Analysis of the lateral diffuse metal-oxide semiconductor (LDMOS) power amplifier for cellular base stations

The primary purpose of this thesis was to present a theoretical large-signal analysis to study the power gain and efficiency of a microwave power amplifier for LS-band communications using software simulation. Power gain, efficiency, reliability, and stability are important characteristics in the power amplifier design process. These characteristics affect advance wireless systems, which require low-cost device amplification without sacrificing system performance. Large-signal modeling and input and output matching components are used for this thesis. Motorola's Electro Thermal LDMOS model is a new transistor model that includes self-heating affects and is capable of small-large signal simulations. It allows for most of the design considerations to be on stability, power gain, bandwidth, and DC requirements. The matching technique allows for the gain to be maximized at a specific target frequency. Calculations and simulations for the microwave power amplifier design were performed using Matlab and Microwave Office respectively. Microwave Office is the simulation software used in this thesis. The study demonstrated that Motorola's Electro Thermal LDMOS transistor in microwave power amplifier design process is a viable solution for common-source amplifier applications in high power base stations. The MET-LDMOS met the stability requirements for the specified frequency range without a stability-improvement model. The power gain of the amplifier circuit was improved through proper microwave matching design using input/output-matching techniques. The gain and efficiency of the amplifier improve approximately 4dB and 7.27% respectively. The gain value is roughly .89 dB higher than the maximum gain specified by the MRF21010 data sheet specifications. This work can lead to efficient modeling and development of high power LDMOS transistor implementations in commercial and industry applications.

Recanto do vale do pium: condomínio de habitações com ênfase no baixo impacto ambiental e no desempenho térmico do ambiente construído

This work describes the design process of a small recreational gated community in Pium, Nísia Floresta/RN, from concept to final design stages, with emphasis on low environmental impact, thermal comfort and the spatial quality of housing. The process consisted in a review of the literature and relevant standards, studies of design references and architectural programming. The project development was initially focused on the project’s feasibility, with the definition of the number of units, implantation, size and location of the dwellings and the common areas of the development. Two types of houses (four low rise and five duplex units) have been proposed in order to attend the premises of architectural programming. The conception of the architectural design began with the rooms’ zoning according to the lots. This resulted in the pre-selection of three alternatives that were evaluated in terms of spatial quality and environmental performance. The development of sketches focused on the envelope consistent with the bioclimatic guidelines and on the language of the compatible proposal with the lowest possible environmental impact of the building system, which resulted in the selection of the eucalyptus wood type. During the working drawings, the Quality Technical Regulation for the Level of Energy Efficiency Residential Buildings (RTQ -R) was adopted for the evaluation of the envelope, which resulted in "B" level of efficiency for the first case. After minor adjustments, mainly in frames, the efficiency level rose to "A", demonstrating that early project decisions contributed to the envelope energy performance. Besides the design of the two types of units, the final proposal of the gated community includes the design of the equipment for the common areas (entrance, multipurpose room and support and service sector), and the descriptive texts explaining the project and construction’s details.

Sobre formas e processos: projeto de um condomínio de casas a partir de princípios da gramática da forma

With the intention of studying and developing the design process based on a specific methodology, the object of this work is to present the design of a gated condominium community in Natal based on the application of principles of shape grammar, used in their design process. The shape grammar is a design method developed in the 1970s by George Stiny and James Gips. It is used for the analysis of the project as well as for its synthesis, with the goal of creating a "formal vocabulary" through mathematical and/or geometrical operations. Here, the methodology was used in the synthesis of the design process, through the relationship between formal subtractions and the houses’ architectural planning. As a result, five dwellings configurations were proposed, each one different from the other with respect to their shape and architectural programming, distributed in three twin groups, which are repeated until the final total of nine architectural volumes. In addition to studies of the condominium’s ventilation and the buildings’ shading simulations, studies of spatial flexibility and acoustic performance were also performed. The mapping of the design process, one of the specific objectives of the dissertation, was composed not only by the record of formal constraints (the preparation and application of rules), but also by physical, environmental, legal and sustainability aspects in relation to, on one hand, the optimization of the shading and passive ventilation for hot and humid climates, and, on the other hand, the modulation and rationalization of the construction.

