This research provides security and safety extensions to a blockchain based solution whose target is e-health. The Advanced Blockchain platform is extended with intelligent monitoring for security and machine learning for detecting patient treatment medication safety issues. For the reasons of stringent HIPAA, HITECH, EU-GDPR and other regional regulations dictating security, safety and privacy requirements, the e-Health blockchains have to cover mandatory disclosure of violations or enforcements of policies during transaction flows involving healthcare. Our service solution further provides the benefits of resolving the abnormal flows of a medical treatment process, providing accountability of the service providers, enabling a trust health information environment for institutions to handle medication safely, giving patients a better safety guarantee, and enabling the authorities to supervise the security and safety of e-Health blockchains. The capabilities can be generalized to support a uniform smart solution across industry in a variety of blockchain applications.

This paper presents our edge device centric architecture as a new system solution for internet e-Health objects interconnection and service delivery. The new approach was designed to enable new embedded health objects, to meet the growth in edge devices, to provide secure operations, as well as to establish a new e-Health interactive norms. It is going to enable the Internet of Things in the e-Health industry with diverse edge devices and embedded managed objects being integrated at the core interconnection.

As the e-Health world is geared up for a more efficient rollout of fast healthcare resources, we designed our new Rapid Delivery e-Health Service (RDeHS) platform, which not only streamlines standard conformance through emerging technologies in e-Health resources. This paper reports the evolution in our new architectural approach for the purpose of rapid development and deployment of e-Health services to reduce healthcare costs and enhance quality of care.

This HealthCom short paper reports our new lab approach in the Smart and Connected e-Health Services (SCeHS). It summarizes the architecture and platform plan, the functional resources, and the application flows enablement SDN, connected via data virtualization and exchange protocols, for the purpose of e-Health service development and deployment.

Microbial interactions play important roles on the structure and function of complex microbial communities. With the rapid accumulation of high-throughput metagenomic or 16S rRNA sequencing data, it is possible to infer complex microbial interactions. Co-occurrence patterns of microbial species among multiple samples are often utilized to infer interactions. There are few methods to consider the temporally interacting patterns among microbial species. In this paper, we present a Graph-regularized Vector Autoregressive (GVAR) model to infer causal relationships among microbial entities. The new model has advantage comparing to the original vector autoregressive (VAR) model. Specifically, GVAR can incorporate similarity information for microbial interaction inference--i.e., GVAR assumed that if two species are similar in the previous stage, they tend to have similar influence on the other species in the next stage. We apply the model on a time series dataset of human gut microbiome which was treated with repeated antibiotics. The experimental results indicate that the new approach has better performance than several other VAR-based models and demonstrate its capability of extracting relevant microbial interactions.

As various e-Health providers gain access to new sources of electronic health data while more entities are collecting evidence of effective healthcare procedures, we research the privacy/security/trust services mechanisms in the expanding electronic healthcare and administration environment to enable mobile e-Health applications deployment. To address the significant trends in e-Health PST rules after Stages 1/2/3 implementations, we have worked on the computational, networking and operational issues that arise from mobile e-Health PST. Our research provides a much needed innovative infrastructure framework to address the new e-Health challenges and requirements as presented in this paper.

As the world is gearing up towards implementation of digital healthcare networking solutions, the solution roadmap for a national e-Health interconnection network infrastructure is in great demand. This paper first identifies the major benefits in interconnection services that are critical to universal deployment. Then it provides an overview of our e-Health AON (Application Oriented Network) approach that offers direct support to the aspects of interconnection services, operational management services, and security control services. To further achieve the desired effects, this paper presents performance validation plans to assist the realization of a universal e-Health application interconnection network.

Detection and identification of seismic P-Wave is useful in event location and event detection. This involves an intensive amount of pattern recognition. For the recognition of seismic phases, no probabilistic distribution model performs as well as Artificial Neural Network(ANN). Back Propagation Neural Network (BPNN) was applied for the automatic detection and identification of local and regional seismic P-Waves. For a set of three-component seismic data, four attributes were used as input to the ANN: Degree of Polarization (DOP), Auto Regression Coefficient (ARC), Ratio between Short time average and Long time average (STA/LTA) and Ratio of Vertical power to Total power (RV2T). These four attributes were calculated in the frequency band of 1–8 Hz with a 2 second moving window. The results of preliminary training and testing with a set of various local and regional earthquake recordings show that the ANN achieved 95% correct rate of P-Wave detection and identification. 90% of the P-Waves were detected with a maximum deviation of 0.1 sec from correct manual pick up.

In this paper, we deal with two research issues: the automation of visual attribute identification and semantic relation learning between visual attributes and object categories. The contribution is two-fold, firstly, we provide uniform framework to reliably extract both categorical attributes and depictive attributes. Secondly, we incorporate the obtained semantic associations between visual attributes and object categories into a text-based topic model and extract descriptive latent topics from external textual knowledge sources. Specifically, we show that in mining natural language descriptions from external knowledge sources, the relation between semantic visual attributes and object categories can be encoded as Must-Links and Cannot-Links, which can be represented by Dirichlet-Forest prior. To alleviate the workload of manual supervision and labeling in image categorization process, we introduce a semi-supervised training framework using soft-margin semi-supervised SVM classifier. We also show that the large-scale image categorization results can be significantly improved by combining automatically acquired visual attributes. Experimental results show that the proposed model achieves better ability in describing object-related attributes and makes the inferred latent topics more descriptive.

The research efforts for a national eHealth interconnection infrastructure and design guidelines are in great demand. This paper identifies the major challenges in eHealth interconnection network services that are critical to universal deployment. An overview of our solutions framework is summarized with the aspects of interconnection services, operational management services, and security control services.

We examine e-Healthcare security challenges in order to address the emerging needs of a national digital healthcare solution. New security concerns arise in transmitting and processing of electronic medical records, personal healthcare records, patient billing records, as well as public health alerts, across many parties with varying security, privacy and trust levels. Additional security requirements in e-Healthcare settings have to be formulated beyond traditional data networking services. Our results include an e-Healthcare security solution framework that enables multi-party participation, allows variable visibility into selective parts of data, and guarantees end-to-end security control.

In this paper, we present a method that enable both homology-based approach and composition-based approach to further study the functional core (i.e., microbial core and gene core, correspondingly). In the proposed method, the identification of major functionality groups is achieved by generative topic modeling, which is able to extract useful information from unlabeled data. We first show that generative topic model can be used to model the taxon abundance information obtained by homology-based approach and study the microbial core. The model considers each sample as a “document,” which has a mixture of functional groups, while each functional group (also known as a “latent topic”) is a weight mixture of species. Therefore, estimating the generative topic model for taxon abundance data will uncover the distribution over latent functions (latent topic) in each sample. Second, we show that, generative topic model can also be used to study the genome-level composition of “N-mer” features (DNA subreads obtained by composition-based approaches). The model consider each genome as a mixture of latten genetic patterns (latent topics), while each functional pattern is a weighted mixture of the “N-mer” features, thus the existence of core genomes can be indicated by a set of common N-mer features. After studying the mutual information between latent topics and gene regions, we provide an explanation of the functional roles of uncovered latten genetic patterns. The experimental results demonstrate the effectiveness of proposed method.

