检索结果-南通市图书馆

Modeling and numerical simulations for a prey-predator model with interference among predators

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Modeling, simulation, and scientific Computing 2021年第1期12卷 29-52页

作者： M.s.surendar M.sambath Department of Mathematics Periyar University Salem 636011India

In this paper,we modeled a prey–predator system with interference among predators using the Crowley–Martin functional *** local stability and existence of Hopf bifurcation at the coexistence equilibrium of the system in the absence of diffusion are ***,the stability of bifurcating periodic solutions is *** derived the conditions for which nontrivial equilibrium is globally asymptotically *** addition,we study the diffusion driven instability,Hopf bifurcation of the corresponding diffusion system with zero flux boundary conditions and the Turing instability region regarding parameters are *** stability and direction of Hopf bifurcation are determined by applying the normal form theory and the center manifold *** simulations are performed to illustrate the theoretical results.

关键词： stability Crowley-Martin model Hopf bifurcation Periodic solutions Turing instability

Nash Embedding of Witten’s M-Theory and the Hawking-Hartle Quantum Wave of Dark Energy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Physics 2013年第10期4卷 1417-1428页

作者： Mohamed s. El Naschie Department of Physics Alexandria University Alexandria Egypt

Euclidean embedding of the 11-dimensional M-theory turned out to require a very large space leaving lavish amounts of 242 dimensional pseudo truly empty “regions” devoid of space and time and consequently of anything resembling ordinary physical energy density. It is shown here using Nash embedding that the ratio of “solid” M-theory spacetime to its required embedding “non-spacetime” is 1/22 for a classical theory and 1/22.18033989 for an analogous fractal theory. This then leads to a maximal ordinary energy density equation equal to that of Einstein’s famous formula E=mc2 but multiplied with in full agreement with previous results obtained using relatively more conventional methods including running the electromagnetic fine structure constant in the exact solution of the hydrogen atom. Consequently, the new equation corresponds to a quantum relativity theory which unlike Einstein’s original equation gives quantitative predictions which agree perfectly with the cosmological measurements of WMAP and the analysis of certain supernova events. Never the less in our view dark energy also exists being the energy of the quantum wave amounting to 95.5 present of the total Einstein theoretical energy which is blind to any distinction between ordinary energy of the quantum particle and the dark energy of the quantum wave. However, since measurement leads to the collapse of the Hawking-Hartle quantum wave, dark energy being a quantum wave non-ordinary energy could not possibly be measured in the usual way unless highly refined quantum wave non-demolition technology is developed if possible. It is a further reason that dark energy having a different sign to ordinary energy is the cause behind the anti gravity force which is pushing the universe apart and accelerating cosmic expansion. Consequently it can be seen as the result of anticlastic Cartan-like curvature caused by extra compactified dimensions of spacetime. A simple toy model demonstration of the effect of curvature in

关键词： Nash Euclidean Embedding Quantum Entanglement Dark Energy of the Quantum Wave Quantum Gravity Ordinary Energy of the Quantum Particle Hawking-Hartle Wave of the Cosmos Quantum Wave Non-Demolition Witten’s M-Theory

NAsA’s EM Drive Thrust from the Forces of the Quantum Vacuum of spacetime

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Aerospace science and Technology 2018年第1期3卷 1-9页

作者： Mohamed s. El Naschie Distinguished Professor Dept. of Physics Faculty of Science University of Alexandria Alexandria Egypt