Integração da simulação termoenergética com o processo de projeto: a análise de 6 casos

This work consists of the integrated design process analyses with thermal energetic simulation during the early design stages, based on six practical cases. It aims to schematize the integration process, identifying the thermal energetic analyses contributions at each design phase and identifying the highest impact parameters on building performance. The simulations were run in the DesignBuilder energy tool, which has the same EnergyPlus engine, validated. This tool was chosen due to the flexible and user friendly graphic interface for modeling and output assessment, including the parametric simulation to compare design alternatives. The six case studies energy tools are three architectural and three retrofit projects, and the author the simulations as a consultant or as a designer. The case studies were selected based on the commitment of the designers in order to achieve performance goals, and their availability to share the process since the early pre-design analyses, allowing schematizing the whole process, and supporting the design decisions with quantifications, including energy targets. The thermoenergetic performance analyses integration is feasible since the early stages, except when only a short time is available to run the simulations. The simulation contributions are more important during the sketch and detail phases. The predesign phase can be assisted by means of reliable bioclimatic guidelines. It was verified that every case study had two dominant design variables on the general performance. These variables differ according the building characteristics and always coincide with the local bioclimatic strategies. The adaptation of alternatives to the design increases as earlier it occurs. The use of simulation is very useful: to prove and convince the architects; to quantify the cost benefits and payback period to the retrofit designer; and to the simulator confirm the desirable result and report the performance to the client

Representações arquitetônicas na concepção projetual: um estudo com arquitetos e urbanistas do Rio Grande do Norte

The architect materializes his ideas using architectural representations that acts differently during the design process, as instrument that expresses his creatives ideas, as communication between the designer and the client, or as project documentation for its execution (DURAND, 2003). In this paper, it’s been discussed the connexion between the architectural representations and the design process, in a professional context, focusing on representation as an aid to conception. The general aim is to understand the role of architectural representations in the design process by identifying ways of appropriation of their types and resources. The investigation was developed through the theoretical and conceptual studies about the mentioned themes, and the empirical and qualitative research, with architects from the state of Rio Grande do Norte, Brazil, which was developed in two stages: the first one, by filling an electronic form, and the second one, by case studies through execution of design exercises. The results of indirect research showed that the majority of architects and urbanists believes that the way it use the types and representation resources may interfere in design concept. And, after the completion of the case studies, was showed that, motivated by different design conditions, most designers has used the representations differently, which is reflected in different design conceptions.

Repercussão da integração de conteúdos das disciplinas nos trabalhos finais de graduação de CAU-UFRN (2003 a 2010)

The changes in the teaching of Architecture in Brazilian Universities, from the 1990s onwards, with the upgrading of the Architecture project as an object of research and scientific knowledge and more specifically, the adoption by the Architecture and Urbanism Course (CAU) from the Federal University of Rio Grande do Norte (UFRN) of the principle of content integration of the disciplines, aroused the interest in research on issues related to the Design process and the teaching of design in this context. After 20 years of its implementation and recognized as being a major step forward in teaching the teaching/learning process, the integration is the central focus of this research, which will seek to identify changes in the teaching design and its refutation in projects developed by students at the end of their course. In general, it is understood that the need to integrate knowledge from diverse areas of Architect’s professional activity, who seeks through an exercise of summary, identify solutions to the issues involved in a project. On the assumption that the integration of content of disciplines fosters the teaching/learning of Architecture project, which can be evident in the Final Course Assignment (FCA), it becomes necessary to understand, in the light of theories of education, such as the principles of curriculum organization, such as interdisciplinarity and multidisciplinarity, transdisciplinarity and transversality are related to the term integration, is more understood and disseminated among the professors of the Architecture courses. The object of this study is consequently the relationship between the integration of subject content and Architecture projects developed by students from CAU-UFRN, in the context of Final Graduation projects (FCAs) completed in the period of duration of the Teaching Project A5-from 2003. The study has the main objective of investigating to what extent the integration of disciplinary content affects the development of the Final Assignment of UFRN, from the analysis of drawings and texts of the projects of the learners and the testimonies of teachers and undergraduate students. From a methodological point of view, the research “Architecture, Project and Knowledge Production: Academic Production – FCAs, Thesis and dissertations in PA/Brazil” carried out by the PROJETAR/UFRN team has been adopted as the basis for the construction of the analytical instruments. In order to identify aspects of their experience by various actors which were not recorded in FCA, electronic forms were applied between teachers and students, through the internet. The integration of subject content based Teaching Project of CAU-UFRN institutionalises the interdisciplinarity, organizing the curriculum by thematic semesters, in which the disciplines work the same focus and at the same site. The integrated work which derives from there tries to articulate the content of each discipline of the period and represents a general practice and has been evaluated by teachers and students, and considered as a facilitator of the teaching/learning process. The analysis of the data collected from the textual content and graphic of the sample of FCAs of CAU-UFRN suggests that the content of the various areas of knowledge are assimilated by the student and used as a resource for the design and development of Architecture projects. In other words, there is in the end product of the students record of the integration of content, whether in speech or in drawing, reaffirming the importance of the convergence of various knowledge in the Architectonic project. However, the integration of content from the point of view of their articulation and operationalization, which involves teachers and students in the same period, has as a condition sine qua non for the success of this educational principle, the provision of these to work as part of a team, for the dialogic practice, which creates areas of intersection not only between disciplines, but between the knowledge of each of the participants.