With the fast growing number of works utilizing link information in enhancing unsupervised document clustering, it is becoming necessary to make a comparative evaluation of the impacts of different link types on document clustering. Various types of links between text documents, including explicit links such as citation links and hyperlinks, implicit links such as coauthorship and cocitation links, and similarity links such as content similarity links, convey topic similarity or topic transferring patterns, which is very useful for document clustering. In this paper, we adopt a clustering algorithm based on Markov random field and relaxation labeling, which employs both content and linkage information, to evaluate the effectiveness of the aforementioned types of links for document clustering on ten data sets. The experimental results show that linkage information is quite effective in improving content-based document clustering. Furthermore, a series of important findings regarding the impacts of different link types on document clustering is discovered through our experiments.

In this paper, we proposed a perspective Hierarchical Dirichlet Process (pHDP) model to deal with user-tagged image modeling. The contribution is two-fold. Firstly, we associate image features with image tags. Secondly, we incorporate the user's perspectives into the image tag generation process and introduce new latent variables to determine if an image tag is generated from user's perspectives or from the image content. Therefore, the model is able to extract both embedded semantic components and user's perspectives from user-tagged images. Based on the proposed pHDP model, we achieve automatic image tagging with users' perspective. Experimental results show that the pHDP model achieves better image tagging performance compared to state-of-the-art topic models.

The research effort for a national e-Health interconnection infrastructure and for the needs of supporting design guidelines is in great demand. This paper presents our approach towards an e-Health processing QoS framework for network infrastructure management in order to design and implement e-Health communication quality of service guarantees.

A key goal of the Semantic Web is to shift social interaction patterns from a producer-centric paradigm to a consumer-centric one. Treating customers as the most valuable assets and making the business models work better for them are at the core of building successful consumer-centric business models. It follows that customizing business processes constitutes a major concern in the realm of a knowledge-pull-based human semantic Web. This paper conceptualizes the customization of service-based business processes leveraging the existing knowledge of Web services and business processes. We represent this conceptualization as a new Extensible Markup Language (XML) markup language Web Ontology Language-Business Process Customization (OWL-BPC), based on the de facto semantic markup language for Web-based information [Web Ontology Language (OWL)]. Furthermore, we report a framework, built on OWL-BPC, for customizing service-based business processes, which supports customization detection and enactment. Customization detection is enabled by a business-goal analysis, and customization enactment is enabled via event-condition-action rule inference. Our solution and framework have the following capabilities in dealing with inconsistencies and misalignments in business process interactions: 1) resolve semantic mismatch of process parameters; 2) handle behavioral mismatches which may or may not be compatible; and 3) process misaligned rendezvous requirements. Such capabilities are applicable to business processes with heterogeneous domain ontology. We present an architectural description of the implementation and a walk-through of an example of solving a customization problem as a validation of the proposed approach.

Abstract In this paper, we study the problem of distributed virtual backbone construction in sensor networks, where the coverage area of nodes are disks with different radii. This problem is modeled by the construction of a minimum connected dominating set (MCDS) in geometric k‐disk graphs. We derive the size relationship of any maximal independent set (MIS) and MCDS in geometric k‐disk graphs, and apply it to analyze the performances of two distributed connected dominating set (CDS) algorithms we propose in this paper. These algorithms have bounded performance ratio and low communication overhead. To the best of our knowledge, the results reported in this paper represent the state‐of‐the‐art. Copyright © 2009 John Wiley & Sons, Ltd.

The explosive increase of image data on Internet has made it an important, yet very challenging task to index and automatically annotate image data. To achieve that end, sophisticated algorithms and models have been proposed to study the correlation between image content and corresponding text description. Despite the success of previous works, however, researchers are still facing two major difficulties that may undermine their effort of providing reliable and accurate annotations for images. The first difficulty is lacking of comprehensive benchmark image dataset with high quality text descriptions. The second difficulty is lacking of effective way to represent the image content and make it associate with the text descriptions. In our paper, we aim to deal with both problems. To deal with the first problem, we utilize Wikipedia as external knowledge source and enrich the ontology structure of ImageNet database with comprehensive and highly-reliable text descriptions from Wikipedia articles. To address the second problem, we develop a Probabilistic Topic-Connection (PTC) model to represent the connection between latent semantic topic in text description and latent patterns from image feature space. We compare the performance of our model with the currently popular Correspondence LDA (Corr-LDA) model under the same automatic image annotation scenario using cross-validation. Experimental results demonstrate that our model is able to well represent the connection between latent semantic topics and latent patterns in image feature space, thus facilitates knowledge organization and understanding of both image and text descriptions.

From the pervasive application standpoint, healthcare IT (HIT) infrastructure and applications have become enablers to revolutionize the roles and responsibility of the healthcare professionals as well as consumers. This paper describes our research in next generation service creation systems that support pervasive healthcare applications together with additional operational management capabilities. We present a platform level solution for rapid communication session service creation by incorporating existing and new healthcare information network and operational capabilities. We also uncover and re-exam some complexity currently overlooked in large-scale trials at the national level.

This paper presents a communication framework for end-to-end seamless connections and TCP performance improvement in the IEEE802.il wireless home network platform exploiting dual wireless modes, infrastructure and ad hoc modes. While many ad hoc routing protocols for end-to-end seamless connections and cross-layer techniques available in the literature have been proposed at the level of protocol design and simulations, the availability of ad hoc routing protocol implementation is far from satisfying. The proposed communication framework is implemented as a virtual network device driver on the Linux operating system and evaluated to verify its application and efficiency. Practical experiments showed that the proposed communication framework yielded efficient performance in terms of low packet transmission failure rate, fast packet transmission time, and high TCP performance.

Assessing network vulnerability before potential disruptive events such as natural disasters or malicious attacks is vital for network planning and risk management. It enables us to seek and safeguard against most destructive scenarios in which the overall network connectivity falls dramatically. Existing vulnerability assessments mainly focus on investigating the inhomogeneous properties of graph elements, node degree for example, however, these measures and the corresponding heuristic solutions can provide neither an accurate evaluation over general network topologies, nor performance guarantees to large scale networks. To this end, in this paper, we investigate a measure called pairwise connectivity and formulate this vulnerability assessment problem as a new graph-theoretical optimization problem called ß-disruptor, which aims to discover the set of critical node/edges, whose removal results in the maximum decline of the global pairwise connectivity. Our results consist of the NP-Completeness and inapproximability proof of this problem, an O(log n log log n) pseudo-approximation algorithm for detecting the set of critical nodes and an O(log1.5n) pseudo-approximation algorithm for detecting the set of critical edges. In addition, we devise an efficient heuristic algorithm and validate the performance of the our model and algorithms through extensive simulations.

