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Kolada, Eric J. "Nest site selection and nest success of greater sage-grouse in Mono County, California." abstract and full text PDF (free order & download UNR users only), 2007. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1447600.
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Richardson, Thomas Willoughby. "Avian use, nest-site selection, and nesting success in Sierra Nevada aspen." abstract and full text PDF (free order & download UNR users only), 2007. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3275836.
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Bécot, Lorry. "Sélectionner des poules pondeuses adaptées à des systèmes d'élevage alternatifs à la cage." Electronic Thesis or Diss., Rennes, Agrocampus Ouest, 2023. http://www.theses.fr/2023NSARC165.
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L’élevage des poules pondeuses en cage disparaît en Europe, au profit de systèmes alternatifs qui offrent des conditions de vie plus respectueuses du bien-être des animaux. Les poules y évoluent en groupe et ont accès à des nids pour pondre. Or, les poules pondeuses sont traditionnellement issues de programmes de sélection reposant sur une mesure de la ponte en cage. La mise au point de nids électroniques enregistrant en continu la ponte au nid, offre l’opportunité de faire évoluer les programmes de sélection en élevant les lignées pures en groupe et au sol.Le premier objectif de cette thèse était de caractériser la ponte au nid et d’étudier le déterminisme génétique de potentiels critères de sélection pour l’améliorer. Le deuxième objectif était d’évaluer les niveaux d’interaction génotype-environnement, entre élevages au sol et en cage, pour les critères de qualité des œufs et de poids des poules.Enfin, une réorganisation des programmes de sélection avec un abandon des cages a été envisagée.La ponte au nid a été étudiée à travers 14 nouveaux caractères liés à la ponte, au rythme de ponte, au choix du nid, au temps passé dans le nid et au comportement social. Les héritabilités estimées pour ces caractères étaient moyennes à fortes et les corrélations génétiques faibles avec les critères de qualité des œufs et de poids des poules. Les interactions génotype-environnement se sont révélées limitées. Ces résultats confirment la possibilité de sélectionner des poules sur la ponte sans avoir recours à un phénotypage en cageCage rearing systems of laying hens is disappearing in Europe, in favour of cage-free systems that offer living conditions more respectful of the animals’ welfare. Hens live in groups and have access to nests for the egg-laying. Usually, laying hens have been bred in breeding programmes based on a measurement of the egg-laying in cages. The development of electronic nests that continuously record egg-laying in the nests offers the opportunity to change breeding programmes by raising pure lines in groups and on the floor.The first objective of this thesis was to characterize the egg-laying in nests and to study the genetic determinism of potential selection criteria to improve it. The second objective was to estimate the effects of genotype-by-environment interactions between floor and cage systems, for egg quality and body weight.The third and last objective was to explore a reorganisation of breeding programmes assuming the end of the use of cages.The egg-laying in nests was studied through 14 new traits related to egg-laying, laying rhythm, nest preference, time spent in the nest, and social behaviour. Heritability estimates for these traits were moderate-to-high and genetic correlations were low with egg quality and body weight. Genotype-by environment interactions were found to be limited. These results confirm the opportunity of selecting hens on egg-laying without the use of cages
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Cleland, Todd Andrew 1961. "Printed electronics : the next inkjet revolution." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/16986.
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Thesis (S.M.M.O.T.)--Massachusetts Institute of Technology, Sloan School of Management, Management of Technology Program, 2003.Includes bibliographical references.
Inkjet printing has proven to be a remarkable disruptive technology. From its humble beginnings in 1984 it has grown to become the dominant technology for personal computer-based printing. However, after almost two decades of strong growth, the Inkjet printing market is maturing. Companies large and small are now beginning to explore use of inkjet in a diverse range of new applications ranging from manufacture of next generation flat panel displays and low cost circuits to generation of biochips and fast-prototyping of 3-D objects. These new applications present existing inkjet players with exciting opportunities to leverage their knowledge and assets to exploit these new markets. This thesis explores the opportunities for inkjet technology in two emerging industries: 1) next-generation flat panel displays based on organic light-emitting diodes and 2) low cost, disposable circuits required for products such as radio-frequency identification tags and smart cards. These are likely to be the two biggest opportunities for non-traditional applications of inkjet technology. In both cases, inkjet provides a flexible, low cost manufacturing method that is a very compelling alternative to the expensive wafer fab processing required to produce today's flat panel displays and circuits. Each of these industries is analyzed in considerable depth to provide context for assessing the disruptive potential of inkjet. The potential of inkjet to become an important enabling technology is then analyzed using ideas and frameworks from the management ofteclmology literature. Both organic LED displays and low cost circuits appear likely to become disruptive technologies. The best early opportunity for non-traditional application of inkjet technology appears to be in display manufacturing. Here the technology fit with Inkjet capabilities is good and the strength of competing manufacturing technologies is relatively weak. Establishment of inkjet as an important production method for low cost circuits appears more challenging. The technology fit is not as good and competing low-cost technologies are further along in their development. It is recommended that existing inkjet players first address the display opportunity to gain experience with transitioning inkjet from a consumer printing technology to one well suited to high-volume electronics manufacturing. Once this capability has been demonstrated the bigger challenges in circuit manufacturing can be addressed.
by Todd A. Cleland.
S.M.M.O.T.
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Azizi, Fazel Ahmad. "Advanced Electronic Signature." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for telematikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-14134.
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DiFi, Altinn and Lånekassen will implement a national digital signature to sign document submissions and mutual agreements. It is anticipated that a pilot will be launched in 2012.A digital signature is very different to a hand signature, for instance how to establish what you actually sign. Moreover, the verification of a digital signature requires a correct and valid public key, whereas a handwritten signature is physically produced by a person.The candidate of this project will try to understand the signature applications of Altinn and Lånekassen, then analyze the proposed digital signature architecture and standards to be used in the DiFi pilot and assess the utility and security of this solution compared to the existing Altinn "login signature".Furthermore, the candidate will try to identify one or more parts of the architecture that can be given an alternative solution, and state the arguments that support that this will be an improvement. If time allows, experimental results in software that support the claims may be carried out.
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Sarat, Austin. "Interdisciplinary legal studies [electronic resource] : the next generation." Thesis, Bingley, UK : Emerald, 2010. http://hdl.handle.net/10945/7827.
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Approved for public release; distribution is unlimited"Hybrid" justice at the Special Court for Sierra Leone / Sara Kendall -- Surviving property : resistance against urban housing nationalization during the transformation to communism (Romania, 1950-1965) / Mihaela Serban Rosen -- Disciplinary evolution of Turkish prisons, 1980s-1990s / Arda Ibikoglu -- "I'm Gonna Call My Lawyer" : shifting legal consciousness at the intersection of inequality / Diana Hern©Øandez -- A more global court? : a call for a new perspective on judicial globalization and its effect on the U.S. Supreme Court / Angela Narasimhan -- The sovereign city? : negotiating self-determination in an American military enclave / Erin E. Fitz-Henry -- Technique and technology in the kitchen : comparing resistance to municipal trans fat and foie gras bans / Michaela DeSoucey and David Schleifer -- Indigeneity : before and beyond the law / Kathleen Birrell
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Velardo, Amalia. "Small organic molecules for next generation electronics." Doctoral thesis, Universita degli studi di Salerno, 2016. http://hdl.handle.net/10556/2215.
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2014 - 2015In this PhD thesis attention has been focused on the theoretical design of organic small molecules for next generation electronics. The task of this thesis has concerned with the theoretical analysis of the operational performances of small dyes in photovoltaic solar cells, both in bulkheterojunction and dye sensitized solar cells; with particular emphasis on the theoretical analysis of the rates of the elementary electron transfer processes. A full quantum mechanics procedure for computing the rates of elementary electron transfer processes has been developed. The procedure starts from the Fermi Golden Rule (FGR) expression of the rate of electronic transitions and makes use of a rigorous evaluation of the Franck-Condon weighted density of states, performed by Kubo’s generating function approach. The analysis of electron transfer rates has revealed to be a very powerful tool for investigating structure-property relationships for the employment of small organic molecules in photovoltaic solar cells. The methodology has been applied to a class of small organic molecules, which show different power energy conversion efficiencies. The different efficiencies of the dyes have been attributed to very different rates of photoinduced electron transfer, the first step of energy conversion process in any type of photovoltaic solar cell. The last part of this thesis has been devoted to a very important task for next generation electronics: the rational design of new N-rich fused-ring heteroaromatics small organic molecules for n-type charge transport in thin layers. The substitution of CH units with nitrogen atoms is particularly appealing because, it offers the possibility of tuning the electron donor/acceptor character of the molecule. [edited by author]
XIV n.s.
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Douillet, Alban. "A compiler framework for loop nest software-pipelining." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 5.98 Mb., p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3220641.
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Stenbro, Martine. "A Survey of Modern Electronic Voting Technologies." Thesis, Norwegian University of Science and Technology, Department of Telematics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-10906.
