61 research outputs found
Dynamics of doubly stochastic quadratic operators on a finite-dimensional simplex
The present paper focuses on the dynamics of doubly stochastic quadratic operators (d.s.q.o) on a finite-
dimensional simplex. We prove that if a d.s.q.o. has no periodic points then the trajectory of any initial point inside the simplex is convergent. We show that if d.s.q.o. is not a permutation then it has no periodic points on the interior of the two dimensional (2D) simplex. We also show that this property fails in higher dimensions. In addition, the paper also discusses the dynamics classifications of extreme points of d.s.q.o. on two dimensional simplex. As such, we provide some examples of d.s.q.o. which has a property that the trajectory of any initial point tends to the center of the simplex. We also provide and example of d.s.q.o. that has infinitely many fixed points and has infinitely many invariant curves. We therefore came-up with a number of evidences. Finally, we classify the dynamics of extreme points of d.s.q.o. on 2D simplex
Reach a nonlinear consensus for MAS via doubly stochastic quadratic operators
This technical note addresses the new nonlinear protocol class of doubly stochastic quadratic operators (DSQOs) for coordination of consensus problem in multi-agent systems (MAS). We derive the conditions for ensuring that every agent reaches consensus on a desired rate of the group’s decision where the group decision value in its agent’s initial statuses varies. Besides that, we investigate a non-linear protocol sub-class of extreme DSQO (EDSQO) to reach a consensus for MAS to a common value with nonlinear low-complexity rules and fast time convergence if the interactions for each agent
are not selfish. In addition, to extend the results to reach a consensus and to avoid the selfish case we specify a general class of DSQO for reaching a consensus under any given case of initial states. The case that MAS reach a consensus by DSQO is if each member of the agent group has positive interactions of DSQO (PDSQO) with the others. The convergence of both EDSQO and PDSQO classes is found to be directed towards the centre point. Finally, experimental simulations are given to support the analysis from theoretical aspect
Design of very compact Combline Band-Pass Filter for 5G applications
NoIn this paper, a compact microstrip band-pass filter (BPF) covering the 3.4 to 3.8 GHz spectrum bandwidth for 5G wireless communications is presented. The planar filter uses three resonators, each terminated by a via to hole ground at one end and a capacitor at the other end with 50 Ω transmission line impedances for input and output terminals. The coupling between the lines is adjusted to resonate at the centre frequency with third-order band-pass Butterworth properties. The proposed combline filter is designed on an alumina substrate with a relative dielectric constant of 9.8 and a very small size of 9×5×1.2 mm3. The proposed filter is simulated and optimized using CST microwave studio software.European Union’s Horizon 2020 research and innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET-722424, UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E022936/
Behavior of Abu-Jir Fault Zone in Al-Thirthar Valley and near Habbaniya Lake Areas – Comparative Study Using Seismic Reflection Sections
A comparative study of behavior of Abu-Jir fault zone in Al-Thirthar Valley and near Al-Habbaniya Lake areas has been carried out using seismic reflection sections. Interpretation of the seismic sections showed some similarities and differences in behavior of Abu-Jir Fault Zones in both areas. The seismic sections exhibit simple flower structure in the fault zone of both Al-Thirthar Valley and near Habbaniya Lake but the flower structure in later is simpler than the former. The fault zone in Al-Thirthar Valley behaves as blind fault, whereas it reaches to the Earth's surface near Habbaniya Lake. Abu-Jir Fault Zone near Habbaniya Lake is wider than that in Thirthar Valley area. Syn-rifting due to faulting and slightly thickening has begun within both areas; occur between Alan and Hartha reflectors in Thirthar area and between Alan and Dammam reflectors near Habbaniya Lake. Abu-Jir Fault Zone near Habbaniya Lake suffered to strike slip movement less than that in Thirthar Valley because it is far from the collision suture zone between Arabian plate and Turkish and Iranian plates
Combination of FDM 3D Printing and Compressed Tablet for Preparation of Baclofen as Gastro-Floating Drug Delivery System (Conference Paper )#
This study aimed to develop an oral drug delivery system for gastro-retentive sustained drug release of baclofen by using a 3D printed capsular device since baclofen has a short half-life of 2.5 to 4 hours and has a narrow absorption window. Firstly sustained-release tablets of baclofen were formulated through the hot-melt extrusion of various thermoplastic polymers and direct compression of the extrudate, then a capsular device was designed and 3D printed to contain two air pockets to enable floating of the device and has four windows for drug release.
3D printing of the capsular device was done by an FDM printer using biodegradable PLA filament, and the sustained release tablets were inserted into the device to allow the medicine to be released into the stomach over a longer period. An in vitro buoyance test and an in vitro dissolution test were used to examine the buoyancy and sustained-release features of the formulated gastro-floating system.
Five sustained release formulas were developed using different thermoplastic polymers in hot-melt extrusion. Produced tablets were assayed for drug content, hardness, and friability while a DSC study was done on the selected formula. F 5 which contains 20% baclofen, 55% Eudragit RS-100, 20% ethylcellulose, and 5% PEG 4000 showed sustained release where the complete dissolution of the drug occurred in 12 hours, and the gastro-floating device remained floating all the time.
This method has a great potential for developing various floating drug delivery systems with the required release profile
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Recent developments of reconfigurable antennas for 4G and 5G wireless communications: A survey
YesReconfigurable antennas play important roles in smart and
adaptive systems and are the subject of many research studies. They
offer several advantages such as multifunctional capabilities, minimized volume requirements, low front-end processing efforts with
no need for a filtering element, good isolation, and sufficient out-ofband rejection; these make them well suited for use in wireless applications such as fourth generation (4G) and fifth generation (5G)
mobile terminals. With the use of active materials such as microelectromechanical systems (MEMS), varactor or p-i-n (PIN) diodes, an
antenna’s characteristics can be changed through altering the current
flow on the antenna structure. If an antenna is to be reconfigurable
into many different states, it needs to have an adequate number of
active elements. However, a large number of high-quality active elements increases cost, and necessitates complex biasing networks and
control circuitry.
