883 resultados para Computer-Aided Engineering and Design


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The development of a combined engineering and statistical Artificial Neural Network model of UK domestic appliance load profiles is presented. The model uses diary-style appliance use data and a survey questionnaire collected from 51 suburban households and 46 rural households during the summer of 2010 and2011 respectively. It also incorporates measured energy data and is sensitive to socioeconomic, physical dwelling and temperature variables. A prototype model is constructed in MATLAB using a two layer feed forward network with back propagation training which has a 12:10:24 architecture. Model outputs include appliance load profiles which can be applied to the fields of energy planning (microrenewables and smart grids), building simulation tools and energy policy.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This report describes the analysis and development of novel tools for the global optimisation of relevant mission design problems. A taxonomy was created for mission design problems, and an empirical analysis of their optimisational complexity performed - it was demonstrated that the use of global optimisation was necessary on most classes and informed the selection of appropriate global algorithms. The selected algorithms were then applied to the di®erent problem classes: Di®erential Evolution was found to be the most e±cient. Considering the speci¯c problem of multiple gravity assist trajectory design, a search space pruning algorithm was developed that displays both polynomial time and space complexity. Empirically, this was shown to typically achieve search space reductions of greater than six orders of magnitude, thus reducing signi¯cantly the complexity of the subsequent optimisation. The algorithm was fully implemented in a software package that allows simple visualisation of high-dimensional search spaces, and e®ective optimisation over the reduced search bounds.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The idea of a community of practice (CoP) has been offered as the engine to unlock the potential of organizational resources, mainly knowledge and people, to achieve the strategic goal of sustained competitiveness. The relevance and application of CoPs in large UK contracting companies was investigated using two case studies. Contrasting variations in the understanding of the concept between the two contracting companies were observed. While a CoP was applied in one company with strategic intent, the concept was not fully understood in the other. In one company, only a third of CoP members surveyed agreed that CoPs were a vehicle for driving best practice and innovation throughout the business; this compared with more than 60% in agreement in the other contracting firm. The higher agreement and satisfaction of CoP members in the latter case study was the result of the management's understanding and commitment. CoPs require time and organizational support to mature. The strategic inception and management support of CoP application is vital for their maturation and progress. Although the construction industry change discourses portray CoPs as fostering an environment of trust, and hence serving as innovation and competiveness enablers, their potential contribution to contracting firms does not provide a compelling case and hence merits further research studies.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Theorem-proving is a one-player game. The history of computer programs being the players goes back to 1956 and the ‘LT’ LOGIC THEORY MACHINE of Newell, Shaw and Simon. In game-playing terms, the ‘initial position’ is the core set of axioms chosen for the particular logic and the ‘moves’ are the rules of inference. Now, the Univalent Foundations Program at IAS Princeton and the resulting ‘HoTT’ book on Homotopy Type Theory have demonstrated the success of a new kind of experimental mathematics using computer theorem proving.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper explores the mapping of the environmental assessment process onto design and construction processes. A comparative case study method is used to identify and account for variations in the ‘fit’ between these two processes. The analysis compares eight BREEAM projects (although relevant to LEED, GreenStar, etc.) and distinguishes project-level characteristics and dynamics. Drawing on insights from literature on sustainable construction and assessment methods, an analytic framework is developed to examine the effect of clusters of project and assessment level elements on different types of fit (tight, punctual and bolt-on). Key elements distinguishing between types include: prior working experience with project team members, individual commitment to sustainable construction, experience with sustainable construction, project continuity, project-level ownership of the assessment process, and the nature and continuity of assessor involvement. Professionals with ‘sustainable’ experience used BREEAM judiciously to support their designs (along with other frameworks), but less committed professionals tended to treat it purely as an assessment method. More attention needs to be paid to individual levels of engagement with, and understanding of, sustainability in general (rather than knowledge of technical solutions to individual credits), to ownership of the assessment process and to the potential effect of discontinuities at the project level on sustainable design.