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Agarwal, Pranab. "Conceptual design of long-span trusses using multi-stage heuristics". Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969.1/3863.
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A hybrid method that addresses the design and optimization of long-span steel trusses is presented. By utilizing advancements in present day computing and biologically inspired analysis and design, an effort has been made to automate the process of evolving optimal trusses in an unstructured problem domain. Topology, geometry and sizing optimization of trusses are simultaneously addressed using a three stage methodology. Multi-objective genetic algorithms are used to optimize the member section sizes of truss topologies and geometries. Converting constraints into additional objectives provides a robust algorithm that results in improved convergence to the pareto-optimal set of solutions. In addition, the pareto-curve plotted based on how well the different objectives are satisfied helps in identifying the trade-offs that exist between these objectives, while also providing an efficient way to rank the population of solutions during the search process. A comparison study between multi-objective genetic algorithms, simulated annealing, and reactive taboo search is conducted to evaluate the efficiency of each method with relation to its overall performance, computational expense, sensitivity to initial parameter settings, and repeatability of finding near-global optimal designs. The benefit of using a three stage approach, and also implementing the entire model on parallel computers, is the high level of computational efficiency that is obtained for the entire process and the near-optimal solutions obtained. The overall efficiency and effectiveness of this method has been established by comparing the truss design results obtained using this method on bridge and roof truss benchmark problems with truss designs obtained by other researchers. One of the salient features of thisresearch is the large number of optimal trusses that are produced as the final result. The range of designs available provides the user with the flexibility to select the truss design that best matches their design requirements. By supporting human-computer interactions between these stages, the program also incorporates subjective aesthetic criteria, which assist in producing final designs in consonance with the user's requirements.
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Sigvant, John. "Conceptual Design of an Air- launched Multi-stage Launch Vehicle". Thesis, KTH, Fysik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-284355.
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In the present thesis, the objective was to find the maximum amount of payload mass that can be put into a 500 km polar orbit by a 1400 kg air-launched multi-stage rocket launched from a fighter jet platform. To fulfill the objective an algorithm incorporating several modules was developed. The modules performed calculations based on theoretical models and literature values to arrive at optimal design variables. From the design the maximum payload mass was able to be derived and it was concluded that a three-stage launch vehicle was able to deliver a 22.0 kg payload to the desired orbit.I den här avhandlingen var syftet att hitta den maximala mängden nyttolastmassa som kan transporteras av en 1400 kg flerstegsraket uppskjuten från luften till en 500 km polär bana. För att uppfylla målet utvecklades en algoritm med flera moduler. Modulerna utförde beräkningar baserade på teoretiska modeller och litteraturvärden för att komma fram till optimala designvariabler. Från konstruktionen kunde den maximala nyttolastmassan härledas och det konstaterades att en trestegsraket kunde leverera en nyttolast på 22.0 kg till den önskade omloppsbanan.
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Ballard, Claire. "Conceptual lay-out of small launcher". Thesis, KTH, Energiteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-95206.
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The objective of this diploma thesis is to perform a conceptual lay-out of a small launcher. Re- quirements have been defined in order to realize this first preliminary study and design of a small launcher. In that frame, a MATLAB code has been written in order to simulate the rocket tra- jectories. An optimization program on launcher staging has been written as well. To validate this code, the VEGA and Ariane 5 launchers have been used. Then from studies on existing launchers, simulations have been performed in order to find an optimum small launcher and later on to design more precisely the small launcher. As a requirement an upper stage has been newly designed for the purpose of the study. At the end, two small launchers have been considered: a three-stage launcher using the Zefiro 23 as a first stage, the Zefiro 9 as a second stage, and an upper stage using a 3kN thrust engine; a two-stage launcher using the Zenit booster engine in the first stage, and an upper stage using a 22kN thrust engine.
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Mustafa, Janan Abdulsattar. "Computer-based sketching and the productivity of the conceptual stage of design". Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/8858.
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Many designers find computer-based tools are not as effective during the early stages of design as manual sketching. However, to abandon the computer in these conceptual stages denies designers the computer‟s capability to translate and supplement imaginative design thinking. Recent design studies address conceptual design. What is the impact of computer-based drawing and sketching on designers‟ cognition and productive reasoning? This research focuses on the relationship between the characteristics of sketching using the drawing environment of the computer and the productivity of the conceptual design phase. I provide a theoretical framework that identifies and clarifies both sketching and productivity. Previous specialized studies are selective and sometimes only descriptive in defining this relationship. A review of these studies reveals a gap in our understanding of those aspects of sketching that relate to visualization, imagination and the generation of design ideas. The thesis addresses three objectives: (i) to build a comprehensive theoretical framework that on one hand defines the characteristics of sketching that might affect the generation of design ideas, and on the other hand defines the productivity of conceptual design and its indicators; (ii) to apply this framework in a practical study; and (iii) to extract implications for the relationship. To address the problem of computer-based sketching, I indentify the continuity within the dynamic field of images usually generated while designers sketch as the most effective characteristic of the computer sketching process. I establish a measure of continuity defined by (i) the degree of ease in projecting design images, (ii) the degree of continuity of displaying images due to changing the status of the design objects and due to navigation around the objects, (iii) the degree of provision of a holistic view (i.e., the total view of the design objects on the computer screen). Then I define productivity within this framework in terms of the cognitive operations of dialogical reinterpretation. When sketching, designers seem to perform key operations such as interpreting, reframing and restructuring. I present the case that a process rich with these cognitive operations is productive. The study makes use of the fields of free hand sketching, literature, cognitive psychology and Gestalt theory. Four indicators emerge from this study: the occurrence of pattern discovery, conceptual reinterpretation, alternation of thinking, and restructuring. I identify key variables that define the degree of continuity of the dynamic field of images which relate to designer‟s performance to verify their relationship with productivity. I study ten design participants who are given a design task that involves sketching with various CAD systems. The study involves 21 hours of recorded video analyzed using a method adapted from Goldschmidt's “linkography” tool for representing design protocols. I identify where patterns of relationships between variables exist, and where they do not apply. Not all the selected variables of continuity of the dynamic field of images, nor all the indicators of productivity in the conceptual design phase, support these patterns of relationships. This indicates that there is a special group of characteristics of sketching that maintain the pace of continuity within the dynamic field of images can improve the productivity in the conceptual phase.
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Lejon, Alexander. "Creation and Validation of Early Stage Conceptual Design Methodology for Blended WingBody Aircraft". Thesis, KTH, Flygdynamik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-261700.
