There is a growing interest in the use of ontologies for multi-agent system app- cations. On the one hand, the agent paradigm is successfully employed in those applications where autonomous, loosely-coupled, heterogen...
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ISBN:
(数字)9783764373610
ISBN:
(纸本)9783764372378
There is a growing interest in the use of ontologies for multi-agent system app- cations. On the one hand, the agent paradigm is successfully employed in those applications where autonomous, loosely-coupled, heterogeneous, and distributed systems need to interoperate in order to achieve a common goal. On the other hand, ontologies have established themselves as a powerful tool to enable kno- edge sharing, and a growing number of applications have bene?ted from the use of ontologies as a means to achieve semantic interoperability among heterogeneous, distributed systems. In principle ontologies and agents are a match made in heaven, that has failed to happen. What makes a simple piece of software an agent is its ability to communicate in a ”social” environment, to make autonomous decisions, and to be proactive on behalf of its user. Communication ultimately depends on und- standing the goals, preferences, and constraints posed by the user. Autonomy is theabilitytoperformataskwithlittleornouserintervention,whileproactiveness involves acting autonomously with no need for user prompting. Communication, but also autonomy and proactiveness, depend on knowledge. The ability to c- municate depends on understanding the syntax (terms and structure) and the semantics of a language. Ontologies provide the terms used to describe a domain and the semantics associated with them. In addition, ontologies are often comp- mented by some logical rules that constrain the meaning assigned to the terms. These constraints are represented by inference rules that can be used by agents to perform the reasoning on which autonomy and proactiveness are based.
There is an increasing interest in techniques that support measurement and analysis of fielded software systems. One of the main goals of these techniques is to better understand how software actually behaves in the f...
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ISBN:
(纸本)1595930140
There is an increasing interest in techniques that support measurement and analysis of fielded software systems. One of the main goals of these techniques is to better understand how software actually behaves in the field. In particular, many of these techniques require a way to distinguish, in the field, failing from passing executions. So far, researchers and practitioners have only partially addressed this problem: they have simply assumed that program failure status is either obvious (i.e., the program crashes) or provided by an external source (e.g., the users). In this paper, we propose a technique for automatically classifying execution data, collected in the field, as coming from either passing or failing program runs. (Failing program runs are executions that terminate with a failure, such as a wrong outcome.) We use statistical learning algorithms to build the classification models. Our approach builds the models by analyzing executions performed in a controlled environment (e.g., test cases run in-house) and then uses the models to predict whether execution data produced by a fielded inst.nce were generated by a passing or failing program execution. We also present results from an initial feasibility study, based on multiple versions of a software subject, in which we investigate several issues vital to the applicability of the technique. Finally, we present some lessons learned regarding the interplay between the reliability of classification models and the amount and type of data collected. Copyright 2005 ACM.
In this paper, we propose a multi-rate CSMA/CA-based MAC protocol, which we refer to as EMR, to enable fast forwarding of frames in a more efficient manner. We use the base-rate RTS and CTS frames to reserve a long tr...
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In this paper, we propose a multi-rate CSMA/CA-based MAC protocol, which we refer to as EMR, to enable fast forwarding of frames in a more efficient manner. We use the base-rate RTS and CTS frames to reserve a long transmission path and utilize intermediate nodes to relay the data frames using shorter transmission distance but with more efficient transmission rates. Results show that our EMR scheme can outperform the traditional multi-rate forwarding scheme by 18% and 49.4% in a low-density and high-density ad hoc network, respectively.
The VoIP is a newest killer application nowadays on Internet which is expected to be carried on at anytime and anywhere. However, the re-configuration problem as well as signaling and transmission delay will be major ...
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The VoIP is a newest killer application nowadays on Internet which is expected to be carried on at anytime and anywhere. However, the re-configuration problem as well as signaling and transmission delay will be major concerns for a mobile node moving into a foreign network. In this paper, we design the pseudo SIP server under a configuration-free Ad-Hoc architecture VoIP system. The innovation of proposed pseudo SIP server solves the problem with no standalone SIP server on Ad-Hoc network. The performance evaluation of the proposed pseudo SIP server also shows significant improvement in SIP signaling delay.
This paper presents a system for automatic news video indexing, browsing and retrieval. The system employs visual clues to effectively parse the news video into story units, to generate visual-table-of-contents and in...
