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排序方式: 共有10000条查询结果,搜索用时 82 毫秒
991.
Tomás Sánchez López Damith C. Ranasinghe Mark Harrison Duncan McFarlane 《Personal and Ubiquitous Computing》2012,16(3):291-308
The Internet of Things (IoT) concept is being widely presented as the next revolution toward massively distributed information,
where any real-world object can automatically participate in the Internet and thus be globally discovered and queried. Despite
the consensus on the great potential of the concept and the significant progress in a number of enabling technologies, there
is a general lack of an integrated vision on how to realize it. This paper examines the technologies that will be fundamental
for realizing the IoT and proposes an architecture that integrates them into a single platform. The architecture introduces
the use of the Smart Object framework to encapsulate radio-frequency identification (RFID), sensor technologies, embedded
object logic, object ad-hoc networking, and Internet-based information infrastructure. We evaluate the architecture against
a number of energy-based performance measures, and also show that it outperforms existing industry standards in metrics such
as network throughput, delivery ratio, or routing distance. Finally, we demonstrate the feasibility and flexibility of the
architecture by detailing an implementation using Wireless Sensor Networks and Web Services, and describe a prototype for
the real-time monitoring of goods flowing through a supply chain. 相似文献
992.
We present a simple and efficient approach for continuous collision detection of deforming triangles based on conservative advancement. The efficiency of our approach is due to a sequence of simple collision-free conditions for deforming triangles. In our experiment, we show that our CCD algorithm achieves 2-30 times performance improvement over existing algorithms for triangle primitives. 相似文献
993.
Lee SH Park T Kim JH Kim CH 《IEEE transactions on visualization and computer graphics》2012,18(7):1135-1145
We address the computational resource requirements of 3D example-based synthesis with an adaptive synthesis technique that uses a tree-based synthesis map. A signed-distance field (SDF) is determined for the 3D exemplars, and then new models can be synthesized as SDFs by neighborhood matching. Unlike voxel synthesis approach, our input is posed in the real domain to preserve maximum detail. In comparison to straightforward extensions to the existing volume texture synthesis approach, we made several improvements in terms of memory requirements, computation times, and synthesis quality. The inherent parallelism in this method makes it suitable for a multicore CPU. Results show that computation times and memory requirements are very much reduced, and large synthesized scenes exhibit fine details which mimic the exemplars. 相似文献
994.
In this paper, we present an efficient way of implementing OpenGL ES 1.1 3D graphics API library for the environments with
hardware-supported OpenGL facility, typically as desktop PCs. Although OpenGL ES was started from the existing OpenGL features,
it rapidly became the standard 3D graphics library customized for embedded systems through introducing fixed-point arithmetic
operations, buffer management with fixed-point data type supports, completely new texture mapping functions and others. Currently,
it is the official 3D graphics API for Google Android, Apple iPhone, Sony PlayStation3, etc. In this paper, we achieved improvements
on the arithmetic operations for the fixed-point number representation, which is the most characteristic data type for OpenGL
ES 1.1. For the conversion of fixed-point data types to the floating-point number representations for the underlying OpenGL,
we show the way of efficient conversion processes even with satisfying OpenGL ES standard requirements. We also introduced
a specialized memory management scheme to manage the converted data from the buffer containing fixed-point numbers. In the
case of texture processing, the requirements in both standards are quite different, and thus we used completely new software-implementations.
Our final implementation of OpenGL ES library provides all of more than 200 functions in the standard specification and passed
its conformance test, to show its compliance with the standard. From the efficiency point of view, we measured its execution
times for several OpenGL ES-specific application programs and achieved remarkable improvements. 相似文献
995.
In this paper, we present AutoMed, an automated mediator for multi-issue bilateral negotiation under time constraints. AutoMed
elicits the negotiators preferences and analyzes them. It monitors the negotiations and proposes possible solutions for resolving
the conflict. We conducted experiments in a simulated environment. The results show that negotiations mediated by AutoMed
are concluded significantly faster than non-mediated ones and without any of the negotiators opting out. Furthermore, the
subjects in the mediated negotiations are more satisfied with the resolutions than the subjects in the non-mediated negotiations. 相似文献
996.
