共查询到20条相似文献,搜索用时 31 毫秒
1.
There is rapidly increasing interest in Location Based Service (LBS) which utilizes location data of moving objects. To efficiently
manage the huge amounts of location data in LBS, the GALIS (Gracefully Aging Location Information System) architecture, a
cluster-based distributed computing architecture, is proposed. The GALIS using the non-uniform 2-level grid algorithm performs
load balancing and indexing for nodes. However, the non-uniform 2-level grid algorithm has a problem creating unnecessary
nodes when moving objects are crowded in a certain region. Therefore, a new node split algorithm, which is more efficient
for various distribution of moving objects, is proposed in this paper. Because the algorithm proposed in this paper considers
spatial distribution for the current location of moving objects, it can perform efficient load balancing without creating
unnecessary nodes even when moving objects are congested in a certain region. Besides, the various data distribution configuration
for moving objects has been experimented by implementing node split simulators and it’s been verified that the proposed algorithm
can split nodes more efficiently than the existing algorithm.
相似文献
2.
We present a study of using camera-phones and visual-tags to access mobile services. Firstly, a user-experience study is described in which participants were both observed learning to interact with a prototype mobile service and interviewed
about their experiences. Secondly, a pointing-device task is presented in which quantitative data was gathered regarding the speed and accuracy with which participants aimed and clicked
on visual-tags using camera-phones. We found that participants’ attitudes to visual-tag-based applications were broadly positive,
although they had several important reservations about camera-phone technology more generally. Data from our pointing-device
task demonstrated that novice users were able to aim and click on visual-tags quickly (well under 3 s per pointing-device
trial on average) and accurately (almost all meeting our defined speed/accuracy tradeoff of 6% error-rate). Based on our findings,
design lessons for camera-phone and visual-tag applications are presented.
相似文献
3.
Irregular array redistribution has been paid attention recently since it can distribute different size of data segment to
heterogeneous processors according to their computational ability. It’s also the reason why it has been kept an eye on load
balance. High Performance Fortran Version 2 (HPF2) provides GEN_BLOCK distribution format which facilitates generalized block distributions. In this paper, we present a two-phase degree-reduction ( TPDR) method for scheduling HPF2 irregular array redistribution. Using a bipartite communication graph, the first phase of TPDR schedules communication links adjacent to processors that with degree greater than two. A communication step will be scheduled
follow each degree-reduction iteration. The second phase of TPDR schedules remaining messages of all processors that with degree-2 and degree-1 using an adjustable coloring mechanism. An
extended algorithm based on TPDR is also presented in this paper. Effectiveness of the proposed methods not only avoids node contention but also shortens
the overall communication cost. The proposed methods are also practicable due to low algorithmic complexity. To evaluate the
performance of our methods, we have implemented both algorithms along with the divide-and-conquer algorithm and two scheduling
mechanism. The simulation results show improvement of total communication costs.
相似文献
4.
Quantitative usability requirements are a critical but challenging, and hence an often neglected aspect of a usability engineering process. A case study is described where quantitative usability requirements played a key role in the development of a new user interface of a mobile phone. Within the practical constraints of the project, existing methods for determining usability requirements and evaluating the extent to which these are met, could not be applied as such, therefore tailored methods had to be developed. These methods and their applications are discussed. 相似文献
5.
An interconnection network architecture that promises to be an interesting option for future-generation parallel processing
systems is the OTIS (Optical Transpose Interconnection System) optoelectronic architecture. Therefore, all performance improvement
aspects of such a promising architecture need to be investigated; one of which is load balancing technique. This paper focuses
on devising an efficient algorithm for load balancing on the promising OTIS-Hypercube interconnection networks. The proposed
algorithm is called Clusters Dimension Exchange Method (CDEM). The analytical model and the experimental evaluation proved
the excellence of OTIS-Hypercube compared to Hypercube in terms of various parameters, including execution time, load balancing
accuracy, number of communication steps, and speed.
相似文献
6.
In this paper we propose a method to measure the semantic similarity of geographic classes organized as partition hierarchies
within Naive Geography. The contribution of this work consists in extending and integrating the information content approach, and the method for comparing concept attributes in the ontology management system SymOntos developed at IASI. As a result, this proposal allows us to address both the concept similarity within the partition hierarchy,
and the attribute similarity of geographic classes and, therefore, to reduce the gap among the different similarity approaches
defined in the literature.
