912 resultados para Optics in computing
Resumo:
We show that, with suitable optics in the arm of a Michelson interferometer, orthogonal galvo-scanning mirrors build a sampling function in the form of Newton rings when the two interferometer arms are matched. Using a low-coherence source, one can obtain transversal depth-resolved images. A fast display procedure using a storage oscilloscope was devised based on this method.
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Mobile technology has been one of the major growth areas in computing over recent years (Urbaczewski, Valacich, & Jessup, 2003). Mobile devices are becoming increasingly diverse and are continuing to shrink in size and weight. Although this increases the portability of such devices, their usability tends to suffer. Fuelled almost entirely by lack of usability, users report high levels of frustration regarding interaction with mobile technologies (Venkatesh, Ramesh, & Massey, 2003). This will only worsen if interaction design for mobile technologies does not continue to receive increasing research attention. For the commercial benefit of mobility and mobile commerce (m-commerce) to be fully realized, users’ interaction experiences with mobile technology cannot be negative. To ensure this, it is imperative that we design the right types of mobile interaction (m-interaction); an important prerequisite for this is ensuring that users’ experience meets both their sensory and functional needs (Venkatesh, Ramesh, & Massey, 2003). Given the resource disparity between mobile and desktop technologies, successful electronic commerce (e-commerce) interface design and evaluation does not necessarily equate to successful m-commerce design and evaluation. It is, therefore, imperative that the specific needs of m-commerce are addressed–both in terms of design and evaluation. This chapter begins by exploring the complexities of designing interaction for mobile technology, highlighting the effect of context on the use of such technology. It then goes on to discuss how interaction design for mobile devices might evolve, introducing alternative interaction modalities that are likely to affect that future evolution. It is impossible, within a single chapter, to consider each and every potential mechanism for interacting with mobile technologies; to provide a forward-looking flavor of what might be possible, this chapter focuses on some more novel methods of interaction and does not, therefore, look at the typical keyboard and visual display-based interaction which, in essence, stem from the desktop interaction design paradigm. Finally, this chapter touches on issues associated with effective evaluation of m-interaction and mobile application designs. By highlighting some of the issues and possibilities for novel m-interaction design and evaluation, we hope that future designers will be encouraged to “think out of the box” in terms of their designs and evaluation strategies.
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In recent years, mobile technology has been one of the major growth areas in computing. Designing the user interface for mobile applications, however, is a very complex undertaking which is made even more challenging by the rapid technological developments in mobile hardware. Mobile human-computer interaction, unlike desktop-based interaction, must be cognizant of a variety of complex contextual factors affecting both users and technology. The Handbook of Research on User Interface Design and Evaluation provides students, researchers, educators, and practitioners with a compendium of research on the key issues surrounding the design and evaluation of mobile user interfaces, such as the physical environment and social context in which a mobile device is being used and the impact of multitasking behavior typically exhibited by mobile-device users. Compiling the expertise of over 150 leading experts from 26 countries, this exemplary reference tool will make an indispensable addition to every library collection.
Resumo:
We show that, with suitable optics in the arm of a Michelson interferometer, orthogonal galvo-scanning mirrors build a sampling function in the form of Newton rings when the two interferometer arms are matched. Using a low-coherence source, one can obtain transversal depth-resolved images. A fast display procedure using a storage oscilloscope was devised based on this method.
Resumo:
Mobile technologies have yet to be widely adopted by the Architectural, Engineering, and Construction (AEC) industry despite being one of the major growth areas in computing in recent years. This lack of uptake in the AEC industry is likely due, in large part, to the combination of small screen size and inappropriate interaction demands of current mobile technologies. This paper discusses the scope for multimodal interaction design with a specific focus on speech-based interaction to enhance the suitability of mobile technology use within the AEC industry by broadening the field data input capabilities of such technologies. To investigate the appropriateness of using multimodal technology for field data collection in the AEC industry, we have developed a prototype Multimodal Field Data Entry (MFDE) application. This application, which allows concrete testing technicians to record quality control data in the field, has been designed to support two different modalities of data input speech-based data entry and stylus-based data entry. To compare the effectiveness or usability of, and user preference for, the different input options, we have designed a comprehensive lab-based evaluation of the application. To appropriately reflect the anticipated context of use within the study design, careful consideration had to be given to the key elements of a construction site that would potentially influence a test technician's ability to use the input techniques. These considerations and the resultant evaluation design are discussed in detail in this paper.
