Spelling suggestions: "subject:"3structure design"" "subject:"1structure design""
1 |
Limit and shakedown analysis of structures by the finite element methodShi, Jinhua January 1996 (has links)
Limit and shakedown analyses are powerful methods in designing pressure vessel components and other engineering structures. With the development of computer technology the use of finite element analysis as an alternative tool for engineering structure design has become ever more increasing. In this thesis the finite element method utilises the novel elastic compensation method to carry out the limit and shakedown analyses on variety engineering structures: nozzles in pressure vessels, plates with a central hole and frame structures. There are two main objectives of the present study. One of them is to conduct limit and shakedown analyses on a series of thick cylinders, nozzle/sphere intersections under internal pressure, plates with a hole and frame structures under multiple loading conditions using the initially developed elastic compensation method based on 2-D solid element models. A comparision of the lower, upper bound limit loads and shakedown solutions is made with the result s available in literature or with new elasto-plastic analyses. The results obtained using the elastic compensation method were found to be of useful accuracy. Another is to further develop the elastic compensation method using generalised yield criteria. Then the procedure is implemented to beam and shell finite elements to calculated limit loads for beam and shell structures. A number of 2-D and 3-D frames were examined using a general yield surface. The obtained results were compared with that of theoretical plastic analysis and with the results available in literature and were found to be in good agreement. Parametric studies of nozzle/sphere intersections and nozzle/cylinder intersections under internal pressure were carried out using Ilyushin's and Ivanov's generalised yield criteria. The results calculated were compared with the solutions obtained using the initially elastic compensation method and with the solutions available in literature and were found to also be in good agreement. The newly developed elastic compensation procedure using generalised yield criteria was found to be more economic and useful in engineering design. From this study, some new design methods based on limit and shakedown loads are proposed for nozzle/sphere intersections and for other engineering structures. The newly developed elastic compensation procedure using generalised yield criteria is highly recommended in structural design for a quick limit load estimation.
|
2 |
The experimental behaviour of double skinned composite and reinforced concrete shells subjected to external hydrostatic pressureNash, T. January 1987 (has links)
No description available.
|
3 |
Nonlinear analysis and design of R/C coupled wall systems subjected to earthquakeChaallal, O. January 1983 (has links)
No description available.
|
4 |
Planning in constraint space for multi-body manipulation tasksErdogan, Can 27 May 2016 (has links)
Robots are inherently limited by physical constraints on their link lengths, motor torques, battery
power and structural rigidity. To thrive in circumstances that push these limits, such as in search
and rescue scenarios, intelligent agents can use the available objects in their environment as
tools. Reasoning about arbitrary objects and how they can be placed together to create useful
structures such as ramps, bridges or simple machines is critical to push beyond one's physical
limitations. Unfortunately, the solution space is combinatorial in the number of available objects
and the configuration space of the chosen objects and the robot that uses the structure is high
dimensional.
To address these challenges, we propose using constraint satisfaction as a means to test the
feasibility of candidate structures and adopt search algorithms in the classical planning literature
to find sufficient designs. The key idea is that the interactions between the components of a
structure can be encoded as equality and inequality constraints on the configuration spaces of the
respective objects. Furthermore, constraints that are induced by a broadly defined action, such as
placing an object on another, can be grouped together using logical representations such as Planning
Domain Definition Language (PDDL). Then, a classical planning search algorithm can reason about
which set of constraints to impose on the available objects, iteratively creating a structure that
satisfies the task goals and the robot constraints. To demonstrate the effectiveness of this
framework, we present both simulation and real robot results with static structures such as ramps,
bridges and stairs, and quasi-static structures such as lever-fulcrum simple machines.
|
5 |
An investigation into the fatigue behaviour of wood : Laminates for Wind Energy Converter blade designTsai, K. T. January 1987 (has links)
No description available.
|
6 |
Statistics for offshore extremesRobinson, Michael E. January 1997 (has links)
No description available.
|
7 |
Optimal designs for maximum likelihood estimation and factorial structure designChowdhury, Monsur 06 September 2016 (has links)
This thesis develops methodologies for the construction of various types of optimal designs with applications in maximum likelihood estimation and factorial structure design. The methodologies are applied to some real data sets throughout the thesis.
We start with a broad review of optimal design theory including various types of optimal designs along with some fundamental concepts. We then consider a class of optimization problems and determine the optimality conditions. An important tool is the directional derivative of a criterion function. We study extensively the properties of the directional derivatives. In order to determine the optimal designs, we consider a class of multiplicative algorithms indexed by a function, which satisfies certain conditions. The most important and popular design criterion in applications is D-optimality. We construct such designs for various regression models and develop some useful strategies for better convergence of the algorithms.
