• Title/Summary/Keyword: Expansion mechanism

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An Analytical Solution of Progressive Wave-Induced Residual Pore-Water Pressure in Seabed (진행파동장하 해저지반내 잔류간극수압의 해석해)

  • Lee, Kwang-Ho;Kim, Dong-Wook;Kim, Do-Sam;Kim, Tae-Hyung;Kim, Kyu-Han;Ryu, Heung Won
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.27 no.3
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    • pp.159-167
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    • 2015
  • In this paper, the errors found in the existed analytical solutions described the mechanism of residual pore-water pressure accumulation were examined and a new analytical was proposed. The new analytical solution was derived by using a Fourier series expansion and separation of variables was verified by comparison with the existed both analytical and numerical solutions and experimental result. The new analytical solution is very simple that there is no need for numerical integration for deep soil thickness. In addition, the solutions of the residual pore-water pressure for finite, deep, and shallow soil thickness reveled that it is possible to approach from finite to shallow soil thickness, but not possible to deep soil thickness because there was discontinues zone between finite and deep soil thickness.

A Study on the Effect of the Stemming Hole medium to the Blasting Separation Distance of Structure (공내 매질이 구조물의 발파이격거리에 미치는 영향에 관한 연구)

  • Kang, Hee-Seop;Jeong, Jung-Gyu;Bang, Myung-Seok
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.1
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    • pp.100-108
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    • 2017
  • Because of urbanization, Industrialization and expansion of transportation network, blasting works are recently increasing in construction field. The blasting work influences environmental effects to residents and the safety of facilities around the working place, so the development of blasting technology is needed to reduce the damage to residents. The blasting mechanism in the hole was studied and tested in the blasting sites by the difference of diameter between explosives and drilling hole, which is named by the decoupling effect. This effect was tested by changing the medium between explosives and hole wall in three working sites(railway, highway and industrial complex). The vibration velocity of blasting was recorded and vibration equations were produced by regression analyses. Finally, the structure separation distance was derived using these equations. The testing results show that the specific gravity of medium is larger, the separation distance is smaller and the duration time of blasting is shorter in case of large specific gravity of medium, so the vibration effect stops more fastly in the water compared with the air.

A Case of Postpneumonectomy Syndrome Treated with Endobronchial Stent (기관지 스텐트 삽입으로 치료한 전폐절제술후 증후군 1예)

  • Jeong, Seong-Hyun;Cho, Hye-Jin;Lee, Hyoung-No;Lee, Hyung-Sook;Sheen, Seung-Soo;Oh, Yoon-Jung;Park, Kwang-Joo;Hwang, Sung-Chul;Won, Jae-Hwan;Park, Kyung-Joo
    • Tuberculosis and Respiratory Diseases
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    • v.53 no.3
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    • pp.325-331
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    • 2002
  • Postpneumonectomy syndrome is a rare complication that usually occurs in younger patients within the first year after a right total lung resection. Its clinical presentations are stridor, dyspnea, and recurrent pulmonary infections. An airway obstruction secondary to the extreme mediastinal shift and ratation after a pneumonectomy is the main mechanism. It is commonly complicated with tracheobronchomalacia due to longstanding airway compression. The management modalities involve a repositioning of the mediastinum with volume expansion of the pneumonectomy site by a expandable prosthesis. however, other methods including an endobronchial stent insertion should be considered in the presence of a tracheobronchomalacia or in poor surgical candidates. Here we describe a case of postpneumonectomy syndrome complicated by a bronchomalacia, which was successfully treated with a self-expandable endobronchal stent.

Myotube differentiation in clustered regularly interspaced short palindromic repeat/Cas9-mediated MyoD knockout quail myoblast cells

  • Kim, Si Won;Lee, Jeong Hyo;Park, Byung-Chul;Park, Tae Sub
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.7
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    • pp.1029-1036
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    • 2017
  • Objective: In the livestock industry, the regulatory mechanisms of muscle proliferation and differentiation can be applied to improve traits such as growth and meat production. We investigated the regulatory pathway of MyoD and its role in muscle differentiation in quail myoblast cells. Methods: The MyoD gene was mutated by the clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 technology and single cell-derived MyoD mutant sublines were identified to investigate the global regulatory mechanism responsible for muscle differentiation. Results: The mutation efficiency was 73.3% in the mixed population, and from this population we were able to establish two QM7 MyoD knockout subline (MyoD KO QM7#4) through single cell pick-up and expansion. In the undifferentiated condition, paired box 7 expression in MyoD KO QM7#4 cells was not significantly different from regular QM7 (rQM7) cells. During differentiation, however, myotube formation was dramatically repressed in MyoD KO QM7#4 cells. Moreover, myogenic differentiation-specific transcripts and proteins were not expressed in MyoD KO QM7#4 cells even after an extended differentiation period. These results indicate that MyoD is critical for muscle differentiation. Furthermore, we analyzed the global regulatory interactions by RNA sequencing during muscle differentiation. Conclusion: With CRISPR/Cas9-mediated genomic editing, single cell-derived sublines with a specific knockout gene can be adapted to various aspects of basic research as well as in functional genomics studies.

