A study of the impact of the willingness-to-learn of CAD novice users on their competence development

The notion that ‘attitude drives behavior’ manifests itself in a variety of ways in educational and occupational settings. As applied to CAD competence development, industrial training of novice CAD users on their way to becoming competent CAD users consume a lot of corporate resources. This paper is the third paper in the line of research that attempts to answer the question having to do with what it takes to make a competent CAD user. Specifically, we examine the CAD-specific factors revolving around the trainees’ willingness-to-learn CAD.These factors are analyzed in two stages. At the start of the training, trainees’ initial attitude towards CAD is established by means of a short questionnaire. Afterwards, throughout the training, trainees’ behavior (online and offline practice) is gauged and, in turn, a relation is established to illustrate how this practice leads to the development of CAD-specific skills. For this purpose, another short questionnaire was utilized. Strong correlations were established relating the trainees’ CAD-specific behavior with the CAD-specific outcomes of learning CAD syntax.Furthermore, and in order to assess the quality of the trainees’ learning of CAD, overall competence was monitored throughout the study via performance measures that describe the time it took the trainees to build test models (speed), which reflects upon the ability to learn the syntax of the CAD tool (declarative knowledge). The sophistication of the models is also used as another measure. Correlating the trainees’ character attributes with these assessed measures, it was found that the stronger is the trainees’ will to learn CAD, the stronger is the likelihood to learn faster. Perhaps more importantly, trainees with initial favorable attitude toward CAD were shown to develop increasingly positive behavior that manifested through additional practice and other forms of visible effort.     

An enhanced Web page change detection approach based on limiting similarity computations to elements of same type

This paper describes an efficient Web page detection approach based on restricting the similarity computations between two versions of a given Web page to the nodes with the same HTML tag type. Before performing the similarity computations, the HTML Web page is transformed into an XML-like structure in which a node corresponds to an open-closed HTML tag. Analytical expressions and supporting experimental results are used to quantify the improvements that are made when comparing the proposed approach to the traditional one, which computes the similarities across all nodes of both pages. It is shown that the improvements are highly dependent on the diversity of tags in the page. That is, the more diverse the page is (i.e., contains mixed content of text, images, links, etc.), the greater the improvements are, while the more uniform it is, the lesser they are.     

MDPF: Minimum Distance Packet Forwarding for Search Applications in Mobile Ad Hoc Networks

This paper introduces a message forwarding algorithm for search applications within mobile ad hoc networks that is based on the concept of selecting the nearest node from a set of designated nodes. The algorithm, which is called Minimum Distance Packet Forwarding (MDPF), uses routing information to select the node with the minimum distance. The goal of the proposed algorithm is to minimize the average number of hops taken to reach the node that holds the desired data. Numerical analysis and experimental evaluations using the network simulation software ns2 were performed to derive the lower and upper bounds of the confidence interval for the mean hop count between the source node of the data request, on one hand, and the node that holds the desired data and the last node in the set of search nodes, on the other hand. In the experimental evaluation, the performance of MDPF was compared to that of Random Packet Forwarding (RPF) and Minimal Spanning Tree Forwarding (MSTF). The results agreed with the numerical analysis results and demonstrated that MDPF offers significant hop count savings and smaller delays when compared to RPF and MSTF.     

A multiplatform methodology: developing mobile device applications

When the Electrical and Computer Engineering Department at the American University of Beirut decided to launch a computing course on mobile computing devices, the author designed a course to meet industry requirements and to introduce students to the major platforms used to build practical applications. He dedicated much of Pervasive Computing Systems and Applications, EECE 679, to teaching mobile device application programming through code demonstrations and in-class application building. The course also covered front-end mobile device technologies and back-end infrastructures. Today, many pervasive computing courses focus on research and theory. Those that do deal with developing mobile applications often limit their coverage to a specific platform. This course covers practical and theoretical pervasive computing, lets students acquire hands-on application-building experience in multiple platforms, and acquaints students with recent developments in related technologies and research. The course includes a mix of lectures, code demonstrations, and student presentations.     

A faulty node detection scheme for wireless sensor networks that use data aggregation for transport

This paper presents a faulty node detection approach for wireless sensor networks that aggregate measurement data on their way toward the sink (base station). The approach is based on the idea of commanding sensor nodes on the aggregation paths to temporarily stop including their readings in the received aggregated readings from their upstream neighbors. The scheme is dependent on the ability of the sink to detect faulty nodes through changes in the received aggregated readings at the sink using a Markov Chain Controller (MCC). The algorithm that is run in the sink uses the MCC to assign a state to each sensor node based on transitions that are triggered by receiving aggregated path readings, and accordingly deduces the nodes that may be faulty. The experimental results show at least 98% detection rate at the cost of reasonable detection delays and generated wireless network traffic. Copyright © 2016 John Wiley & Sons, Ltd.     

