Display omitted
•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.
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.
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>.
The main goal of present article is to see how adding graphite powder and black paint to the absorber plate can increase solar still yield. Therefore, two identical in size solar stills called ...modified solar still (MSS) and Conventional solar still (CSS) have been fabricated and tested in Patan district, Gujarat, during October 2019. MSS used graphite powder mixed with black paint, and CSS used as reference still in current research work. The current research was done with tap water as the raw water. Graphite powder concentrations have varied from 20% to 40% found 10.5 to 17% enhancement in yield. Mixing carbon powder with black paint shows improvement in a rise in water temperature and heat transfer rate than CSS. According to the results, the yield of MSS was higher than the yield of CSS during experimental days. It is concluded that the payback time of MSS with 20% weight concentration and CSS found 117 days and 121 days.
•Article presents how adding graphite powder and black paint to the absorber plate can increase solar still yield.•Two identical in size solar stills, i.e., modified solar still (MSS) and Conventional solar still (CSS), have been fabricated.•MSS used graphite powder mixed with black paint and CSS used as a reference still•20% to 40% Graphite powder concentrations found 10.5 to 17% enhancement in MSS compared with the CSS.•Payback time of MSS with 20% weight concentration and CSS found 118 days and 121 days, respectively.
Objectives
This study aimed to gather evidence for the survival benefit of cancer‐directed surgery (CDS) in metastatic head and neck cancer (M1 HNC) and identify which patients will benefit most from ...CDS.
Methods
Patients with M1 HNC were identified within the SEER database. According to whether received CDS, patients were divided into the CDS and non‐CDS groups. The bias between the two groups was minimized using Propensity Score Matching (PSM), and the prognostic role of CDS was investigated using Kaplan–Meier analysis, log‐rank test, and Cox proportional hazard models. The primary endpoint was overall survival (OS), and the secondary endpoint was cancer‐specific survival (CSS).
Results
A total of 3215 patients with M1 HNC were extracted, including 566 patients who received CDS that were 1:1 propensity score‐matched with patients who did not receive CDS. In the matched dataset, the median OS and CSS in CDS groups were significantly higher than in non‐CDS groups (OS: 19.0 vs. 9.0 months, p < 0.001; CSS: 21.0 vs. 9.0 months, p < 0.001). Meanwhile, multivariable Cox regression analysis also revealed that CDS was a favorable prognostic factor for both OS and CSS. Furthermore, subgroups of patients with M1 HNC (younger age, being married, grade I–II, oropharynx site, earlier T/N stage, radiotherapy) were inclined to benefit from CDS, while those patients who received chemotherapy failed to benefit from CDS.
Conclusions
This study indicated that CDS was associated with improved survival in M1 HNC, especially for those subpopulations that benefit more from CDS treatment.
Level of Evidence
3 Laryngoscope, 134:1288–1298, 2024
Currently, the survival benefit of cancer‐directed surgery (CDS) in distant metastatic head and neck cancer (M1 HNC) remains unclear. This study aimed to gather evidence for the survival benefit of CDS in M1 HNC and identify which patients will benefit most from CDS.
Hydrogen is considered promising for the replacement of fossil fuels in integrated energy systems through hydrogen energy storage (HES). This paper considers multiple electricity-hydrogen integrated ...charging stations (EHI-CSs) as a unit consisting of photovoltaic systems and HES systems for charging plug-in electric vehicles and refilling hydrogen fuel vehicles. In the multiple EHI-CSs unit, a set of interconnected EHI-CSs can be supplied by other EHI-CSs or power utilities and an EHI-CSs aggregator can manage the individual EHI-CSs through controllable facilities (i.e., HES system) and adjustment methods (i.e., energy transportation between subsystems). Meanwhile, a two-stage energy management system (EMS) strategy is proposed to coordinate the day-ahead scheduling and real-time dispatch. In the day-ahead scheduling stage, the aggregator minimizes the cost of the overall multiple EHI-CSs unit through optimization, and in the real-time dispatching stage, the intraday energy dispatch based model predictive control (MPC) is carried out to minimize the penalty cost. The proposed two-stage EMS strategy is evaluated through simulations and the numerical results confirm that the proposed solution outperforms the baseline solution with additional economic benefit.
•A two-stage EMS strategy is designed for the multiple EHI-CSs unit.•The multiple EHI-CSs unit is an electricity-hydrogen integrated system.•The coordinated energy management among multiple EHI-CSs is considered.•Operational cost of the multiple EHI-CSs unit is minimized.
PDF