BACKGROUND: Protein translation is a vital cellular process for any living organism. The availability of interaction databases provides an opportunity for researchers to exploit the immense amount of data in silico such as studying biological networks. There has been an extensive effort using computational methods in deciphering the transcriptional regulatory networks. However, research on translation regulatory networks has caught little attention in the bioinformatics and computational biology community. RESULTS: In this paper, we present an exploratory analysis of yeast protein translation regulatory networks using hierarchical random graphs. We derive a protein translation regulatory network from a protein-protein interaction dataset. Using a hierarchical random graph model, we show that the network exhibits well organized hierarchical structure. In addition, we apply this technique to predict missing links in the network. CONCLUSIONS: The hierarchical random graph mode can be a potentially useful technique for inferring hierarchical structure from network data and predicting missing links in partly known networks. The results from the reconstructed protein translation regulatory networks have potential implications for better understanding mechanisms of translational control from a system's perspective.

In this paper we present throughput analysis for a contention-based dynamic spectrum sharing model. We consider two scenarios of allocating channels to primary users, fixed allocation and random allocation. In fixed allocation, the number of primary users allocated to a channel is fixed all the time, but the number of users in different channels may be different. In random allocation, each primary user dynamically and randomly selects a channel in each time slot. We assume that the spectrum band of primary users is divided into multiple channels and the time is slotted. Primary users allocated to a specific channel compete to access this channel in each time slot. Secondary users are able to dynamically detect the idle channels in each time slot, and compete to access these channels. We develop analytical models for the throughput of primary users and secondary users in both scenarios and examine the impact of the number of secondary users on the throughput of the system. For a given number of primary users, channels and traffic generation probability, we aim to find the number of secondary users to maximize the total throughput of both primary users and secondary users. Our solutions match closely with the numerical results.

In this poster, we investigate how to enhance web clustering by leveraging the tripartite network of social tagging systems. We propose a clustering method, called "Tripartite Clustering", which cluster the three types of nodes (resources, users and tags) simultaneously based on the links in the social tagging network. The proposed method is experimented on a real-world social tagging dataset sampled from del.icio.us. We also compare the proposed clustering approach with K-means. All the clustering results are evaluated against a human-maintained web directory. The experimental results show that Tripartite Clustering significantly outperforms the content-based K-means approach and achieves performance close to that of social annotation-based K-means whereas generating much more useful information.

Achieving efficient bandwidth utilization in multi-channel sensor networks is a challenging research problem. In this paper, we present a cognitive load balance algorithm for single-hop multi-channel sensor networks. Based on the load distribution of all base stations, our algorithm dynamically alternates the communication channels. As a result, the extra load from over-loaded channels is directed to under-loaded channels with a computed switch probability. In this paper, we also prove that a high throughput can be achieved if the load is balanced. The performance of the load balance algorithm is evaluated through both theoretical analysis and simulation study.

In this paper, we propose a novel hardware-software codesign technique of network protocol stacks on a SoC (system on chip) platform for providing the QoS (quality of service) functionality. We address that the codesign should guarantee the real-time performance of periodic packets and minimize the average response time of aperiodic packets in order to provide the QoS functionality. We present the following three mechanisms to resolve this issue: 1) task decomposition technique of a network protocol suite into hardware and software tasks, 2) a communication channel between heterogeneous tasks, 3) fine-grained and coarse-grained real-time processing simultaneously for application-specific real-time requirements. A case study based on experiments is conducted to illustrate the efficiency of the proposed technique by implementing it on the commercial SoC platform embedded with the Altera's Excalibur EPXA4 including ARM922T core and 400K gates of programmable logic.

Opportunistic spectrum access presents a new approach to wireless spectrum utilization and management. In this paper, we propose a non-cooperative based OSA approach: learning-based approach to allow multiple secondary users to achieve maximal throughput in an unslotted opportunistic spectrum access (OSA) network. In this approach, collisions among secondary users are taken into consideration while making channel sensing decisions. Spectrum maps for secondary users are estimated based on occurrence of collisions. Our approach allows secondary users to achieve maximal throughput by seeking independent spectrum opportunities without exchanging any control information among secondary users. Numerical results show that the learning-based approach obtains near-optimal performance in most of the scenarios.

In traditional text clustering methods, documents are represented as "bags of words" without considering the semantic information of each document. For instance, if two documents use different collections of core words to represent the same topic, they may be falsely assigned to different clusters due to the lack of shared core words, although the core words they use are probably synonyms or semantically associated in other forms. The most common way to solve this problem is to enrich document representation with the background knowledge in an ontology. There are two major issues for this approach: (1) the coverage of the ontology is limited, even for WordNet or Mesh, (2) using ontology terms as replacement or additional features may cause information loss, or introduce noise. In this paper, we present a novel text clustering method to address these two issues by enriching document representation with Wikipedia concept and category information. We develop two approaches, exact match and relatedness-match, to map text documents to Wikipedia concepts, and further to Wikipedia categories. Then the text documents are clustered based on a similarity metric which combines document content information, concept information as well as category information. The experimental results using the proposed clustering framework on three datasets (20-newsgroup, TDT2, and LA Times) show that clustering performance improves significantly by enriching document representation with Wikipedia concepts and categories.

Generating high-quality gene clusters and identifying the underlying biological mechanism of the gene clusters are the important goals of clustering gene expression analysis. To get high-quality cluster results, most of the current approaches rely on choosing the best cluster algorithm, in which the design biases and assumptions meet the underlying distribution of the dataset. There are two issues for this approach: 1) usually, the underlying data distribution of the gene expression datasets is unknown and 2) there are so many clustering algorithms available and it is very challenging to choose the proper one. To provide a textual summary of the gene clusters, the most explored approach is the extractive approach that essentially builds upon techniques borrowed from the information retrieval, in which the objective is to provide terms to be used for query expansion, and not to act as a stand-alone summary for the entire document sets. Another drawback is that the clustering quality and cluster interpretation are treated as two isolated research problems and are studied separately. In this paper, we design and develop a unified system Gene Expression Miner to address these challenging issues in a principled and general manner by integrating cluster ensemble, text clustering, and multidocument summarization and provide an environment for comprehensive gene expression data analysis. We present a novel cluster ensemble approach to generate high-quality gene cluster. In our text summarization module, given a gene cluster, our expectation-maximization based algorithm can automatically identify subtopics and extract most probable terms for each topic. Then, the extracted top k topical terms from each subtopic are combined to form the biological explanation of each gene cluster. Experimental results demonstrate that our system can obtain high-quality clusters and provide informative key terms for the gene clusters.

