850,769 research outputs found

    The Lunar Environment

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    The NASA lunar exploration program has focused the attention of many scientific and technical groups on such questions as the relative value of lunar experiments, the advantages of manned versus unmanned exploration, and the proper time sequence for the steps to be taken in the exploration program. It is interesting to note that all the approaches to the problem require a definition of the lunar environment at an early stage in the program. The choice of scientific experiments and the design of the required instrumentation is based on our present knowledge of the Moon and on educated guesses as to what data may be obtained. The technical developments required to make possible both a lunar landing and continued operation of scientific equipment on the lunar surface also demand a definition of the lunar environment as a design condition

    Exploring Design Dimensions in Flash-based Mass-memory Devices

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    Mission-critical space system applications present several issues: a typical one is the design of a mass-memory device (i.e., a solid- state recorder). This goal could be accomplished by using flash- memories: the exploration of a huge number of parameters and trade-offs is needed. On the one hand flash-memories are nonvolatile, shock-resistant and power-economic, but on the other hand their cost is higher than normal hard disk, the number of erasure cycles is bounded and other different drawbacks have to be considered. In addition space environment presents various issues especially because of radiations: the design of a flash- memory based solid-state recorder implies the exploration of different and quite often contrasting dimensions. No systematic approach has so far been proposed to consider them all as a whole: as a consequence the design of flash-based mass-memory device for space applications is intended to be supported by a novel design environment currently under development and refinemen

    Requirements Problem and Solution Concepts for Adaptive Systems Engineering, and their Relationship to Mathematical Optimisation, Decision Analysis, and Expected Utility Theory

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    Requirements Engineering (RE) focuses on eliciting, modelling, and analyzing the requirements and environment of a system-to-be in order to design its specification. The design of the specification, usually called the Requirements Problem (RP), is a complex problem solving task, as it involves, for each new system-to-be, the discovery and exploration of, and decision making in, new and ill-defined problem and solution spaces. The default RP in RE is to design a specification of the system-to-be which (i) is consistent with given requirements and conditions of its environment, and (ii) together with environment conditions satisfies requirements. This paper (i) shows that the Requirements Problem for Adaptive Systems (RPAS) is different from, and is not a subclass of the default RP, (ii) gives a formal definition of RPAS, and (iii) discusses implications for future research

    Orthogonal-Array based Design Methodology for Complex, Coupled Space Systems

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    The process of designing a complex system, formed by many elements and sub-elements interacting between each other, is usually completed at a system level and in the preliminary phases in two major steps: design-space exploration and optimization. In a classical approach, especially in a company environment, the two steps are usually performed together, by experts of the field inferring on major phenomena, making assumptions and doing some trial-and-error runs on the available mathematical models. To support designers and decision makers during the design phases of this kind of complex systems, and to enable early discovery of emergent behaviours arising from interactions between the various elements being designed, the authors implemented a parametric methodology for the design-space exploration and optimization. The parametric technique is based on the utilization of a particular type of matrix design of experiments, the orthogonal arrays. Through successive design iterations with orthogonal arrays, the optimal solution is reached with a reduced effort if compared to more computationally-intense techniques, providing sensitivity and robustness information. The paper describes the design methodology in detail providing an application example that is the design of a human mission to support a lunar base

    Re-imaging the Environment

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    This paper represents a study of selected visualisation and investigative methods that facilitate the exploration and expression of human emotions and perceptions within real world environments during the design development stages of a project, repositioning exploration and visualisation in spatial design education. It puts forward an outline for an iterative enquiry around human experiences in order to assess the value of alternative cognitive tools for spatial design students in higher education. Established tools such as orthographic drawings, axonometric projections or scale models equip spatial designers with the consistency they need to investigate and represent physical attributes of space but don't always constitute the best methods to explore the perceived environment, even though it is a key contributing factor to the way we experience our surroundings. It is therefore in the interest of design educators to investigate complementary interpretations that enable students to consciously explore less tangible aspects of design such as emotions and multi-sensorial modalities. Projects developed using tools and techniques ranging from digital 2D and 3D image making, photography, film, animation and performance provide an insight into the possibilities offered by exisiting visual technologies as dynamic study devices of human experiences and contribute to the generation of alternative processes in spatial design education

    Analysis and Simulation of the Leg of an Hexapod Robot for Remote Exploration

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    The locomotion system is determined by the terrain conditions. The aim of this paper is to introduce the characteristics and simulation of a hexapod legged robot that can be easily used for exploration of abrupt and harsh terrains, Jike the Rio Tinto environment. A walking robot seems like the best option for this kind of terrain. Some of the advantages are that they do not need continuous terrain, they have less problems with sliding and they also have greater capacity to overcome obstacles as they produce Jess harm to the environment that the scientist wants to explore on the contrary when faced with mechanical design they present a design challenge, also in the static and dynamic analysis problem of a legged robot, there is a high complexity that has to be taken into account. This paper shows how to easily cope with the analysis of hexapod robot movement based on a design developed by the Center of Astrobiology INTA-CSIC for operation in RioTinto (Huelva - Spain)
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