324 resultados para design, conceptions of


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Saudi Arabia experiences housing shortage for mid and low-income families, which is caused by rapid population growth. This condition is worsened by the fact that the current housing supply has problems in meeting both sustainable requirements and cultural needs of those families. This paper aims to investigate the link between the unique conservative Saudi culture and the design of sustainable housing, while keeping the housing cost affordable for mid and low-income families. The paper is based on a review of literatures on the issues of the Islamic culture and how can they be integrated into the design process of a Saudi house. Findings from literature reveiw suggest several design requirements for accommodating the conservative Saudi Culture in low cost sustainable houses. Such requirements include the implementation of proper usage of windows, and house orientation with a courtyard inside rather than facing the main street will provide natural ventilation while maintaining privacy. The main contribution to the body of knowledge is that this is a new approach to sustainable housing in Saudi Arabia considering not only energy use and architectural design issues but also socio-cultural issues as an essential part of sustainability.

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This study compared the performance of a local and three robust optimality criteria in terms of the standard error for a one-parameter and a two-parameter nonlinear model with uncertainty in the parameter values. The designs were also compared in conditions where there was misspecification in the prior parameter distribution. The impact of different correlation between parameters on the optimal design was examined in the two-parameter model. The designs and standard errors were solved analytically whenever possible and numerically otherwise.

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Computational Fluid Dynamics (CFD) simulations are widely used in mechanical engineering. Although achieving a high level of confidence in numerical modelling is of crucial importance in the field of turbomachinery, verification and validation of CFD simulations are very tricky especially for complex flows encountered in radial turbines. Comprehensive studies of radial machines are available in the literature. Unfortunately, none of them include enough detailed geometric data to be properly reproduced and so cannot be considered for academic research and validation purposes. As a consequence, design improvements of such configurations are difficult. Moreover, it seems that well-developed analyses of radial turbines are used in commercial software but are not available in the open literature especially at high pressure ratios. It is the purpose of this paper to provide a fully open set of data to reproduce the exact geometry of the high pressure ratio single stage radial-inflow turbine used in the Sundstrand Power Systems T-100 Multipurpose Small Power Unit. First, preliminary one-dimensional meanline design and analysis are performed using the commercial software RITAL from Concepts-NREC in order to establish a complete reference test case available for turbomachinery code validation. The proposed design of the existing turbine is then carefully and successfully checked against the geometrical and experimental data partially published in the literature. Then, three-dimensional Reynolds-Averaged Navier-Stokes simulations are conducted by means of the Axcent-PushButton CFDR CFD software. The effect of the tip clearance gap is investigated in detail for a wide range of operating conditions. The results confirm that the 3D geometry is correctly reproduced. It also reveals that the turbine is shocked while designed to give a high-subsonic flow and highlight the importance of the diffuser.

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Design researchers have an important role to play when engaged with user-driven design projects in industry. Design researchers can craft ethnographic material to facilitate transfers of user-knowledge to industry, and demonstrate how this material can be used in the design of new products and services. However, ethnographic findings can reveal issues that are in tension with conceptions of the project members from industry. Instead of brushing these tensions aside, we propose provotyping (provocative prototyping) as an approach to constructively build on them as a resource for change. Provotypes are ethnographically rooted, technically working, robust artefacts that deliberately challenge stakeholder conceptions by reifying and exposing tensions that surround a field of organisational interest. The daily and local experience of provotypes aims to stir dialectical processes of reflection on how conceptions currently are, and fuel the front end of a development process by speculating how conceptions could be different. In this article we start by making explicit the relation between provotypes, practices of critical design and organisational sense-making. We then illustrate, through a multi-stakeholder project concerning the field of indoor climate, how provotypes facilitate transfers of user knowledge to industry, and how they contribute to the development of new products and services. We end by framing the role of the design researcher and discuss the politics that are inherent to design provocations.