Building on the various manifestations of the forces latent in the quantum vacuum of spacetime such as Hawking’s radiation and Unruh temperature, we resolve a major paradox connected to an immensely important proposal by NAsA scientists for constructing a practically fuelless spacecraft. In a nutshell, preliminary laboratory work shows that NAsA’s electromagnetic drive project is viable and several experiments and measurements show it is real. Yet the proposal violates a fundamental principle of classical mechanics, namely Newton’s third law. The resolution of this paradox is quite straight forward in principle. It is simply the case that although the proposal seems to be based on classical mechanics and classical thinking it is only superficially so. Deep at the roots, the EM drive proposal of NAsA is not classical physics but rather based on the vacuum forces of quantum cosmology and the theory of dark energy density of the universe. In fact the proposal is deeply linked to Hawking’s radiation and Unruh temperature, which is explained in some detail in the main body of the present short paper within the frame work of E-infinity Cantorian spacetime theory and D. Gross’ Heterotic superstring theory. In short the quintessence of our explanation is to regard the EM drive as a quasi electromagnetic cavity with an effective event horizon akin to that of a Hawking black hole emitting radiation causing ultimately the needed thrust to push the spacecraft forwards. In addition and by invoking fractal spacetime self similarity we show that a spacecraft will be subject to another cosmic thrust on the large scale of the entire cosmos.

关键词： EM Drive Interstellar Flight Vacuum Energy Dark Energy Cantorian spacetime Hartle-Hawking Wave Function of the Cosmos Cantorian Plasma Quantum Cosmology Casimir-Dark Energy Nano Reactor Heterotic superstrings Equations of Ordinary and Dark Energy Nonlinear Dynamics and Fractals Hawking Radiation Axion Unruh Temperature

Novel Multimodal Biometric Feature Extraction for Precise Human Identification

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Intelligent Automation & soft Computing 2023年第5期36卷 1349-1363页

作者： J.Vasavi M.s.Abirami Department of Computer science and Engineering SRM Institute of Science and TechnologyKattankulathur603203Tamil NaduIndia Department of Computational Intelligence SRM Institute of Science and TechnologyKattankulathur603203Tamil NaduIndia

In recent years,biometric sensors are applicable for identifying impor-tant individual information and accessing the control using various identiﬁers by including the characteristics like aﬁngerprint,palm print,iris recognition,and so ***,the precise identiﬁcation of human features is still physically chal-lenging in humans during their lifetime resulting in a variance in their appearance or *** response to these challenges,a novel Multimodal Biometric Feature Extraction(MBFE)model is proposed to extract the features from the noisy sen-sor data using a modiﬁed Ranking-based Deep Convolution Neural Network(RDCNN).The proposed MBFE model enables the feature extraction from differ-ent biometric images that includes iris,palm print,and lip,where the images are preprocessed initially for further *** extracted features are validated after optimal extraction by the RDCNN by splitting the datasets to train the fea-ture extraction model and then testing the model with different sets of input *** simulation is performed in matlab to test the efﬁcacy of the modal over multi-modal datasets and the simulation result shows that the proposed meth-od achieves increased accuracy,precision,recall,and F1 score than the existing deep learning feature extraction *** performance improvement of the MBFE Algorithm technique in terms of accuracy,precision,recall,and F1 score is attained by 0.126%,0.152%,0.184%,and 0.38%with existing Back Propaga-tion Neural Network(BPNN),Human Identiﬁcation Using Wavelet Transform(HIUWT),segmentation Methodology for Non-cooperative Recognition(sMNR),Daugman Iris Localization Algorithm(DILA)feature extraction techni-ques respectively.

关键词： Multimodalbiometric feature extraction ranking-baseddeepconvolution neural network noisy sensor data palm prints lip biometric iris recognition

spatial investigation of the temporal urban form to assess impact on transit services and public transportation access

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geo-spatial Information science 2012年第3期15卷 187-197页

作者： P.N.DADHICH s.HANAOKA Department of International Development Engineering Graduate School of Science&EngineeringTokyo Institute of Technology2-12-1-I4-12OokayamaMeguro-kuTokyo 152-8550Japan

The rapid urban growth in developing city increases the requirement of the efficient and sustainable public transportation *** urban growth affects the urban form,which indicates the change in human and urban development *** form affects directly and indirectly access to the public transportation system as an assessment of potential riders and proximity to stops increase transit services ***,access is one of the important aspects for the assessment of transit service *** transportation access can be represented by a coverage area and useful to estimate potential riders of public *** this study,a Geographical Information system(GIs)-based spatial statistical analysis method is used to examine the spatial relationship of different urban form indicators with population or riders of transit service in a coverage area and to ascertain how urban form influences public transportation trips in this coverage *** coverage area is delineated using a GIs-based road/street network distance *** spatial analysis results suggested that urban forms have certain impact on trips in coverage area at both ward level and zone *** statistical analysis implies that significant and positive values of spatial lag coefficient indicate a positive spatial interaction between wards and variable like total coverage area;worker density have shown positive and significant effects on trips of public transportation.

