|
SIWN Abstracts Index
sai: cosiwn.2009.04.011 KITFramework: A Framework Architecture For Supporting Knowledge-Intensive Processes Daniela Feldkamp Communications of SIWN, Vol. 6, April 2009, pp. 1-7 Abstract: Automating and supporting business processes is still a challenge as they are usually knowledge-intensive, can only be planned to a limited degree, but are compliance relevant. For well-structured processes workflow management systems are mainly useful and efficient. However, they lack flexibility in knowledge-intensive process parts. To cope with increasing changes, uncertainty and unpredictability they have to be more flexible and adaptable. Several approaches exist focusing on a specific problem (e.g. flexible resource allocation, consistency checking, context-relevant decision support and variable process planning) to support knowledge-intensive processes. To combine the advantages of well-structured processes with the demand of adaptivity and flexibility the paper introduces a framework combining the benefits of the workflow management systems and service-oriented architecture (SOA). Keywords: BPEL, Workflow Engine, Knowledge-Intensive Process, Framework, SOA
sai: cosiwn.2009.04.012 Autonomous Cooperation in Multi-Agent Systems Using Answer Set Programming René Pázman Communications of SIWN, Vol. 6, April 2009, pp. 8-15 Abstract: Multi-agent systems (MAS) offer a way to tackle complex (distributed) problems in heterogeneous environments. A need for autonomous cooperation is apparent especially for Open MAS (e.g. for e-business), where heterogeneous agents developed by various designers can join the system at any time and have means to securely interact with each other. This paper provides a framework, based on answer set programming (ASP), for specifications of cooperation protocols and agents, where agents can evaluate consequences of joining cooperation specified by a protocol and make decisions whether to cooperate, based on their private goals. Keywords: answer set programming, autonomous agents, cooperation protocols, e-business, open multi-agent systems.
sai: cosiwn.2009.04.013 Grid-Based Information Retrieval Solution for the Aggregation of Legal Datasets in Online Dispute Resolution Ather Saeed, Andrew Stranieri, Richard Dazeley and Liping Ma Communications of SIWN, Vol. 6, April 2009, pp. 16-22 Abstract: The Web is a stateless and complex environment when it comes to the retrieval of information from millions of computers connected to the Internet via WWW servers. Information Retrieval (IR) from heterogeneous data sources poses a great challenge as the information of interest is stored in a variety of different formats. Answering an enormous amount of queries is a resource and computational intensive task in ODR (Online Dispute Resolution). Information availability also poses a challenge when it comes to the mediation and arbitration processes in resolving eCommerce and legal disputes. A new Grid-based information retrieval model is proposed for the aggregation and replication of legal datasets from remote machines with indexed-based search facility. Datasets of interests will be indexed with a slight modification to the existing indexing scheme. A new strategy is proposed to deal with similar queries posted over and over again and how the commonality among the XML query trees are exploited and merged for the efficient retrieval of information. Keywords: Grid computing, IR, Inverted Index, AJAXmashups and ODR
sai: cosiwn.2009.04.014 Efficiency of Transport Collaboration Mechanisms Melanie Bloos and Herbert Kopfer Communications of SIWN, Vol. 6, April 2009, pp. 23-28 Abstract: Horizontal cooperation between road haulage contractors is well established in practice. However, over time many cooperations were subject to transformational processes that led their organizations to merge. Here, a concept of collaborative planning, operational transport collaboration, is discussed. This concept achieves higher degrees of organizational autonomy for the participants of cooperation. The idea behind operational transport collaboration is an exchange of transportation requests in order to create competitive advantages in terms of cost and flexibility. For this exchange, mechanisms have to be found that create the best possible allocation of transportation requests to road haulage contractors. Criteria which mechanisms have to comply with in order to create beneficial and desirable solutions for all participants despite the situation of asymmetric information and strategic behavior are derived from microeconomics and game theory. Combinatorial auctions are then discussed as one means of fulfilling these criteria. Keywords: transport cooperation, exchange mechanism, game theory, microeconomics, combinatorial auction
sai: cosiwn.2009.04.015 AQMIS: An Adaptive Querying Prototype for Mobile Information Systems Dana Al Kukhun, Bouchra Soukkarieh, Corinne Zayani and Florence Sèdes Communications of SIWN, Vol. 6, April 2009, pp. 29-35 Abstract: Nowadays, with Mobile Information Systems (MIS), users in general, and business men in particular, move around new environments while being accompanied by systems that take their location into consideration. In this paper, we present a prototype (AQMIS) that returns to the user a set of semi-structured documents (existing in an organization’s database). Our prototype return adapted documents that meet the user profile (interest, location, etc.). In order to realize this step, we allow the user to request several types of queries that concern his interests and/or the desired location. In order to realize the adaptation process, we propose a mechanism that combines user interests (about the content of returned documents) and his location interests in order to return adapted results. This adaptation process aims to reduce the cognitive overload in mobility. Keywords: adaptation, mobile querying, XML, locationawareness, user’s interests.
