共查询到20条相似文献,搜索用时 10 毫秒
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Testing multimodal applications with visually impaired children requires specific testing methods and procedures. In this article, we used a SensAble Phantom device to produce haptic feedback together with stereo sound and visual feedback. We also experimented with low-cost haptic devices, such as force-feedback game controllers and tactile-feedback devices. Here we discuss how to conduct usability testing for multimodal applications with visually impaired children. 相似文献
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Since the first television pictures were received from Telstar by aerial 1 at Goonhilly Down in Cornwall, commercial operation of satellite systems has dictated that the earth-space link must be maintained as consistently as possible. Any break in transmission or lowering of quality results in huge losses for the operator and as a result the performance of the antenna tracking system has received a great deal of attention. Recently a new technique, termed `electronic beam-squinting', has been developed to solve this problem both elegantly and economically. It is capable of a performance approaching that of the most expensive systems currently available for fixed earth stations and is also applicable to mobile terminals 相似文献
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Electronic warfare systems 总被引:2,自引:0,他引:2
Electronic warfare (EW) is an important capability that can advance desired military, diplomatic, and economic objectives or, conversely, impede undesired ones. In a military application, EW provides the means to counter, in all battle phases, hostile actions that involve the electromagnetic (EM) spectrum-from the beginning when enemy forces are mobilized for an attack, through to the final engagement. EW exploits the EM environment by sensing and analyzing an adversary's application of the spectrum and imposing appropriate countermeasures (CMs) to hostile spectrum use. EW sensors are one means by which the military gathers tactical intelligence from noncooperative forces. EW sensors, together with EW CMs, mitigate the effectiveness of an adversary's electrooptic/infrared, and radio frequency-controlled weapons. EW enhances the survivability of the host force through control and manipulation of the EM environment and denies or limits its use by an adversary. EM spectrum CMs to threat systems can be selectively applied on a time- and/or frequency-multiplexed basis so that host force use of the EM spectrum is uninhibited 相似文献
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Electronic payment systems 总被引:1,自引:0,他引:1
Trusted electronic payment systems are a key enabler for mass acceptance of electronic commerce over insecure networks such as the Internet. This paper classifies the currently available payment systems on the Internet, and looks at likely payment systems for the future. The need for micropayments is also discussed. 相似文献
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Wireless Networks - Objective of this study is to introduce a novel, low-cost intelligent social walking path support system for visually impaired students in a wide campus area, by employing... 相似文献
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《Vehicular Technology, IEEE Transactions on》1976,25(4):171-172
Specifications and related documentation dealing with design requirements for electronic equipment used in EMS systems are reviewed and relevant portions cataloged. Where appropriate specifications do not exist, criteria are suggested for the operational, environmental, and functional performance standards to be used for the equipment. 相似文献
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The characterization and design of photovoltaic systems is a difficult issue due to the variable operation atmospheric conditions. With this aim, simulators and measurement equipments have been proposed. However, most of them do not deal with real atmospheric conditions. This letter proposes an electronic device that first measures the real evolution of the I-V characteristic curves of photovoltaic modules and generators, and then physically emulates in real time these curves to test photovoltaic inverters. The device consists of a dc-dc converter, a microcontroller and a data storage unit. The two operation modes (emulation and measurement) are digitally driven by the microcontroller. The converter current is controlled by means of a variable-hysteresis control loop, whose reference is provided by the microcontroller. In addition, a digital voltage control loop is designed to find out the complete characteristic curves of the photovoltaic generators. A 15-kW prototype is designed and built that can measure three times per second the characteristic curves of up to seven generators and then emulate their electrical behavior to test photovoltaic inverters. With the proposed device, the optimal configuration and performance of photovoltaic modules and generators, as well as the operation of photovoltaic inverters can be thoroughly analyzed under real atmospheric conditions. 相似文献
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Insects are the most successful group of living things in terms of the number of species, the biomass and their distribution. Entomological research has revealed that the insect sensory systems are crucial for their success. Compared to human brains, the insect central nerve systems are extremely primitive and simple, both structurally and functionally, and are of minimal learning ability. Faced with these constraints, insects have evolved a set of extremely effective sensory systems that are structurally simple, functionally versatile and powerful, and highly distributed, as well as noise and fault tolerant. As a result, in recent years insect sensory systems have been inspirational to new communications and computing paradigms, which have lead to significant advances. However, we believe that the potential for insect-inspired solutions for communications and computing is far from being fully recognized. In particular, the contrasting similarity between the ubiquitous existences of insect sensory networks in nature and the idea of pervasive computing has received little attention. For example, the chemosensory communication systems in many of the moth, ant and beetle populations are essentially “wireless” sensory networks. The difference between the “wireless” network of an insect population and an engineered wireless sensor network is that insects encode messages with semiochemicals (also known as infochemicals) rather than with radio frequencies; in addition, the computing node is the individual insect powered by its brain, sensory and neuromotor systems, rather than a microchip-powered sensor. The objectives of this paper are threefold: (1) to introduce the state-of-the art research in insect sensory systems from entomological perspectives; (2) to propose potential new research problems inspired by insect sensory system with focusing on unexplored fields; and (3) to justify how and why insect sensory systems may inspire novel computing and communications paradigms. 相似文献
