• Title/Summary/Keyword: point of impact

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Flexural Characteristics of High Performance Fiber Reinforced Cement Composites used in Hybrid Synthetic Fibers (하이브리드 합성섬유를 이용한 고인성 섬유보강 복합체의 휨특성)

  • Han Byung Chan;Jeon Esther;Park Wan-Shin;Lee Young-Seak;Hiroshi Fukuyama;Yun Hyun-Do
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.734-737
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    • 2004
  • The synthetic fibers such as polypropylene(PP) and polyvilyl-alcohol(PVA) fiber are poised as a low cost alternative for reinforcement in structural applications. It has been reported that synthetic fiber in cement composites can control restrained tensile stresses and cracks and increase toughness, resistance to impact, corrosion, fatigue and durability. High performance fiber reinforced cementitious composite(HPFRCCs) shows ultra high ductile behavior in the hardened state, because of the fiber bridging properties. Therefore, a variety of experiments have being performed to access the performance of HPFRCCs recently. The research emphasis is on the flexural behavior of HPFRCCs made in synthetic fibers, and how this affects the composite property, and ultimately its strain-hardening performance. Three-point bending tests on HPFECCs are carried out. As the result of the bending tests, HPFRCCs showed high flexural strength and ductility. HPFRCCs made in PVA or Hybrid fiber were, also, superior to PP of singleness. On the other hand, effect of sand volume fraction on HPFRCCs made in PP was insignificant.

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Analysis of airborne sound insulation performance by the experiment using small size specimen (축소시편 실험을 통한 공기전달음 차단성능 분석)

  • Kim, Hang;Park, Hyeon Ku;Goo, Hee Mo;Kim, Sun-Woo
    • KIEAE Journal
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    • v.14 no.1
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    • pp.83-89
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    • 2014
  • The residents' demand for the comfortable life is promoting development of wall and window which has high sound insulation performance. To develop wall system, various aspects should be considered on the environment, material, construction and structure. Especially focusing on the acoustical view, the economical solution is one of the most critical point. Recently the interest on the partition wall is being increased, because it is useful for the Rahmen type apartment which is considered as an alternative to reduce floor impact sound. This study examines simplified measurement method of airborne sound insulation applied small size specimen, in order to save money to be used for the standard specimen then to promote the development process. The results showed that the simplified method could be effective for the wall system the sound insulation performance upto Rw 50 dB, and for the judgement of rank order of sound insulation performance of the similar wall type while developing.

Guideline for managing research facilities and LMOs for R&D by the Act on transboundary movement of LMOs, etc,. (LMO법에 따른 연구시설의 운영 및 시험연구용 LMO의 관리)

  • Jang, Ho-Min
    • Journal of Plant Biotechnology
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    • v.35 no.1
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    • pp.5-12
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    • 2008
  • The transgenic technologies and their product (living modified organisms) have been developed and commercialized enough to get much attention in terms of their potentials to solve the current global difficulties such as shortage of food and energy. Furthermore, they are expected to make a big role in improving human health levels and creating bio-economy as innovative tools to pursue environmentally sound economic development. However, for the technologies and products to be developed and used in such a way that they continuously give a good impact to human society, first and foremost safety issues surrounding them should be dealt with. Every stage from in-house R&D, pilot field application to on the shelves should be managed to ensure safety following them because many consumers tend to have fear before they get the right or needed information on the modern biotechnology. In this sense, managing research facilities and LMOs for R&D from the point of safety is very crucial in that they are in the early stage of technology or product development. This paper especially deals with those to be complied with by researchers according to the Act on transboundary movement of LMOs, etc, entered into the effect from Jan. 1 2008.