相似文献
7.
We provide the complete record of methodology that let us evolve BrilliAnt, the winner of the Ant Wars contest. Ant Wars contestants are virtual ants collecting food on a grid board in the presence
of a competing ant. BrilliAnt has been evolved through a competitive one-population coevolution using genetic programming
and fitnessless selection. In this paper, we detail the evolutionary setup that lead to BrilliAnt’s emergence, assess its
direct and indirect human-competitiveness, and describe the behavioral patterns observed in its strategy.
相似文献
8.
We define a new mathematical model for the topological study of lattice height data. A discrete multivalued dynamical system
framework is used to establish discrete analogies of a Morse function, its gradient field, and its stable and unstable manifolds
in order to interpret functions numerically given on finite sets of pixels. We present efficient algorithms detecting critical
components of a height function f and displaying connections between them by means of a graph, called the Morse connections graph whose nodes represent the critical components of f and edges show the existence of connecting trajectories between nodes. This graph encodes efficiently the topological structure
of the data and makes it easy to manipulate for subsequent processing.
相似文献
9.
Ohne Zusammenfassung
相似文献
10.
Wealth distribution based on classic sugarscape model leads to a population increase and the Gini coefficient decrease when
cooperation and communication parameters are taken into account. In another study, this model was developed by implying a
receipt of one-fifth of the assets of the population and derived utilization for poor people. The results showed a relation
between mortality decrease, population increase, and Gini coefficient decrease (equality increase). In a synergic process,
the wealth adjustment based on sugarscape model underwent some experiments by implying communication and cooperation, and
the mechanism of receiving and utilizing the assets. The results show that the population increase and the Gini coefficient
decrease play an important role in wealth adjustment.
相似文献
11.
We give a brief overview of a logic-based symbolic modeling language PRISM which provides a unified approach to generative
probabilistic models including Bayesian networks, hidden Markov models and probabilistic context free grammars. We include
some experimental result with a probabilistic context free grammar extracted from the Penn Treebank. We also show EM learning
of a probabilistic context free graph grammar as an example of exploring a new area.
相似文献
12.
To get the maximum benefit from ambient intelligence (AmI), we need to anticipate and react to possible drawbacks and threats
emerging from the new technologies in order to devise appropriate safeguards. The SWAMI project took a precautionary approach
in its exploration of the privacy risks in AmI and sought ways to reduce them. It constructed four “dark scenarios” showing
possible negative implications of AmI, notably for privacy protection. Legal analysis of the depicted futures showed the shortcomings
of the current legal framework in being able to provide adequate privacy protection in the AmI environment. In this paper,
the authors, building upon their involvement in SWAMI research as well as the further advancement of EU privacy analysis,
identify various outstanding issues regarding the legal framework that still need to be resolved in order to deal with AmI
in an equitable and efficacious way. This article points out some of the lacunae in the legal framework and postulates several
privacy-specific safeguards aimed at overcoming them.
相似文献
13.
Indexing and segmenting of video content by motion, color and texture has been intensively explored leading to a commonly used representation in a storyboard. In this paper, a novel method of visualization of video content is proposed. First of all, the content is segmented into shots, and then a spatio-temporal color signature of shots, based on color distribution in the frames, is proposed. This spatio-temporal color signature serves as a basis for graph clustering and graph visualization tools. Those, integrated in a platform for visualization of huge graphs, Tulip, supply an exciting graph-based navigation interface for multimedia content. The results obtained on feature documentaries are promising. 相似文献
14.
This paper describes the simulated car racing competition that was arranged as part of the 2007 IEEE Congress on Evolutionary
Computation. Both the game that was used as the domain for the competition, the controllers submitted as entries to the competition
and its results are presented. With this paper, we hope to provide some insight into the efficacy of various computational
intelligence methods on a well-defined game task, as well as an example of one way of running a competition. In the process,
we provide a set of reference results for those who wish to use the simplerace game to benchmark their own algorithms. The paper is co-authored by the organizers and participants of the competition.
相似文献
15.