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The last decade, electronic voting has evolved from being a mean of counting votes to also offer the possibility of electronically casting votes. From recording votes using punch cards and optical scan systems, electronic voting has evolved into the use of direct-recording-electronic machines. Voting over the Internet has also become a hot research topic, and some implementation and testing have been done. Internet voting systems are significantly more vulnerable to threats from external attackers, than systems to cast ballots in controlled environments. Mechanisms to provide security, accuracy and verification are critical, and issues with coercion and usability also arise.In the first part of this thesis we give a theoretical study about existing electronic voting techniques, as well as requirements and security issues of modern electronic voting systems. We also give a brief background theory of some cryptographic mechanisms and systems. Secondly, we present two modern voting solutions in development. We have included security functionalities provided by the system, the cryptographic techniques used and some threats and attacks to the systems. These systems can be exposed to compromised computers, ballot stuffing, and corrupt infrastructure players, but are using cryptographic proofs to ensure accuracy and counter attacks.In the third part, we create a procedure and perform a usability test on one of these modern voting solutions. Our findings emphasize the fact that there is a tension between verifiable elections and usability. The voters have trust in the privacy and accuracy of such a voting systems if more guidance to utilize the means of verification is included, and a trusted third party verifies the system security. The advantages of electronic voting outweigh the risks. Internet voting is a term of further discussion and testing, but considering coercion and the insecure aspects of the medium, Internet voting will never be 100% safe. It is a question of trade off between the advantages and threats.
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Goodman, David. "Open Access: What Comes Next." Association of Learned and Professional Society Publishers, 2005. http://hdl.handle.net/10150/105958.
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Please see the revised version
"Open Access: What Comes Next After 2004"
(also in this archive)This article examines the effects that present decisions about open access (OA) will have over the next ten years. It will be shown that the consequences are affected both by deliberate choices of policy by librarians and publishers, as well as by the adoption of various alternatives by scientific authors. The eventual result could be excellent, or quite otherwise.
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Watanabe, Aruto. "Analysis of Crystal and Electronic Structures of Next Generation Cathode Materials." Kyoto University, 2020. http://hdl.handle.net/2433/253385.
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Kyoto University (京都大学)0048
新制・課程博士
博士(人間・環境学)
甲第22549号
人博第952号
新制||人||226(附属図書館)
2019||人博||952(吉田南総合図書館)
京都大学大学院人間・環境学研究科相関環境学専攻
(主査)教授 内本 喜晴, 教授 吉田 寿雄, 准教授 戸﨑 充男
学位規則第4条第1項該当
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Ahmed, Iffat. "Multimedia quality improvements for next generation networks." Thesis, IMT Alti Studi Lucca, 2013. http://e-theses.imtlucca.it/115/1/Iffat_phdthesis.pdf.
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Video is foreseen to be dominant in the Internet and Next
Generation Networks, due to the increased usage of multimedia applications. The current Internet, and in particular the mobile Internet, was not designed with video requirements in mind and as a consequence, its architecture is very inefficient when handling video traffic. Not only is a policy optimization required, but it is also important to perform such an optimization in the proper manner. Therefore, providing Quality of Experience for such networks is an open issue and hot research area nowadays.
Our goal is to investigate the performance of the PHY/ Application cross-layer optimization, for which we developed
an analytical model to optimize the number of timeslots needed for a video to be correctly decoded with enhanced quality. The wireless channel is modeled by means of Markov chain, whose state represent different channel qualities. We exploit Crosslayer (PHY/ Application) solution with respect to application layer information about scalable video layers, and taking user channel status for adapting channel rates. This problem gets more crucial when the case of multicast is considered, as the base station needs to harmonize the heterogeneous requirements
of all the users and adapt transmission accordingly.
Performance is evaluated for various scenarios to investigate,
what is the optimum number of time slots needed for the base
layer of SVC, how does the feedback impacts on the end user
perceived quality and user satisfaction level, and to what extend
is Cross-layer optimization beneficial. Further, we evaluated
how the unicast extends to multicast and its impact on
end-user goodput, packet delivery delay and quality.
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Jeon, Hyung Min. "Multifunctional Oxide Heterostructures For Next-Generation Tunable RF/Microwave Electronics." Wright State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=wright1578950463103112.
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Pezaros, D. "Network traffic measurement for the next generation Internet." Thesis, Lancaster University, 2005. http://eprints.lancs.ac.uk/12698/.
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Measurement-based performance evaluation of network traffic is a fundamental prerequisite for the provisioning of managed and controlled services in short timescales, as well as for enabling the accountability of network resources. The steady introduction and deployment of the Internet Protocol Next Generation (IPNG-IPv6) promises a network address space that can accommodate any device capable of generating a digital heart-beat. Under such a ubiquitous communication environment, Internet traffic measurement becomes of particular importance, especially for the assured provisioning of differentiated levels of service quality to the different application flows. The non-identical response of flows to the different types of network-imposed performance degradation and the foreseeable expansion of networked devices raise the need for ubiquitous measurement mechanisms that can be equally applicable to different applications and transports. This thesis introduces a new measurement technique that exploits native features of IPv6 to become an integral part of the Internet's operation, and to provide intrinsic support for performance measurements at the universally-present network layer. IPv6 Extension Headers have been used to carry both the triggers that invoke the measurement activity and the instantaneous measurement indicators in-line with the payload data itself, providing a high level of confidence that the behaviour of the real user traffic flows is observed. The in-line measurements mechanism has been critically compared and contrasted to existing measurement techniques, and its design and a software-based prototype implementation have been documented. The developed system has been used to provisionally evaluate numerous performance properties of a diverse set of application flows, over different-capacity IPv6 experimental configurations. Through experimentation and theoretical argumentation, it has been shown that IPv6-based, in-line measurements can form the basis for accurate and low-overhead performance assessment of network traffic flows in short time-scales, by being dynamically deployed where and when required in a multi-service Internet environment.
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Papakonstantinou, Athanasios. "Mechanism design for eliciting costly observations in next generation citizen sensor networks." Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/143535/.
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Citizen sensor networks are open information systems in which members of the public act as information providers. The information distributed in such networks ranges from observations of events (e.g. noise measurements or monitoring of environmental parameters) to probabilistic estimates (e.g. projected traffic reports or weather forecasts). However, due to rapid advances in technology such as high speed mobile internet and sophisticated portable devices (from smart-phones to hand-held game consoles), it is expected that citizen sensor networks will evolve. This evolution will be driven by an increase in the number of information providers, since, in the future, it will be much easier to gather and communicate information at a large scale, which in turn, will trigger a transition to more commercial applications. Given this projected evolution, one key difference between future citizen sensor networks and conventional present ones is the emergence of self-interested behaviour, which can manifest in two main ways. First, information providers may choose to commit insufficient resources when producing their observations, and second, they may opt to misreport them. Both aspects of this self-interested behaviour are ignored in current citizen sensor networks. However, as their applications are broadened and commercial applications expand, information providers are likely to demand some kind of payment (e.g. real or virtual currency) for the information they provide. Naturally, those interested in buying this information, will also require guarantees of its quality. It is these issues that we deal with in this thesis through the introduction of a series of novel two-stage mechanisms, based on strictly proper scoring rules. We focus on strictly proper scoring rules, as they have been used in the past as a method of eliciting truthful reporting of predictions in various forecasting scenarios (most notably in weather forecasting). By using payments that are based on such scoring rules, our mechanisms effectively address the issue of selfish behaviour by motivating information providers in a citizen sensor network to, first, invest the resources required by the information buyer in the generation of their observations, and second, to report them truthfully. To begin with, we introduce a mechanism that allows the centre (acting as an information buyer) to select a single agent that can provide a costly observation at a minimum cost. This is the first time a mechanism has been derived for a setting in which the centre has no knowledge of the actual costs involved in the generation of the agents' observations. Building on this, we then make two further contributions to the state of the art, with the introduction of two extensions of this mechanism. First, we extend the mechanism so that it can be applied in a citizen sensor network where the information providers do not have the same resources available for the generation of their observations. These different capabilities are reflected in the quality of the provided observations. Hence, the centre must select multiple agents by eliciting their costs and the maximum precisions of their observations and then ask them to produce these observations. Second, we consider a setting where the information buyer cannot gain any knowledge of the actual outcome beyond what it receives through the agents' reports. Now, because the centre is not able to evaluate the providers' reported observations through external means, it has to rely solely on the reports it receives. It does this by fusing the reports together into one observation which then uses as a means to assess the reports of each of the providers. For the initial mechanism and each of the two extensions, we prove their economic properties (i.e. incentive compatibility and individual rationality) and then present empirical results comparing a number of specific scoring rules, which includes the quadratic, spherical, logarithmic and a parametric family of scoring rules. These results show that although the logarithmic scoring rule minimises the mean and variance of an agent's payment, using it may result in unbounded payments if an agent provides an observation of poor quality. Conversely, the payments of the parametric family exhibit finite bounds and are similar to those of the logarithmic rule for specific values of the parameter. Thus, we show that the parametric scoring rule is the best candidate in our setting. We empirically evaluate both extended mechanisms in the same way, and for the first extension, we show that the mechanism describes a family of possible ways to perform the agent selection, and that there is one that dominates all others. Finally, we compare both extensions with the peer prediction mechanism introduced by \cite{trustsr1} and show that in all three mechanisms the total expected payment is the same, while for both our mechanisms the variance in the total payment is significantly lower.