On the Occurrence Mechanism of the Ice Spike (솟는 고드름의 형성 원리)

  • Byun, Hi-Ryong;Yoon, Ma-Byong;Shim, Jae-Myun;Kim, Gabyn;Kwon, Sang-Hoon;Kwon, Hui-nae;Kim, Jin-Ah
    • Atmosphere
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    • v.26 no.1
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    • pp.73-84
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    • 2016
  • A method to make ice spike using home refrigerator with ice tray was found. Many experiments have carried out with this method and many natural phenomena occurring on the formation of ice spike are found. A new concept of the Latter Freezing Water (LFW) was imported to explain the ice spike formation. At LFW position on water surface, the Sprout of Super cooled Water (SSW) grows by the Volume Expansion Effect (VEE) caused by the phase change of water in water. And air bubbles that are expelled from ice during freezing process, gather, rise, and detonate at the upper most part of SSW that make SSW freeze and grow upward with the water pipe in it. Together with VEE the capillarity in the water pipe makes the column grow more, that makes the ice spike. Many other findings were succeeded; 1) Ice spike process is completed before the whole water freezes. 2) If water is corrupted or shocked, even though it is very slight, ice spike is not generated. 3) Rain water contains the most LFW among all kind of waters used in experiments. 4) LFW is changed into normal water after passing the ice spike. 5) A new concept of the ice bullet is introduced. 6) The reason of frequent occurrences of the ice spike at Mt. Mai is investigated also.

Wolsong Unit 1 Steam Generator Aging Management for Continued Operation (월성 1호기 계속운전을 위한 증기발생기 열화관리)

  • Song, Myung Ho;Kim, Hong Key;Lee, Jung Min
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.6 no.2
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    • pp.28-33
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    • 2010
  • As a part of license renewal for the continued operation of Wolsong unit 1, the periodic safety review report was submitted near the end of design lifetime, 2012, and now is under reviewing. Major components of primary system such as pressure tubes, feeder pipes and so on are being replaced and many components of secondary system are also being repaired. So the license renewal of Wolsong unit 1 is expected to be acquired without significant issues. But on the other hand, steam generators of Wolsong unit 1 had the good performance and therefore the replacement and repair for the steam generator are not needed. Recently it is reported that some cracks were detected in a few of european steam generator with Alloy 800 tubes and the cause of cracks was the outer diameter stress corrosion cracking(ODSCC) due to the concentration of chemical impurities on the outer surface of tube. Accordingly the overall review on this issue was performed. The long-term operation is likely to results to form the concentration mechanism for the tube corrosion as the sludge build-up in the secondary side of steam generator and the crack in the crevice between tube and tube-sheet and expansion transitions is apt to be occurred. In this paper, the history of steam generator inspection and operation of Wolsong unit 1 are reviewed and the reliability of steam generator tube is evaluated and the steam generator aging management program for Wolsong unit 1 is introduced.

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Nonlinear Tensile Behavior Analysis of Torque-controlled Expansion Anchors Using Finite Element Analysis (유한요소해석을 활용한 비틀림 제어 확장앵커의 비선형 인장거동 특성 분석)

  • Bang, Jin Soo;Youn, Ilro;Kwon, Yangsu;Yim, Hong Jae
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.4
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    • pp.91-99
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    • 2020
  • Post-installed anchors were widely used due to its workable benefits. Regarding the resistance performance of anchors, the critical edge distance is presented to minimize the impact of concrete splitting. In the case of actual anchors, however, it is difficult to obtain the ideal edge distance. The purpose of this study is to identify resistance performance and behavior characteristics that contain complex elements such as concrete crack occurring under tensile load. Tensile tests were conducted based on the standard method. Failure shape and the resistance characteristics that do not have the critical edge distance were derived by tensile load. Parametric analysis according to the boundary condition was performed to simulate the actual tensile behavior, through a nonlinear finite element model based on the specimen. Consequently therefore, verifying analysis results the resistance mechanism can be applied through boundary conditions.

