• Title/Summary/Keyword: retaining capability

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Modelling of Oil Boom Failure using the Fluent (Fluent를 이용한 오일 붐 누유 모델링)

  • Bae, Suk-Han;Jung, Yun-Chul
    • Journal of Navigation and Port Research
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    • v.27 no.2
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    • pp.239-246
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    • 2003
  • When oil is spilled at sea, the oil boom is commonly used to tackle the movement and spreading of oil in an early stage of oil spill combat. But the retaining capability of oil boom is affected by various factors, such as water velocity, viscosity and density of oil, water depth, oil volume and the length of boom draft. In this study, a computer modelling was peformed to investigate how these factors influence the oil retaining process. The Fluent, most popular one of many CFD(computational fluid dynamics) programs is chosen for modelling and modelling results were verified using the empirical data. It is expected that results of this study will be useful data for oil boom designer and oil spill response commander.

Modelling of Oil Boom Failure using the Fluent (Fluent를 이용한 오일 붐 누유 모델링)

  • 배석한;정연철
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2003.05a
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    • pp.171-178
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    • 2003
  • When oil is spilled at sea, the oil boom is commonly used to tackle the movement and spreading of oil in an early stage of oil spill combat. But, the retaining capability of oil boom is affected by various factors, such as water velocity, viscosity, and density of oil, water depth, oil volume and the length of boom draft. In this study, computer modeling was peformed to investigate how these factors influence the oil retaining process. The Fluent, most popular one of many CFD(computational fluid dynamics) programs is chosen for modelling and modelling results were verified using the empirical data. It is expected that results of this study will be useful data for oil boom designer and oil spill response commander.

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Temperature History of the Concrete for Retaining Wall Insulated with Double Layered Bubble Sheet in Summer (서중기 2중버블시트로 단열처리된 옹벽의 온도이력 특성)

  • Jung, Eun-Bong;Kim, Kyung-Hun;Jang, Deok-Bae;Kyung, Yeong-Hyeok;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.11a
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    • pp.45-46
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    • 2012
  • This study is intended to use the insulation effect of the dual bubble sheet to review the freezing prevention capability of underground walls by pouring the dual bubble sheet on the retaining walls before the concrete pouring to contemplate the temperature profile for each area of installation and the area of non-installation of the dual bubble sheet, and as a result, the temperature of the concrete was heightened than the ground due to the insulation effect in using the bubble sheet.

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Evaluation of Dynamic Stability for Structural Bar Reinforced Precast and Prestressed Retaining Wall for Moving Train Load (이동열차하중에 대한 강봉으로 보강된 프리캐스트 프리스트레스트 옹벽의 동적 안정성 평가)

  • Lee, Il Wha;Um, Ju Hwan;Lee, Kang Myung;Keum, Chang Jun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.5
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    • pp.190-198
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    • 2011
  • The precast production has many advantages by fast construction period, labor-saving and high quality. In recent years, the application of the precast product has been increased in the earth retaining wall field. This paper presents the results of the numerical analysis that was carried out to evaluate the dynamic stability of precast and prestressed earth retaining wall under moving train load. The two-dimensional FEM analysis was used to the numerical analyses. The train load to act on trackbed is combined by the real measured roughness phase angle and quasi-static load. The dynamic stability is analysed by the displacement, acceleration and stress under moving train load at each specified location. The results of the analysis show that the precast and prestressed retaining wall has very stable capability for the railway.

Organizational Capabilities for Effective Knowledge Creation: An In-depth Case Analysis of Quinolone Antibacterial Drug Discovery Process (효과적 지식창출을 위한 조직능력 요건: 퀴놀론계 항생제 개발 사례를 중심으로)