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The current design paradigm for developing tube-and-wing style aircraft has been well documented in literature. This research attempts to develop and val-idate a similar design methodology to what is presently utilized for tube-and-wing based aircraft, but has so far not been successfully implemented for the blended wing-body. This construction has no clear distinction between the lift generating surfaces and the cargo carrying structure. The methodology that was developed included the concatenation and validation of low-fidelity, low speed and low complexity aerodynamic models in order to allow for quick and simple analysis of a large number of possible geometries. This enables the user eÿciently determine the most promising candidate geometries for further study and/or development. Known issues with the low velocity and low com-plexity aerodynamic models include the absence of shock wave modelling, an important part in determining the aerodynamic performance of a lift generat-ing surface. The result of this work is the creation and documentation of a procedure for early-stage design of a blended wing-body airframe. However, due to convergence issues with the high-fidelity CFD solver, the methodology could not been validated for transonic flow. It can thus be only considered valid for flow velocities for which the Prandtl-Glauert correction is valid.Den befintliga konstruktionsmetodiken för utveckling och design av flygfarkoster är väl dokumenterad i tidigare publicerad litteratur. Detta arbete ämmar utveckla och validera en liknande metodologi som redan existerar för de väl etablerade flygplansgeometrier som baseras på cylinder/vingar-principen. Metoden som utvecklades inkluderade sammansättaning och validering av tidigare existerande lågupplösta samt lågkomplexa aerodynamiska modeller avsedda för beräkning av flödesekvationer för inkompressibel, friktionsfri och stationär strömning. Detta var avsett att möjliggöra ögonblicksvalidering av en föreslagen sammansmält kropp/vinge-geometri med speciell fokus på vissa prestationsbaserade nyckeltal. För cylinder/vinge-geometrier är dessa lågupplösta metoder i litteraturen väletablerat inexakta på grund av en avsaknad av stötvågsmodellering, men då stora delar av de lyftkraftsgenererande ytorna för-ändrats på en sammansmält kropp/vinge är inte nödvändigtvis detta sant för den typen av flygplan också. Då de högupplösta, mer komplexa höghastighetssimuleringarna inte konvergerade inom den utsatta tiden kan den föreslagna metodiken endast anses giltig för det intervall av flödeshastighet vari PrandtlGlauerts korrektionsfaktor stämmer väl överens med verkligheten.
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Al-Dosary, Bashar. "Integrating 3D-CAD and Cost Estimating at the Conceptual Design Stage of Bridge Project". Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32570.
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Bridge Information Modeling (BrIM), as a concept, has been introduced to enhance the procedures of the whole phases of a bridge life-cycle starting with concept and design, through construction and operation, and ending with maintenance and rehabilitation. Integrating BrIM and design tools will help improve the methods used in designing and constructing bridge projects at early stages taking into considerations their cost and time constraints. The main objective of this research is to develop an integrated model that helps owners, designers and construction managers visualize bridge projects in a 3D mode and accordingly automate the process of generating preliminary cost estimates during the conceptual design stage. To achieve the above mentioned objective, a proposed methodology will be applied where all the aspects needed to develop an efficiently integrated model are realized. Thus, this research describes the proposed methodology that incorporates three modules, which are the core of the integrated model. These modules are: a knowledge based system module, which is used to generate conceptual dimensions and parameters depending on algorithmic and heuristic knowledge gathered from codes, guidelines and design experts; a conceptual cost estimation module, which is used to generate conceptual cost estimate based on the results of the first module; and a 3DCAD module, which is integrated with the previous modules where users will visualize the proposed bridge in 3D based on the results of the knowledge based module. The successful development of the model would help owners and investors identify the cost and visualize the proposed projects at the early stages of the project life, so they have an idea of the budget required and the aesthetics of the proposed projects. The integrated model is validated through an actual case project to test its workability and output.
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Osti, Francesco. "Tecniche innovative di modellazione diretta nell'early stage design". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016.
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Partendo da un’analisi dei problemi che si incontrano nella fase di conceptual design, si presentano le diverse tecniche di modellazione tridimensionale, con particolare attenzione al metodo subdivision e agli algoritmi che lo governano (Chaikin, Doo – Sabin). Vengono poi proposti alcuni esempi applicativi della modellazione free form e skeleton, con una successiva comparazione, sugli stessi modelli, delle sequenze e operazioni necessarie con le tradizionali tecniche di modellazione parametrica. Si riporta un esempio dell’utilizzo del software IronCAD, il primo software a unire la modellazione parametrica e diretta. Si descrivono le limitazioni della modellazione parametrica e di quella history free nella fase concettuale di un progetto, per arrivare a definire le caratteristiche della hybrid modeling, nuovo approccio alla modellazione. Si presenta brevemente il prototipo, in fase di sviluppo, che tenta di applicare concretamente i concetti dell’hybrid modeling e che vuole essere la base di partenza per una nuova generazione di softwares CAD. Infine si presenta la possibilità di ottenere simulazioni real time su modelli che subiscono modifiche topologiche. La simulazione real time è permessa dalla ridefinizione in forma parametrica del problema lineare elastico che viene successivamente risolto mediante l’applicazione congiunta delle R – Functions e del metodo PGD. Seguono esempi di simulazione real time.
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Babak, I., i E. Druzhinin. "Computer-Aided Design System Application at Conceptual Stage of Unmanned Air Vehicle Life Cycle". Thesis, Sumy State University, 2016. http://essuir.sumdu.edu.ua/handle/123456789/47035.
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The steps of computer-aided design system application at conceptual stage of unmanned air vehicle life cycle are considered. Sequential and iterative approach to an aircraft design process are compared.
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Hosseinipour, Milad. "Design and Development of an Intra-Ventricular Assistive Device For End Stage Congestive Heart Failure Patients: Conceptual Design". University of Toledo / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1372726495.
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Rivera, Rosario. "An empirical study of the conceptual stage of design in mechanical engineering and its implications for CAD". Thesis, University of Wolverhampton, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309581.
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Löfgren, Maria, i Hiba Seid. "Cost and Weight Estimations at an Early Conceptual Design stage : Case study with gearbox manufacturing". Thesis, KTH, Industriell produktion, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-217864.
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Jalaei, Farzad. "Integrate Building Information Modeling (BIM) and Sustainable Design at the Conceptual Stage of Building Projects". Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32536.
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Lately the construction industry has become more interested in designing and constructing environmentally friendly buildings (e.g. sustainable buildings) that can provide both high performance and monetary savings. Analyzing various parameters during sustainable design such as Life Cycle Assessment (LCA) and energy consumption, lighting simulation, green building rating system criteria and associated cost of building components at the conceptual design stage is very useful for designers needing to make decisions related to the selection of optimum design alternatives. Building Information Modeling (BIM) offers designers the ability to assess different design options and to select vital energy strategies and systems at the conceptual stage of proposed buildings.
This thesis describes a methodology to implement sustainable design for proposed buildings at their conceptual stage. The proposed methodology is to be implemented through the design and development of a model that simplifies the process of designing sustainable buildings, evaluating their Environmental Impacts (EI), assessing their operational and embodied energy and listing their potential accumulated certification points in an integrated environment. Therefore, a Decision Support System (DSS) is developed by using Multiple Criteria Decision Making (MCDM) techniques to help design team decides and selects the best type of sustainable building components and design families for proposed projects based on three main criteria (i.e. Environmental, Economical factor «cost efficiency » and Social wellbeing) in an attempt to identify the influence of design variations on the sustainable performance of the whole building.
The DSS outcomes are incorporated in an integrated model capable of guiding users when performing sustainable design for building projects. The proposed methodology contains five modules: 1) Database Management System (DBMS), 2) Energy and lighting analysis, 3) Life Cycle Assessment (LCA), 4) LEED and 5) Life Cycle Cost (LCC). To improve the workability of the proposed model, a use case of abovementioned modules are going to be created as plug-ins in BIM tool.
The successful implementation of such a methodology represents a significant advancement in the ability to attain sustainable design of a building during the early stages, to evaluate its EI, and to list its potentially earned certification points and associated soft costs.
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Osti, Francesco <1989>. "Direct modeling techniques in the conceptual design stage in immersive environments for DfA&D". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amsdottorato.unibo.it/9173/3/Direct%20modeling%20techniques%20in%20the%20conceptual%20design%20stage%20in%20immersive%20environments%20for%20DfA%26D.pdf.
