1,461 research outputs found

    Dealing with goal models complexity using topological metrics and algorithms

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    The inherent complexity of business goal-models is a challenge for organizations that has to analyze and maintaining them. Several approaches are developed to reduce the complexity into manageable limits, either by providing support to the modularization or designing metrics to monitor the complexity levels. These approaches are designed to identify an unusual complexity comparing it among models. In the present work, we expose two approaches based on structural characteristics of goal-model, which do not require these comparisons. The first one ranksthe importance of goalsto identify a manageable set of them that can be considered as a priority; the second one modularizes the model to reduce the effort to understand, analyze and maintain the model.Peer ReviewedPostprint (published version

    Formative Evaluation of Job Clubs Operated by Faith- and Community-Based Organizations: Findings From Site Visits and Options for Future Evaluation

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    Over the past several decades, job search support groups, commonly referred to as “job clubs,” have evolved into one of several important activities used by the public workforce system and faith- and community-based organizations to enhance worker readiness and employability, as well as to provide ongoing support to unemployed and underemployed individuals as they search for jobs. The U.S. Department of Labor\u27s (DOL) Chief Evaluation Office (CEO) contracted in September 2012 with Capital Research Corporation, Inc. and George Washington University to conduct an assessment of job clubs sponsored by faith-based and community-based organizations (FBOs/CBOs). The overall purpose of this evaluation effort was to systematically describe the key characteristics of job clubs being offered by a range of faith- and community- based organizations, document how they differ from and are similar to the job clubs operated by publicly-funded workforce agencies (such as at American Job Centers [AJCs]), and identify potential approaches that might be used for more rigorous formal evaluation of impacts and effectiveness. Findings from the telephone interviews with stakeholders and in-person interviews with facilitators during the site visits indicate that job clubs operated by FBOs, CBOs and public workforce agencies are alike in many ways, with all of them emphasizing the critical importance of: (1) networking during the job search; (2) offering ongoing peer support and sharing of similar experiences among participants; and (3) providing instruction and guidance on the basics of the job search process (e.g., elevator pitches, resume development, job interview practice). Noteworthy differences between the FBO/CBO job clubs and those operated by public workforce agencies are related to staffing patterns and available resources for program operations and services. While public workforce agency job clubs are led by paid professional staff, supported by the full complement of workshops, activities, and other services typically available through AJCs/One-Stop Centers, FBO/CBO job clubs, in most cases, operate with limited budgets or no funding whatsoever. Additionally, compared with public sector agencies, FBOs/CBOs typically collect little in the way of participant-level data, such as participant identifiers, demographic characteristics, service receipt, or outcomes. Finally, although this report suggests several approaches to future rigorous experimental/non-experimental and process/implementation evaluation of FBO/CBO-sponsored job clubs, there are likely to be formidable challenges to implementation of rigorous evaluation methods because these job clubs rarely collect identifying information on participants, such as Social Security numbers, and are generally opposed to random assignment for their programs

    Analysis of Solar Energy Aggregation under Various Billing Mechanisms

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    Ongoing reductions in the cost of solar photovoltaic (PV) systems are driving their increased installations by residential households. Various incentive programs such as feed-in tariff, net metering, net purchase and sale that allow the prosumers to sell their generated electricity to the grid are also powering this trend. In this paper, we investigate sharing of PV systems among a community of households, who can also benefit further by pooling their production. Using cooperative game theory, we find conditions under which such sharing decreases their net total cost. We also develop allocation rules such that the joint net electricity consumption cost is allocated to the participants. These cost allocations are based on the cost causation principle. The allocations also satisfy the standalone cost principle and promote PV solar aggregation. We also perform a comparative analytical study on the benefit of sharing under the mechanisms favorable for sharing, namely net metering, and net purchase and sale. The results are illustrated in a case study using real consumption data from a residential community in Austin, Texas.Comment: 12 page

    Inter-organizational fault management: Functional and organizational core aspects of management architectures