sai: cosiwn.2009.04.016 A Framework for Aggregation and Validation of Hierarchical Service Level Agreements Irfan Ul Haq, Altaf Ahmed Huqqani, and Erich Schikuta Communications of SIWN, Vol. 6, April 2009, pp. 36-41 Abstract: Novel business scenarios such as Business Value Networks and Extended Enterprizes pose new challenges to enable service value chains across heterogeneous organizational boundaries. In these business scenarios, service choreographies result into hierarchical structures of added value. Service Level Agreements (SLAs), which are contracts between consumers and providers, guarantee the expected quality of service (QoS) to different stake holders at various levels in this hierarchy. So far, the aggregation of SLAs has been treated as a single layer composition. Therefore, we address the strong requirement of describing, modeling and maintaining this hierarchical SLA aggregation associated with service value chains. In this paper we propose a framework to enable hierarchical SLA choreography, aggregation, and validation for business value networks. Keywords: SLA Aggregation, Service Choreography, SLA Validation, Business Value Networks.
sai: cosiwn.2009.04.017 Model-driven Server Allocation in Distributed Enterprise Systems James W.J. Xue, Adam P. Chester, Ligang He and Stephen A. Jarvis Communications of SIWN, Vol. 6, April 2009, pp. 42-50 Abstract: Internet service providers (ISPs) usually use several server pools to host different web applications, to ensure smooth system management and minimum interference between applications. The workload demand in each of the pools can vary dramatically due to a number of factors, including timing and the types of the hosted applications. Therefore, it is desirable that servers should be able to switch between pools to optimise resource usage and maximise company revenue. Internet applications can be modelled as multi-tier queueing networks, with each network station corresponding to each application tier. The advantage of using an analytical model is that performance metrics can be easily computed, and potential system bottlenecks can be identified without running the actual system. In this paper, an analytical model is used to assist dynamic resource allocation in server pools. In addition, an admission control scheme is also used to deal with system overloading. Performance evaluation is conducted via simulation and the experimental results show the benefits of our approach for various workload scenarios. Keywords: Multi-tier, queueing network, bottleneck, server switching, revenue.
sai: cosiwn.2009.04.018 An Overview of Declarative Process Modeling Principles and Languages Stijn Goedertier and Jan Vanthienen Communications of SIWN, Vol. 6, April 2009, pp. 51-58 Abstract: Business process models needs to fulfill a number of requirements to be useful when designing, implementing, enacting, and analyzing business processes. In general, they must contribute to process flexibility, compliance, efficiency, and effectiveness, but this is a general requirement, which merely reflects the main goals of business process management. The real challenge for business process models consists of providing information systems with adequate information to deal with the often conflicting requirements of flexibility and compliance. A declarative approach to process modeling is likely to be capable of providing adequate information. The reason is that declarative processmodels explicitly reflect the underlying business concerns that govern business processes. An explicit awareness of these underlying business concerns allows to balance flexibility and compliance requirements, both at runtime and design-time. This paper further characterizes declarative process modeling and provides an overview of existing languages. Keywords: process modeling principles, modeling languages, declarative process modeling.