A holistic approach should be made for a wider adoption of a cross-layer approach. A cross-layer design on a wireless network assumed with a certain network condition, for instance, can have a limited usage in heterogeneous environments with diverse access network technologies and time varying network performance. The first step toward a cross-layer approach is an automatic detection of the underlying access network type, so that appropriate schemes can be applied without manual configurations. To address the issue, we investigate the characteristics of round-trip time (RTT) on wireless and wired networks. We conduct extensive experiments from diverse network environments and perform quantitative analyses on RTT variability. We show that RTT variability on a wireless network exhibits greatly larger mean, standard deviation, and min-to-high percentiles at least 10 ms bigger than those of wired networks due to the MAC layer retransmissions. We also find that the impact of packet size on wireless channel is particularly significant. Thus through a simple set of testing, one can accurately classify whether or not there has been a wireless network involved. We then propose effective adaptive cross-layer schemes for multimedia delivery over error-prone links. They include limiting the MAC layer retransmissions, controlling the application layer forward error correction (FEC) level, and selecting an optimal packet size. We conduct an analysis on the interplay of those adaptive parameters given a network condition. It enables us to find optimal cross-layer adaptive parameters when they are used concurrently.

This paper presents a framework of wireless multi-hop networks exploiting an ad hoc routing protocol working on the layer 2.5, called REAL (reputation based approach on 2.5-Layer) routing protocol. The framework of REAL routing protocol incorporates following three things: a new concept of wireless multi-hop network architecture, a new 2.5-layer routing technique with a reputation management scheme, and high throughput network performance based on cross-layer approaches between MAC (medium access control) and REAL layers. We compare the performance of the REAL routing protocol with previous routing algorithms, DSR (dynamic source routing) and AODV (ad hoc on demand distance vector). A case study on practical experiments and simulations shows that the REAL routing protocol yields better performance in terms of low rate of packet loss, fast packet delivery time, and high throughput network performance.

High bandwidth one-to-many applications emerging in IP over WDM optical networks demand multicast support at WDM layer so that data signals would be efficiently duplicated inside network without O/E/O conversion. Multicast trees in an optical layer can be built with light-trees which use light-splitting technique. Most of recent studies have been focused to efficiently build and configure light-trees without existing unicast or multicast traffic into consideration. In this paper we consider the dynamic and optimal design problem of multicast configuration for realistic and constrained WDM networks. In such a network, both unicast and multicast are supported, and WDM switches have limited number of wavelengths and light splitting capability. On the other hand, the amount of bandwidth per wavelength is abundant. Using subwavelength sharing among traffic demands of unicast and multicast, we build a hybrid virtual topology which exploits both existing light-trees and light- paths. By optimizing WDM resources in addition to resource sharing with existing unicast and multicast demands, we truly maximize the WDM layer capability and efficiently support more multicast traffic demands. We validate the efficiency of our approach with extensive simulations.

In this paper, we study the problem of minimum connected dominating set in geometric k-disk graphs. This research is motivated by the problem of virtual backbone construction in wireless ad hoc and sensor networks, where the coverage area of nodes are disks with different radii. We derive the size relationship of any maximal independent set and the minimum connected dominating set in geometric k-disk graphs, and apply it to analyze the performances of two distributed connected dominating set algorithms we propose in this paper. These algorithms have a bounded performance ratio and low communication overhead, and therefore have the potential to be applied in real ad hoc and sensor networks.

A vast number of broadcasting protocols have been developed for wireless networks. To the best of our knowledge, however, most of these protocols assume a single-radio single channel network model and/or a generalized physical model, which does not take into account the impact of interference. In this paper, we present a Distributed Interference-aware Broadcasting (DIB) protocol for multi-radio multi-channel mesh networks. The protocol has two phases. In the first phase, each node constructs a local structure by removing bad links and channels. In the second phase, a high-performance broadcasting tree is built by using message passing procedures. Our research distinguishes itself in a number of ways. First, a multi-radio multi-channel mesh network model is used. Second, comprehensive link and channel quality metrics are defined to fully take into account interferences. Third, four design principles have been identified in the tree building process to combat inter-node and intra-node interferences. Finally, a comprehensive performance metric, called power, is defined which includes reliability, receiving redundancy, latency, and goodput. Analytical and simulation studies verify that the DIB protocol is able to achieve 100% reliability, less broadcasting redundancy, low broadcasting latency, and high goodput.

In this paper, we present a novel technique that makes it possible to guarantee the real-time scheduling of periodic tasks and minimize the average response time of aperiodic tasks through a task decomposition technique for low-end WSN system platforms. This paper considers the following two perspectives. First, WSN platforms available in literature have not addressed the concept of scheduling for hybrid task sets where both types of periodic and aperiodic tasks exist. Second, each system service in WSN platforms needs to be assigned to either a periodic or an aperiodic task in order to provide fully optimal real-time scheduling for given real-time requirements of WSN applications. A case study based on experiments is conducted to illustrate the application and efficiency of the proposed technique in WSN motes equipped with a low-power 8-bit microcontroller.

Abstract This paper presents a communication framework for end‐to‐end seamless connectivity improvement in IEEE802.11‐based wireless home networks. The proposed communication framework incorporates the following two things: a new concept of wireless home network architecture and a new routing technique in an effort to improve wireless communication coverage and end‐to‐end seamless packet delivery respectively. First, the proposed wireless home network architecture based on the End‐to‐end Seamless multi‐hop COnnectivity based on Dual‐mode (ESCOD) integrates infrastructure and ad hoc modes in an IEEE 802.11‐based wireless home network. Second, the Virtual Link Routing (VLR) technique, a kind of ad hoc routing protocols working on the layer 2.5, provides mobile nodes with end‐to‐end seamless connectivity and packet delivery. We compare the performance of VLR with two prominent on‐demand routing protocols for Mobile Ad hoc Networks (MANET), Dynamic Source Routing (DSR) and Ad hoc On demand Distance Vector (AODV), in the ESCOD‐based wireless home network. Experiments show that our communication framework incorporating the VLR technique in the ESCOD‐based wireless home network architecture yields efficient performance in terms of the low failure rate of packet transmission, fast packet transmission time, network throughput, and a wider coverage area of wireless home networks. Copyright © 2007 John Wiley & Sons, Ltd.

