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1.
In the past decade, the number of mobile devices has increased significantly. These devices are in turn showing more computational
capabilities. It is therefore possible to envision a near future where client applications may be deployed on these devices.
There are, however, constraints that hinder this deployment, especially the limited communication bandwidth and storage space
available. This paper describes the Efficient XML Data Exchange Manager (EXEM) that combines context-dependent lossy and lossless
compression mechanisms used to support lightweight exchange of objects in XML format between server and client applications.
The lossy compression mechanism reduces the size of XML messages by using known information about the application. The lossless
compression mechanism decouples data and metadata (compression dictionary) content. We illustrate the use of EXEM with a prototype
implementation of the lossless compression mechanism that shows the optimization of the available resources on the server
and the mobile client. These experimental results demonstrate the efficiency of the EXEM approach for XML data exchange in
the context of mobile application development.
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2.
The compression of spatial data is a promising solution to reduce the space of data storage and to decrease the transmission
time of spatial data over the Internet. This paper proposes a new method for variable-resolution compression of vector data.
Three key steps are encompassed in the proposed method, namely, the simplification of vector data via the elimination of vertices,
the compression of removed vertices, and the decoding of the compressed vector data. The proposed compression method was implemented
and applied to compress vector data to investigate its performance in terms of the compression ratio, distortions of geometric
shapes. The results show that the proposed method provides a feasible and efficient solution for the compression of vector
data, is able to achieve good compression ratios and maintains the main shape characteristics of the spatial objects within
the compressed vector data.
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3.
Various techniques have been developed for different query types in content-based image retrieval systems such as sampling
queries, constrained sampling queries, multiple constrained sampling queries, k-NN queries, constrained k-NN queries, and multiple localized k-NN queries. In this paper, we propose a generalized query model suitable for expressing queries of different types, and investigate
efficient processing techniques for this new framework. We exploit sequential access and data sharing by developing new storage
and query processing techniques to leverage inter-query concurrency. Our experimental results, based on the Corel dataset,
indicate that the proposed optimization can significantly reduce average response time in a multiuser environment, and achieve
better retrieval precision and recall compared to two recent techniques.
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4.
Detecting and dealing with redundancy is an ubiquitous problem in query optimization, which manifests itself in many areas
of research such as materialized views, multi-query optimization, and query-containment algorithms. In this paper, we focus
on the issue of intra-query redundancy, redundancy present within a query. We present a method to detect the maximal redundancy present between a main (outer) query block and a subquery block.
We then use the method for query optimization, introducing query plans and a new operator that take full advantage of the
redundancy discovered. Our approach can deal with redundancy in a wider spectrum of queries than existing techniques. We show
experimental evidence that our approach works under certain conditions, and compares favorably to existing optimization techniques
when applicable.
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5.
Due to the increase of XML-based applications, XML schema design has become an important task. One approach is to consider
conceptual schemas as a basis for generating XML documents compliant to consensual information of specific domains. However,
the conversion of conceptual schemas to XML schemas is not a straightforward process and inconvenient design decisions can
lead to a poor query processing on XML documents generated. This paper presents a conversion approach which considers data
and query workload estimated for XML applications, in order to generate an XML schema from a conceptual schema. Load information
is used to produce XML schemas which can respond well to the main queries of an XML application. We evaluate our approach
through a case study carried out on a native XML database. The experimental results demonstrate that the XML schemas generated
by our methodology contribute to a better query performance than related approaches.
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6.
The article draws on a decade of work in the UK by the UK Work Organisation Network (UKWON), and recommends a systematic approach.
Taking cases in the National Health Service, the focus is on employee involvement, partnership and the development of social
capital. High and low road approaches are compared, in an evaluation of the Improving Working Lives programme.
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7.
Recent growth of the geospatial information on the web has made it possible to easily access a wide variety of spatial data.
The ability to combine various sets of geospatial data into a single composite dataset has been one of central issues of modern
geographic information processing. By conflating diverse spatial datasets, one can support a rich set of queries that could
have not been answered given any of these sets in isolation. However, automatically conflating geospatial data from different
data sources remains a challenging task. This is because geospatial data obtained from various data sources may have different
projections, different accuracy levels and different formats (e.g., raster or vector format), thus resulting in various positional
inconsistencies. Most of the existing algorithms only deal with vector to vector data conflation or require human intervention
to accomplish vector data to imagery conflation. In this paper, we describe a novel geospatial data fusion approach, named
AMS-Conflation, which achieves automatic vector to imagery conflation. We describe an efficient technique to automatically
generate control point pairs from the orthoimagery and vector data by exploiting the information from the vector data to perform
localized image processing on the orthoimagery. We also evaluate a filtering technique to automatically eliminate inaccurate
pairs from the generated control points. We show that these conflation techniques can automatically align the roads in orthoimagery,
such that 75% of the conflated roads are within 3.6 meters from the real road axes compared to 35% for the original vector
data for partial areas of the county of St. Louis, MO.
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8.
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
9.