sai: cosiwn.2009.04.019 Cataract Screening by Specular Reflection and Texture Analysis Retno Supriyanti, Hitoshi Habe, Masatsugu Kidode and Satoru Nagata Communications of SIWN, Vol. 6, April 2009, pp. 59-64 Abstract: The increasing number of cataract sufferers is a serious problem because cataracts are the leading cause of blindness in the world. To avoid blindness from cataracts we need to detect them early. In previous research, we proposed a new method for cataract screening. This method is based on the appearance of specular reflection inside the pupil. Referring to the reflection theorem, normal eye images will have two kinds of reflection inside the pupil, while cataract eye images have one reflection and both of them are always in a line. Therefore we can distinguish between cataract and normal eye images. However, sometimes we face problems distinguishing between specular reflection and whitish color if it is located in the same line. This is a critical problem for the screening result. In this paper we propose an improved method for handling such problems by extracting texture uniformity inside the pupil. The result shows that the percentage value of True Positive is 91:24% and the percentage value of False Positive is 30%. Keywords: cataract, specular reflection, texture uniformity, screening
sai: cosiwn.2009.04.020 Myxobacteria Motility: A Novel 3D Model of Rippling Behaviour in Myxococcus xanthus Antony B. Holmes, Sara Kalvala and David E. Whitworth Communications of SIWN, Vol. 6, April 2009, pp. 65-70 Abstract: Bacterial populations provide interesting examples of how relatively simple signalling mechanisms can result in complex behaviour of the colony. A well studied example of this phenomenon can be found in myxobacteria; cells can coordinate themselves to form intricate rippling patterns and fruiting bodies using localised signalling. Our work attempts to understand and model this emergent behaviour. We developed an off-lattice Monte Carlo simulation of ripple formation using a using a software framework we have created and show how rippling is a consequence of the combined effect of cell biochemistry and cell physics. Keywords: monte carlo, morphogenesis, myxobacteria, rippling.
sai: cosiwn.2009.04.021 Sum-Linear Blosum: A Novel Protein Encoding Method for Secondary Structure Prediction Giuliano Armano, Filippo Ledda and Eloisa Vargiu Communications of SIWN, Vol. 6, April 2009, pp. 71-77 Abstract: It is widely acknowledged that encoding methods play a fundamental role in the field of protein secondary structure prediction, their task being to transform the available biological information in a form directly usable by the underlying predictor. This transformation is particularly critical, as the relationship between primary and secondary structure is very subtle and difficult to capture. In this paper we compare three different encoding methods and introduce a new encoding which we show to be superior. Experiments have been performed with a software architecture devised to guarantee the statistical significance of the results. The current release of the predictor is freely usable through the online web interface at http://iasc2.diee.unica.it/ssp. The corresponding stand alone application (together with the data sets used for benchmarking purposes), as well as the source listing (in Java) of the GAME generic architecture used to implement the predictor, can be downloaded from the main page of the web interface. The software provided in source format can be freely distributed under the GPL license. The proposed method has been compared with other state-of-the-art encoding methods, and experimental results confirm its superiority. In particular, we obtained an improvement that ranges from 0.5 to 1.5%, measured both by Q3 and SOV performance indexes. Keywords: proteomics, protein sequence analysis, secondary structure prediction
sai: cosiwn.2009.04.022 Betweenness Centrality Computation – A New Way for Analyzing the Biological Systems Răzvan Bocu, Sabin Tăbîrcă Communications of SIWN, Vol. 6, April 2009, pp. 78-84 Abstract: The study of proteomics reached unexpected levels of interest, as a direct consequence of its discovered influence over some complex biological phenomena, such as problematic diseases like cancer. This paper proposes a new way of analyzing the networks of proteins (interactome networks), by computing the betweenness centrality measure. This allows for an accurate detection of sub-communities belonging to the whole known proteome and, thus, resulting an easier and more accurate analysis of the network’s properties. The paper introduces the concept of betweenness centrality, and then describes how betweenness computation can help the interactome network analysis. Three generic algorithms for betweenness computation are described and their performance tested against real biological data, which is part of the IntAct dataset. Keywords: Betweenness centrality, interactome networks, protein-protein interactions, sub-communities, IntAct.
