Rozprawy doktorskie na temat „Design criteria”

The fish farming industry faces some problems for the future as the escaping of fish and fish lice. One solution to these problems could be to move the farms further offshore. The main focus of the industry is on the cages the fish is held in, but the feed barge is the brain of a fish farm. Before offshore fish farming is an acceptable solution for the future the design criteria for the feed barge has to be sufficient for more exposed areas.Some regulations both for fish farming and the oil industry have been evaluated. The conclusion from the evaluation of the regulations is that the regulation for floating fish farms is the least strict regulation. The purpose of this report is to enlighten the need for new thinking for design criteria for offshore feed barges by doing a hydrodynamic analysis in HydroD by using WADAM and potential theory applied to a panel model. The computer program is a recognized program developed by DNV. The model in this report is a design which is believed to be the best design for exposed areas. The model is analyzed in both hydrostatic and hydrodynamic conditions. The hydrostatic analyses conclude that the barge is stable and valid for operation in Norwegian waters. For the hydrodynamic analysis it as assumed two different locations with different wave data to enlighten the need to design a barge to a specific location. There is also assumed extra restoring as simulation of mooring. The result from the hydrodynamic analyses is used to evaluate the required freeboard for each location and the motions and accelerations of the barge. The results show that the barge in both locations will experience water on deck already for significant wave height of 2 meters, which actually is low even for the regulations today. The rotation and acceleration results are compared against limits for human tolerance and they show that there is a need for evaluating this in the design criteria.The conclusion is that the regulation valid today for fish farming is insufficient for offshore fish farming and that it is possible to look towards the offshore industry for leads on how the regulations should be formed. For the future it would be appropriate to change the design criteria and design of the feed barge if the fish farming is to be moved further offshore.

The research contained in this thesis provides an investigation into a new method of minimising the perceptual differences when encoding digitised speech. An application of the perceptual criteria is described in the context of a codebook encoding methodology Some of the background studies covered aspects of psychoacoustics, in particular the effects of the human outer, middle and inner ear. Models approximating each region of the ear are utilised and concatenated into a single overall auditory response path model. As the objective of the research is to encode and decode speech waveforms, some study into how speech is produced and the classification of speech sounds is required. From this there is a description of a basic speech production model which is modelled as a digital filter. A review of the main categories for coding schemes that are currently employed is presented along with commonly used coding methods. In particular the codebook coding method is reviewed in sufficient detail to contrast with the new coding method. The development of a new perceptual minimisation criterion which relies on dual application of the auditory response path model on the original and reconstructed speech waveforms is described. In this the ordering of eodebook searches, the frequency spectrum used as the search target, windowing functions with durations and placement are all analysed to determine the optimum encoder design. Also described are a number of prospective gain algorithms which cover both time and frequency domain implementations. A new encoder is constructed which fully integrates the new perceptual criterion into the minimisation of the original and reconstructed speech waveforms. In the minimisation no part of the traditional encoder method is used, however both methods use a similar technique for determining gain factors. Speech derived from both encoders was subjectively assessed by a number of untrained, independent listeners. The results presented show that both methods are comparable but there is a slight preference towards the traditional encoder. A measure of the complexity indicated that the new minimisation method is also more complex than the traditional encoder.

Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, March 2005.
Thesis Advisor(s): Fotis Papoulias, Roman B. Statnikov. Includes bibliographical references (p. 241). Also available online.

The amount of total and relative sway of a framed or a composite (frame-shear wall) building is of utmost importance in assessing the seismic resistance of the building. Therefore, the design engineer must calculate the sway profile of the building several times during the design process. However, it is not a simple task to calculate the sway of a three-dimensional structure. Of course, computer programs can do the job, but developing the three-dimensional model becomes necessary, which is obviously tedious and time consuming. An easy to apply analytical method is developed, which enables the determination of sway profiles of framed and composite buildings subject to seismic loading. Various framed and composite three-dimensional buildings subject to lateral seismic loads are solved by SAP2000 and the proposed analytical method. The sway profiles are compared and found to be in very good agreement. In most cases, the amount of error involved is less than 5 %. The analytical method is applied to determine sway magnitudes at any desired elevation of the building, the relative sway between two consecutive floors, the slope at any desired point along the height and the curvature distribution of the building from foundation to roof level. After sway and sway-related properties are known, the requirements of the Turkish Earthquake Code can be evaluated and / or checked. By using the analytical method, the amount of shear walls necessary to satisfy Turkish Earthquake Code requirements are determined. Thus, a vital design question has been answered, which up till present time, could only be met by rough empirical guidelines. A mathematical derivation is presented to satisfy the strength requirement of a three-dimensional composite building subject to seismic loading. Thus, the occurrence of shear failure before moment failure in the building is securely avoided. A design procedure is developed to satisfy the stiffness requirement of composite buildings subject to lateral seismic loading. Some useful tools, such as executable user-friendly programs written by using &ldquo
Borland Delphi&rdquo
, have been developed to make the analysis and design easy for the engineer. A method is also developed to satisfy the ductility requirement of composite buildings subject to lateral seismic loading based on a plastic analysis. The commonly accepted sway ductility of &
#956
&
#916
=5 has been used and successful seismic energy dissipation is thus obtained.

Approved for public release, distribution is unlimited
Numerous optimization problems involve systems with multiple and often contradictory criteria. Such contradictory criteria have been an issue for marine/naval engineering design studies for many years. This problem becomes more important when one considers novel ship types with very limited or no operational record. A number of approaches have been proposed to overcome these multiple criteria design optimization problems. This Thesis follows the Parameter Space Investigation (PSI) technique to address these problems. The PSI method is implemented with a software package called MOVI (Multi-criteria Optimization and Vector Identification). Two marine/naval engineering design optimization models were investigated using the PSI technique along with the MOVI software. The first example was a bulk carrier design model which was previously studied with other optimization methods. This model, which was selected due to its relatively small dimensionality and the availability of existing studies, was utilized in order to demonstrate and validate the features of the proposed approach. A more realistic example was based on the "MIT Functional Ship Design Synthesis Model" with a greater number of parameters, criteria, and functional constraints. A series of optimization studies conducted for this model demonstrated that the proposed approach can be implemented in a naval ship design environment and can lead to a large design parameter space exploration with minimum computational effort.
Lieutenant Junior Grade, Turkish Navy

System architecture is defined as the description of a complex system in terms of its functional requirements, physical elements and their interrelationships. Designing a complex system architecture can be a difficult task involving multi-faceted trade-off decisions. The system architecture designs often have many project-specific goals involving mix of quantitative and qualitative criteria and a large design trade space. Several tools and methods have been developed to support the system architecture design process in the last few decades. However, many conventional problem solving techniques face difficulties in dealing with complex system design problems having many goals. In this research work, an interactive multi-criteria design optimization framework is proposed for solving many-objective system architecture design problems and generating a well distributed set of Pareto optimal solutions for these problems. System architecture design using multi-criteria optimization is demonstrated using a real-world application of an aero engine health management (EHM) system. A design process is presented for the optimal deployment of the EHM system functional operations over physical architecture subsystems. The EHM system architecture design problem is formulated as a multi-criteria optimization problem. The proposed methodology successfully generates a well distributed family of Pareto optimal architecture solutions for the EHM system, which provides valuable insights into the design trade-offs. Uncertainty analysis is implemented using an efficient polynomial chaos approach and robust architecture solutions are obtained for the EHM system architecture design. Performance assessment through evaluation of benchmark test metrics demonstrates the superior performance of the proposed methodology.