A New R-IPC Protocol for a High-speed Router System to Improve the System Performance (고속 대용량 라우터의 성능 향상을 위한 R-IPC프로토콜 성능분석)

  • 김수동;조경록
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.6
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    • pp.1096-1101
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    • 2004
  • By a tremendous expansion of Internet users, there's a number effects that cause the phenomenon of bottlenecked switching packets from routers. In order to tear down this problem, distributed system is applicable to almost every highly performed router systems. The main processor of distributed system, which manages routing table, commands IPC to delivering the forwarding table line processor that eases functionalities of the router. This makes the system having wired-speed forwarding function based on the hardware so that the performance of the network can be enhanced. Therefore, IPC, which assign a part of router, is necessary to exchange data smoothly and the constitution of IPC using Ethernet is widely adapted as a method for saving investment. In this paper, R-IPC mechanism improve the packet-processing rate over 10% through changed from defect of conventional Ethernet IPC, that is, 2 layer processing to TCP/IP or UDP/ IP into 1 layer processing for efficient packet forwarding.

A Study on Fisheries Resource Management Under the Rate Payment System - In Case of Large Trawl Fisheries - (비율(보합) 급제하에서 어업(자원)관리에 관한 연구 - 대형기선저인망어업을 중심으로 -)

  • Park Seong-Kwae
    • The Journal of Fisheries Business Administration
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    • v.36 no.3 s.69
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    • pp.1-24
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    • 2005
  • Korean fishery wage system has been evolved with the different titles. However, Since the law of fishing crew was enacted in 1984, the fishery wage system has been established as a rate system, which is a legal term. The present rate system in practice shows various contents and modalities, depending on fisheries and regions, but the fisheries of large trawl cooperative employ a rate system of fixed plus rate wage. However, such change did not transform basically the properties of pure rate scheme. As well known, fishing vessel owners face an awful lot of difficulty in managing and controlling effectively the production process because fishing activities are carried out in the seas remote from the land. Thus, it tend to be inevitable for vessel owners to employ a rate system to induce fishermen's positive motivation for promoting productivity and saving operating costs. However, the rate system has worked out as a driving force, which induce an increase in production more strongly under the expansion of vessel numbers and power and the keener competition of fishing activities. Even though the control mechanism of fishing instruments are well established, fishermen become naturally to have an incentive to increase their fishing effort for maximizing production since they are able to raise their shares by maximizing the quantity harvested. Thus, as far as the rate system exists, fisheries administration may have much difficulty in realizing its fishery management goals only through vessel reduction and fishing gear regulations. Also, under the rate system fishery management authority may be in face of a serious dilemma between the spontaneous rate system and vessel reduction policy. If the realistic aspect of the rate system is recognized and resource restoration and profit promotion are main policy goals, it is necessary to develop effective ways to control vessel owners' and fishermen's production-maximizing motives at an appropriate level. From this point of view, it seems reasonable to introduce TAC system by species or by fisheries into the existing fishery system. The research results suggest that if the fisheries administration could understand clearly the spontaneous fisheries wage system, it would know the norm of TAC and the basic reasons for illegal fishing activities and thus it would be able to develop and implement more realistic resource management policies.

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Research on Improving the Supporting System for Experiential Environmental Education Programs Funded by Ministry of Environment (환경부의 체험환경교육 프로그램 지원 사업 개선 방안 연구)

  • Lee Jae-Young;Kim In-Ho;Lee Sun-Kyung;Kim Dae-Hee;Cheong Cheol;Kim Nam-Soo;Kim Soo-Yeon;Jung Sue-Jung;Cho Eun-Jeong;Choi In-Mi
    • Hwankyungkyoyuk
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    • v.19 no.1 s.29
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    • pp.30-42
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    • 2006
  • The Ministry of Environment supports environmental education mainly in two ways ; one is by supporting schools engaged in environment conservation model school and the other is by extending grants for experiential environmental education programs. This research aims to evaluate the current status of grant for experiential environmental education programs while proposing possible improvement for constructive and continuing development of the support measures. Grant for experiential environmental education programs is divided into two areas of grant for schools and grant for community-based civil organizations. The diagnosis and evaluation were conducted in terms of 7 areas, such as time, facilities, programs, manpower (professional expertise), operation, administrative and financial support mechanism and others. Research process involved the review of previous studies in 2001 and 2003, comparison of the grant program with other grants in and out of Korea for environment education, and the following areas considered when identifying improvement options: i) Overall review of objectives and operations, ii) expansion supports programs oriented problem solving as well as those focused ecological sensitivity, iii) change from expendable, one-time program to productive, continuous program, iv) link to social changes and issues, v) principles for operation and evaluation, vi) criteria and methods for program selection and evaluation, and vii) improving operation system. Based on review and the overall evaluation on the experiential environmental education program grant, the recommendation for improving operation system were provided, which included stages of passive improvement, active improvement and building infrastructure for environment education, and building capacity of the members related in the initiatives.

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