The European Union co-funded COMUNICAR (communication multimedia unit inside car) project designed and developed an integrated multimedia human–machine interface (HMI) able to manage a wide variety of driver information systems (from entertainment to safety). COMUNICAR proposed an innovative information provision paradigm, in which the on-vehicle HMI is able to tailor the delivery of the information in real time according to the actual driving context and the drivers workload. COMUNICAR adopted a user-centred design process involving an iterative development based on extensive user tests since the early phases of the project. This approach was particularly useful to define and improve the layout of the user interface and specify the rules that decide the scheduling and the modalities of the delivery of the information messages to the driver. This paper introduces the COMUNICAR concept and the user-centred flow of design. Then, a concrete case of user-test driven, iterative improvement of a systems functionality is presented. We also briefly describe two software tools that we have designed to enhance the development process in a user-centred perspective. Finally, the future evolution of the concept of smart and safe information scheduling is sketched and discussed. 相似文献
16.
Tracking location is challenging due to the numerous constraints of practical systems including, but not limited to global
cost, device volume and weight, scalability and accuracy; these constraints are typically more severe for systems that should
be wearable and used indoors. We investigate the use of wearable solar cells to track changing light conditions (a concept
that we named LuxTrace) as a source of user displacement and activity data. We evaluate constraints of this approach and present
results from an experimental validation of displacement and activity estimation. The results indicate that a distance estimation
accuracy of 21 cm (80% quantile) can be achieved. A simple method to combine LuxTrace with complementary absolute location
estimation methods is also presented. We apply carpet-like distributed RFID tags to demonstrate online learning of new lighting
environments.
相似文献
17.
The normalized cut is a popular graph partitioning measure for perceptual organization. Here, some approximate but explicit
expressions are derived for the probability density function, cumulative distribution function and the moments of the normalized
cut. A simple procedure is provided for computing the associated percentile points and hence the associated confidence intervals.
Finally, an application is illustrated.
相似文献
18.
Feasibility and schedulability problems have received considerable attention from the real-time systems research community
in recent decades. Since the publication of the Liu and Layland bound, many researchers have tried to improve the schedulability
bound of the RM scheduling. The LL bound does not make any assumption on the relationship between any of the task periods.
In this paper we consider the relative period ratios in a system. By reducing the difference between the smallest and the
second largest virtual period values in a system, we can show that the RM schedulability bound can be improved significantly.
This research has also proposed a system design methodology to improve the schedulability of real time system with a fixed
system load.
相似文献
19.
Peer-Peer (P2P) technologies have recently been in the limelight for their disruptive power in particular they have emerged as a powerful multimedia content distribution mechanism. However, the widespread deployment of P2P networks are hindered by several issues, especially the ones that influence end-user satisfaction, including reliability. In this paper, we propose a solution for an efficient and user-oriented keyword lookup service on P2P networks. The proposed mechanism has been designed to achieve reliability via index load balancing and address the scalability issues of extremely popular keywords in the index. The system performance have been analytically derived as well implemented using the OpenDHT framework on PlanetLab. 相似文献
20.
In this paper, we conduct an in-depth evaluation of a broad spectrum of scheduling alternatives for clusters. These include
the widely used batch scheduling, local scheduling, gang scheduling, most prior communication-driven coscheduling algorithms- Dynamic Coscheduling (DCS), Spin Block (SB), Periodic Boost (PB), and Co-ordinated Coscheduling (CC)-and a newly proposed HYBRID coscheduling algorithm on a 16-node, Myrinet-connected Linux cluster.
Performance and energy measurements using several NAS, LLNL and ANL benchmarks on the Linux cluster provide several conclusions.
First, although batch scheduling is currently used in most clusters, the blocking-based coscheduling techniques such as SB,
CC and HYBRID and the gang scheduling can provide much better performance even in a dedicated cluster platform. Second, in
contrast to some of the prior studies, we observe that blocking-based schemes like SB and HYBRID can provide better performance
than spin-based techniques like PB on a Linux platform. Third, the proposed HYBRID scheduling provides the best performance-energy
behavior and can be implemented on any cluster with little effort. All these results suggest that blocking-based coscheduling
techniques are viable candidates to be used in clusters for significant performance-energy benefits.
相似文献
|