• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.1
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• pp.22-31
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• 2001

The purpose of this study is to compare calculated pollutant loadings using pollutant load unit factors and vector type coverage, and expected mean concentration(EMC) and raster type of digital elevation model(DEM). This study is also focusing on comparison of the advantages and the disadvantages of the two methods, and seeking for a method of calculation of pollutant loadings using DEM. Estimation of pollutant inputs using pollutant load unit factors has limitations in identifying seasonal variations of pollutant loadings. Seasonal changes of runoffs should be considered in the calculation of pollutant loadings from catchments into reservoirs. Evaluation of pollutant inputs using runoff-coefficient and EMC can overcome these drawbacks. Proper EMC and runoff-coefficient values for the Koeup stream catchments of the Koheung estuarine lake were drawn from review of related papers. Arc/Info was employed to establish database of spatial and attribute data of point and non-point pollutant sources and characteristics of the catchments. ArcView was used to calculate point and non-point pollutant loadings. Pollutant loads estimated with either unit factors-coverages, i.e., pollutant load unit factors and vector coverages f point sources and land use, or EMC and digital elevation mode(DEM) were compared with stream monitoring loads. We have found that some differences were shown between monitoring results and estimated loads by Unit Factors-Coverage and EMC-DEM. Monthly variations of pollutant loads evaluated with EMC-DEM were similar to those with monitoring result. The method using EMC-DEM can calculate accumulated flows and pollutant loads and can be utilized to identify stream networks. A future research on correcting the difference between vector type stream using flow direction grid and digitalizing vector type should be conducted in order to obtain more exact calculation of pollutant loadings.

• Nuclear Engineering and Technology
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• v.37 no.4
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• pp.363-374
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• 2005

A heterogeneous thorium-based Kyung Hee Thorium Fuel (KTF) assembly design was assessed for application in the APR-1400 to study the feasibility of using thorium fuel in a conventional pressurized water reactor (PWR). Thermal hydraulic safety was examined for the thorium-based APR-1400 core, focusing on the Departure from Nucleate Boiling Ratio (DNBR) and Large Break Loss of Coolant Accident (LBLOCA) analysis. To satisfy the minimum DNBR (MDNBR) safety limit condition, MDNBR>1.3, a new grid design was adopted, that enabled grids in the seed and blanket assemblies to have different loss coefficients to the coolant flow. The fuel radius of the blanket was enlarged to increase the mass flow rate in the seed channel. Under transient conditions, the MDNBR values for the Beginning of Cycle (BOC), Middle of Cycle (MOC), and End of Cycle (EOC) were 1.367, 1.465, and 1.554, respectively, despite the high power tilt across the seed and blanket. Anticipated transient for the DNBR analysis were simulated at conditions of $112\%$ over-power, $95\%$ flow rate, and $2^{\circ}C$ higher inlet temperature. The maximum peak cladding temperature (PCT) was 1,173K for the severe accident condition of the LBLOCA, while the limit condition was 1,477K. The proliferation resistance potential of the thorium-based core was found to be much higher than that of the conventional $UO_2$ fuel core, $25\%$ larger in Bare Critical Mass (BCM), $60\%$ larger in Spontaneous Neutron Source (SNS), and $155\%$ larger in Thermal Generation (TG) rate; however, the radio-toxicity of the spent fuel was higher than that of $UO_2$ fuel, making it more environmentally unfriendly due to its high burnup rate.

• Journal of the Korean Society of Radiology
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• v.12 no.7
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• pp.919-927
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• 2018

The purpose of this study was to present simulation training model for general X-ray examinations and to analyze the errors that occur during the simulation training. From 2012 to 2018, a total of 183 students (77 men and 106 women) participated. The simulated X-ray system used computed radiography (CR) system. The contents of simulation training were patient's care, X-ray examinations accuracy, images stability, etc. As a result, it were found that the patient's position setting error, the accuracy error of the X-ray beam central ray, the image receptor's size and setting error, the error of the grid use, the marking error, and the error of X-ray exposure technical factors. It is expected that improved practical general X-ray examinations training of radiographer will be needed, focusing on these errors, so that we could contribute to the health care of the people by providing precise examinations and high quality medical service.