The rapid advancement in portable computing platforms and wireless communication technology has led to significant interest in wireless and sensor networks. The topic of Wireless Ad Hoc and Sensor Networks has gained a lot of attention recently due to the increased use of cellular phones with new applications. Tremendous emergence of wireless communication and sensor network technologies are expected and these have become important areas of intense research. We selected best seven papers from ICCCN conference and specially solicited papers for the special issue. ICCCN is a major international forum for presenting original and fundamental advances in the field of Computer Communications and Networks. The acceptance ratio of ICCCN has been in the range of 22–29%. Therefore, we expect that the special issue and topic will be of great importance and interest to the research community of the Wireless Communications and Mobile Computing journal. The first paper by Kim, Park, and Tak proposes a communication framework for end-to-end seamless connectivity improvement in IEEE802.11 based wireless home networks. They propose and evaluate the wireless home network architecture based on the End-to-end Seamless multi-hop Connectivity based on Dual-mode (ESCOD) that exploits the concepts of Wireless Home Network with Access Point with Dual wireless interfaces (WHN-APD). Their experiments show that their communication framework incorporating the Virtual Link Routing technique yields efficient performance. Leguay, Friedman, and Conan in the second paper address the problem of routing in DTNs. They evaluate schemes that turn the problem of routing into one of routing in a virtual space defined by the mobility patterns of nodes. Their main contribution is the validation of a generic routing scheme called MobySpace that uses the formalism of a high-dimensional Euclidean space constructed upon mobility patterns. They have shown that it can be applied to DTN and that it can bring benefits in terms of enhanced bundle delivery and reduced communication costs. The third paper, by Seligman, Fall, and Mundur, proposes a technique, called Storage Routing (SR), which implements congestion and storage management by selecting messages to migrate from local persistent storage at a router to one or more well-connected neighbors (using a set of locally scoped distributed algorithms, possibly incorporating loops that are known to be optimal for some DTN routing scenarios and decouples storage management from global DTN route selection) when congested, and retrieving them when congestion abates. The SR can significantly increase performance as compared with a comparable scenario lacking SR. In the fourth paper, Wang, Dang, and Wu present a survey of analytic studies on the Delay-Tolerant Mobile Sensor Network (DTMSN) aiming to provide a deep understanding of the characteristics of DTMSN and corresponding analytic techniques, and to stimulate further research in this emerging area. They have identified several open research issues and problems based on the unique characteristics of DTMSN and the existing approaches. Lahde, Doering, Pottner, Lammert, and Wolf, in the fifth paper, developed a distributed environment monitoring network called Environmental Monitoring in Metropolitan Area (EMMA) which is based on the DTN approach and can integrated into existing Public Transportation Networks (PTNs) to allow area wide pollution measurements. They introduce the requirements for establishing a mobile and distributed measurement network and present the architecture of EMMA. EMMA can provide a cost-effective alternative to other environmental monitoring systems especially as it is fast and easy to set up. The architecture is based on 802.11 WLAN, so basically any public WLAN hotspot can be used to forward measured data to the evaluation server. The 802.11 WLAN is well suited for communication between sensor nodes attached to the public transportation vehicles in a city according to their experiments. The sixth paper by Zhang and Zhang provides an overview on recent developments including message ferrying, multicast support, inter-region routing, and transport layer issues. They also point out some open research issues and problems to motivate new research and development in this area as there are still many open issues that need to be resolved before the benefits of the DTNs can be fully utilized and be successful. In the last paper, authors propose a secure key management scheme (which is hierarchical and fully distributed) for the locally caching multi-root multi-generation (LCMRMG) MANET routing algorithm. The scheme focuses on how to establish a secure key management service in a LCMRMG MANET by taking advantage of the tree structure and multiple root nature of LCMRMG routing protocol and utilizes LCMRMG's routing mesh tables. They employ threshold cryptography to distribute trust among the roots of a LCMRMG MANET. Their key management service uses proactive secret share update to guard against model-2 adversary. I would like to thank all reviewers for their time and effort with reviewing assigned papers on time and providing invaluable comments and suggestions for authors for improvements with their papers. I hope this special issue will contribute to the advancement of research in Wireless Ad Hoc and Sensor Networks areas.

Abstract A secure key management scheme for the locality caching multi‐root multi‐generation (LCMRMG) MANET routing algorithm is proposed. The scheme takes advantage of the multi‐root nature of LCMRMG and successfully integrates public key, certification and threshold technologies. The scheme is hierarchical and fully distributed. The key management operations are flexible in secure share distribution and scalable well to large MANET. Extensive simulations have shown that the scheme is secure, robust, efficient, and scalable. Copyright © 2007 John Wiley & Sons, Ltd.

Proxy Web caching is commonly implemented to decrease Web access latency, Internet bandwidth costs and origin Web server load. We propose a transparent shareable proxy caching methodology in which the proxy caches maintain a continuously optimal performance with a significant improvement in the cache hit ratio without requiring any additional overhead at the client or at the routers. This approach allows caches' to be personalized based on the users' Web access patterns. Our approach employs four light weight intelligent agents in a system of proxy caches which use classification algorithms, data mining techniques and performance monitors to study the client's Web access patterns and configure caches to best serve the clients with available resources. These agents run with predictable run times with an optimal use of computer resources.

We have researched the key functional and operational support architecture in IP-based packet voice and video (V2) telecommunication services. This paper summarizes solutions to a number of challenges that the telecom industry has to answer in order to rollout carrier-grade services capability with mass-market acceptance. With a main focus on incorporating the architecture solutions and feature capabilities, we have developed next-generation V2 over IP telecom solution architecture with interoperability and transformation as the key objectives. Advantages of our architecture solutions include meeting legacy service expectation, providing distinctive network and service management, as well as facilitating across telecom industry integration with a uniform approach.

When a traffic demand is changed, a virtual topology could be reconfigured to serve that traffic and to retain high performance. We purpose a reconfiguration model that minimizes costly changes in a virtual topology and maximizes network performance for a series of reconfigurations in the long term. The model includes the reconfiguration process and the policy. The reconfiguration process finds a set of non-dominated solutions using the multi-objective evolutionary algorithm (MOEA) that optimizes two objectives by using the concept of Pareto optimal. The policy picks a solution from the set of solutions above using the Markov decision process (MDP). A case study based on simulation experiments is conducted to illustrate the application of our model.

Restoration techniques available in the literature have not addressed their performance in terms of significant, multiple objective goals. Some of these methods have shown good performance for a single objective function. However, restoration must consider a number of objective functions. We evaluate existing models and their performance in an attempt to verify their performance and efficacy based on the literature. Our research has found not only inefficiency in some of these methods of restoration, but a general incompatibility. Consequently, This work proposes eight objective functions that yield objective goals significant to the optimal design of a WDM (wavelength division multiplexing) optical network. Each objective function model is presented and is examined by experimentation. Four proposed restoration algorithms are evaluated: KSDPR (k-shortest disjoint path restoration based on multiple uphill moves and heuristic rule), DCROS (deep conjectural reinforced optimal search), RWWA (random walk-based wavelength assignment), and PTCI (physical topology connectivity increase). Numerical results obtained by experimental evaluation of KSDPR, DCROS, RWWA, and PTCI algorithms confirm that MTWM (objective function of minimizing total wavelengths with multi-objective goals) based on the DCROS algorithm is a technique for efficient restoration in WDM optical networks.