  • Lee, Chun-Keun;Kim, Linsu
    • Knowledge Management Research
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    • v.2 no.1
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    • pp.109-132
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    • 2001
  • The purpose of this article is to develop a dynamic model of organizational capabilities and knowledge creation, and at the same time identify the organizational capability factors for effective knowledge creation, by empirically analyzing the history of new Quinolone antibacterial drug compound (LB20304a) discovery process at LG, as a case in point. Major findings of this study are as follows. First, in a science-based area such as drug development, the core of successful knowledge creation lies in creative combination of different bodies of scientific explicit knowledge. Second, the greater the difficulty of learning external knowledge, the more tacit knowledge is needed for the recipient firm to effectively exploit that knowledge. Third, in science-based sector such as pharmaceutical industry, the key for successful knowledge creation lies in the capability of recruiting and retaining star scientists. Finally, for effective knowledge creation, a firm must keep its balance among three dimensions of organizational capabilities: local, process, architectural capabilities.

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Characteristics and prediction methods for tunnel deformations induced by excavations

  • Zheng, Gang;Du, Yiming;Cheng, Xuesong;Diao, Yu;Deng, Xu;Wang, Fanjun
    • Geomechanics and Engineering
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    • v.12 no.3
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    • pp.361-397
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    • 2017
  • The unloading effect from excavations can cause the deformation of adjacent tunnels, which may seriously influence the operation and safety of those tunnels. However, systematic studies of the deformation characteristics of tunnels located along side excavations are limited, and simplified methods to predict the influence of excavations on tunnels are also rare. In this study, the simulation capability of a finite element method (FEM) considering the small-strain characteristics of soil was verified using a case study. Then, a large number of FEM simulations examining the influence of excavations on adjacent tunnels were conducted. Based on the simulation results, the deformation characteristics of tunnels at different positions and under four deformation modes of the retaining structure were analyzed. The results indicate that the deformation mode of the retaining structure has a significant influence on the deformation of certain tunnels. When the deformation magnitudes of the retaining structures are the same, the influence degree of the excavation on the tunnel increased in this order: from cantilever type to convex type to composite type to kick-in type. In practical projects, the deformation mode of the retaining structure should be optimized according to the tunnel position, and kick-in deformation should be avoided. Furthermore, two methods to predict the influence of excavations on adjacent tunnels are proposed. Design charts, in terms of normalized tunnel deformation contours, can be used to quantitatively estimate the tunnel deformation. The design table of the excavation influence zones can be applied to determine which influence zone the tunnel is located in.

A load-bearing structural element with energy dissipation capability under harmonic excitation

  • Pontecorvo, Michael E.;Barbarino, Silvestro;Gandhi, Farhan S.;Bland, Scott;Snyder, Robert;Kudva, Jay;White, Edward V.
    • Advances in aircraft and spacecraft science
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    • v.2 no.3
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    • pp.345-365
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    • 2015
  • This paper focuses on the design, fabrication, testing and analysis of a novel load-bearing element with energy dissipation capability. A single element comprises two von-Mises trusses (VMTs), which are sandwiched between two plates and connected to dashpots that stroke as the VMTs cycle between stable equilibrium states. The elements can be assembled in-plane to form a large plate-like structure or stacked with different properties in each layer for improved load-adaptability. Also introduced in the elements are pre-loaded springs (PLSs) that provide high initial stiffness and allow the element to carry a static load even when the VMTs cannot under harmonic disturbance input. Simulations of the system behavior using the Simscape environment show good overall correlation with test data. Good energy dissipation capability is observed over a frequency range from 0.1 Hz to 2 Hz. The test and simulation results show that a two layer prototype, having one soft VMT layer and one stiff VMT layer, can provide good energy dissipation over a decade of variation in harmonic load amplitude, while retaining the ability to carry static load due to the PLSs. The paper discusses how system design parameter changes affect the static load capability and the hysteresis behavior.

