• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.6 s.113
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• pp.98-108
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• 2006

The climate of urban area is an unstable type with considerable seasonal variation in precipitation wind speed, and temperature and it grows worse. Besides, ozone is a serious air pollutant in most of large cities. So worldwide, some of large cities are investing in forestry options to offset their climate problems, but lack of information has hindered comparisons of urban un cost effectiveness to other options. This research intends to study the economic benefits of tree shading of 19 parking lots in UCD campus. The economic benefits of tree shading are air conditioning savings, air quality, stormwater run-off, and other benefits. Especially, this study focuses how much the economic benefit of parking lot shading has been increased from 1995 to 2003 year by aerophoto. Some data on dimensions of parking lots and the number, size, tree species, and location of trees around each parking lot was inventoried. Two aerophotos(1995,2003) were used in order to analyze the increasement of tree canopy in 19 parking lots for 8 years. However, increasing coverage of trees and managing them for healthy growth would not be sufficient for avoiding adverse impacts by future climate change. Additional measures should be followed such as an increase of energy use efficiency and development of substitute energy. For example, coverage of trees help to save cooling energy by blocking solar radiation reaching parking cars and building structures through shading, and creating cool micro-climates through evapotranspiration. They also reduce heating demand by decreasing air infiltration and heat conduction out of the interior of buildings. Proper arrangement of vegetation over the parking lots can reduce cooling and heating costs. So proper planting design around hard space paving including species selection and location can significantly save cooling and heating energy. And a reduction in car and building's heating and cooling costs results in the reduction in energy demand which causes to emissions of air pollutants. Total increased tree canopy from 1995 to 2003 is $8,470.45m^2$ and the economic benefits is US$ 5,282.10. The economic benefit of one tree has been US$ 7.21 for 8 years. And an annually increased benefit is US$ 0.9 per a tree. If this kind of study is applied to studying the economic benefits of tree canopy in parking lots of Korea, it could result in guidelines of tree planting of parking lots. Because the trees selected for planting in parking lots were not suitable for an environment, the guidelines should contain a recommended list of trees. The guidelines should propose the shading percentage of parking lot when we plan a parking lot and contain the maintenance of trees in order to maximize the economic benefits of tree canopy.

• Journal of Korean Society of Transportation
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• v.26 no.6
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• pp.103-112
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• 2008

Implementing hub networks in logistics is generally attractive and effective because of cost savings derived from economies of scale on network transportation, and objective of the hub network design problem is to decide optimal hub locations, and the transportation route of each origin-destination pair. This problem is generally a NP-complete problem not to solve easily, and it is almost impossible to find optimal solutions considering the big-sized network within a reasonable time. This research tried to find optimal logistics strategy in the given big-sized real network and the freight origin-destination data. The objective function, which was proposed by Honor and O'kelly (2001), that rewards economies of scale on network links with increase of transportation volumes, is applied. This thesis proposed the optimal hub network of korea within a reasonable time based on engineering approaches. And it is expected that this thesis can contribute to plan freight policies which can improve to have competitive power in the level of a company or nation by reducing logistic costs.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.2
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• pp.161-169
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• 2011

Two-way slabs reinforced with high-performance steels, which have several practical advantages of a reduction of congestion in heavily reinforced members, savings in the cost of labor and repair, the higher corrosion resistance, and a reduction of construction time, were constructed and tested. The influences of the flexural reinforcement ratio, concentrating the reinforcement in the immediate column region, and using steel fiber-reinforced concrete (SFRC) in the slab on the punching shear resistance and post-cracking stiffness were investigated, and compared with the punching shear test results of the slabs reinforced with conventional steels and GFRP bars. In addition, the strain distribution of flexural reinforcements and crack control were investigated, and the effective width calculating method for the average flexural reinforcement ratio was estimated. The use of high-performance steel reinforcement increased the punching shear strength of slabs, and decreased the amount of flexural reinforcements. The concentrating the top mat of flexural reinforcement increased the post-cracking stiffness, and showed better strain distribution and crack control. In addition, the use of SFRC showed beneficial effects on the punching shear strength and crack control. It was suggest that the effective width should be changed to larger than 2 times the slab thickness from the column faces.