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Romeo, Lorenzo. "Semiconductor nanowires: the building block for next generation electronics and photonics." Doctoral thesis, Scuola Normale Superiore, 2016. http://hdl.handle.net/11384/86200.
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Hurtig, Patrik. "On Routing Two-Point Nets Across a Three-Dimensional Channel." Thesis, Linköping University, Department of Electrical Engineering, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2948.
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Routing techniques for plain ’flat’ microchips have been developed extensively and will soon reach its limitations. One natural step would be to develop chips which are manufactured in a more cubic type of volume, as oppose to the classical flat design.
This thesis proposes a method for routing two-point nets across a three- dimensional channel. The height required by this algorithm is of the order O(n (3/2)), where n is the number of terminals on a square top-layer with the side 2 (n(1/2)).
The algorithm proposed here is based on"On Routing Two-Point Nets Across a Channel", by Ron Y. Pinter [9], and the concepts from this paper are explainedin this thesis to familiarise the reader these.
It is also shown that the proposed algorithm is more effective in its volume than the two-dimensional counterpart. The algorithm here is of the order O(n(3/2)) with the two-dimensional algorithm of the order O(n2).
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Finney, Joseph. "Supporting continuous multimedia services in next generation mobile systems." Thesis, Lancaster University, 1999. http://eprints.lancs.ac.uk/11685/.
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Hassan, Ali. "Particle swarm optimization for routing and wavelength assignment in next generation WDM networks." Thesis, Queen Mary, University of London, 2010. http://qmro.qmul.ac.uk/xmlui/handle/123456789/533.
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All-optical Wave Division Multiplexed (WDM) networking is a promising technology for long-haul backbone and large metropolitan optical networks in order to meet the non-diminishing bandwidth demands of future applications and services. Examples could include archival and recovery of data to/from Storage Area Networks (i.e. for banks), High bandwidth medical imaging (for remote operations), High Definition (HD) digital broadcast and streaming over the Internet, distributed orchestrated computing, and peak-demand short-term connectivity for Access Network providers and wireless network operators for backhaul surges. One desirable feature is fast and automatic provisioning. Connection (lightpath) provisioning in optically switched networks requires both route computation and a single wavelength to be assigned for the lightpath. This is called Routing and Wavelength Assignment (RWA). RWA can be classified as static RWA and dynamic RWA. Static RWA is an NP-hard (non-polynomial time hard) optimisation task. Dynamic RWA is even more challenging as connection requests arrive dynamically, on-the-fly and have random connection holding times. Traditionally, global-optimum mathematical search schemes like integer linear programming and graph colouring are used to find an optimal solution for NP-hard problems. However such schemes become unusable for connection provisioning in a dynamic environment, due to the computational complexity and time required to undertake the search. To perform dynamic provisioning, different heuristic and stochastic techniques are used. Particle Swarm Optimisation (PSO) is a population-based global optimisation scheme that belongs to the class of evolutionary search algorithms and has successfully been used to solve many NP-hard optimisation problems in both static and dynamic environments. In this thesis, a novel PSO based scheme is proposed to solve the static RWA case, which can achieve optimal/near-optimal solution. In order to reduce the risk of premature convergence of the swarm and to avoid selecting local optima, a search scheme is proposed to solve the static RWA, based on the position of swarm‘s global best particle and personal best position of each particle. To solve dynamic RWA problem, a PSO based scheme is proposed which can provision a connection within a fraction of a second. This feature is crucial to provisioning services like bandwidth on demand connectivity. To improve the convergence speed of the swarm towards an optimal/near-optimal solution, a novel chaotic factor is introduced into the PSO algorithm, i.e. CPSO, which helps the swarm reach a relatively good solution in fewer iterations. Experimental results for PSO/CPSO based dynamic RWA algorithms show that the proposed schemes perform better compared to other evolutionary techniques like genetic algorithms, ant colony optimization. This is both in terms of quality of solution and computation time. The proposed schemes also show significant improvements in blocking probability performance compared to traditional dynamic RWA schemes like SP-FF and SP-MU algorithms.
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Dongxu, Yang. "Novel resists for next generation lithography." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6532/.
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With progress in the semiconductor industry, transistor density on a single computer chip has increased dramatically. This has resulted in a continuous shrinkage of the minimum feature size printed through microlithography technology. Resist, as the pattern recording medium of such printing, has been extensively studied to achieve higher resolution, higher sensitivity and lower line edge roughness. For decades this has been realized through chemical amplification. With the feature size continuously shrinking and the energy of exposure source therefore exceeding the resist ionization threshold, the performance of conventional chemically amplified resists is approaching the limits. Novel high-performance chemically amplified resists or non-chemically amplified resists are urgently needed to meet the requirement of next generation lithography. In this work a negative tone chemically amplified resist system based on a novel method to control the catalytic chain reaction is presented. The method to control the catalytic chain reaction is demonstrated using two model polymer resists. This method is then applied to a fullerene-based molecular resist system and a combination of good industrial compatibility, high resolution and good sensitivity has been achieved in this resist. Through a chromatographic separation, another chemically amplified molecular resist was also developed with further improved performance. An alternative route to sensitivity improvement other than chemical amplification is then introduced and a family of fullerene-based metal containing materials is presented. Lithographic performance is compared between the fullerene-metal resists and their control materials without metal. Using an aberration corrected scanning transmission electron microscope, the distribution of metal in the resist film and its behavior during the lithography process is evaluated and discussed.
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Culverhouse, Philip Frederick. "A specification for a next generation CAD toolkit for electronics product design." Thesis, University of Plymouth, 1993. http://hdl.handle.net/10026.1/2648.
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Electronic engineering product design is a complex process which has enjoyed an increasing provision of computer based tools since the early 1980's. Over this period computer aided design tool development has progressed at such a pace that new features and functions have tended to be market driven. As such CAD tools have not been developed through the recommended practise of defining a functional specification prior to any software code generation. This thesis defines a new functional specification for next generation CAD tools to support the electronics product design process. It is synthesized from a review of the use of computers in the electronics product design process, from a case study of Best Practices prevalent in a wide range of electronics companies and from a new model of the design process. The model and the best practices have given rise to a new concept for company engineering documentation, the Product Book which provides a logical framework for constraining CAD tools and their users (designers) as means of controlling costs in the design process. This specification differs from current perceptions of computer functionality in the CAD tool industry by addressing human needs together with company needs of computer supported design, rather than just providing more technological support for the designer in isolation.
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Cheng, Zhangkai Jason. "A next-generation electronic portal imaging device for simultaneous imaging and dosimetry in radiotherapy." Thesis, University of Sydney, 2020. https://hdl.handle.net/2123/23508.
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The aim of this thesis is to develop a next-generation Electronic Portal Imaging Device (EPID) for simultaneous megavoltage imaging and dosimetry in radiotherapy. The results of this thesis include the identification of a clinically implementable pixel sensitivity correction technique for a water equivalent EPID. This is important for clinical translation of this new technology. The imaging performance of an existing water equivalent EPID prototype previously developed by our group has been measured and characterised for the first time. The zero-frequency detective quantum efficiency (DQE) was found to be ~3%, which is a factor of three better than standard clinical EPIDs, which are not water-equivalent. A new design is proposed for further gains in imaging performance based on an array of air-clad optical fibres, and a fabrication method based on extrusion and fibre drawing has been developed and evaluated. Using finite element modelling simulations, a novel method is investigated for enhancing light output from the plastic scintillator array EPID. This method is based on inserting a nano-structured layer at the scintillator-detector interface, to maximize light transmission through the boundary. Overall, the work presented in this thesis demonstrates the feasibility of a next-generation EPID for clinical radiotherapy, with enhanced performance compared to standard clinical EPIDs.
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Raghunathan, Rajiv. "Virtual qualification methodology for next-generation area-array packages." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/18849.
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Wrzyszcz, Artur. "Employing Petri nets in digital design : an area and power minimization perspective." Thesis, University of Bristol, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.265361.
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Sato, Shinya. "Design and implementation of a low-level language for interaction nets." Thesis, University of Sussex, 2015. http://sro.sussex.ac.uk/id/eprint/54469/.
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Interaction nets are a graphical model of computation based on a restricted form of graph rewriting. A specific net can represent a program with a user-defined set of nodes and computation is modelled by a user-defined set of rewrite rules. This very simple model has had great success in modelling sharing in computation (specifically in the lambda calculus), and there is potential for generating a new theoretical foundation of parallel computation since all computation steps are local and thus can be implemented in parallel. This thesis is about the implementation of interaction nets. Specifically, for the first contributions we define a low-level language as an object language for the compilation of interaction nets. We study the efficiency and properties of different data structures, and focus on the management of the rewriting process which is usually hidden in the graph rewriting system. We provide experimental data comparing the different choices of data structures and select one for further development. For the compilation of nets and rules into this language, we show an optimisation such that allocated memory for agents is reused, and thus we obtain optimal efficiency for the rewriting process. The second part of this thesis describes extensions of interaction nets so that they can be used as a programming language. Interaction nets in their pure form are quite restrictive in expressive power. By extending the notions of agents and rules we can express computation more naturally, yet still preserve the good properties (such as strong confluence) of the rewriting system. We then implement a selection of algorithms using and extending the compilation techniques developed in the first part of the thesis. We also demonstrate experimental results on multi-core CPUs, using the Posix-thread library, thus realising some of the potential for parallel implementation mentioned above.
