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•The novel constraints-handling method is proposed, which is named conditional selection strategies (CSS).•The improved GSA-based algorithms including GSA-CSS and IGSA-CSS are ...proposed.•Three test systems with different sizes are used to test the proposed algorithms.•According to simulation results, IGSA-CSS outperforms basic GSA, PSO and GSA-CSS; and GSA-CSS also outperforms GSA.
Optimal reactive power dispatch (ORPD) is well known as a complex mixed integer nonlinear optimization problem where many constraints are required to handle. In the last decades, many artificial intelligence-based optimization methods have been used to solve ORPD problem. But, these optimization methods lack an effective means to handle constraints on state variables. Thus, in this paper, the novel and feasible conditional selection strategies (CSS) are devised to handle constraints efficiently in the proposed improved gravitational search algorithm (GSA-CSS). In addition, considering the weakness of GSA itself, the improved GSA-CSS (IGSA-CSS) is presented which employs the memory property of particle swarm optimization (PSO) to enhance global searching ability and utilizes the concept of opposition-based learning (OBL) for optimizing initial population. The presented GSA-CSS and IGSA-CSS methods are applied to ORPD problem on IEEE14-bus, IEEE30-bus and IEEE57-bus test systems for minimization of power transmission losses (Ploss) and voltage deviation (Vd), respectively. The comparisons of simulation results reveal that IGSA-CSS provides better results and the improvements of algorithm in this work are feasible and effective.
The paper presents light curve solutions of our observations of four new
ultrashort-period eclipsing binaries with MS components. Two of them have
periods almost at the upper limit (0.22 days) of the ...ultrashort-period
binaries, while the periods of around 0.18 days of CSS J171508.5+350658 and
CSS J214633.8+120016 are amongst the shortest known orbital periods. CSS
J171410.0+ 445850, CSS J214633.8+120016 and CSS J224326.0+154532 are
over contact binaries with fill out factors around 0.25 while CSS
J171508.5+350658 is a semidetached system. The two targets with shortest
periods consist of M dwarfs.
nema
In this note, we give a counterexample and modification of Lemma 4.4 (ii) in
1
. Moreover, the validity of Theorem 4.6 in
1
is confirmed without using Lemma 4.4 in its proof.
The effects of blending sewage sludge on the properties of coal–sludge slurry (CSS), such as solid loading, apparent viscosity, rheological behaviour and stability, were systematically investigated. ...The size and morphology of particles, and grinding efficiency were analyzed. The experimental results showed that adding sewage sludge can improve the grinding efficiency and stability of slurry. CSSs prepared from Yanzhou coal, Jiangxinzhou sewage sludge and Yangzi sewage sludge exhibit pseudo-plastic behaviour with an apparent viscosity decreasing with increasing shear rate. Both CSSs, containing 10wt% Jiangxinzhou sewage sludge and 15wt% Yangzi sewage sludge, with about 60wt% solid loading and 1200mPas apparent viscosity, are suitable for theirs handling in preparation, transport, storage, atomization, and combustion processes.
This work presents the influence of O2 during the cooling stage (CS) after the deposition of the CdTe absorber layer on the photovoltaic parameters of CdTe/PEDOT:PSS hybrid solar cells. The CdTe ...samples were processed by closed space sublimation (CSS) at a constant deposition pressure of 100 mTorr under 50 %Ar + 50 %O2 atmosphere. After CdTe deposition, the CSS system remained at a constant pressure of 50 mTorr for 10 min of the CS under different Ar + O2 atmospheres and in vacuum, in order to study the influence of the cooling atmosphere on the optical, morphological and structural properties of CdTe and on the photovoltaic parameters of the CdTe/PEDOT:PSS hybrid solar cells. In addition, different cooling times (from 10 to 90 min) were studied in an O2-only atmosphere, when the cooling temperature decreased from 500 to 300 °C inside the CSS system, at the same pressure. SEM micrographs showed changes in the surface morphology of CdTe when cooled in O2 atmosphere; while, EDS showed a slight modification in Te/Cd ratio for some samples with O2 during CS. Carrying out a cooling process in O2 atmosphere for 10 min allows improving the photovoltaic parameters Jsc, Voc, FF, and η of the obtained hybrid solar cells. For cooling times longer than 30 min, the values of Voc and Jsc started to decrease. The solar cells with cooling times of 10 and 30 min in an O2 atmosphere show in the J vs. V curves an increase mainly in the Voc, FF and shunt resistances associated with the mitigation of defects at the interfaces and inside the materials, which may be due to a passivation of the absorber material. Solar cells with an O2 cooling atmosphere also show an essential increase in the EQE response.