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Gesture interfaces are an attractive avenue for human-computer interaction, given the range of expression that people are able to engage when gesturing. Consequently, there is a long running stream of research into gesture as a means of interaction in the field of human-computer interaction. However, most of this research has focussed on the technical challenges of detecting and responding to people’s movements, or on exploring the interaction possibilities opened up by technical developments. There has been relatively little research on how to actually design gesture interfaces, or on the kinds of understandings of gesture that might be most useful to gesture interface designers. Running parallel to research in gesture interfaces, there is a body of research into human gesture, which would seem a useful source to draw knowledge that could inform gesture interface design. However, there is a gap between the ways that ‘gesture’ is conceived of in gesture interface research compared to gesture research. In this dissertation, I explore this gap and reflect on the appropriateness of existing research into human gesturing for the needs of gesture interface design. Through a participatory design process, I designed, prototyped and evaluated a gesture interface for the work of the dental examination. Against this grounding experience, I undertook an analysis of the work of the dental examination with particular focus on the roles that gestures play in the work to compare and discuss existing gesture research. I take the work of the gesture researcher McNeill as a point of focus, because he is widely cited within gesture interface research literature. I show that although McNeill’s research into human gesture can be applied to some important aspects of the gestures of dentistry, there remain range of gestures that McNeill’s work does not deal with directly, yet which play an important role in the work and could usefully be responded to with gesture interface technologies. I discuss some other strands of gesture research, which are less widely cited within gesture interface research, but offer a broader conception of gesture that would be useful for gesture interface design. Ultimately, I argue that the gap in conceptions of gesture between gesture interface research and gesture research is an outcome of the different interests that each community brings to bear on the research. What gesture interface research requires is attention to the problems of designing gesture interfaces for authentic context of use and assessment of existing theory in light of this.

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Good daylighting design in buildings not only provides a comfortable luminous environment, but also delivers energy savings and comfortable and healthy environments for building occupants. Yet, there is still no consensus on how to assess what constitutes good daylighting design. Currently amongst building performance guidelines, Daylighting factors (DF) or minimum illuminance values are the standard; however, previous research has shown the shortcomings of these metrics. New computer software for daylighting analysis contains new more advanced metrics for daylighting (Climate Base Daylight Metrics-CBDM). Yet, these tools (new metrics or simulation tools) are not currently understood by architects and are not used within architectural firms in Australia. A survey of architectural firms in Brisbane showed the most relevant tools used by industry. The purpose of this paper is to assess and compare these computer simulation tools and new tools available architects and designers for daylighting. The tools are assessed in terms of their ease of use (e.g. previous knowledge required, complexity of geometry input, etc.), efficiency (e.g. speed, render capabilities, etc.) and outcomes (e.g. presentation of results, etc. The study shows tools that are most accessible for architects, are those that import a wide variety of files, or can be integrated into the current 3d modelling software or package. These software’s need to be able to calculate for point in times simulations, and annual analysis. There is a current need in these software solutions for an open source program able to read raw data (in the form of spreadsheets) and show that graphically within a 3D medium. Currently, development into plug-in based software’s are trying to solve this need through third party analysis, however some of these packages are heavily reliant and their host program. These programs however which allow dynamic daylighting simulation, which will make it easier to calculate accurate daylighting no matter which modelling platform the designer uses, while producing more tangible analysis today, without the need to process raw data.

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Balcony acoustic treatments can be demonstrated to provide important benefits in reducing road traffic noise within the balcony space and consequently internally for any adjacent room. The actual effect on road traffic noise is derived from a multitude of variables that can be broadly categorized into (a) acoustical and (b) geometrical for two distinct propagation volumes being (i) the street space, and (ii) the balcony space. A series of recent research activities in this area has incorporated the use of a combined image and diffuse source model, which can be used to predict the effect of balconies on road traffic noise for large number of scenarios. This paper investigates and presents a method and capability to summarize predictive data into user friendly guidelines aimed for use by acoustical professionals and architects and possible implementation in building design policies for environmental noise. The paper concludes with a presentation of the likely format of a potential design guide.

