• Korean Journal of Construction Engineering and Management
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• v.18 no.3
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• pp.84-94
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• 2017

Recently, domestic construction companies have increasingly engaged in international PPP projects a result of both uncertainties in the domestic construction market and low competitiveness in international EPC project business. These international PPP projects usually require long-term preparations and substantial sales costs, which make it important for decision-makers to select winning-award potential project in early stage of the projects. However, most previous research has analyzed success factors in terms of project development across all stages. Thus, this study investigated 28 success factors of 4 categories in the early stage of 31 international PPP projects. First, results indicate that unsolicited PPP projects require better implementation capabilities and financial conditions compared to solicited PPP projects. Second, implementation capability is important because it is not easy to improve as the project proceeds. Third, commercial conditions are identified as important even if conditions are not fixed in the early stage of PPP projects. Fourth, non-commercial conditions, strategy, and public interest are not found to be meaningful in the early stage of PPP projects because they can vary as the project proceeds. This study helps to improve selection criteria aimed towards more winning-award potential project in the early stage of international PPP projects.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.19 no.2
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• pp.18-35
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• 2020

Many human, roadway, and vehicle factors affect vehicle-pedestrian crashes. Especially, the roadway factors are easily defined and suitable for suggesting countermeasures. The characteristics of the road network are one of the roadway factors. The road network significantly influences behaviors and conflicts of drivers and pedestrians. A metropolitan city such as Seoul contains various types of road networks, and crash prevention strategy considering characteristics of the road network is required. In this study, we analyze the effects of road networks on vehicle-pedestrian crashes. In the study, high order road ratio, intersection ratio, high-low intersection ratio are considered as road network variables. Using Geographically Weighted Poisson Regression, crash frequencies in Dongs of Seoul are analyzed based on the road network variable as well as socioeconomic variables. As a result, Dongs are grouped by coefficient signs, and each group is suggested about improvement directions considering conflict situations.

• Korean Journal of Construction Engineering and Management
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• v.19 no.4
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• pp.3-11
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• 2018

The Construction Workers Mutual Aid Association is carrying out a number of strategic tasks with the goal of "contributing to improving employment and stabilizing the return of workers to construction workers through employment welfare and retirement deduction services." One of them is the retirement deduction system. The retirement allowance system is a system for the retirement income and livelihood security of construction workers who are not adequately protected by the Labor Standards Act, such as retirement allowances due to the nature of day labor. The Construction Workers Mutual Aid Association has promoted the introduction of electronic manpower management. For the efficient management of the pilot sites and the plans for the future, comprehensive evaluation of the pilot sites as well as the evaluation of the status and operation results of each pilot project site are needed. Therefore, in this study, we will develop performance indicators to evaluate the current state of electronic manpower pilot projects and analyze the actual situation of pilot project sites through actual application, and try to derive future implementation strategies.

• Resources Recycling
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• v.29 no.3
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• pp.43-50
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• 2020

This study reviewed the examples on analyses of the potential impacts to waste management, due to the recent trends of waste trade regulation, and summarized an analysis strategy of the impacts. As a result, a desirable analysis may begin with reasonable estimation of recent waste amounts and flows, and reasonable prediction of the future trends of waste amounts. Then, it is effective to list various key factors and derive future scenarios of the impacts, as well as employ the traditional viewpoints focusing on waste material flow or environmental regulations. The applicable analyses for each scenario can be largely divided into qualitative and quantitative methods. Due to a high uncertainty in the recent international situations with entailing possible innovative economic changes, qualitative methods may be considered in advance, and then quantitative techniques may be utilized to predict gradual changes at relieved uncertainty of the situations. Based on this review so far, proper methodology and procedures for the impact analysis were suggested on recent waste trade conditions in Korea. Given existence of the recent uncertainties such as the health and economic crises, the analysis preferably focused on deriving strategic scenarios with respect to various aspects, and suggested analysis methods applicable to each scenario.

• Korean Journal of Community Nutrition
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• v.21 no.5
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• pp.463-476
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• 2016

Objectives: Environmental, social and personal factors influence eating patterns. This study aimed to investigate the relationship between unhealthy food outlets within a residential area and obesity using nationally representative Korean survey data and data from the Census on Establishments. Methods: Data on the food intakes and socioeconomic variables of a total of 9,978 adults aged ${\geq}19$ years were obtained from the 2013-2014 Korea National Health and Nutrition Examination Survey. Geographic locations of restaurants were obtained from the 2013 Census on Establishments in Korea. Administrative area was categorized into tertiles of count of unhealthy food outlets based on the distribution of number of unhealthy food outlets among all urban (Dong) and rural (Eup or Myun) administrative districts in Korea. Multilevel logistic regressions model were used to assess the association between the number of unhealthy food outlets and obesity. Results: People living in the district with the highest count of unhealthy food outlets had higher intakes of fat (45.8 vs. 44.4 g/day), sodium (4,142.6 vs. 3,949.8 mg/day), and vitamin A (753.7 vs. $631.6 {\mu}gRE/day$) compared to those living in the district with the lowest count of unhealthy food outlets. A higher count of unhealthy food outlets was positively associated with frequent consumption of instant noodles, pizza, hamburgers and sandwiches, sweets and sour pork or pork cutlets, fried chicken, snacks, and cookies. Higher exposure to unhealthy food outlets was associated with increased odds of obesity (1st vs. 3rd tertile; OR 1.689; 95% CI 1.098-2.599). Conclusions: A high count of unhealthy food outlets within a residential area is positively associated with the prevalence of obesity in Korea. The results suggest that food environmental factors affects the health outcomes and interventions aiming to restrict the availability of unhealthy food outlets in local neighborhoods may be a useful obesity prevention strategy.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.6
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• pp.323-328
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• 2016

