Enhanced GSA-Based Optimization for Minimization of Power Losses in Power System

Gravitational Search Algorithm (GSA) is a heuristic method based on Newton’s law of gravitational attraction and law of motion. In this paper, to further improve the optimization performance of GSA, the memory characteristic of Particle Swarm Optimization (PSO) is employed in GSAPSO for searching a better solution. Besides, to testify the prominent strength of GSAPSO, GSA, PSO, and GSAPSO are applied for the solution of optimal reactive power dispatch (ORPD) of power system. Conventionally, ORPD is defined as a problem of minimizing the total active power transmission losses by setting control variables while satisfying numerous constraints. Therefore ORPD is a complicated mixed integer nonlinear optimization problem including many constraints. IEEE14-bus, IEEE30-bus, and IEEE57-bus test power systems are used to implement this study, respectively. The obtained results of simulation experiments using GSAPSO method, especially the power loss reduction rates, are compared to those yielded by the other modern artificial intelligence-based techniques including the conventional GSA and PSO methods. The results presented in this paper reveal the potential and effectiveness of the proposed method for solving ORPD problem of power system

WTC2005-63258 RESEARCH ON THE IDENTIFICATION METHODS OF FRICTION IN KINEMATICAL JOINTS OF MECHANICAL SYSTEMS

ABSTRACT This paper describes two approaches for the simultaneous identification of the coulomb and viscous parameters in kinematical joints. One is a time-domain method (TDM) and the other is a frequency-domain method (FDM). Simulation shows that both of the two methods have good performances in identifying friction at high SNR (90dB). But at low SNR (20dB), the estimation accuracy of the frequency-domain method is higher than that of the time-domain method. A field experiment employing a linkage mechanism driven by motor is also carried out. The experimental results obtained by the two approaches are almost identical under different experiment conditions. It has been concluded that the presented identification methods of friction in kinematical joints are correct and applicable. INTRODUCTION Kinematical joint is an absolutely necessary structural connection in mechanical systems. The kinematical joint is responsible for transferring energy to a remote site, and may change the type of motion, as needed. The characteristics of kinematical joints have been studied in many paper

The Value of Handheld COPD-6 Spirometry for Early COPD Detection in High Risk Elderly Population in Community

BackgroundChronic obstructive pulmonary disease (COPD) is a common chronic disease of the respiratory tract, and lung function is necessary for the diagnosis of COPD. However, conventional pulmonary function meters are not suitable for a large number of physical examinations in the community. In recent years, it is recommended to use spirometry for COPD screening and management both at home and abroad. However, there is still a lack of relevant data on its consistency and effectiveness with conventional lung function.ObjectiveTo explore the value of handheld COPD-6 spirometry for early COPD detection in high risk elderly population in community.MethodsFrom January 2018 to December 2019 at Dongshan Community Health Service Center, Jiangning District, Nanjing City, a free physical examination was performed on the elder population over 60 years who had high risk factors of COPD. Handheld COPD-6 spirometry was performed pre- and post-bronchodilator, the forced expiratory volume in one second (FEV1) , the forced expiratory volume in one second as a percentage of the predicted value (FEV1%prep) , the forced expiratory volume in six second (FEV6) , the percentage of forced expiratory volume in six second to the predicted value (FEV6%prep) , and the value of FEV1/FEV6 were evaluated and recorded. With FEV1/FEV6<80% as the initial screening positive pre-bronchodilator, retests were performed both with handheld COPD-6 spirometry and confirmatory spirometry after inhaling bronchodilator. Using FEV1/Forced vital capacity (FVC) <70% as the gold standard by confirmatory spirometry, receiver-operator characteristic (ROC) curve analysis was used to obtain the best diagnostic threshold of FEV1/FEV6. Sensitivity, specificity, positive predictive value, and negative predictive value were used to evaluate the diagnostic value of the handheld COPD-6 spirometer.ResultsOut of the 382 participants, COPD was confirmed in 75 according to FEV1/FVC<70% post-bronchodilator. There was no statistically significant difference between FEV1%pred pre- and post-bronchodilator by handheld COPD-6 spirometry (t=-0.971, P=0.703) ; There was no statistically significant difference among FEV1%pred in two tests (t=-2.352, -1.429; P=0.396, 0.058) . The FEV1%pred detected by handheld COPD-6 spirometry post-bronchodilation was positively correlated with confirmatory spirometry (r=0.969, P<0.05) . Compared with FVC%pred and FEV6%pred post-bronchodilation, the difference was statistically significant (t=-3.170, P=0.005) ; and the FEV6%pred was positively correlated with the FVC%pred (r=0.653, P<0.05) . There was no statistically significant difference between FEV1/FEV6 and FEV1/FVC post-bronchodilation (t=1.735, P=0.084) ; and there was substantial agreement between the two diagnostic (r=0.871, P<0.05) . The FEV1/FEV6 cut-off with the greatest sum of sensitivity and specificity was 71% pre-bronchodilator, the sensitivity, specificity, positive and negative predictive values were 80.0%, 79.2%, 90.6% and 48.5% respectively. The greatest sum of sensitivity and specificity was 75% post-bronchodilator, the sensitivity, specificity, positive and negative predictive values were 80.0%, 98.8%, 98.4% and 58.3% respectively.ConclusionIt is feasible to use FEV1/FEV6 as an indicator to screen COPD patients in elderly high-risk populations. It is recommended to use FEV1/FEV6<71% before bronchodilation and FEV1/FEV6<75% after diastole as the screening criteria