This research provides a critical link to ensure designers remain at the forefront of developing safe, sustainable and innovative products and services in the future. The four key findings of this research contribute to the advancement of knowledge and provide an understanding of the relationships between designers' co-evolution approach and their use of analogy. The behavioural relationships between sketching and gesture were investigated. The outcome of this research is a Design Activity Framework. This framework demonstrates a novel understanding how designers design by concentrating on co-evolution, problem-framing and solution seeking.

New road infrastructure projects are important and constitute of large investments that have to serve the society for a long time. The investments have to be durable at the lowest life cycle cost and the pavements have to sustain loads from increasing traffic intensity and heavy traffic loads. In Sweden less than 1 ‰ of the national road network consists of concrete pavements. In parts of Europe and in the U.S., on the other hand, concrete roads are used to a large extent for highways as well as rural roads. To encourage the competition between different road materials in Sweden, the tools for designing robust concrete pavements have to be brought forward. In order to emphasize plain concrete pavements as an alternative in road construction, the design must also be competitive.

The current Swedish design method for concrete pavements is straightforward but offers no flexibility when designing roads with, for instance higher traffic loads. The method calculates concrete thicknesses on the conservative side since only a limited number of parameters are treated. Modern methods that take into account many more parameters in the design are being developed internationally. For a new Swedish design method, these parameters have to be established for actual conditions in Sweden. Also, the design has to be flexible and meet the demands from contractors and clients for a wider use.

The aim of this project is to develop a new design method for plain concrete pavements that is more flexible than today. A new design method is also intended for the Swedish Road Administrations’ (SRA) computer based public design guide, PMS Objekt.

Information for a new design method has been assembled mainly by investigating two newly developed design methods, VENCON2.0 in the Netherlands, and the Mechanistic-Empirical Pavement Design Guide (MEPDG) in the USA. Comparative calculations between the Swedish design method and the MEPDG are presented. The comparison is made on the level of input parameters and highlights the advantageous aspects of a semi-mechanistic design procedure where the functional properties of a concrete pavement are calculated incrementally over the design period.

Plain and lean concrete, separately, but also the in composite beams, have been studied in flexural fatigue testing. The results show that Tepfers’ fatigue criterion is valid for both plain and lean concrete when subjected to flexural fatigue loading. The results also show that the fatigue strength of composite beams of plain and lean concrete is mainly dependent on the strength of the lean concrete but that Tepfers’ fatigue criterion is applicable. The bond between plain in lean concrete is found to be strong and fatigue resistant, making the composite section able to accommodate higher stresses. The bond nevertheless contributes to the risk for reflection cracks in the plain concrete wear layer and a recommendation to focus on stresses in the bottom of the lean concrete is formulated. Also, well distributed expansion joints in the lean concrete are necessary.

A new project for measuring temperature gradients for use in concrete pavement design is also presented. This is done with means of concrete prisms placed in the pavement and are done in order to establish actual temperature gradients for various locations in Sweden. Also, the nonlinear gradients that act in the pavement as well as the negative temperature gradients will be analysed for the use in the design.

Finally, the thesis outlines a new design method for Swedish conditions. The method is possible to develop gradually and is based on FE-analysis for fast computations. In the design, stresses from traffic and temperature loads are calculated simultaneously in a number of critical locations in the concrete slab. The method will also make it possible to alter design features as slab lengths and widths, with various connections between the slabs.

A semi-batch Direct Coal Liquefaction facility was designed and constructed in order to examine the impact of process variables on coal liquefaction kinetics. A series of parametric investigations involving bituminous, sub-bituminous coals and lignite were performed. The process variables included solvent composition, catalyst to coal ratio, the intensity of turbulence, the initial dissolved hydrogen concentration, and the slurry residence time distribution. The results of these investigations showed that process variables have a significant impact on the rates of liquefaction reactions, and that reaction rates for coal and lignite are affected in a similar manner. The overall rate and maximum extent of liquid and gas production was found to depend on the initial rate of molecular hydrogen transfer to the coal particles, and on the ratio of the intensity of turbulence to the level of catalysis. This latter finding led to the discovery of a persistent dispersed liquid phase within the coal liquefaction environment. A reaction model, coupling these findings with a simple kinetic scheme, was found to correlate the liquefaction behaviour of bituminous and sub-bituminous coals and lignite, in diverse reaction environments. The experimental results and the reaction model were used to develop novel design criteria for Direct Coal Liquefaction Reactors. Two design optima were identified. One optimum is closely approximated by an existing process. An alternative and potentially preferable optimum is proposed.
Applied Science, Faculty of
Mining Engineering, Keevil Institute of
Graduate

In recent years, the chemical and pharmaceutical industries have faced increased development times and costs with fewer novel chemicals being discovered. This has resulted in many companies focusing on innovative research and development as they consider this key to business success. In particular, a number of leading industrial organisations have adopted the principles of Whole Process Design (WPD). WPD considers the optimisation of the entire product development process, from raw materials to end product, rather than focusing on each individual unit operation. The complexity involved in the implementation of WPD requires rationalised decision-making, often with limited or uncertain information. This thesis assesses the most widely applied methods in Multi-Criteria Decision Analysis (MCDA) in conjunction with the results of two interviews and two questionnaires that identified the industrial requirements for decision-making during WPD. From the findings of this work, a novel decision-making methodology was proposed, the outcome of which allows a decision-maker to visually interpret their decision results with associated levels of uncertainty. To validate the proposed methodology, a software framework was developed that incorporates two other decision-making approaches, the Analytical Hierarchy Process (AHP) and ELimination Et Choix Traduisant la REalité trois (ELECTRE III). The framework was then applied to a number of industrial case studies to validate the application of the proposed methodology.

Mixing is a key process in microfluidic systems since that samples and reagents generally need to be mixed thoroughly before chemical or biological analysis or reactions. Micromixers are designed to fulfil this critical process. In general, the development of microdevices is a competitive field that requires from researchers shorter times and lower costs in prototyping. Computational Fluid Dynamics (CFD) helps in reducing the time from concept to device design. Intuition and experience of the designer is usually behind its application on design improvement, by analyzing some physical variables to determine the effect of design parameters and to adjust them accordingly to the pursued objectives. In this thesis, a design and optimization strategy is presented and used for the analysis and design of micromixers. The method systematically integrates CFD with an optimization strategy based on the use of Design of Experiments, Surrogate Modelling and Multi-Objective Genetic Algorithm techniques. The aim is to define optimum designs that give the trade-off of the performance parameters, which in this study are the mixing index, defined on the basis of mass concentration distribution, and the pressure drop in the microchannel. Three types of micromixers have been studied and their geometric parameters have been optimized. They are the Staggered Herringbone Mixer and two novel designs, a planar micromixer with baffles in the microchannel and a 3-D T-type micromixer. A completed fabrication method was implemented as part of this thesis work and it was used to fabricate some of the micromixers. Experimental measurements and published data have been used to validate the numerical results. The outcomes of this thesis demonstrate that using advanced optimisation techniques on the basis of CFD solutions and analyses allows the design of optimum micromixers for different operation conditions, which can be set by the designer, without being necessary to use a referential design to start the method.