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Wang, Zhongnan. "Tribological investigation for next-generation polymeric micro-systems." Thesis, University of Warwick, 2016. http://wrap.warwick.ac.uk/91016/.
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The development of micro-fabrication processes for 3D microstructures has led to the production of low-cost, low-energy devices at millimeter scales known as MEMS for a wide range of electronic, mechanical, mechatronic and biomedical applications. As surface-to-volume ratio increases drastically with decreasing dimension, surface properties of the materials are the prominent factor at the interface between two solids and consequent tribological issues such as adhesion, friction and wear will arise in MEMS devices when surfaces are in, or have the potential for, sliding contact. Measurement techniques and principles used in micro-tribology are quite different from those in macro-tribology. Various specialized micro-tribometers have attracted recent attention in attempts to obtain consistent, accurate tribological measurements that could provide information for the design of MEMS components. However, even these have operational parameters quite different to those in the regime typical of MEMS devices. For example, the thermal properties of polymers might mean that they are especially sensitivity to the speeds and reciprocating scan frequencies of measurements. This is a serious concern because the selection of appropriate materials for such applications is very important in order to reduce not only friction and wear, but also the stiction of the parts. The immediate challenge is that there is very little reliable information about the properties of this new generation of engineering materials because of insufficient understanding and characterization of their behaviour at the microscale under a wide range of experimental conditions. With these points in mind, this thesis aims to prompt wide study of the micro-tribological properties of polymers for MEMS applications, providing preliminary new data on them while exploring in some detail possible uncertainty effects that could arise from the testing regimes of most micro-tribometers. It starts by re-commissioning and characterizing a unique, wide-bandwidth prototype micro-tribometer developed at Warwick, establishing good operating procedures by comparing measurements on materials widely discussed in the literature. New data has been collected on an acrylate resin typically used for micro-stereo-lithography, PTFE and oxide-coated silicon. It suggests that deviations from Amonton’s law in the ten millinewton range might be less severe than previously reported. Observing that the skill and time required for such testing makes it unattractive for a production control environment, the thesis then explores, via contact modelling, whether there is a useful correlation between Berkovich tip nano-hardness and the micro-friction of the polymeric samples: several plausible modelling assumptions are shown to lead to inconsistencies. Final discussions and recommendations consider how to move on from these experimental scoping studies to acquire detailed evaluations of the properties of the best candidates under typical usage conditions prior to designers of potential products taking these materials and processes at all seriously.
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Singh, Gurinder Jit. "Development of an E-commerce web application using .NET technology." [Chico, Calif. : California State University, Chico], 2009. http://hdl.handle.net/10211.4/103.
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Stephens, Owen. "Compositional specification and reachability checking of net systems." Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/385201/.
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Concurrent systems are frequently scrutinised using automated model checking, routinely using Petri nets as a model. While for small system models, it is often sufficient to give the system specification in a monolithic manner, for larger systems this approach is infeasible. Instead, a compositional, or component-wise specification can be used. However, while existing model checking techniques sometimes allow the specification of nets in terms of components, the techniques used for checking properties of the system all consider the composed, global net. In this thesis, we investigate and advocate compositional system specification and an alternative approach to model checking that uses the structural compositional information to its advantage, vastly improving efficiency in many examples. In particular, we examine the categorical structure of component nets and their semantics, illustrating the functoriality of a map between the categories as compositionality. We introduce contextual Petri Nets with Boundaries (PNBs), adding read arcs, which naturally model behaviour that non-destructively reads the token state of a place. Furthermore, we introduce a type-checked specification language that allows us to compositionally construct systems to be modelled using PNBs, whilst ensuring that only correct compositions are expressible. We then discuss and implement compositional statespace generation, which can be used to check reachability. Via optimisations using weak language equivalence and memoisation, we obtain substantial speed ups and demonstrate that our checker outperforms the current state-of-the-art for several examples. A final contribution is the compositional specification of existing benchmark examples, in more natural, component-wise style.
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York, Jr John Benson. "An Isolated Micro-Converter for Next-Generation Photovoltaic Infrastructure." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/19326.
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Photovoltaic (PV) systems are a rapidly growing segment in the renewable energy industry. Though they have humble origins and an uncertain future, the commercial viability of PV has significantly increased, especially in the past decade. In order to make PV useful, however, significant effort has to go into the power conditioning systems that take the low-voltage dc from the panel and create utility compatible ac output. Popular architectures for this process include the centralized inverter and the distributed micro-inverter, each with its own advantages and disadvantages. One attempt to retain the advantages of both architectures is to centralize the inverter function but construct PV panel-level micro-converters which optimize the panel output and condition the power for the inverter. The main focus of this work is to explore the technical challenges that face the evolution of the dc-dc micro-converter and to use them as a template for a vertically integrated design procedure. The individual chapters focus on different levels of the process: topology, modulation and control, transient mitigation, and steady-state optimization. Chapter 2 introduces a new dc-dc topology, the Integrated Boost Resonant (IBR) converter, born out of the natural design requirements for the micro-converter, such as high CEC efficiency, simple structure, and inherent Galvanic isolation. The circuit is a combination of a traditional PWM boost converter and a discontinuous conduction mode (DCM), series resonant circuit. The DCM operation of the high-frequency transformer possesses much lower circulating energy when compared to the traditional CCM behavior. When combined with zero-current-switching (ZCS) for the output diode, it results in a circuit with a high weighted efficiency of 96.8%. Chapter 3 improves upon that topology by adding an optimized modulation scheme to the control strategy. This improves the power stage efficiency at nominal input and enhances the available operating range. The new, hybrid-frequency method utilizes areas where the modulator operates in constant-on, constant-off, and fixed-frequency conditions depending on duty cycle, the resonant period length, and the desired input range. The method extends the operating range as wide as 12-48V and improves the CEC efficiency to 97.2% in the 250-W prototype. Chapter 4 considers the soft-start of the proposed system, which can have a very large capacitive load from the inverter. A new capacitor-transient limited (CTL) soft-start method senses the ac transient across the resonant capacitor, prematurely ending the lower switch on-time in order to prevent an excessive current spike. A prototype design is then applied to the IBR system, allowing safe system startup with a range of capacitive loads from 2μF to 500μF and a consistent peak current without the need for current sensing. Chapter 5 further investigates the impact of voltage ripple on the PV output power. A new method for analyzing the maximum power point tracking (MPPT) efficiency is proposed based on panel-derived models. From the panel model, an expression demonstrating the MPPT efficiency is derived, along with a ripple â "budgetâ " for the harmonic sources. These ripple sources are then analyzed and suggestions for controlling their contributions are proposed that enable circuit designers to make informed and cost-effective design decisions. Chapter 6 illustrates how results from a previous iteration can provide a basis for the next generation\'s design. A zero-voltage-switching (ZVS) version of the circuit in Chapter 2 is proposed, requiring only two additional MOSFETs and one inductor on the low-voltage side. The maximum switching frequency is then increased from 70kHz to 170kHz, allowing for a 46% reduction in converter volume (from 430cm3 to 230cm3) while retaining greater than 97% weighted efficiency.
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Chapagain, Kamal Raj. "Integration of Electronics and Mechanics in Next Generation Ultrasound Transducers in Medical Imaging." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elektronikk og telekommunikasjon, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-24325.