A study on the correlation between V charpy absorbed energy and critical COD value in the welded parts of high tensil strength steel under various welding methods (고장력강 용접부에 있어서 한계 COD값과 V charpy충격치와의 상관성에 관한 연구)

  • 김영식;김충해
    • Journal of Advanced Marine Engineering and Technology
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    • v.12 no.3
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    • pp.57-67
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    • 1988
  • Although handicapped by the inability to bridge the size gap between small laboratory sample and large engineering component, the V charpy test sample method does possess certain advantages, such as each of preparation, simplicity of test method, speed, low cost in test machinery, and low cost per test. On the other hand, the COD test method does posses advantages, which reduce the size gap between the laboratory sample and actual engineering component. Consequently, the correlation between V charpy absorbed energy and the critical COD value is required for estimating critical COD value from the simple V charpy test results. In this paper, the high tensile strength steel AH36 plate specimens having a single edge cracked notch were investigated to find out the correlation between V charpy absorbed energy and critical COD value in the welded parts under such various welding methods as shielded metal arc welding, the submerged arc welding and the electro gas welding by means of V charpy impact test and static 3-point bending test. Main results obtained are as follow ; 1. The relationships between V charpy absorbed energy Wc' and critical COD value ($\delta_c$)show; $\delta_c$=0.0065 Wc'+0.1906. 2. Ductile- brittle transition behaviours can be estimated by means of fracture appearance and general yielding behaviours. 3. The V charpy absorbed energy of SMAW is higher than that of SAW, EGW and similar relationships are obtained in the COD tests.

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Epidemiological Aspects of Morbidity and Mortality from Cervical Cancer in Kazakhstan

  • Igissinov, Nurbek;Nuralina, Indira;Igissinova, Gulnur;Kim, Sergei;Moore, Malcolm;Igissinov, Saginbek;Khassenova, Zauresh
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.5
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    • pp.2345-2348
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    • 2012
  • Epidemiological studies of cancer incidence in Kazakhstan have revealed an uneven distribution for cervical cancer. Incidence and mortality rates were calculated for different regions of the republic, including the two major cities of Almaty and Astana, in 1999-2008. Defined levels for cartograms for incidence were low (up to 12.8/100,000), medium (12.8 to 15.9) and high (above 15.9) and for mortality were up to 7.1, 7.1 to 10.8 and more than 10.8, respectively. Basically high incidence rates were identified in the eastern, central and northern parts of the country and in Almaty. Such differences in cervical cancer data, and also variation in mortality/ incidence ratios, from a low of 0.4 in Almaty to a high of 0.71 in Zhambyl, point to variation in demographic and medical features which impact on risk and prognistic factors for cervical cancer in the country. Further research is necessary to highlight areas for emphasis in cancer control programs for this important cancer.

Performance of a Cross-Flow Fan with Various Stabilizer Positions and Rearguider Shapes (스태빌라이져 위치 및 리어가이더 형상변화에 따른 횡류홴의 성능특성 연구)

  • Kim, D.W.;Kim, H.S.;Yoon, T.S.;Park, S.K.;Kim, Yon J.
    • The KSFM Journal of Fluid Machinery
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    • v.7 no.4 s.25
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    • pp.7-15
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    • 2004
  • The design point of the cross-flow fan is generally based on the region within low static pressure and high flow rate. It relatively makes high dynamic pressure at low speed because a working fluid passes through an impeller blade twice. However, it has low static pressure efficiency between $30\%$ and $40\%$ because of relative high impact loss. The purpose of this study is to research the reciprocal relation among each parameter. Experiments and numerical analyses are conducted on effects of a stabilizer and a rearguider on performance analysis of a cross-flow fan. Two-dimensional, unsteady governing equations are solved using FVM, PISO algorithm, sliding grid system and standard $k-{\epsilon}$ turbulence model. Experiments are also carried out to estimate the performance of the modeled cross-flow fan. It is clarified that the rearguider of Archimedes type has excellent results for the most part.

A High-Performance Scalable ATM Switch Design by Integrating Time-Division and Space-Division Switch Architectures

  • Park, Young-Keun
    • Journal of Electrical Engineering and information Science
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    • v.2 no.6
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    • pp.48-55
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    • 1997
  • Advances in VLSI technology have brought us completely new design principles for the high-performance switching fabrics including ATM switches. From a practical point of view, port scalability of ATM switches emerges as an important issue while complexity and performance of the switches have been major issues in the switch design. In this paper, we propose a cost-effective approach to modular ATM switch design which provides the good scalability. Taking advantages of both time-division and space-division switch architectures, we propose a practically implementable large scale ATM switch architecture. We present a scalable shared buffer type switch for a building block and its expansion method. In our design, a large scale ATM switch is realized by interconnecting the proposed shared buffer switches in three stages. We also present an efficient control mechanism of the shared buffers, synchronization method for the switches in each stage, and a flow control between stages. It is believed that the proposed approach will have a significant impact on both improving the ATM switch performance and enhancing the scalability of the switch with a new cost-effective scheme for handling the traffic congestion. We show that the proposed ATM switch provides an excellent performance and that its cell delay characteristic is comparable to output queueing which provides the best performance in cell delay among known approaches.