Photosynthetic Performance and Anti-Oxidative Response of Cornus Controversa Seedlings Under Cadmium and Lead Stress

The photosynthetic efficiency of Cornus controversa leaves was decreased significantly under Cd treatment while it was not affected by Pb exposure. Cd decreased while Pb treatment increased the chlorophyll contents of Cornus controversa leaves. Furthermore, the peroxidase (GPX) activities were decreased after Cd treatment while elevated by Pb exposure in Cornus controvera seedlings. In addition, both Cd and Pb exposures increased the malondialdehyde (MDA) and proline contents and elevated the superoxide dismutase (SOD) activities of Cornus controvera seedlings. Collectively, these results indicated that Cornus controversa may be more tolerant to Pb than Cd toxicity. This finding will contribute to the evaluation of planting Cornus controversa in heavy metal polluted soil conditions

Truck model recognition for an automatic overload detection system based on the improved MMAL-Net

Efficient and reliable transportation of goods through trucks is crucial for road logistics. However, the overloading of trucks poses serious challenges to road infrastructure and traffic safety. Detecting and preventing truck overloading is of utmost importance for maintaining road conditions and ensuring the safety of both road users and goods transported. This paper introduces a novel method for detecting truck overloading. The method utilizes the improved MMAL-Net for truck model recognition. Vehicle identification involves using frontal and side truck images, while APPM is applied for local segmentation of the side image to recognize individual parts. The proposed method analyzes the captured images to precisely identify the models of trucks passing through automatic weighing stations on the highway. The improved MMAL-Net achieved an accuracy of 95.03% on the competitive benchmark dataset, Stanford Cars, demonstrating its superiority over other established methods. Furthermore, our method also demonstrated outstanding performance on a small-scale dataset. In our experimental evaluation, our method achieved a recognition accuracy of 85% when the training set consisted of 20 sets of photos, and it reached 100% as the training set gradually increased to 50 sets of samples. Through the integration of this recognition system with weight data obtained from weighing stations and license plates information, the method enables real-time assessment of truck overloading. The implementation of the proposed method is of vital importance for multiple aspects related to road traffic safety

Integrated transcriptomic and metabolomic data reveal the cold stress responses molecular mechanisms of two coconut varieties

Among tropical fruit trees, coconut holds significant edible and economic importance. The natural growth of coconuts faces a challenge in the form of low temperatures, which is a crucial factor among adverse environmental stresses impacting their geographical distribution. Hence, it is essential to enhance our comprehension of the molecular mechanisms through which cold stress influences various coconut varieties. We employed analyses of leaf growth morphology and physiological traits to examine how coconuts respond to low temperatures over 2-hour, 8-hour, 2-day, and 7-day intervals. Additionally, we performed transcriptome and metabolome analyses to identify the molecular and physiological shifts in two coconut varieties displaying distinct sensitivities to the cold stress. As the length of cold stress extended, there was a prominent escalation within the soluble protein (SP), proline (Pro) concentrations, the activity of peroxidase (POD) and superoxide dismutase (SOD) in the leaves. Contrariwise, the activity of glutathione peroxidase (GSH) underwent a substantial reduction during this period. The widespread analysis of metabolome and transcriptome disclosed a nexus of genes and metabolites intricately cold stress were chiefly involved in pathways centered around amino acid, flavonoid, carbohydrate and lipid metabolism. We perceived several stress-responsive metabolites, such as flavonoids, carbohydrates, lipids, and amino acids, which unveiled considerably, lower in the genotype subtle to cold stress. Furthermore, we uncovered pivotal genes in the amino acid biosynthesis, antioxidant system and flavonoid biosynthesis pathway that presented down-regulation in coconut varieties sensitive to cold stress. This study broadly enriches our contemporary perception of the molecular machinery that contributes to altering levels of cold stress tolerance amid coconut genotypes. It also unlocks several unique prospects for exploration in the areas of breeding or engineering, aiming to identifying tolerant and/or sensitive coconut varieties encompassing multi-omics layers in response to cold stress conditions

