• Title/Summary/Keyword: build-up effect

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Contamination of the 6MV Linear Accelerator Photon Beam by Electrons (6MV 전자 선형 가속기 광자선의 전자오염)

  • Yoo, Meong-Jin;Kim, Dong-Won;Chung, Woon-Hyuk
    • Journal of Radiation Protection and Research
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    • v.13 no.1
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    • pp.21-30
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    • 1988
  • The 6 MV photon beam of a linear accelerator (Mevatron 67) was studied for electron contamination. The surface dose, attributable almost entirely to contamination electrons, has a linear dependence on field width for square fields and an inverse square dependence on distance from the bottom of the fixed head assembly. Build-up and surface dose measurements were taken with and without an acrylic blocking tray in place. Further measurements were made with a copper filter designed to reduce secondary electrons emitted by photon interactions with the acrylic tray. The results are discussed in relation to skin sparing effect for radiation therapy patients. To achieve the maximum skin sparing effect, the selection of the optimum SSD and TSD is needed.

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Flip Chip Assembly on PCB Substrates with Coined Solder Bumps (코인된 솔더 범프를 형성시킨 PCB 기판을 이용한 플립 칩 접속)

  • 나재웅;백경욱
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2002.11a
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    • pp.21-26
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    • 2002
  • Solder flip chip bumping and subsequent coining processes on PCB were investigated to solve the warpage problem of organic substrates for high pin count flip chip assembly by providing good co-planarity. Coining of solder bumps on PCB has been successfully demonstrated using a modified tension/compression tester with height, coining rate and coining temperature variables. It was observed that applied loads as a function of coined height showed three stages as coining deformation : (1) elastic deformation at early stage, (2) linear increase of applied load, and (3) rapid increase of applied load. In order to reduce applied loads for coining solder bumps on PCB, effects of coining process parameters were investigated. Coining loads for solder bump deformation strongly depended on coining rates and coining temperatures. As coining rates decreased and process temperature increased, coining loads decreased. Among the effect of two factors on coining loads, it was found that process temperature had more significant effect to reduce applied coining loads during the coining process. Lower coining loads were needed to prevent substrate damages such as micro-via failure and build-up dielectric layer thickness change during applying loads. For flip chip assembly, 97Pb/Sn flip chip bumped devices were successfully assembled on organic substrates with 37Pb/Sn coined flip chip bumps.

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An Analytical Model for Predicting Heat Transport with a Sharp Depth Change in Cross-Flow Direction (흐름에 수직한 방향으로 급격한 수심 변화가 존재하는 해역에서의 열오염 이동 예측 해석해 모형)

  • Lee, Ho-Jin;Kim, Young-Ho
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.1
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    • pp.62-72
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    • 2008
  • In this study, an analytical model has been developed to predict the build-up of heat field due to a point heat source in the presence of sharp cross-flow depth change. The model has been applied to investigate the effect of the depth change and flow pattern on the heat field. Model results show that, when there is a sharp depth change in cross-flow direction, the heat transport across the boundary of the depth change is enhanced or diminished according to the increasing or decreasing of the horizontal diffusion flux. Including residual components as well as tidal currents give rise to reduce the effect of the horizontal diffusion on the heat transport because of increasing the advection of heat.

Improvement of Postural Balance and Trunk Muscle Strength: Effect of Free Exercise, Elastic Band Exercise and Balance Exercise (맨손 운동, 탄력밴드 운동과 균형 운동이 고령자의 자세균형 기능 및 체간 근력 증진에 미치는 효과)

  • Seo, Shin Bae;Park, Gyu Jung;Kim, Dong Hyun
    • Journal of the Korean Society for Precision Engineering
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    • v.33 no.12
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    • pp.1031-1037
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    • 2016
  • This study was to verify the effect of complex training programs on the postural balance and trunk muscle strength of the elderly. We recruited 40 elderly participants aged 60 to 75 years. Subjects were evaluated before, and 12 weeks after. The participants underwent complex training programs, including free exercise, elastic band and unstable plate. Exercise were performed as follows: 10 repeats in 50 minutes (0 to 4 weeks), 13 repeats in 50 minutes (5 to 8 weeks), and 15 repeats in 50 minutes (9 to 12 weeks). The training group underwent complex training, including warm up, thrice a week for twelve weeks. The control group did not perform any complex training. Results indicate that the postural balance and trunk muscle strength in the training group significantly increased. Data generated from this study could be applied to develop a complex training program to efficiently build whole body muscle strength.