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Due to the fast – growing competition of the mass – products markets, companies are looking for new technologies to maximize productivity and minimize time and costs. In the perspective of Computer Aided Process Planning (CAPP), companies want to optimize fixture design and assembly planning for different goals. To meet these demands, the designers' interest in Design for Assembly and Disassembly is growing considerably and is increasingly being integrated into the CAPP. The work described in this thesis aims to exploit immersive technologies to support the design of mating elements and assembly / disassembly, by developing a data exchange flow between the immersive environment and the modeling environment that provides the high – level modeling rules, both for modeling features and for assembly relationships. The main objective of the research is to develop the capability to model and execute simple coupling commands in a virtual environment by using fast direct modeling commands. With this tool the designer can model the coupling elements, position them and modify their layout. Thanks to the physical engine embedded in the scene editor software, it is possible to take into consideration physical laws such as gravity and collision between elements. A library of predefined assembly features has been developed through the use of an external modeling engine and put into communication with the immersive interaction environment. Subsequently, the research involved the study of immersive technologies for workforce development and training of workers. The research on immersive training involved industrial case studies, such as the projection of the disassembly sequence of an industrial product on a head mounted display, and less industrial case studies, such as the manual skills development of carpenters for AEC sectors and the surgeon training in the pre – operative planning in medical field.
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Li, Jinmin. "Integrating Building Information Modelling (BIM), Cost Estimating and Scheduling for Buildings Construction at the Conceptual Design Stage". Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/35292.
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Estimating the construction time and cost of a building project is an essential task of construction manager, which benefits owners, engineers and contractors. Construction duration and cost, in particular, have profound influence on the outcome of a project at the conceptual stage of its life. The conventional methods used to estimate the time and costs of construction projects are based on 2D models, which need much time and effort from engineers, estimators and schedulers who are involved in preparing them because all of this process is done manually, especially when the project has several design alternatives. Considering that, Building Information Modelling (BIM), which is a technology that enhances data transfer and ensures cooperation among designers, engineers, and contractors, can provide an efficient way for cost estimating and schedule planning. On the other hand, sustainability has drawn more and more attention by the construction industry, this is because a project’s construction process has crucial impacts on society, the environment, and the economy. Modular Construction has been proven to ensure sustainable construction by reducing the negative impacts on the environment, reducing construction time, and improving manpower productivity. This research aims at developing an integrated model that interrelates BIM with construction cost estimation, scheduling, and sustainability at the conceptual design stage of projects. The aim is to reduce the preparation time and increase the efficiency of making major decisions for both conventional construction and modular construction.
The proposed model consists of five modules, including a data collection module, a cost estimation module, a scheduling module, a sustainability evaluation module, and a 5D integrated module. Plug-ins were developed in the model to link BIM tool (i.e., Autodesk Revit) with Microsoft Excel to ensure automatic data transfer among these modules all within a BIM platform so that owners and designers can quickly generate a reliable construction cost estimate, construction schedule, preliminary sustainability evaluation, as well as construction process simulation.
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Amaechi, Austin Oguejiofor. "A conceptual system design and managerial complexity competency model". Thesis, Brunel University, 2013. http://bura.brunel.ac.uk/handle/2438/8555.
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Complex adaptive systems are usually difficult to design and control. There are several particular methods for coping with complexity, but there is no general approach to build complex adaptive systems. The challenges of designing complex adaptive systems in a highly dynamic world drive the need for anticipatory capacity within engineering organizations, with a goal of enabling the design of systems that can cope with an unpredictable environment. This thesis explores this question of enhancing anticipatory capacity through the study of a complex adaptive system design methodology and complexity management competencies. A general introduction to challenges and issues in complex adaptive systems design is given, since a good understanding of the industrial context is considered necessary in order to avoid oversimplification of the problem, neglecting certain important factors and being unaware of important influences and relationships. In addition, a general introduction to complex thinking is given, since designing complex adaptive systems requires a non-classical thought, while practical notions of complexity theory and design are put forward. Building on these, the research proposes a Complex Systems Life-Cycle Understanding and Design (CXLUD) methodology to aid system architects and engineers in the design and control of complex adaptive systems. Starting from a creative anticipation construct - a loosening mechanism to allow for more options to be considered, the methodology proposes a conceptual framework and a series of stages to follow to find proper mechanisms that will promote elements to desired solutions by actively interacting among themselves. To illustrate the methodology, a financial systemic risks infrastructure systems architecture development case study is presented. The final part of this thesis develops a conceptual model to analyse managerial complexity competency model from a qualitative phenomenological study perspective. The model developed in this research is called Understanding-Perception-Action (UPA) managerial complexity competency model. The results of this competency model can be used to help ease project manager’s transition into complex adaptive projects, as well as serve as a foundation to launch qualitative and quantitative research into this area of project complexity management.
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Mathews, Jim David. "Optimisation and decision support during the conceptual stage of building design : new techniques based on the genetic algorithm". Thesis, University of Plymouth, 2000. http://hdl.handle.net/10026.1/726.
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Modern building design is complex and involves many different disciplines operating in a fragmented manner. Appropriate computer-based decision support (DS) tools are sought that can raise the level of integration of different activities at the conceptual stage, in order to help create better designs solutions. This project investigates opportunities that exist for using techniques based upon the Genetic Algorithm (GA) to support critical activities of conceptual building design (CBD). Collective independent studies have shown that the GA is a powerful optimisation and exploratory search technique with widespread application. The GA is essentially very simple yet it offers robustness and domain independence. The GA efficiently searches a domain to exploit highly suitable information. It maintains multiple solutions to problems simultaneously and is well suited to non-linear problems and those of a discontinuous nature found in engineering design. The literature search first examines traditional approaches to supporting conceptual design. Existing GA techniques and applications are discussed which include pioneering studies in the field of detailed structural design. Broader GA studies are also reported which have demonstrated possibilities for investigating geometrical, topological and member size variation. The tasks and goals of conceptual design are studied. A rationale is introduced, aimed at enabling the GA to be applied in a manner that provides the most effective support to the designer. Numerical experiments with floor planning are presented. These studies provide a basic foundation for a subsequent design support system (OSS) capable ofgenerating structural design concepts. A hierarchical Structured GA (SGA) created by Oasgupta et al [1] is investigated to support the generation of diverse structural design concepts. The SGA supports variation in the size, shape and structural configuration of a building and in the choice of structural frame type and floor system. The benefits and limitations of the SGA approach are discussed. The creation of a prototype DSS system, abritrarily called Designer-Pro (OPRO), is described. A detailed building design model is introduced which is required for design development and appraisal. Simplifications, design rationale and generic component modelling are mentioned. A cost-based single criteria optimisation problem (SCOP) is created in which other constraints are represented as design parameters. The thesis describes the importance of the object-oriented programming (OOP) paradigm for creating a versatile design model and the need for complementary graphical user interface (Gill) tools to provide human-computer interaction (HCI) capabilities for control and intelligent design manipulation. Techniques that increase flexibility in the generation and appraisal of concept are presented. Tools presented include a convergence plot of design solutions that supports cursor-interrogation to reveal the details of individual concepts. The graph permits study of design progression, or evolution of optimum design solutions. A visualisation tool is also presented. The DPRO system supports multiple operating modes, including single-design appraisal and enumerative search (ES). Case study examples are provided which demonstrate the applicability of the DPRO system to a range of different design scenarios. The DPRO system performs well in all tests. A parametric study demonstrates the potential of the system for DS. Limitations of the current approach and opportunities to broaden the study form part of the scope for further work. Some suggestions for further study are made, based upon newly-emerging techniques.