Jung-Ho Um Yong-Ki Kim Hyun-Jo Lee Miyoung Jang Jae-Woo Chang 《Journal of Systems Architecture》2012,58(9):354-371
Due to the advancement of wireless internet and mobile positioning technology, the application of location-based services (LBSs) has become popular for mobile users. Since users have to send their exact locations to obtain the service, it may lead to several privacy threats. To solve this problem, a cloaking method has been proposed to blur users’ exact locations into a cloaked spatial region with a required privacy threshold (k). With the cloaked region, an LBS server can carry out a k-nearest neighbor (k-NN) search algorithm. Some recent studies have proposed methods to search k-nearest POIs while protecting a user’s privacy. However, they have at least one major problem, such as inefficiency on query processing or low precision of retrieved result. To resolve these problems, in this paper, we propose a novel k-NN query processing algorithm for a cloaking region to satisfy both requirements of fast query processing time and high precision of the retrieved result. To achieve fast query processing time, we propose a new pruning technique based on a 2D-coodinate scheme. In addition, we make use of a Voronoi diagram for retrieving the nearest POIs efficiently. To satisfy the requirement of high precision of the retrieved result, we guarantee that our k-NN query processing algorithm always contains the exact set of k nearest neighbors. Our performance analysis shows that our algorithm achieves better performance in terms of query processing time and the number of candidate POIs compared with other algorithms. 相似文献
997.
In this paper, we present a formulation of the quaternion constraint for rigid body rotations in the form of a standard perfect
bilateral mechanical constraint, for which the associated Lagrangian multiplier has the meaning of a constraint force. First,
the equations of motion of a scalable body are derived. A scalable body has three translational, three rotational, and one
uniform scaling degree of freedom. As generalized coordinates, an unconstrained quaternion and a displacement vector are used.
To the scalable body, a perfect bilateral constraint is added, restricting the quaternion to unit length and making the body
rigid. This way a quaternion based differential algebraic equation (DAE) formulation for the dynamics of a rigid body is obtained,
where the 7×7 mass matrix is regular and the unit length restriction of the quaternion is enforced by a mechanical constraint.
Finally, the equations of motion in the form of a DAE are linked to the Newton–Euler equations of motion of a rigid body.
The rigid body DAE formulation is useful for the construction of (energy) consistent integrators. 相似文献
998.
Bettina Berendt 《Data mining and knowledge discovery》2012,24(3):697-737
Over the last decade, privacy has been widely recognised as one of the major problems of data collections in general and the
Web in particular. This concerns specifically data arising from Web usage (such as querying or transacting) and social networking
(characterised by rich self-profiling including relational information) and the inferences drawn from them. The data mining
community has been very conscious of these issues and has addressed in particular the inference problems through various methods
for “privacy-preserving data mining” and “privacy-preserving data publishing”. However, it appears that these approaches by
themselves cannot effectively solve the privacy problems posed by mining. We argue that this is due to the underlying notions
of privacy and of data mining, both of which are too narrow. Drawing on notions of privacy not only as hiding, but as control
and negotiation, as well as on data mining not only as modelling, but as the whole cycle of knowledge discovery, we offer
an alternative view. This is intended to be a comprehensive view of the privacy challenges as well as solution approaches
along all phases of the knowledge discovery cycle. The paper thus combines a survey with an outline of an agenda for a comprehensive,
interdisciplinary view of Web mining and privacy. 相似文献
999.
Efficient compression and network adaptive video coding for distributed video surveillance 总被引:1,自引:1,他引:0
The availability of cheap network based video cameras and the prevalence of wireless networks has lead to a major thrust towards
deployment of large scale Distributed Video Surveillance (DVS) systems. This has opened up an important area of research to
deal with the issues involved in DVS system for efficient collection and transmission of large scale video streams from the
cameras at the guarded sites, to the end users in possibly constrained network conditions. In this paper, we propose a framework
based on content-based video classification and scalable compression scheme to provide a robust bandwidth efficient video
transmission for DVS. The scheme builds on a Discrete Wavelet Transform (DWT) based Color-Set Partitioning for Hierarchical
Trees (CSPIHT) coding to obtain a scalable bitstream. Wavelet domain segmentation and compression assists in development of
a DVS architecture. The architecture includes a novel module for dynamic allocation of Network bandwidth based on the current
available resources and constraints. Different frame constituents are optimally coded based on their relative significance,
perceptual quality, and available estimate of network bandwidth. Experimental result over different video sequences and simulations
for Network conditions demonstrate the efficient performance of the approach. 相似文献
1000.
Guang-Ho Cha 《Multimedia Tools and Applications》2012,56(2):351-364
One of the central problems regarding media search is the semantic gap between the low-level features computed automatically
from media data and the human interpretation of them. This is because the notion of similarity is usually based on high-level
abstraction but the low-level features do not sometimes reflect the human perception. In this paper, we assume the semantics
of media is determined by the contextual relationship in a dataset, and introduce the method to capture the contextual information from a large media (especially
image) dataset for effective search. Similarity search in an image database based on this contextual information shows encouraging
experimental results. 相似文献