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What Should Thoracic Surgeons Consider during Surgery for Ground-Glass Nodules?: Lymph Node Dissection

  • Kim, Hong Kwan
    • Journal of Chest Surgery
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    • v.54 no.5
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    • pp.342-347
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    • 2021
  • Thoracic surgeons need to be aware of several important points regarding intraoperative lymph node dissection during surgery for non-small cell lung cancer with ground-glass opacities. The first point relates to the need for lymph node dissection during sublobar resection. Since even patients undergoing sublobar resection may benefit from lymph node dissection, it should be selectively performed according to adequate indications, which require further study. Second, there seems to be no difference in postoperative morbidity between systematic sampling and systematic dissection, but the survival benefit from systematic dissection remains unclear. The results of randomized controlled trials on this topic are conflicting, and their evidence is jeopardized by a high risk of bias in terms of the study design. Therefore, further randomized controlled trials with a sound design should investigate this issue. Third, more favorable survival outcomes tend to be positively associated with the number of examined lymph nodes. Minimum requirements for the number of examined lymph nodes in non-small cell lung cancer should be defined in the future. Finally, lobe-specific lymph node dissection does not have a negative prognostic impact. It should not be routinely performed, but it can be recommended in selected patients with smaller, less invasive tumors. Results from an ongoing randomized controlled trial on this topic should be awaited.

Estimating Economic Optimum Planted Area for Sustainable Schisandra chinensis Cultivation

  • Lee, Byoung-Hoon
    • Journal of Forest and Environmental Science
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    • v.35 no.3
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    • pp.173-180
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    • 2019
  • This study determined the economic impact of environment-friendly cultivation and the optimal cultivation area of Omija (Korean for Schisandra chinensis Baillon) for full-time farmers by analyzing the management performance of existing Omija cultivators. The study divided the target income into urban household income and Omija farm income, and estimate the optimal cultivation area by substituting the target profit from the cost-volume-profit analysis model. The optimum cultivation area was 1.4 ha for general cultivation, 1.08 ha for organic cultivation, and 1.18 ha for pesticide-free farming cultivation considering the average urban household income as the target, and 0.81 ha for general cultivation, 0.63 ha for organic cultivation, and 0.69 ha for pesticide-free farming, considering the average 2012 farm household income as the target. Therefore, the study reached conclusion that it is necessary to secure the price of Omija farm and stable support for income increase. Therefore, the support plan for income stabilization of Omija farm should be considered. Especially, the central government should provide various policies and financial support to help the optimal cultivation area of Omija Farm.

Mediating and Moderating Mechanism in the Relationship Between Blue Ocean Leadership Style and Strategic Decision Making: A Case Study in Malaysia

  • WAN HANAFI, Wan Noordiana;DAUD, Salina
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.7
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    • pp.613-623
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    • 2021
  • This study aims to identify the effect of blue ocean leadership style on strategic decision making and it also aims to examine the mediating role of organizational politic and moderating role of emotional intelligence in the Government Link Companies (GLCs) in Malaysia. In order to achieve the objective of the study, a research framework had been developed to establish a relationship among the variables of the study based on resource-based view theory. Questionnaire method was used to collect the data form middle to top level employees in GLCs. All the items in the study's variables were assessed using the 5-point Likert scale. A stratified random sampling technique was used to identify the sample for this study. Data was derived from 135 middle to top level employees, which were involved in decision making process. The data was analyzed using the SPSS and the SmartPLS 3.0 software. This supplemented the theory surrounding blue ocean leadership styles and strategic decision making. The study also identified several avenues for further research by using different research methods and examining the impact of strategic decision making in different contexts.