The metagenome of the female upper reproductive tract

publishedVersio

COSMOS-Web: Intrinsically Luminous z≳\gtrsim10 Galaxy Candidates Test Early Stellar Mass Assembly

We report the discovery of 15 exceptionally luminous $10\lesssim z\lesssim14$ candidate galaxies discovered in the first 0.28 deg$^2$ of JWST/NIRCam imaging from the COSMOS-Web Survey. These sources span rest-frame UV magnitudes of $-20.5>M_{\rm UV}>-22$, and thus constitute the most intrinsically luminous $z\gtrsim10$ candidates identified by JWST to-date. Selected via NIRCam imaging with Hubble ACS/F814W, deep ground-based observations corroborate their detection and help significantly constrain their photometric redshifts. We analyze their spectral energy distributions using multiple open-source codes and evaluate the probability of low-redshift solutions; we conclude that 12/15 (80%) are likely genuine $z\gtrsim10$ sources and 3/15 (20%) likely low-redshift contaminants. Three of our $z\sim12$ candidates push the limits of early stellar mass assembly: they have estimated stellar masses $\sim5\times10^{9}\,M_\odot$, implying an effective stellar baryon fraction of $\epsilon_{\star}\sim0.2-0.5$, where $\epsilon_{\star}\equiv M_{\star}/(f_{b}M_{halo})$. The assembly of such stellar reservoirs is made possible due to rapid, burst-driven star formation on timescales $<$100\,Myr where the star-formation rate may far outpace the growth of the underlying dark matter halos. This is supported by the similar volume densities inferred for $M_\star\sim10^{10}\,M_\odot$ galaxies relative to $M_\star\sim10^{9}\,M_\odot$ -- both about $10^{-6}$ Mpc$^{-3}$ -- implying they live in halos of comparable mass. At such high redshifts, the duty cycle for starbursts would be of order unity, which could cause the observed change in the shape of the UVLF from a double powerlaw to Schechter at $z\approx8$. Spectroscopic redshift confirmation and ensuing constraints of their masses will be critical to understanding how, and if, such early massive galaxies push the limits of galaxy formation in $\Lambda$CDM.Comment: 30 pages, 9 figures; ApJ submitte

Unveiling the distant Universe: Characterizing z≥9z\ge9 Galaxies in the first epoch of COSMOS-Web

We report the identification of 15 galaxy candidates at $z\ge9$ using the initial COSMOS-Web JWST observations over 77 arcmin$^2$ through four NIRCam filters (F115W, F150W, F277W, F444W) with an overlap with MIRI (F770W) of 8.7 arcmin$^2$. We fit the sample using several publicly-available SED fitting and photometric redshift codes and determine their redshifts between $z=9.3$ and $z=10.9$ ($\langle z\rangle=10.0$), UV-magnitudes between M$_{\rm UV}$ = $-$21.2 and $-$19.5 (with $\langle$M$_{\rm UV}\rangle=-20.2$) and rest-frame UV slopes ($\langle \beta\rangle=-2.4$). These galaxies are, on average, more luminous than most $z\ge9$ candidates discovered by JWST so far in the literature, while exhibiting similar blue colors in their rest-frame UV. The rest-frame UV slopes derived from SED-fitting are blue ($\beta\sim$[$-$2.0, $-$2.7]) without reaching extremely blue values as reported in other recent studies at these redshifts. The blue color is consistent with models that suggest the underlying stellar population is not yet fully enriched in metals like similarly luminous galaxies in the lower redshift Universe. The derived stellar masses with $\langle \log_{\rm 10} ($M$_\star/$M$_\odot)\rangle\approx8-9$ are not in tension with the standard $\Lambda$CDM model and our measurement of the volume density of such UV luminous galaxies aligns well with previously measured values presented in the literature at $z\sim9-10$. Our sample of galaxies, although compact, are significantly resolved.Comment: Submitted to Ap