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Steele, Steven Cory Wyatt. "Optimal Engine Selection and Trajectory Optimization using Genetic Algorithms for Conceptual Design Optimization of Resuable Launch Vehicles". Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/51771.
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Proper engine selection for Reusable Launch Vehicles (RLVs) is a key factor in the design of low cost reusable launch systems for routine access to space. RLVs typically use combinations of different types of engines used in sequence over the duration of the flight. Also, in order to properly choose which engines are best for an RLV design concept and mission, the optimal trajectory that maximizes or minimizes the mission objective must be found for that engine configuration. Typically this is done by the designer iteratively choosing engine combinations based on his/her judgment and running each individual combination through a full trajectory optimization to find out how well the engine configuration performed on board the desired RLV design.
This thesis presents a new method to reliably predict the optimal engine configuration and optimal trajectory for a fixed design of a conceptual RLV in an automated manner. This method is accomplished using the original code Steele-Flight. This code uses a combination of a Genetic Algorithm (GA) and a Non-Linear Programming (NLP) based trajectory optimizer known as GPOPS II to simultaneously find the optimal engine configuration from a user provided selection pool of engine models and the matching optimal trajectory. This method allows the user to explore a broad range of possible engine configurations that they wouldn't have time to consider and do so in less time than if they attempted to manually select and analyze each possible engine combination.
This method was validated in two separate ways. The codes ability to optimize trajectories was compared to the German trajectory optimizer suite known as ASTOS where only minimal differences in the output trajectory were noticed. Afterwards another test was performed to verify the method used by Steele-Flight for engine selection. In this test, Steele-Flight was provided a vehicle model based on the German Saenger TSTO RLV concept and models of turbofans, turbojets, ramjets, scramjets and rockets. Steele-Flight explored the design space through the use of a Genetic Algorithm to find the optimal engine combination to maximize payload. The results output by Steele-Flight were verified by a study in which the designer manually chose the engine combinations one at a time, running each through the trajectory optimization routine to determine the best engine combination. For the most part, these methods yielded the same optimal engine configurations with only minor variation.
The code itself provides RLV researchers with a new tool to perform conceptual level engine selection from a gathering of user provided conceptual engine data models and RLV structural designs and trajectory optimization for fixed RLV designs and fixed mission requirement.Master of Science
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Li, Chung-lun. "Conceptual design of single and multiple state mechanical devices : an intelligent CAD approach /". Hong Kong : University of Hong Kong, 1998. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19712108.
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Rasmussen, Måns. "Conceptual Design of an Air-Launched Three-Staged Orbital Launch Vehicle". Thesis, KTH, Rymdteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-302775.
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The objective of this study was to design a launch vehicle capable of deploying a nanosatellite into a Sun-synchronous orbit at 500 km orbital altitude from the JAS 39E/F Gripen fighter aircraft. This was achieved by first performing theoretical calculations for the required nozzles and solid propellant grain configurations for the first two solid stages, followed by the necessary liquid propellant configuration for the third stage. Lastly, two methods were investigated in solving the trajectory ascent problem for the launch vehicle design. First, by stating the trajectory problem as an initial value problem while guessing a Sigmoidal steering law. Secondly, by stating the trajectory problem as a boundary value problem. The latter was solved by transcribing the trajectory problem into a nonlinear program where a parametric steering law was derived using a Sequential quadratic programming algorithm.Ultimately, resulting in a launch vehicle design with a gross lift-off mass of 1,289 kg, capable of launching an 8.4 kg payload into the targeted orbit, with suggested modifications to increase the possible payload mass to 12.9 kg.Målet med den här studien var att designa en luftlanserad trestegsraket kapabel till att transportera en nanosatellit upp till en solsynkron omloppsbana på 500 km altitud från ett JAS 39E/F Gripen jaktflygplan. Det gjordes genom att först beräkna de nödvändiga dysorna och krutladdningsformerna för de två första stegen tillsammans med en flytande bränsledesign för det tredje steget. Två metoder undersöktes för bananalysen. Först genom att anta en Sigmoidal styrningsfunktion för pitchen, sedan genom att transkribera problemet till ett icke-linjärt program där en parametrisk styrlag togs fram genom att använda en Sequential quadratic programming algoritm. Slutligen presenterades en raketdesign med en total vikt på 1 289 kg, kapabel till att skjuta upp en nyttolast på 8,4 kg till den önskade omloppsbanan tillsammans med förslag som kan öka den möjliga nyttolasten till 12,9 kg.
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李仲麟 i Chung-lun Li. "Conceptual design of single and multiple state mechanical devices: an intelligent CAD approach". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1998. http://hub.hku.hk/bib/B31237332.
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Markiz, Nizar. "An Expert System Integrated with a Bridge Information Management System (BrIMS), Cost Estimating, Deterioration Forecasting, and Linear Scheduling at the Conceptual Design Stage". Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/37195.
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Major bridge stakeholders such as federal and provincial transportation agencies are in dire need for objective knowledge-based systems that assist decision-makers in the selection of bridge type. Besides that, estimating bridge construction costs at the conceptual design stage is an increasing necessity for accurate budgeting and effective allocation of funding. Whilst multiple bridge management systems have already been developed; they still possess major drawbacks pertaining to interoperability and integration with complex time and cost optimization-related problem solving. In another perspective, infrastructure restoration has been backlogged with multifaceted factors that have captured the attention of municipal and federal authorities. Several successful integrations of bridge information management systems (BrIMS) with decision support systems and computer-aided engineering design solutions have significantly leveraged downstream processes of bridge maintenance operations and inspired many researchers. The subjective nature of evaluating bridge conditions and deteriorations is the main factor that influences bridge maintenance, repair, and replacement decisions. In order to overcome this shortcoming, the objectives of this study are intended to demonstrate the viability of integrating a decision support system with a stochastic gamma deterioration model utilizing a probabilistic fuzzy logic strategic approach at the conceptual design stage.
In summary, this study presents a systematic multi-objective knowledge-based approach for selecting bridge type, forecasting elemental deteriorations, linear scheduling, and estimating construction costs at the conceptual design stage. The proposed methodology comprises a framework to deploy a system that automatically generates conceptual cost estimates by integrating objective functions with bridge information modeling (BrIM) through an external data interchange protocol in synchrony with interoperability standards. Deployment of the developed system shall minimize the degree of subjectivity involved while decision makings pertaining to bridge projects and assists designers and cost engineers obtain results in an integrated quantitative, qualitative, and systematic manner. The successful deployment of the expert system signifies a technological achievement of novelty pertaining to the integration of bridge information modeling (BrIM) concept with probabilistic fuzzy logic strategic approaches at the conceptual design stage of bridges.
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Singh, Isherdeep. "Structural fidelity variation for aircraft wing configurations : design exploration and optimisation in conceptual and preliminary design Stages". Thesis, University of Southampton, 2018. https://eprints.soton.ac.uk/427149/.
