• 제목/요약/키워드: Wales

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Nonlinear P-Δ analysis of steel frames with semi-rigid connections

  • Valipour, Hamid R.;Bradford, Mark A.
    • Steel and Composite Structures
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    • 제14권1호
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    • pp.1-20
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    • 2013
  • This paper presents the formulation for a novel force-based 1-D compound-element that captures both material and second order P-${\Delta}$ nonlinearities in steel frames. At the nodal points, the element is attached to nonlinear rotational and a translational springs which represent the flexural and axial stiffness of the connections respectively. By decomposing the total strain in the material as well as the generalised displacements of the flexible connections to their elastic and inelastic components, a secant solution strategy based on a direct iterative scheme is introduced and the corresponding solution strategy is outlined. The strain and slope of the deformed element are assumed to be small; however the equilibrium equations are satisfied for the deformed element taking account of P-${\Delta}$ effects. The formulation accuracy and efficiency is verified by some numerical examples on the nonlinear static, cyclic and dynamic analysis of steel frames.

Geometrically nonlinear elastic analysis of space trusses

  • Tin-Loi, F.;Xia, S.H.
    • Structural Engineering and Mechanics
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    • 제7권4호
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    • pp.345-360
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    • 1999
  • A general framework for the nonlinear geometric analysis of elastic space trusses is presented. Both total Lagrangian and finite incremental formulations are derived from the three key ingredients of statics, kinematics and constitutive law. Particular features of the general methodology include the preservation of static-kinematic duality through the concept of fictitious forces and deformations, and an exact description for arbitrarily large displacements, albeit small strain, that can be specialized to any order of geometrical nonlinearity. As for the numerical algorithm, we consider specifically the finite incremental case and suggest the use of a conventional, simple and flexible arc-length based method. Numerical examples are presented to illustrate and validate the accuracy of the approach.

Expression of lac and gal operons in Zymomonas mobilis

  • Cho, Dong-Wuk;Rogers, Peter L.;Delaney, Stephen F.
    • Journal of Microbiology and Biotechnology
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    • 제4권2호
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    • pp.155-159
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    • 1994
  • Two Zymomonas mobilis strains (ZM63 and ZM6307), containing both lactose and galactose operons, were constructed. $\beta$-Galactosidase and galactokinase assays indicated that both operons were expressed in both strains. The transport systems available for lactose uptake by Zymomonas mobilis were investigated using $^{14}C$-labelled lactose. After the outer membrane, which was considered to be a possible barrier to lactose uptake, was disrupted by treatment with EDTA and $Ca^{2+}$ ions, some increase in lactose uptake was observed in ZM6306 ($lac^+$) and ZM6307 ($lac^+\;gal^+$), but not in the parent, ZM6. This suggested that the outer membrane of Zymomonas mobilis acts as a barrier to lactose uptake to some degree, and also that the lactose permease is operational in Zymomonas mobilis.

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Controlled-stress rotational rheometry : An historical review

  • Barnes, Howard A.;Bell, Derek
    • Korea-Australia Rheology Journal
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    • 제15권4호
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    • pp.187-196
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    • 2003
  • The recent renaissance in controlled-stress rheometry has meant that more and more commercial models of this type of instrument have appeared in the (rheological) marketplace and many papers now deal with the results obtained by their use. It is therefore both timely and appropriate that this mode of rheometry should be reviewed for the sake of new and old users who are probably not be aware of its development. The history of controlled-stress measurements is therefore given, and the particular efforts of the late Jack Deer in the 1970s are chronicled, and then the later developments that have made it possible that such low torques can now be applied and such low rotational speeds measured. These have been mostly in the areas of air bearing and optical disc technologies. The typical results now obtained are illustrated.

Critical Success Factors for Malaysian SMEs and Large Companies in Commercializing Universities' R&D Outputs

  • Tam, Kok Chian;Chong, Aik Lee;Yee, Angelina Seow Voon;Tham, Joel Kah Marn
    • Asian Journal of Innovation and Policy
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    • 제8권3호
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    • pp.362-377
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    • 2019
  • Commercializing universities' R&D outputs is a major management challenge and there are limited studies to describe this phenomenon from the perspective of companies' management. Experiences of six small and medium size and four large companies' management's respondents are gathered through semi-structured face-toface interviews. Twelve critical success factors revealed by the respondents, namely R&D product and market readiness, good partnership with university, researcher's motivationand commitment, availability of resources, government support and motivation, control and ownership of intellectual property rights, university's management support, entrepreneurial culture in the university, an open communication and trusting relationship, researchers' skills, a risk taking attitude, and existence of performance measures as important to commercialize the universities' R&D outputs in Malaysia. The different views from the management of small and medium size, and large companies are also discussed in this study.

Analysis of capacity management of the intensive care unit in a hospital

  • Kim, Seung-Chul;Horowitz, Ira;Young, Karl K.;Buckley, Thomas A.
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 1997년도 추계학술대회발표논문집; 홍익대학교, 서울; 1 Nov. 1997
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    • pp.79-82
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    • 1997
  • A hospital's intensive care unit (ICU) is a limited and critical resource whose efficient utilization of capacity impacts on both the welfare of patients and the hospital's cost effectiveness. Decisions made in the ICU affect the operations of other departments. Yet, decision making in an ICU tends to be mainly subjective and lacking in clear criteria upon which to base any given decision. The study reviews the capacity utilization of one particular ICU, that of a public hospital in Hong Kong, and develops a computer simulation model to improve both the unit's capacity utilization and the quality of care provided to its patients.

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시드니만의 오존예측을 위한 도시대기질모델의 예비검사 (Preliminary Testing of an Urban Air Quality Model for Ozone Forecasting over the Sydney Basin)

  • Speer, Milton S.;Leslie, Lance M.
    • 한국환경과학회지
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    • 제13권8호
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    • pp.733-737
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    • 2004
  • FThe aim of this study was to carry out a preliminary test of the air quality modelling system (HIRES-AIRCHEM) developed at The University of New South Wales, particularly with regard to the forecast ozone distribution. This was achieved by assimilating the New South Wales State Environment Protection Authority (EPA) emissions inventory, consisting of road and non-road sources, and running the system over the Sydney metropolitan area for the four day period 25-28 February 1998. During this period ozone readings exceeded the EPA's goal of 8pphm on several occasions. The model forecasts of ozone distribution verified well with the EPA's ozone readings. This result has important implications for possible future use of the system as a tool for routinely predicting and assessing air quality.