Peer-to-peer (P2P) systems and Semantic Web are two novel technologies that face a lot of shortcomings if considered as isolated paradigms. We present an approach that utilizes ontologies to set up a peer profile containing all the data, necessary for peer-to-peer interoperability. Using this profile can help eliminate some major issues persistent in current P2P networks, such as security, resource aggregation, group management. We also consider applications of peer profiling for Semantic Web built on P2P networks, such as an improved semantic search for resources, not explicitly published on the Web, but available in a P2P system. We develop the ontology-based peer profile in RDF format and demonstrate its manifold benefits for peer communication and knowledge discovery in both P2P networks and Semantic Web.

This paper studies a traffic grooming in wavelength-division multiplexing (WDM) mesh networks for the SONET/SDH streams requested between node pairs. The traffic could be groomed at the access node before converting to an optical signal carried in the all-optical network. We design a virtual topology with a given physical topology to satisfy multiple objectives and constraints. The grooming problem of a static demand is considered as an optimization problem. The algorithms found in the literatures focus on a single objective either to maximize the performance or to minimize the cost. We propose a multiobjective evolutionary algorithm to solve a grooming problem that optimizes multiple objectives all together at the same time. In this paper we consider the optimization of three objectives: maximize the traffic throughput, minimize the number of transceivers, and minimize the average propagation delay or average hop counts. The simulation results show that our approach is superior to an existing heuristic approaches for the 6-node benchmark network in an acceptable running time.

Abstract As Internet business exponentially grows, a need for the high security level categories that identify a group of connections or an individual transaction is manifest. Recently the development of efficient and secure software architecture has been in high demand. In this paper, we propose adaptive secure software architecture to support secure e‐commerce transactions. Our adaptive secure software architecture dynamically adapts security classes based on the nature and sensitivity of interactions among participants. Four security classes incorporate security levels of cryptographic techniques with a degree of information sensitivity. We have done extensive experiments on the performance of the proposed adaptive secure software architecture. Experimental results show that our adaptive secure software architecture provides e‐commerce transactions with high‐quality security services. Copyright © 2003 John Wiley & Sons, Ltd.

Emerging peer-to-peer computing provides new possibilities but also challenges for distributed applications. Despite their significant potential, current peer-to-peer networks lack efficient knowledge discovery and management. This paper addresses this deficiency and proposes the Intelligent File Sharing framework, which provides an effective and flexible query for P2P file sharing. The IFS is based on powerful schema and flexible inference, as well as efficiently integrated and extensible retrieval algorithms. Experimental results have provided evidence of the high performance and scalability of the Intelligent File Sharing (IFS) system in peer-to-peer environments.

In our optical network design method, design of the logical topology is preceded by routing and wavelength assignment. The logical topology is a set of lightpaths formed to serve traffic demands. It must be flexible and robust for future changes or reconfiguration while also minimizing the cost and optimizing some objective functions. These features can be found in a multi-layer architecture. In an optical network, this architecture includes service layer, electrical layer and optical layer, where the optical layer serves as the backbone of the lower layers. Moreover, the equipment at optical nodes, such as optical cross connect (OXC), cannot serve all demands in the traffic demand matrix (e.g., the set of lightpaths is limited by the number of transmitters and receivers). Some nodes and lightpaths are preselected and form the optical network in the optical layer of the multi-layer architecture. We show an approach to multi-layer optical network design by analyzing the traffic demand matrix and physical topology in order to classify nodes into either optical layer or electrical layer using a clustering method and then design the logical topology to reach a certain limitation and objective function. Our multi-layer approach reduces the size of the optical network, resulting in lower cost of equipment and fewer constraints in the design. Besides, the clustering method provides a multivariate analysis to cluster the data by combination of network node characteristics, and can be extended to the financial cost of equipment, location data or even policy data.

We propose a software framework for non-repudiation service in e-commerce (electronic commerce) on the Internet. The proposed software framework is an explicit security framework for notary service. In the framework we propose a systematic design methodology that provides a security class concept. Our framework can be differentiated from others. First, unlike other frameworks, it is interested in a successful completion of e-commerce transactions by supporting non-repudiation of service. Second, the proposed framework is based on dynamic adaptive mechanism that improves the performance of e-commerce transactions.

Rapid advances in the world of high-speed optical network and high-speed electronic routing has led to consideration of advanced models such as genetic algorithms (GAs). GAs have proved to be a practical and robust optimization and search tool for network design. However, a GA is not generally employed in traffic grooming over mesh networks. In this paper, we propose a new GA model to handle the traffic grooming problem in an all-optical WDM mesh network. The new model extends classical GAs with heuristic approach to support network cost optimization for combining multiple traffic streams into a single lightpath. In addition, to support our new GA model, we have developed a set of new investigation including position-based bit matrix encoding, genetic heuristic operators, and fitness evaluation function using the clustering method. The experimental results show that our GA model is superior to traditional heuristic approaches for the 5, 6 and 14-node benchmark networks.

Dynamic and complex computation in the area of Geographic Information System (GIS) or Mobile Computing System involves huge amount of spatial objects such as points, boxes, polygons, etc and requires a scalable data structure and an efficient management tool for this information. In this paper, for a dynamic management of spatial objects, we construct a hierarchical dynamic data structure, called an IST/OPG hierarchy, which may overcome some limitations of existing Spatial Access Methods (SAMs). The hierarchy is constructed by combining three primary components: (1) Minimum Boundary Rectangle (MBR), which is the most widely used method among SAMs; (2) the population-based domain slicing, which is modified from the Grid File [14]; (3) extended optimal Integer Searching algorithm [4]. For dynamic management of spatial objects in the IST/OPG hierarchy, a number of primary and supplementary operations are introduced. This paper includes a comparative analysis of our approach with previous SAMs, such as R-Tree, R+-Tree and R*-Tree and QSF-Tree. The results of analysis show that our approach is better than other SAMs in construction and query time and space requirements. Specifically, for a given search domain with n objects, our query operations yield $O($ \scriptsize $\sqrt {\frac {\log n} {\log\log n}}$\normalsize $)$ compared to $O(\log n)$ of the fast SAM and an IST/OPG hierarchy containing $n$ objects can be constructed in $O(n$ \scriptsize $\sqrt {\frac {\log n}{\log\log n}}$\normalsize $)$ time and O(n) space.

