1,721,028 research outputs found
Design Workstation of the Future
No full textDesign research must be concerned with providing industry with significant competitive advantages in product and process design by developing advanced design methods and computer-based design tools, techniques, systems ad applications that support the creation of reliable, high quality, cost-effective, innovation and competitive products. The Design Technology Research Centre (DTRC) in the School of Design at the Hong Kong Polytechnic University focuses on the development of computer enhanced design processes and product-orientated and user-centred design tools and systems. Evolutionary computation, generative and knowledge based systems, Artificial Intelligence, integrated and interactive system techniques, virtual reality and computer supported collaborative work are employed for the implementation of these processes, tools and systems. In this paper, the author presents an overview of the research undertaken by the DTRC and discusses the issues related to the development of the design workstation of the future
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mobility management and mobile server dispatching in fixed-to-mobile and mobile-to-mobile edge computing
Get PDFMobile edge computing (MEC) has been considered as a promising technology to handle computation-intensive and latency-sensitive tasks for mobile user equipments (UEs) in next-generation mobile networks. Mobile UEs can offload these tasks to nearby edge servers, which are typically deployed on base stations (BSs) that are equipped with computation resources. Thus, the task execution latency as well as the energy consumption of mobile devices can be reduced.
Mobility management has played a fundamental role in MEC, which associates UEs with the appropriate BSs. In the existing handover decision-making process, the communication costs dominate. However, in edge scenario, the computation capacity constraints should also be considered. Due to user mobility, mobile UEs are nonuniformly distributed over time and space. Edge servers in hot-spot areas can be overloaded while others are underloaded. When edge servers are densely deployed, each UE may have multiple choices to offload its tasks. Instead, if edge servers are sparsely deployed, UEs may only have one option for task offloading. This aggravates the unbalanced workload of the deployed edge servers. Therefore, how to serve the dynamic hot-spot areas needs to be addressed in different edge server deployment scenarios.
Considering these two scenarios discussed above, two problems are addressed in this thesis: 1) with densely deployed edge servers, for each mobile UE, how to choose the appropriate edge servers independently without full system information is inves- tigated, and 2) with sparsely deployed edge servers, how to serve dynamic hot-spot areas in an efficient and flexible way is emphasized. First, with BSs densely de- ployed in hot-spot areas, mobile UEs can offload their tasks to one of the available edge servers nearby. However, precise full system information such as the server workload can be hard to be synchronized in real time, which also introduces extra signaling overhead for mobility management decision-making. Thus, a user-centric reinforcement-learning-based mobility management scheme is proposed to handle sys- tem uncertainties. Each UE observes the task latency and automatically learns the optimal mobility management strategy through trial and feedback. Simulation results show that the proposed scheme manifests superiority in dealing with system uncer- tainties. When compared with the traditional received signal strength (RSS)-based handover scheme, the proposed scheme reduces the task execution latency by about 30%.
Second, fixed edge servers that are sparsely deployed around mobile UEs are not flexible enough to deal with time-varying task offloading. Dispatching mobile servers is formulated as a variable-sized bin-packing problem with geographic constraints. A novel online unmanned aerial vehicle (UAV)-mounted edge server dispatching scheme is proposed to provide flexible mobile-to-mobile edge computing services. UAVs are dispatched to the appropriate hover locations by identifying the hot-spot areas sequen- tially. Theoretical analysis is provided with the worst-case performance guarantee. Extensive evaluations driven by real-world mobile requests show that, with a given task finish time, the mobile dispatching scheme can serve 59% more users on aver- age when compared with the fixed deployment. In addition, the server utilization reaches 98% during the daytime with intensive task requests. Utilizing both the fixed and mobile edge servers can satisfy even more UE demands with fewer UAVs to be dispatched and a better server utilization.