sai: cosiwn.2009.04.023 Opportunities and Limitations of a Principal Component Analysis Optimized Machine Learning Approach for the Identification and Classification of Cancer Involved Proteins Markus Borschbach, Sascha Hauke, Martin Pyka and Dominik Heider Communications of SIWN, Vol. 6, April 2009, pp. 85-89 Abstract: The computational reduction of the input dimension of different parts of the input layer for the prediction of functional protein classes is presented. The proteins are preprocessed and two feed forward neural networks were trained with a dataset containing small GTPases and non-GTPases. The results of the principle component analysis (PCA) optimized neural network and the neural network without PCA were compared. The computational complexity and the prediction accuracy are key aspects of the discussion of the statistical verified simulation results. Moreover, the mathematical background of the PCA and therefore the influence of the PCAdimension on the prediction quality as an underlying optimization problem based on the necessary selection of eigenvectors of the feature space is considered. Keywords: PCA, neural networks, Soft Computing, cancer, protein structure, protein function.
sai: cosiwn.2009.04.024 Multi-Regional Analysis of Contact Maps Towards Locating Common Substructural Patterns of Proteins Hazem R. Ahmed and Janice I. Glasgow Communications of SIWN, Vol. 6, April 2009, pp. 90-98 Abstract: 1D protein sequences, 2D contact maps and 3D structures are three different representational levels of detail for proteins. Predicting protein 3D structures from their 1D sequences remains one of the complex challenges of bioinformatics. The “Divide and Conquer” principle is applied in our research to handle this challenge, by dividing it into two separate yet dependent subproblems, using a Case- Based Reasoning (CBR) approach. Firstly, 2D contact maps are predicted from their 1D protein sequences; secondly, 3D protein structures are then predicted from their predicted 2D contact maps. In this paper, we focus on the problem of identifying common substructural patterns of protein contact maps, which could potentially be used as building blocks for a bottom-up approach for protein structure prediction. We further demonstrate how to improve identifying these patterns by combining both protein sequence and structural information. We assess the consistency and the efficiency of identifying common substructural patterns by conducting statistical analyses on several subsets of the experimental results with different sequence and structural information. Keywords: boxplots, case-based reasoning (CBR), contact maps, normalized compression-based distance (NCD), sequence similarity.
sai: cosiwn.2009.04.025 CORAL-T: Heuristic COding Region ALignment Method for Three Genome Sequences Che-Lun Hung, Chun-Yuan Lin, Yeh-Ching Chung, Shu Ju Hsieh and Chuan Yi Tang Communications of SIWN, Vol. 6, April 2009, pp. 99-105 Abstract: Identifying protein coding genes is a challenging task in the computational molecular biology field. With the rapid accumulation of genomic sequences for various organisms, it is now feasible to identify novel genes by genomic comparisons. An increasing number of studies indicated that the three-way alignment can offer additional information or more accurately alignment than the pair-wise alignment does. Therefore, we propose a method, CORAL-T, a heuristic coding regions alignment method for three genome sequences. CORAL-T adopts a probabilistic filtration model and the local optimal solution to align genome sequences (codon to codon with the wobble mask rule) by the sliding windows and, thus, obtains the nearoptimal alignment in linear time. Experimental results present that CORAL-T is fastest and achieves the comparable results to the dynamic programming-based three-way alignment method and multiple sequence alignment tools, such as ClustalW, MUSCLE and T-COFFEE. Keywords: coding region alignment, sequence alignment, linear time alignment, three-way alignment, probabilistic analysis, computational complexity.
