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991.
Smart Cars on Smart Roads: An IEEE Intelligent Transportation Systems Society Update 总被引:1,自引:0,他引:1
Fei-Yue Wang Daniel Zeng Liuqing Yang 《Pervasive Computing, IEEE》2006,5(4):68-69
To promote tighter collaboration between the IEEE Intelligent Transportation Systems Society and the pervasive computing research community, the authors introduce the ITS Society and present several pervasive computing-related research topics that ITS Society researchers are working on. This department is part of a special issue on Intelligent Transportation. 相似文献
992.
Free viewpoint action recognition using motion history volumes 总被引:5,自引:0,他引:5
Daniel Weinland Remi Ronfard Edmond Boyer 《Computer Vision and Image Understanding》2006,104(2-3):249
Action recognition is an important and challenging topic in computer vision, with many important applications including video surveillance, automated cinematography and understanding of social interaction. Yet, most current work in gesture or action interpretation remains rooted in view-dependent representations. This paper introduces Motion History Volumes (MHV) as a free-viewpoint representation for human actions in the case of multiple calibrated, and background-subtracted, video cameras. We present algorithms for computing, aligning and comparing MHVs of different actions performed by different people in a variety of viewpoints. Alignment and comparisons are performed efficiently using Fourier transforms in cylindrical coordinates around the vertical axis. Results indicate that this representation can be used to learn and recognize basic human action classes, independently of gender, body size and viewpoint. 相似文献
993.
The normalization of a data cube is the ordering of the attribute values. For large multidimensional arrays where dense and sparse chunks are stored differently, proper normalization can lead to improved storage efficiency. We show that it is NP-hard to compute an optimal normalization even for 1 × 3 chunks, although we find an exact algorithm for 1 × 2 chunks. When dimensions are nearly statistically independent, we show that dimension-wise attribute frequency sorting is an optimal normalization and takes time O(dn log(n)) for data cubes of size nd. When dimensions are not independent, we propose and evaluate a several heuristics. The hybrid OLAP (HOLAP) storage mechanism is already 19-30% more efficient than ROLAP, but normalization can improve it further by 9-13% for a total gain of 29-44% over ROLAP. 相似文献
994.
A Taxonomy and Evaluation of Dense Two-Frame Stereo Correspondence Algorithms 总被引:104,自引:9,他引:104
Stereo matching is one of the most active research areas in computer vision. While a large number of algorithms for stereo correspondence have been developed, relatively little work has been done on characterizing their performance. In this paper, we present a taxonomy of dense, two-frame stereo methods. Our taxonomy is designed to assess the different components and design decisions made in individual stereo algorithms. Using this taxonomy, we compare existing stereo methods and present experiments evaluating the performance of many different variants. In order to establish a common software platform and a collection of data sets for easy evaluation, we have designed a stand-alone, flexible C++ implementation that enables the evaluation of individual components and that can easily be extended to include new algorithms. We have also produced several new multi-frame stereo data sets with ground truth and are making both the code and data sets available on the Web. Finally, we include a comparative evaluation of a large set of today's best-performing stereo algorithms. 相似文献
995.
One of the persistently exciting control applications is that of disk drive servos. From the start in the early 1950s to the massive capacity commodity drives of the early 2000s, the problem of accessing data on rotating disk media has provided a wealth of control challenges to be solved. This survey paper traces the early history of disk drive control from the first disk drive in 1956 to the first commercial drive with Magneto-Resistive heads in 1990. Rather than the approach used in (Abramovitch and Franklin, 2002a) in which the histories of the components were outlined first, we will focus on the feedback loop itself in those early days. The paper will survey the different areas of the disk drive control problem and how they evolved. 相似文献
996.
We present a formula for the extremes of the null controllable region of a general LTI discrete-time system with bounded inputs. For an nth order system with only real poles (not necessarily distinct), the formula is simplified to an elementary matrix function, which in turn shows that the set of the extremes coincides with a set of trajectories of the time-reversed system under bang-bang controls with n−2 or less switches. 相似文献
997.
