• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.14-15
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• 2020

The circumstances of overseas construction market is developing into quite complicated and diversified trends. Construction circumstance is escaping from localization to the open competitions, and from developing countries focused to the resources developing countries. Thus, new strategies for order competitiveness improvement based on our know-hows are required to secure the order volumes. This study has analyzed domestic construction companies' order trends in overseas construction market, and proposed strategic plans through analyzing of Order Causes on overseas construction projects to improve the order competitiveness.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.1
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• pp.57-68
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• 2017

Purpose: The purpose of this study was to compare volumetric modulated arc therapy(VMAT) with fixed-field intensity modulated radiation therapy(IMRT) using non-coplanar beam when the shape of target is irregular and the location is adjacent to organ at risk(OAR). Materials and Methods: The subjects of this study were a total of 6 patients who had radiation therapy for whole scalp(2 patients), partial scalp(2 patients), and whole ventricle(2 patients) by True Beam STX(Varian Medical Systems, USA). VMAT plans consisted of coplanar or non-coplanar arcs which can minimize the volume of OAR included in beamlets. All fixed-field IMRT plans consisted of non-coplanar beams using more than 2 angles of Couch. Results: The VMAT and IMRT plans were compared with regard to the maximum dose of both lens, both optic nerves, optic chiasm, and brain stem and the mean dose of both eyeballs and hippocampus. VMAT plans showed higher dose than ncIMRT plans at more than 6 of all OARs in every patient, and the ratio was from 1.1 times to 8.2 times. In case of total scalp and partial scalp, the volume of brain which received more than 20 Gy in the VMAT plans was 2 times larger than the volume in the ncIMRT plans. In case of whole ventricle, there was no significant difference. Target coverage was satisfied in both plans($PTV_{100%}=95%$). The maximum dose in target volume and required monitor unit(MU) of ncIMRT were higher than them of VMAT plans. Conclusion: Even though ncIMRT is less efficient than VMAT with regard to required MU and treatment time, the dose to OARs is much lower than VMAT and PTV Coverage is similar with VMAT. If the shape of target is irregular and location is adjacent to OAR, comparison VMAT plan with ncIMRT plan deserves to be considered.

• The Journal of Korean Society for Radiation Therapy
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• v.34
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• pp.51-60
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• 2022

Objectives: The purpose is to evaluate dosimetric performance and delivery efficiency of VMAT with Halcyon LINAC for double target spine SBRT Materials and Methods: 12 patients with spine oligometastases were retrospectively studied. Single-isocenter spine SBRT plans was established using Halcyon® with Dual Layer MLC and Truebeam® with High Definition MLC. All patients' plans were created in Eclipse TPS through the identical conditions and optimization. C.I, H.I, G.I (Gradient Index), maximal and volumetric doses to spinal cord and low dose area were evaluated for comparison of both plans. Also, total MU and BOT(Beam On Time) were evaluated. Results: Halcyon plans was no Statistical differences in C.I and H.I. However, the average of G.I was 4.64 for Halcyon, which decreased to 5.5% compared to Truebeam (P<0.001). Halcyon plans demonstrated statistically significant reduced G.I. The average of 50% and 25% isodose volume was 487.56 cc (-3.82%, P<0.001), 1859.45 cc (-4.75%, P<0.001) in Halcyon, respectively. Significantly reduced low dose spill were observed in Halcyon plans. In the evaluation of the spinal cord, the average of Dmean and V10 of Halcyon plans in the sample group with an overlap volume of less than 1 cc was 6.802 Gy (-3.504%, P=0.067), 5.766±1.683 cc (-8.199%, P=0.002), respectively. Halcyon plans demonstrated statistically significant reduced D_mean and V10. For delivery efficiency, MU and BOT(maximum dose rate for each machine), on average, increased in Halcyon plans. However, the average of BOT(800MU/min for each machine) was 648.33 sec for Halcyon (-1.74%, P<0.001). Conclusion: Halcyon plan for double-target spine SBRT demonstrated advantages in the low dose area with a steep dose gradient, while having dosimetrically equivalent target dose distribution and spinal cord protective effect. As a result, Halcyon LINAC produced a dosimetrically improved plan for double-target spine SBRT.