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Capacitive micromachined ultrasonic transducer (CMUT) has been emerging technology in the field of medical imaging after its first demonstration in early 90s. CMUTs are fabricated on silicon substrates using micromachining techniques. They can generate high frequencies due to the smaller dimensions feasible with microfabrication. CMUTs for immersion applications could be easily designed to provide fractional bandwidths exceeding 100%. Therefore, they are promising for applications like intravascular ultrasound (IVUS) where high resolution is required at short range. In this domain it may perform better than the existing piezoelectric ultrasound transducers. But there are certain issues that need to be taken care of before they can be used as commercial ultrasound transducers. One is echoes due to the acoustic wave propagation in the silicon substrate, and another is resonances caused by cross coupling between the neighboring elements in the CMUT arrays. In this thesis we investigate an acoustic backing structure that is to be added on the back side of the CMUT. The backing should absorb incident acoustic waves across a wide frequency band, and it must effectively suppress structural resonances and vibrations. To achieve this, the backing of a CMUT should have an acoustic impedance that matches with the silicon substrate, and it should be lossy. A good candidate for the backing is a tungsten filled epoxy. If the backing structure is thick enough, it will absorb the acoustic wave reflected back to the transducer and thus will remove any trailing echoes. In many cases the transducer is intended for applications where there is little room for a thick backing. Various approaches has been suggested to reduce the extra volume and weight added by a thick absorbing backing, one approach is to use a grooved backing structure. The grooves at the bottom of the backing provide an extra attenuation by scattering the waves in different directions so that a thinner backing would be sufficient. The scattering removes power from the specular reflection from the back surface which otherwise degrades the image quality. It has been shown that this type of structure reduces the specular reflection for a range of frequencies. When CMUTs are used in practical applications, the propagation of waves from a fluid medium into the backing or vice versa is blocked to some degree by total reflection, except for a range of steering angles around broadside. This is due to the difference in acoustic velocities of silicon and the fluid medium. This blocking is accompanied by the generation of surface waves in the silicon substrate, which also may impact the imaging and therefore must be controlled. In the present work we investigate the acoustic signal transmitted into the backing relative to the signal transmitted into the fluid medium when CMUT arrays on top of the silicon substrate are excited. This gives us an estimation of how much attenuation is needed from the acoustic backing layer. The purpose of the grooves on the backing structure is to provide an attenuation due to scattering which is in addition to the absorption loss in the epoxy tungsten composite. Experiments performed on the grooved backing structures show that such structures provide a satisfactory performance for the waves traveling normal to the bottom of the backing structure. But the acoustic waves propagating into the backing structure may not always be normal to the bottom of the structure. Therefore, the performance of the grooved backing structure is also studied for the waves traveling in oblique directions to the bottom surface of the backing. From our simulations we know that the performance of grooved structures for oblique incidence is not significantly different from that of normal incidence when the incident angle is within ±30◦ to the surface normal to the bottom of the structure. We have also shown that for a CMUT-backing stack immersed in a fluid medium, waves that reach into the backing from the fluid medium with significant power mostly lie within this range of angles. It means that a CMUT transducer with grooved backing structure always provide extra attenuation for the waves propagating into the substrates when it is used in practical applications. In this work we have also investigated acoustic properties of some polymers. The polymers, RTV 615 and Sylgard 160, have acoustic properties such that a thin layer of these polymers could be used to minimize the acoustic cross coupling in the CMUT arrays significantly. These materials could also be used as lens material for CMUT transducers together with stiff polymers such as TPX.
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Jouet, Simon. "Enhancing programmability for adaptive resource management in next generation data centre networks." Thesis, University of Glasgow, 2017. http://theses.gla.ac.uk/8535/.
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Recently, Data Centre (DC) infrastructures have been growing rapidly to support a wide range of emerging services, and provide the underlying connectivity and compute resources that facilitate the "*-as-a-Service" model. This has led to the deployment of a multitude of services multiplexed over few, very large-scale centralised infrastructures. In order to cope with the ebb and flow of users, services and traffic, infrastructures have been provisioned for peak-demand resulting in the average utilisation of resources to be low. This overprovisionning has been further motivated by the complexity in predicting traffic demands over diverse timescales and the stringent economic impact of outages. At the same time, the emergence of Software Defined Networking (SDN), is offering new means to monitor and manage the network infrastructure to address this underutilisation. This dissertation aims to show how measurement-based resource management can improve performance and resource utilisation by adaptively tuning the infrastructure to the changing operating conditions. To achieve this dynamicity, the infrastructure must be able to centrally monitor, notify and react based on the current operating state, from per-packet dynamics to longstanding traffic trends and topological changes. However, the management and orchestration abilities of current SDN realisations is too limiting and must evolve for next generation networks. The current focus has been on logically centralising the routing and forwarding decisions. However, in order to achieve the necessary fine-grained insight, the data plane of the individual device must be programmable to collect and disseminate the metrics of interest. The results of this work demonstrates that a logically centralised controller can dynamically collect and measure network operating metrics to subsequently compute and disseminate fine-tuned environment-specific settings. They show how this approach can prevent TCP throughput incast collapse and improve TCP performance by an order of magnitude for partition-aggregate traffic patterns. Futhermore, the paradigm is generalised to show the benefits for other services widely used in DCs such as, e.g, routing, telemetry, and security.
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Zhou, Zhenren. "Using predicate transition nets approach to verify the security of the secure electronic transaction protocol." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0008/MQ52382.pdf.
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Zhou, Zhenren Carleton University Dissertation Computer Science. "Using predicate transition nets approach to verify the security of the secure electronic transaction protocol." Ottawa, 2000.
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Rodríguez, Samaniego Javier. "Study and design of the front-end and readout electronics for the tracking plane in the NEXT experiment." Doctoral thesis, Universitat Politècnica de València, 2017. http://hdl.handle.net/10251/86285.
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The NEXT experiment is one of the most innovative ones looking for the neutrinoless double beta decay, which finding will answer one of the most important questions in the last years physics: is the neutrino its own antiparticle? Or in other words, is it a Majorana particle?
With that purpose NEXT uses a TPC (Time Projection Chamber) filled with enriched xenon gas at high pressure, and two photosensors planes, one on each end. The first plane contains PMTs (PhotoMultiplier Tube), that collect the light emitted by the xenon when an event happens and precisely measures its energy. The second plane is a SiPM (Silicon PhotoMultiplier) matrix that allows to 3D-reconstruct the event track. Both planes together allows NEXT to have a great background rejection, which makes a difference with the other experiments aiming for the neutrinoless double beta decay. In addition, SiPMs are a new technology which nowadays is evolving to, in the future, displace the classical PMTs. For that reason the study of these sensors starts from zero, as there were not previous uses as pixel-tracking, and lead a new path in the physics detectors, for both high and low energy.
This thesis is focused on the study and design of the electronics involving the tracking plane, which includes some technical solutions related also with mechanical issues. From the sensors placed inside the detector, the SiPMs, to the front-end electronic boards, there are few elements on the chain; as the support boards for the SiPMs which must satisfy severe outgassing and radiopurity levels. Also the inner and outer cabling has been designed, focusing on obtaining the best signal-noise ratio; and also the feedthrough for the tracking plane, which solved at low cost the huge problem of taking out about 4000 lines from the pressurized xenon to the outside.
Finally, one of the most important elements on this chain and the one that this thesis is focused on, is the front-end board. Starting with the experience acquired with the first prototype, NEXT-DEMO, the electronics have been improved, able to condition, integrate and digitize the signals from all the tracking plane SiPMs; allowing the further acquisition and processing through an ATCA-based system (Advanced Telecommunications Computing Architecture).
All the elements designed have been produced and assembled on the NEW detector, a large-scale prototype of the final detector, placed at the Laboratorio Subterra'neo de Canfranc, an underground laboratory at the aragonese Pyrenee.El experimento NEXT es uno de los más innovadores en la búsqueda de la desintegración doble beta sin neutrinos, cuyo hallazgo daría con la respuesta a una de las cuestiones más importantes de la física en los últimos años: ¿es el neutrino su propia antipartícula? O dicho de otro modo, ¿es una partícula de Majorana? Para ello NEXT hace uso de una TPC (Time Projection Chamber) llena de gas xenón enriquecido a alta presión, y con dos planos de fotosensores, uno en cada extremo. El primero de ellos está formado por PMTs (Photo Multiplier Tube), que recogen la luz generada por el xenón cuando ocurre un evento, y miden la energía de éste. El segundo consiste en una matriz de SiPMs (Silicon PhotoMultipliers) que permiten reconstruir tridimensionalmente la traza de dicho evento. El conjunto de ambos planos de fotosensores otorga al experimento NEXT un gran rechazo a eventos de fondo, lo que marca la diferencia con otros experimentos en busca de la desintegración doble beta sin neutrinos. Además, los SiPMs son una tecnoloía de reciente aparición que en la actualidad está evolucionando a grandes pasos para, en un futuro, desplazar a los fotomultiplicadores clásicos. Por ello el estudio de estos fotosensores parte prácticamente desde cero, ya que no existen aplicaciones previas de su uso como pixel-tracking, y ha permitido abrir un nuevo camino en los detectores de física, tanto de alta como baja energía. Esta tesis doctoral tiene como objetivo el estudio y diseño de la electrónica involucrada en el plano de reconstrucción de trazas, y que involucran en menor medida dar solución a problemas técnicos de aspecto mecánico. Partiendo de los sensores ubicados dentro del detector, los SiPMs, hasta las tarjetas de front-end, se incluyen varios elementos de la cadena; como son las tarjetas empleadas como soporte para los SiPM en el interior de la cámara, las cuáles deben cumplir rigurosas medidas de radiopureza y degasificación. También se ha diseñado el cableado tanto interno como externo, haciendo énfasis en conseguir la mayor relación posible señal-ruido; y el pasamuros específico para el plano de reconstrucción de trazas, el cual ha resuelto a bajo coste el problema de extraer casi 4000 líneas desde la zona de xenón a alta presión hasta el exterior. Por último, uno de los elementos más importantes de esta cadena y en el cuál se centra principalmente esta tesis, es la tarjeta de front-end. Partiendo de la experiencia adquirida del primer prototipo del experimento, NEXT-DEMO, se ha perfeccionado una electrónica capaz de tratar, integrar y adquirir las señales de todos los SiPM del plano de reconstrucción de trazas, permitiendo su posterior adquisición y procesado mediante un sistema basado en la estructura ATCA (Advanced Telecommunications Computing Architecture). Todos los elementos diseñados han sido ensamblados y puestos en marcha en el detector NEW, un prototipo a gran escala del detector final, que está ubicado en el Laboratorio Subterráneo de Canfranc, en el Pirineo Aragonés.