Nowadays data mining plays an important role in decision making. Since many organizations do not possess the in-house expertise
of data mining, it is beneficial to outsource data mining tasks to external service providers. However, most organizations
hesitate to do so due to the concern of loss of business intelligence and customer privacy. In this paper, we present a Bloom
filter based solution to enable organizations to outsource their tasks of mining association rules, at the same time, protect
their business intelligence and customer privacy. Our approach can achieve high precision in data mining by trading-off the
storage requirement.
This research was supported by the USA National Science Foundation Grants CCR-0310974 and IIS-0546027.
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10.
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.
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11.
The complexity of group dynamics occurring in small group interactions often hinders the performance of teams. The availability
of rich multimodal information about what is going on during the meeting makes it possible to explore the possibility of providing
support to dysfunctional teams from facilitation to training sessions addressing both the individuals and the group as a whole.
A necessary step in this direction is that of capturing and understanding group dynamics. In this paper, we discuss a particular
scenario, in which meeting participants receive multimedia feedback on their relational behaviour, as a first step towards
increasing self-awareness. We describe the background and the motivation for a coding scheme for annotating meeting recordings
partially inspired by the Bales’ Interaction Process Analysis. This coding scheme was aimed at identifying suitable observable
behavioural sequences. The study is complemented with an experimental investigation on the acceptability of such a service.
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12.
We present a vision- and ladar-based approach to autonomous driving on rural and desert roads that has been tested extensively
in a closed-loop system. The vision component uses Gabor wavelet filters for texture analysis to find ruts and tracks from
which the road vanishing point can be inferred via Hough-style voting, yielding a direction estimate for steering control.
The ladar component projects detected obstacles along the road direction onto the plane of the front of the vehicle and tracks
the 1-D obstacle “gap” presumed due to the road to yield a lateral offset estimate. Several image- and state-based tests to
detect failure conditions such as off-road poses (i.e., there is no road to follow) and poor lighting due to sun glare or
distracting shadows are also explained. The system’s efficacy is demonstrated with analysis of diverse logged data including
from the 2005 DARPA Grand Challenge, as well as tests with full control of a vehicle over 15 km of difficult roads at up to
37 km/h with no waypoints.
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13.
Awareness systems have attracted significant research interest for their potential to support interpersonal relationships.
Investigations of awareness systems for the domestic environment have suggested that such systems can help individuals stay
in touch with dear friends or family and provide affective benefits to their users. Our research provides empirical evidence
to refine and substantiate such suggestions. We report our experience with designing and evaluating the ASTRA awareness system,
for connecting households and mobile family members. We introduce the concept of connectedness and its measurement through
the Affective Benefits and Costs of communication questionnaire (ABC-Q). We inform results that testify the benefits of sharing
experiences at the moment they happen without interrupting potential receivers. Finally, we document the role that lightweight,
picture-based communication can play in the range of communication media available.
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14.
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.
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15.
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.
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16.
A new design approach to create an efficient high-performance JPEG-LS encoder is proposed in this paper. The proposed implementation
compresses the image data with the lossless mode of JPEG-LS. When the acquisition of precious content (image) is specified
to occur in real-time, then lossless compression is essential. Lossless compression is important to critical applications,
such as the acquisition of medical images and transmission of high-definition high-resolution images from space (satellite).
The contribution of the paper is to introduce an efficient pipelined JPEG-LS encoder, which requires significantly lower encoding
time than any other available JPEG-LS hardware or software implementation. The experimental results show that encoding is
performed as expected in high-speed, being able to serve real-time applications. This is the first time that a JPEG-LS implementation
offers such a high-speed encoding.
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17.
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.
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18.
The Open Geospatial Consortium Web Processing Service specification is intended as a solution for creating and distributing
web-based functions. This paper seeks to evaluate the WPS specification with respect to feasibility and utility, to identify
areas for improvement, and to provide a demonstration implementation approach including a client-side tool and a server-side
wrapping technique for exposing geoprocessing functionality through WPS using an asynchronous approach. Challenges with the
WPS specification, some of which are already being addressed in the newest WPS revisions, are discussed together with proposed
solutions. Several potential enhancements to the WPS proposal are introduced and considered, including a mechanism to guide
client applications in prompting for correct data and a means to list the data available on a server.
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19.
We define a new birth and death dynamics dealing with configurations of disks in the plane. We prove the convergence of the
continuous process and propose a discrete scheme converging to the continuous case. This framework is developed to address
image processing problems consisting in detecting a configuration of objects from a digital image. The derived algorithm is
applied for tree crown extraction and bird detection from aerial images. The performance of this approach is shown on real
data.
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20.
Three dimensional human motions recorded by motion capture and hand gestures recorded by using data gloves generate variable-length
data streams. These data streams usually have dozens of attributes, and have different variations for similar motions. To
segment and recognize motion streams, a classification-based approach is proposed in this paper. Classification feature vectors
are extracted by utilizing singular value decompositions (SVD) of motion data. The extracted feature vectors capture the dominating
geometric structures of motion data as revealed by SVD. Multi-class support vector machine (SVM) classifiers with class probability
estimates are explored for classifying the feature vectors in order to segment and recognize motion streams. Experiments show
that the proposed approach can find patterns in motion data streams with high accuracy.
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