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The revolutions of electronic and mobile commerce have opened up unique opportunities for global marketing and business to consumer (B2C) persuasive interaction; with the aim of influencing user behavior. The success or failure of such persuasive interaction is impacted by cultural, social, and personal dimensions. Accordingly, failure to consider such dimensions risks the user forming a negative attitude towards retailer’s websites or mobile applications, which subsequently threatens customer behavior. A better understanding of human factors influencing the way people perceive B2C persuasive interaction is needed. This paper is introduces the concept of a context relevant persuasive interaction and proposes a guideline for designing relevant B2C persuasive interaction.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The rapid development of data transfer through internet made it easier to send the data accurate and faster to the destination. There are many transmission media to transfer the data to destination like e-mails; at the same time it is may be easier to modify and misuse the valuable information through hacking. So, in order to transfer the data securely to the destination without any modifications, there are many approaches like cryptography and steganography. This paper deals with the image steganography as well as with the different security issues, general overview of cryptography, steganography and digital watermarking approaches.  The problem of copyright violation of multimedia data has increased due to the enormous growth of computer networks that provides fast and error free transmission of any unauthorized duplicate and possibly manipulated copy of multimedia information. In order to be effective for copyright protection, digital watermark must be robust which are difficult to remove from the object in which they are embedded despite a variety of possible attacks. The message to be send safe and secure, we use watermarking. We use invisible watermarking to embed the message using LSB (Least Significant Bit) steganographic technique. The standard LSB technique embed the message in every pixel, but my contribution for this proposed watermarking, works with the hint for embedding the message only on the image edges alone. If the hacker knows that the system uses LSB technique also, it cannot decrypt correct message. To make my system robust and secure, we added cryptography algorithm as Vigenere square. Whereas the message is transmitted in cipher text and its added advantage to the proposed system. The standard Vigenere square algorithm works with either lower case or upper case. The proposed cryptography algorithm is Vigenere square with extension of numbers also. We can keep the crypto key with combination of characters and numbers. So by using these modifications and updating in this existing algorithm and combination of cryptography and steganography method we develop a secure and strong watermarking method. Performance of this watermarking scheme has been analyzed by evaluating the robustness of the algorithm with PSNR (Peak Signal to Noise Ratio) and MSE (Mean Square Error) against the quality of the image for large amount of data. While coming to see results of the proposed encryption, higher value of 89dB of PSNR with small value of MSE is 0.0017. Then it seems the proposed watermarking system is secure and robust for hiding secure information in any digital system, because this system collect the properties of both steganography and cryptography sciences.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Platelet-derived growth factor-BB (PDGF-BB) stimulates repair of healing-impaired chronic wounds such as diabetic ulcers and periodontal lesions. However, limitations in predictability of tissue regeneration occur due, in part, to transient growth factor bioavailability in vivo. Here, we report that gene delivery of PDGF-B stimulates repair of oral implant extraction socket defects. Alveolar ridge defects were created in rats and were treated at the time of titanium implant installation with a collagen matrix containing an adenoviral (Ad) vector encoding PDGF-B (5.5 x 10(8) or 5.5 x 10(9) pfu ml (1)), Ad encoding luciferase (Ad-Luc; 5.5 x 10(9) pfu ml (1); control) or recombinant human PDGF-BB protein (rhPDGF-BB, 0.3 mg ml (1)). Bone repair and osseointegration were measured through backscattered scanning electron microscopy, histomorphometry, microcomputed tomography and biomechanical assessments. Furthermore, a panel of local and systemic safety assessments was performed. Results indicated that bone repair was accelerated by Ad-PDGF-B and rhPDGF-BB delivery compared with Ad-Luc, with the high dose of Ad-PDGF-B more effective than the low dose. No significant dissemination of the vector construct or alteration of systemic parameters was noted. In summary, gene delivery of Ad-PDGF-B shows regenerative and safety capabilities for bone tissue engineering and osseointegration in alveolar bone defects comparable with rhPDGF-BB protein delivery in vivo. Gene Therapy (2010) 17, 95-104; doi: 10.1038/gt.2009.117; published online 10 September 2009

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The understanding of electrostatic interactions is an essential aspect of the complex correlation between structure and function of biological macromolecules. It is also important in protein engineering and design. Theoretical studies of such interactions are predominantly done within the framework of Debye-Huckel theory. A classical example is the Tanford-Kirkwood (TK) model. Besides other limitations, this model assumes an infinitesimally small macromolecule concentration. By comparison to Monte Carlo (MC) simulations, it is shown that TK predictions for the shifts in ion binding constants upon addition of salt become less reliable even at moderately macromolecular concentrations. A simple modification based on colloidal literature is suggested to the TK scheme. The modified TK models suggested here satisfactorily predict MC and experimental shifts in the calcium binding constant as a function of protein concentration for the calbindin D-9k mutant and calmodulin.