L'experiment NEXT és un dels més innovadors en la recerca de la desintegració doble beta sense neutrins, i aquesta troballa donaria amb la resposta a una de les quèstions més importants de la física en els últims anys: és el neutrí la seua pròpia antipartícula? O dit d'una altra manera, és una partícula de Majorana? Per açò NEXT fa ús d'una TPC (Time Projection Chamber) plena de gas xenó enriquit a alta presió, i amb dos plànols de fotosensors, un a cada extrem. El primer d'ells està format per PMTs (Photo Multiplier Tube), que arrepleguen la llum generada pel xenó quan ocorre un esdeveniment, i mesuren l'energía d'aquest. El segon consisteix en una matriu de SiPMs (Silicon PhotoMultipliers) que permeten reconstruir tridimensionalment la traça d'aquest esdeveniment. El conjunt de tots dos plànols de fotosensors atorga a l'experiment NEXT un gran rebuig a esdeveniments de fons, la qual cosa marca la diferència amb altres experiments a la recerca de la desintegració doble beta sense neutrins. A més, els SiPMs so'n una tecnología de recent aparició que en l'actualitat està evolucionant a grans passos per a, en un futur, desplaçar als fotomultiplicadors clàssics. Per això l'estudi d'aquests fotosensors part pràcticament des de zero, ja que no hi ha aplicacions prèvies del seu ús com a pixel-tracking, i ha permés obrir un nou camí en els detectors de física, tant d'alta com de baixa energia. Aquesta tesi doctoral té com a objectiu l'estudi i diseny de l'electrònica involucrada en el plànol de reconstrucció de traces, i que involucra en menor mesura donar solució a problemes tècnics d'aspecte mecànic. Partint dels sensors situats dins del detector, els SiPMs, fins a les targetes de front-end, s'inclouen diversos elements de la cadena; com són les targetes emprades com a suport per als SiPMs a l'interior de la càmera, les quals han de complir rigoroses mesures de radioactivitat i degasificació. També s'ha disenyat el cablejat tant intern com extern, fent èmfasi en aconseguir la major relació possible senyal-soroll; i el passamurs específic per al plànol de reconstrucció de traces, el qual ha resolt a baix cost el problema d'extraure quasi 4000 línies des de la zona de xenó a alta presió fins a l'exterior. Finalment, un dels elements més importants d'aquesta cadena i en el qual es centra principalment aquesta tesi, és la targeta de front-end. Partint de l'experiència adquirida del primer prototip de l'experiment, NEXT-DEMO, s'ha perfeccionat una electrònica capaç de tractar, integrar i adquirir les senyals de tots els SiPM del plànol de reconstrucció de traces, permetent la seua posterior adquisició i processament mitjançant un sistema basat en l'estructura ATCA (Advanced Telecommunications Computing Architecture). Tots els elements disenyats han sigut muntats i engegats en el detector NEW, un prototip a gran escala del detector final, que està situat en el Laboratorio Subterráneo de Canfranc, al Pirineu Aragonés.
Rodríguez Samaniego, J. (2017). Study and design of the front-end and readout electronics for the tracking plane in the NEXT experiment [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/86285
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Varghese, Thazhone Tijo. "Next Generation SDN Switches Using Programming Protocol-Independent Packet Processors." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254899.
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Over recent years, Software Defined Networking has enabled operators to control the network and realize new networking topologies. With increasing network traffic and protocol formats that aim at managing the traffic efficiently, the capabilities offered by Software Defined Networking alone are currently limited by the underlying fixed hardware infrastructure. The inflexibility involved in redesigning the hardware forces the bottom-up approach defined by switch vendors in describing the network and limits the capabilities offered to operators for further innovation. To meet the demands of ensuring a higher degree of flexibility to design, test and guarantee a faster time to market, the concept of Softly Defined Networks was introduced. The idea in addition to offering the conventional advantages of Software Defined Networking is based upon implementing a re-programmable data-plane. Field-Programmable Gate Arrays offered a higher degree of flexibility and capability to handle such designs. Programming Protocol-independent Packet Processors(P4) is a high-level language continuously evolving to define data-planes for various networking devices. The aim of P4 is for network operators to customize the underlying hardware with minimum constraints and ease, independent of the target. Therefore, the three major goals while defining such a language revolved around reconfigurability of hardware after being deployed, protocol independence to permit customization without constraints and target independence for users to be less concerned of the underlying hardware. Recent advances in P4 with the added support in terms of compatible targets and compilers have made P4 a viable opportunity to realize a re-programmable hardware. This work contributes towards exploring the ease of incorporating the capabilities of P4 in realizing a flexible data-plane. To achieve the same and study its characteristics a supporting two lane hardware pipeline is proposed that is capable of accommodating P4 upon a Kintex 7 FPGA. Primarily, a custom P4 module is defined that is capable of performing L2 operations upon a double tagged Ethernet frame using an appropriate architecture model. Subsequently, to integrate the P4 description on hardware the proposed supporting pipeline is implemented at a line rate of 10Gbps using the essential building blocks that help in observing the desired processing. Using a test setup, the design shall be further tested for the expected data-plane activity based upon the populated match-action rules. In terms of resource utilization, the overall design consumes less than 15% of the available resources and incurs an average latency of 5.71us. In addition to the ease of customization compared to the conventional fixed data-plane descriptions, it is vital to analyze the cost inherited while adopting P4. The final design is therefore studied in terms of resource utilization and latency by increasing the complexity of the P4 definition with regard to the number of headers, tables and write operations(H-T-W) for the adopted compiler. In the case of eight headers, tables and write operations(8H-8T-8W), there is an average latency of 8.01us and the P4 description alone demands 51536 LUTs, 77789 FFs and 118.5 BRAMs in terms of resource utilization. Finally, the article discusses the extent to which the proposed top-down approach is implemented and is capable of redefining the network as we know it.Under de senaste åren har Software Defined Networking gjort det möjligt för operatörer att styra nätverket och implementera nya nätverkstopologier. Med ökande nätverkstrafik och nya protokoll som syftar till att hantera trafiken effektivt, är de möjligheter som erbjuds av Software Defined Networking för närvarande begränsat av den underliggande fixa hårdvaruarkitekturen. Den inflexibla hårdvaran tvingar fram det ”bottom-up-” tillvägagångssätt som definieras av switchleverantörer när det gäller att beskriva nätverket och begränsar de möjligheter som erbjuds operatörerna för att styra och innovera i sina nät. För att möta kraven på att skapa en högre grad av flexibilitet för att designa, testa och garantera en snabbare tid till marknaden, introducerades begreppet Softly Defined Networks. Tanken, utöver att erbjuda de konventionella fördelarna med Software Defined Networking, bygger på att man implementerar ett omprogrammerbart dataplan. Field-Programmable Gate Arrays erbjuder en högre grad av flexibilitet och förmåga att hantera sådana konstruktioner. Programming Protocol-independent Packet Processors(P4) är ett språk på hög nivå som kontinuerligt utvecklas för att definiera dataplanet för olika nätverksenheter. Målet med P4 är att nätverksoperatörerna lätt ska kunna anpassa den underliggande hårdvaran med minimala begränsningar oberoende av leverantör av hårdvara. De tre huvudmålen när man definierade ett sådant språk handlade om omkonfigurerbarhet av hårdvaran efter att ha blivit utplacerad, protokolloberoende för att möjliggöra anpassning utan begränsningar och leverantörsoberoende för att användarna skulle vara mindre oroade över den underliggande hårdvaran. Nya framsteg i P4 när det gäller stöd för kompatibla hårdvaror och kompilatorer har gjort P4 till en tänkbar kandidat för att realisera en omprogrammerbar hårdvara. Detta arbete bidrar till att utforska hur enkelt det är att integrera P4:s förmåga att realisera ett flexibelt dataplan. För att uppnå detta och studera dess egenskaper föreslås en hårdvaruimplementation av L2 i två pipelines av P4 på en Kintex 7 FPGA. I första hand definieras en anpassad P4-modul som kan utföra L2-operationer på en dubbeltaggad Ethernet-ram med hjälp av en lämplig arkitekturmodell. Därefter implementeras P4-beskrivningen av hårdvaran på den föreslagna arkitekturmodellen med en hastighet av 10 Gbps med hjälp av de byggblock som krävs för att kunna observera beteendet. Med hjälp av en testupptällning testas konstruktionen för att se om den uppfyller den förväntade dataplanaktiviteten baserat på de uppsatta matchningsreglerna. När det gäller resursutnyttjandet förbrukar designen mindre än 15% av de tillgängliga resurserna och uppnår en genomsnittlig latens på 5,71us. Förutom den enkla implementeringen, jämfört med en konventionell fix beskrivning av data-planet, är det viktigt att analysera kostnaden vid införandet av P4. Den slutliga konstruktionen studeras därför med avseende på resursutnyttjande och latens genom att öka komplexiteten i P4-definitionen med avseende på antalet rubriker, tabeller och skrivoperationer (H-T-W) för den antagna kompilatorn. När det gäller åtta ”headers”, tabeller och skrivoperationer (8H-8T-8W), är det en genomsnittlig latens på 8.01us och P4-beskrivningen ensam kräver 51536 LUTs, 77789 FFs och 118,5 BRAMs vad gäller resursutnyttjande. Slutligen diskuterar artikeln hur den föreslagna top-down-metoden är implementerad och hur den kan omdefiniera nätverket som vi känner till det.