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We consider the highlights of our contribution are:•CdTe thin films were processed by CSS with different cooling atmospheres•The effect of O2 during the cooling of CdTe on its morphology and atomic composition•Influence of cooling time in O2 atmosphere on photovoltaic parameters of CdTe hybrid solar cells•Effect of cooling time with O2 on External Quantum Efficiency of CdTe:PEDOT:PSS solar cells
The last two decades have seen Cognitive Radio (CR) technology as an efficient mechanism to combat spectrum scarcity. Cooperative spectrum sensing (CSS) further enhances its efficiency. However, ...primary user emulation attack (PUEA) can affect the key purpose of CSS, by changing its fundamental model. This necessitates optimization of the CSS system facing a PUEA. In this paper, such optimization has been performed with the help of Deep Q- Network (DQN) learning. A smart-PUEA strategy, where the attack is made intelligently during the absence of the primary user (PU) signal, has been considered for investigation. First, the presence of a PUEA is modelled with the Markov chain. Then, the suppression of the damages done by the PUEA on the SU throughput has been performed in two CSS architectures: the decision fusion CSS and the data fusion CSS. In both the CSS architectures, the application of DQN learning is carried out by finding an optimal policy with the help of an action-value function. The optimal policy gives the optimal decision threshold and the optimal sensing time. As the data sets for the considered system are large, a multi-layered network is used for approximating the action-value function estimator. The reward is received in terms of maximized SU throughput. The performance assessment is done with an exhaustive search mechanism and beamforming based CSS. It is shown that the proposed algorithms outperform the existing algorithms in terms of the achievable sum-rate and number of iterations for convergence respectively.
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•P-CSs was preparation through H3PO4 modifying CSs.•2.The qe of MB on regenerated P-CSs maintained 91% level on native P-CSs after 4 adsorption-desorption cycles.•Electrostatic ...attraction, ion exchange are involved in adsorption of MB on P-CSs.
A novel bio-adsorbent based on H3PO4-modified corn stalks (P-CSs) was synthesized and used to adsorb methylene blue (MB) from aqueous solution. The successful modification of corn stalks by H3PO4 was verified by using XPS, FT-IR, respectively. Meanwhile, the adsorption performance and the adsorption mechanism of P-CSs were investigated. This novel bio-adsorbent performed stably over a considerably wide pH range of 6.0∼9.0. And electrostatic attraction and ion exchange were involved in adsorption of MB on P-CSs. Furthermore, the adsorption of MB by P-CSs perfectly fitted the Langmuir isotherm model (R2 = 0.997–0.999) and pseudo second order kinetic model (R2= 0.999). The qe of MB on P-CSs was 129 mg/g at 308 K by Langmuir model, and thermodynamic study showed that MB adsorption is a spontaneous exothermic process. The regeneration and re-adsorption experiments indicated P-CSs’s merit of regeneration with the recovery efficient of 91% after 4 adsorption-desorption cycles. This novel bio-adsorbent prepared in this work could achieve effective removal of MB and could be reused for 4 and more adsorption-desorption cycles for MB removal.
This letter presented several new constructions of complementary sets (CSs) with flexible sequence lengths using matrix transformations. The constructed CSs of size 4 have different lengths, namely N ...+ L and 2N + L, where N and L are the lengths for which complementary pairs exist. Also, presented CSs of size 8 have lengths N + P, P + Q and 2P + Q, where N is length of complementary pairs, P and Q are lengths of CSs of size 4 exist. The achieved designs can be easily extended to a set size of 2n+2 by recursive method. The proposed constructions generalize some previously reported constructions along with generating CSs under fewer constraints.
We give a construction of quantum LDPC codes of dimension <inline-formula> <tex-math notation="LaTeX">\Theta (\log N) </tex-math></inline-formula> and distance <inline-formula> <tex-math ...notation="LaTeX">\Theta (N/\log N) </tex-math></inline-formula> as the code length <inline-formula> <tex-math notation="LaTeX">N\to \infty </tex-math></inline-formula>. Using a product of chain complexes this construction also provides a family of quantum LDPC codes of distance <inline-formula> <tex-math notation="LaTeX">\Omega (N^{1-\alpha /2}/\log N) </tex-math></inline-formula> and dimension <inline-formula> <tex-math notation="LaTeX">\Omega (N^\alpha \log N) </tex-math></inline-formula>, where <inline-formula> <tex-math notation="LaTeX">0 \le \alpha < 1 </tex-math></inline-formula>. We also introduce and study a new operation called lifted product, which naturally generalizes the product operations for quantum codes and chain complexes. Moreover, as a simple byproduct of our results on quantum codes, we obtain a new result on classical codes. We show that for any fixed <inline-formula> <tex-math notation="LaTeX">R < 1 </tex-math></inline-formula> there exists an asymptotically good family of classical quasi-cyclic LDPC codes of rate at least <inline-formula> <tex-math notation="LaTeX">R </tex-math></inline-formula> with, in some sense, optimal circulant size <inline-formula> <tex-math notation="LaTeX">\Omega (N/\log N) </tex-math></inline-formula> as the code length <inline-formula> <tex-math notation="LaTeX">N\to \infty </tex-math></inline-formula>.
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