862,737 research outputs found

    Framework for Efficient Electrical Energy Management Practice in Public Universities in Southwestern Nigeria

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    Energy management practices are subject to various worries that impact on achieving electricity saving objectives. This is most apparent in the case of Public Universities in Nigeria due to the number of electricity end users with conflicting interests. Efficient electrical energy management in Public Universities in Nigeria becomes crucial. The present work developed a multidimensional framework of efficient electricity management by considering all relevant measures of performance. To achieve the formation of this evaluation framework, it has considered the case of three relatively old public universities and collected the viewpoints of 4728 respondents comprising students, staff, and business owners involved in the aggregate electricity use in Public Universities in Nigeria. We adopted a quantitative survey and questionnaire as instrument for gathering relevant data. The results of the analysis of data obtained during the survey were used to develop the framework by considering key attributes. The study concluded that the formation of the newly-proposed quantitative efficient electricity management framework for improving the energy performance of public university buildings can provide the university management with an effective tool to benchmark with different university buildings internationally and assist the priority setting of efficient electricity savings. Keywords: Framework, Efficiency, electrical energy management, Practice, Public universities, Southwestern Nigeri

    Design and analysis of group key exchange protocols

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    A group key exchange (GKE) protocol allows a set of parties to agree upon a common secret session key over a public network. In this thesis, we focus on designing efficient GKE protocols using public key techniques and appropriately revising security models for GKE protocols. For the purpose of modelling and analysing the security of GKE protocols we apply the widely accepted computational complexity approach. The contributions of the thesis to the area of GKE protocols are manifold. We propose the first GKE protocol that requires only one round of communication and is proven secure in the standard model. Our protocol is generically constructed from a key encapsulation mechanism (KEM). We also suggest an efficient KEM from the literature, which satisfies the underlying security notion, to instantiate the generic protocol. We then concentrate on enhancing the security of one-round GKE protocols. A new model of security for forward secure GKE protocols is introduced and a generic one-round GKE protocol with forward security is then presented. The security of this protocol is also proven in the standard model. We also propose an efficient forward secure encryption scheme that can be used to instantiate the generic GKE protocol. Our next contributions are to the security models of GKE protocols. We observe that the analysis of GKE protocols has not been as extensive as that of two-party key exchange protocols. Particularly, the security attribute of key compromise impersonation (KCI) resilience has so far been ignored for GKE protocols. We model the security of GKE protocols addressing KCI attacks by both outsider and insider adversaries. We then show that a few existing protocols are not secure against KCI attacks. A new proof of security for an existing GKE protocol is given under the revised model assuming random oracles. Subsequently, we treat the security of GKE protocols in the universal composability (UC) framework. We present a new UC ideal functionality for GKE protocols capturing the security attribute of contributiveness. An existing protocol with minor revisions is then shown to realize our functionality in the random oracle model. Finally, we explore the possibility of constructing GKE protocols in the attribute-based setting. We introduce the concept of attribute-based group key exchange (AB-GKE). A security model for AB-GKE and a one-round AB-GKE protocol satisfying our security notion are presented. The protocol is generically constructed from a new cryptographic primitive called encapsulation policy attribute-based KEM (EP-AB-KEM), which we introduce in this thesis. We also present a new EP-AB-KEM with a proof of security assuming generic groups and random oracles. The EP-AB-KEM can be used to instantiate our generic AB-GKE protocol

    "On Fiscal Federalism under Democracy"

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    In his seminal work on fiscal federalism, Oates (1972) addressed the socalled Decentralization Theorem, which states that, if such factors as scale economies and spillovers are left out of consideration, a decentralized system is always more efficient than a centralized system for the supply of local public goods. Based on his analytical framework, we contrarily show that a centralized system is at times more efficient than a decentralized system under a democratic decision rule (Proposition 2). The key to such a possibility is the interests of minorities that may be sacrificed in each lower district under decentralization. That is, when the majority adopts an extreme policy that is far from minorities' tastes in a lower district under decentralization, if instead a moderate policy which is closer to minorities' tastes were chosen under centralization, then the interests of minorities would be saved. As a result, centralization could attain higher social welfare than decentralization.

