7,188 research outputs found
Development of model for insurance risk management and its application to insurance companies operating in the Serbian market
The literature on the topic of risk management in insurance generally separately treat insurance risk and insurance company risk, however such a separate treatment of risk excludes a third type of risk which is defined here, that is the risk of incorrectly calculating insurance risk, which causes uncertainties and disruptions in the operations of an insurance company and its concept of risk management arising from its activities. This paper presents a Model developed for insurance risk management and its attempt to assess the calculation of insurance risk. Also, the Model has been applied to the 2005 to 2010 results of five insurance companies in the Serbian market.Risk; Insurance; Management
A multicarrier amplifier design linearized trough second harmonics and second-order IM feedback
A novel linearisation technique for reduction in the
first and second kind of the third-order intermodulation
products was applied in this paper. The second harmonics and
second-order intermodulation products are led from the output to the input of a power amplifier through a feedback loop. The power amplifier including the feedback loop components (bandpass filter, phase shifter and attenuator) was designed as a hybrid microwave integrated circuit by using program ADS. The phase and amplitude of the loop signals are the adjustable parameters. Therefore, a voltage that controls a phase shift of the phase shifter and a control current of a PIN diode in the attenuator circuit were optimised to obtain a reduction in the third-order intermodulation distortion. For three fundamental signals at the power amplifier input, the lowest improvement of 13 dB for the first and 18 dB for the second kind of the third order intermodulation product levels was achieved
Development and validation of the ACE tool: Assessing medical trainees' competency in evidence based medicine
BACKGROUND: While a variety of instruments have been developed to assess knowledge and skills in evidence based medicine (EBM), few assess all aspects of EBM - including knowledge, skills attitudes and behaviour - or have been psychometrically evaluated. The aim of this study was to develop and validate an instrument that evaluates medical trainees’ competency in EBM across knowledge, skills and attitude. METHODS: The ‘Assessing Competency in EBM’ (ACE) tool was developed by the authors, with content and face validity assessed by expert opinion. A cross-sectional sample of 342 medical trainees representing ‘novice’, ‘intermediate’ and ‘advanced’ EBM trainees were recruited to complete the ACE tool. Construct validity, item difficulty, internal reliability and item discrimination were analysed. RESULTS: We recruited 98 EBM-novice, 108 EBM-intermediate and 136 EBM-advanced participants. A statistically significant difference in the total ACE score was observed and corresponded to the level of training: on a 0-15-point test, the mean ACE scores were 8.6 for EBM-novice; 9.5 for EBM-intermediate; and 10.4 for EBM-advanced (p < 0.0001). Individual item discrimination was excellent (Item Discrimination Index ranging from 0.37 to 0.84), with internal reliability consistent across all but three items (Item Total Correlations were all positive ranging from 0.14 to 0.20). CONCLUSION: The 15-item ACE tool is a reliable and valid instrument to assess medical trainees’ competency in EBM. The ACE tool provides a novel assessment that measures user performance across the four main steps of EBM. To provide a complete suite of instruments to assess EBM competency across various patient scenarios, future refinement of the ACE instrument should include further scenarios across harm, diagnosis and prognosis
Transmission pricing of distributed multilateral energy transactions to ensure system security and guide economic dispatch
In this paper we provide a simulations-based demonstration of a hybrid electricity market that combines the distributed competitive advantages of decentralized markets with the system security guarantees of centralized markets. In this market, the transmission service provider (TSP) guides an electricity market towards the optimal power flow (OPF) solution, even when maximizing its own revenue. End users negotiate with each other to determine an energy price and then submit separate bids for transmission to the TSP. The TSP returns with prices for transmission, allowing end users to respond. In simulations, this hybrid-decentralized market approaches the near-optimal results of fully coordinated and constrained markets. Additionally, this market exhibits properties that remove incentives for the TSP to withhold capacity. This hybrid market leads a market towards the optimum while allowing the TSP and the end users to act out of self-interest. Index Terms₇Electricity markets, transmission, optimum power flow.Supported by the MIT Center for Energy and Environmental Policy Research
Linearization of multichannel amplifiers with the injection of second harmonics into the amplifier and predistortion circuit
A linearization technique that uses the injection of the fundamental signal second harmonics together with the fundamental signals at the amplifier input has been extended in this paper by introducing the injection the second harmonics into nonlinear microwave amplifier and so-called predistortion circuit. Predistortion circuit produces the third-order intermodulation signals that are injected at the amplifier input together with the second harmonics making the linearization procedure more independent on the phase variation of the second harmonics. In addition, a considerably better improvement is attained for the power of fundamental signals close to 1-dB compression point by applying the linearization technique proposed in this paper in comparison to the linearization with the injection of the second harmonics merely in the nonlinear amplifier
The flux ratio of the [OIII] 5007,4959 lines in AGN: Comparison with theoretical calculations
By taking into account relativistic corrections to the magnetic dipole
operator, the theoretical [OIII] 5006.843/4958.511 line intensity ratio of 2.98
is obtained. In order to check this new value using AGN spectra we present the
measurements of the flux ratio of the [OIII] 4959,5007 emission lines for a
sample of 62 AGN, obtained from the Sloan Digital Sky Survey (SDSS) Database
and from published observations. We select only high signal-to-noise ratio
spectra for which the line shapes of the [OIII] 4959,5007 lines are the same.
We obtained an averaged flux ratio of 2.993 +/- 0.014, which is in a good
agreement with the theoretical one.Comment: Accepted for publication in the MNRA
Frequency-selective near-field enhancement of radiative heat transfer via photonic-crystal slabs: a general computational approach for arbitrary geometries and materials
We demonstrate the possibility of achieving enhanced frequency-selective
near-field radiative heat transfer between patterned (photonic crystal) slabs
at designable frequencies and separations, exploiting a general numerical
approach for computing heat transfer in arbitrary geometries and materials
based on the finite-difference time-domain method. Our simulations reveal a
tradeoff between selectivity and near-field enhancement as the slab--slab
separation decreases, with the patterned heat transfer eventually reducing to
the unpatterned result multiplied by a fill factor (described by a standard
proximity approximation). We also find that heat transfer can be further
enhanced at selective frequencies when the slabs are brought into a
glide-symmetric configuration, a consequence of the degeneracies associated
with the non-symmorphic symmetry group
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