sai: cosiwn.2009.04.026 Phylogenic Reconstruction of Species Using Spectral Content Method Lissy Anto P, Vrinda V. Nair and Achuthsankar S. Nair Communications of SIWN, Vol. 6, April 2009, pp. 106-110 Abstract: Biological information can be revealed by applying digital signal processing techniques to biosequences. In this work, a phylogenetic tree is constructed by measuring the spectral content of amino acid sequences using Discrete Fourier Transform. Amino acid sequences were chosen to find the evolutionary trajectories, as the functions of proteins are decided by these sequences. The spectral content measure yielded a simple method of classification of organisms. When compared with the conventional multiple sequence alignment method, spectral content method provides dimensionality reduction. In this experimentation, the analysis has been done with NADH dehydrogenase subunit1 protein sequences from different organisms. Keywords: discrete fourier transform, multiple sequence alignment, phylogenetic tree, spectral content
sai: cosiwn.2009.04.027 Time Delay and Protein Modulation Analysis in a Model of RNA Silencing Svetoslav Nikolov, Xin Lai, Olaf Wolkenhauer and Julio Vera Communications of SIWN, Vol. 6, April 2009, pp. 111-117 Abstract: RNA silencing is a recently discovered mechanism for posttranscriptional regulation of gene expression. Precisely, in RNA interference, RNAi, endogenous expressed or exogenously induced small RNAs promote and modulate the cleavage of complementary messenger RNA involved in the synthesis of targeted proteins. In this paper we investigated the role of time delay and protein regulation in the posttranslational protein regulation through RNA interference. Towards this end, we used and modified a simple model accounting for RNAi and used qualitative bifurcation analysis, sensitivity analysis and predictive simulations to analyze it. Our results suggest that some processes in the system, like Dicer-mediated mRNA degradation or non specific mRNA degradation, play an important role in the modulation of RNA silencing, whereas silencing seems virtually independent of modulation in other processes. Keywords: Andronov-Hopf bifurcation, delay differential equations, RNA silencing, sensitivity analysis.
sai: cosiwn.2009.04.028 Robust Hierarchical Clustering for Gene Expression Data Analysis Md. Nurul Haque Mollah, Mari Pritchard, Osamu Komori and Shinto Eguchi Communications of SIWN, Vol. 6, April 2009, pp. 118-122 Abstract: Hierarchical clustering algorithms are widely used successful statistical technique for analyzing microarray gene expression data. However, the traditional hierarchical clustering algorithms are not robust against outliers. Therefore, traditional approaches may produce misleading clustering results in presence of outliers. In this paper, an attempt is made to robustify hierarchical clustering algorithm using minimum β- divergence based robust correlation matrix. The performance of the proposed method depends on the value of the tuning parameter β and the initialization of parameters. The proposed method reduces to the traditional hierarchical clustering approach for the tuning parameter β = 0. Simulation results show that the proposed method significantly improves the performance over the traditional hierarchical clustering approach in presence of outliers; otherwise, it keeps almost equal performance. Keywords: Hierarchical clustering, Gene expression data, Correlation matrix, Minimum β-divergence method and Robustness.
sai: cosiwn.2009.04.029 Types and Effects for Service Composition Based Behaviors JunQing Chen and LinPeng Huang Communications of SIWN, Vol. 6, April 2009, pp. 123-126 Abstract: A static approach is proposed for describing behavior consistent service composition. We extend the λ- calculus with primitives for composing services that respect given user requirements, i.e. service behavior consistency. The type and effect system is introduced to automatically infer conservative approximations of service behaviors arising at runtime and can guarantee those discovered and selected services match the behavior consistent requirements. Keywords: behavior consistency, type and effect system, SOC, service composition.