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Light gauge steel frame wall systems are commonly used in industrial and commercial buildings, and there is a need for simple fire design rules to predict their load capacities and fire resistance ratings. During fire events, the light gauge steel frame wall studs are subjected to non-uniform temperature distributions that cause thermal bowing, neutral axis shift and magnification effects and thus resulting in a combined axial compression and bending action on the studs. In this research, a series of full-scale fire tests was conducted first to evaluate the performance of light gauge steel frame wall systems with eight different wall configurations under standard fire conditions. Finite element models of light gauge steel frame walls were then developed, analysed under transient and steady-state conditions and validated using full-scale fire tests. Using the results from fire tests and finite element analyses, a detailed investigation was undertaken into the prediction of axial compression strength and failure times of light gauge steel frame wall studs in standard fires using the available fire design rules based on Australian, American and European standards. The results from both fire tests and finite element analyses were used to investigate the ability of these fire design rules to include the complex effects of non-uniform temperature distributions and their accuracy in predicting the axial compression strength of wall studs and the failure times. Suitable modifications were then proposed to the fire design rules. This article presents the details of this investigation on the fire design rules of light gauge steel frame walls and the results.

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Purpose – This paper adds to growing research of psychiatric intensive care units (PICU) by recounting descriptions of psychiatric intensive care settings and discusses the perceptions held by nurses of the organisational interfaces, arrangements and provisions of care in these settings. Design/methodology/approach – Data gathered from focus groups held with nurses from two PICUs was used to establish terminology, defining attributes, related concepts, antecedents, values, processes and concepts related to current practices. A literature search was conducted to permit a review of the conceptual arrangements and contemporary understanding of intensive care for people experiencing acute psychiatric illness based on the perspectives held by the nurses from the focus groups. Findings – Dissonance between service needs and the needs and management of individual patients overshadow strategies to implement comprehensive recovery-oriented approaches. Three factors are reported in this paper that influence standards and procedural practice in PICU; organisational structures; physical structures; and subtype nomenclature. Practical implications – Acute inpatient care is an important part of a comprehensive approach to mental health services. Commonly intensive acute care is delivered in specialised wards or units co-located with acute mental health inpatient units mostly known as PICU. Evidence of the most effective treatment and approaches in intensive care settings that support comprehensive recovery for improved outcomes is nascent. Originality/value – Current descriptions from nurses substantiate wide variations in the provisions, design and classifications of psychiatric intensive care. Idiosyncratic and localised conceptions of psychiatric intensive care are not adequately entailing effective treatment and methods in support of recovery principles for improved and comprehensive outcomes. The authors suggest that more concrete descriptions, guidelines, training and policies for provision of intensive psychiatric health care encompassing the perspective of nursing professionals, would reinforce conceptual construction and thus optimum treatments within a comprehensive, recovery-oriented approach to mental health services.

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BACKGROUND Research on engineering design is a core area of concern within engineering education and a fundamental understanding of how engineering students approach and undertake design is necessary in order to develop effective design models and pedagogies. Understanding the factors related to design experiences in education and how they affect student practice can help educators as well as designers to leverage these factors as part of the design process. PURPOSE This study investigated the design practices of first-year engineering students’ and their experiences with a first-year engineering course design project. The research questions that guided the investigation were: 1. From a student perspective, what design parameters or criteria are most important? 2. How does this perspective impact subsequent student design practice throughout the design process? DESIGN/METHOD The authors employed qualitative multi-case study methods (Miles & Huberman, 1994) in order to the answer the research questions. Participant teams were observed and video recorded during team design meetings in which they researched the background for the design problem, brainstormed and sketched possible solutions, as well as built prototypes and final models of their design solutions as part of a course design project. Analysis focused on explanation building (Yin, 2009) and utilized within-case and cross-case analysis (Miles & Huberman, 1994). RESULTS We found that students focused disproportionally on the functional parameter, i.e. the physical implementation of their solution, and the possible/applicable parameter, i.e. a possible and applicable solution that benefited the user, in comparison to other given parameters such as safety and innovativeness. In addition, we found that individual teams focused on the functional and possible/ applicable parameters in early design phases such as brainstorming/ ideation and sketching. When prompted to discuss these non-salient parameters (from the student perspective) in the final design report, student design teams often used a post-hoc justification to support how the final designs fit the parameters that they did not initially consider. CONCLUSIONS This study suggests is that student design teams become fixated on (and consequently prioritize) certain parameters they interpret as important because they feel these parameters were described more explicitly in terms how they were met and assessed. Students fail to consider other parameters, perceived to be less directly assessable, unless prompted to do so. Failure to consider other parameters in the early design phases subsequently affects their approach in design phases as well. Case studies examining students’ study strategies within three Australian Universities illustrate similarities with some student approaches to design.