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Many experts predicted that this, the first decade of the 21st century, will be the decade of mobile computing; although in recent years mobile technology has been one of the major growth areas in computing, the hype has thus far exceeded the reality (Urbaczewski, Valacich, & Jessup, 2003). Why is this? A recent international study of users of handheld devices suggests that there is a predominant perception that quality of service is low and that mobile applications are difficult to use; additionally, although users recognise the potential of emerging mobile technology, the study highlighted a general feeling that the technology is currently dominating rather than supporting users (Jarvenpaa, Lang, Takeda, & Tuunainen, 2003). Users are generally forgiving of physical limitations of mobile devices imposed by technological constraints; they are not, however, so forgiving of the interface to these devices (Sarker & Wells, 2003). Users can excuse restrictions on their use of mobile technology on the basis of level of technological advancement, but find it hard to accept impractical, illogical, or inconvenient interaction design.
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Mobile and wearable computers present input/output prob-lems due to limited screen space and interaction techniques. When mobile, users typically focus their visual attention on navigating their environment - making visually demanding interface designs hard to operate. This paper presents two multimodal interaction techniques designed to overcome these problems and allow truly mobile, 'eyes-free' device use. The first is a 3D audio radial pie menu that uses head gestures for selecting items. An evaluation of a range of different audio designs showed that egocentric sounds re-duced task completion time, perceived annoyance, and al-lowed users to walk closer to their preferred walking speed. The second is a sonically enhanced 2D gesture recognition system for use on a belt-mounted PDA. An evaluation of the system with and without audio feedback showed users' ges-tures were more accurate when dynamically guided by au-dio-feedback. These novel interaction techniques demon-strate effective alternatives to visual-centric interface de-signs on mobile devices.
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When faced with the task of designing and implementing a new self-aware and self-expressive computing system, researchers and practitioners need a set of guidelines on how to use the concepts and foundations developed in the Engineering Proprioception in Computing Systems (EPiCS) project. This report provides such guidelines on how to design self-aware and self-expressive computing systems in a principled way. We have documented different categories of self-awareness and self-expression level using architectural patterns. We have also documented common architectural primitives, their possible candidate techniques and attributes for architecting self-aware and self-expressive systems. Drawing on the knowledge obtained from the previous investigations, we proposed a pattern driven methodology for engineering self-aware and self-expressive systems to assist in utilising the patterns and primitives during design. The methodology contains detailed guidance to make decisions with respect to the possible design alternatives, providing a systematic way to build self-aware and self-expressive systems. Then, we qualitatively and quantitatively evaluated the methodology using two case studies. The results reveal that our pattern driven methodology covers the main aspects of engineering self-aware and self-expressive systems, and that the resulted systems perform significantly better than the non-self-aware systems.
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A spatial object consists of data assigned to points in a space. Spatial objects, such as memory states and three dimensional graphical scenes, are diverse and ubiquitous in computing. We develop a general theory of spatial objects by modelling abstract data types of spatial objects as topological algebras of functions. One useful algebra is that of continuous functions, with operations derived from operations on space and data, and equipped with the compact-open topology. Terms are used as abstract syntax for defining spatial objects and conditional equational specifications are used for reasoning. We pose a completeness problem: Given a selection of operations on spatial objects, do the terms approximate all the spatial objects to arbitrary accuracy? We give some general methods for solving the problem and consider their application to spatial objects with real number attributes. © 2011 British Computer Society.