• Journal of Internet Computing and Services
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• v.16 no.1
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• pp.91-100
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• 2015

Recently many companies began to feel the pressures of cost savings due to the global recession, so they have been interested in the Cloud Computing. Cloud Computing is one of using method of IT resources through the network. Users can borrow softwares or hardwares instead of buying them. Many people expect remarkable growth in Cloud Computing industry because of it's effectiveness. But Cloud Computing industry is still at an early stage. Especially, people who in the public sector hesitate to adopt Cloud Computing Services due to security issues and their conservative views. Also, they just have limited understanding, so we need to investigate what they really know and understand. Researches about the Cloud Computing generally focus on technical issues, so we can hardly find researches reference for decision making in considering the services. The study aims to investigate diverse factors for agencies' adoption decisions, such as benefits, costs, and risk in developing the most ideal type of cloud computing service for them, and performs priority analyses by applying ANP (Analytic Network Process). The results identify that features pertaining to the risk properties were considered the most significant factors. According to this research, the usage of private cloud computing services may prove to be appropriate for public environment in Korea. The study will hopefully provide the guideline to many governmental agencies and service providers, and assist the related authorities with cloud computing policy in coming up with the relevant regulations.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.6
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• pp.97-108
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• 2008

The use of fly ash to replace a portion of cement has resulted significant savings in the cost of cement production. Fly ash blended cement concretes require a longer curing time and their early strength is low when compared to ordinary Portland cement(OPC) concrete. By adopting various activation techniques such as physical, thermal and chemical method, hydration of fly ash blended cement concrete was accelerated and thereby improved the corrosion-resistance of concrete. Concrete specimens prepared with 10-40% of activated fly ash replacement were evaluated for their open circuit potential measurements, weight loss measurements, impedance measurements, linear polarization measurements, water absorption test, rapid chloride ion penetration test and scanning electron microscopy (SEM) test and the results were compared with those for OPC concrete without fly ash. All the studies confirmed that up to a critical level of 20-30% replacement; activated fly ash cement improved the corrosion-resistance properties of concrete. It was also confirmed that the chemical activation of fly ash better results than the other methods of activation investigated in this study.

• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.437-447
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• 2020

The purpose of this study is to research the countermeasures and expected effects through the use of drones in the field of disaster prevention as a drone-based smart quarantine performance method. The environmental, market, and technological approaches to the review of the current quarantine performance task and its countermeasures are as follows. First, in terms of the environment, the effectiveness of the quarantine performance business using drone-based control is to broaden the utilization of forest, bird flu, livestock, facility areas, mosquito larvae, pests, and to simplify and provide various effective prevention systems such as AI and cholera. Second, in terms of market, the standardization of livestock and livestock quarantine laws and regulations according to the use of disinfection and quarantine missions using domestic standardized drones through the introduction of new technologies in the quarantine method, shared growth of related industries and discovery of new markets, and animal disease prevention It brings about the effect of annual budget savings. Third, the technical aspects are (1) on-site application of disinfection and prevention using multi-drone, a new form of animal disease prevention, (2) innovation in the drone industry software field, and (3) diversification of the industry with an integrated drone control / control system applicable to various markets. (4) Big data drone moving path 3D spatial information analysis precise drone traffic information ensures high flight safety, (5) Multiple drones can simultaneously auto-operate and fly, enabling low-cost, high-efficiency system deployment, (6) High precision that this was considered due to the increase in drone users by sector due to the necessity of airplane technology. This study was prepared based on literature surveys and expert opinions, and the future research field needs to prove its effectiveness based on empirical data on drone-based services. The expected effect of this study is to contribute to the active use of drones for disaster prevention work and to establish policies related to them.

