• Asian Pacific Journal of Cancer Prevention
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• v.15 no.11
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• pp.4727-4732
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• 2014

Background: Breast cancers are becoming more frequently diagnosed at early stages with improved long term outcomes. Late normal tissue complications induced by radiotherapy must be avoided with new breast radiotherapy techniques being developed. The aim of the study was to compare dosimetric parameters of planning target volume (PTV) and organs at risk between conformal (CRT) and intensity-modulated radiation therapy (IMRT) after breast-conserving surgery. Materials and Methods: A total of 20 patients with early stage left breast cancer received adjuvant radiotherapy after conservative surgery, 10 by 3D-CRT and 10 by IMRT, with a dose of 50 Gy in 25 sessions. Plans were compared according to dose-volume histogram analyses in terms of PTV homogeneity and conformity indices as well as organs at risk dose and volume parameters. Results: The HI and CI of PTV showed no difference between 3D-CRT and IMRT, V95 gave 9.8% coverage for 3D-CRT versus 99% for IMRT, V107 volumes were recorded 11% and 1.3%, respectively. Tangential beam IMRT increased volume of ipsilateral lung V5 average of 90%, ipsilateral V20 lung volume was 13%, 19% with IMRT and 3D-CRT respectively. Patients treated with IMRT, heart volume encompassed by 60% isodose (30 Gy) reduced by average 42% (4% versus 7% with 3D-CRT), mean heart dose by average 35% (495cGy versus 1400 cGy with 3D-CRT). In IMRT minimal heart dose average is 356 cGy versus 90cGy in 3D-CRT. Conclusions: IMRT reduces irradiated volumes of heart and ipsilateral lung in high-dose areas but increases irradiated volumes in low-dose areas in breast cancer patients treated on the left side.

• Journal of electromagnetic engineering and science
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• v.6 no.2
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• pp.103-109
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• 2006

This paper suggests an efficient and comprehensive algorithm of the protection ratio derivation and illustrates some calculated results applicable to the initial planning of frequency coordination in the fixed wireless access networks. The net filter discrimination associated with Tx spectrum mask and overall Rx filter characteristic has been also examined to show the effect of the adjacent channel interference. The calculations for co-channel and adjacent channel protection ratios are performed for the current microwave frequency band of 6.7 GHz including Tx spectrum mask and Rx filter response. According to results, fade margin and co-channel protection ratio reveal 41.4 and 75.2 dB, respectively, for 64-QAM and 60 km at BER $10^{-6}$. It is shown that the net filter discrimination with 40 MHz channel bandwidth provides 28.9 dB at the first adjacent channel, which yields 46.3 dB of adjacent channel protection ratio. In addition, the protection ratio of 38 GHz radio relay system is also reviewed for millimeter wave band applications. The proposed method gives some advantages of an easy and systematic extension for protection ratio calculation and is also applied to frequency coordination in fixed millimeter wave networks.

• Korean Management Science Review
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• v.20 no.2
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• pp.113-133
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• 2003

This study developed the ISM (Electronic Store Success Model) by basing upon the revised D&M IS Success Model and reflecting the characteristics of marketing and e business. The theoretical rationale of this model was as following : 1) Though the revised D&M IS Success Model (2002) must be more logical and complete model than the original D&M IS Success Model (1992), it did not reflect characteristics of marketing and e business. 2) In the marketing studios, Service Quality has been suggested as one of basic strategies for success. 3) In e business studies, Trust has been emerging as a potentially important antecedent of e loyalty. 4) There has been a paradigm shift from satisfaction to loyalty in marketing emphasis. 5) Nowadays, ERP (Enterprise Resource Planning) has been pervaded in many organizations and has supported PCA (Profit Center Accounting) or Channel based Accounting, so it has not been difficult to evaluate financial performance of Electronic Store. The ESM that has six dimensions (System Quality, information Quality. Service Quality, Trust, Loyalty, Financial Performance) and expresses the causal relationship among them was proposed and was compared with BSC (Balanced Scorecard), WebQual, and EWAM (Extended Web Assessment Method). The results showed that the ESM coincides with BSC and contains dimensions of WebQual, and EWAM.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.4
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• pp.105-118
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• 2007

The purpose of this study is not only to compare between 'Opened Landscape' and 'Filtered Landscape' image and preference but also to suggests a guide line of planting design for progressive realization. For this, the image structures of photo-sketch simulation for parallax landscape have been investigated by Semantic Differential scale(S.D. scale) and the Factor analysis. The results could be summarized as follows. The results of S.D. scale values for landscape through parallax were greater than non-parallax landscape. The scenes through parallax were better preferred to direct view. Thus the results of photo-sketch simulation test support the expected hypothesis that the visual environment of complexity and variety is closely correlated with the parallax effect and monotonous or non-parallax environment, and parallax effect on close view more bigger than the distant view. Factors covering the spatial image of parallax landscape were found to be seven and Total values were 60.35 %. The most important factors determining the parallax effect were Factors I 'depth of space' and VI 'expectation of space and interest'. An outstanding view must be handled properly to be preserved or accentuated. In this sense, the parallax spatial beauty with tree could be improved through the visual aspects of plan arrangements and the progressive realization appeared to be one effective design technique for landscape planning and design.