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The purpose of this article is to demonstrate new paradigms in the analysis and design of virtual instrumentation in autonomous sensor systems. By autonomous sensor systems we mean mobile as well as immobile systems that employ a vast array of sensors to analyze or influence dynamic and uncertain external changes. These systems must perform operations in real time, in both expected and unexpected situations, using only limited human intervention. An autonomous sensor system can be used to collect data about a complex and dynamic environment, to perform interpretation and fusion of this data, and to present the resulting information to a human operator in a synthetic form that highlights features of interest of the environment. The system can then be regarded as a virtual instrument. A useful form to organize and present this information is a virtual spatial map-a representation of the environment in which colored geometric figures are placed to indicate that a given feature (or event) has been detected at that location. We illustrate our approach of building virtual instruments by presenting a case study of semi-autonomous remote environmental exploration. A mobile platform gathers information about a remote environment using multi-modal sensor data collection, information processing, and data fusion at different levels of abstraction and resolution. The result of the exploration is a fused virtual map that contains the important features of the environment 相似文献
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Roche J.R. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2002,48(6):1379-1392
We obtain asymptotically tight bounds on the maximum amount of information that a single bit of memory can retain about the entire past. At each of n successive epochs, a single fair bit is generated and a one-bit memory is updated according to a family of memory update rules (possibly probabilistic and time-dependent) depending only on the value of the new input bit and on the current state of the memory. The problem is to estimate the supremum over all possible update rules of the minimum mutual information between the state of the memory at time (n + 1) and each of the previous n input bits. We show that this supremum is asymptotically equal to 1/(2n2 ln 2) bit, as conjectured by Venkatesh and Franklin (1991). We use this result to derive asymptotically sharp estimates of related maximin correlations between the memory and the input bits, thus resolving two more questions left open by Venkatesh and Franklin and by Komlos et al. (1993). Finally, we generalize the results to the case of an m-bit memory, again obtaining asymptotically tight bounds in many cases 相似文献
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The required frequency spacings between channels in an optical frequency division multiplexing (FDM) network are considered. The minimum permissible spacings consistent with meeting bit error rate (BER) objectives are derived. The assumed transmission uses on-off keying (OOK), at a data rate 1/T (in bits per second), via external modulation of a laser source having linewidth β (in hertz). The assumed receiver consists of an optical channel selection filter followed by a p-i-n photodiode and a postdetection integrate-and-dump circuit. The analysis estimates the adjacent channel interference (ACI)-induced floor on BER for the middle of three FDM channels, as a function of frequency spacing and linewidth-to-bit rate ratio (βT ). For BER=10-9 and βT ranging from 0.32 to 5.12, the required channel spacing ranges from 5.2 to 27.5 bit rates. The multiplying factors associated with using (wide-deviation) frequency shift keying (FSK), coherent (heterodyne) detection, and infinitely many FDM channels, respectively, are estimated to be 2.0, at most 3.0, and at most 1.37 相似文献
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As we strive to advance in our jobs, our disposable time decreases. We're becoming time impaired in spite of our hunger for content. We don't have time to get the information we want. We have even less time to access the entertainment we want-at least in the old-fashioned way. Now that digital TV channels, digital video disks (DVD), and digital video home systems (DVHS) can feed our hunger for content, we need a drastic twist in the way we think of TV. We're used to the idea of displayable video and viewable TV. However, in the future we'll have to create searchable TV-similar to the concept of searchable databases. Searching on the fly, or content filtering, should enable applications such as parental control systems, commercial detection software, and selective news services while providing personalized TV experiences 相似文献
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This study presents a novel and highly efficient superpixel algorithm, namely, depth-fused adaptive superpixel (DFASP), which can generate accurate superpixels in a degraded image. In many applications, particularly in actual scenes, vision degradation, such as motion blur, overexposure, and underexposure, often occurs. Well-known color-based superpixel algorithms are incapable of producing accurate superpixels in degraded images because of the ambiguity of color information caused by vision degradation. To eliminate this ambiguity, we use depth and color information to generate superpixels. We map the depth and color information to a high-dimensional feature space. Then, we develop a fast multilevel clustering algorithm to produce superpixels. Furthermore, we design an adaptive mechanism to adjust the color and depth information automatically during pixel clustering. Experimental results demonstrate that regardless of boundary recall, under segmentation error, run time, or achievable segmentation accuracy, DFASP is better than state-of-the-art superpixel methods. 相似文献
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We present a video-based, contact-free measurement system which allows combined tracking of the subject's eye positions and the gaze direction in near real time. This system will be integrated into a new kind of autostereoscopic display which supports the natural link between accommodation and convergence of human vision, reproduces the limited depth of focus of human vision and shows comfortable, hologram-like scenes with motion parallax to subjects. 相似文献
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Electronic retina is a combination between in situ signal processing and image sensing on a same silicon chip. This smart image sensing, realizable in commoncmos technology, is a valuable technique in real-time vision systems. In order optimize the global performance of a vision machine where different levels of processing are needed, this technique can not be considered simply as an intelligent image sensor design problem. Because the local onsensor information processing in an electronic retina should be placed in a more general context including algorithms, architectures and applications. This paper tries to give an overview on the electronic retina based vision systems and especially on the roles that an electronic retina can play in real-time vision systems. 相似文献
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电子设备的整体结构形式不仅影响产品的可靠性与美观性,而且还影响冷却系统的合理性与有效性。主要介绍采用强迫通风制冷方法对电子设备进行冷却时,结构因素对风冷效果的影响。 相似文献
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A simple electronic measuring cup for the blind is described. It uses an array of infrared level detectors, which are immersed in the medium to be measured. When used with a standard 1-liter glass, the filling level is indicated acoustically in increments of 50 ml. 相似文献