A cluster-based trust-aware routing protocol for mobile ad hoc networks

Routing protocols are the binding force in mobile ad hoc network (MANETs) since they facilitate communication beyond the wireless transmission range of the nodes. However, the infrastructure-less, pervasive, and distributed nature of MANETs renders them vulnerable to security threats. In this paper, we propose a novel cluster-based trust-aware routing protocol (CBTRP) for MANETs to protect forwarded packets from intermediary malicious nodes. The proposed protocol organizes the network into one-hop disjoint clusters then elects the most qualified and trustworthy nodes to play the role of cluster-heads that are responsible for handling all the routing activities. The proposed CBTRP continuously ensures the trustworthiness of cluster-heads by replacing them as soon as they become malicious and can dynamically update the packet path to avoid malicious routes. We have implemented and simulated the proposed protocol then evaluated its performance compared to the clustered based routing protocol (CBRP) as well as the 2ACK approach. Comparisons and analysis have shown the effectiveness of our proposed scheme.     

Improving vehicular safety message delivery through the implementation of a cognitive vehicular network

The Wireless Access in Vehicular Environments (WAVE) protocol stack has been recently defined to enable vehicular communication on the Dedicated Short Range Communication (DSRC) frequencies. Some recent studies have demonstrated that the WAVE technology might not provide sufficient spectrum for reliable exchange of safety information over congested urban scenarios. In this paper, we address this issue, and present a novel cognitive network architecture in order to dynamically extend the Control Channel (CCH) used by vehicles to transmit safety-related information. To this aim, we propose a cooperative spectrum sensing scheme, through which vehicles can detect available spectrum resources on the 5.8 GHz ISM band along their path, and forward the data to a fixed infrastructure known as Road Side Units (RSUs). We design a novel Fuzzy-Logic based spectrum allocation algorithm, through which the RSUs infer the actual CCH contention conditions, and dynamically extend the CCH bandwidth in network congestion scenarios, by using the vacant frequencies detected by the sensing module. The simulation results reveal the effectiveness of our architecture in providing dynamic and scalable allocation of spectrum resources, and in increasing the performance of safety-related applications.     

Device-aware desktop web page transformation for rendering on handhelds

This paper illustrates a new approach to automatic re-authoring of web pages for rendering on small-screen devices. The approach is based on automatic detection of the device type and screen size from the HTTP request header to render a desktop web page or a transformed one for display on small screen devices, for example, PDAs. Known algorithms (transforms) are employed to reduce the size of page elements, to hide parts of the text, and to transform tables into text while preserving the structural format of the web page. The system comprises a preprocessor that works offline and a just-in-time handler that responds to HTTP requests. The preprocessor employs Cascading Style Sheets (CSS) to set default attributes for the page and prepares it for the handler. The latter is responsible for downsizing graphical elements in the page, converting tables to text, and inserting visibility attributes and JavaScript code to allow the user of the client device to interact with the page and cause parts of the text to disappear or reappear. A system was developed that implements the approach and was used it to collect performance results and conduct usability testing. The importance of the approach lies in its ability to display hidden parts of the web page without having to revisit the server, thus reducing user wait times considerably, saving battery power, and cutting down on wireless network traffic.     

Using group anonymity to hide the identity of VoIP mobile users communicating over hybrid networks while preserving quality of service

Security and privacy have become critical in computer networks, especially with the emergence of E‐commerce. Other than securing the transfer of data, users are interested in protecting their profile privacy against exposure attacks. Multimedia communications are at the core of new information and communication technologies. We seek to achieve end users' profile privacy without violating the Quality of Service constraints on the throughput, end‐to‐end delay, and jitter, as these parameters represent the critical factors in multimedia applications. We propose an end‐to‐end anonymity design that takes into consideration the constraints of Voice‐over‐IP applications in a hybrid network environment, which involves ad hoc and infrastructure networks. Using clusterheads for communication anonymity to preserve user profile privacy, as well as encryption of the real‐time protocol payload, we prove using analysis and simulations that our model can be easily integrated into currently deployed network infrastructures. Copyright © 2016 John Wiley & Sons, Ltd.