• Economic and Environmental Geology
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• v.51 no.3
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• pp.279-289
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• 2018

With the launch of the new government in 2017, National Planning and Advisory Committee (NPAC) announced the five-year plan for the government administration and the 100 national tasks. The Ministry of Science and ICT (Information & Communication Technology) (MSIT) and other government agencies issued work plans for 2018, including R&D plans. Analyzing the changes in government policy will be a major task of public research and development institutions. This study analyzed the changes of the R&D policy of the new government and the R&D policy direction and strategic plan of the government departments related to the geoscience and mineral resources in 2018. The results of the analysis are as follows: 1) to lead the innovation growth through the 4th industrial revolution, 2) to supply clean energy and to cope with climate change in the environment and energy field, 3) to improve the quality of life through problem solving in the life of the people and disaster prevention. Considering the investment direction of the government, it is necessary to lead the geoscience and mineral resources R&D to solve problems of the society and to grow by the science and technology.

• Journal of the Economic Geographical Society of Korea
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• v.14 no.4
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• pp.671-683
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• 2011

The technical development of transportation and communication increases freedom of location choice. This higher freedom allows to company can pursues bigger profit than before. Company's separated spatial configurations tend to go to most optimal location, so some places showed unexpected agglomeration. This study conducted to prove "dispersed concentration" for specific example, pharmaceutical enterprises, in real business world. As a result, separation of spatial configuration clearly observed as product output goes bigger and R&D's depth goes deeper. And spatial concentration of each function was found. Most headquarters are located in Seoul, R&D centers make agglomeration at some spaces. Plants' location concentrated until 1990s, but, in 2000s, plants expand out of metropolitan area.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.5
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• pp.311-317
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• 2015

The aim of this study is to develop a 3D registration algorithm for positron emission tomography/computed tomography (PET/CT) and magnetic resonance (MR) images acquired from independent PET/CT and MR imaging systems. Combined PET/CT images provide anatomic and functional information, and MR images have high resolution for soft tissue. With the registration technique, the strengths of each modality image can be combined to achieve higher performance in diagnosis and radiotherapy planning. The proposed method consists of two stages: normalized mutual information (NMI)-based global matching and independent component analysis (ICA)-based refinement. In global matching, the field of view of the CT and MR images are adjusted to the same size in the preprocessing step. Then, the target image is geometrically transformed, and the similarities between the two images are measured with NMI. The optimization step updates the transformation parameters to efficiently find the best matched parameter set. In the refinement stage, ICA planes from the windowed image slices are extracted and the similarity between the images is measured to determine the transformation parameters of the control points. B-spline. based freeform deformation is performed for the geometric transformation. The results show good agreement between PET/CT and MR images.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.4
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• pp.289-301
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• 2020

Since sewer rehabilitation program requires long construction period and enormous capital investment, determination of rehabilitation priorities is important with systematic planning considering appropriate evaluation parameters. In this research, we applied PROMETHEE(Preference Ranking Organization METHod for Evaluations) known as very objective and scientific multi-criteria decision-making analysis, using the weights determined by AHP(Analytic Hierarchy Process) for the selected sewer evaluation items to calculate the rehabilitation priorities for each sewer sub-catchment in basin Gusan 1 of Seoul. Preference functions and preference thresholds were estimated for each criterion of ratio of lack of hydraulic capacity of sewers, defect ratio, ratio of sewers with velocity less than its minimum criteria, and density of sewers in the sub-catchment. As a result, it was found that region d had the first priority among four sub-catchments. For each and every sewer located in region d, we could also rank sewers to be rehabilitated urgently.

• Publications of The Korean Astronomical Society
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• v.22 no.4
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• pp.229-236
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• 2007

Many departments in the governmental organization including Ministry of Science & Technology (MOST) allocate some of their budget into research and development in astronomy and space science. We identify the research projects related to astronomy and space science that were funded by the government during fiscal years 2004-2005. Then the distribution of budgets of those projects is analyzed according to several classification schemes and characteristics in order to find out the status and trends of the investment in this field. Five departments had conducted more than 190 projects related to astronomy and space science, which accounted for 7.3% of the government R&D budget in space and aeronautics area. As for most fields of basic science, MOST and Ministry of Education & Human Resources Development invested the most of budget in astronomy related projects. We briefly discuss the implications of this study.

• International Journal of Contents
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• v.13 no.4
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• pp.12-15
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• 2017

Among the possible stereotactic body radiation therapy (SBRT) modalities used to treat patients with metastatic spinal tumors, this study compared Cyberknife, tomotherapy, and volumetric modulated arc radiotherapy (VMAT). We established treatment plans for each of them modality and quantitatively analyzed the dose evaluation factors of the dose-volume histogram (DVH) for all spinal bones, focusing on the tumor and spinal cord, in order to examine the usefulness of VMAT. For the treatment planning dose, the mean dose ($D_{max}$) and $D_{5%}$ showed statistical differences in the target dose, but no difference was shown in the spinal cord dose. For the DVH indices, tomotherapy showed the best performance was the best in terms of uniformity index, while VMAT showed better performance was better than the other two modalities in terms of the conformity index and the dose gradient index. VMAT had a much shorter treatment time than Cyberknife and tomotherapy. These findings suggest that VMAT FFF is the most effective therapy for SBRT of patients with metastatic spinal tumors for whom a high dose of radiation is prescribed.