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The 2008 National Student Survey revealed that: 44% of full-time students in England did not think that the feedback on their work had been prompt nor did they agree that the feedback on their work helped them clarify things that they did not understand (HEFCE, 2008). Computer Science and Engineering & Technology have been amongst the poorest performers in this aspect as they ranked in the lower quartile (Surridge, 2007, p.32). Five years since the first NSS survey, assessment and feedback remains the biggest concern. Dissatisfaction in any aspect of studies demotivates students and can lead to disengagement and attrition. As the student number grows, the situation can only get worse if nothing is done about it. We have conducted a survey to investigate views on assessment and feedback from Engineering, Mathematics and Computing students. The survey aims at investigating the core issues of dissatisfaction in assessment and feedback and ways in which UK Engineering students can learn better through helpful feedback. The study focuses on collecting students' experiences with feedback received in their coursework, assignments and quizzes in Computing Science modules. The survey reveals the role of feedback in their learning. The results of the survey help to identify the forms of feedback that are considered to be helpful in learning and the time frame for timely feedback. We report on the findings of the survey. We also explore ways to improve assessment and feedback in a bid to better engage engineering students in their studies.
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The Hong-Ou-Mandel (HOM) effect is widely regarded as the quintessential quantum interference phenomenon in optics. In this work we examine how nonlinearity can smear statistical photon bunching in the HOM interferometer. We model both the nonlinearity and a balanced beam splitter with a single two-level system and calculate a finite probability of anti-bunching arising in this geometry. We thus argue that the presence of such nonlinearity would reduce the visibility in the standard HOM setup, offering some explanation for the diminution of the HOM visibility observed in many experiments. We use the same model to show that the nonlinearity affects a resonant two-photon propagation through a two-level impurity in a waveguide due to a " weak photon blockade" caused by the impossibility of double-occupancy and argue that this effect might be stronger for multi-photon propagation.
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Welcome to the Second International Workshop on Multimedia Communications and Networking held in conjunction with IUCC-2012 during 25 June – 27 June 2012 in Liverpool, UK. MultiCom-2012 is dedicated to address the challenges in the areas of elivering multimedia content using modern communication and networking techniques. The multimedia & networking computing domain emerges from the integration of multimedia content such as audio and video with content distribution technologies. This workshop aims to cover contributions in both design and analysis aspects in the context of multimedia, wired/wireless/heterogeneous networks, and quality evaluation. It also intends to bring together researchers and practitioners from academia and industry to share their latest achievements in this field with others and establish new collaborations for future developments. All papers received are peer reviewed by three members of the Technical Programme Committee. The papers are assessed by their originality, technical quality, presentation and relevance to the theme of the workshop. Based on the criteria set, four papers have been accepted for presentation at the workshop and will appear in the IUCC conference proceedings. We would like to take this opportunity to thank the IUCC-2012 Organizing Committee, the TPC members of MultiCom-2012 and the authors for their s upport, dedicated work and contributions. Finally, we look forward to meeting you at the workshop in Liverpool.