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In an aircraft design process, as the design progresses through various design stages, concerted effort to introduce optimization capabilities, explore alternate designs, and introduce novel ideas becomes limited by the process chains, and reliance on higher fidelity analysis. Therefore introduction of global search and optimisation capability is limited to the conceptual design stage, where lower fidelity tools are utilised. These tools, although verified and validated for known trends, limit the exploration of novel design spaces, as they are reliant on empirical data sets. In this work a multidisciplinary program, which is designed to utilise physics based tools to achieve design exploration capabilities, is presented. In addition to this, the code presented aids in the assessment of the impact of structural analysis on the observed design space, for top level geometric parameters. The importance of fidelity variation on the design exploration of the wing configuration for mass, drag and cost is also explored. Presented in this work are trends for wing performance characteristics derived from models for varying structural fidelity, for variations in Aspect Ratio (AR), Sweep (SWPI), Area (SG), and thickness to chord at the root (t/cr). The models include; a simple beam model, a three dimensional wing box model (with spars, covers, and ribs), and the three dimensional wing box model with the addition of stingers. The trend variance resulting from the inclusion of incremental physics, and certification based analysis in the coupled structural and aerodynamic analysis, provides a guide to the fidelity required to successfully optimise the aircraft wing configuration. Following the assessment of trends, sensitivity studies are conducted for multiple variables, at different levels of structural fidelity. These sensitivity studies allow the visualisation of the wing performance characteristics in two and three dimensions, and facilitate the understanding of design variable sensitivity. Finally Response Surface Models (RSMs) and design space visualisation studies (using parallel and hierarchical axes techniques, and Pareto fronts) were conducted in order to fulfil the overall aims of the thesis; appropriate structural fidelity selection, reduction of the data overhead between design levels, and design space exploration.
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Xu, Changxin. "Computational foundations for computer aided conceptual design of multiple interaction-state mechatronic devices". College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2612.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2005.Thesis research directed by: Mechanical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Elgayar, Aly. "Integrating Bridge Information Modeling (BRIM), Bridge Sustainability Rating System (BRSRS), Bridge Environmental Performance Strategy Mapping (BREPSM) and Cost Estimating At the Conceptual Design Stage". Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36570.
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Bridges are crucial infrastructure for urban development as cities rely heavily on various modes of transportation for access and mobility. In an effort to fill the gap in the knowledge and methodology used in the construction of sustainable bridges, a model is developed using the concept of BrIM having the capabilities to develop bridges at the conceptual design stage, which offers ample versatility to influence stakeholders’ decisions towards sustainable bridge design. The model incorporates a knowledge-based decision support system and four modules namely: BrIM module; the first ever Bridge Sustainability Rating System (BrSRS) module; Bridge Environmental Performance Strategy Map (BrEPSM) module; and a conceptual cost estimating module. The model takes fundamental data input and processes it through the knowledge-based system established based on MTO’s Highway Geometric Design and the Navigational Waterways Clearance guidelines. The sustainability capabilities of the model are broken into two sub- modules; a BrSRS was developed by using the amalgamation of various existent highways and roads sustainability rating systems and by considering the introduction of bridge design. The system mimics the style of LEED as users can select from a weighted list of sustainable construction activities and materials to accumulate credits towards a sustainability classification. The second includes a BrEPSM that the forecasts footprints levels of bridge projects based on 5 footprint indicators namely; carbon; water; energy; emissions; and work environment with data obtained from Statistics Canada pertaining to each footprint illustrated on a radar graph. The third module takes the knowledge-based output and presents it in 3D mode via AutoCAD allowing users to alter the drawing’s dimensions and accordingly the model reiterates the calculations based on the changes made in the 3D CAD model. The final module generates an approximate cost estimate of the conceptually designed bridge, which is ideal for the feasibility study of the project.
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KOHLI, Gurpreet, i gkohli@student ecu edu au. "An Investigation into the Use of B-Nodes and State Models for Computer Network Technology and Education". Edith Cowan University. Computing, Health And Science: School Of, 2006. http://adt.ecu.edu.au/adt-public/adt-ECU2006.0020.html.
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This thesis consists of a series of internationally published, peer reviewed, conference research papers and one journal paper. The papers evaluate and further develop two modelling methods for use in Information Technology (IT) design and for the educational and training needs of students within the area of computer and network technology. The IT age requires technical talent to fill positions such as network managers, web administrators, e-commerce consultants and network security experts as IT is changing rapidly, and this is placing considerable demands on higher educational institutions, both within Australia and internationally, to respond to these changes.
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Kohli, Gurpreet. "An investigation into the use of B-Nodes and state models for computer network technology and education". Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2005. https://ro.ecu.edu.au/theses/78.
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This thesis consists of a series of internationally published, peer reviewed, conference research papers and one journal paper. The papers evaluate and further develop two modelling methods for use in Information Technology (IT) design and for the educational and training needs of students within the area of computer and network technology. The IT age requires technical talent to fill positions such as network managers, web administrators, e-commerce consultants and network security experts as IT is changing rapidly, and this is placing considerable demands on higher educational institutions, both within Australia and internationally, to respond to these changes.
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Olivier, Marius. "The conceptual design and development of novel low cost sensors for measuring the relative light emission in the pre-millisecond stages of detonating explosive charges". Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71686.
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Thesis (MScEng)--Stellenbosch University, 2012.ENGLISH ABSTRACT: During the course of the CSIR’s research into the characterisation of explosive sources to devise methods of active intervention against threats, the need has arisen to research a particular means of early identification of the threat, which is the intense light flash during the threat detonation. For this purpose, a low cost rugged fast optical sensor was sought, since the application thereof would imply possible destruction, especially if integrated into an active intervention system later on. Given the average time of about 1ms available for intervention, it is clear that the active intervention system needs to operate within that period, hence the interest in the characteristic light emission of detonations in the pre-millisecond time frame. It was thought that by characterising this emitted light in terms of wavelength (temperature) and amplitude (and maybe other unique phenomena), the size of the threat could be determined and logic decisions derived therefrom. Needless to say, the environment in which the detonation light emission sensor is to operate, is extremely hostile in terms of shock, dust, flying debris, fast rise time of the explosive event, and Electro-magnetic Interference ( EMI) caused by the detonation itself. It must be noted that the light sensor research was driven by the outcome of research tests performed in aid of the development of an active intervention system. During this research the possibility of using commercially available low cost optical detectors at room temperature in combination with cost effective narrow band pass op- tical filters for the relative measurement of the light emission at discrete wavelengths during explosive detonation events were investigated. In 2006, not much applicable lit- erature could be found on this subject, hence the educated “shot-in-the-dark” approach then, which, by a systematic approach of explosive tests and continuous evaluation up to 2011, led to a surprisingly simple and robust low cost optical sensor. The research commenced with a range of optical detector elements selected for their responsivity and bandwidth in the optical spectrum of interest; the optical filtering by means of the recording of the emitted light signal during scaled down explosive tests at the Blast Impact Survivability Research Unit (BISRU) at the University of Cape Town. These tests were followed by full-scale tests at DBEL, and confirmed the findings at BISRU that the light emissions at the longer wavelengths (>2 m) manifest themselves too late for use within the intervention time frame. It was therefore decided to concentrate on the ultra-violet (UV) to near infra-red (NIR) spectrum of the emitted light for further full scale tests, since these discrete spectra showed the most promise for characterisa- tion of the emitted light. During this period a robust sensor housing with detector and filter mounts was designed for protection against blast shock and EMI. During the following years, certain types of optical detectors that were used during previous tests were eliminated according to results obtained, and more discrete narrow band pass filters added in the visible to NIR spectrum. A dedicated fast instrumen- tation amplifier (bandwidth > 1MHz and selectable gain up to 40dB) was developed to amplify weak signals (mainly caused by the heavy load in the detector circuit to improve rise times). However, the emission of light per wavelength in this region was measured to be relatively strong, and actually not as fast as was anticipated. This meant that the load resistor value of the detector element could be increased without affecting the signal negatively (bandwidth sufficient), thus adding to the amplitude of the signal to such a point that amplification in a 10m to 30 meter stand-off scenario was no longer needed. This culminated in an unamplified universal detector element being used with various narrow band pass filters up to 1 m, integrated as a very robust analog sensor at a discrete wavelength, and facilitating the direct comparison of light amplitude/relative intensity of the detonation at discrete spectral points. The sensor was employed in the field at various full scale explosive tests at DBEL, which led to the capture of a vast amount of light emitted data for different types of explosives, at various distances from the detonation, and of varying mass. Analysis of this data showed that the broadband light intensity of the emitted light scales to the explosive mass1/3 (as published by FJ Mostert and M Olivier in the Journal for Applied Physics, October 2011). Further analysis also confirmed the attenuation of the emitted light intensity by the square of the distance. Besides the aforesaid, various other key inputs to a possible active intervention algorithm have been identified. These findings are inputs to the determination of i.a. the detonation threat size, a vital component in the active intervention algorithm. The results of these experiments confirmed that the final low cost analog sensor can measure relative light emission at discrete wavelengths from detonation of explosives in the very early stages of development, and that the sensor has many other applications in the detonics research fields as well.