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    Outsourcing -- successful, and sometimes painful -- has become one of the hottest topics in IT service management discussions over the past decade. IT services are outsourced to external service provider in order to reduce the effort required for and overhead of delivering these services within the own organization. More recently also IT services providers themselves started to either outsource service parts or to deliver those services in a non-hierarchical cooperation with other providers. Splitting a service into several service parts is a non-trivial task as they have to be implemented, operated, and maintained by different providers. One key aspect of such inter-organizational cooperation is fault management, because it is crucial to locate and solve problems, which reduce the quality of service, quickly and reliably. In this article we present the results of a thorough use case based requirements analysis for an architecture for inter-organizational fault management (ioFMA). Furthermore, a concept of the organizational respective functional model of the ioFMA is given.Comment: International Journal of Computer Networks & Communications (IJCNC

    Phase topology identification in low-voltage distribution networks: a Bayesian approach

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    Knowledge of customer phase connection in low-voltage distribution networks is important for Distribution System Operators (DSOs). This paper presents a novel data-driven phase identification method based on Bayesian inference, which uses load consumption profiles as inputs. This method uses a non-linear function to establish the probability of a customer being connected to a given phase, based on variations in the customer’s consumption and those in the phase feeders. Owing to the Bayesian inference, the proposed method can provide up-to-date certainty about the phase connection of each customer. To improve the detection of those customers that are more difficult to identify, after obtaining the up-to-date certainty for all users, the consumption of those who have an up-to-date certainty above a certain percentile compared with the rest of the substation (those that are more likely to be correctly classified) is subtracted from the phase in which they are classified. The performance of the proposed method was evaluated using a real (non-synthetic) low-voltage distribution network. Favourable results (with accuracies higher than 97 %) were obtained in almost all cases, regardless of the percentage of Smart Meter penetration and the size of the substation. A comparison with other state-of-the-art methods showed that the proposed method outperforms (or equals) them. The proposed method does not necessarily require previously labelled data; however, it can handle them even if they contain errors. Having previous information (partial or complete) increases the performance of phase identification, making it possible to correct erroneous previous labelling

    False Data Injection Attacks in Smart Grids: State of the Art and Way Forward

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    In the recent years cyberattacks to smart grids are becoming more frequent Among the many malicious activities that can be launched against smart grids False Data Injection FDI attacks have raised significant concerns from both academia and industry FDI attacks can affect the internal state estimation processcritical for smart grid monitoring and controlthus being able to bypass conventional Bad Data Detection BDD methods Hence prompt detection and precise localization of FDI attacks is becomming of paramount importance to ensure smart grids security and safety Several papers recently started to study and analyze this topic from different perspectives and address existing challenges Datadriven techniques and mathematical modelings are the major ingredients of the proposed approaches The primary objective of this work is to provide a systematic review and insights into FDI attacks joint detection and localization approaches considering that other surveys mainly concentrated on the detection aspects without detailed coverage of localization aspects For this purpose we select and inspect more than forty major research contributions while conducting a detailed analysis of their methodology and objectives in relation to the FDI attacks detection and localization We provide our key findings of the identified papers according to different criteria such as employed FDI attacks localization techniques utilized evaluation scenarios investigated FDI attack types application scenarios adopted methodologies and the use of additional data Finally we discuss open issues and future research direction

    Integrated monitoring of multi-domain backbone connections -- Operational experience in the LHC optical private network

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    Novel large scale research projects often require cooperation between various different project partners that are spread among the entire world. They do not only need huge computing resources, but also a reliable network to operate on. The Large Hadron Collider (LHC) at CERN is a representative example for such a project. Its experiments result in a vast amount of data, which is interesting for researchers around the world. For transporting the data from CERN to 11 data processing and storage sites, an optical private network (OPN) has been constructed. As the experiment data is highly valuable, LHC defines very high requirements to the underlying network infrastructure. In order to fulfil those requirements, the connections have to be managed and monitored permanently. In this paper, we present the integrated monitoring solution developed for the LHCOPN. We first outline the requirements and show how they are met on the single network layers. After that, we describe, how those single measurements can be combined into an integrated view. We cover design concepts as well as tool implementation highlights.Comment: International Journal of Computer Networks & Communications (IJCNC
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