Atmosferas arquitetônicas: projeto e percepção na obra de Peter Zumthor

This thesis will discuss the topic architectural atmospheres, based on Peter Zumthor's works and narrative. The subject "architectural atmospheres" is defined in the study as the "complex and general condition, realized by the user during the experience of a place". Atmospheres are composed of the overlap of all physical qualities that compound a space and its perception, conditioned by individual issues of the user. The atmosphere is realized through all human body receivers, in a multi-sensorial process, and affects qualitatively the spacial experience of the places created by architecture. The study has three chapters. The first chapter is a reflection on the issues that architectural atmospheres present. It passes through the concept and definition of the subject and includes a compilation of design principles that act on the architectural atmosphere composition in a variety of projects by a range of professionals. In the second chapter, the procedures adopted by Peter Zumthor in his design process that focus on atmosphere composition are studied. In the third and last chapter, Brother Claus Chapel (Wachendorf, German) and Kolumba Museum (Colon, German) projects, both by Peter Zumthor, are analyzed, in order to comprehend the complex role of elements that constitute the architectural atmosphere of each of these places. The methodology used throughout the thesis consists of bibliography and documental analysis, based on books, plans and material searched on Internet. Furthermore, the project analysis counted with the personal experience of the author of this thesis upon visiting the studied buildings. Finally, in conclusion, it is realized that when architecture is made in order to touch the user, expressed by its built objects, it can be provide a vast conceptual and theoretical basis that valorizes and enriches the experience of its use. It (the architectural atmosphere) is related to an approach that uses the same elements of any other construction, but distinguishes itself by the connections that it implies with humans and its environment. In the face of new patterns unveiled for contemporary architecture, this study contribution is based around the opportunity to understand this particular relationship between user and architectural object, identified as a phenomenological approach of architecture, as well as to update the subject bibliography, still scarce among Brazilian universities.

O desempenho da compartimentação horizontal seletiva na promoção da segurança contra incêndio em edificações

The thesis presents the results of research that addresses the performance of selective horizontal partitioning to promote Fire Safety in Buildings - FSB. Horizontal partitioning is a passive protection measure, settable in the early stages of the design process and controlled by the architect. However, there is a frequent reconfiguration of the rooms in academic buildings to adjust them for the space demand. Thus, large classrooms could turn into two or more smaller rooms, for example. Regardless when the subdivision occurs in the design phase or during the occupation of the building, the regulations just ensures the compartimentation of the room if all fireguard devices are present in the room. Knowing the fire's first minutes are the most important for life protection, we defend the hypothesis that a kind of partitioning ignored by regulatory standards is able to favoring the building vacancy and occupants rescue, for promote the room’s smoke exhaust. The performance of the selective horizontal partitioning due different blend of openings for smoke outlet was simulated on CFD software. The results indicate that selective horizontal partitioning is able to promote an upper smoke free layer and delay the indoor temperature growth.

O desempenho da compartimentação horizontal seletiva na promoção da segurança contra incêndio em edificações

The thesis presents the results of research that addresses the performance of selective horizontal partitioning to promote Fire Safety in Buildings - FSB. Horizontal partitioning is a passive protection measure, settable in the early stages of the design process and controlled by the architect. However, there is a frequent reconfiguration of the rooms in academic buildings to adjust them for the space demand. Thus, large classrooms could turn into two or more smaller rooms, for example. Regardless when the subdivision occurs in the design phase or during the occupation of the building, the regulations just ensures the compartimentation of the room if all fireguard devices are present in the room. Knowing the fire's first minutes are the most important for life protection, we defend the hypothesis that a kind of partitioning ignored by regulatory standards is able to favoring the building vacancy and occupants rescue, for promote the room’s smoke exhaust. The performance of the selective horizontal partitioning due different blend of openings for smoke outlet was simulated on CFD software. The results indicate that selective horizontal partitioning is able to promote an upper smoke free layer and delay the indoor temperature growth.