AFRIKAANSE OPSOMMING: Gedurende die WNNR se navorsing om detonerende bronne te karakteriseer ten einde aktiewe teenmaatreëls daar te stel, het die behoefte na vore gekom om die intense ligflits van ’n detonasie te ondersoek en te karakteriseer. Vir hierdie doel is ’n lae koste ligsensor benodig, synde die uiteindelike aanwending van hierdie ligsensor die vernietiging daarvan sou beteken, aldus die lae koste vereiste. Gegewe die kort tydsduur van die detonasie (’n paar millisekondes), is dit duidelik dat die ligflits karakerisering voor 1ms moet geskied, en daarom moet die ligsensor ook baie vinnig reageer om insette te lewer tot ’n aktiewe teenmaatreëlstelsel. Daar moet op gelet word dat die ligsensor se ontwikkeling uitkomsgedrewe was deur die navorsingstoetse om ’n aktiewe teenmaatreëlstelsel daar te stel. Een van die insette tot so ’n aktiewe teenmaatreëlstelsel is die grootte van die bedreiging: deur die ligflits te karakteriseer met die lae koste ligsensors t.o.v. golflengte, ligamplitude en moontlik ander verskynsels, kan bv. die massa inset verkry word wat nodig is vir die teenmaatreël algoritme. Die omgewing waarin die ligsensor moet funksioneer is baie onvriendelik i.t.v. skok, stof, vlieënde partikels en elektromagnetiese steurings, en sou daarteen beskerm moes word. Gedurende die navoring om so ’n ligsensor te ontwikkel (samelopend met die teen- maatreël navorsing), is kommersiële kamertemperatuur detektors oorweeg en aange- wend, in samewerking met nouband optiese filters. Die doel was om die ligopbrengs per golflengte te karakteriseer m.b.t. die plofstof massa, plofstof tipe en geometrie, en die afstand vanaf die detonasie. Bitter min literatuur oor die ligmeting van detonasies is aanvanklik gevind, aldus is ’n basislyn daargestel en deur sistematiese toetsing, ontleding en verbetering voortgegaan met die navorsing. Dit het gelei tot ’n verrassend eenvoudige en verharde lae koste ligsensor, wat deur meting sleutelinsette kon lewer tot die gesogte aktiewe teenmaatreël algoritme. Kommersiële detektors en nouband optiese filters is uitgesoek na aanleiding van hul prys en prestasie, en waar nodig, is versterking van die seine aangebring. Verskeie toetse met plofstof (op klein en groot skaal) is uitgevoer, waartydens ligmeting by spesifieke golflengtes opgeneem is. Analise van hierdie data het getoon dat die langer golflengtes (>2 m) se verskyning te laat is vir insluiting in die teenmaatreël algoritme, en is dus geleidelik (of sistematies) uitgeskakel. Die klem het geskuif na die detonasie liguitsetting in die UV tot naby infrarooi spektrum, wat nuwe detektors en filters tot gevolg gehad het (uitkoms gebasseerde navorsing). In die proses is ’n instrumentasie versterker ontwerp en gebou, vir buffering en versterking van seine hoër as 1 MHz met ’n selekteerbare aanwins van tot 40dB. Toetse met volskaalse ladings het egter getoon dat die liguitset besonder sterk is in die UV tot naby infrarooi spektrum, en ’n onversterkte ligsensor is aldus op die proef gestel. Hierdie proeflopie het getoon dat die onversterkte ligsensor besonder goed funksioneer op afstande tot en met 30m, en daar is op hierdie model voortgebou. Die verharde onversterkte ligsensor is aangewend in verskeie verdere volskaalse plofstof toetse, en het data gelewer t.o.v. detonasie liguitstraling by spesifieke golflengtes vir tipes plofstof, plofstof massas, plofstof geometrie en afstande vanaf die detonasie. Analise van hierdie data het getoon dat breëband liguitsetting se intensiteit skaal met die plofstof massa1=3 (gepubliseer as ’n artikel deur FJ Mostert en M Olivier in die Journal of Applied Physics’ - Oktober 2011). Verdere analise het verskeie sleutelinsette tot ’n aktiewe teenmaatreël algoritme geïdentifiseer. Die uitkoms van hierdie eksperimentele navorsing het getoon dat die lae koste lig- sensor relatiewe liguitsetting van ’n detonasie by gekose golflengtes vinnig kan meet in die baie vroeë stadia van die detonasie. Buiten dit, het die sensor verskeie ander nuttige aanwending in die detonasie navorsingsveld.
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Fialko, Jessica Anne. "Graduate stage design". Thesis, University of Iowa, 2013. https://ir.uiowa.edu/etd/2492.
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Miller, Andrew Scott. "Compressor conceptual design optimization". Thesis, Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53598.
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Gas turbine engines are conceptually designed using performance maps that describe the compressor’s effect on the cycle. During the traditional design process, the cycle designer selects a compressor design point based on criteria to meet cycle design point requirements, and performance maps are found or created for off-design analysis that meet this design point selection. Although the maps always have a pedigree to an existing compressor design, oftentimes these maps are scaled to account for design or technology changes. Scaling practices disconnect the maps from the geometry and flow associated with the reference compressor, or the design parameters which are needed for compressor preliminary design. A goal in gas turbine engine research is to bridge this disconnect in order to produce acceptable performance maps that are coupled with compressor design parameters.
A new compressor conceptual design and performance prediction method has been developed which will couple performance maps to conceptual design parameters. This method will adapt and combine the key elements of compressor conceptual design with multiple-meanline analysis, allowing for a map of optimal performance that is attached to reasonable design parameters to be defined for cycle design. This method is prompted by the development of multi-fidelity (zooming) analysis capabilities, which allow compressor analysis to be incorporated into cycle analysis. Integrating compressor conceptual design and map generation into cycle analysis will allow for more realistic decisions to be made sooner, which will reduce the time and cost used for design iterations.
