15576082
Real-time component-based systems
Component technology has become a central focus of software engineering in research and development. Reusability is a key factor that contributes to its success. The reuse of components can lead to a shortening of software development cycles and savings in software development costs. However, existing component models provide no support for real-time services and some real-time extensions of component models lack of consideration for reusability of components in providing real-time services. In this work, we develop a real-time component-based system that maintains the reusability of components.
6827646
Design and implementation of QoS-provisioning system for voice over IP
In this paper, we address issues in implementing voice over IP (VoIP) services in packet switching networks. VoIP has been identified as a critical real-time application in the network QoS research community and has been implemented in commercial products. To provide competent quality of service for VoIP systems comparable to traditional PSTN systems, a call admission control (CAC) mechanism has to be introduced to prevent packet loss and over-queuing. Several well-designed CAC mechanisms, such as the site-utilization-based CAC-and the link-utilization-based CAC mechanisms have been in place. However, the existing commercial VoIP systems have not been able to adequately apply and support these CAC mechanisms and, hence, have been unable to provide QoS guarantees to voice over IP networks. We have designed and implemented a QoS-provisioning system that can be seamlessly integrated with the existing VoIP systems to overcome their weakness in offering QoS guarantees. A practical implementation of our QoS-provisioning system has been realized.
8639082
Delay Analysis in Temperature-Constrained Hard Real-Time Systems with General Task Arrivals
In this paper, we study temperature-constrained hard real-time systems, where real-time guarantees must be met without exceeding safe temperature levels within the processor. Dynamic speed scaling is one of the major techniques to manage power so as to maintain safe temperature levels. As example, we adopt a simple reactive speed control technique in our work. We design a methodology to perform delay analysis for general task arrivals under reactive speed control with first-in-first-out (FIFO) scheduling and static-priority (SP) scheduling. As a special case, we obtain a close-form delay formula for the leaky-bucket task arrival model. Our data show how simple reactive speed control can decrease the delay of tasks compared with any constant-speed scheme
5741503
A new scheme on privacy-preserving data classification
We address privacy-preserving classification problem in a distributed system. Randomization has been the approach proposed to preserve privacy in such scenario. However, this approach is now proven to be insecure as it has been discovered that some privacy intrusion techniques can be used to reconstruct private information from the randomized data tuples. We introduce an algebraic-technique-based scheme. Compared to the randomization approach, our new scheme can build classifiers more accurately but disclose less private information. Furthermore, our new scheme can be readily integrated as a middleware with existing systems.
15389203
Analyzing and enhancing the resilience of structured peer-to-peer systems
In this paper, we propose an approach to analyze the resilience of structured peer-to-peer (P2P) systems under failures. The approach is Markov-chain based, and can be applied to systems with relatively stable size and uniform distribution of nodes. We apply our approach to several well-known structured P2P systems. We find that different system features (types of neighbors of nodes) in P2P systems have different impacts on their resilience against failures. Following this observation, we propose to add some extra neighbor(s) to CAN using small-world model principles to form a so-called CAN-SW system. We then apply the proposed approach to analyze its resilience. We find that the performance is improved significantly, particularly, in terms of the average path length.
35567316
Computational Analysis of Gene Identification with SAGE
SAGE is one of the few techniques capable of uniformly probing gene expression at a genome level irrespective of mRNA abundance and without a priori knowledge of the transcripts present. However, individual SAGE tags can match many sequences in the reference database, complicating gene identification. We perform a baseline evaluation of gene identification with SAGE using UniGene Human as the reference database by analyzing 1) the distributions of tags for various length tag sets formed for UniGene Human and 2) the tag-to-sequence mapping using a SAGE tag set consisting of 37,522 tags derived from human myeloid cells. The extensive multiplicity of the dbEST component of UniGene significantly detracts from gains that might be expected by extending tags within the scope of the SAGE protocol. In order to achieve reasonable sequence specificity for gene identification with the content of the commonly used UniGene sequence collection, tags on the order of hundreds of bases in length are required. One way to produce tags of such lengths is with GLGI, which extends SAGE tags to the 3' end of cDNA. We show that the longer sequences produced by GLGI relieve significantly the multiple match condition. In the myeloid sample, we also found a correlation between multiple match severity and high copy number. We extrapolate these findings, providing insights into the use of UniGene Human as a reference for gene identification.
11079160
An Anonymous Endorsement System
The expression of one’s opinion through endorsement is one of the simplest methods of democratic participation. The result of an endorsement can be used to evaluate whether a certain subject should deserve a higher attention. In some cases, the endorsers desire privacy protection. However, conventional paper-based endorsement systems provide neither convenience nor well privacy protection for the endorsers. In addition, current electronic anonymous voting schemes are unsuitable for anonymous endorsement. This motivates us to develop an anonymous endorsement system that can be realized on computer networks. The proposed system satisfies completeness, soundness, privacy, unreusability, eligibility, and verifiability. In practice, the proposed system can be integrated with the conventional paper-based endorsement system.
15418757
Fingerprint classification by directional fields
Fingerprint classification provides an important fingerprint index and can reduce fingerprint matching time in a large database. A good classification algorithm can give an accurate index that is able to search a fingerprint database more effectively. We present a fingerprint classification algorithm that is based on directional fields. We compute directional fields of fingerprint images and detect singular points (cores). Then, we extract features that we define from fingerprint images. We also use k-means classifier and 3-nearest neighbor to classify features and distinguish which fingerprint is Arch, Left Loop, Right Loop, or Whorl. Experimental results show a significant improvement in fingerprint classification performance. Moreover, the time required for the classification algorithm is reduced.
11278363
A Distributed Artificial Network Solving Complex and Multiple Causal Associations
Causal reasoning (known also as abduction) is a hard task that cognitive agents perform reliably and quickly. A particular class of causal reasoning that raises several difficulties is the cancellation class. Cancellation occurs when a set of causes (hypotheses) cancel each other's explanation with respect to a given effect (observation). For example, a cloudy sky may suggest a rainy weather; whereas a shiny sky may suggest the absence of rain. In the current paper, we extend a recent neural model to handle cancellation interactions. We conduct a sensitivity analysis of this proposal on ad hoc problems put at extreme cases. Finally, we test the model on a large database and propose objective criteria to quantitatively evaluate its performance. Simulation results are very satisfactory and should encourage research.
33546649
Distinguishing between overlapping components in mixture models