    An authentication framework for Wireless Sensor Networks using identity-based signatures

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    In Wireless Sensor Networks (WSNs), authentication is a crucial security requirement to avoid attacks against secure communication, and to mitigate DoS attacks exploiting the limited resources of sensor nodes. Resource constraints of sensor nodes are hurdles in applying strong public key cryptographic based mechanisms in WSNs. To address the problem of authentication in WSNs, we propose an efficient and secure framework for authenticated broadcast/multicast by sensor nodes as well as for outside user authentication, which utilizes identity based cryptography and online/offline signature schemes. The primary goals of this framework are to enable all sensor nodes in the network, firstly, to broadcast and/or multicast an authenticated message quickly; secondly, to verify the broadcast/multicast message sender and the message contents; and finally, to verify the legitimacy of an outside user. The proposed framework is also evaluated using the most efficient and secure identity-based signature schemes

    Challenges for health care development in Croatia [Izazovi razvoja zdravstvenog sustava Republike Hrvatske]

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    The main aim of the research done in this paper was to establish key challenges and perspectives for health care development in the Republic of Croatia in the next two decades. Empirical research was conducted in the form of semi-structured interviews involving 49 subjects, representatives of health care professionals from both, public and private sectors, health insurance companies, pharmaceutical companies, drug wholesalers, and non-governmental organisations (patient associations). The results have shown that key challenges and problems of Croatian health care can be divided into three groups: functioning of health care systems, health care personnel, and external factors. Research has shown that key challenges related to the functioning of health care are inefficiency, financial unviability, inadequate infrastructure, and the lack of system transparency. Poor governance is another limiting factor. With regard to health care personnel, they face the problems of low salaries, which then lead to migration challenges and a potential shortage of health care personnel. The following external factors are deemed to be among the most significant challenges: ageing population, bad living habits, and an increase in the number of chronic diseases. However, problems caused by the global financial crisis and consequential macroeconomic situation must not be neglected. Guidelines for responding to challenges identified in this research are the backbone for developing a strategy for health care development in the Republic of Croatia. Long-term vision, strategy, policies, and a regulatory framework are all necessary preconditions for an efficient health care system and more quality health services

    Public involvement in health research: a case study of one NHS project over 5 years

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    Background: Public involvement, both in the National Health Service (NHS) and in clinical research, is promoted as an important democratic principle. The declared aims are to reduce professional autocracy and allow a broader ownership of the research agenda; also to improve the design of, and recruitment and retention of patients to, clinical studies. There have been a number of national initiatives in the UK to improve public input to clinical research activities, but very few reports of effective and sustainable partnerships over time. This study reports the evaluation of one example, which is embedded in the NHS and university partnerships in the Norfolk area of England. Objectives Evaluate: • Putting principles into practice of public involvement in research over a 5 year period for one specific project (Patient and Public Involvement in Research). • How the model contributes to, and impacts upon, all stages of the research process. • Attitudes of the research community and lay volunteers to their mutual experiences of public involvement. • Key factors and strengths of this project, and areas for improvement. Methods: A mixed methods approach related to the 5 years from start of 2003 to end of 2007. This used descriptive statistics of volunteer activity, interviews with key stakeholders (13), questionnaires (53% response rate), and focus group with 10 volunteers to explore emergent themes. We analysed findings using a policy framework approach. Results: About 47 of the original 55 volunteers remained on the panel after 5 years. All have undertaken training, 38% have been involved in the full range of research activities offered, and 75% have attended at least one research project meeting. Some are active in governance, ethics, and advisory committees. Both the research community and the volunteers are very positive about the project. The researchers find it provides well prepared personnel, and gives a speedy and efficient way of fulfilling the expectations of funders for lay input. The volunteers find it gives them important opportunities to influence the quality of research and thus support improvements in patient care. Areas for improvement include increasing social diversity among the volunteers, and improving feedback on input from volunteers, without which volunteers tend to lose confidence and motivation. Conclusion: Long-term sustainable and valuable public input to research is possible. Key factors are committing resources, embedding the service in the infrastructure of a research consortium, and ongoing responsiveness by NHS staff and researchers. Additional activity to recruit and support access may be needed to attract people from a broad range of sociodemographic backgrounds. Some volunteers want more involvement than this model currently offers
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