To sum up, not only the communication condition but also the computation lim- itation have an impact on the edge server selection and mobility management in MEC. Moreover, dispatching mobile edge servers can be an effective and flexible way to supplement the fixed servers and deal with dynamic offloading requests.Graduat
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Complex Form Visualization and Geometric Design
No full textEvolution and visualization of primitive as well as complex forms in a computer based enhanced design process is essential for designers to create and evaluate the concepts and 3D forms being generated. The issue is more complicated in a virtual environment where a full immersive and interactive effect is to be expected. This paper aims at developing a taxonomy of 3D complex geometric forms that can be visualised and evolved. Components of surfaces based on the taxonomy will be built for creative shape design. Demonstrations will be developed to show the theory and virtual applications
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Edge server placement considering resilience in mobile edge computing networks
Get PDFIn today’s rapidly evolving communication landscape, the demand for exceptional Quality of Service (QoS) and Quality of Experience (QoE) in communication networks has reached unprecedented levels. This surge in demand can be attributed to the explosive growth and pervasive deployment of Internet infrastructure. Emerging technologies and novel applications underscore the urgency for a network architecture that not only delivers speed and efficiency but also boasts scalability and resilience beyond the capabilities of traditional cloud computing networks. Mobile Edge Computing (MEC) stands as a promising solution to address these challenges. By deploying Edge Servers (ESs) in close proximity to end-user devices, MEC enables the offloading of delay-sensitive and computationally intensive workloads from mobile applications. This deployment, in turn, mitigates latency issues and enhances the QoE for mobile users. However, the reliability of Edge Server Placement (ESP) within MEC networks is of paramount importance. While several studies have explored the ESP problem in MEC networks, they often focus on two main objectives: minimizing Edge Server (ES) access delay and optimizing workload distribution. However, one critical aspect has been relatively under-emphasized: the resiliency of ESP. The failure or malfunction of ESs, stemming from various challenges, can disrupt operations and degrade the overall QoS/QoE of the network. In this study, we tackle the ESP problem in MEC networks from a distinctive perspective. Our focal point is to minimize ES access delay, efficiently balance workloads, and significantly enhance network resilience. To achieve these objectives, our innovative algorithm employs a dual strategy. First, we utilize the robust K-medoids clustering algorithm for ESP, optimizing the architectural layout of MEC networks. Second, we introduce a bespoke heuristic algorithm designed to allocate multiple ESs to each Base Station (BS), thereby fortifying network resilience. This approach not only adheres to various constraints but also ensures uninterrupted services, even in the face of server failures, while consistently meeting key performance indicators. Experimental results, based on real-world data, prove the effectiveness of our algorithm. It not only reduces access delay and workload imbalances but also ensures responsive performance and uninterrupted services, even in scenarios involving ES failures.Graduat
Opportunistic routing in intermittently connected wireless mobile social networks
Get PDFConsumer electronics such as cellular phones and portable computers with short-range communication capabilities have enabled the large-scale information dissemination through user mobility and contact, without the assistance of communication infrastructures. In such a new communication paradigm, one challenge is to determine when and how to forward a message to the destination, possibly through a series of third parties. This problem has attracted a lot of attention in the literature lately, with proposals ranging from epidemic to single or multi-copy spray and wait or focus strategies. However most existing work assumed independent or identically distributed mobility. Observing most human mobility and interaction are interest-driven in the real world, in this research, we evaluate the performance of these schemes with an interest-driven mobility model. We further propose to take the user interest into account when determining routing strategies to further improve the performance of these schemes for mobile social networks. Simulation results have demonstrated the efficacy of the interest-aware routing strategies.Graduat
Malicious Drive-By-Download Website Classification Using JavaScript Features
No full textIn recent years, Drive-by-download attacks make up over 90% of web-based attacks on web users. Many web users fall victim to this type of attacks due to its simplicity and less complex requirements to be compromised. They simply need to click on a malicious URL while having some browser vulnerabilities for the malicious attackers to compromise their machine and to obtain their sensitive information. To combat these attacks, proactive blacklists are used nowadays for preventing web users from accessing these malicious web pages. This report attempts to supplement the existing proactive blacklisting framework by introducing JavaScript feature vectors for classification. These feature vectors include the functionality of JavaScript in terms of JavaScript bytecode, as well as some string analysis properties for the classification of benign and malicious web pages. A few different classifiers are tested and compared to provide insight on the different JavaScript feature vectors defined.Graduat
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