57 research outputs found

    JeroMF: A Software Development Framework for Building Distributed Applications Based on Microservices and JeroMQ

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    This report describes a project involving the design, implementation, and testing of a software development framework, called JeroMF, that can help developers create scalable distributed applications based on a microservice architecture and that uses JeroMQ (a native Java implementation of ZeroMQ) for message passing. JeroMF provides an execution framework and extensible components for implementing processes, services, communication channels, messages, communication statistics, and encryption. Applications built with JeroMF do not require a message broker or any other middleware processes. However, they may include an optional Service Registry that can facilitate for service discovery and secure communications. The Service Registry itself was implemented with JeroMF and is included as part of the JeroMF distribution. Thorough unit, integration and system test cases exist for every component of JeroMF. For validation, JeroMF was used to re-design and re-implement a distributed health-care application with 13 separate types of services and very strict security requirements

    Elderly Fall Detection Systems: A Literature Survey

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    Falling is among the most damaging event elderly people may experience. With the ever-growing aging population, there is an urgent need for the development of fall detection systems. Thanks to the rapid development of sensor networks and the Internet of Things (IoT), human-computer interaction using sensor fusion has been regarded as an effective method to address the problem of fall detection. In this paper, we provide a literature survey of work conducted on elderly fall detection using sensor networks and IoT. Although there are various existing studies which focus on the fall detection with individual sensors, such as wearable ones and depth cameras, the performance of these systems are still not satisfying as they suffer mostly from high false alarms. Literature shows that fusing the signals of different sensors could result in higher accuracy and lower false alarms, while improving the robustness of such systems. We approach this survey from different perspectives, including data collection, data transmission, sensor fusion, data analysis, security, and privacy. We also review the benchmark data sets available that have been used to quantify the performance of the proposed methods. The survey is meant to provide researchers in the field of elderly fall detection using sensor networks with a summary of progress achieved up to date and to identify areas where further effort would be beneficial

    Quality of Service in Distributed Stream Processing for large scale Smart Pervasive Environments

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    The wide diffusion of cheap, small, and portable sensors integrated in an unprecedented large variety of devices and the availability of almost ubiquitous Internet connectivity make it possible to collect an unprecedented amount of real time information about the environment we live in. These data streams, if properly and timely analyzed, can be exploited to build new intelligent and pervasive services that have the potential of improving people's quality of life in a variety of cross concerning domains such as entertainment, health-care, or energy management. The large heterogeneity of application domains, however, calls for a middleware-level infrastructure that can effectively support their different quality requirements. In this thesis we study the challenges related to the provisioning of differentiated quality-of-service (QoS) during the processing of data streams produced in pervasive environments. We analyze the trade-offs between guaranteed quality, cost, and scalability in streams distribution and processing by surveying existing state-of-the-art solutions and identifying and exploring their weaknesses. We propose an original model for QoS-centric distributed stream processing in data centers and we present Quasit, its prototype implementation offering a scalable and extensible platform that can be used by researchers to implement and validate novel QoS-enforcement mechanisms. To support our study, we also explore an original class of weaker quality guarantees that can reduce costs when application semantics do not require strict quality enforcement. We validate the effectiveness of this idea in a practical use-case scenario that investigates partial fault-tolerance policies in stream processing by performing a large experimental study on the prototype of our novel LAAR dynamic replication technique. Our modeling, prototyping, and experimental work demonstrates that, by providing data distribution and processing middleware with application-level knowledge of the different quality requirements associated to different pervasive data flows, it is possible to improve system scalability while reducing costs

    An Exploration of Virtual Multi-Family Groups in Schools during a Pandemic – Physically Distanced but Emotionally Close?

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    A body of evidence attests to the link between parenting styles and children’s emotional, cognitive and social outcomes. Consequently, many parenting interventions have developed utilising both behavioural and relational frameworks to support family functioning. One therapeutic, evidence-based approach, Multi-Family Groups (MFG) in schools, seeks to enable families to work with and alongside other families who have similar experiences to reduce social stigma, further social collaboration and equip parents and schools with new resources to tackle individual, specific problems. Social disruption caused by the Coronavirus outbreak has been found to cause cumulative stressors for families, potentially altering parenting practices and placing children at risk of harsher parenting. Arguably this increases the importance of effective interventions to support family functioning. This study provides a unique opportunity to explore the impact of the MFG model being delivered virtually in three, contrasting school settings as social distancing became mandatory. This case study used semi-structured interviews (n=9) with parents, school partners and educational psychologists, triangulated with the researcher’s presence at MFG meetings and supervision sessions. Qualitative data collected was analysed using Thematic Analysis which elicited six key themes within the overarching theme of ‘The Pandemic’: ‘connection as a coping mechanism’; ‘processes for change’; ‘challenges with online therapy’; ‘challenges with the structure online’; and ‘the future for online MFGs’. This study found strong therapeutic alliance online, essential for therapeutic approaches to create significant impact and benefits to all stakeholders. Implications of the research for Educational Psychology Service practice is discussed including evolving technology to enable fidelity of implementation