Effect of ChungHuyl-Plus on inflammatory factors in Human Umbilical Vein Endothelial Cells (HUVECs) (청혈플러스가 혈관내피세포에서 염증 지표인자에 미치는 영향)

  • Seo, Dong-hyo;Joo, In-Hwan;Kim, Dong-Hee
    • Journal of Haehwa Medicine
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    • v.27 no.2
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    • pp.11-20
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    • 2018
  • Objectives : Coronary and cerebrovascular disease with high mortality is a major factor in arteriosclerosis. Pro-inflammatory cytokines damage vascular endothelial cells, leading to vascular inflammation. These vascular inflammation can build up cholesterol and thrombus to cause atherosclerosis. Methods : In this study, we researched the effect of ChungHyul-Plus for vascular inflammation in human umbilical vein endothelial cells (HUVECs) stimulated with tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$). Change in mRNA expression of inflammatory cytokines (CCL5, CXCL8, CX3CL1, and MCP-1), cell adhesion molecules (VCAM-1 and ICAM-1), and anti-inflammation modulators (KLF2 and eNOS) were quantified by qRT-PCR. Results : ChungHyul-Plus decreased expression of inflammatory cytokines and cell adhesion molecules and increased anti-inflammation modulators expression in $TNF-{\alpha}$ stimulated HUVECs. Conclusions : These results suggest that ChungHyul-Plus can be used in the treatment and prevention of vascular inflammation and arteriosclerosis.

Innopolis start-up's achievements and challenges over the past 16 years: the comparison before and after the quantitative expansion period (연구소기업 16년의 성과와 과제: 양적 팽창기 전후의 비교를 중심으로)

  • Seongsang Lee
    • Journal of Technology Innovation
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    • v.31 no.2
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    • pp.111-133
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    • 2023
  • Innopolis start-up has become a representative model and path for commercialization of public technology. Along with the quantitative growth of innopolis start-up, the importance of innopolis start-up in national policies and institutional strategies related to public technology commercialization has also increased. However, over the past 16 years, innopolis start-up's establishment and growth have taken place in different ways at different times. This study aims to compare and analyze changes in innopolis start-up over the past 16 years, focusing on comparisons before and after 2014, when the establishment of innopolis start-up began to increase rapidly. Main findings are as follows. First, in the early stage of the quantitative expansion period, policy changes related to innopolis start-up were the main factors for the increase in innopolis start-ups. In addition, the rapid increase in the establishment of innopolis start-up after 2016 was largely influenced by changes in the start-up environment and institutional changes related to innopolis start-up. Second, the time of registration and size of the capital of innopolis start-up had a statistically significant effect on the sales for 3 years after registration. This result shows that with the rapid increase in innopolis start-ups, the need to build a customized support system for innopolis start-ups by size or growth stage has increased.

The effect of transformational leadership recognized by members of the telemarketing organization on organizational performance-centered on the moderating effect of followership (텔레마케팅 조직구성원이 인식한 변혁적 리더십이 조직성과에 미치는 영향-팔로워십의 조절효과를 중심으로)

  • JiHyun Shim
    • Journal of Service Research and Studies
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    • v.12 no.3
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    • pp.45-59
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    • 2022
  • This study attempted to investigate how the transformational leadership perceived by flowers of telemarketing organizations. In particular, this study explored the moderating effect of followership in the relationship between transformational leadership and organizational performance. To verify the research model, 321 surveys collected from 10 domestic call centers were analyzed. Reliability, correlation, factor analysis, and hierarchical regression analysis were performed, and as a result of the analysis, it was found that the transformational leadership in the telemarketing organizations had a positive effect on organizational performance. In addition, it was confirmed that goal consistency, proactive participation, critical thinking, and team spirit, which are the four sub-variables of followership, all have a positive (+) effect on organizational performance, and both goal consistency and proactive participation moderate the relationship between transformational leadership and organizational performance. Considering the special working environment of telemarketing organizations, the results of this study suggest the need for a corporate educational role to increase transformational leadership and followership and the need to build environments by setting up an atmosphere for members to exercise follow-up, and opening up communication structures for members to follow.