Analysis indicates that the Blasius equation yields accurate estimates of head loss in small diameter plastic tubing and larger diameter PVC pipe for Reynolds numbers upto 100,000. The Hazen-Williams equation with suitable roughness parameter values also predicts head loss accurately. The results of laboratory experiments reveal that the undulations which are created during field installation are the primary cause of air locking in the delivery hose. The additional head needed to release the trapped air was found to be equal to the sum of heights of all the undulations. If the sum of their heights exceeds the design head loss in the delivery hose, air locking will result. The capital investment for bubbler system under study was comparable to that of a pressurized drip system. Long term savings in terms of energy and maintenance make low head bubbler systems an attractive alternative to pressurized drip systems for irrigating orchards or vineyards.

Les modèles de conception des chaînes logistiques sont devenus de plus en plus complexes, à cause de l'environnement économique incertain et l'introduction de nouveaux critères de décision tels que : l'aspect environnemental, l'aspect social, l'aspect législatif, l'aspect économique, la satisfaction du client et la prise en compte des risques. Répondre aux changements qui touchent les chaînes logistiques exige de composer avec des incertitudes et des informations incomplètes. Configurer des chaînes logistiques multicritères avec prise en compte des incertitudes peut garantir la continuité des activités de l'entreprise.L'objectif principal de cette thèse est la conception de chaînes logistiques multicritères qui résistent aux changements et l'instabilité des marchés. Le manuscrit de cette thèse s'articule autour de sept principaux chapitres:1 - introduction.2 - Etat de l'art sur la conception des chaînes logistiques.3 -Conception des chaînes logistiques multicritères en mesure de répondre aux nouveauxcritères économiques, sociaux, environnementaux et législatifs.4 - Conception des chaînes logistiques multi-objectifs.5 - Développement d'une heuristique de résolution des problèmes de conception deschaînes logistiques de taille réelle.6 - Conception des chaînes logistiques avec prise en compte des incertitudes.7 - Conclusions et perspectives
This thesis contributes to the debate on how uncertainty and concepts of sustainable development can be put into modern supply chain network and focuses on issues associated with the design of multi-criteria supply chain network under uncertainty. First, we study the literature review , which is a review of the current state of the art of Supply Chain Network Design approaches and resolution methods. Second, we propose a new methodology for multi-criteria Supply Chain Network Design (SCND) as well as its application to real Supply Chain Network (SCN), in order to satisfy the customers demand and respect the environmental, social, legislative, and economical requirements. The methodology consists of two different steps. In the first step, we use Geographic Information System (GIS) and Analytic Hierarchy Process (AHP) to buildthe model. Then, in the second step, we establish the optimal supply chain network using Mixed Integer Linear Programming model (MILP). Third, we extend the MILP to a multi-objective optimization model that captures a compromisebetween the total cost and the environment influence. We use Goal Programming approach seeking to reach the goals placed by Decision Maker. After that, we develop a novel heuristic solution method based on decomposition technique, to solve large scale supply chain network design problems that we failed to solve using exact methods. The heuristic method is tested on real case instances and numerical comparisons show that our heuristic yield high quality solutions in very limited CPU time. Finally, again, we extend the MILP model presented before where we assume that the costumer demands are uncertain. We use two-stage stochastic programming approach to model the supply chain network under demand uncertainty. Then, we address uncertainty in all SC parameters: opening costs, production costs, storage costs and customers demands. We use possibilistic linear programming approach to model the problem and we validate both approaches in a large application case