    Evaluation of Storage Systems for Big Data Analytics

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    abstract: Recent trends in big data storage systems show a shift from disk centric models to memory centric models. The primary challenges faced by these systems are speed, scalability, and fault tolerance. It is interesting to investigate the performance of these two models with respect to some big data applications. This thesis studies the performance of Ceph (a disk centric model) and Alluxio (a memory centric model) and evaluates whether a hybrid model provides any performance benefits with respect to big data applications. To this end, an application TechTalk is created that uses Ceph to store data and Alluxio to perform data analytics. The functionalities of the application include offline lecture storage, live recording of classes, content analysis and reference generation. The knowledge base of videos is constructed by analyzing the offline data using machine learning techniques. This training dataset provides knowledge to construct the index of an online stream. The indexed metadata enables the students to search, view and access the relevant content. The performance of the application is benchmarked in different use cases to demonstrate the benefits of the hybrid model.Dissertation/ThesisMasters Thesis Computer Science 201

    A Peer-to-Peer Network Framework Utilising the Public Mobile Telephone Network

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    P2P (Peer-to-Peer) technologies are well established and have now become accepted as a mainstream networking approach. However, the explosion of participating users has not been replicated within the mobile networking domain. Until recently the lack of suitable hardware and wireless network infrastructure to support P2P activities was perceived as contributing to the problem. This has changed with ready availability of handsets having ample processing resources utilising an almost ubiquitous mobile telephone network. Coupled with this has been a proliferation of software applications written for the more capable `smartphone' handsets. P2P systems have not naturally integrated and evolved into the mobile telephone ecosystem in a way that `client-server' operating techniques have. However as the number of clients for a particular mobile application increase, providing the `server side' data storage infrastructure becomes more onerous. P2P systems offer mobile telephone applications a way to circumvent this data storage issue by dispersing it across a network of the participating users handsets. The main goal of this work was to produce a P2P Application Framework that supports developers in creating mobile telephone applications that use distributed storage. Effort was assigned to determining appropriate design requirements for a mobile handset based P2P system. Some of these requirements are related to the limitations of the host hardware, such as power consumption. Others relate to the network upon which the handsets operate, such as connectivity. The thesis reviews current P2P technologies to assess which was viable to form the technology foundations for the framework. The aim was not to re-invent a P2P system design, rather to adopt an existing one for mobile operation. Built upon the foundations of a prototype application, the P2P framework resulting from modifications and enhancements grants access via a simple API (Applications Programmer Interface) to a subset of Nokia `smartphone' devices. Unhindered operation across all mobile telephone networks is possible through a proprietary application implementing NAT (Network Address Translation) traversal techniques. Recognising that handsets operate with limited resources, further optimisation of the P2P framework was also investigated. Energy consumption was a parameter chosen for further examination because of its impact on handset participation time. This work has proven that operating applications in conjunction with a P2P data storage framework, connected via the mobile telephone network, is technically feasible. It also shows that opportunity remains for further research to realise the full potential of this data storage technique

    IEOM Society International

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    IEOM Society Internationa

    Software Maintenance At Commit-Time

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    Software maintenance activities such as debugging and feature enhancement are known to be challenging and costly, which explains an ever growing line of research in software maintenance areas including mining software repository, default prevention, clone detection, and bug reproduction. The main goal is to improve the productivity of software developers as they undertake maintenance tasks. Existing tools, however, operate in an offline fashion, i.e., after the changes to the systems have been made. Studies have shown that software developers tend to be reluctant to use these tools as part of a continuous development process. This is because they require installation and training, hindering their integration with developers’ workflow, which in turn limits their adoption. In this thesis, we propose novel approaches to support software developers at commit-time. As part of the developer’s workflow, a commit marks the end of a given task. We show how commits can be used to catch unwanted modifications to the system, and prevent the introduction of clones and bugs, before these modifications reach the central code repository. We also propose a bug reproduction technique that is based on model checking and crash traces. Furthermore, we propose a new way for classifying bugs based on the location of fixes that can serve as the basis for future research in this field of study. The techniques proposed in this thesis have been tested on over 400 open and closed (industrial) systems, resulting in high levels of precision and recall. They are also scalable and non-intrusive

    European Information Technology Observatory 1998

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