Joint Power and Time Allocation Scheme with QoS Constraints in Overlay Multi-user Cognitive Radio Networks

This paper studies the case of an overlay cognitive radio network where the primary user leases spectral resources to the secondary user in exchange for cooperation, considering that both type of users have specific quality of service requirements. We investigate the problem of joint power and time allocation for the secondary access during the cooperative phase, with a view to optimizing the effective capacity of the primary user given an average energy constraint for the secondary user. Afterwards, the optimal power allocation of the secondary user for its own transmission phase is investigated in order to maximize the effective capacity of the secondary link. The proposed joint power and time allocation mechanism is compared with an optimal time/constant power allocation scheme and a less sophisticated baseline allocation scheme, i.e. power allocation under constant time and its superiority is proven for various network parameters. The reference model of one primary–one secondary user is extended to a general multi user cognitive radio network through the proposed pairing mechanism based on matching theory. Particularly, considering the remarks of the reference scenario, we propose two different matching schemes (with/without consideration of primary users’ quality of service requirements) and we confirm their superiority compared to other matching mechanisms.     

Scattering from an infinite cylinder of small radius embedded intoa dielectric one

In this paper the scattering from an infinite metallic or dielectric cylinder of electrically small radius, embedded into a dielectric cylinder, is considered. The problem is solved by the method of separation of variables, in conjunction with translational addition theorems. Analytical expressions are obtained for the scattered field and the various scattering cross-sections, when the radius of the inner cylinder is electrically small. Both polarizations are considered for normal incidence. Numerical results are given for various values of the parameters and for metallic or dielectric inner cylinder     

Cutoff frequencies of eccentric circular-elliptic metallicwaveguides

In this paper semianalytical expressions for the cutoff frequencies of eccentric circular-elliptic perfectly conducting waveguides, are derived for both TM and TE modes. Two types of waveguides are considered, one with circular inner and elliptic outer conductor and one with elliptic inner and circular outer conductor. The electromagnetic field is expressed in terms of both circular and elliptical cylindrical wave functions, which are connected with one another by well-known expansion formulas. Translational addition theorems for circular cylindrical wave functions are also used for the satisfaction of the boundary conditions in the outer conductor. When the solutions are specialized to small values of h=kc/2 (c is the interfocal distance of the elliptic conductor and k the cutoff wavenumber) semianalytical expressions of the form [f(h)=f(0)1+gh²+O(h ⁴)] are obtained for the cutoff frequencies of the corresponding waveguide. For several values of the parameters, both waveguides may appear to have larger operational bandwidth as compared to that of the corresponding eccentric circular one. Numerical results for both waveguides and both kinds of modes are given for various values of the parameters     

Observability-based consistent EKF estimators for multi-robot cooperative localization

In this paper, we investigate the consistency of extended Kalman filter (EKF)-based cooperative localization (CL) from the perspective of observability. We analytically show that the error-state system model employed in the standard EKF-based CL always has an observable subspace of higher dimension than that of the actual nonlinear CL system. This results in unjustified reduction of the EKF covariance estimates in directions of the state space where no information is available, and thus leads to inconsistency. To address this problem, we adopt an observability-based methodology for designing consistent estimators in which the linearization points are selected to ensure a linearized system model with observable subspace of correct dimension. In particular, we propose two novel observability-constrained (OC)-EKF estimators that are instances of this paradigm. In the first, termed OC-EKF 1.0, the filter Jacobians are calculated using the prior state estimates as the linearization points. In the second, termed OC-EKF 2.0, the linearization points are selected so as to minimize their expected errors (i.e., the difference between the linearization point and the true state) under the observability constraints. The proposed OC-EKFs have been tested in simulation and experimentally, and have been shown to significantly outperform the standard EKF in terms of both accuracy and consistency.     

A Review of Experimental Investigations into Object-Oriented Technology

In recent years there has been a growing interest in empirically investigating object-oriented technology (OOT). Much of this empirical work has been experimental in nature. This paper reviews the published output of such experiments—18 in total—with the twin aims of, first, assessing what has been learnt about OOT and, second, what has been learnt about conducting experimental work. We note that much work has focused upon evaluation of the inheritance mechanism. Whilst such experiments are of some interest, we observe that this may be of less significance to the OOT community than experimenters seem to believe. Instead, OOT workers place more emphasis upon other mechanisms such as composition, components, frameworks, architectural styles and design patterns. This leads us to conclude that the empirical researchers need to ensure that their work keeps pace with technological developments in the fields they aim to investigate.     

Real-time wireless multisensory smart surveillance with 3D-HEVC streams for internet-of-things (IoT)

This paper presents the design of a novel, real-time, wireless, multisensory, smart surveillance system with 3D-HEVC features. The proposed high-level system architecture of the surveillance system is analyzed. The advantages of HEVC encoding are presented. Methods for synchronization between multiple streams are presented. Available wireless standards are presented and compared. A network-adaptive transmission protocol for a reliable, real-time, multisensory surveillance system is proposed. Adaptive packet frame grouping (APFG) and adaptive quantization are deployed to maximize the quality-of-experience (QoE). Measurements of the proposed protocol have been shown to provide superior results compared to existing transport protocols.     

Electromagnetic scattering by an infinite cylinder of material or metamaterial coating eccentrically a dielectric cylinder

The electromagnetic scattering by an infinite cylinder of dielectric material or metamaterial, coating eccentrically another infinite dielectric cylinder, is treated in this work. The problem is solved using classical separation of variables techniques. No use is made of the translational addition theorem. For small eccentricities h = d/a(? 1), where d is the distance between the axes of the cylinders and a the radius of the outer cylinder, we use instead the cosine and the sine laws to satisfy the boundary conditions at the surface of the outer cylinder. Keeping terms up to the order h2 we finally obtain exact, closed-form expressions for the expansion coefficients g(1) and g(2) in the relation S(h) = S(0)[1 + g(1)h + g(2)h2 + O(h3)], giving the scattered field and the scattering cross sections of the problem, where S(0) corresponds to the coaxial geometry, with h = 0 (d = 0). Both polarizations are considered for normal incidence. Numerical results are given for various values of the parameters, corresponding to materials or metamaterials. Our method is an alternative of the one using the translational addition theorem in the case of small eccentricities h.     

A Degron Blocking Strategy Towards Improved CRL4CRBN Recruiting PROTAC Selectivity**

Small molecules inducing protein degradation are important pharmacological tools to interrogate complex biology and are rapidly translating into clinical agents. However, to fully realise the potential of these molecules, selectivity remains a limiting challenge. Herein, we addressed the issue of selectivity in the design of CRL4^CRBN recruiting PROteolysis TArgeting Chimeras (PROTACs). Thalidomide derivatives used to generate CRL4^CRBN recruiting PROTACs have well described intrinsic monovalent degradation profiles by inducing the recruitment of neo-substrates, such as GSPT1, Ikaros and Aiolos. We leveraged structural insights from known CRL4^CRBN neo-substrates to attenuate and indeed remove this monovalent degradation function in well-known CRL4^CRBN molecular glues degraders, namely CC-885 and Pomalidomide. We then applied these design principles on a previously published BRD9 PROTAC (dBRD9-A) and generated an analogue with improved selectivity profile. Finally, we implemented a computational modelling pipeline to show that our degron blocking design does not impact PROTAC-induced ternary complex formation. We believe that the tools and principles presented in this work will be valuable to support the development of targeted protein degradation.