Analysis of Individual Capability Factors to Improve Business Performance in the Environment of Technological Convergence (융합기술 환경에서 기업성과 향상을 위한 개인역량요인 분석)

  • Kang, Su-Hyun;Lee, Hong-Joo;Leem, Choon-Seong
    • The Journal of Society for e-Business Studies
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    • v.15 no.3
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    • pp.183-193
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    • 2010
  • Corporate business environment is rapidly evolving with the dramatic development of Information Technology. On that regard, companies are exploring various ways to create values in a bidto deliver outstanding business performance as well as coping with a changing business environment. Companies, in addition, have exerted extra efforts in developing and retaining talents as a way to enhance business performance. Against the backdrop, this paper presents a research-analysis model to analyze capability factors of corporate members which are essential for a company to create more values in the rapidly changing business environment. To this end, this paper carried out the following researches : First, through a literature review, capability types, which are required to improve business performance, as well as individual capability factors, were analyzed. Second, based on analysis result, Attitude, Skill and Knowledge were presented as individual capability factors essential to the technological convergence environment. Third, to analyze the validity of the research analysis model, expert interviews with corporate human resource as well as a large scale survey were performed.

Building Customer Loyalty with Trust and Familarity in the Internet-based Shopping-mall (인터넷쇼핑몰에서 신뢰와 친밀감이 고객충성도에 미치는 영향에 관한 연구)

  • Ko, Il-Sang;Choi, Su-Jeong
    • Asia pacific journal of information systems
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    • v.15 no.3
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    • pp.187-207
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    • 2005
  • In the Internet-based B2C e-commerce, trust has been recognized as a critical factor to reduce uncertainties, through interacting with a well-known specific shopping mall. In this study, we view customer trust as not a unitary concept but multidimensional one consisted of the trustworthiness of trustee, familiarity with the specific shopping-mall, disposition to trust, and institution-based trust. In this study, first, we considered the trustworthiness of trustee consisted of capability, benevolence, and integrity as one of the major factors to build customer trust on the specific Internet shopping-mall. In the context of the Internet e-commerce, the role of institutional structures is very important to assure the customer trust from the various opportunistic behaviors because of the characteristics of internet-based commerce such as impersonality, the lack of information on the other party, and the transactions with a number of anonymous people. Second, we examined the effect of the institution-based trust built by institutional structures on customer trust. Third, we examined the effect of customer trust and familiarity on retaining customer loyalty. Our findings showed that customer trust and familiarity played a major role in retaining customer loyalty with the specific shopping-mall. In conclusions, we discussed the strategies to build the customer loyalty for maintaining the customer. We suggest customer trust and familiarity for the factors to bind the customer with the specific shopping-mall based on these results.

Investigation of gamma radiation shielding capability of two clay materials

  • Olukotun, S.F.;Gbenu, S.T.;Ibitoye, F.I.;Oladejo, O.F.;Shittu, H.O.;Fasasi, M.K.;Balogun, F.A.
    • Nuclear Engineering and Technology
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    • v.50 no.6
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    • pp.957-962
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    • 2018
  • The gamma radiation shielding capability (GRSC) of two clay-materials (Ball clay and Kaolin)of Southwestern Nigeria ($7.49^{\circ}N$, $4.55^{\circ}E$) have been investigated by determine theoretically and experimentally the mass attenuation coefficient, ${\mu}/{\rho}(cm^2g^{-1})$ of the clay materials at photon energies of 609.31, 1120.29, 1173.20, 1238.11, 1332.50 and 1764.49 keV emitted from $^{214}Bi$ ore and $^{60}Co$ point source. The mass attenuation coefficients were theoretically evaluated using the elemental compositions of the clay-materials obtained by Particle-Induced X-ray Emission (PIXE) elemental analysis technique as input data for WinXCom software. While gamma ray transmission experiment using Hyper Pure Germanium (HPGe) spectrometer detector to experimentally determine the mass attenuation coefficients, ${\mu}/{\rho}(cm^2g^{-1})$ of the samples. The experimental results are in good agreement with the theoretical calculations of WinXCom software. Linear attenuation coefficient (${\mu}$), half value layer (HVL) and mean free path (MFP) were also evaluated using the obtained ${\mu}/{\rho}$ values for the investigated samples. The GRSC of the selected clay-materials have been compared with other studied shielding materials. The cognizance of various factors such as availability, thermo-chemical stability and water retaining ability by the clay-samples can be analyzed for efficacy of the material for their GRSC.