检索结果-南通市图书馆

robust Backstepping Control of a Quadrotor Unmanned Aerial Vehicle under Colored Noises

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2025年第1期82卷 777-798页

作者： mehmet Karahan Electrical and Electronic Engineering Department Atilim UniversityAnkara06830Turkey

Advances in software and hardware technologies have facilitated the production of quadrotor unmanned aerial vehicles(UAVs).Nowadays,people actively use quadrotor UAVs in essential missions such as search and rescue,counter-terrorism,firefighting,surveillance,and cargo *** performing these tasks,quadrotors must operate in noisy ***,a robust controller design that can control the altitude and attitude of the quadrotor in noisy environments is of great *** researchers have focused only on white Gaussian noise in their studies,whereas researchers need to consider the effects of all colored noises during the operation of the *** study aims to design a robust controller that is resistant to all colored ***,a nonlinear quadrotormodel was created with ***,a backstepping controller resistant to colored noises was *** backstepping controller was tested under Gaussian white,pink,brown,blue,and purple *** and Lyapunov-based controller designswere also carried out,and their time responses(rise time,overshoot,settling time)were compared with those of the backstepping *** the simulations,time was in seconds,altitude was in meters,and roll,pitch,and yaw references were in *** and settling time values were in seconds,and overshoot value was in *** the obtained values are examined,simulations prove that the proposed backstepping controller has the least overshoot and the shortest settling time under all noise types.

关键词： Backstepping control colored noises Gaussian noise Lyapunov stability quadrotor robustness PID control

Balo's concentric sclerosis in a patient with spontaneous remission based on magnetic resonance imaging:A case report and review of literature

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2018年第11期6卷 447-454页

作者： Ozgür Ertugrul Esra Cicekci mehmet Cudi Tuncer mehmet Ufuk Aluclu Department of radiology Memorial HospitalDiyarbakιr 21100Turkey Department of Physiotherapy University of Health SciencesGazi Yasargil Education and Research Hospital Department of Anatomy Faculty of MedicineUniversity of Dicle Department of Neurology Faculty of MedicineUniversity of Dicle

Balo's concentric sclerosis(BCS) is a rare monophasic demyelinating disease known as multiple sclerosis subtype and seen as a round lesion with variable hyper and hypodetoxification layers. Characteristic appearance can be seen as "bulb eye" or "onion bulb". The initial terminology for this neurological disorder was leukoencephalitis periaxialis concentrica; this is defined as a disease in which the white matter of the brain is destroyed in concentric layers in such a way as to leave the axial cylinders intact. This report presents a case of BCS with spontaneous healing of the patient and a mass lesion with concentric rings adjacent to the left lateral ventricle and the posterior portion of the corpus callosum with peripheral vasogenic edema. The neurological lesion of the patient was similar to the magnetic resonance imaging and clinical findings of the BCS.

关键词： Balo's concentric sclerosis Multiple sclerosis Demyelinating Magnetic resonance imaging Diffusion-weighted imaging

Fuzzy rule based seismic risk assessment of one-story precast industrial buildings

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2019年第3期18卷 631-648页

作者： mehmet Palanci Istanbul Arel University Department of Civil Engineering

Effi cient tools capable of using uncertain data to produce fast and approximate results are more practical in rapid decision-making applications when compared to conventional methods. From this point of view, this study introduces a risk assessment model for one-story precast industrial buildings by fuzzy logic which builds a bridge between uncertainty and precision. The input, output and relations of the fuzzy based risk assessment model (FBrAM) were determined by reference buildings. The Monte Carlo simulation method was used to handle uncertainties associated with the structural characteristics of the reference buildings. Section dimension, longitudinal reinforcement ratio, column height related to building elevation, confi nement ratio and seismic hazard are regarded as input and the plastic demand ratio is considered as the output parameter by the mathematical formulation of strength and deformation capacity of the buildings. The supervised learning method was used to determine the membership function of fuzzy sets. Fuzzy rules of FBrAM were constructed from Monte Carlo simulation by mapping of inputs and output. FBrAM was evaluated by a group of simulated buildings and two existing precast industrial buildings. Comparisons have shown signifi cant agreement with analytical model results in both cases. Consequently, it is anticipated that the proposed model can be used for the seismic risk mitigation of precast buildings.