Build up management mind of the construction expert engineer (건설전문기술자의 경영마인드 정립에 관한 연구)

  • Chun, Jin-Ku;Kim, Byeong-Soo
    • Korean Journal of Construction Engineering and Management
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    • v.7 no.3 s.31
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    • pp.45-55
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    • 2006
  • This study aims need set of mind to construction manager built a theory logic conceive decision making system and principles designed to create the administrative procedures that a company needs to integrate management and environmental concerns into its daily business practices. Integrate considerations of risk reduction and wise resource management into daily business decision making environmental that includes performance and cost. Seek to make better Dynamic time solutions that promote competitiveness set of management mind provide business with tools and methodologies management participation, psychology, philosophy effects of resource flows. A last of understand use of the decision making element principal as a guideline for evaluating and ranking approaches. The result of this study are summarized as follows; (1) setting for approach decision making of manager police, (2) dynamic of time and management mind (3) a primary factor out environment to decision making (4) methodologies of set up system for management mind (5) expectation effect of management mind.

The Effect of Airline Service Encounter Quality on Customer Loyalty (항공사 서비스 접점품질이 고객 애호도에 미치는 영향에 관한 연구)

  • Hwang, Yoon Yong;Choi, Soow-A;Na, Kwang-Jin;Kim, Hye-Jin
    • Journal of Korea Society of Industrial Information Systems
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    • v.19 no.4
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    • pp.73-85
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    • 2014
  • The service quality customers perceived has positive relationships with trust, image, and satisfaction toward airline companies. Providing personal and non-personal services could be factors that build up not only overall impressions but positive and negative emotions and could be connected to customer behavioral intention. Thus, this research divided service encounter quality into personal and non-personal encounter quality and investigated effects of two types of service encounter quality on airline image, perceived value and customer loyalty. The result shows that personal service encounter quality has a positive effect on airline image and a negative effect on perceived value. Non-personal service encounter quality has an influence on airline image and a negative influence on perceived value. Personal service encounter quality does not have a significant effect on customer loyalty but non-personal service encounter quality has an effect on customer loyalty. Airline image does not affect perceived vlaue significantly however, do affect customer loyalty. Finally, perceived value does not have a significant effect on customer loyalty.

A Study on the Strategy Highvalue-added in Italian Textile Industry - Focusing on Textile Design- (이태리 섬유산업(纖維産業)의 고부가가치화(高附加價値化) 전략(戰略)에 관한 고찰(考察) - TEXTILE DESIGN을 중심(中心)으로 -)

  • Lee, Eun-Oak
    • Journal of Fashion Business
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    • v.1 no.2
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    • pp.65-73
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    • 1997
  • Over the past, the Korean Textile Industry has been able to establish as one of the most competent textile producer of the world. Today, however, with rapidly changing market requirements, the Korean Textile Industry is requested to improve systems for highvalue textile's market. In this regard, the purpose of this study is to propose suggestions for the strategy recommendations in the Korean Textile Design, researching on the highvalue-added Como Textile Design in Italy. As we analyzed them, the bases of their global success are as follows. 1) Participating in the making of the Global Trend in textile design market, Italian design companies lead to move international market influentially. 2) Dividing target depending on the country's textile market, Italian design companies build up their global marketing capability to increase design sale's effect. 3) Organizing and Participating in the international textile design show and fair, Italian companies attempt to set up Italian image creation as the global advertising. 4) Ensuring an adequate supply of human resource, Industry, Labor Unions, Government and Academy have a cooperative relationship to assist each other. In the basis of the above mentioned, we can suggest the strategies to accelate improvement and development in the Korean Textile and Textile Design Industry. 1) It needes to establish a monitoring system for current information in the International Textile Design Industry. 2) It needs to start building up Korean textile companies global marketing capability to produce adaptable design in market's request. 3) It needs to study and to find our traditional motifs continuosly for creating modern design following the recent Design Trend. Finally, It needs to have a close relationship between industry and education to establish human resource for the Korean Textile Industry's future success in the global market.

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