Resumo:
A társadalombiztosítási nyugdíjrendszer finanszírozása pusztán a demográfiai folyamatok következtében is jelentős terhet ró majd a költségvetésére, amin a különböző parametrikus és paradigmatikus nyugdíjreformok enyhíthetnek. A reformok azonban hosszú távon olyan viselkedési, munkakínálati reakciókat válthatnak ki, amelyek alapvetően változtatják meg a költségvetési hatásokat. Az 1999 és 2009 között Magyarországon megfigyelhető átlagos munka- és nyugdíjkorprofilok bemutatása után arra tettünk kísérletet, hogy mikroökonómiai alapon határozzuk meg néhány alapvető parametrikus nyugdíjreformnak a férfiak életciklus-munkakínálatára gyakorolt hatását. A modell paramétereit a magyar gazdaság 1999 és 2009 közötti jellemzőinek megfelelően kalibráltuk. Eredményeink szerint a helyettesítési ráta csökkentése, a nyugdíjkorhatár emelése és a svájci indexálás árindexálásra cserélése összességében számottevően növeli az egyes képzettségi csoportok munkakínálatát, s a fiatalabb korosztályok javára csoportosítja át az életciklus-munkakínálatot, míg a nyugdíj kiszámításához figyelembe vett évek számának megváltoztatása nem hoz jelentős aggregált hatást, és nem jár a munkakínálat korcsoportok közötti átcsoportosításával. ____ Financing the social-security pension system will weigh heavily on the government budget in developed countries, merely through the projected demographic processes. The burden could be eased by various parametric and paradigmatic pension reforms, but in the long run such reforms may trigger behavioural, labour-supply responses, which may alter the budgetary effects fundamentally. Having described the average work and pension profiles in Hungary between 1999 and 2009, the authors use a microeconomic approach in an attempt to assess the effect of certain parametric pension reforms on the life-cycle labour supply of males. The parameters for the model were calibrated for the characteristics of the Hungarian economy. The results show that decreasing the replacement rate, increasing the retirement age and replacing Swiss indexation of pensions by price indexation cause a considerable increase in the labour supply of all education-level groups, whereas changing the number of years considered in computing pensions does not have a significant aggregate effect. While introducing price indexation increases the labour supply of all cohorts by the same amount, the other reforms reallocate the life-cycle labour supply, mainly towards younger age-groups.
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Due to the rapid advances in computing and sensing technologies, enormous amounts of data are being generated everyday in various applications. The integration of data mining and data visualization has been widely used to analyze these massive and complex data sets to discover hidden patterns. For both data mining and visualization to be effective, it is important to include the visualization techniques in the mining process and to generate the discovered patterns for a more comprehensive visual view. In this dissertation, four related problems: dimensionality reduction for visualizing high dimensional datasets, visualization-based clustering evaluation, interactive document mining, and multiple clusterings exploration are studied to explore the integration of data mining and data visualization. In particular, we 1) propose an efficient feature selection method (reliefF + mRMR) for preprocessing high dimensional datasets; 2) present DClusterE to integrate cluster validation with user interaction and provide rich visualization tools for users to examine document clustering results from multiple perspectives; 3) design two interactive document summarization systems to involve users efforts and generate customized summaries from 2D sentence layouts; and 4) propose a new framework which organizes the different input clusterings into a hierarchical tree structure and allows for interactive exploration of multiple clustering solutions.
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Buildings and other infrastructures located in the coastal regions of the US have a higher level of wind vulnerability. Reducing the increasing property losses and causalities associated with severe windstorms has been the central research focus of the wind engineering community. The present wind engineering toolbox consists of building codes and standards, laboratory experiments, and field measurements. The American Society of Civil Engineers (ASCE) 7 standard provides wind loads only for buildings with common shapes. For complex cases it refers to physical modeling. Although this option can be economically viable for large projects, it is not cost-effective for low-rise residential houses. To circumvent these limitations, a numerical approach based on the techniques of Computational Fluid Dynamics (CFD) has been developed. The recent advance in computing technology and significant developments in turbulence modeling is making numerical evaluation of wind effects a more affordable approach. The present study targeted those cases that are not addressed by the standards. These include wind loads on complex roofs for low-rise buildings, aerodynamics of tall buildings, and effects of complex surrounding buildings. Among all the turbulence models investigated, the large eddy simulation (LES) model performed the best in predicting wind loads. The application of a spatially evolving time-dependent wind velocity field with the relevant turbulence structures at the inlet boundaries was found to be essential. All the results were compared and validated with experimental data. The study also revealed CFD's unique flow visualization and aerodynamic data generation capabilities along with a better understanding of the complex three-dimensional aerodynamics of wind-structure interactions. With the proper modeling that realistically represents the actual turbulent atmospheric boundary layer flow, CFD can offer an economical alternative to the existing wind engineering tools. CFD's easy accessibility is expected to transform the practice of structural design for wind, resulting in more wind-resilient and sustainable systems by encouraging optimal aerodynamic and sustainable structural/building design. Thus, this method will help ensure public safety and reduce economic losses due to wind perils.