关键词： fuzzy logic supervised learning precast buildings risk assessment Monte Carlo simulation

Two-and three-dimensional stability analysis of underground storage caverns in soft rock(Cappadocia, Turkey) by finite element method

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2022年第4期19卷 1182-1202页

作者： SArI mehmet Department of Mining Engineering Aksaray UniversityAksaray 68100Turkey

Engineering design in soft rocks and its stability analysis exerts many challenges to rock engineers. Many engineering works in Turkey’s Cappadocia region must face and tackle the existing sites covered by the soft rocks. This study is aimed to examine the stability condition of a typical underground storage cavern(USC) excavated in a soft rock in this region. For this purpose, two-and threedimensional stability analyses of the USCs were performed using the finite element method(FEM).Because of the inherent difficulty in characterizing soft/weak rock masses in the region using traditional classification systems, the stability of a typical USC was evaluated by representing the rock mass condition with two distinct scenarios in FEM *** these structures were unstable according to the 2D analysis conducted in rS2 software in the worstcase scenario, they were stable in the 3D analysis using rS3 software in both scenarios. Besides,feasible cover depths were examined to assess their possible effects on the factor of safety and deformation measurements. It was found that 15 m seems to be an optimal depth for excavating a typical USC in the soft rocks exposed in the region. The 3D FEM results provide valuable information to optimize the future planning and preliminary design of USCs.

关键词： Underground storage cavern Numerical modeling Soft rock FEM analysis rock mass failure

Evaluating rockfalls at a historical settlement in the Ihlara Valley(Cappadocia, Turkey) using kinematic, numerical, 2D trajectory, and risk rating methods

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2022年第12期19卷 3346-3369页

作者： SArI mehmet Department of Mining Engineering Aksaray UniversityAksaray68100Turkey

rockfalls are one of the most dangerous natural events in hilly terrains, and they substantially threaten residential areas and transport corridors in these environments. This study is aimed to analyze the risk of rockfall from a slope to nearby houses in a historical settlement with past rockfall histories. It contains numerous applications to study rockfall danger from different points of view(e.g., kinematics,numerical stability analysis, risk assessment, 2D trajectory). The rockfall kinematics revealed the statistics for different structurally controlled failure modes among the surveyed slope discontinuities,especially wedge type and block toppling were the most significant ones. Finite element analysis showed that the slope was stable under the natural condition with a safety factor of 2.19. The rockfall risk rating system calculated a medium risk for the houses downstream. Based on the field measurements, a possible rockfall profile was determined and located as an input in the 2D rockfall trajectory program. The rigid-body impact model runs utilized various shapes and sizes of blocks to simulate the rockfall events realistically. According to the 2D trajectory model results, there was no rockfall danger for the investigated downslope houses. The study showed the importance of using different analysis techniques to solve rockfall risk in protected areas based on scientific and rational approaches.

关键词： Belisirma village Cappadocia region rockfall kinematics 2D rockfall trajectory analysis rockfall risk rating system FEM modeling

Analytical and approximate solutions of(2+1)-dimensional time-fractional Burgers-Kadomtsev-Petviashvili equation

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2020年第5期72卷 21-31页

作者： mehmet Senol Department of Mathematics Nevsehir Haci Bektas Veli UniversityNevsehirTurkey

In this paper,we applied the sub-equation method to obtain a new exact solution set for the extended version of the time-fractional Kadomtsev-Petviashvili equation,namely Burgers-Kadomtsev-Petviashvili equation(Burgers-K-P)that arises in shallow water ***,using the residual power series method(rPSM),approximate solutions of the equation were obtained with the help of the Mathematica symbolic computation *** also presented a few graphical illustrations for some *** fractional derivatives were considered in the conformable *** of the obtained solutions were replaced back in the governing equation to check and ensure the reliability of the *** numerical outcomes confirmed that both methods are simple,robust and effective to achieve exact and approximate solutions of nonlinear fractional differential equations.