• Journal of Korea Water Resources Association
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• v.49 no.9
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• pp.799-807
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• 2016

The aim of this study is to determine and propose the by-pass rainwater sewer system in order to reduce the urban floodplain from the locality heavy rain every year during the dry season and the sinkholes in the city as well as the shortage of groundwaters due to extreme hot weather condition and urban heat island phenomenon. Heavy rain occurs more than the years of heavy rainfall probability, comparison between the place where uses the existing pipes and connect the sewer system with by-pass rain permeability and without expanding sewer pipe replacement at intersection of Gangnam station 3.07 ha at Gangnam-gu, Seoul Metropolitan area, it indicates that average of 27 million KRW (44%) maintenance cost savings and maintain existing sewer system without any other countermeasures. For the city flooded reduction, by-pass rainwater permeable rainwater pipe multiplying the probability the number of years during summer season and increase the water flow capacity during spring and fall when a small amount of rain that, it also contribute to the total amount of underground water secured through the by-pass penetration.

• Korean Journal of Construction Engineering and Management
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• v.19 no.1
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• pp.43-53
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• 2018

Modular construction can improve construction quality and accuracy through manufacturing process, and it allow massive production and cost savings by repeatedly producing the same unit. In particular, it is possible to reduce the time because the on-site work and the manufacturing process can be carried out at simultaneously. However, according to the modular construction project survey report, there is no significant difference regarding the average construction period between modular construction and conventional construction. This is due to schedule delay problems that occur during construction phase. Therefore, it is necessary to select alternatives to prevent schedule delay during on-site construction progressing. Especially, in case of large-scale modular construction project, on-site module assembly and manufacturing process are performed concurrently. Hence, identification of alternatives should be done at the co-occurrence by taking both manufacturing and on-site work process in to account. In this research, the management factors of large-scale modular construction project were identified through the IDEF0 modeling, and the quantity management model for manufacturing and assembly is developed. This will reduce the schedule delay problem that occurs in the progression on-site work of a large scale modular construction.

• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.155-162
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• 2009

The recent increase of light rail construction by the private sector in Korea has caused a new issue in forecasting rail demand. Integrated fare systems between several rail operators is convenient and brings cost savings to users, and therefore is also very effective in increasing demand. However, it causes some short-term revenue loss to operators so that the private sector often suggests a non-integrated fare system. The current rail demand forecasting model is based upon an integrated fare system. Thus this model cannot be used to forecast the demand with a non-integrated fare system. Some value of transfer fare should be estimated and applied to forecast the demand in a non-integrated fare system. This study conducted a stated preference (SP) survey on urban railway passengers and estimated the value of transfer fare. The estimated value is 2,609 Won/hr, which is about 52% of in-vehicle time. This shows railway users have a tendency to pay more for transfer fares to save time or distance. This value has some limitations since it is derived from the SP survey. If some non-integrated fare system is applied in the future and a RP survey is conducted and compared with these study results, a more clear value of the transfer fare will be derived.

• Pediatric Infection and Vaccine
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• v.22 no.3
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• pp.136-142
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• 2015

The Korean Society of Pediatric Infectious Diseases (KSPID) has participated in the task force team consisting of government authorities as well as civil medical experts and facilities to block the spread of Middle East Respiratory Syndrome in 2015. KSPID posted the "Middle East Respiratory Syndrome (MERS) Pop-up" in the homepage of The Korean Pediatric Society and The Korean Society of Pediatric Infectious Diseases. KSPID also released the "Guidelines for testing for MERS in children and adolescents" and the "Instructions for the Operation of National Safe Hospital" for children and adolescents in a timely manner. Such actions were aimed to prevent unnecessary anxieties, studies and isolation of pediatric patients with respiratory symptoms and signs caused by other common microbial etiologies as being suspected for MERS patients. This strategy relieved the doctors and parents from unnecessary fear and prevented the loss of unnecessary health care costs, and has proven to be a well-judged guideline and management protocol as evaluated after the final end of MERS outbreak. KSPID and its members should support the presence of pediatric infectious disease (PID) specialists in every medium size hospitals in Korea by developing the need for consultation fees for PID consultation in the hospital based practice and promoting the potential for cost savings related to prevention of health care associated infections and optimal prescription of antimicrobial agents. KSPID and its members need to approach and develop a communication plan to political decision makers to demonstrate and convince them of the importance of a PID specialist service.