We have developed a new ATM integrated switching system(AISS) with workstation system (WS) and analyze it for queue centers using PDQ (pretty damn quick) simulator. The workstation system in AISS can be negotiated between ATM switch module (ASM) and client system module (CSM). The overhead and improvement of the performance of the WS in AISS are analyzed. To apply this performance analysis, we develop a performance queuing network model for the AISS system with WS. There are several different kinds of queue centers: srosd, hmilpd, oc, sa, etc. We obtain the queue length (Q/sub k/(N),) for each queue center and compare the Q/sub k/(N) values. We analyze the relative queue length (Q/sub k/(N)) and find the bottleneck point of AISS system. In order to improve the performance for the bottleneck queue centers, MMFS (memory mapped file system) is utilized here. As a result of measuring the queue length through changing the number of clients, the oc queue center shows a correlation to the number of clients. The results of the performance measurements detected for those bottlenecks at oc queuing center reduces 2.5 times by using the MMFS.

As Internet business exponentially grows, the need for high security level categories to identify groups of connections or individual transactions is manifest. The development of an efficient and secure communication protocol seems to be highly demanding. We propose the adaptive secure protocol to support secure E-commerce transactions. Our adaptive secure protocol dynamically adapts the security level based on the nature and sensitivity of the interactions among participants. The security class incorporates the security level of cryptographic techniques with a degree of information sensitivity. We implement the adaptive secure protocol and measure its performance. The experimental results show that the adaptive secure protocol provides E-commerce transactions with high quality of security service.

As an increasing number of people communicate and collaborate computationally over the Internet, the need for a collaborative environment that facilitates secure and reliable access to large quantities of distributed resources has become manifest. However the breadth of resource distribution makes it difficult for Internet users to acquire the necessary resources for collaborative computing. We have developed a framework for an efficient infrastructure that provides a reasonable mapping between users and resources distributed over the Internet. The proposed framework contributes: an authority mechanism that can be applied to independent and widely distributed resource-providers; a resource hierarchy for partitioning global resource spaces into manageable subspaces; and systematic management of dynamic groups of users and resources running on different sites. This paper describes the schema and processes for resource partition, mapping, negotiation, and forming a resource domain in our framework.

Currently public networks have an enormous number of computers capable of providing many services. Autonomous mobile agents are being used to access their information sources. These agents are modeled in the context of network simulation as mobile network processes. The paper demonstrates that distributed mobile agents can be simulated effectively using C++ over CSIM. C++ over CSIM achieves the clarity and logic of agent based simulation for network services. Inheritance and specialization under object orientation allow the design and reuse of simulation objects. This combination facilitates rather straightforward simulation designs that are scalable, accurate, flexible and generalizable. The design for such large scale simulation is sketched and the run time behavior of the simulator is analyzed.

The management of multimedia information poses special requirements for multimedia information systems. Both representation and retrieval of the complex and multifaceted multimedia data are not easily handled with the flat relational model and require new data models. In the last several years, object-oriented and graph-based data models are actively pursued approaches for handling the multimedia information. In this paper the characteristics of the novel graph-based object-oriented data model are presented. This model represents the structural and behavioral aspects of data that form multimedia information systems. It also provides for handling the continuously changing user requirements and the complexity of the schema and data representation in multimedia information systems using the schema versioning approach and perspective version abstraction.

With the explosive growth of the size of databases, many knowledge discovery applications deal with large quantities of data. There is an urgent need to develop methodologies which will allow the applications to focus search to a potentially interesting and relevant portion of the data, which can reduce the computational complexity of the knowledge discovery process and improve the interestingness of discovered knowledge. Previous work on semantic query optimization, which is an approach to take advantage of domain knowledge for query optimization, has demonstrated that significant cost reduction can be achieved by reformulating a query into a less expensive yet equivalent query which produces the same answer as the original one. In this paper, we introduce a method to utilize three types of domain knowledge in reducing the cost of finding a potentially interesting and relevant portion of the data while improving the quality of discovered knowledge. In addition, we propose a method to select relevant domain knowledge without an exhaustive search of all domain knowledge. The contribution of this paper is that we lay out a general framework for using domain knowledge in the knowledge discovery process effectively by providing guidelines.

The robustness of TCP has contributed to its success in the Internet environment. The role of communications is already well-established in the office environment. With the advent of cheap, affordable broadband communications and the increasing complexity of consumer goods, it seems natural to extend the network into homes. In-home networking means a high-speed communication among the digital appliances within a home. Introduction of applications over high-speed home networks using the TCP/IP protocol is increasing. The integrated environment of Internet and home network is demanding as well. We have validated a TCP model over a high-speed home network environment, investigated the throughput behavior of TCP over IEEE 1394 home networks, and evaluated a potential solution for high performance of TCP over IEEE 1394 home networks. The simulation model has produced several interesting results in the performance of TCP over IEEE 1394 home networks.

This paper studies the behavior for performance evaluation of a personal communication services (PCS) network, in which the handoff call arrival processes and the new call arrival processes may depend on the number of calls in the target cells, and the caller may become impatient. We propose an analytical model and obtain the expressions of some interesting conventional and some new performance measures. Many special cases of our model used in previous traffic models of wireless and/or wireline communications are discussed. The results presented in this paper can provide guidelines for field data processing on updated PCS network design and performance evaluation.

Communication via computer networks has been growing rapidly. Technology has gained momentum. Industry, international organizations, and businesses, have started relying on networks to provide reliable, supportive, fast, and easy methods to maintain transactions between their branches. Issues such as bandwidth, scalability, and efficiency became pertinent parameters that had to be configured at all costs. Also, information needs to be sent from one site to several sites. All of this is happening on packet switched networks. With the introduction of asynchronous transfer mode (ATM), the speed and quality of service of networks have increased tremendously. Still, the necessity of sending one information to several sites instantaneously has been unresolved. This research paper broadens this perspective, and introduces a new architecture for the future that will enable multicast routers to route packets. This paper also reviews the current state of multicast protocols, highlights the missing features, motivates the design, and develops the enhanced multicast protocols. A new architecture is based upon a hybrid system of distributed databases and a centralized server. Simulation and results of the proposed architecture are also described in detail.

We analyze a simple non-repudiation protocol for personal communication systems employing a one way function that establishes trust between the mobile unit and visiting location register. The security of the protocol is analyzed and a traffic analysis is performed indicating that the protocol's message overhead during call origination is tolerable to network traffic under various cell densities and traversal velocities ranging from pedestrian to vehicular speeds. The message penalty is under 15% of total control traffic for registration, origination and termination call phases at vehicular speeds with an origination rate of 5.6 calls per handset per hour. The penalty for pedestrian traffic with high origination rate is higher at 23% of total control traffic.