• Journal of Korean Institute of Industrial Engineers
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• v.6 no.2
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• pp.37-47
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• 1980

A system of conditional sampling plans composed of three stages is developed. In the first stage, the decision to accept or reject the lot is based on the information obtained from the current lot. When a decision is not made in the first stage, a second stage is introduced and the information from the immediately preceding lot as well as the information from the current lot is used for the decision. When a decision is not made in the first stage, a second stage is introduced and the information from the immediately preceding lot as well as the information from the current lot is used for the decision. When a decision is not made in the second stage either, the decision is deferred until the information from the immediately following lot is obtained. Existing tables for constructing double sampling plans with $_2$=$2n_1$ can be used to find the parameters of these plans. These sampling plans can bring sizable savings in the amount of inspection when the process is relatively stable. The response delay to the change in process quality and the deferred events may be considered as shortcomings of these plans. However, these are not serious in practical applications, and the reduction in sample size may more than offset these shortcomings.

• Journal of Radiation Protection and Research
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• v.31 no.4
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• pp.187-195
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• 2006

The purpose of this study was to investigate the optimal beam arrangements for hepatic tumors, according to the location of the hepatic tumor and its relationship to organs at risk (OARs). The virtual gross tumor volumes were divided into four groups according to the Couinaud's classification. Several plans were made for each virtual target, and these plans were compared for the normal tissue complication probabilities (NTCP). For group I, NTCP improved as the number of the beam ports increased. However, plans with more than 5 ports had little advantage. For group II, plans with the beam directions from the anterior side showed better results. Group III contained many OARs near the target, which placed restrictions on the beam-directions. Multi-directional plans yielded a higher dose to the OARs than a simple two-port plan using right anterior oblique and posterior beam (RAO/PA). For group IV, a simple RAO/PA port plan was adequate for protection of remaining liver. NTCP can significantly vary between radiotherapy plans when the location of the tumor and its neighboring OARs are taken into consideration. The results in this study of optimal beam arrangements could be a useful set of guidelines for radiotherapy of hepatic tumors.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.4 s.111
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• pp.108-118
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• 2005

While the recent lift of restrictions in greenbelt areas is expected to generate a number of development plans, there are efforts to create various development plans into spatial plans that consider the natural and ecological conditions of development sites. However, these development plans consider Degree of Green Naturality or Degree of Ecology only when designating areas for conservation within development sites. It is true that they don't fully reflect the value of green areas and wetlands as habitats and natural resources. Therefore, this study built an conservation value assessment model that is applicable to sites where development is planned in Korea by reviewing prior case examples md studies and applied the developed model to a case study area. The site where the conservation value assessment model was applied to is an area around Yongsan-ri and Suha-ri, Doam-myon, Pyeongchang-gun, Gangwon province where quality natural resources are located in and wend the site. This is a site for the development of Alpensia Resort where a resort including facilities for the Winter Olympics is planned to be introduced. In order to assess the conservation value of the site for Alpensia Resort, a total of eight items including area, distribution of communities, habitation of species with conservation value, functions of habitats, connectivity of habitats, vegetation layers of forests, age of forests, and ratio of non-native plants were studied through literature review and field surveys. The assessment was made by dividing the site into 95 habitats that are perceived by aerial photographs and each habitat unit was assessed on the eight items in a 3-point scale. Each unit habitat assessed in a 3-point scale was segmented into primary, secondary or tertiary areas based on the conservation value. Habitats assessed as primary were designated as priority (absolute) conservation areas and those assessed as secondary and tertiary were set as secondary conservation areas and tertiary conservation areas, respectively. As a result, each area represented 26.9%, 20% and 3% of total site area. Based on this result, habitat management plans were developed to conserve primary conservation areas, improve secondary conservation areas and restore tertiary conservation areas. In addition, a development plan was developed to create habitats in areas where new habitats are requested in order to build an eco-network in the site and a plan to create eco-corridors was proposed. In developing a land use plan for the site, a development plan that considers conservation areas first should be set up based on the outcome of conservation value assessment. This can be linked to the development of an environment-friendly land use plan as well as easing the establishment of a green area and eco-network. This study will facilitate the implementation of the 'conservation before development' principle, which can prevent reckless development, by assessing conservation value in setting up development plans.