Nowadays, the interest in the synchronous reluctance machines is growing up due to their several merits in comparison to other machine types. These machines offer high torque density with respect to the induction machines. Their torque density is slightly lower than permanent magnet synchronous machines even though the lower performance is compensated by a much cheaper rotor. Since synchronous reluctance machines do not induce voltage when the stator is not supplied, there are not short circuit currents and braking torques due to the electrical faults, e.g. they have high fault tolerant capability. In addition, synchronous reluctance machine has a robust structure, and a wide constant power speed range. For these aforementioned reasons, these machines are employed in several applications. However, there is a prominent defect of this kind of machines which is the low power factor. This defect is addressed by assisting the motor by permanent magnets within the flux barriers of the rotor leading to the permanent magnet assisted synchronous reluctance motor. In addition, these kinds of machines has high torque ripple. This is due to the high harmonic content in the magneto motive force which interacts with the rotor anisotropy. Several approaches are proposed to reduce the torque ripple, such as: (a) using skewed rotor, (b) adopting two different flux-barrier geometries in the same lamination, i.e., asymmetric rotor, (c) using equally spaced the flux-barrier ends along the rotor periphery, and (d) optimization approaches were applied to smooth the torque. The synchronous reluctance machine is becoming of great interest in the last years, due to two key reasons: (i) the increase of rare earth permanent magnet cost and (ii) the increasing request of high-efficiency machines. Therefore, the reluctance motor and the ferrite permanent assisted reluctance motor are becoming competitors of both surface-mounted permanent magnet machines and induction machines in many applications. Such motors are also becoming particularly interesting when the control is based on the sensor-less rotor position detection. Even if there is a great interest in this kind of machines, there is a few work about the analytical design of their rotor, e.g. about how to select the end barrier angles, designing the iron ribs, and designing the permanent magnet robust towards the demagnetization. In the majority of the cases the reluctance machine is analyzed by using finite element analysis. The results are precise and useful for achieving a specific geometry to be prototyped, but they refer to that particular solution and they lose generality. In other words, it is difficult to find general rules to design reluctance machines, since the analysis approach is focused on a single objective. During the manufacturing process, there are some manufacturing imprecision, such as mass unbalance, bearing tolerance, shaft bow, and etc., cause eccentricity fault. Eccentricity may cause magnetic and dynamic problems with additional vibrations, noises, and torque pulsations. Although the eccentricity faults in induction and permanent magnet motors are extensively investigated, there are a few publications on synchronous reluctance machines with eccentricity. It is important to study the effect of rotor eccentricity on these machines because of their high anisotropy and critical iron parts in the rotor (iron ribs). For the aim of designing the iron ribs thicknesses, the unbalanced magnetic force acting on theses ribs should be accurately estimated. Main contribution of the thesis This thesis aims to give an useful analytical approach for reaching a preliminary geometry of both synchronous reluctance and permanent magnet assisted synchronous reluctance motors, as starting point for a successive optimization. For more accurate design of the rotor iron ribs, the electro-magnetic force acting on the rotor, in different rotor eccentricity cases, are analytically computed. In addition, a comparative studies (analytically and FE) between the synchronous reluctance, permanent magnet assisted, and surface mounted permanent magnet machines, in different eccentricity cases, is carried out. Therefore, this thesis is divided into four main parts. At the first part, an analytical model based on the magnetic equivalent lumped network of the reluctance motor is discussed. This model studies the magnetic performance of the concentric synchronous reluctance motor. Then, this analytical model is adopted in order to study the impact of different eccentricity scenarios (static and dynamic eccentricity) on the reluctance motor. Different stator windings configurations (distributed and concentrated windings) and different rotor geometries (symmetric and asymmetric rotor) are considered. After that, the eccentric synchronous reluctance machine is compared with the eccentric permanent magnet assisted synchronous reluctance machine. The impact of the barrier dimensions, the rotor geometry, and the permanent magnet type is highlighted in this comparison. Furthermore, an analytical comparison between the reluctance motor and the surface mounted permanent magnet motor is carried out in different cases of eccentricity. The axial non uniform displacement of the rotor axis from the stator axis, at one end and both ends of the axis, are involved in this analytical comparison. The second part aims to achieve more realistic estimation of the electromagnetic forces acting on the rotor by considering the effect of stator slots and the magnetic voltage drop due to the actual B-H curve of the motor iron. The analytical model is developed for both eccentric and concentric synchronous reluctance motor. Then, an experimental validation of the analytical and FE analysis is carried out. At the third part, an analytical approach for designing the permanent magnet of the permanent magnet assisted reluctance motor is proposed. The width and the thickness are selected so as to achieve the desired no-load air-gap flux density and resist the demagnetization under the desired loading conditions, respectively. Both complete and simplified analytical analyses are discussed. In addition, the analytical approach is presented in both cases of neglecting and considering the rotor iron ribs. Then, from the previously mentioned three parts of this thesis, a rapid multi-objectives analytical approach is proposed to achieve the initial design of the synchronous reluctance and permanent magnet assisted synchronous reluctance motors. Finally, at the fourth part, a graphical user interface application for concentric and eccentric synchronous reluctance motor is developed. This application estimates stator and rotor scalar magnetic potential, air-gap flux density, electromagnetic torque, magnetic force acting on the rotor. The input parameters of this application are - the geometrical data of the stator and rotor, - the electric loading (kA/m), the electric load angle in (electric degree), - the rotor geometry type, e.g., symmetric or asymmetric rotor geometry, - number of flux-barriers per rotor pole, - eccentricity type or no eccentricity, e.g., healthy case, - the eccentricity value. Then, the user can run the application to estimate the magnetic performance of both concentric and eccentric synchronous reluctance motor.
Negli ultimi vent'anni l'interesse per le macchine sincrone a riluttanza è notevolmente cresciuto. Lo sviluppo e la ricerca dedicata a questi motori, supportata dai diversi vantaggi che presentano rispetto ad altri tipi di macchine, ha permesso a questa tipologia di macchina di guadagnarsi uno quota di mercato in diverse applicazioni industriali. I motori a riluttanza offrono una piu alta densità di coppia rispetto ai motori asincroni. Tuttavia, se confrontati con i motori sincroni a magneti permanenti, essi presentano una densità di coppia ed una efficenza minori. Tale decremento delle prestazioni rispetto alle macchine a magneti permanenti è tuttavia compensato dalla complessiva riduzione del costo di costruzione del rotore. In aggiunta, essi presentano una struttura rotorica piu robusta delle macchine sincrone a magneti superficiali e consentono di ottenere un piu ampio range di funzionamento a potenza costante. I principali svantaggi delle macchine sincrone a riluttanza sono il basso fattore di potenza e le elevate oscillazioni di coppia. Il primo svantaggio, correlato alla assenza di alcun sistema di eccitazione sul rotore, viene normalmente mitigato attraverso l'introduzione di magneti permanenti all'interno delle barriere di flusso. Questo tipo di configurazione prende il nome di motore a riluttanza assistita da magnete permanente. Il secondo svantaggio, ossia l'eccessivo torque ripple, è dovuto all'elevato contenuto armonico della forza magnetomotrice che interagisce con l'anisotropia rotorica. Diversi approcci sono stati proposti in letteratura allo scopo di ridurre tali oscillazioni, tra i quali: (a) lo skewing del rotore, (b) barriere rotoriche geometricamente asimmetriche rispetto all'asse interpolare, (c) barriere rotoriche asimmetriche rispetto all'asse polare, (d) equa distribuzione delle barriere lungo la periferia del rotore, e (e) l'ottimizzazione della intera geometria delle barriere. Il grande interesse suscitato negli ultimi anni è dovuto principalmente a due motivi: (i) l'aumento di costo delle terre rare, utilizzate in magneti ad elevato contenuto energetico (NdFeB e SmCo); (ii) la crescente richiesta di macchine ad alta efficienza. Pertanto, il motore a riluttanza e il motore a riluttanza assistito da magneti permanenti stanno diventando concorrenti di entrambe le macchine a magneti permanenti e macchine a asincrone in molte applicazioni. Un altro vantaggio intrinseco delle macchine sincrone a riluttanza è che non inducono tensione a vuoto, quando il rotore è fermo, conseguentemente le correnti di corto circuito e coppie frenanti che si possono creare a causa dei guasti elettrici, sono trascurabili. Per quanto concerne l'aspetto controllistico è doveroso sottolineare il crescente interesse verso le le macchine sicrone a riluttanza. Tale interesse è sostanzialmente giustificato dalla naturale propensione della stessa macchina ad essere controllata senza alcun sensore di velocità. Sebbene vi sia un grande interesse per questo tipo di macchine, ci sono pochi lavori sulla progettazione analitica del loro rotore, ad esempio su come selezionare gli angoli di fine barriera, il dimensionamento dei ponticelli di ferro ed dettagli sulla progettazione robusta nei confronti della smagnetizzazione dei magneti permanenti. Nella maggior parte dei casi la macchina riluttanza viene analizzata mediante analisi agli elementi finiti. I risultati sono precisi e utili per realizzare una geometria specifica, ma si riferiscono ad una particolare soluzione perdendo generalità. In altre parole, è difficile trovare regole generali per progettare macchine a riluttanza. Per colmare questa lacuna, questa tesi si propone di fornire un approccio analitico utile alla determinazione di una geometria preliminare del motore, come punto di partenza per un'ottimizzazione successiva. La progettazione accurata dei ponticelli di ferro del rotore e gli effetti sulla forza elettromagnetica che agisce sul rotore con diversi gradi di eccentricità sono considerati. Questo lavoro di tesi è suddiviso in quattro parti principali. Un modello analitico basato sul circuito magnetico equivalente a parametri concentrati del motore a riluttanza viene presentato e discusso nella prima parte. Questo modello studia il rendimento magnetico del motore sincrono a riluttanza concentrica. Lo stesso modello analitico è utilizzato per lo studio di differenti casi di eccentricità ed il loro impatto sulle prestazioni del motore a riluttanza. Motori a riluttanza con diversi tipi di avvolgimenti statici e diverse geometrie di rotore, simmetriche ed asimmetriche, vengono considerate. Lo stesso metodo viene applicato a motori a riluttanza con magneti permanenti e confrontata con il motore a riluttanza eccentrico. I risultati prodotti dai modelli utilizzati vensono confrontati tramie simulazioni agli elementi finiti. Inoltre, un confronto analitico tra il motore a riluttanza e motore a magneti permanenti superficiali viene condotta in diversi casi di eccentricità. La seconda parte si propone di stimare in modo più accurato le forze elettromagnetiche agenti sul rotore, considerando l'effetto delle cave di statore e la caduta di tensione magnetica dovuta alla effettiva curva B-H del lamierino ferromagnetico. Il modello analitico è indicato per macchine con e senza presenza di eccentricità. Infine, misure sperimentali vengono condotte per validare la bonta' dei modelli analitici ed agli elementi finiti. Nella terza parte, si propone un approccio analitico per la progettazione del motore a riluttanza assistito da magneti permanenti. La larghezza e lo spessore dei magneti sono scelti in modo da realizzare la densità di flusso a vuoto al trafetto desiderata e resistere alla smagnetizzazione che si possono presentare in condizioni di sovraccarico. Infine, un rapido approccio analitico e multi-obiettivo è proposto per la progettazione preliminare di motori a riluttanza e motori a riluttanza assistiti. Nella quarta parte è stata sviluppata un'interfaccia utente grafica per l'analisi del motore a riluttanza. Questa applicazione stima i potenziali scalari magnetici di statore e rotore, la densità di flusso al traferro, la coppia elettromagnetica, la forza magnetica che agisce sul rotore. I parametri di ingresso di questa applicazione sono: - dati geometrici dello statore e del rotore, - carico elettrico (kA / m), e la sua fase (grado elettrico), - il tipo di geometria del rotore, ad esempio, simmetrico o asimmetrico (Macaone), - Numero di barriere di flusso per polo del rotore, - il tipo di eccentricità o nessuna eccentricità, per esempio, il caso con rotore concentrico, - il valore di eccentricità. Perciò, l'utente può usare l'applicazione per stimare le prestazioni della macchina.

