7,241 research outputs found

    A cooperative cellular and broadcast conditional access system for Pay-TV systems

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2009 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.The lack of interoperability between Pay-TV service providers and a horizontally integrated business transaction model have compromised the competition in the Pay-TV market. In addition, the lack of interactivity with customers has resulted in high churn rate and improper security measures have contributed into considerable business loss. These issues are the main cause of high operational costs and subscription fees in the Pay-TV systems. As a result, this paper presents the Mobile Conditional Access System (MICAS) as an end-to-end access control solution for Pay-TV systems. It incorporates the mobile and broadcasting systems and provides a platform whereby service providers can effectively interact with their customers, personalize their services and adopt appropriate security measurements. This would result in the decrease of operating expenses and increase of customers' satisfaction in the system. The paper provides an overview of state-of-the-art conditional access solutions followed by detailed description of design, reference model implementation and analysis of possible MICAS security architectures.Strategy & Technology (S&T) Lt

    Mobile integrated conditional access system

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    This paper presents design of a novel security architecture integrating mobile and broadcasting technologies in the Pay-TV system. The security architecture proposed herein is a state-of-the-art solution to tackle well-known problems challenging current Pay-TV systems including but not limited to interoperability amongst service providers, relatively high cost of the service deployment, the security compromise, limited interactivity and bespoken services offered to subscribers. It also proposes the Follow-me service that enables subscribers to access their entitlements via an arbitrary set-top box

    MODELLING LONG-TERM COMMODITIES: THE DEVELOPMENT OF A SIMULATION MODEL FOR THE SOUTH AFRICAN WINE INDUSTRY WITHIN A PARTIAL EQUILIBRIUM FRAMEWORK

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    Econometric demand and supply models of agricultural commodities and crops have been around for a long time with extensive research and adaptations being made in the grain and livestock sectors. This much attention has, however, not been afforded to long term commodities. This paper presents a partial equilibrium framework for modelling long term commodities using the South African wine industry as an example. The model structure and important assumptions are presented, after which the usefulness of the model is tested in the form of baseline projections and the analysis of a typical “what if” question. The wine model presented in this paper is housed and maintained in the Bureau for Food and Agricultural Policy (BFAP) at the Department of Agriculture, Western Cape and the Universities of Pretoria and Stellenbosch.wine market, South Africa, partial equilibrium model, Crop Production/Industries, Demand and Price Analysis,

    An experimental investigation of the structural dynamics of a torsionally soft rotor in vacuum

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    An extensive data base of structural dynamic characteristics has been generated from an experimental program conducted on a torsionally soft two-bladed model helicopter rotor system. Measurements of vibratory strains for five modes of vibration were made at twenty-one locations on the two blades at speeds varying from 0 to 1000 RPM and for several combinations of precone, droop and flexure stiffness. Tests were conducted in vacuum under carefully controlled conditions using a unique excitation device with a system of piezoelectric crystals bonded to the blade surface near the root. Frequencies, strain mode shapes and dampings are extracted from the time histories and can be used to validate structural dynamics codes. The dynamics of the system are such that there is a clear tendency for the first torsion and second flap modes to couple within the speed range considered. Strain mode shapes vary significantly with speed and configuration. This feature is important in the calcualtion of aeroelastic instabilities. The tension axis tests confirmed that the modulus-weighted centroid for the nonhomogeneous airfoil is slightly off the mass centroid and validated previous static tests done to determine location of the tension axis

    Use of a microcomputer database system in a statewide effort for data collection in medical genetics

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    pre-printThe Genetics Office Automation System (GOAS) is a database management system for the collection and reporting of medical genetics data. We have previously reported on its implementation in a single university center [1,2]. We report here on its implementation in a coordinated data collection effort for the State of Missouri. We discuss the current status of the data collection activities and procedures to share data collected at an individual center with state, regional, and national data collection efforts

    Household food insecurity positively associated with increased hospital charges for infants

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    Objective: To test whether household food insecurity (HFI) was associated with total annual hospitalization charges, annual days hospitalized, and charges per day, among low-income infants (months) with any non-neonatal hospital stays. Methods: Administrative inpatient hospital charge data were matched to survey data from infants\u27 caregivers interviewed 1998-2005 in emergency departments in Boston and Little Rock. All study infants had been hospitalized at least once since birth; infants whose diagnoses were not plausibly related to nutrition were excluded from both groups. Log-transformed hospitalization charges were analyzed, controlling for site fixed effects. Results: 24% of infants from food-insecure households and 16% from food-secure households were hospitalized \u3e2 times (P=0.02). Mean annual inpatient hospital charges (6,707vs6,707 vs 5,735; P Conclusion: HFI was positively associated with annual inpatient charges among hospitalized low income infants. Average annual inpatient charges were almost $2,000 higher (inflation adjusted) for infants living in food-insecure households. Reducing or eliminating food insecurity could reduce health services utilization and expenditures for infants in low-income families, most of whom are covered by public health insurance

    Our Solar Siblings: A high school focused robotic telescope-based astronomy education project

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    In this paper, a robotic telescope-centric high-school level astronomy education project, Our Solar Siblings (OSS) is outlined. The project, an LCO official education partner, was formed as an institution-independent non-profit collaboration of volunteers officially in 2014, although the first version of the curriculum materials and approach was initially first designed in 2010. We outline the five goals of the project and the three approaches (formal classroom, independent student research and providing support to similar endeavours) we implement to try and achieve these goals. The curriculum materials, a central part of the project, are outlined as are their connections to various curriculum. The independent research project aspect and recent activity is presented. The article concludes with a brief update on the OSS evaluation which drives the educational design and the project’s future directions as of 2017

    Securing Bring-Your-Own-Device (BYOD) programming exams

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    Traditional pen and paper exams are inadequate for modern university programming courses as they are misaligned with pedagogies and learning objectives that target practical coding ability. Unfortunately, many institutions lack the resources or space to be able to run assessments in dedicated computer labs. This has motivated the development of bring-your-own-device (BYOD) exam formats, allowing students to program in a similar environment to how they learnt, but presenting instructors with significant additional challenges in preventing plagiarism and cheating. In this paper, we describe a BYOD exam solution based on lockdown browsers, software which temporarily turns students' laptops into secure workstations with limited system or internet access. We combine the use of this technology with a learning management system and cloud-based programming tool to facilitate conceptual and practical programming questions that can be tackled in an interactive but controlled environment. We reflect on our experience of implementing this solution for a major undergraduate programming course, highlighting our principal lesson that policies and support mechanisms are as important to consider as the technology itself.Comment: Accepted by SIGCSE 202

    Radiometry for Nighttime Sub-Cloud Imaging of Venus' Surface in the Near-InfraRed Spectrum

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    Does radiometry (e.g., signal-to-noise ratio) limit the performance of near-IR subcloud imaging of our sister planet's surface at night? It does not. We compute subcloud radiometry using above-cloud observations, an assumed ground temperature, sub-cloud absorption and emission modeling, and Rayleigh scattering simulations. We thus confirm both archival and recent studies that deployment of a modest subcloud camera does enable high-resolution surface imaging.Comment: 14 pages, 8 figure
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