• Journal of Home Health Care Nursing
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• v.27 no.3
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• pp.306-320
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• 2020

Purpose: This study aimed to explore the subjective perception structures and types of empathy among nurses caring for patients with behavioral and psychological symptoms of dementia (BPSD) using Q-methodology. Methods: Thirty-eight Q-samples (statements) were derived from in-depth interviews with 10 nurses working in long-term care hospitals and nursing homes. The Q-sorting was conducted in rank order (the responses obtained by each of the 30 nurses working at 3 long-term care hospitals and 4 nursing homes) into a normal distribution grid (from -4 to +4). The types of empathy among participants were analyzed using the PC-QUANL program. Results: Five types of empathy accounting for 48.5% of the total variance were categorized as follows: (1) taking the patients' personality into consideration while helping, (2) interacting closely and emotionally, (3) supporting the patient as a companion, (4) performing the duty in a defensive manner, and (5) resolving patients' problems by focusing on their needs. Conclusion: This study shows that there are various types of empathy in nurses caring for patients with BPSD. Therefore, it is necessary to develop strategies and educative programs to enhance empathy competency and deal with burnout based on the type of empathy.

• Korean Journal of Remote Sensing
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• v.36 no.6_2
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• pp.1567-1577
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• 2020

Urban land cover classification is role in urban planning and management. So, it's important to improve classification accuracy on urban location. In this paper, machine learning model, Support Vector Machine (SVM) and Artificial Neural Network (ANN) are proposed for urban land cover classification based on high resolution satellite imagery (KOMPSAT-3A). Satellite image was trained based on 25 m rectangle grid to create training data, and training models used for classifying test area. During the validation process, we presented confusion matrix for each result with 250 Ground Truth Points (GTP). Of the four SVM kernels and the two activation functions ANN, the SVM Polynomial kernel model had the highest accuracy of 86%. In the process of comparing the SVM and ANN using GTP, the SVM model was more effective than the ANN model for KOMPSAT-3A classification. Among the four classes (building, road, vegetation, and bare-soil), building class showed the lowest classification accuracy due to the shadow caused by the high rise building.

• 한국정책학회보
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• v.23 no.4
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• pp.179-209
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• 2014

Transition studies have been gaining attention among innovation researchers from the early 1990's mainly influenced by emerging global agendas on sustainability. In this paper, we review research issues and trends focusing on four prominent transition theories - Technological innovation systems, Multi-level perspective, Transition management and Strategic niche management. After reviewing main characteristics, research trends and debates of each theory from established literatures, we conduct comparative analysis of these theories and suggest integrated framework that can be considered when modeling transition policy. This integrated framework is applied to the case study on smart-grid policy of Korea.

• Journal of Korea Society of Industrial Information Systems
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• v.29 no.3
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• pp.41-49
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• 2024

In this paper, we validate simulation results for the design optimization of a Superconducting Fault Current Limiter (SFCL) intended for use in Medium Voltage Direct Current systems (MVDC). With the increasing integration of renewable energy and grid connections, researchers are focusing on medium-voltage systems for balancing energy in new and renewable energy networks, rather than traditional transmission or distribution networks. Specifically, for DC distribution networks dealing with fault currents that must be rapidly blocked, current-limiting systems like superconducting current limiters offer distinct advantages over the operation of DC circuit breakers. The development of such superconducting current limiters requires finite element analysis (FEM) and an extensive design process before prototype production and evaluation. To expedite this design process, the design outcomes are assimilated using a Reduced Order Model (ROM). This approach enables the verification of results akin to finite element analysis, facilitating the optimization of design simulations for production and mass production within existing engineering frameworks.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.2
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• pp.83-95
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• 2016