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Karlsson, Albin, i Anton Lomaeus. "Transport Aircraft Conceptual Design". Thesis, KTH, Skolan för teknikvetenskap (SCI), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210778.
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A conceptual design for a transport aircraft has been created, tailored for human-itarian missions along the equator with its home base in the European Union while optimizing for fuel eciency and speed. An initial estimate of the empty weight was made using historical data and Breguet equations, based on a required payload of 60 tonnes and range of 5 500 nautical miles. A constraint diagram consisting of require-ments for stall speed, takeo distance, climb rate and landing distance was used to determine wing loading and thrust to weight ratio, resulting in a main wing area of 387m 2 and thrust to weight ratio of 0:224, for which two Rolls Royce Trent 1000-H engines were selected. A high aspect ratio wing was designed with blended winglets to optimize against lift induced drag. Wing placement and tail volume were decided by iterative calculations, resulting in a centre of lift located aft of the centre of gravity during all stages of the mission. The resulting aircraft model has a high wing with a span of 62 m, length of 49m with a takeo gross weight of 221 tonnes, of which 83 tonnes are fuel.
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CHOOBINEH, JOOBIN. "FORM DRIVEN CONCEPTUAL DATA MODELING (DATABASE DESIGN, EXPERT SYSTEMS, CONCEPTUAL)". Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/188043.
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Conceptual data schema is constructed from the analysis of the business forms which are used in an enterprise. In order to peform the analysis a data model, a forms model, and heuristics to map from the forms model to the data model are developed. The data model we use is an extended version of the Entity-Relationship Model. Extensions include the addition of the min-max cardinalities and generalization hierarchy. By extending the min-max cardinalities to attributes we capture a number of significant characteristics of the entities in a concise manner. We introduce a hierarchical model of forms. The model specifies various properties of each form field within the form such as their origin, hierarchical structure, and cardinalities. The inter-connection of the forms is expressed by specifying which form fields flow from one form to another. The Expert Database Design System creates a conceptual schema by incrementally integrating related collections of forms. The rules of the expert system are divided into six groups: (1) Form Selection, (2) Entity Identification, (3) Attribute Attachment, (4) Relationship Identification, (5) Cardinality Identification, and (6) Integrity Constraints. The rules of the first group use knowledge about the form flow to determine the order in which forms are analyzed. The rules in other groups are used in conjunction with a designer dialogue to identify entities, relationships, and attributes of a schema that represents the collection of forms.
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Morberg, Hampus. "Conceptual Speaker Study". Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Maskinteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-25081.
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This thesis project is a stand-alone project with the goal to develop an optimized material suited for speaker cabinets, with the focus on acoustic abilities, production possibilities and environmental impact. And to further on design a high performance to price speaker, using the developed material properties and todays technology. The thesis is focused heavily on testing material, starting with research and thereafter creating and testing samples, to continue with find a material combination that would work for a product fit for the market. The final product should fulfill the demands of typical furniture handling, meaning it should be able to be moved around and withstand moderate abuse from daily events. The project results in a functional prototype for evaluation of material and the overall design. The project is based on design methods and design thinking.
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Vangbo, Petter Olav. "CFD in conceptual ship design". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-15480.
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Computational Fluid Dynamics (CFD) has been around for many years. It is a computer tool that can be used to find the hydrodynamic fluid performances. In ship design it is used in a wide area from smoke propagation to resistance estimations. It is however in resistance estimations that CFD have had most focus and research. There are many tools a designer can make use of nowadays. Most of the tools are computer based. This is optimization algorithms, computer aided design (CAD) and computational fluid dynamics (CFD). Using the tools should shorten the time of ship design and make better solutions. I have used a computer tool that mixes optimization with model variation (CAD) and verification (CFD). My conclusion is that it is a powerful tool to use, but should be handled with care. Few variables in the optimization process are important. Conceptual design methodology could be broken down to two outer ranges; point based design and set based design. The methods are quite different when approaching a complex design problem. There seems to be some favor in set based design when coming to a global ‘optimized’ solution to the design problem. More knowledge is gathered in set based design before deciding the final requirements and parameters. This is especially in new developing design where little knowledge is produced in the past. CFD is a broad term. There is many different methods and area of use. In this thesis I will break it down to two terms; potential codes and RANSE codes. Potential codes are easy, robust and well developed. RANSE codes are difficult, takes a lot of time and not so well developed. Potential codes are used in areas where turbulent flows are not present, while RANSE codes are used when it is present and important to the result. If designing new innovative hulls CFD should be used earlier in the design process and with a simulation driven design approach. Simulation driven design could be used with potential codes or RANSE codes. To have a high value rate of the modeling potential codes should be used when many sets of variation I needed and turbulence is not important to the answers. RANSE code should be used when turbulent flow is important to the answer, but must be done with few sets of variations because of high computational effort. If designing a more standard ship, CFD should be used in a modeling design approach to verify the performance estimations that have been done earlier in the process.
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Liu, Huimin. "Knowledge-based inventive conceptual design". Thesis, Cardiff University, 2007. http://orca.cf.ac.uk/54627/.
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Conceptual design is the first phase of the design process. Most basic functions of a new product and the solutions for solving design problems are generated in this critical phase, which will affect the attributes in the later detailed design process. Conceptual design, especially the process of concept generation, is an innovation process that is achieved by human intelligence. The intuition and experience of designers play a significant role during the design process which is hard to be replaced by computer-aided tools or artificial intelligence technology. TR1Z is an inventive problem-solving tool to help people improve creativity. It is applied in this work to generate creative design concepts. The TRIZ inventive principles are extended by integrating other TRIZ tools and TRIZ-derived tools. These principles are also restructured by the inspiration of I-Ching. The Behaviour-Entity representation of inventive principles enables the generation of new and innovative solutions based on TRIZ. The TRIZ Contradiction Matrix (CM) and inventive principles are then used to develop the TRIZ-based concept generation approach by adding constraints to the standard Behaviour-Entity representation of TRIZ. This approach is developed to retrieve modified TRIZ inventive principles and to generate new solutions by re-organising the BEC (Behaviour-Entity-Constraint) representation of principles according to the conflicting design requirements. Finally, a negotiation-based approach is integrated with an existing no-compromise approach to develop a knowledge-based system for automatically detecting and resolving conflicts. The recommendation is given as an output arranged by weight to help the designer improve creativity and efficiency for concept generation and conflict resolution in conceptual design. The approach is implemented by using a rule-based language, JESS. A case study of aircraft fuselage layout design is presented to demonstrate the benefits of using this conflict resolution system.
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Solomons, Stanley Nicholls. "Conceptual models in industrial design". Thesis, De Montfort University, 1988. http://hdl.handle.net/2086/4144.
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King, Martin Graham. "The hierarchy of conceptual design". Thesis, University of Salford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272688.
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Agnesi, Vittorio C. (Vittorio Carlos). "Conceptual design of membrane structures". Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/49997.
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Serrano, David. "Constraint management in conceptual design". Thesis, Massachusetts Institute of Technology, 1987. http://hdl.handle.net/1721.1/14689.
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Sokolova, I. "Conceptual Design of Texts-Announcements". Thesis, Хмельницький державний університет, 2002. http://essuir.sumdu.edu.ua/handle/123456789/63474.