The remaining thesis is devoted to some important applications of optimal design theory. We first consider the problem of determining maximum likelihood estimates of the cell probabilities under the hypothesis of marginal homogeneity in a square contingency table. We formulate the Lagrangian function and remove the Lagrange parameters by substitution. We then transform the problem to one of maximizing some functions of the cell probabilities simultaneously. We apply this problem to some real data sets, namely, a US Migration data, and a data on grading of unaided distance vision. We solve another estimation problem to determine the maximum likelihood estimation of the parameters of the latent variable models such as Bradley-Terry model where the data come from a paired comparisons experiment. We approach this problem by considering the observed frequency having a binomial distribution and then replacing the binomial parameters in terms of optimal design weights. We apply this problem to a data set from American League Baseball Teams.
Finally, we construct some optimal structure designs for comparing test treatments with a control. We introduce different structure designs and establish their properties using the incidence and characteristic matrices. We also develop methods of obtaining optimal R-type structure designs and show how such designs are trace, A- and MV-optimal. / October 2016
|
8 |
Controlling the structure of peptide using ferrocene as a molecular scaffoldChowdhury, Somenath 14 June 2007
The de novo design of peptides is a central area of research in chemical biology. Although it is now possible to design helical peptide structures from first principle, designing â-sheets remains a challenge. Significant advances in this area have been made by using molecular scaffolds, which stabilize â-sheets through intramolecular H-bonding involving the scaffold or which direct supramolecular assembly of the conjugate. In my thesis, I have made use of novel strategies, using ferrocene (Fc) as a central scaffold for controlling the secondary structure of peptides. This approach has been highly successful. Four major new strategies are introduced and described in this thesis: <p>a) Cyclization of Fc-peptide conjugates of the type Fc[CO-Xxx-CSA]2 (Xxx = Gly, Ala, Val, Leu) and Fc[CO-Gly-Xxx-CSA]2 (Xxx = Val, Ile; CSA = cysteamine) leads to the clean formation of novel cyclic bioorganometallic conjugates, which exhibit strong intramolecular hydrogen bonding interactions that restrict the mobility of the podand peptide chains. In the latter system, this intermolecular hydrogen bonding interaction was exploited for the design of a novel â-barrel-like structure. For Fc[CO-Gly-Val-CSA]2 and Fc[CO-Gly-Ile-CSA]2 discrete cyclic supramolecular assemblies were formed in which the individual molecules assemble along the rims of the molecules, resulting in the formation of tubular peptide superstructures that possess a central cavity and are filled with water molecules. <p>b) Prior to my work, work by Hirao and Metzler-Nolte clearly showed that the two podand peptide chains in Fc-peptide conjugates are pointing away from each other. This would indicate that extended â-sheets cannot be formed by simply extending the podand peptide chains. In my work, I clearly demonstrate that, in contrast to earlier results, it is possible to use the Fc scaffold to stabilize â-sheet-like interactions in longer peptide chains. Two systems are described in this thesis Fc[CO-Gly-Val-Cys(Bz)-OMe]2 and Fc[CO-Gly-Ile-Cys(Bz)-OMe]2. In both the cases, amino acids are employed that have a high propensity for â-sheet formation. Both Fc-peptide conjugates exhibit strong interstrand hydrogen bonding, resembling that found in â-sheets.<p>c) In this work, I have demonstrated the use of ferrocene amino acid (Fca) to control the structure in peptides. In contrast to previous work by Metzler-Nolte, my work is largely focusing on the design of a repetitive Fca-peptide motif. It is proposed that this repetition will enable strong interactions between the peptide portions of the conjugate, resulting in the formation of an extended structure. To this effect, a series of Fca-conjugates of the type Boc-[Fca-Ala]n-OMe (n = 1-4) was synthesized and fully characterized. All systems display the expected interaction between the Ala residues having a 12-membered hydrogen bonded ring. Such a structural motif resembles that found in naturally occurring â-helical structures of the spike-region of some viral proteins. <p>d) I have also demonstrated the use of a novel Fc-derivative, Fc[NH-Boc]2, to control the structure of podand amino acid chains. Fc-diamine was synthesized by the convenient carbazide route giving this useful scaffold in high yield. This material was converted into its peptide conjugate and the resulting conjugate displays the elusive 14-membered hydrogen bonding ring. <p>Thus, in my work, I have provided a new complementary tool for peptide design that will undoubtedly find applications for the design of de novo proteins in the near future.