As education systems, in particular Technology Education, adapt to new expectations for secondary students entering an uncertain workforce, the time is appropriate to investigate the need for school facilities to meet these present demands and those that continue to change curricula. This study has been conducted in order to determine the facility requirements for the delivery of the evolving technology/manual arts curriculum in Queensland. A set of validated design criteria for evaluating technology education and vocational education settings was developed and trialed to assist the designer of such facilities to meet the needs of this area on schools designed in different eras from the 1 960s to the present. A review of the published literature would indicate that little has been written on this aspect of facilities design. While related studies have been conducted in North America, they were not confined to the designing of the facilities and only had specific relevance in that country. An expert group consisting of prominent Queensland educators provided the impetus for developing the criteria which had been generated through a systematic search of the literature. The methodology utilised to involve the expert group was the Nominal Group Technique. After the criteria had been developed, they were validated by questionnaire through a 30% random sample of practicing heads of department across Queensland in both state and independent systems. A trial evaluation using current facilities was subsequently conducted to determine the effectiveness of the criteria in terms of teacher acceptability as well as establishing a pattern of needs for modification. Practitioners who use the facility for teaching technology education and/or vocational education could use the set of criteria to evaluate their facility in a similar manner to that of evaluating their students. Such evaluations could then become the basis for ffiture school planning and budgetary allocations as well as asset management of existing facilities. The study proved to be valuable as the validated criteria have the potential of being used as a tool by teachers to evaluate their facilities. At the systems level of operation, the criteria will provide assistance for designers, architects and teachers to prepare informal educational briefs. Such briefs would provide a consistent approach to the some times difficult task of clearly defining the function of a facility. The modem facility must meet the needs of current curriculum and be sufficiently flexible and adaptable to provide the educational requirements well into the twenty-first century. These developed criteria will greatly assist in this process.

As education systems, in particular Technology Education, adapt to new expectations for secondary students entering an uncertain workforce, the time is appropriate to investigate the need for school facilities to meet these present demands and those that continue to change curricula. This study has been conducted in order to determine the facility requirements for the delivery of the evolving technology/manual arts curriculum in Queensland. A set of validated design criteria for evaluating technology education and vocational education settings was developed and trialed to assist the designer of such facilities to meet the needs of this area on schools designed in different eras from the 1 960s to the present. A review of the published literature would indicate that little has been written on this aspect of facilities design. While related studies have been conducted in North America, they were not confined to the designing of the facilities and only had specific relevance in that country. An expert group consisting of prominent Queensland educators provided the impetus for developing the criteria which had been generated through a systematic search of the literature. The methodology utilised to involve the expert group was the Nominal Group Technique. After the criteria had been developed, they were validated by questionnaire through a 30% random sample of practicing heads of department across Queensland in both state and independent systems. A trial evaluation using current facilities was subsequently conducted to determine the effectiveness of the criteria in terms of teacher acceptability as well as establishing a pattern of needs for modification. Practitioners who use the facility for teaching technology education and/or vocational education could use the set of criteria to evaluate their facility in a similar manner to that of evaluating their students. Such evaluations could then become the basis for ffiture school planning and budgetary allocations as well as asset management of existing facilities. The study proved to be valuable as the validated criteria have the potential of being used as a tool by teachers to evaluate their facilities. At the systems level of operation, the criteria will provide assistance for designers, architects and teachers to prepare informal educational briefs. Such briefs would provide a consistent approach to the some times difficult task of clearly defining the function of a facility. The modem facility must meet the needs of current curriculum and be sufficiently flexible and adaptable to provide the educational requirements well into the twenty-first century. These developed criteria will greatly assist in this process.
Thesis (Masters)
Master of Philosophy (MPhil)
Center for Learning Research
Full Text

Education is commonly seen as an escape from poverty and a critical path to securing a better standard of living. This is especially relevant in the South African context, where the need is so great that in one instance people were trampled to death at the gates of a higher educational institution, whilst attempting to register for this opportunity. The root cause of this great need is a limited capacity and a demand, which outstrips the supply. This is not a problem specific to South Africa. It is however exaggerated in the South African context due to the country's lack of infrastructure and the opening of facilities to all people. Tertiary educational institutions are faced with ever-increasing applications for a limited number of available positions. This study focuses on a dataset from the Nelson Mandela Metropolitan University's Faculty of Engineering, the Built Environment and Information Technology - with the aim of establishing guidelines for the use of data modelling techniques to improve student admissions criteria. The importance of data preprocessing was highlighted and generalized linear regression, decision trees and neural networks were proposed and motivated for modelling. Experimentation was carried out, resulting in a number of recommended guidelines focusing on the tremendous value of feature engineering coupled with the use of generalized linear regression as a base line. Adding multiple models was highly recommended; since it allows for greater opportunities for added insight.

iv ABSTRACT URBAN CONVENTION HOTEL DESIGN CRITERIA AND A DESIGN PROPOSAL FOR ANKARA CASE Gizem, Balikç
ioglu M.Arch.
Department of Architecture Supervisor: Part-time Inst. ilhan Kural September, 2004 154 Pages The aim of this study is to define the design criteria for urban convention hotels based on national and international market trends. The second aim is to design an efficient, flexible, and valid convention hotel program for Ankara case based on this research. The existing hotel structures in Ankara are assumed to be insufficient to meet the convention requirements of international and national market needs. In the study, the space requirements of different markets and their program matrix reflected on major convention hotels in different continents are analyzed. The basic design criteria in terms of architectural space requirements and functional needs of the venues are defined. The economical, social and cultural impacts of the convention hotels in urban scale are listed in order to define a sustainable and efficient program in city scale. A feasibility study is done based on the space requirements, user groups and use frequencies of the convention venues in capital city. The second assumption of this study was that Ankara needed a 500 room convention hotel in order to accommodate the existing and future tourism stock of the city. A program based on the requirements of prior research is prepared and a design proposal is given for a site located in Ankara.