designing + (dis)assembling disputes: an ethnography of disputes & lawyers in the construction industry

The UK construction industry is notorious for the sheer amount of disputes which are likely to arise on each building and engineering project. Despite numerous creative attempts at “dispute avoidance” and “dispute resolution”, this industry is still plagued with these costly disputes. Whilst both academic literature and professional practices have investigated the causes of disputes and the mechanisms for avoidance/resolution of these disputes, neither has studied in any detail the nature of the construction disputes and why they develop as they do once a construction lawyer is engaged. Accordingly, this research explores the question of what influences the outcome of a construction dispute and to what extent do construction lawyers control or direct this outcome? The research approach was ethnographic. Fieldwork took place at a leading construction law firm in London over 18 months. The primary focus was participant observation in all of the firm’s activities. In addition, a database was compiled from the firm’s files and archives, thus providing information for quantitative analysis. The basis of the theoretical framework, and indeed the research method, was the Actor‐Network Theory (ANT). As such, this research viewed a dispute as a set of associations – an entity which takes form and acquires its attributes as a result of its relations with other entities. This viewpoint is aligned with relational contract theories, which in turn provides a unified platform for exploring the disputes. The research investigated the entities and events which appeared to influence the dispute’s identity, shape and outcome. With regard to a dispute’s trajectory, the research took as its starting point that a dispute follows the transformation of “naming, blaming, claiming…”, as identified by Felstiner, Abel and Sarat in 1980. The research found that construction disputes generally materialise and develop prior to any one of the parties approaching a lawyer. Once the lawyer is engaged, we see the reverse of the trajectory “naming, blaming, claiming…” this being: “claiming, blaming, naming…” The lawyers’ role is to identify or name (or rename) the dispute in the best possible light for their client in order to achieve the desired outcome – the development of which is akin to the design process. The transformation of a dispute and the reverse trajectory is by no means linear, but rather, iterative and spatial as it requires alliances, dependencies and contingencies to assemble and take the shape it does. The research concludes that construction disputes are rarely ever completely “resolved” as such. Whilst an independent third party may hand down a judgment, or the parties may reach a settlement agreement, this state is only temporal. Some construction disputes dissipate whist others reach a state of hibernation for a period of time only to pick up momentum and energy some years later. Accordingly, this research suggests that the concept of “dispute resolution” does not exist in the UK construction industry. The ultimate goal should be for parties to reach this ultimate and perpetual state of equilibrium as quickly and as cost effectively as possible: “dispute dissolution”, the slowing down of the dispute’s momentum. Rather than focusing on the design and assemblage of the dispute, the lawyers’ role therein is, or should be, to assist with the “disassembling” of the dispute.

Intelligent DMU creation: Nominal CAD model preparation for automated tolerance allocation

This paper examines the integration of a tolerance design process within the Computer-Aided Design (CAD) environment having identified the potential to create an intelligent Digital Mock-Up [1]. The tolerancing process is complex in nature and as such reliance on Computer-Aided Tolerancing (CAT) software and domain experts can create a disconnect between the design and manufacturing disciplines It is necessary to implement the tolerance design procedure at the earliest opportunity to integrate both disciplines and to reduce workload in tolerance analysis and allocation at critical stages in product development when production is imminent.
The work seeks to develop a methodology that will allow for a preliminary tolerance allocation procedure within CAD. An approach to tolerance allocation based on sensitivity analysis is implemented on a simple assembly to review its contribution to an intelligent DMU. The procedure is developed using Python scripting for CATIA V5, with analysis results aligning with those in literature. A review of its implementation and requirements is presented.

FPGA-based soft-core processors for image processing applications

With security and surveillance, there is an increasing need to process image data efficiently and effectively either at source or in a large data network. Whilst a Field-Programmable Gate Array (FPGA) has been seen as a key technology for enabling this, the design process has been viewed as problematic in terms of the time and effort needed for implementation and verification. The work here proposes a different approach of using optimized FPGA-based soft-core processors which allows the user to exploit the task and data level parallelism to achieve the quality of dedicated FPGA implementations whilst reducing design time. The paper also reports some preliminary
progress on the design flow to program the structure. An implementation for a Histogram of Gradients algorithm is also reported which shows that a performance of 328 fps can be achieved with this design approach, whilst avoiding the long design time, verification and debugging steps associated with conventional FPGA implementations.

