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Computer Modeling in Engineering & Sciences 2019年第12期121卷 801-813页

作者： D.vijeswaran v.manikandan Department of Electrical and Electronics Engineering Coimbatore Institute of TechnologyCoimbatore 641014India 不详

In a cyber-physical micro-grid system,wherein the control functions are executed through open communication channel,stability is an important issue owing to the factors related to the time-delay encountered in the data *** of feedback variable as discrete data packets in communication network invariably introduces inevitable time-delays in closed loop control *** delay,depending upon the network traffic condition,inherits a time-varying characteristic;nevertheless,it adversely impacts the system performance and *** load perturbations in a micro-grid system are considerably influenced by the presence of fluctuating power generators like wind and solar *** these non-conventional energy sources are integrated into the power grid through power electronic interface circuits that usually works at high switching frequency,noise signals are introduced into the micro-grid system and these signals gets super-imposed to the load *** on this back ground,in this paper,the delay-dependent stability issue of networked micro-grid system combined with time-varying feedback loop delay and uncertain load perturbations is investigated,and a deeper insight has been presented to infer the impact of time-delay on the variations in the system *** classical Lyapunov-Krasovskii method is employed to address the problem,and using a standard benchmark micro-grid system,and the proposed stability criterion is validated.

关键词： Delay-dependent stability time-varying delay open communication network nonlinear perturbations Lyapunov-Krasovskii functional linear Matrix Inequality(LMI)

Modeling of Canonical Switching Cell Converter Using Genetic Algorithm

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Computer Modeling in Engineering & Sciences 2017年第1期113卷 109-116页

作者： T.v.viknesh v.manikandan Department of Electrical and Electronics Engineering Coimbatore Institute of TechnologyCoimbatore-641014India

The working of Canonical switching cell(CSC)converter was studied and its equivalent circuit during ON and OFF states were *** space model of CSC converter in ON and OFF states were developed using the Kirchhoff *** state space matrices were used to construct the transfer functions of ON&OFF *** step response of the converter was simulated using *** step response curve was obtained using different values of circuit components(L,C1,C2 and RL)and *** characteristic parameters such as rise time,overshoot,settling time,steady state error and stability were determined using the step response *** response curve shows that there is no overshoot;the rise time and settling time are very low as expected for a converter and its stability is very high but the amplitude is *** circuit was tuned to attain the expected amplitude using PID controller with the help of Genetic *** excellent results of circuits’characteristic parameters are very useful guideline for constructing such CSC converters for DC-DC *** circuit characteristic parameters are useful in constructing such CSC converters for DCDC conversions in driving solar energy using solar panel.

关键词： Canonical switching cell converter state-space methods DC-DC converter step response stability power system modeling switching circuits genetic algorithm PID

Buck Converter Current Measurement Using Differential Amplifier

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Intelligent Automation & Soft Computing 2023年第2期35卷 1387-1402页

作者： P.Rajeswari v.manikandan Department of Electrical and Electronics Engineering Coimbatore Institute of TechnologyCoimbatore641014India

The accuracy of the measured current is a preeminent parameter for Current Control based Power Converter applications to ensure genuine operation of the designed *** current measurement accuracy can be affected by several parameters which includes the type of technology used,components used for the selected technology,aging,usage,operating and environmental *** effect of gain resistors and their manufacturing tolerances on differential ampliﬁer-based buck converter current measurement is investigated in this *** analysis mainly focused on the output voltage variation and its accuracy with respect to the change in gain resistance *** gain resistors with 5%,1%,0.5%and 0.1%manufacturing tolerances taken for the worst-case analysis and the calculated performance results are compared and veriﬁed with the simula-tion *** Operational ampliﬁers(Op-Amp)for high frequency power con-verter applications must operate in a high frequency noise environment and the intended current measuring system must manage common mode noise distur-bances paired with the signal to be *** on the Common Mode Rejec-tion Ratio(CMRR)the common mode voltages and noise signals will effectively getﬁltered *** CMRR results in lower common mode signal rejection,resulting in poor precision and noise *** differential ampliﬁers,the CMRR predominantly depends on gain ***,the variations in Common Mode Rejection Ratio due to gain resistor tolerances also analyzed and compared with the output voltage *** the effects of resistor tolerances,this paper also examines the effect of Op-Amp offset voltage on output accuracy spe-ciﬁcally for low magnitude input *** obtained results from this analysis clearly shows that the gain resistors with 0.1%tolerance gives maximum accuracy with improved CMRR and accuracy at low magnitude input currents will get well improved by using Op-Amps with Low Offset voltage speciﬁcation

