in the yellow-light time by presenting a calculation table that can cross-analyze the yellow-signal time and a dilemma section using the relationship.

• Journal of Wetlands Research
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• v.25 no.3
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• pp.167-175
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• 2023

Precipitation data is one of the essential input datasets used in various fields such as wetland management, hydrological simulation, and water resource management. In order to efficiently manage water resources using precipitation data, it is essential to secure as much data as possible by minimizing the missing rate of data. In addition, more efficient hydrological simulation is possible if precipitation data for ungauged areas are secured. However, missing precipitation data have been estimated mainly by statistical equations. The purpose of this study is to propose a new method to restore missing precipitation data using machine learning algorithms that can predict new data based on correlations between data. Moreover, compared to existing statistical methods, the applicability of machine learning techniques for restoring missing precipitation data is evaluated. Representative machine learning algorithms, Artificial Neural Network (ANN) and Random Forest (RF), were applied. For the performance of classifying the occurrence of precipitation, the RF algorithm has higher accuracy in classifying the occurrence of precipitation than the ANN algorithm. The F1-score and Accuracy values, which are evaluation indicators of the classification model, were calculated as 0.80 and 0.77, while the ANN was calculated as 0.76 and 0.71. In addition, the performance of estimating precipitation also showed higher accuracy in RF than in ANN algorithm. The RMSE of the RF and ANN algorithms was 2.8 mm/day and 2.9 mm/day, and the values were calculated as 0.68 and 0.73.

• Korean Journal of Forensic Psychology
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• v.12 no.2
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• pp.223-251
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• 2021

Statement analysis is a technique that examines the credibility of a statement by scientifically analyzing problems and psychological characteristics that appear in the content of the statement. The statement analysis report is prepared, submitted, and used for legal judgments when there is a suspicion of sexual abuse for children(under 13 years of age) and persons with disabilities since it is usually difficult to secure physical evidence nor eyewitnesses. However, the criteria for evaluating the quality of a statement analysis report or testimony are not available in Korea. Although forensic experts and professional organizations in North America and Europe are providing recommendations and guidelines for preparing forensic assessment reports, qualitative analysis research studies for forensic reports revealed a number of problems such as missing or poorly described essential information and lack of logical connection between evaluation results and forensic opinions. Therefore, forensic evaluation guidelines and forensic reports submitted to the courts in the United States, as well as the Structured Quality assessment of eXpert testimony (SQX-12) developed in Sweden were examined to suggest the Korean version of quality evaluation criteria for statement analysis report and testimony. This criteria can be used to improve effectiveness of forensic reports within criminal justice system and used as a guideline to assess the quality forensic reports or expert testimony prepared by experts. However, this criteria do not guarantee the reliability of the statement itself.

• The Journal of the Acoustical Society of Korea
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• v.42 no.2
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• pp.133-142
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• 2023

The office environment is changing according to work types, Information Technology (IT) advancements, and the Coronavirus disease (COVID)-19 situation. In order for office space users to perform their tasks comfortably and efficiently, it is necessary to secure individual privacy as well as easy communication among members. In Korea, the demand for improving the acoustic performance of office spaces is also increasing, but the related performance criteria and guidelines have not been established. In this study, standardization of office space acoustic performance measurement and evaluation methods and European countries' acoustic performance criteria were compared and reviewed. It is proposed to comprehensively review international standardization trends and acoustic performance standards in each country and to establish and utilize criteria for evaluating the acoustic performance and satisfaction of office spaces in Korea through our survey. Considering the international standardization direction and compatibility with communication and Public Address (PA) systems, it is appropriate to establish criteria using the speech transmission index or Speech Transmission Index (STI) application index. This criterion will be highly utilizable and compatible. In addition, since the office furniture industry is interested in improving the acoustic performance of office space, it is necessary to establish a labelling system for speech level reduction of office furniture.

• Industry Promotion Research
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• v.8 no.2
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• pp.119-132
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• 2023

The purpose of this paper is to re-establish the concept of Eastern time, which is used in Myeongliology and Kimun-dungap, and to discuss the use of real-time of the sun according to the birth area, the selection of real-jasi between night-jasi and real-jasi, and the exact meaning of birth time. The conventional use of time in Korean society uses Tokyo as standard time and uses a time system in which a new day begins at midnight. Howev er, what is important is not social univ ersality but the time and space of the univ erse where I was born, which is the center of the universe, should be the standard of my fate, so I have to use the longitude of the place where I was born to determine my exact time. Also it is argued that real-jasi should be selected for the selection problem of night-jasi and real-jasi, which has long been a controversial topic in Myeongliology, because the flow of cosmic energy is signaled an hour ahead. To secure the validity of setting such time, a case analysis was conducted using the time adjustment method through the spread of Kimun-dungap. Through in-depth interviews with the analysis subjects, the lives of the past were collected by date and time, and then Kimun-dungap checked whether the timing of each life event was accurate.