• Journal of Korean Society of Water and Wastewater
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• v.34 no.2
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• pp.149-159
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• 2020

Cured-in-place-pipe(CIPP) is the most adopted trenchless application for sewer rehabilitation to extend the life of the existing sewer without compromising both direct construction and indirect social costs especially applied in the congested urban area. This technology is globally and domestically known to be the most suitable for partial and full deteriorated pipe structure rehabilitation in a sewer system. The typical design of CIPP requires a significant thickness of lining to support loading causing sewage flow interruption and increasing material cost. This paper presents development of a high strength glass fiber composite lining material for the CIPP application and structural test results. The test results exhibit that the new glass fiber composite lining material has 12 times of flexural strength, 6.2 times of flexural modulus, and 0.5 Creep Retention Factor. These test results can reduce lining design thickness 35% at minimum. Even though taking into consideration extra materials such as outer and inner films for actual field applications, the structural capacity of the composite material significantly increases and it reduces 20 percent or more line thickness as compared to the conventional CIPP. We expect that the newly developed CIPP lining material lowers material costs and minimizes flow capacity reduction, and fully replaceable to the conventional CIPP lining materials.

• Nutritional Sciences
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• v.4 no.1
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• pp.34-38
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• 2001

The purpose of this study was to compare the energy expenditure of normal-weight and overweight Korean middle-aged women (40-60 yr). Middle-aged oveweight ($BMI\;{\geq}\;25$, n= 20) and normal-weight women were ($BMI\;{\leq}\;23$, n = 20) were recruited in Seoul. Anthropometric measurements, body composition, energy intake, daily activity time, and energy costs of some daily activities were measured. Energy expenditure at rest and while reading the newspaper, washing dishes, mopping the floor, and walking on a treadmill at 1.0, 2.0, 3.5mph were measured by indirect calorimeter and total daily energy expenditure was estimated by summation of energy costs of different activities. The overweight group had significantly higher values of body weight, triceps skinfold thickness, thigh circumference, waist circumference, hip circumference, BMI, WTR, WHR, body surface area, percentage body fat, fat mass, fat free mass (FFM), and muscle mass compared to normal-weight group. The energy intakes of both groups were close to RDA and other nutrient intake status was also satisfactory. There were no significant differences in intakes of energy and nutrients between the two groups. Overweight subjects showed lower energy expenditure per kg body weight for reading the newspaper, washing dishes and mopping the floor, and walking on a treadmill at 2.0 and 3.5 mph, however, energy expenditure per kg FFM did not differ between the two groups. Daily energy expenditure for all activities was significantly higher in the overweight compared to the normal-weight group due to higher body weight. Both overweight and normal-weight groups showed negative energy balance between energy intake and energy expenditure, and there was no significant difference in energy balance between the two roups. Total daily energy expenditure correlated highly with FFM and body surface area. The result of present study does not offer an explanation on the energy imbalance and weight gain of overweight women.

• Korea Journal of Hospital Management
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• v.4 no.2
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• pp.41-59
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• 1999

Objectives: This study was done to compare patient satisfaction and hospital charges of surgery performed in an outpatient basis(ambulatory surgical procedures). Methods : This retrospective study was performed in 20(vitrectomy 11, tonsillectomy 9) randomly selected ambulatory surgical procedures patients and 50(vitrectomy 26, tonsillectomy 24) inpatients who. received the same procedure at a general hospital in Seoul since January 1, 1998 to October 31, 1998. The operative procedures were vitrectomy and tonsilletomy which could be performed on a ambulatory surgical procedures basis or on an inpatient basis. Results: The results of this study shows that the patients thought the expenses and the surgical operative time was an important factor in a ambulatory surgical procedures but there were no differences in the patient satisfaction by the method of surgery. The charges of vitrectomy and tonsilletomy were reduced up to 495,000 won and 380,000 won from l,589,000 won 842,000 won inpatient surgery respectively. Conclusions: This study focused only on the charges of the surgical procedures and did not include the cost of patient helper, the lost salary due to missing days of work to care for a member of the family, transportation costs, and other indirect costs. Therefore, if those fees were included, ambulatory surgical procedures would be more economical. Therefore, by giving incentives at the fee schedule, the government health policies it would reduce the total hospital charges.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.1 s.28
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• pp.79-85
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• 2004

The GIS(Geographic Information System) projects require big initial investment and cost of maintenance. Decision makers would not launch GIS projects unless they are convinced of the benefits of the projects. Therefore the purpose of this paper is to develop an appropriate model for GIS project evaluation. We proposed a GIS project evaluation model and summarize the steps involved in Cost-Benefit Analysis(CBA). The costs of a GIS implementation include hardware and software cost, costs of database development, training expenses, annual maintenance expenses, and other annual expenses. The benefit by using GIS has been assessed into Type I(direct benefits), Type II(indirect benefits), Type III(benefits that result from the sale of information services), Type IV(intangible benefits).

• Korean Journal of Construction Engineering and Management
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• v.19 no.5
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• pp.43-52
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• 2018

Generally, research on construction cost has been done mostly regarding its direct cost, thus model regarding indirect cost lacks attention. This research seeks to introduce a model to predict on-site overhead cost for apartment construction projects, which constitutes a big portion in Korean construction industry. We devised an equation of 9th degree via curve-fitting, using multiple on-site actual expense data, which can be used to calculate per-progress rate, per-day on-site overhead cost. We further show prospective usage of the model by applying it on construction projects sizing about 30 billion won. Regarding the fact that previous studies could not recognize pattern changes of a total on-site overhead cost, this model is worthy of its conveniency and thoroughness, as well as providing reasonal ground for its derivation in predicting on-site overhead cost of apartment construction projects.