关键词： Buck converter common mode rejection ratio common mode gain current sensing differential ampliﬁer differential mode gain shunt resistor

Nature Inspired Improved Firefly Algorithm for Node Clustering in WSNs

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Computers, Materials & Continua 2020年第8期64卷 753-776页

作者： v.manikandan M.Sivaram Amin Salih Mohammed v.Porkodi Department of Computer Networking College of Engineering and Computer ScienceLebanese French UniversityErbil44001Iraq College of Engineering and Computer Science Lebanese French UniversityErbil44001Iraq Department of Information Technology College of Engineering and Computer ScienceLebanese French UniversityErbil44001Iraq

Wireless Sensor Networks(WSNs)comprises low power devices that are randomly distributed in a geographically isolated *** energy consumption of nodes is an essential factor to be ***,an improved energy management technique is designed in this investigation to reduce its consumption and to enhance the network’s *** can be attained by balancing energy clusters using a meta-heuristic Firefly algorithm model for network *** improved technique is based on the cluster head selection technique with measurement of the tour length of *** Division Multiple Access(TDMA)scheduler is also improved with the characteristics/behavior of fireflies and also *** last,the development approach shows the progression of the network lifetime,the total number of selected Cluster Heads(CH),the energy consumed by nodes,and the number of packets *** approach is compared with Ad hoc On-Demand Distance vector(AODv),Dynamic Source Routing(DSR)and Low Energy Adaptive Clustering Hierarchy(LEAH)*** is performed in MATLAB with the numerical outcomes showing the efficiency of the proposed *** energy consumption of sensor nodes is reduced by about 50%and increases the lifetime of nodes by 78%more than AODv,DSR and LEACH *** parameters such as cluster formation,end to end delay,percentage of nodes alive and packet delivery ratio,are also evaluated...The anticipated method shows better trade-off in contrast to existing techniques.

关键词： Cluster head wireless sensor network LEAH TDMA firefly AODv DSR

Secure Localization Based Authentication (SLA) Strategy for Data Integrity in WNS

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Computers, Materials & Continua 2021年第6期67卷 4005-4018页

作者： v.manikandan M.Sivaram Amin Salih Mohammed v.Porkodi K.Shankar Assistant Professor Research Research CenterLebanese French UniversityErbil44001Iraq vice President Lebanese French UniversityErbil44001Iraq Department of Information Technology College of Engineering and Computer ScienceLebanese French UniversityErbil44001Iraq Department of Computer Applications Alagappa UniversityKaraikudi630003India

Wireless Sensor Networks(WSN)has been extensively utilized as a communication model in Internet of Things(IoT).As well,to offer service,numerous IoT based applications need effective transmission over unstable *** ensure reliability,prevailing investigations exploit multiple candidate forwarders over geographic opportunistic routing in ***,these models are affected by crucial denial of service(DoS)attacks,where huge amount of invalid data are delivered intentionally to the receivers to disturb the functionality of ***,secure localization based authentication(SLA)is presented to fight against DoS attack,and to fulfil the need of reliability and *** examining state information,SLA projects a trust model to enhance efficacy of data ***,of the prevailing opportunistic protocols,SLA guarantees data integrity by modelling a trust based authentication,providing protection against DoS attackers and diminishing computational ***,this model acts as a verification strategy to accelerate?attackers and to handle *** strategy helps SLA in eliminating duplicate transmission and by continuous verification that results from conventional opportunistic *** is performed in a MATLAB environment that offers authentic and reliable delivery by consuming approximately 50%of the cost in contrast to other *** anticipated model shows better trade off in comparison to the prevailing ones.

关键词： Wireless sensor networks opportunistic routing secure localization based authentication denial of service computational cost

MicroRNAs as potential diagnostic biomarkers for bipolar disorder

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Neural Regeneration Research 2025年第6期20卷 1681-1695页

作者： Bridget Martinez Philip v.Peplow Department of Pharmacology University of Nevada-RenoRenoNVUSA Department of Medicine University of Nevada-RenoRenoNVUSA Department of Anatomy University of OtagoDunedinNew Zealand