Article Free Access Share on Intensional query processing using data mining approaches Authors: S. C. Yoon Dept. of Computer Science, Widener University, Chester, PA Dept. of Computer Science, Widener University, Chester, PAView Profile , I. Y. Song College of Information Studies, Drexel University, Philadelphia, PA College of Information Studies, Drexel University, Philadelphia, PAView Profile , E. K. Park Dept. of Software Architecture, University of Missouri, Kansas City, MO Dept. of Software Architecture, University of Missouri, Kansas City, MOView Profile Authors Info & Claims CIKM '97: Proceedings of the sixth international conference on Information and knowledge managementJanuary 1997 Pages 201–208https://doi.org/10.1145/266714.266896Published:01 January 1997Publication History 2citation383DownloadsMetricsTotal Citations2Total Downloads383Last 12 Months4Last 6 weeks0 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

The application of protocol filtering in network modeling was discussed. This technique can be used to conduct performance analysis by simulating system "what-if" scenarios. The Windows NT and Novell Netware subnets of the School of Engineering at Widener University were considered as the problem domain. Analysis was conducted on 1.2 GB of data gathered daily over a period of two months by a network monitor. Protocol models built for NCP, SAP, RIP, IPX NetBIOS, UDP Broadcasts, TCP, Telnet, ARP, SMB, IBMNB, NetBIOS NS, AARP, RTMP, and NBP. Identification of different types of protocol traffic in association with source and destination was effected through customized packet filtering. Thereafter, traffic models were built for interarrival time and packet size. After extensive testing of the simulation output, what-if scenarios were setup and addressed. One such scenario involved the addition of ten workstations to an existing subnet. Another variant was to consider a new subnet containing ten workstations. The simulation output has been verified against an external criterion.

The problem of determining whether two programs compute the same function is undecidable. We restrict the class of functions that a program can compute to be a finite dimensional vector space, enabling the problem to become tractable. We prove a theorem showing that the number of test points needed to distinguish any such programs is equal to the dimension of the vector space of functions which they compute, thus generalizing previous results of Howden. Our result unifies certain existing software testing theory and explains the successes and failures of one existing method for selecting test data called perturbation testing. We apply the theorem to obtain three results on the number of test points required to test in vector spaces of Boolean functions and polynomials. First, the Vandermonde matrix used together with our theorem yields the classical result that a polynomial of degree at most n is determined by n+1 points. Second, in vector spaces of Boolean functions we obtain useful results when the degree of the Boolean function is less than the number of inputs to the function. Third, we apply our theorem to describe a technique for testing nonpolynomial, real valued functions.

Article Semantic query processing in object-oriented databases using deductive approach Share on Authors: S. C. Yoon Dept. of Computer Science, Widener University, Chester, PA Dept. of Computer Science, Widener University, Chester, PAView Profile , I. Y. Song College of Information Studies, Drexel University, Philadelphia, PA College of Information Studies, Drexel University, Philadelphia, PAView Profile , E. K. Park Dept. of Computer Science, U.S. Naval Academy, Annapolis, MD Dept. of Computer Science, U.S. Naval Academy, Annapolis, MDView Profile Authors Info & Claims CIKM '95: Proceedings of the fourth international conference on Information and knowledge managementDecember 1995 Pages 150–157https://doi.org/10.1145/221270.221365Online:02 December 1995Publication History 12citation445DownloadsMetricsTotal Citations12Total Downloads445Last 12 Months4Last 6 weeks0 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access

Within many organizations the number of databases containing classified or otherwise sensitive data is increasing rapidly. Access to these databases must be restricted and controlled to limit the unauthorized disclosure, or malicious modification of data contained in them. However, the conventional models of authorization that have been designed for database systems supporting the hierarchical, network and relational models of data do not provide adequate mechanisms to support controlled access of temporal objects and context based temporal information. In this paper we extend the multilevel secure relational model to capture the functionality required of a temporal database, i.e. a database that supports some aspect of time, not counting user-defined time. In particular we assign class access to bitemporal timestamped attributes, and give explicit security classifications to temporal elements.

In the near future, we believe that we will need much more sophisticated answer-finding schemes in an object-oriented database in order to satisfy the needs of truly intelligent information system. In this paper, we introduce a method to apply the intensional query processing techniques of deductive databases to object-oriented databases. So, we can generate intensional answers to represent answer-set abstractly for a given query in object-oriented databases.

In a distributed system of N sites an efficient solution to the critical section problem is proposed to allow multiple simultaneous entries to the Critical Section. The proposed solution is token-based, deadlock-free and free from starvation. In all cases except during the book keeping cycle of the algorithm, the number of message exchanges per Critical Section execution is less than or equal to 5. Only during the book keeping cycle which is not done very often the number of message exchanges per Critical Section execution reaches to at most N.

Existing Geographic Information Systems lack many impor-tant features such as the ability to model the real world more adequately and facilities for logical deduction and ge-ometric computation. In this paper, we study the structure and behavior of existing Geographic Information Systems, isolate their drawbacks and explore the applicability of ob-ject oriented design, logical deduction and hypermedia to developing better and more efficient geographic information systems. In particular, we focus on the concept, design and development of an architecture for the next generation ge-ographic information systems, which will be able to access, synthesize and reason about large volumes of geographic in-formation more efficiently and effectively, without sacrificing functionality, extensibility and consistency. Of significance is the integration of many diverse forms of technological ad-vancements, including object oriented design, expert sys-tems and multi-media systems.

Abstract The acceptance of the C programming language by academia and industry is partially responsible for the ‘software crisis’. The simple, trusting semantics of C mask many common faults, such as range violations, which would be detected and reported at run‐time by programs coded in a robust language such as Ada. Ada is a registered trademark of the U.S. Government (Ada Joint Program Office) This needlessly complicates the debugging of C programs. Although the assert macro lets programmers add run‐time consistency checks to their programs, the number of instantiations of this macro needed to make a C program robust makes it highly unlikely that any programmer could correctly perform the task. We make some unobtrusive extensions to the C language which support the efficient detection of faults at run‐time without reducing the readability of the source code. Examples of the extensions are automatic checking of error codes returned by library routines, constrained subtypes and detection of references to uninitialized and/or non‐existent array elements.

The design of a set of Ada packages defining parallel data types is described. The parallel data types and operations defined on them are intended to provide natural Ada constructs for exploitation of the data parallel Connection Machine (CM). The preliminary design of this CM interface to be built in Ada provides data parallel operations equivalent to operations found in the CM *LISP programming language and preserves many of the inherent advantages of the Ada language. Package specifications for the packages constituting the interface have been written and compiled with the VAX/VMS Ada compiler. Implementation concepts are described and samples of Ada application code are shown. While the interface is intended for use with the Connection Machine, the basic concepts may apply to other SIMD (single instruction/multiple data) machines such as the MasPar MP-1 and DAP.>