The present work focuses on CHCP systems, made up of gas engine as prime mover and absorption chiller as cooling device, combined with Evacuated Tube solar thermal Collectors (ETC). Such an energy system has provided the EURAC building with heating and cooling since 2002 and has been monitored since 2005. Thanks to the monitoring data, critical aspects have been highlighted concerning the size selection of some components, the overall layout and control strategy (Chapter 1). On the basis of this outcome, a procedure for optimal designing CHCP plus ETC systems has been defined and includes: 1. the layout and the control strategy selection (Chapter 2): beside the already mentioned basic components, the layout also includes a biomass boiler, as a further renewable heat source, and a compression chiller, as a cooling back up device; 2. the definition of a sizing procedure for each component of the layout (Chapter 3): this procedure is based on a spreadsheet which requires the heating and cooling demand of the building and a first sizes selection concerning the absorption chiller, the cogenerator and the solar collectors in order to output the sizes of all the left plant components; 3. the development of a TRNSYS deck which simulates the designed plant at off design conditions (Chapter 5): to this end, two new models have been developed in MATLAB respectively for a gas engine based cogeneration unit and a biomass boiler (Chapter 4). Such design procedure has been applied in order to select the sizes suitable to match the EURAC heating and cooling demand. On this subject, by repeating the sizing procedure with different initial sizes of the major plants component and by considering different control strategies, various configurations have been output. Such configurations have been simulated in TRNSYS to calculate the Primary Energy Consumptions (PEC), the Operation Costs (OC) and the CO2 emissions which can be saved by the examined system with respect to a conventional system. By comparing the savings turned out of all the simulations, the optimal size of the cogeneration unit, the biomass boiler, the absorption and the compression chiller have been identified. The obtained results have also been discussed from the point of view of the Discounted Pay Back Period (Chapter 6).

As a graphic designer, my goal is to clearly express my clients' message to their intended audience. Based on the diversity of my clients and their products and services, finding a consistent style in my projects might be difficult, although there are usually some typical traits. With examples of my work and dialogue from leaders in the graphic design industry, I intend to point out a common thread that runs through all successful design projects, regardless of the projects' designer, era, or individual design elements (e.g., typography, copywriting, color, layout, imagery). Success comes from graphic design's ability to gain attention and encourage a response.

In this dissertation, the major objective is to compare 3 and 4 factor response surface designs in a spherical design region by studying design optimality criteria (D, A, G, and IV-criteria) over sets of reduced models. Hence, theoretical and computational details of evaluating optimality criteria for reduced models for response surface designs in a spherical design region have been described. Specifically, robustness results of the spherical response surface designs and the comparison of design optimality criteria of the response surface designs across the full second-order model and sets of reduced models for 3 and 4 design variables based on the four optimality criteria (D, A, G, and IV-criteria) are presented. Also, new types of D, A, G, and IV optimality criteria for response surface designs in a spherical design region are developed by using prior probability assignment to model effects (for some specified values of pl, pq, p 1, and p2). The four new D, A, G , and IV optimality criteria will be referred to as weighted design optimality criteria. The weighted design optimality criteria of the response surface designs across the weak heredity and strong heredity reduced models for 3 and 4 design variables are evaluated.

Spatial Arch Bridges (SABs) are defined as bridges in which vertical deck loads produce bending moments and shear forces not contained in the arch plane due to their geometrical and structural configuration. Moreover, the arch itself may not be contained in a plane. A wide compilation of examples of this bridge type has been made. Different benchmarks have been developed to assure the validity of the analysis methods employed in the present research. An in-depth study of planar and non-planar Inferior Deck Arch Bridges With Imposed Curvature (IDABWIC) has been carried out. In this type of spatial arch bridges the arch and the deck centroid lines are both contained in the same vertical cylinder. The aim of the study is to propose the most appropriate design for controlling the out-of-plane response. In order to understand the behaviour of these arches, different frame 3D models have been developed and analyzed with commercial software. The arch definition, the deck and arch plan curvature, the arch sag and cross-sections rigidity of arch, deck and hangers, as well as arch cross-section area and different hanger/deck and hanger/arch connection types, have been studied as variables under both symmetrical and asymmetrical vertical loading. Both flexible and rigid hangers have been analysed. A thorough study for different geometries and boundary conditions at deck abutments of superior deck true SABs under vertical loading and temperature variation has been conducted. The purpose of the study is to understand the structural behaviour of different geometries of this bridge type and to establish the best boundary conditions at abutments in each case. Vertical planar arch bridges with a curved superior deck are spatial arch bridges (SABs) with a very characteristic structural behaviour and many interesting structural and aesthetic possibilities. A thorough parametric analysis has been conducted in order to establish efficient values of different parameters for this bridge type according to different criteria. The objective is to minimize the total amount of structural materials. An appropriate range of values for the different parameters (arch/deck eccentricity, arch rise, arch/deck vertical distance, inclination of struts and the cross-section of the different elements) is given and it is established which parameters are key to the bridge behaviour. The changes in the structural behaviour according to the different parameters are explained. The stability of SABs with a curved deck is studied and compared with that of planar vertical arch bridges with a straight deck. For different models of this bridge type geometrically non-linear analyses with and without imperfections have been conducted. The sensibility to imperfections has also been studied, considering the coded imperfections based on the behaviour of planar vertical arch bridges. Most SABs are footbridges. Therefore, the dynamic behaviour of this bridge type is an important aspect to be considered. The dynamic behavior of this type of footbridges has been hence also conducted for a SAB example with curved superior deck.
Definimos como Puentes Arco Espaciales (PARES) todo puente arco en el que, por su configuración geométrica y estructural, las cargas gravitatorias generan flexiones y cortantes no contenidos en el plano del arco. Además, el propio arco puede no estar contenido en un plano. Se ha llevado a cabo una amplia recopilación de realizaciones de este tipo de puentes. se han desarrollado varios benchmarks para asegurar la validez de los métodos de análisis empleados en la presente investigación. Se ha realizado un amplio estudio de los Puentes Arco de Tablero Inferior con Curvatura Impuesta planos y no planos. En este tipo de puentes arco espaciales el eje del arco y del tablero están contenidos en el mismo cilindro vertical. El objetivo del estudio es proponer el diseño más apropiado para controlar la respuesta fuera del plano del arco. Con el fin de entender el comportamiento de estos arcos, se han desarrollado y analizado diferentes modelos de barras en 3D marco con un software comercial. La definición del arco, de la curvatura del tablero y de la curvatura del arco en planta, la flecha horizontal del arco ceder y la rigidez de las secciones transversales del arco, del tablero y de las péndolas, así como el área de la sección transversal del arco y distintos tipos de conexión péndolas/ tablero y péndolas/arco, se han estudiado como variables bajo tanto carga vertical simétrica como asimétrica en tablero. Se ha considerado el uso tanto de péndolas flexibles como rígidas. Se han estudiado diferentes geometrías y condiciones de contorno en los estribos del tablero para PARES de tablero superior bajo carga vertical y variación de temperatura. El propósito del estudio es entender el comportamiento estructural de distintas geometrías de este tipo puentes y establecer las condiciones de contorno más convenientes en estribos de tablero para cada caso. Los puentes con un arco plano vertical con tablero superior curvo son PARES con un comportamiento estructural muy característico e interesantes posibilidades estructurales y estéticas. Se ha realizado un amplio análisis paramétrico con el fin de establecer valores eficientes para diferentes parámetros en este tipo de puentes de acuerdo con distintos criterios. El objetivo es minimizar la cantidad total de materiales estructurales empleados. Se da un rango adecuado de los valores de diferentes parámetros (excentricidad arco/ tablero, flecha del arco, distancia vertical arco/tablero, inclinación de pilas y la sección transversal de los diferentes elementos) y se establece qué parámetros son fundamentales para el comportamiento de estos puentes. Se explica la influencia de la variación de los distintos parámetros estudiados en la respuesta estructural. La estabilidad de los PARES con tablero se estudia y compara con la de los puentes en arco planos verticales con tablero recto. Se ha llevado a cabo un análisis no lineal geométrico con y sin imperfecciones para diferentes modelos de este tipo puentes. La sensibilidad a las imperfecciones también ha sido estudiada, teniendo en cuenta las imperfecciones estipuladas en los Eurocódigos, basados en el comportamiento de los puentes en arco planos verticales con tablero recto. La mayoría de los PARES son pasarelas. Por lo tanto, el comportamiento dinámico de este tipo puente es un aspecto importante a considerar. Así pues, se ha llevado a cabo un análisis dinámico para un ejemplo PARES con el tablero superior curvo