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Manyam, Jedsada. "Novel resist materials for next generation lithography." Thesis, University of Birmingham, 2011. http://etheses.bham.ac.uk//id/eprint/1333/.
Full textAbstract:
Fullerene derivatives have been demonstrated as negative-tone resists for electron beam lithography with impressive capability for high resolution and high plasma etching resistance, due to their carbon-rich nature. Their primary drawback of extremely poor sensitivity has been addressed by implementation of chemical amplification. A three-component chemically amplified negative-tone resist has been developed via the addition of a photoacid generator and a crosslinker to a fullerene derivative. This thesis work presents a significant extension of the previous work. The resists have undergone comprehensive optimisation, and systematic characterisation of electron beam lithography behaviours. In the first part, a systematic study into chemical amplification of negative-tone fullerene resists through variation of resist composition, additive, and resist processing in order to optimise sensitivity, resolution, line width roughness and etch resistance is presented. Sensitivity of sub 10 C/cm2 at 20 keV, half pitch resolution of 20 nm, a minimum sparse feature linewidth of 12 nm, line width roughness of sub 5 nm, and high etch resistance comparable with a commercial novolac resist have been demonstrated. The second part presents the development of a chemically amplified positive-tone fullerene based resists with the advantage of aqueous base solution development. Their lithographic capability is evaluated and discussed.
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Dunmore, Martin. "QoS provisioning in the next generation Internet : the role of the network edge." Thesis, Lancaster University, 2001. http://eprints.lancs.ac.uk/11949/.
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Luo, Xu. "Power system fault analysis based on intelligent techniques and intelligent electronic device data." Texas A&M University, 2003. http://hdl.handle.net/1969.1/5797.
Full textAbstract:
This dissertation has focused on automated power system fault analysis. New
contributions to fault section estimation, protection system performance evaluation
and power system/protection system interactive simulation have been achieved. Intelligent techniques including expert systems, fuzzy logic and Petri-nets, as well as
data from remote terminal units (RTUs) of supervisory control and data acquisition
(SCADA) systems, and digital protective relays have been explored and utilized to
fufill the objectives.
The task of fault section estimation is difficult when multiple faults, failures
of protection devices, and false data are involved. A Fuzzy Reasoning Petri-nets
approach has been proposed to tackle the complexities. In this approach, the fuzzy
reasoning starting from protection system status data and ending with estimation of
faulted power system section is formulated by Petri-nets. The reasoning process is
implemented by matrix operations. Data from RTUs of SCADA systems and digital
protective relays are used as inputs. Experiential tests have shown that the proposed
approach is able to perform accurate fault section estimation under complex scenarios.
The evaluation of protection system performance involves issues of data acquisition, prediction of expected operations, identification of unexpected operations and
diagnosis of the reasons for unexpected operations. An automated protection system performance evaluation application has been developed to accomplish all the tasks. The application automatically retrieves relay files, processes relay file data,
and performs rule-based analysis. Forward chaining reasoning is used for prediction
of expected protection operation while backward chaining reasoning is used for diagnosis of unexpected protection operations. Lab tests have shown that the developed
application has successfully performed relay performance analysis.
The challenge of power system/protection system interactive simulation lies in
modeling of sophisticated protection systems and interfacing the protection system
model and power system network model seamlessly. An approach which utilizes the
"compiled foreign model" mechanism of ATP MODELS language is proposed to model
multifunctional digital protective relays in C++ language and seamlessly interface
them to the power system network model. The developed simulation environment
has been successfully used for the studies of fault section estimation and protection
system performance evaluation.
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Cheung, Kai-man Felix, and 張繼文. "Efficient algorithms for semantic net construction and maintenance." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31227259.
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Al, Sayeed Choudhury Abdullah. "Characterization and experimental validation of reconfigurable optical adddrop multiplexers for next generation network." Thesis, University of Ottawa (Canada), 2006. http://hdl.handle.net/10393/27218.
Full textAbstract:
This thesis proposes a detailed design layout for the next generation optical metropolitan network to be equipped with Reconfigurable Optical Add/Drop Multiplexer (ROADM) subsystems. It demonstrates the key features of ROADM subsystems including the development of ring-to-ring interconnection in optical domain.
Simulation models are developed for the ROADM subsystems that can easily be configured according to the devices' available specification sheet. The developed simulation models have been verified with experimental measurements obtained from a reconfigurable all-optical metro network testbed. Such simulation modules will be valuable in planning and designing the next generation metro optical networks.
Combining the outcome of the research results presented in the thesis, a hybrid reconfigurable add/drop module is proposed. The proposed hybrid architecture can achieve lower loss among the existing 3rd generation ROADM modules. The functionality of ROADMs can also be improved by an Intelligent ROADM subsystem proposed for the next generation dynamically provisioned wavelength network.
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Kgwadi, Monageng. "Low-cost antennas and systems for next generation wireless communications." Thesis, University of Glasgow, 2017. http://theses.gla.ac.uk/8396/.
Full textAbstract:
This work presents a study of low-cost antennas and communication systems to support the burgeoning demand for bandwidth in the next generation wireless communications and networks (5G) and/or Internet of Things (IoT). The work was divided into three different fields all aimed at low-cost solutions of enabling next generation networks (5G) and IoT. The first part of the study involves study of low-cost fabrication of antennas and radio frequency (RF) guided wave structures up to 10 GHz using the thermal transfer printing (TTP) technique on renewable, light weight, flexible and low-cost substrates. The thermal transfer printing method for electronics was characterised from DC to 10 GHz and benchmarked for performance against inkjet printing technique which is an established technique for printed electronics. TTP achieved similar or better read range to inkjet printed radio frequency identification (RFID) antennas that were used in this study. Applications of the TTP method in IoT taking advantage of its speed and low cost were demonstrated by; producing on-demand antennas and/or rapid prototyping electronic designs, using off the shelf components to build a frequency agile antenna, and an ultra wideband antenna (UWB) for low power short range communications. The second part involves design and optimisation of a multi-port driven (MPD) slot-ring antenna for purposes of integration with resonant tunnelling diode (RTD) oscillators for millimetre-wave communications. The optimised structure managed airside radiation without the use of bulky lenses and achieved directivity of 10.8 dBi. The concept of the slot-ring with a backing ground plane was experimentally verified by a fabricated antenna for 5 GHz operation showing the expected performance. The third part is an experimental study of modulating RTD oscillators to deter- mine and improve achievable modulation bandwidth to meet 5G demands. Wireless transceiver systems at 28-40 GHz and 240 GHz were build using combinations of horn antennas, quasi-optical Schottky barrier diode detectors and some off-line signal processing. The modulation bandwidth of the oscillators were found to be limited to 300 Mbps and 16 Mbps for the 28-40 GHz oscillators and 220-300 GHz oscillators respectively due to oscillators being optimised for high power output instead of high modulation rates. Recommendations are made to improve the modulation datarate of these oscillators in order to meet the 5G datarate targets.
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Hegarty, Declan. "FPGA-based architectures for next generation communications networks." Thesis, University of Glasgow, 2008. http://theses.gla.ac.uk/455/.
Full textAbstract:
This engineering doctorate concerns the application of Field Programmable Gate Array (FPGA) technology to some of the challenges faced in the design of next generation communications networks. The growth and convergence of such networks has fuelled demand for higher bandwidth systems, and a requirement to support a diverse range of payloads across the network span. The research which follows focuses on the development of FPGA-based architectures for two important paradigms in contemporary networking - Forward Error Correction and Packet Classification. The work seeks to combine analysis of the underlying algorithms and mathematical techniques which drive these applications, with an informed approach to the design of efficient FPGA-based circuits.
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Garcia, Hernandez Juan Camilo. "Development of a Class D motor amplifier for a next-generation mechanism control electronics." Thesis, Luleå tekniska universitet, Rymdteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-60411.