sai: cosiwn.2009.04.030 Clustering Pair and Odd to Optimize the Energy Consumption in Wireless Sensor Networks M. Guerroumi, N. Badache and S. Moussaoui Communications of SIWN, Vol. 6, April 2009, pp. 127-131 Abstract: Considering the importance of energy parameter in wireless sensor networks, an optimal management of this resource is indispensable, especially when we talk about the MAC layer, the layer that is responsible on the significant part of energy consumption caused by the collision, the idle listening and the overhearing. However, the target of the proposal solution is to minimize, as soon as possible, the idle listening by making the sensor nodes follow an optimal program of listen/sleep permitting the avoidance of energy loss and keeping the correct functionality of network. To completely avoid the problem of the collision and the hidden host, a specific configuration has been introduced which organizes the sensor nodes under different clusters during the deployment phase of sensor network. The proposed solution has been evaluated by simulation, its performances evaluation, comparing with other solutions, shown that the energy consumption has been improved, Grace to the mode of send/receive/sleep adopted during the operation phase. Keywords: MAC layer, Collision avoidance, Energy consumption, Wireless sensor network
sai: cosiwn.2009.04.031 Declarative Data Grounding Using a Mapping Language Miguel García, José María A´ lvarez, Diego Berrueta and Luis Polo Communications of SIWN, Vol. 6, April 2009, pp. 132-138 Abstract: Grounding is the process in charge of linking requests and responses of web services with the semantic web services execution platform, and it is the key activity to automate their execution in a real business environment. In this paper, the authors propose a practical solution for data grounding. On the one hand, we define a mapping language to relate data structures from services definition in WSDL documents to concepts, properties and instances of a business domain. On the other hand, two functions that perform the lowering and lifting processes using these mapping specifications are also defined. Keywords: service-oriented architectures, web services, semantic webs, ontologies, data grounding, semantic web services, mapping languages
sai: cosiwn.2009.04.032 A Reengineering Approach for Software Systems Complying with the Utilization of Pervasive Computing Technologies Mohammed Alawairdhi and Hongji Yang Communications of SIWN, Vol. 6, April 2009, pp. 139-143 Abstract: Pervasive technologies available at the current time are considered to be the next big step in business process automation. The change in the business process normally leads to a change in the used information systems. Information systems reengineering is a lengthy task especially when the documentation of a system is lost, outdated or unavailable. In this paper a reengineering framework aiming to assist with the evolution of existing systems to comply with the utilization of pervasive computing technologies is proposed. The overall approach has been presented and discussed. The first stage of the approach has been discussed in details by explaining all its operations. At the end, a case study has been demonstrated to show the effectiveness of the proposed operations of the first stage of the approach. Keywords: reengineering, ubiquitous, pervasive, businesslogic, extracting.
sai: cosiwn.2009.04.033 Security Policies Checking in Distributed Firewalls Using the Mobile Agent Approach Fakher Ben Ftima, Kamel Karoui and Henda Ben Ghezala Communications of SIWN, Vol. 6, April 2009, pp. 144-150 Abstract: There are many challenges confronting the correctness and consistency of security policy configuration in enterprise networks. Firewalls are network security devices that operate based on locally configured policies. A successful deployment of a network security system requires global analysis of policy configurations of all firewalls in order to avoid policy conflicts and inconsistency. Policy conflicts may cause serious security breaches and network vulnerability such as blocking legitimate traffic, permitting unwanted traffic, and insecure data transmission. In this paper, we will check the security policy conflicts that might potentially exist in a single firewall (intra-policy conflicts) or between firewalls (inter-policy conflicts) in a network. To achieve this goal, we will use the mobile agent approach which facilitates communication and data exchange between distributed firewalls. A case study will demonstrate the effectiveness of our approach. Keywords: security policy, firewall, access list, policy conflict, mobile agent.
sai: cosiwn.2009.04.034 An Integration of a High Performance Smartphone with Robotics Using the Bluetooth Technology Haissam El-Aawar and Mohammad Asoud Falah Communications of SIWN, Vol. 6, April 2009, pp. 151-157 Abstract: The aim of this article is to introduce a new approach for controlling a robot using a smartphone via bluetooth connection. The basic idea that is used for this purpose is to use Smartphones instead of PCs to control various applications that need high computational power, which typical microcontrollers cannot perform, and one of these applications is the robotics field. Powered by 32-bit Symbian OS, the series 60 Smartphone (NOKIA 6680) will actually act as the robot’s main brain, where all the complex and heavy calculations, data storage and manipulation will be carried out, as the fully object oriented C++ based Symbian OS provides high level programming capabilities, and the device hardware powered by ARM Microprocessor provides high processing speed and relatively large amount of RAM. This control system is based on two modes; the first is a direct drive mode, in which the robot will directly respond to the user commands of movements and directions, and the second is a map based mode, in which the robot can be moved in an area while interacting with the environment and adopting new changes of obstacles on its way. Keywords: Integration, Control System, Smartphone, Mobile, Bluetooth.
