With both mobile network services and related data traffic volume on the rise, reliability of the radio access network is of the essence. A number of radio functional splits are defined by 3GPP to offer increased flexibility of implementation and feasibility of new mobile network services. For example, it is possible to implement certain radio functions in the Cloud, an architectural solution referred to as C-RAN. C-RAN solutions require highly reliable backhaul and fronthaul network designs. This paper describes PROnet, a programmable optical software-defined network testbed, which has been upgraded to offer backhaul and fronthaul transport capabilities in support of C-RAN functionalities with increased reliability. The testbed is upgraded with a specially designed 1 + 1 protection mechanism at the Ethernet layer in order to meet the stringent network round-trip requirements imposed by one of the C-RAN functional split options on the fronthaul.
Multidimensional Systems and Signal Processing - In the current paper, linear dynamical system identification by relevant and irrelevant multi-sensor observations is presented. In common system... 相似文献
This paper deals with the dynamic modeling and base inertial parameter determination of a general 5R 2-degree-of-freedom spherical parallel manipulator. By using a new geometric approach, inverse and forward kinematic problem are transformed to the problem of determining the intersection of two cones with common vertex. Compared to other proposed methods, this approach yields more compact and closed-form solutions. The instantaneous kinematic and acceleration problem is solved via employing the screw theory. The dynamic model is formulated by means of the principle of virtual work and the concept of link Jacobian matrices. In order to verify the proposed methods and equations, a case study is performed, in which an orthogonal 2-DOF spherical parallel manipulator, named TezGoz, is considered. Performed simulations and comparisons with a SimMechanics model show the correctness of the derived equations. Furthermore, a reduced dynamic model is obtained by determining the base inertial parameters. To do so, first the dynamic model is rewritten in a linear matrix form with respect to the inertial parameters of the mechanism, then parameters are grouped to obtain a set of independent base parameters, reducing the number of inertial parameters from 40 to 19. As a result, while maintaining the accuracy, the computational time is reduced to 63% of that of the original dynamic model. Finally, to calibrate the dynamic model, an experimental dynamic identification is performed. 相似文献
A highly energy efficient capacitor switching technique in a successive approximation register (SAR) analog to digital converter (ADC) for biomedical applications is presented. The proposed scheme based on new switching method, which combine the LSB split capacitive technique and monotonic method can reduce the average switching energy by 99.2% compared to the conventional SAR architecture. Besides reducing energy in each comparison cycle, the suggested method also achieves an 8× reduction in total capacitance used in the digital to analog converter over the conventional one with the same resolution. The proposed ADC can find application in biomedical engineering systems and other fields which low power consumption is needed. 相似文献
SiO2 nanoparticles doped by 10 mol% Zr and 10 mol% Cu were prepared via the sol-gel method in a controled process. The effects of doping and calcination temperature on the structural and photo-catalytic properties of SiO2 nanopowders were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-Vis absorption spectroscopy. The phases of cristobalite, quartz and tridymite were found at a calcinations temperature range of 800 to 1000 °C and only cristobalite phase was formed at a temperature of 1200 °C. The degradation of methyl orange was examined under visible light radiation indicating that the effect of doped elements (Zr, Cu) on SiO2 reduces the band gap effectively. 相似文献
Water Resources Management - The majority of the cities across the developing countries have saddled water supply and quality management issues. Unfortunately, even cities with adequate water... 相似文献
We propose an accurate model to describe the I-V characteristics of a sub-90-nm metal-oxide-semiconductor field-effect transistor(MOSFET) in the linear and saturation regions for fast analytical calculation of the current.The model is based on the BSIM3v3 model.Instead of using constant threshold voltage and early voltage,as is assumed in the BSIM3v3 model,we define these voltages as functions of the gate-source voltage.The accuracy of the model is verified by comparison with HSPICE for the 90-,65-,45-,and 32-nm CMOS technologies.The model shows better accuracy than the nth-power and BSIM3v3 models.Then,we use the proposed I-V model to calculate the read static noise margin(SNM) of nano-scale conventional 6T static random-access memory(SRAM) cells with high accuracy.We calculate the read SNM by approximating the inverter transfer voltage characteristic of the cell in the regions where vertices of the maximum square of the butterfly curves are placed.The results for the SNM are also in excellent agreement with those of the HSPICE simulation for 90-,65-,45-,and 32-nm technologies.Verification in the presence of process variations and negative bias temperature instability(NBTI) shows that the model can accurately predict the minimum supply voltage required for a target yield. 相似文献
Polymer layered silicate nanocomposites have been studied for many years and due to their distinguished properties and applications, it is still the subject of many research programs. There are different methods of preparation, with the melt intercalation method as the mostly used method. Due to the thermal destructive effects of melt mixing on the polymer chains there are currently efforts to develop some new methods of preparation. A solvent/non-solvent method has been developed in this study for the preparation of ABS/clay nanocomposites. ABS nanocomposite is precipitated after addition of ethanol (non-solvent) containing organic modified montmorillonite from a THF solution while it is stirring. A kind of mixing system known as homogenizer has been used in this work. The final product has been determined having an intercalated structure with a uniform interlayer spacing of the silicate layers. The ABS nanocomposites prepared in this work has been studied by X-ray diffraction, FTIR, transmission electron microscope and thermogravimetric analysis. The effect of using homogenizer on the characteristics of the nanocomposites also has been investigated and discussed in several parts of the present work. 相似文献
In this paper, a new weighted and constrained possibilistic C-means clustering algorithm is proposed for process fault detection
and diagnosis (FDI) in offline and online modes for both already known and novel faults. A possibilistic clustering based
approach is utilized here to address some of the deficiencies of the fuzzy C-means (FCM) algorithm leading to more consistent
results in the context of the FDI tasks by relaxing the probabilistic condition in FCM cost function. The proposed algorithm
clusters the historical data set into C different dense regions without having precise knowledge about the number of the faults
in the data set. The algorithm incorporates simultaneously possibilistic algorithm and local attribute weighting for time-series
segmentation. This allows different weights to be allocated to different features responsible for the distinguished process
faults which is an essential characteristic of proper FDI operations. A set of comparative studies have been carried out on
the large-scale Tennessee Eastman industrial challenge problem and the DAMADICS actuator benchmark to demonstrate the superiority
of the proposed algorithm in process FDI applications with respect to some available alternative approaches. 相似文献
Au nanoparticles (nanoAu) with an average diameter of 60 nm were decorated on the surface of multiwalled carbon nanotubes to prepare MWCNTs-nanoAu nano-hybrids. The MWCNTs-nanoAu nano-hybrids were cast on the surface of a glassy carbon electrode and were then further modified with a layer comprising glucose oxidase and chitosan to fabricate a novel electrochemiluminescence (ECL) glucose biosensor. The biosensor showed a remarkably improved electrocatalytic activity towards luminol oxidation and significant improvement in its ECL response. The proposed ECL biosensor exhibited excellent performance for glucose detection with a wide linear range (1-1000 μM), low detection limit (0.5 μM), excellent reproducibility (0.5%) and satisfactory selectivity. 相似文献