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The role of material artefacts in supporting distributed and co-located work practices has been well acknowledged within HCI and CSCW research. In this paper, we show that in addition to their ecological, coordinative and organizational support, artefacts also play an 'experiential' role. In this case, artefacts not only improve efficiency or have a purely functional role (e.g. allowing people to complete tasks quickly), but the materiality, use and manifestations of these artefacts bring quality and richness to people's performance and help them make better sense of their everyday lives. In a domain such as industrial design, such artefacts play an important role for supporting creativity and innovation. Based on our ethnographic fieldwork on understanding cooperative design practices of industrial design students and researchers, we describe several experiential practices that are supported by design-related artefacts such as sketches, drawings, physical models and explorative prototypes -- used and developed in designers' everyday work. Our main intention in carrying out this kind of research is to develop technologies to support designers' everyday practices. We believe that with the emergence of ubiquitous computing, there is a growing need to focus on the personal, social and creative side of people's everyday experiences. By focusing on the experiential practices of designers, we can provide a much broader view in the design of new interactive technologies.

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In this paper, we address the control design problem of positioning of over-actuated marine vehicles with control allocation. The proposed design is based on a combined position and velocity loops in a multi-variable anti-windup implementation together with a control allocation mapping. The vehicle modelling is considered with appropriate simplifications related to low-speed manoeuvring hydrodynamics and vehicle symmetry. The control design is considered together with a control allocation mapping. We derive analytical tuning rules based on requirements of closed-loop stability and performance. The anti- windup implementation of the controller is obtained by mapping the actuator-force constraint set into a constraint set for the generalized forces. This approach ensures that actuation capacity is not violated by constraining the generalized control forces; thus, the control allocation is simplified since it can be formulated as an unconstrained problem. The mapping can also be modified on-line based on actuator availability to provide actuator-failure accommodation. We provide a proof of the closed-loop stability and illustrate the performance using simulation scenarios for an open-frame underwater vehicle.

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Designing systems for multiple stakeholders requires frequent collaboration with multiple stakeholders from the start. In many cases at least some stakeholders lack a professional habit of formal modeling. We report observations from student design teams as well as two case studies, respectively of a prototype for supporting creative communication to design objects, and of stakeholder-involvement in early design. In all observations and case studies we found that non-formal techniques supported strong collaboration resulting in deep understanding of early design ideas, of their value and of the feasibility of solutions.

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In this paper, we address the control design problem of positioning of over-actuated underwater vehicles. The proposed design is based on a control architecture with combined position and velocity loops and a control tuning method based on the decoupled models. We derive analytical tuning rules based on requirements of closed-loop stability, positioning performance, and the vehicle velocity dynamic characteristics. The vehicle modelling is considered from force to motion with appropriate simplifications related to low-speed manoeuvring hydrodynamics and vehicle symmetry. The control design is considered together with a control allocation mapping. This approach makes the control tuning independent of the characteristics of the force actuators and provides the basis for control reconfiguration in the presence of actuator failure. We propose an anti-wind-up implementation of the controller, which ensures that the constraints related to actuation capacity are not violated. This approach simplifies the control allocation problem since the actuator constraints are mapped into generalised force constraints.

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A robust and reliable grid power interface system for wind turbines using a permanent-magnet synchronous generator (PMSG) is proposed in this paper, where an integration of a generator-side three-switch buck-type rectifier and a grid-side Z-source inverter is employed as a bridge between the generator and the grid. The modulation strategy for the proposed topology is developed from space-vector modulation and Z-source network operation principles. Two PMSG control methods, namely, unity-power-factor control and rotor-flux-orientation control (Id = 0), are studied to establish an optimized control scheme for the generator-side three-switch buck-type rectifier. The system control scheme decouples active- and reactive-power control through voltage-oriented control and optimizes PMSG control for the grid- and generator-side converters independently. Maximum power point tracking is implemented by adjusting the shoot-through duty cycles of the Z-source network. The design considerations of the passive components are also provided. The performances and practicalities of the designed architecture have been verified by simulations and experiments.