Strategies for parks and open spaces in the 21st century have moved from focusing on specific elements, such as quantitative growth and ecological and recreational aspects, to green infrastructure, which refers to a multi-functional network of open and green spaces offering a range of benefits. In the case of London, green infrastructure is realised as an integral part of urban infrastructure, involving physical and social infrastructure as well as practical spatial planning at the local level within statutory urban planning as part of a continuously developing green infrastructure framework with a theoretical basis. Taking this perspective, the present study looks at alterations to and developments in green infrastructure policies in the London Plan, the green grid framework as detailed in the city's strategic implementation of green infrastructure. Various trends and characteristics of the policies adopted in the London Plan and some implications are deduced, with three main results being identified. The first is a clear division of roles among the national government, Greater London Authority and borough councils, with local plans established under the guidance of the National Planning Policy Framework (NPPF) and the London Plan. Green infrastructure policies in the London Plan have been applied at a high rate in the boroughs' local plans, which leads to another, linked point. Secondly, green infrastructure policies and the green grid as an implementation framework have been consistently extended and developed through consolidating the London Plan, despite the change of government. Finally, in order to achieve the London Plan, the Mayor of London implemented policies by partnership and supporting programmes for London boroughs. Recently, the Seoul Metropolitan Authority introduced a parks and green spaces development policy, but the London case remains a good example; this is because green infrastructure policies in London were not a manifesto pledge but rather have been continuously and consistently advanced regardless of party politics and thus realised as long-term planning.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.5
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• pp.583-590
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• 2015

Submarine cable installation is essentials for grid connection between existing power grid and newly produced electricity which will be from offshore wind farm in Southwest sea area of Korea. Especially, submarine cable route and protection method is designed in order to ensure the economical efficiency, workability and stability of submarine cable installation. On this paper, we will give the basic information about the submarine cable route and protection method of offshore wind farm which will be built in Southwest sea area of Korea. For this, we have a numerical simulation at high and low tide based on the third-generation wave model SWAN(Simulating WAves Nearshore) using the long term wave data from Korea Institute of Ocean Science and Technology(KIOST). The results of the study, year mean Hs is 1.03m, Tz is 4.47s and dominant wave direction is NW and SSW When the incident wave direction is NW(Hs: 7.0 m, Tp: 11.76s), the distribution of shallow water design wave height Hs was calculated about 4.0~5.0m at high tide and 2.0~3.0m at low tide. When the incident wave direction is SSW(Hs: 5.84 m, Tp: 11.15s), the distribution of shallow water design wave height Hs was calculated about 3.5~4.5m at high tide and 1.5~2.5m at low tide. The wave direction on a dominant influence in the section of longitude UTM 249749~251349(about 1.6 km) and UTM 251549~267749(about 16.2 km) in the submarine cable route are each NW and SSW. Prominently, wave focusing phenomenon appears between Wi-do and Hawangdeung-do, in this sea area is showing a relatively high wave hight than the surrounding sea areas.

• Environmental and Resource Economics Review
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• v.16 no.1
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• pp.99-127
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• 2007

When the margin between available capacity and demand is thin in a liberalized electricity market, prices rise steeply and system reliability is threatened. The principal response to these circumstances is often an assumption that price spikes and electricity shortages are the result of a failure to build sufficient new supplying facilities. It is, of course, often the case that additional investments in generation and network facilities would improve reliability, and such investments are often needed. But focusing on additional generation and transmission facilities for restoring balance to the grid overlooks the essential fact that reliability is a function of the relationship between supply and demand, imposing unnecessary costs on electric system. When the relationship is out of balance, the search for solutions must consider not only investments supply-side resources but also cost-effective demand-side resources such as accelerated load management, efficiency measures, and price-responsive load programs. Integrating demand resources into electricity markets can add enormous value to the electric system, widening the capacity margin, lowering costs and enhancing system reliability at the same time. This paper studies several challenges now facing electricity markets: demand-side management-especially, economic effects of demand response, potential reliability problems, market and system operation, CBP market improvements and so on. The paper concludes with a series of policy recommendations in five areas: (i) The Effects of efficient improvement to incorporate demand responses and demand-side resources into modem electricity markets, (ii) Fosteing price based demand response and (iii) improving incentive based demand response, (iv) strengthen demand response analysis and valuation, (v) integrating demand response into resource planning and adopting enabling technologies.