Abnormal expression of microRNAs is connected to brain development and disease and could provide novel biomarkers for the diagnosis and prognosis of bipolar disorder. We performed a PubMed search for microRNA biomarkers in bipolar disorder and found 18 original research articles on studies performed with human patients and published from January 2011 to June 2023. These studies included microRNA profiling in bloodand brain-based materials. From the studies that had validated the preliminary findings,potential candidate biomarkers for bipolar disorder in adults could be miR-140-3p,-30d-5p,-330-5p,-378a-5p,-21-3p,-330-3p,-345-5p in whole blood, miR-19b-3p,-1180-3p,-125a-5p, let-7e-5p in blood plasma, and miR-7-5p,-23b-5p,-142-3p,-221-5p,-370-3p in the blood serum. Two of the studies had investigated the changes in microRNA expression of patients with bipolar disorder receiving treatment. One showed a significant increase in plasma miR-134 compared to baseline after 4 weeks of treatment which included typical antipsychotics, atypical antipsychotics, and benzodiazepines. The other study had assessed the effects of prescribed medications which included neurotransmitter receptorsite binders(drug class B) and sedatives, hypnotics, anticonvulsants, and analgesics(drug class C) on microRNA results. The combined effects of the two drug classes increased the significance of the results for miR-219 and-29c with miR-30e-3p and-526b* acquiring significance. MicroRNAs were tested to see if they could serve as biomarkers of bipolar disorder at different clinical states of mania, depression, and euthymia. One study showed that upregulation in whole blood of miR-9-5p,-29a-3p,-106a-5p,-106b-5p,-107,-125a-3p,-125b-5p and of miR-107,-125a-3p occurred in manic and euthymic patients compared to controls, respectively, and that upregulation of miR-106a-5p,-107 was found for manic compared to euthymic patients. In two other studies using blood plasma,downregulation of miR-134 was observed i

关键词： biomarker bipolar disorder blood leukocytes blood plasma blood plasma extracellular vesicles/exosomes blood serum brain tissue brain tissue extracellular vesicles/exosomes lymphoblastoid cell lines microRNA neural progenitor cells whole blood

Autism spectrum disorder:difficulties in diagnosis and microRNA biomarkers

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Neural Regeneration Research 2025年第10期20卷 2776-2786页

We performed a PubMed search for microRNAs in autism spectrum disorder that could serve as diagnostic biomarkers in patients and selected 17 articles published from January 2008 to December 2023,of which 4 studies were performed with whole blood,4 with blood plasma,5 with blood serum,1 with serum neural cell adhesion molecule L1-captured extracellular vesicles,1 with blood cells,and 2 with peripheral blood mononuclear *** of the studies involved children and the study cohorts were largely *** of the studies had performed microRNA sequencing or quantitative polymerase chain reaction assays to measure microRNA *** five studies had used real-time polymerase chain reaction assay to validate microRNA expression in autism spectrum disorder subjects compared to *** microRNAs that were validated in these studies may be considered as potential candidate biomarkers for autism spectrum disorder and include miR-500a-5p,-197-5p,-424-5p,-664a-3p,-365a-3p,-619-5p,-664a-3p,-3135a,-328-3p,and-500a-5p in blood plasma and miR-151a-3p,-181b-5p,-320a,-328,-433,-489,-572,-663a,-101-3p,-106b-5p,-19b-3p,-195-5p,and-130a-3p in blood serum of children,and miR-15b-5p and-6126 in whole blood of *** important limitations were identified in the studies reviewed,and need to be taken into account in future *** studies are warranted with children and adults having different levels of autism spectrum disorder severity and consideration should be given to using animal models of autism spectrum disorder to investigate the effects of suppressing or overexpressing specific microRNAs as a novel therapy.

关键词： autism spectrum disorder biomarker blood cells blood plasma blood serum diagnosis microRNA peripheral blood mononuclear cells serum neural cell adhesion molecule L1-captured extracellular vesicles whole blood

MicroRNAs as potential biomarkers for diagnosis of post-traumatic stress disorder

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Neural Regeneration Research 2025年第7期20卷 1957-1970页