Assessment of turbulence model predictions for a centrifugal compressor simulation

Steady-state computational fluid dynamics (CFD) simulations are an essential tool in the design process of centrifugal compressors. Whilst global parameters, such as pressure ratio and efficiency, can be predicted with reasonable accuracy, the accurate prediction of detailed compressor flow fields is a much more significant challenge. Much of the inaccuracy is associated with the incorrect selection of turbulence model. The need for a quick turnaround in simulations during the design optimisation process, also demands that the turbulence model selected be robust and numerically stable with short simulation times.
In order to assess the accuracy of a number of turbulence model predictions, the current study used an exemplar open CFD test case, the centrifugal compressor ‘Radiver’, to compare the results of three eddy viscosity models and two Reynolds stress type models. The turbulence models investigated in this study were (i) Spalart-Allmaras (SA) model, (ii) the Shear Stress Transport (SST) model, (iii) a modification to the SST model denoted the SST-curvature correction (SST-CC), (iv) Reynolds stress model of Speziale, Sarkar and Gatski (RSM-SSG), and (v) the turbulence frequency formulated Reynolds stress model (RSM-ω). Each was found to be in good agreement with the experiments (below 2% discrepancy), with respect to total-to-total parameters at three different operating conditions. However, for the off-design conditions, local flow field differences were observed between the models, with the SA model showing particularly poor prediction of local flow structures. The SST-CC showed better prediction of curved rotating flows in the impeller. The RSM-ω was better for the wake and separated flow in the diffuser. The SST model showed reasonably stable, robust and time efficient capability to predict global and local flow features.

Laboratory performance evaluation of CIR-emulsion and its comparison against CIR-foam test results from Phase III, TR-578

Currently, no standard mix design procedure is available for CIR-emulsion in Iowa. The CIR-foam mix design process developed during the previous phase is applied for CIR-emulsion mixtures with varying emulsified asphalt contents. Dynamic modulus test, dynamic creep test, static creep test and raveling test were conducted to evaluate the short- and long-term performance of CIR-emulsion mixtures at various testing temperatures and loading conditions. A potential benefit of this research is a better understanding of CIR-emulsion material properties in comparison with those of CIR-foam material that would allow for the selection of the most appropriate CIR technology and the type and amount of the optimum stabilization material. Dynamic modulus, flow number and flow time of CIR-emulsion mixtures using CSS-1h were generally higher than those of HFMS-2p. Flow number and flow time of CIR-emulsion using RAP materials from Story County was higher than those from Clayton County. Flow number and flow time of CIR-emulsion with 0.5% emulsified asphalt was higher than CIR-emulsion with 1.0% or 1.5%. Raveling loss of CIR-emulsion with 1.5% emulsified was significantly less than those with 0.5% and 1.0%. Test results in terms of dynamic modulus, flow number, flow time and raveling loss of CIR-foam mixtures are generally better than those of CIR-emulsion mixtures. Given the limited RAP sources used for this study, it is recommended that the CIR-emulsion mix design procedure should be validated against several RAP sources and emulsion types.

Rockalbumets grafik : Återkommande designelement och landstypiska utseenden – en visuell innehållsanalys

För att ge insikt hur design för ett nytt rockalbum ska ske och ge information kring vad som bör finnas med på ett nytt omslag har denna studie utförts. Studien framförde information om att albumsgrafik var relevant. Först sades det att en nedåtgående trend gick att anta, eftersom den digitala musikbranschen tog över från den fysiska. Men det visade sig därefter vara precis lika stor försäljning på de fysiska albumen som de digitala. För att besvara målen i studien utfördes en visuell innehållsanalys och informationssökning på internet. Studiens syfte var att visuellt granska rockalbum från tre olika ursprungsländer, som var Sverige, Storbritannien och USA. Genom analysen kategoriserades designelement, teman och framtogs landstypiska albumomslag. Studien berörde även vem som styr designen av ett omslag samt ifall det kunde ses någon tongivande designer bland de album som ingick i analysen. I slutsatsen framgick det att Storbritannien och USA hade mycket lika grafiskt manér och att omslag från Sverige såg annorlunda ut. Det framgick även att banden styr utseendet på omslaget mer än designern, och från analysen framgick inte någon tongivande designer.