• Journal of the Korea Institute of Building Construction
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• v.21 no.5
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• pp.409-420
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• 2021

The safety and health ledger system, which gives the responsibility of safety and health management for construction site workers to the construction project owner, was introduced as part of the overall revision of the Occupational Safety and Health Act. There is a need to explain the system's effectiveness in terms of economic feasibility to solve the execution problem of the system caused by low awareness and implementation rate. In this study, the economic effect of implementing the safety and health ledger system was analyzed using cost-benefit analysis based on the data discussed at the time of the introduction of the system. Results show that creating and managing the design safety and health ledger caused additional costs in implementing the system. As a result of comparing the cost of preparation and the direct and indirect benefits caused by the reduction of industrial accidents, the benefits were evaluated higher than the costs. Thus, it is thought that the safety and health ledger system reduces construction work accidents and generates economic effects.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.16 no.2
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• pp.97-105
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• 2021

Objectives This study is aimed to evaluate cost-effectiveness of treatment of Korean Medicine for whiplash associated disorders (WAD) and to suggest the direction of future research. Methods We searched papers in Pubmed database to use some keywords indicating whiplash injury syndrome, treatment of Korean Medicine and cost-effectiveness. After searching, appropriate papers were selected depending on the exclusion criteria. The selected papers were analyzed in the sections of author, publication year, intervention and control groups, outcome measurement, the list including in the cost, cost-effectiveness, cost-utility and study design. Results Four studies about effect of Korean medicine and 3 studies about economic evaluation were finally included. Acupuncture was effective for balance disorder and neck pain. Economic evaluation studies used analytical decision model or cost-consequence analysis. Cost-effectiveness analysis using visual analog scale and cost-utility analysis using quality adjusted life years were performed. Initiating timing of proper management affected the consequence of treatments. Direct and indirect medical costs including supportive devices, and non-medical costs such as litigation were considered. Conclusions We conclude that studies haven't been conducted so far to evaluate the cost-effectiveness of Korean Medicine in whiplash injury syndrome. Thus, future studies are needed in this section.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2418-2425
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• 2021

Monazite is a phosphate mineral that contains thorium (Th) and rare earth elements. The Th concentration in monazite can be as high as 500 ppm, and it has the potential to be used as fuel in the nuclear power system. Therefore, this study aimed to conduct the techno-economic analysis (TEA) of Th extraction in the form of thorium oxide (ThO₂) from monazite. Th can be extracted from monazite through an alkaline fusion method. The TEA of ThO₂ production studied parameters, including raw materials, equipment costs, total plant direct and indirect costs, and direct fixed capital cost. These parameters were calculated for the production of 0.5, 1, and 10 ton ThO₂ per batch. The TEA study revealed that the highest production cost was ascribed to installed equipment. Furthermore, the highest return on investment (ROI) of 21.92% was achieved for extraction of 1 ton/batch of ThO₂, with a payback time of 4.56 years. With further increase in ThO₂ production to 10 ton/batch, the ROI was decreased to 5.37%. This is mainly due to a significant increase in the total capital investment with increasing ThO₂ production scale. The minimum unit production cost was achieved for 1 ton ThO₂/batch equal to 335.79 $/Kg ThO₂.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.6
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• pp.131-142
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• 2007

The road user cost in indirect costs as well as direct costs such as the inspection/ diagnosis cost and the repair/reinforcement cost should be considered as one of the important items in the life-cycle cost-effective design and maintenance of the bridges. To estimate the road user cost, this paper formulates the road user cost as a sum of the user delay cost and the vehicle operating cost considering the detour effect. A numerical traffic simulation and a regression analysis are performed to develop a regression model due to a time delay. The proposed regression model is applied to the generation of the maintenance strategy based on the life-cycle cost and performance, and its effectiveness and applicability is investigated. The road user cost has a great influence on establishing the maintenance strategy, and the proposed regression model could be successfully utilized to estimate the road user cost of a bridge.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.1035-1040
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• 2024

South Korea has seen an increased demand for road maintenance, since they experienced a rapid industrialization in 1960-70s. Between 2019 and the end of 2022, the total national expenditure on road maintenance steadily rose from KRW 3.4 trillion to KRW 4.5 trillion. Roads, responsible for about 80% of the nation's transportation, significantly affect ride quality, safety and maintenance costs. Among the different perspectives, this study focuses on the prevalence of potholes. Over 24,000 pothole instances are reported on highways in the past five years, which raises concerns due to various direct and indirect effects on road maintenance and safety issues. Various methods, including vision-based, vibration-based, and 3D reconstruction-based techniques, have been proposed for pothole detection and inspection. Vision-based methods effectively count and measure pothole shapes but which are sensitive to lighting conditions. Vibration-based methods offer cost-effectiveness, although it may not provide precise pothole shape information. 3D reconstruction-based methods deliver accurate shape measurements, while it comes with higher costs. To establish an effective road maintenance system, prioritization criteria for potholes is required to be established and applied. These criteria may vary across countries or regions. For example, in the United States, potholes are classified based on depth into Low (<25mm deep), Moderate (25 to 50mm deep), and High (>50mm deep). In conclusion, this research addresses this research challenge of road damage and potholes in South Korea by exploring various pothole classification standards and utilizing advanced technology to develop an efficient road maintenance system. The outcome would benefit improved road infrastructure management and enhanced safety.