• Journal of Korean Home Economics Education Association
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• v.23 no.2
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• pp.37-54
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• 2011

The purpose of this study was to develop home economics(HE) teaching learning process plans by Gagne's instructional events using scaffolding of 'nutrition and meal of adolescents' unit according to the 2007 revised middle school HE curriculum. To achieve this purpose, the teaching learning process plans and worksheets using scaffolding according to Gagne's instructional event were developed for 5 periods, implemented to the 71 middle school students in Busan city, and evaluated by 21 home economics(HE) teachers and 71 middle school students. The content of the teaching learning process plans were composed of the subjects, 'impotance of nutrition and wellness', 'types of function of nutrients, 'Korean dietary reference intakes and characteristics of adolescent nutrition', 'nutrition problems, eating habits, and diet of adolescents', and 'future health and jobs'. HE teachers evaluated that the content of the teaching learning process plans were suitable to the middle school students, teacher's questions were accurate, and the teaching learning process plans were suitable, usable, and easy to implement in middle school HE class. The students who participated in the class were satisfied with the instruction by Gagne's events using scaffolding. They perceived that the contents and process of the instruction were understandable and interesting.

• Journal of Korean Neurosurgical Society
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• v.61 no.6
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• pp.753-760
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• 2018

Objective : We investigated the effect of optimization in dose-limiting shell method on the dosimetric quality of CyberKnife (CK) plans in treating brain metastases (BMs). Methods : We selected 19 BMs previously treated using CK between 2014 and 2015. The original CK plans ($CK_{original}$) had been produced using 1 to 3 dose-limiting shells : one at the prescription isodose level (PIDL) for dose conformity and the others at low-isodose levels (10-30% of prescription dose) for dose spillage. In each case, a modified CK plan ($CK_{modified}$) was generated using 5 dose-limiting shells : one at the PIDL, another at intermediate isodose level (50% of prescription dose) for steeper dose fall-off, and the others at low-isodose levels, with an optimized shell-dilation size based on our experience. A Gamma Knife (GK) plan was also produced using the original contour set. Thus, three data sets of dosimetric parameters were generated and compared. Results : There were no differences in the conformity indices among the $CK_{original}$, $CK_{modified}$, and GK plans (mean 1.22, 1.18, and 1.24, respectively; p=0.079) and tumor coverage (mean 99.5%, 99.5%, and 99.4%, respectively; p=0.177), whereas the $CK_{modified}$ plans produced significantly smaller normal tissue volumes receiving 50% of prescription dose than those produced by the $CK_{original}$ plans (p<0.001), with no statistical differences in those volumes compared with GK plans (p=0.345). Conclusion : These results indicate that significantly steeper dose fall-off is able to be achieved in the CK system by optimizing the shell function while maintaining high conformity of dose to tumor.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.252-260
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• 2022

The government is emphasizing for a National Food Plan with the aim of establishing a system that can supply healthy and high-quality food to the people. Since consumers' interest and participation are important in vitalizing local food plans, comparative studies on consumer perceptions of food plans are needed. Accordingly, the purpose of the study is to enhance consumers' awareness and understanding of food plans, and to investigate and analyze their perceptions of agriculture and rural areas, and agricultural food consumption behavior according to the level of consumer awareness. As a result of the analysis, consumers were classified into three groups based on the food plan-related awareness score. In terms of marital status unmarried people had a high proportion in the lower group, and married people had a high proportion in the upper group. The higher the perception of food plans, the higher the perception of the importance of eco-friendly or animal welfare foods and the importance of brands when purchasing agricultural and livestock products. The higher the awareness of food plans, the higher the interest of all aspects of food plans. In this study, it can be seen that there were differences in demographic characteristics according to the food plan recognition level groups, in awareness of food plan-related agriculture, and agricultural food product consumption behavior.

• Proceedings of the IEEK Conference
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• 2004.06b
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• pp.481-484
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• 2004

To make production and equipment investment plans in semiconductor Line, implementation of many variables is needed. But these factors could bring many changes and the result is hard to predict. Because prediction is hard, it is hard to make a standard. So this project established Semiconductor production plans using LP Algorithm to satisfy all the conditions from the factors and came up with thesis on reasonable and standardized process.