We review some recently proposed reconfigurable antenna designs suitable for use in wireless communications such as cognitiveratio (CR), multiple-input multiple-output (MIMO), ultra-wideband
(UWB), and 4G/5G mobile terminals. Several examples of antennas
with different reconfigurability functions are analyzed and their performances are compared. Characteristics and fundamental properties
of reconfigurable antennas with single and multiple reconfigurability
modes are investigated.European Union’s Horizon 2020 research and innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET-722424
Dynamics classifications of extreme doubly stochastic quadratic operators on 2D simplex
We study the dynamics of extreme doubly stochastic quadratic operators (d.s.q.o.) on two dimensional (2D) simplex. We provide some examples of d.s.q.o. which have infinitely many fixed points. We prove that the trajectory of extreme d.s.q.o., starting at some interior point of the simplex is convergent. Finally, we classify the dynamics of all extreme points of d.s.q.o. on 2D
New Radiation Pattern-Reconfigurable 60-GHz Antenna for 5G Communications
Reconfigurable beam steering using circular disc microstrip patch antenna with a ring slot is proposed. The overall dimension of the antenna is 5.4 × 5.4 mm2 printed on 0.504 mm thick, RT5870 substrate with relative permittivity 2.3 and loss tangent 0.0012. The designed antenna operates at the expected 60 GHz 5G frequency band with a central coaxial probe feed. Two NMOS switches are utilized to generate three different beam patterns. Activating each switch individually results in a 70° shift in the main beam direction with constant frequency characteristics. The power gain is 3.9–4.8 dB in the three states of switch configurations. Simulated results in terms of return loss, peak gains and radiation pattern are presented and show good performance at the expected 60 GHz band for 5G applications
Effect of powdered seed of Nigella sativa administration on sub-chronic and chronic lead acetate induced hemato-biochemical and histopathological changes in Sprague Dawley rats
Lead acetate (PbAC) toxicity can occur by either ingestion or inhalation from contaminated surfaces or from the environment. Nigella sativa is a natural product with immense pharmacological properties, which include antioxidant, antibacterial, and antianemia properties. It has been showed to counter the effect of PbAC-induced hematological and biochemical changes in short-term studies. This study hypothesized that the N. sativa (NS) administration will ameliorate the deleterious effects of chronic PbAC toxicity in rats. A total of 75 Sprague Dawley rats were divided into three groups of 25 rats, and each group was further sub-divided into five groups of five rats each. Group 1 rats (negative control) were given distilled water, group 2 (positive control; PC) were given 10 mg/kg of lead acetate (PbAC) daily, and groups 3 (T1), 4 (T2), and 5 (T3) were each given 10 mg/kg of PbAC followed by graded concentrations of powdered seeds of NS; 100, 150, and 200 mg/kg, respectively. Five rats in each group were euthanized at 30, 60, and 90 days for collection of whole blood and selected organs. Whole blood was collected after euthanized via cardio puncture and used to evaluate the complete blood profile, while plasma was used for biochemical analysis. Tissue samples of the liver and kidney were fixed with 10% buffered formalin, processed, and stained with H&E and periodic acid–Schiff (PAS) for the liver. Aggression and fear were increased in the PbAC-exposed group and absent in the T3 group. There was a lower (p < 0.05) red blood cell count (RBC), packed cell volume (PCV), mean corpuscular hemoglobin concentration (MCHC), and lymphocyte count in the PC and T1 groups only. Biochemical analysis revealed elevated (p < 0.05) liver enzyme and creatinine levels in the PC and T1 groups on day 90 for AST and day 30 for ALT and creatinine. The level of alkaline phosphatase (ALP) was higher (p < 0.05) in the PC at 30 and 60 days of sampling. Other parameters, such as WBCs, prothrombin, urea, and cholesterol, were not significant in all groups. Histopathological lesions in the liver and kidneys were more severe in the PC and T1 groups, while the T2 and T3 groups showed mild lesions resulting from N. sativa administration. There was a decrease (p < 0.05) in the total PAS-stained area signifying glycogen depletion in the PC, T1, and T2 groups at 60 days and a higher distribution of the PAS-stained areas (p < 0.05) in the T3 group. At 90 days, the PC group had a lower (p < 0.05) distribution of PAS-stained areas in comparison to the other groups. The results showed the therapeutic potential of N. sativa extract in modulating both hematological and biochemical alterations induced by chronic lead acetate administration in rats
Recent Progress in the Design of 4G/5G Reconfigurable Filters
YesCurrently, several microwave filter designs contend for use in wireless communications.
Among various microstrip filter designs, the reconfigurable planar filter presents more advantages
and better prospects for communication applications, being compact in size, light-weight and
cost-effective. Tuneable microwave filters can reduce the number of switches between electronic
components. This paper presents a review of recent reconfigurable microwave filter designs,
specifically on current advances in tuneable filters that involve high-quality factor resonator filters to
control frequency, bandwidth and selectivity. The most important materials required for this field
are also highlighted and surveyed. In addition, the main references for several types of tuneable
microstrip filters are reported, especially related to new design technologies. Topics surveyed include
microwave and millimetre wave designs for 4G and 5G applications, which use varactors and
MEMSs technologies.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement H2020-MSCA-ITN-2016 SECRET-722424
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