|
9 |
Controlling the structure of peptide using ferrocene as a molecular scaffoldChowdhury, Somenath 14 June 2007 (has links)
The de novo design of peptides is a central area of research in chemical biology. Although it is now possible to design helical peptide structures from first principle, designing â-sheets remains a challenge. Significant advances in this area have been made by using molecular scaffolds, which stabilize â-sheets through intramolecular H-bonding involving the scaffold or which direct supramolecular assembly of the conjugate. In my thesis, I have made use of novel strategies, using ferrocene (Fc) as a central scaffold for controlling the secondary structure of peptides. This approach has been highly successful. Four major new strategies are introduced and described in this thesis: <p>a) Cyclization of Fc-peptide conjugates of the type Fc[CO-Xxx-CSA]2 (Xxx = Gly, Ala, Val, Leu) and Fc[CO-Gly-Xxx-CSA]2 (Xxx = Val, Ile; CSA = cysteamine) leads to the clean formation of novel cyclic bioorganometallic conjugates, which exhibit strong intramolecular hydrogen bonding interactions that restrict the mobility of the podand peptide chains. In the latter system, this intermolecular hydrogen bonding interaction was exploited for the design of a novel â-barrel-like structure. For Fc[CO-Gly-Val-CSA]2 and Fc[CO-Gly-Ile-CSA]2 discrete cyclic supramolecular assemblies were formed in which the individual molecules assemble along the rims of the molecules, resulting in the formation of tubular peptide superstructures that possess a central cavity and are filled with water molecules. <p>b) Prior to my work, work by Hirao and Metzler-Nolte clearly showed that the two podand peptide chains in Fc-peptide conjugates are pointing away from each other. This would indicate that extended â-sheets cannot be formed by simply extending the podand peptide chains. In my work, I clearly demonstrate that, in contrast to earlier results, it is possible to use the Fc scaffold to stabilize â-sheet-like interactions in longer peptide chains. Two systems are described in this thesis Fc[CO-Gly-Val-Cys(Bz)-OMe]2 and Fc[CO-Gly-Ile-Cys(Bz)-OMe]2. In both the cases, amino acids are employed that have a high propensity for â-sheet formation. Both Fc-peptide conjugates exhibit strong interstrand hydrogen bonding, resembling that found in â-sheets.<p>c) In this work, I have demonstrated the use of ferrocene amino acid (Fca) to control the structure in peptides. In contrast to previous work by Metzler-Nolte, my work is largely focusing on the design of a repetitive Fca-peptide motif. It is proposed that this repetition will enable strong interactions between the peptide portions of the conjugate, resulting in the formation of an extended structure. To this effect, a series of Fca-conjugates of the type Boc-[Fca-Ala]n-OMe (n = 1-4) was synthesized and fully characterized. All systems display the expected interaction between the Ala residues having a 12-membered hydrogen bonded ring. Such a structural motif resembles that found in naturally occurring â-helical structures of the spike-region of some viral proteins. <p>d) I have also demonstrated the use of a novel Fc-derivative, Fc[NH-Boc]2, to control the structure of podand amino acid chains. Fc-diamine was synthesized by the convenient carbazide route giving this useful scaffold in high yield. This material was converted into its peptide conjugate and the resulting conjugate displays the elusive 14-membered hydrogen bonding ring. <p>Thus, in my work, I have provided a new complementary tool for peptide design that will undoubtedly find applications for the design of de novo proteins in the near future.
|
10 |
noneChien, Hui-Chueh 25 June 2010 (has links)
For business to develop overseas, product research and development, capital and human resources are important elements, but how to design appropriate to the overseas organization of resources and effective integration, to reach overseas business development objectives can not be ignored.Business growth process is traced and can be a phased, can identify current stage of business In this study, would like to understand the operation of the design for evolution multinational organization.
This study is used depth interviews to research; total selected four professional managers of multinational corporations. The research is show as below:
1.The actual operation of the board of multinational enterprises is still very much under the influence of shareholders holding the largest, but the foreign domestic corporate governance is more than good thinking.
2.Business department operates the impact of products and services will be taken to a large contingent suitable model, which patent is an important factor.
3.Evolution of organizational structure will be organized products have different impact on the operation of the specific thinking.
4.To control Organization will be the largest operation of restricted stock.
5.The ability to respond to environmental markets and will be types of overseas subsidiaries due to the impact of ownership concentration.
6.For the current situation of organization and future prospects of satisfaction will be affected by company history and the impact of leadership style.
|
Page generated in 0.0619 seconds