39 research outputs found

    A Systems Engineering Methodology for Wide Area Network Selection using an Analytical Hierarchy Process

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    In this paper, we apply a systems engineering methodology to select the most appropriate wide area network (WAN) media suite, according to organizational technical requirements, using an Analytic Hierarchy Process (AHP). AHP is a mathematical decision modeling tool that utilizes decomposition, determination, and synthesis to solve complex engineering decision problems. AHP can deal with the universal modeling of process engineering decision-making, which is difficult to describe quantitatively, by integrating quantitative and qualitative analysis. We formulate and apply AHP to a hypothetical case study in order to examine its feasibility for the WAN media selection problem. The results indicate that our model can improve the decision-making process by evaluating and comparing all alternative WANs. This shows that AHP can support and assist an organization in choosing the most effective solution according to its demands. AHP is an effective resource-saver from many perspectives—it gives high performance, economic, and high quality solutions. Keywords: Analytical Hierarchy Process, Wide Area Network, AHP Consistency, WAN alternatives

    Evaluating and Testing User Interfaces for E-Learning System: Blackboard Usability Testing

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    E-learning usability studies require the involvement of real end-users. Different users with varying background of Human Computer Interaction (HCI) knowledge behave differently when using any e-learning tools. To study user behaviour in the e-learning context, an empirical usability study on a specific e-learning tool is conducted. The study is performed by using usability evaluation questionnaires collected from two different groups of real users of the tool; one group with HCI knowledge and the other without HCI knowledge. It is found that end users without HCI knowledge are more satisfied than the end-users with HCI knowledge, as they have more expectations concerning the tool. Categories and Subject Descriptors: H.5.2 [Information Interfaces and Presentation (e.g., HCI)]: User Interfaces-User-centered design, Evaluation/methodology; H 5.3 [Information Interfaces and Presentation (e.g., HCI)]: Group and Organization Interfaces-Evaluation/methodology, Web-based interaction; K.3.1 [Computers and Education]: Computer Uses in Education-Collaborative learning Keywords: E-learning usability heuristics, Blackboard, e-learning tool, Usability evaluation, HCI

    Evaluating and Improving the Depth Accuracy of Kinect for Windows v2

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    Microsoft Kinect sensor has been widely used in many applications since the launch of its first version. Recently, Microsoft released a new version of Kinect sensor with improved hardware. However, the accuracy assessment of the sensor remains to be answered. In this paper, we measure the depth accuracy of the newly released Kinect v2 depth sensor, and obtain a cone model to illustrate its accuracy distribution. We then evaluate the variance of the captured depth values by depth entropy. In addition, we propose a trilateration method to improve the depth accuracy with multiple Kinects simultaneously. The experimental results are provided to ascertain the proposed model and method

    Pokemon GO in Melbourne CBD: A case study of the cyber-physical symbiotic social networks

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    [EN] The recent popular game, Pokemon GO, created two symbiotic social networks by location-based mobile augmented reality (LMAR) technique. One is in the physical world among players, and another one is in the cyber world among players' avatars. To date, there is no study that has explored the formation of each social network and their symbiosis. In this paper, we carried out a data-driven research on the Pokemon GO game to solve this problem. We accordingly organised the collection of two real datasets. For the first dataset, we designed a questionnaire to collect players' individual behaviours in Pokemon GO, and used maps of Melbourne (Australia) to track and record their usual playing areas. Based on the data that we collected, we modelled the formation of the symbiotic social networks in both physical world (i.e. for players) and cyber world (i.e. for avatars) as well as interactions between players and Pokemon GO elements (i.e. 'bridges' of the two worlds). By investigating the mechanism of network formation, we revealed the relatively weak correlation between the formation processes of the two networks. We further incorporated the real-world pedestrian dataset collected by sensors across Melbourne CBD into the study of their symbiosis. Based on the second dataset, we examined the changes of people's social behaviours in terms of most visited places. The results suggested that the existence of the cyber social network has reciprocally changed the structure of the symbiotic physical social network. (C) 2017 Elsevier B.V. All rights reserved.This research is partially supported by the Australian Research Council projects DP150103732, DP140103649, and LP140100816. The authors extend their appreciation to the International Scientific Partnership Program (ISPP) at King Saud University, Riyadh, Saudi Arabia for funding this work through the project No. ISPP#0069.Wang, D.; Wu, T.; Wen, S.; Liu, D.; Xiang, Y.; Zhou, W.; Hassan Mohamed, H.... (2018). Pokemon GO in Melbourne CBD: A case study of the cyber-physical symbiotic social networks. Journal of Computational Science. 26:456-467. https://doi.org/10.1016/j.jocs.2017.06.009S4564672

    A Hybrid Feature Extraction Method With Regularized Extreme Learning Machine for Brain Tumor Classification

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    Brain cancer classification is an important step that depends on the physician's knowledge and experience. An automated tumor classification system is very essential to support radiologists and physicians to identify brain tumors. However, the accuracy of current systems needs to be improved for suitable treatments. In this paper, we propose a hybrid feature extraction method with a regularized extreme learning machine (RELM) for developing an accurate brain tumor classification approach. The approach starts by preprocessing the brain images by using a min–max normalization rule to enhance the contrast of brain edges and regions. Then, the brain tumor features are extracted based on a hybrid method of feature extraction. Finally, a RELM is used for classifying the type of brain tumor. To evaluate and compare the proposed approach, a set of experiments is conducted on a new public dataset of brain images. The experimental results proved that the approach is more effective compared with the existing state-of-the-art approaches, and the performance in terms of classification accuracy improved from 91.51% to 94.233% for the experiment of the random holdout technique

    Target coverage through distributed clustering in directional sensor networks

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    Maximum target coverage with minimum number of sensor nodes, known as an MCMS problem, is an important problem in directional sensor networks (DSNs). For guaranteed coverage and event reporting, the underlying mechanism must ensure that all targets are covered by the sensors and the resulting network is connected. Existing solutions allow individual sensor nodes to determine the sensing direction for maximum target coverage which produces sensing coverage redundancy and much overhead. Gathering nodes into clusters might provide a better solution to this problem. In this paper, we have designed distributed clustering and target coverage algorithms to address the problem in an energy-efficient way. To the best of our knowledge, this is the first work that exploits cluster heads to determine the active sensing nodes and their directions for solving target coverage problems in DSNs. Our extensive simulation study shows that our system outperforms a number of state-of-the-art approaches
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