Full textAbstract:
This thesis was written at Airbus DS GmbH in Friedrichshafen, Germany, as part of a project which aims to develop a new generation of class-D power amplification circuits for sinusoidal commutating motors controlling the movement of different mechanisms in satellites. Currently used topologies have disadvantages such as high power loss, analog controlling and high degree of signal distortion. This work first simulates available topologies which were previously developed by the company in order to compare them and build a trade-off list so the most suitable circuit is selected. Then, by further simulating and analysis several improvements to the circuit are suggested and a final schematic is developed including an analogue-to-digital converter and a total of three phases to power a motor. After a demonstrator circuit was designed and built, it was tested by using an external real time target machine to generate the corresponding PWM signals in correspondence to a controlling signal generated via Simulink. The final product of this thesis confirmed the simulation results such as an improved signal quality at higher frequencies in comparison to an available measurement from a previous generation circuit. The flexibility of the topology as well as the possibility of implementing a digital control was also confirmed during this phase of the project. Upon further work, the dimensioning of the output low pass filter should be improved and a digital PID controller should be implemented in the controlling FPGA. NOTE: This version of the Master Thesis deviates from the formal original submitted for examination in order not to disclose confidential information of Airbus DS GmbH. All positions in the document, where additional information was removed are properly identified. This document can be published according to the general rules of the Julius-Maximilians-Universität Würzburg and the Lulea University of Technology.This version of the Master Thesis deviates from the formal original submitted for examination in order not to disclose confidential information of Airbus DS GmbH. All positions in the document, where additional information was removed are properly identified. This document can be published according to the general rules of the Julius-Maximilians-Universität Würzburg and the Lulea University of Technology.
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Erbing, Axel. "In pursuit of next generation photovoltaics : An electronic structure study of lead-free perovskite solar cells." Licentiate thesis, Stockholms universitet, Fysikum, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-181608.
Full textAbstract:
The recent development of perovskite-based solar cells have shown a remarkably fast increase in power conversion efficiency making them a promising low-cost alternative to conventional cells. The most successful class of materials however, the lead-halide perovskites, are held back due to toxicity and stability issues significantly limiting their use. Because of this, the investigation of new, lead-free, light-absorber materials as a replacement is an important step towards improved solar cells. The focus of this licentiate thesis is the study of bismuth-based materials and their photovoltaic properties through electronic structure calculations. Specifically, the cubic-phase AgBi2I7 under gradual substitution of either bromine or antimony is investigated using density functional theory under periodic boundary conditions. This enables calculations of the system's energy levels and band structure. Furthermore, the energy variance of the employed model of the system is sampled with respect to its level of ion disorder to obtain a better understanding of the distribution of ions within the crystal. The materials are found to have good optical properties but comparatively low efficiencies. The introduced substitutions allow fine-tuning of the system's band gap and is shown to increase the overall performance of the solar cells. In addition, spin-orbit coupling effects are demonstrated to be important when treating these bismuth-based systems. The crystal structure is found to have a significant preference for separating its silver ions and cation vacancies.
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Fennell, Brett Jamerson. "Simultaneous solder reflow and underfill cure in next generation flip chip assembly." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/16681.
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Simpson, Robert E. "Chalcogenide thin film materials for next generation data storage." Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/52041/.
Full textAbstract:
Data can be stored in the form of amorphous and crystalline marks within a chalcogenide thin film. Commonly Ge. Therefore Ga:La:S:Cu shows potential as a future electrical phase change data storage material.
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Wu, Youwen. "Test-sequence generation for distributed systems specified in Petri-nets (with application to LOTOS)." Thesis, University of Ottawa (Canada), 1990. http://hdl.handle.net/10393/5654.
Full textAbstract:
This thesis proposes a new approach for the generation of test-sequences for indeterministic distributed systems. The system is specified in a Petri-net extended with internal and special labels so as to include the representation of indeterministic and unusual behaviours. Based on this extended model, a metric called 'degree of indeterminism' is developed for estimating the number of times a test sequence should be executed before a verdict can be made. A fairness model of conformance testing is then presented on the basis of this metric. Also, an iterative algorithm called IPNTEST is developed for generating test sequences and their degrees of indeterminism. The k$\sp{\rm th}$ iteration of IPNTEST generates groups of test sequences which all have the same length k. Test sequences belonging to a group have the same preamble, while different groups may have different preambles. Together, the test groups cover all the bounded feasible paths of the system under test. IPNTEST has been applied to generate test sequences for LOTOS specifications. Based on IPNTEST, an automatic test case generator call LOTOS-TCG has been implemented in the Sun Workstation.
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Churm, James. "Design and fabrication of a next generation regenerative neural interface." Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8198/.
Full textAbstract:
A Spiral Peripheral Neural Interface (SPNI) is an electrode array that has been previously presented as a regenerative neural interface capable of receiving information from, and transmitting information to nerves. The SPNI has previously been proven in concept, however, when stimulating nerves in the device, the electrodes areinsufficiently isolated from each other and stimulations can trigger unwanted neural activity in neighbouring channels of the SPNI. Along with this, neural interfaces generally, suffer from chronic viability problems, due to biological rejection. These issues were addressed in this thesis, by the addition of a PDMS silicone membrane, into the structure of the SPNI. Improvements to the understanding and performance of structural, electrical and biocompatibility aspects of the SPNI are addressed, with the addition of the PDMS film, which is used to electrically seal SPNI channels whilst not hindering conductor integrity. The inclusion ofPDMS also provides a platform which may enable drug delivery. This work dramatically improves SPNI performance whilst providing routes to improved biocompatibility. This thesis addresses the main issues previously presented in the SPNI and brings the device up to a new standard which can once again be tested for its viability in vivo.
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Glover, Garrett A. "The Next Generation Router System Cooling Design." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/191.
Full textAbstract:
Advancements in the networking and routing industry have created higher power electronic systems which dissipate large amounts of heat while cooling technology for these electronic systems has remained relatively unchanged. This report illustrates the development and testing of a hybrid liquid-air cooling system prototype implemented on Cisco’s 7609s router. Water was the working fluid through cold plates removing heat from line card components. The water was cooled by a compact liquid-air heat exchanger and circulated by two pumps. The testing results show that junction temperatures were maintained well below the 105°C limit for ambient conditions around 30°C at sea level. The estimated junction temperatures for Cisco’s standard ambient conditions of 50°C at 6,000 feet and 40°C at 10,000 feet were 104°C and 96°C respectively. Adjustments to the test data for Cisco’s two standard ambient conditions with expected device characteristics suggested the hybrid liquid-air cooling design could meet the projected heat load.
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Li, Man. "Applying decomposition and aggregation theory to the analysis of stochastic Petri nets and queueing networks." Thesis, University of Ottawa (Canada), 1992. http://hdl.handle.net/10393/7893.
Full textAbstract:
In this thesis, a class of Stochastic Petri Nets, called Local Balance Stochastic Petri Nets, and a class of queuing networks, called product form queueing networks are investigated. The parametric analysis of Stochastic Petri Nets in general is also studied. The major analysis tool used in this thesis is the Simon and Ando's Decomposition and Aggregation theory. Local Balance Stochastic Petri Nets have the property that their equilibrium state probability distributions have product form solutions. In this thesis, we extend the boundary of the Local Balance Stochastic Petri Nets, propose a systematic test procedure, as well as a C language program to identify this class of Stochastic Petri Nets, and prove that the Stochastic Petri Nets that have passed the test have product form solutions. Simon and Ando's Decomposition and Aggregation theory is then applied to the analysis of Local Balance Stochastic Petri Nets. A Decomposition by Subnet method is proposed. The analysis of a Local Balance Stochastic Petri Net is decomposed into the analysis of subnets. The results are combined to obtain the analysis for the original system. Through the Decomposition by Subnet method, a Norton's theorem for Local Balance Stochastic Petri Nets is developed. By decomposing according to a particular subnet, an aggregated net is constructed. This is that subnet with marking dependent firing rates. We show that the aggregated net may concisely and exactly represent the original Stochastic Petri Net. One of the applications of the Norton's theorem is to facilitate parametric analysis of Local Balance Stochastic Petri Nets. When a Stochastic Petri Net is not a Local Balance Stochastic Petri Net, the concept of "Ideal Aggregate" is used to develop efficient parametric analysis of it. By following a systematic way of constructing the infinitesimal matrix, the transition rate of interest is confined into a small diagonal submatrix. According to the algorithm, every time that particular rate takes a new value, only a Markov Chain of the order of the small diagonal submatrix needs to be analyzed. As a result, computational time requirements are greatly reduced. For the product form queueing networks, we first improve the efficiency of the Distribution Analysis by Chain (DAC) algorithm. We show that the calculation of marginal queue length distribution and throughput in each recursion may be avoided. As a result, computational time requirements are reduced. In addition, the improved algorithm has the benefits with regard to reducing possible numerical errors. Simon and Ando's Decomposition and Aggregation theory is used to develop an Independent Decomposition and Aggregation method for the analysis of product form queueing methods. The queueing network is first transformed into a network with nodes of Infinite Server types. That network is then decomposed independently chain by chain. Through the Independent Decomposition and Aggregation method, an algorithm called Adaptive Convolution By Chain (ACCAL) is derived. It is efficient in dealing with networks that have many chains and a few nodes. Compared with other algorithms, ACCAL has a smaller number of operations. In addition, ACCAL first converts the network into an equivalent one that may be analysed more efficiently. There are three independent parts in the algorithm that may be executed in parallel on a multiprocessor system to further improve the efficiency. The adaptive nature of the parallel processing characteristic distinguish ACCAL from other algorithms. (Abstract shortened by UMI.)