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The paper is dedicated to analysis of conceptual model of texts-announcements, which reflects a derivative character of this type of texts. It is defined that text-announcement as an informative-advertising and a derivative type of texts is pragmatically directed to preparation of addressees for a newly published text reception.
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Brown, Charles Wayne. "Interactive constraint based conceptual design /". The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487682558443493.
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Doering, Sharon. "Human Trafficking Recovery: Conceptual and Dimensional Considerations in a Stage Model". University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1336508012.
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McClain, Lewis R. "Design-build interoperability and conceptual design and development". Available online, Georgia Institute of Technology, 2007, 2007. http://etd.gatech.edu/theses/available/etd-04062007-132656/.
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Rottier, Johannes. "Conceptual design of an organisational capability". Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-11092006-121921/.
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Guroglu, Serkan. "An Evolutionary Methodology For Conceptual Design". Phd thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606422/index.pdf.
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The main goal of this thesis is the development of a novel methodology to generate creative solutions at functional level for design tasks without binding solution spaces with designers&rsquoindividual experiences and prejudices. For this purpose, an evolutionary methodology for the conceptual design of engineering products has been proposed. This methodology performs evaluation, combination and modification of the existing solutions repetitively to generate new solution alternatives. Therefore, initially a representation scheme, which is generic enough to cover all alternatives in solution domain, has been defined. Following that, the evolutionary operations have been defined and two evaluation metrics have been proposed. Finally, the computer implementation of the developed theory has been performed. The test-runs of developed software resulted in creative alternatives for the design task. Consequently, the evolutionary design methodology presents a systematic design approach for less experienced or inexperienced designers and establishes a base for experienced designers to conceive many other solution alternatives beyond their experiences.
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Karuppoor, Srinand Sreedharan. "Tools for innovation and conceptual design". Texas A&M University, 2003. http://hdl.handle.net/1969.1/1260.
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The ability to design is the distinguishing characteristic of an engineer. Recent research has increased our understanding of both the engineering design process and effective means for teaching that process to neophyte design engineers. In that spirit, a design methodology was developed at the Institute for Innovation and Design in Engineering (IIDE), Texas A&M University. At the core of this approach is a design philosophy based on the cognitive skills of Abstraction, Critical Parameter Identification, and Questioning. This philosophy along with the design process is taught in the senior undergraduate design and graduate design courses. The goal of the methodology is not only to teach the design process to novice designers but also to instill in them the design philosophy that would enable them to perform design effectively and innovatively in any area of specialty.
In this dissertation the design philosophy along with its role in the design methodology is explained. The Need Analysis and the Conceptual Design stages of the IIDE methodology are elaborated. The weaknesses in these stages are identified and addressed, by developing and incorporating design methods and techniques that fit the spirit and framework of the IIDE design methodology. The Object Function Method was developed to address certain aspects at the Need Analysis stage. There was need for an effective concept searching method within the Concept Design stage of the IIDE design methodology. This is addressed by the development of new search techniques and methods for effective concept discovery during concept searching. The usage and application of these methods and techniques is explained in detail along with examples.
Additionally, this dissertation contains the results of a study conducted with two groups of senior design students, those who have been through the process and those who have not, to evaluate the effectiveness of applying the IIDE design philosophy and performing the Need Analysis and Conceptual Design stages for the given design challenge. The goal of the study was to investigate the relationship, if any, between the degree to which these aspects of the design methodology were followed and the quality of the resulting design solutions produced.
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Uebel, Karl. "Conceptual Design of Complex Hydromechanical Transmissions". Doctoral thesis, Linköpings universitet, Fluida och mekatroniska system, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-142895.
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This thesis explores the conceptual design process of complex hydromechanical transmissions for mobile working machines. Efficient methods for design optimisation and controller development are presented to support the final concept selection. In the endeavour to develop new fuel-efficient driveline solutions for construction machines and off-road equipment new complex hydromechanical transmission concepts are being investigated. This pursuit is driven by stricter emission legislation, high fuel prices and a desire for a greener image both for customers and manufacturers. The trend towards more complex transmission architectures increases the need for more sophisticated product development methods. Complex multiple-mode transmissions are difficult to design and prototype and can be realised in a great number of architectures. By introducing a secondary energy storage in the machine the design space expands further for both hardware and software. There is accordingly a need for more reliable concept assessment in early design stages and the possibility to support concurrent engineering throughout the development process. Previous research on the design and development of hydromechanical transmissions has been limited to analysis of fixed concept designs or design optimization using very simple performance indicators. Existing methodologies for electrified on-road vehicles are not suitable for off-road working machines with hydromechanical transmissions and hydraulic energy storage. The proposed conceptual design process uses detailed quasi-static simulation models and targets to optimise the fuel efficiency of the specific machine specifications and operations. It is also shown how high-speed dynamic simulations can be used for controller development and hardware-in-the-loop simulations to support an efficient product design process. The methods are demonstrated for typical use cases targeting new transmission development for construction machines. Software control development is also treated using control optimisation and real-time simulation. Finally a novel hybrid hydromechanical motion system is presented for which an efficient design process is crucial to its end performance.In the printed verison the series name Linköping studies in Arts and Science is incorrect. The correct series name is Linköping studies in science and technology. Dissertations.
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Tanaka, Asterio Kiyoshi. "On conceptual design of active databases". Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/8299.
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Steele, John. "The interdisciplinary conceptual design of buildings". Thesis, Loughborough University, 2000. https://dspace.lboro.ac.uk/2134/6867.
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The Interdisciplinary Conceptual Design of Buildings Design activity during the conceptual phase of building projects is dynamic, vibrant and as a result, chaotic in appearance. This problem is compounded by the fact that iterative, or cyclic, design progression is often criticised, with the concept of 'going round in circles' being one that is discouraged. However, designbis a learning activity and, owing to the complexity of contemporary building projects,it is often only by moving ahead to improve knowledge, before taking a step back to re-address a problem with improved understanding, that the design process can progress. Today's design professionals are being urged to undertake early design activity in a more programmable, and thus manageable fashion. As such, it is becoming increasingly apparent that designers have little, if any, shared understanding of what conceptual design actually involves, let alone a deeper knowledge of the structure of iterative progression. This can, and is, causing problems for the industry, as the lack of both common understanding and synchronisation in interdisciplinary thinking is resulting in design team fragmentation and adversarial relationships. By modelling design activity it is possible to simplify, and thus ease understanding of, its complexities. The development and trialling of a generic framework of design phases and activities has allowed a simple graphical means of recording and displaying patterns of design progression to be devised. The models produced have been used to study and analyse the patterns of iterative working, the output of which has enabled a clarification of conceptual design practice to be achieved. A web-based design system has been developed from the paper-based framework. This accords well with the richly iterative and often non-linear process which design typically follows and is intended to encourage creativity without imposing a rigid procedure. The tool offers alternative routes through conceptual design, and contains 'Team Thinking Tools' to help designers widen the solution space, set priorities and evaluate options. In addition, it promotes effective teamwork practices to help teams deal with social interactions. Also, at the user's option, the system can be used to capture, store and retrieve decisions made, and the reasoning behind them. This is of key importance in improving the performance of the industry as a whole, for it is only by understanding how the final product is influenced by early design activity, that the design process can be adapted to take account of these issues on future projects.
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Wu, Zhichao. "Modelling collective learning in conceptual design". Thesis, University of Strathclyde, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405494.
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Potter, Stephen. "Artificial intelligence and conceptual design synthesis". Thesis, University of Bath, 2000. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760733.
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