关键词： fractional partial differential equations Burgers-Kadomtsev-Petviashvili equation conformable fractional derivative sub-equation method residual power series method

Optimization of selective copper extraction from chalcopyrite concentrate in presence of ammonium persulfate and ammonium hydroxide

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2019年第8期26卷 946-952页

作者： mehmet Deniz Turan Department of Metallurgical and Materials Engineering Firat University

The dissolution of copper and iron from chalcopyrite concentrate in the presence of ammonium persulfate(APS)and ammonium hydroxide was investigated under atmospheric leaching *** were designed by central composite design(CCD).Under the optimum leaching conditions((NH4)2S2O8 concentration=328 g/L;NH4OH addition=16vol%;leaching temperature=321 K(48℃);leaching time=120 min;liquid-to-solid ratio=16;stirring speed=400 r/min),selective leaching was achieved.98.14%of the copper was leached,whereas iron did not pass into the solution.X-ray diffraction analysis of the leaching residue showed that iron compounds were *** the leaching results,the fact that the leaching process does not include uneconomical leaching stages such as extended milling/mechanical activation or high pressures/temperatures,and the low copper dissolution conditions,the attained selective leaching yield may be remarkable.

关键词： leaching complex reaction selectivity copper chalcopyrite

Symmetries of boundary layer equations of power-law fluids of second grade

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2008年第6期24卷 661-670页

作者： mehmet Pakdemirli Yi■it Aksoy Muhammet Yürüsoy Chaudry Masood Khalique Department of Mechanical Engineering Celal Bayar University45140 MuradiyeManisaTurkey Technical Education Faculty Afyon Kocatepe UniversityAfyonTurkey Department of Mathematical Sciences International Institute for Symmetry Analysis and Mathematical ModelingNorth-West UniversityMafikeng CampusPrivate Bag X 2046Mmabatho 2735South Afiica

A modified power-law fluid of second grade is considered. The model is a combination of power-law and second grade fluid in which the fluid may exhibit normal stresses, shear thinning or shear thickening behaviors. The equations of motion are derived for two dimensional incompressible flows, and from which the boundary layer equations are derived. Symmetries of the boundary layer equations are found by using Lie group theory, and then group classification with respect to power-law index is performed. By using one of the symmetries, namely the scaling symmetry, the partial differential system is transformed into an ordinary differential system, which is numerically integrated under the classical boundary layer conditions. Effects of power-law index and second grade coefficient on the boundary layers are shown and solutions are contrasted with the usual second grade fluid solutions.

关键词： Power-law fluid of second grade Boundarylayers Lie group theory

reductive atmospheric acid leaching of spent alkaline batteries in H_2SO_4/Na_2SO_3 solutions

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2015年第7期22卷 674-681页

作者： mehmet Hakan Morcali Faculty of Chemical and Metallurgical Engineering Istanbul Technical University

This work studies the optimum reductive leaching process for manganese and zinc recovery from spent alkaline battery paste. The effects of reducing agents, acid concentration, pulp density, reaction temperature, and leaching time on the dissolution of manganese and zinc were investigated in detail. Manganese dissolution by reductive acidic media is an intermediate-controlled process with an activation energy of 12.28 kJ＇mo1-1. After being leached, manganese and zinc were selectively precipitated with sodium hydroxide. The zinc was entirely con- verted into zincate （Zn（OH）42-） ions and thus did not co-precipitate with manganese hydroxide during this treatment （2.0 M NaOH, 90 min, 200 r/rain, pH 〉 13）. After the manganese was removed from the solution, the Zn（OH）4^2- was precipitated as zinc sulfate in the presence of sulfuric acid. The results indicated that this process could be effective in recovering manganese and zinc from alkaline batteries.

关键词： waste recycling alkaline batteries manganese zinc recovery