Daniel M. Reeves Michael P. Wellman & Benjamin N. Grosof 《Computational Intelligence》2002,18(4):482-500
Our approach for automating the negotiation of business contracts proceeds in three broad steps. First, determine the structure of the negotiation process by applying general knowledge about auctions and domain–specific knowledge about the contract subject along with preferences from potential buyers and sellers. Second, translate the determined negotiation structure into an operational specification for an auction platform. Third, after the negotiation has completed, map the negotiation results to a final contract. We have implemented a prototype which supports these steps by employing a declarative specification (in courteous logic programs) of (1) high–level knowledge about alternative negotiation structures, (2) general–case rules about auction parameters, (3) rules to map the auction parameters to a specific auction platform, and (4) special–case rules for subject domains. We demonstrate the flexibility of this approach by automatically generating several alternative negotiation structures for the domain of travel shopping in a trading agent competition. 相似文献
998.
Development of a robust two-way real-time speech translationsystem exposes researchers and system developers to various challenges of machine translation(MT) and spoken language dialogues. The need for communicating in at least two differentlanguages poses problems not present for a monolingual spoken language dialogue system,where no MT engine is embedded within the process flow. Integration of various componentmodules for real-time operation poses challenges not present for text translation. In this paper,we present the CCLINC (Common Coalition Language System at Lincoln Laboratory) English–Koreantwo-way speech translation system prototype trained on doctor–patient dialogues,which integrates various techniques to tackle the challenges of automatic real-time speechtranslation. Key features of the system include (i) language–independent meaning representation which preserves the hierarchicalpredicate–argument structure of an input utterance, providing a powerful mechanism for discourse understanding of utterances originating from different languages,word-sense disambiguation and generation of various word orders of many languages, (ii) adoptionof the DARPA Communicator architecture, a plug-and-play distributed system architecturewhich facilitates integration of component modules and system operation in real time, and (iii)automatic acquisition of grammar rules and lexicons for easy porting of the system to differentlanguages and domains. We describe these features in detail and present experimental results. 相似文献
999.
Although fatty acid-binding proteins (FABP) differentially affect fatty acid uptake, nothing is known regarding their role(s)
in determining cellular phospholipid levels and phospholipid fatty acid composition. The effects of liver (L)- and intestinal
(I)-FABP expression on these parameters were determined using stably transfected L-cells. Expression of L- and I-FABP increased
cellular total phospholipid mass (nmol/mg protein) 1.7- and 1.3-fold relative to controls, respectively. L-FABP expression
increased the masses of choline glycerophospholipids (ChoGpl) 1.5-fold, phosphatidylserine (PtdSer) 5.6-fold, ethanolamine
glycerophospholipids 1.4-fold, sphingomyelin 1.7-fold, and phosphatidylinositol 2.6-fold. In contrast, I-FABP expression only
increased the masses of ChoGpl and PtdSer, 1.2- and 3.1-fold, respectively. Surprisingly, both L- and I-FABP expression increased
ethanolamine plasmalogen mass 1.6- and 1.1-fold, respectively, while choline plasmalogen mass was increased 2.3- and 1.7-fold,
respectively. The increase in phospholipid levels resulted in dramatic 48 and 33% decreases in the cholesterol-to-phospholipid
ratio in L- and I-FABP expressing cells, respectively. L-FABP expression generally increased polyunsaturated fatty acids,
primarily by increasing 20∶4n−6 and 22∶6n−3, while decreasing 18∶1n−9 and 16∶1n−7. I-FABP expression generally increased only
20∶4n−6 proportions. Hence, expression of both I- and L-FABP differentially affected phospholipid mass, class composition,
and acyl chain composition. Although both proteins enhanced phospholipid synthesis, the effect of L-FABP was much greater,
consistent with previous work suggesting that these two FABP differentially affect lipid metabolism. 相似文献
1000.
Sharon Daniel 《AI & Society》2000,14(2):196-213
This paper will discuss interactive on-line artworks modelled on cellular automata that employ various types of agents, both algorithmic and human, to assist in the evolution of their databases. These works constitute what will here be referred to as Collaborative Systems systems that evolve through the practice of inter-authorship. 相似文献