sai: cosiwn.2009.04.035 A Method for Detecting and Avoiding Many-to-Many Relationship in Class Design of Software Object-Oriented Development Yuichi Inoue, Hiroaki Hashiura and Seiichi Komiya Communications of SIWN, Vol. 6, April 2009, pp. 158-165 Abstract: Recently, software based on object-oriented technology is becoming mainstream. Until now, objectoriented software design methods such as OMT (Object Modeling Technique) [7], OOSE (Object Oriented Software Engineering) [3], RUP (Rational Unified Process) [2], etc. have been proposed. However, in these software design methods, there is the problem that clear criteria for performing class design (i.e., elicitation of classes, definition of the association between classes, etc.) does not exist. Therefore we take up the problems of class design every time we design new software. Above all, how to define many-tomany relationships between classes which makes software implementation difficult. In order to improve the quality of object-oriented software design generated by novice software engineers. We propose a solution to this problem. We developed an education support tool which can detect automatically the many-to-many relationship. In this paper, we show the results of testing with this new tool introduced. It shows that novice software engineers of object-oriented technology will get ability to repeat training how to modify the class design including many-to-many relationships. Keywords: class design, object oriented software development, many-to-many relationship, XMI, eclipse
sai: cosiwn.2009.04.036 Energy Consumption Comparison between Autonomous and Central Wireless Sensor Network Amir M Jafari, Adam Sklorz and Walter Lang Communications of SIWN, Vol. 6, April 2009, pp. 166-170 Abstract: In order to implement wireless sensor network in automation process application, two configurations are considered, Autonomous and Central. In this paper these two structures are compared from the energy consumption viewpoint. Central and autonomous networks are simulated by Prowler simulator. In order to simulate the networks, SCAR routing algorithm is implemented in the second section. Prowler is used as simulator which is described in section 3. It is explained how it is modified and which energy model is implemented. In section after 50 random topologies are examined and their average is extracted to make the results independent from the topology. The networks’ and nodes’ energy consumptions are separately monitored to compare their behaviors. The result shows the ratio of central network energy consumption to the autonomous one. It is depicted the nodes’ energy consumption in central network is distributed with higher standard deviation. Based on the result it will be discussed how the autonomous structure is more beneficial. Keywords: wireless sensor network, autonomous network, central network, energy consumption, energy consumption distribution, prowler, sequential coordinate routing algorithm, automation process.
sai: cosiwn.2009.04.037 Integrating Mobile Computing Solutions into Distance Learning Environments Raoul Pascal Pein, Joan Lu and John Birger Stav Communications of SIWN, Vol. 6, April 2009, pp. 171-177 Abstract: This paper assumes that in the near future most students at universities are in possession of a mobile device with the ability to access the world wide web and display multimedia content. Observing the current development trends of mobile hardware, this seems to be justified. Even common mobile phones have multiple wireless communication interfaces and colour displays. More expensive devices are equipped with a large touch screen and are able to play videos in a reasonable quality. It is attempted to exploit this development and enhance the learning experience of students by gradually building up a pervasive computing infrastructure. A design is proposed that offers an open and extensible (distance) learning environment. Flexible standards such as the Hypertext Transfer Protocol (HTTP) for communication and the Extensible Markup Language (XML) for document transfer are used. This design allows to access and modify learning material stored in learning management systems (LMS), multimedia repositories and electronic voting system (EVS) locally and remotely. The supported technology ranges from PCs and laptops to mobile devices. Keywords: mobile devices, education, distance learning, electronic voting system, multimedia, learning management system
sai: cosiwn.2009.04.028 The Effect of Impulsive Noise on V-BLAST Detection Hasan Abu Hilal, Tariq Abu Hilal and Shadi El Hajjar Communications of SIWN, Vol. 6, April 2009, pp. 178-181 Abstract: In wireless communications, a large class of physical phenomenon observed in practical wireless systems exhibit non-Gaussian behavior. In this paper we present the performance of the V-BLAST detection algorithm under impulsive noise channel characterized by middleton’s Class A model with Binary Phase-Shift Keying (BPSK) modulation in the richly scattered Rayleigh-fading multiple-antenna channel. The performance is described by the mean of bit error rate (BER) of the system. We discuss the performance under different antenna configurations and different noise parameters. Keywords: V-BLAST, MIMO, Impulsive noise.
------------------------------------------------------------------------------------- Copyright © 2009 Systemics and Informatics World Network |