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This paper presents a system for automatic news video indexing, browsing and retrieval. The system employs visual clues to effectively parse the news video into story units, to generate visual-table-of-contents and indexes for supporting browsing and retrieval. The efficiency of the system has been tested on several video sequences.
The paper gives an overview of the Yoto project, a novel e-learning initiative to build up an electrical engineering knowledge base. It also presents a new e-module of the project relating to the steady-state operatio...
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ISBN:
(纸本)9075815085
The paper gives an overview of the Yoto project, a novel e-learning initiative to build up an electrical engineering knowledge base. It also presents a new e-module of the project relating to the steady-state operation of dc-dc converters. The multimedia rich module contains numerous interactive tools promoting the high level education in the academy sector and the vocational trainings in the industry. The interactive tools also highly support the circuit design process by enabling fast calculation and access to relevant circuit quantities and waveforms (voltages and currents) in steady-state without long simulations.
Sensor networks consist of small wireless sensor nodes deployed randomly over an area to monitor the environment or detect intrusion. The coverage provided by sensor networks is very crucial to their effectiveness. Ma...
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Sensor networks consist of small wireless sensor nodes deployed randomly over an area to monitor the environment or detect intrusion. The coverage provided by sensor networks is very crucial to their effectiveness. Many of the important applications of sensor networks demand autonomous mobility for the sensor nodes. Early failure of sensor nodes can lead to coverage loss that requires coverage maintenance schemes. In this paper, we propose dynamic coverage maintenance (DCM) schemes that exploit the limited mobility of the sensor nodes. The main objective of coverage maintenance is to compensate the loss of coverage with minimum expenditure of energy. We propose a set of DCM schemes which can be executed on individual sensor nodes having a knowledge of only their local neighborhood topology. We propose four algorithms to decide which neighbors to migrate, and to what distance, such that the energy expended is minimized and the coverage obtained for a given number of live nodes is maximized. The decision and movement is completely autonomous in the network, and involves movement of one-hop neighbors of a dead sensor node. We also propose an extension to these algorithms, called cascaded DCM, which extends the migrations to multiple hops. We have also compared the performance of the different algorithms in terms of the improvement in coverage, average migration distance of the nodes, and the lifetime of the network
The negative bias temperature inst.bility (NBTI) of p-MOSFETs is an important reliability issue for digital as well as analog CMOS circuits. To date, characterization and modeling efforts to analyze the NBTI mechanism...
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The negative bias temperature inst.bility (NBTI) of p-MOSFETs is an important reliability issue for digital as well as analog CMOS circuits. To date, characterization and modeling efforts to analyze the NBTI mechanism involve devices stressed with zero substrate bias (VB). However, many circuits utilize nonzero V/sub B/ to vary the device threshold voltage (V/sub T/), (e.g., for dual V/sub T/ CMOS, standby leakage reduction, etc.). This paper aims to systematically study NBTI for V/sub B/>0 V stress, which, to the best of our knowledge, has not been done so far. It is shown that NBTI increases for V/sub B/>0 V stress. This is attributed to enhanced interface (N/sub IT/) and bulk (N/sub OT/) trap generation due to impact ionization and hot-hole (HH) generation. The role of gate bias (V/sub G/), V/sub B/, temperature (T) and oxide thickness (T/sub PHY/) is studied. This work would help all efforts in determining: (i) reliability budget for any operating V/sub B/; (ii) proper choice of stress V/sub B/ during accelerated aging tests; and (iii) suitable TCAD and SPICE models.
A numerical model has been developed to analyze and optimize the run-time performance of a disk drive spindle motor. A field-circuit coupled time-stepping finite element method is used for the analysis of the motor op...
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In this paper, we present an encryption scheme for MPEG-4 FGS which provides the same or a little coarser granularity of scalability after encryption. The scheme encrypts compressed data of each video packet or block ...
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In this paper, we present an encryption scheme for MPEG-4 FGS which provides the same or a little coarser granularity of scalability after encryption. The scheme encrypts compressed data of each video packet or block independently. Initialization vectors are generated with a method to minimize the overhead. The scalability provided in an encrypted codestream using this scheme enables intermediate nodes to truncate an encrypted bitstream at near R-D optimality directly without decryption, which enhances system security. The scheme has virtually negligible overhead, and produces encrypted codestream with virtually the same error resilience performance as the unencrypted case. These features are very desirable in many applications
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