This work develops a backfill design procedure aimed to facilitate the optimization of an available mine material in order to meet target objectives in a particular mining role. This required the compilation and analysis of data on fill usage, established design procedures, physical and geomechanical properties, testing techniques and procedures, as well as behavioural modelling methods.
A backfill classification system is proposed based upon size distribution. A series of design equations are presented which relate to this system. These equations represent the means by which backfill geomechanical behaviour can be related to physical properties. This is considered to be fundamental to an effective backfill design procedure. Derivation of the equations has been based upon analysis of data from a program of laboratory and in situ testing conducted in ten operating Canadian mines by the author, together with other published work.
The in situ testing required the development of a pressuremeter testing procedure novel to underground mining. The theoretical basis for the employment of pressuremeter data has been examined and behavioral equations have been developed to describe the deformation and stress history during a backfill material test. In addition two new equations have been developed for the analysis of pressuremeter data. The in situ data collected has been correlated with laboratory derived geomechanical data for the same backfill materials.
The geomechanical properties associated with the proposed backfill classifications have also been related to their influence on backfill behaviour in three mine backfill roles: free standing stability during pillar recovery in bulk mining methods; dynamic interaction with stope walls in rockburst prone ground; and ability to reduce stresses in highly stressed rock masses. This work has been based on new and established modelling methods and aims to provide insight into the effectiveness of the backfill classes in these roles of growing practical significance.

Public Transit Information System is an online transportation system providing integrated transit journey planning solutions to the general public. Generally, the system requires users to input their places of departure and arrival as well as some preferences such as the shortest or cheapest path. The system will then generate the results with transit schedule, route, fare and so forth. Since the system is designated for public usage, it is important that the system not only meets the needs of its users, but also is easily operated by the general public with different level of computer skills. Thus, this paper explores the design criteria of public transit information system by reviewing the development of user interface design from previous research and comparing the user interfaces of the public transit information systems of Hong Kong, Singapore and Vancouver. This paper also studies the transit systems of these three places and thereby concludes that the diverse and complex transit network of Hong Kong makes it difficult in developing such a system. This paper concludes that aesthetics, consistency and effective error management are the technical design criteria that can improve the usability of public transport information systems. In addition, technicians should also consider the social aspects, such as computer literacy and the computer systems when designing products for the public.
published_or_final_version
Transport Policy and Planning
Master
Master of Arts in Transport Policy and Planning

Mycket av den forskning som finns om typografi är gjord för nästan hundra år sen. Sen dess har mycket facklitteratur presenterats i ämnet. I dagens medielandskap är det många tidskrifter som behöver förändring för att hålla sig aktuella. Syftet med detta examensarbete är att undersöka vad det finns för typografiska kriterier vid redaktionell redesign i den svenska tidskriftsbranschen. Syftet uppnåddes genom jämförelse av insamlad data från intervjuer, empiri från facklitteratur och teorier från forskning. Fem semistrukturerade telefonintervjuer genomfördes med representanter från branschen. Analysen ledde till olika slutsatser med olika mycket stöd från forskning och facklitteratur. Språkstöd och valmöjligheter för typsnitt blev generaliserbara kriterier då behovet för olika fonter beskrivs som viktigt av alla parter. Teckengrad ska inte generaliseras såsom facklitteraturen visar, då det ansågs som något relativt inom både forskning och bransch. Negativ text och radlängd visade sig vara typografiska aspekter som branschen valde att inte ta hänsyn till trots tydliga regler i forskning och facklitteratur. Vid val av typografi förhöll sig branschen ofta mer till känsla och ett typsnitts karaktär än till krav på funktionalitet. Författarna kom också fram till att forskning och facklitteratur menar att redesign bör prioriteras, men att detta inte alltid genomfördes då kundens önskemål i slutändan var det som avgjorde vad som skulle göras.

The background for this thesis is based on the assumption that the success of solar buildings relies on the assessment and integration of all the different design objectives, called criteria. These criteria are often quite complicated to deal with (e.g. environmental loading) and may be conflicting. The different design issues and the many different available energy technologies call for different areas of expertise to be involved in the design of solar buildings. This makes it difficult to evaluate the overall “goodness” of a proposed design solution. Also, the communication between design professionals and the client becomes complicated.

The goal of this work was therefore to produce a means for the design team and clients to be able to better understand and handle holistic solar design. A first hypothesis was that a structured approach for evaluating design alternatives might be a means to this end.

In order to specify an approach that would fit into the building design process, an analysis of design process theory and building design practice was carried out (chapter 2). Also, special solar design issues were investigated. This analysis resulted in the following conclusions:

· Most building design processes start out with no clearly defined goals or criteria of success. The design criteria are refined and discovered through evaluation and feedback on alternative design proposals.

· Design involves a lot of subjective value judgements, and decisions are often based on experience, “gut feeling”, or intuition. Design options are evaluated based on quantitative and qualitative performance measures. There exists no objective optimal design solution.

· It is possible to identify some main activities that are common to most design processes. These are categorized into 4 main tasks: problem formulation, generation of alternatives, performance prediction and evaluation. The activities are very much overlapping and dependent on each other.

· Decision-making in design happens mainly through evaluation of proposed design solutions.