Post-traumatic stress disorder is a mental disorder caused by exposure to severe traumatic life ***,there are no validated biomarkers or laboratory tests that can distinguish between trauma survivors with and without post-traumatic stress *** addition,the heterogeneity of clinical presentations of post-traumatic stress disorder and the overlap of symptoms with other conditions can lead to misdiagnosis and inappropriate *** suggests that this condition is a multisystem disorder that affects many biological systems,raising the possibility that peripheral markers of disease may be used to diagnose post-traumatic stress *** performed a PubMed search for microRNAs(miRNAs)in post-traumatic stress disorder(PTSD)that could serve as diagnostic biomarkers and found 18 original research articles on studies performed with human patients and published January 2012 to December *** included four studies with whole blood,seven with peripheral blood mononuclear cells,four with plasma extracellular vesicles/exosomes,and one with serum *** of these studies had also used whole *** studies were excluded as they did not involve microRNA *** of the studies had collected samples from adult male veterans who had returned from deployment and been exposed to combat,and only two were from recently traumatized adult *** measuring miRNA expression levels,many of the studies had used microarray miRNA analysis,miRNA Seq analysis,or NanoString *** six studies had used real time polymerase chain reaction assay to determine/validate miRNA expression in PTSD subjects compared to *** miRNAs that were found/validated in these studies may be considered as potential candidate biomarkers for PTSD and include miR-3130-5p in whole blood;miR-193a-5p,-7113-5p,-125a,-181c,and-671-5p in peripheral blood mononuclear cells;miR-10b-5p,-203a-3p,-4488,-502-3p,-874-3p,-5100,and-7641 in plasma extracellular vesicles/

关键词： biomarker diagnosis microRNA peripheral blood mononuclear cells plasma extracellular vesicles/exosomes post-traumatic stress disorder serum exosomes whole blood whole plasma

Semantic Segmentation of Lumbar vertebrae Using Meijering U-Net(MU-Net)on Spine Magnetic Resonance Images

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 733-757页

作者： Lakshmi S v v Shiloah Elizabeth Darmanayagam Sunil Retmin Raj Cyril Department of Computer Science and Engineering College of Engineering GuindyAnna UniversityChennai600025India Department of Information Technology Madras Institute of TechnologyAnna UniversityChrompetChennai600044India

Lower back pain is one of the most common medical problems in the world and it is experienced by a huge percentage of people *** to its ability to produce a detailed view of the soft tissues,including the spinal cord,nerves,intervertebral discs,and vertebrae,Magnetic Resonance Imaging is thought to be the most effective method for imaging the *** semantic segmentation of vertebrae plays a major role in the diagnostic process of lumbar *** is difficult to semantically partition the vertebrae in Magnetic Resonance Images from the surrounding variety of tissues,including muscles,ligaments,and intervertebral discs.U-Net is a powerful deep-learning architecture to handle the challenges of medical image analysis tasks and achieves high segmentation *** work proposes a modified U-Net architecture namely MU-Net,consisting of the Meijering convolutional layer that incorporates the Meijering filter to perform the semantic segmentation of lumbar vertebrae L1 to L5 and sacral vertebra ***-colour mask images were generated and used as ground truth for training the *** work has been carried out on 1312 images expanded from T1-weighted mid-sagittal MRI images of 515 patients in the Lumbar Spine MRI Dataset publicly available from Mendeley *** proposed MU-Net model for the semantic segmentation of the lumbar vertebrae gives better performance with 98.79%of pixel accuracy(PA),98.66%of dice similarity coefficient(DSC),97.36%of Jaccard coefficient,and 92.55%mean Intersection over Union(mean IoU)metrics using the mentioned dataset.

关键词： Computer aided diagnosis(CAD) magnetic resonance imaging(MRI) semantic segmentation lumbar vertebrae deep learning U-Net model

An SPH Framework for Earthquake-Induced Liquefaction Hazard Assessment of Geotechnical Structures

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 251-277页

作者： Sourabh Mhaski G.v.Ramana Department of Civil Engineering Indian Institute of Technology DelhiNew Delhi110016India

Earthquake-induced soil liquefaction poses significant risks to the stability of geotechnical structures *** understanding of the liquefaction triggering,and the post-failure large deformation behaviour is essential for designing resilient *** present study develops a Smoothed Particle Hydrodynamics(SPH)framework for earthquake-induced liquefaction hazard assessment of geotechnical *** coupled flowdeformation behaviour of soils subjected to cyclic loading is described using the PM4Sand model implemented in a three-phase,single-layer SPH framework.A staggered discretisation scheme based on the stress particle SPH approach is adopted to minimise numerical inaccuracies caused by zero-energy modes and tensile ***,non-reflecting boundary conditions for seismic analysis of semi-infinite soil domains using the SPH method are *** numerical framework is employed for the analysis of cyclic direct simple shear test,seismic analysis of a level ground site,and liquefaction-induced failure of the Lower San Fernando *** agreement for liquefaction triggering and post-failure behaviour demonstrates that the SPH framework can be utilised to assess the effect of seismic loading on field-scale geotechnical *** present study also serves as the basis for future advancements of the SPH method for applications related to earthquake geotechnical engineering.

关键词： Earthquake seismic liquefaction stress particle PM4Sand smoothed particle hydrodynamics(SPH)