Pressurized membrane used for side-stream MBR process requires fouling control strategy both for normal and abnormal operation conditions for stable operation of the facilities. In this study, $85m^3/day$ of pilot-scale side-stream MBR process was constructed for the evaluation of fouling mitigation by air bubble injection into the membrane module. In addition, fouling phenomena at abnormal operation conditions of low influent and/or loading rate were also investigated. Injection of air bubble was found to be effective in delaying transmembrane pressure (TMP) increase mainly due to scouring effect on the membrane surface, resulting in expanded filtration cycle at a high flux of $40L/m^2{\cdot}h$ (LMH). At abnormal operation condition, injection of PACl (53 mg/L as Al) into the bioreactor showed 19% reduction of TMP increase. However, inhibition of nitrifying bacteria by continuous PACl injection was observed from batch experiments. In contrast, injection of powdered activated carbon (PAC, 0.6 g/L) was able to maintain the initial TMP of $0.2kg/cm^2$ for 5 days at the abnormal conditions. It may have been caused from the adsorption of extracellular polymeric substances (EPS), which was known to be excessively released during growth inhibition condition and act as the major foulants in MBR operations.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.486-492
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• 2013

Recently, a new disease showing symptoms such as epidermal exfoliation and muscular necrosis occurred in cultured Korean catfish. Although the mortality of fishes was low but the economic damages owing to loss of commercial value were severe. The authors isolated the causative agent from diseased fish and observed pathological changes both in naturally and artificially infected fish. The causative bacteria was identified as Aeromonas veronii. Subsequently we observed the daily death and pathological symptoms of artificially infected fish with Aeromonas veronii. Symptoms of artificially infected fish were similar to those of naturally infected fish and all fish died within 7 days after infection. Histopathological changes on the naturally infected fish revealed severe congestion and necrotic degeneration in the liver, spleen and kidney. Some bacterial aggregates with inflammatory degeneration were observed in the heart, and congestion and fibrosis in the lamina propria of digestive tube were predominant. In artificially infected fish, skin erosion and necrotic degeneration of muscle tissue around injected region were particularly manifested. Degeneration of hepatocytes in liver and hyalic degeneration around ellipsoids in spleen were partially observed. However, there were no predominant signs in digestive tube in artificially infected fish.

• Korean Security Journal
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• no.29
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• pp.223-249
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• 2011

In modern society, citizens' quality of life aspects of safety and crime prevention activities are actively considering the incidence of crime prevention in advance. It also can be quite important elicit the interest of who community members through effective crime prevention strategies. For crime prevention policies and techniques over time as more scientific and advanced methods are made. Today, A typical crime prevention strategies is private security zones and Crime Prevention Through Environmental Design (CPTED) is a corresponding to the new strategy. CPTED is a diversification can be called a crime prevention approach that emphasizes the principle of natural surveillance, access control, territoriality, activity support, maintenance and management. The defensible space of the space area related to crime prevention setting the activities of private security and CPTED determine. Also, the reality of crime prevention and protection should be considered space. The emphasis on proactive prevention of crime in modern society for the prevention of crime how to approach differing perspectives and disparate aspects of private security and CPTED. Technical and professional areas that overlap to some extent in a homogeneous aspect. Ultimately, CPTED is a crime prevention through space and environmental approach for crime. In addition, Ultimate goal of convergence, crime prevention, with the same or higher is required to study for the area after looking for the characteristics and limitations of private security and CPTED.

• Journal of Korean Society of Transportation
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• v.31 no.5
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• pp.60-70
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• 2013

This study aims to develop a truck priority on left-turn algorithm that can reduce greenhouse gas emissions by reducing heavy duty truck's stops at signalized intersection. The signal priority is granted for a left-turn phase, because heavy duty trucks can deteriorate left-turn traffic flow due to the low acceleration or deceleration rate and large turn radius. Truck priority allows to provide the stable speed control for heavy duty truck, and reduces emissions at the signal intersection. Also, two signal recovery strategies are compared for various traffic conditions. This study analyzes the effectiveness of truck priority such as greenhouse gas emissions and fuel consumption reduction, and total travel time saving using the PARAMICS and Comprehensive Modal Emissions Model (CMEM). The results show that signal priority for heavy duty trucks has an effect on reducing greenhouse gas emissions and fuel consumptions at non-peak hour. Also, it shows decreasing total travel time due to reducing truck stops.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.871-884
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• 2021

The purpose of this study was to determine ways to increase efficiency in constructing and verifying artificial intelligence learning data on land cover using aerial and satellite images, and in applying the data to AI learning algorithms. To this end, multi-resolution datasets of 0.51 m and 10 m each for 8 categories of land cover were constructed using high-resolution aerial images and satellite images obtained from Sentinel-2 satellites. Furthermore, fine data (a total of 17,000 pieces) and coarse data (a total of 33,000 pieces) were simultaneously constructed to achieve the following two goals: precise detection of land cover changes and the establishment of large-scale learning datasets. To secure the accuracy of the learning data, the verification was performed in three steps, which included data refining, annotation, and sampling. The learning data that wasfinally verified was applied to the semantic segmentation algorithms U-Net and DeeplabV3+, and the results were analyzed. Based on the analysis, the average accuracy for land cover based on aerial imagery was 77.8% for U-Net and 76.3% for Deeplab V3+, while for land cover based on satellite imagery it was 91.4% for U-Net and 85.8% for Deeplab V3+. The artificial intelligence learning datasets on land cover constructed using high-resolution aerial and satellite images in this study can be used as reference data to help classify land cover and identify relevant changes. Therefore, it is expected that this study's findings can be used in the future in various fields of artificial intelligence studying land cover in constructing an artificial intelligence learning dataset on land cover of the whole of Korea.