The successful energy design of buildings requires that special attention be paid to the conceptual stage. However, it is a difficult task to find the most promising design alternatives satisfying several conflicting criteria. This thesis presents a simple multi-criteria decisions analysis method that could assist designers in green building design. Variables in the model include those alternatives that are common options when a residential building is to be constructed. The individual components that are considered are the building envelope, heating, ventilation and air conditioning (HVAC) system, service water heating, power and lighting. The key actors, objectives and methodology of multi-criteria decisions analysis are presented and finally a case study for a residential building in Athens is performed. The criteria by which to evaluate each building component of the newly built construction were identified by the decision-makers. Subsequently, decision frameworks for the selection of roof, walls, windows, heating system, energy source for heating system, power source, lighting and service water heating system were built. The method is followed step-by-step to conclude on the optimal building components based on their score. Due to the equal scoring of the windows and an inapplicable combination of electric underfloor heating with air-to-water heat pump, the method is characterized by low accuracy. The fact that the building components have been treated individually sets the method as a basic one and indicates that a more complex one should be preferred when more trustworthy results are needed.

In several types of embedded systems the applications are deployed both as software and as hardware components. For such systems, the partitioning decision is highly important since the implementation in software or hardware heavily influences the system properties. In the industry, it is rather common practice to take deployment decisions in an early stage of the design phase and based on a limited number of aspects. Often such decisions are taken based on hardware and software designers‟ expertise and do not account the requirements of the entire system and the project and business development constraints. This approach leads to several disadvantages such as redesign, interruption, etc. In this scenario, we see the need of approaching the partitioning process from a multiple decision perspective. As a consequence, we start by presenting an analysis of the most important and popular Multiple Criteria Decision Analysis (MCDA) methods and tools. We also identify the key requirements on the partitioning process. Subsequently, we evaluate all of the MCDA methods and tools with respect to the key partitioning requirements. By using the key partitioning requirements the methods and tools that the best suits the partitioning are selected. Finally, we propose two MCDA-based partitioning processes and validate their feasibility thorough an industrial case study.

This thesis deals with the non-linear dynamic time history analysis of a certain type of medium- and high-rise concentric braced frame designed according to the new National Building Code of Canada (1990) and CAN/CSA-S16.1-M89. The program DRAIN-2D was used to carry out the earthquake simulations of this structure. A number of recorded earthquakes was selected as the input of ground motions.
A preliminary statistical study is attempted on the structural response to the ground motions.
The design procedures proposed by the new design codes are evaluated. Some provisions of Clause 27 of the CAN/CSA-S16.1-M89 have been found inadequate in the light of the analysis described. Some revised procedures are proposed and then evaluated against those currently in use. The results are shown to provide improved designs.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1985.
MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.
Bibliography: leaves 373-379.
by Yusuke Honjo.
Ph.D.

The NASA Performance Adaptive Aeroelastic Wing (PAAW) project goals include significant reductions in fuel burn, emissions, and noise via efficient aeroelastic design and improvements in propulsion systems. As modern transport airplane designs become increasingly lightweight and incorporate high aspect-ratio wings, aeroservoelastic effects gain prominence in modeling and design considerations. As a result, the influence of the flight dynamics and controls on the optimal structural and aerodynamic design needs to be captured in the design process. There is an increasing interest in more integrated aircraft multidisciplinary design optimization (MDAO) processes that can bring flight control design into the early stage of an aircraft design cycle. So, in this thesis different flight dynamics modeling methodologies are presented that can be integrated within the MDAO framework. MDAO studies are conducted to maximize the controllability and observability of a UAV type aircraft using curvilinear SpaRibs and straight spars and ribs as the internal structural layout. The impulse residues and controllability Gramians are used as surrogates for the control objectives in the MDAO to maximize the controllability and observability of the aircraft. The optimal control designs are compared with those obtained using weight minimization as the design objective. It is found that using the aforementioned control objectives, the resulting aircraft design is more controllable and can be used to expand the flight envelope by up to 50% as compared to the weight minimized design.
Doctor of Philosophy
Over the last two decades, several attempts have been made towards multidisciplinary design analysis and optimization (MDAO) of flexible wings by integrating flight control laws in the wing design so that the aircraft will have sufficient control authority across different flying conditions. However, most of the studies have been restricted to the wing design only using a predefined control architecture approach, which would be very difficult to implement at the conceptual design stage. There is a need for an approach that would be faster and more practical. Including control surface and control law designs at the conceptual design stage is becoming increasingly important, due to the complexity of both the aircraft control laws and that of the actuation and sensing, and the enhanced wing flexibility of future transport aircraft. A key question that arises is, can one design an aircraft that is more controllable and observable? So, in this thesis, a more fundamental approach, in which the internal structural layout of the aircraft is optimized to design an aircraft that is more controllable, is presented and implemented. The approach uses the fundamentals of linear systems theory for maximizing the controllability and observability of the aircraft using an MDAO framework.

The Mine Improvement and New Emergency Response (MINER) Act of 2006 was enacted in response to several coal mining accidents that occurred in the beginning of 2006. The MINER Act does not just require underground mines to integrate wireless communication and tracking systems, but aims to overall enhance health and safety in mining at both surface and underground operations. In 2006, the underground communication technologies available to the mining industry had inherent problems that limited communication capabilities. Since the passage of the MINER Act, there have been several developing applications for underground wireless communications. Underground wireless communications allow signals to propagate and take multiple paths to destinations providing a survivable, redundant, and adaptable means of communication and tracking. An underground wireless communications allow underground and surface personnel to directly correspond to one another without being as restricted as hardwired systems. Communication systems also allow miners to be tracked underground to provide a real-time or last known post-accident position, and ensure a more efficient rescue operation. In order to increase the overall efficiency of developing communication systems there is a need for modeling of wireless signal propagation in underground mines. Research, modeling, and analysis of wireless signal propagation in underground mines ongoing and developing with underground communications systems as the systems progress. The work on this project is based upon the Accolade system from L-3 Communications Global Security and Engineering Solutions but applies to all underground wireless mesh systems currently available. A general approach is taken to solving underground wireless communications networks to allow the design criteria to be adaptable to other communication systems belong the Accolade system. The data is based upon measurements and field work that took place July 2007 through December 2008 in International Coal Group's Sentinel Mine in Philippi, West Virginia. Comms, a computer method developed at the Virginia Center for Coal and Energy Research at Virginia Tech, allows underground mine communication networks to be solved and analyzed. Comms was developed to solve and analyze underground wireless communication networks. The method which Comms solves communication networks is not mine specific and may be adapted to predict the performance of a system(s) in another mine. The developed model discussed in Chapters 3 and 4 highlights the general signal loss parameters that are encountered by wireless signals in a mine. The model predicted the signal strength observed when encountering those categorized signal losses within 16 percent of the data measured during a mine survey. The model has been developed in a general manner to allow future investigation and pinpointing of additional interferences that occur within the underground environment. Wireless communications have proven to be the way of the future and will continue to be integrated into underground coal mines as mandated by the MINER Act. Wireless communications systems are a redundant and survivable means of communication that will be utilized in not only emergency and rescue efforts but daily operational communication as well.
Master of Science