关键词： GIs spatial analysis urban form public transportation

synthesis of zeolite membranes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese science Bulletin 2004年第24期49卷 2547-2554页

作者： JIANGHaiyang ZHANGBaoquan Y.s.Lin LIYongdan schoolofChemicalEngineeringandTechnology TianjinUniversityTianjin300072China schoolofChemicalEngineeringandTechnology TianjinUniversityTianjin300072China//DepartmentofChemicalandMaterialsEngineeringUniversityofCincinnatiCincinnatiOH45221USA

Zeolite membranes offer great application potentials in membrane separation and/or reaction due to their excellent separation performance and catalytic ability. Up to present, various synthesis methods of zeolite mem- branes have been developed, including embedded method, in-situ hydrothermal synthesis method, and secondary growth method etc. Compared with the in-situ hydrothermal synthesis method, the secondary growth method possesses a variety of advantages such as easier operation, higher con- trollability in crystal orientation, microstructure and film thickness, leading to much better reproducibility. This review provides a concise summary and analysis of various synthesis methods reported in the literature. In particular, the secon- dary growth method was discussed in detail in terms of crys- tal orientation, defects and crystal grain layers. some critical issues were also highlighted, which were conducive to the improvement in the synthesis technology of zeolite mem- branes.

关键词：沸石隔膜合成工艺吸附性沉积物

Detecting and Preventing of Attacks in Cloud Computing Using Hybrid Algorithm

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Intelligent Automation & soft Computing 2023年第1期35卷 79-95页

作者： R.s.Aashmi T.Jaya Department of Computer science and Engineering CSI Institute of TechnologyThovalaiIndia Department of Electronic Communications and Engineering CSI Institute of TechnologyThovalaiIndia

Cloud computing is the technology that is currently used to provide users with infrastructure,platform,and software services *** this system,Platform as a service(Paas)offers a medium headed for a web development platform that uniformly distributes the requests and *** using Denial of service(Dos)and Distributed Denial of service(DDos)attacks abruptly interrupt these *** though several existing methods like signature-based,statistical anomaly-based,and stateful protocol analysis are available,they are not sufficient enough to get rid of Denial of service(Dos)and Distributed Denial of service(DDos)attacks and hence there is a great need for a definite *** this issue,we propose an improved hybrid algorithm which is a combination of Multivariate correlation analysis,spearman coefficient,and mitigation *** can easily differentiate common traffic and attack *** only that,it greatly helps the network to distribute the resources only for authenticated *** effects of comparing with the normalized information have shown an extra encouraging detection accuracy of 99%for the numerous Dos attack as well as DDos attacks.

关键词： Hybrid algorithm(HA) distributed denial of service(DDos) denial of service(Dos) platform as a service(Paas) infrastructure as a service(Iaas) software as a service(saas)

Transient elastography for the assessment of chronic liver disease: Ready for the clinic?

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 Gastroenterology 2007年第36期13卷 4791-4797页

作者： JFL Cobbold s Morin sD Taylor-Robinson Division of Medicine Faculty of Medicine Imperial College London London United Kingdom

Transient elastography is a recently developed non- invasive technique for the assessment of hepatic fi brosis. The technique has been subject to rigorous evaluation in a number of studies in patients with chronic liver disease of varying aetiology. Transient elastography has been compared with histological assessment of percutaneous liver biopsy, with high sensitivity and specificity for the diagnosis of cirrhosis, and has also been used to assess pre-cirrhotic disease. However, the cut-off values between different histological stages vary substantially in different studies, patient groups and aetiology of liver disease. More recent studies have examined the possible place of transient elastography in clinical practice, including risk stratifi cation for the development of complications of cirrhosis. This review describes the technique of transient elastography and discusses the interpretation of recent studies, emphasizing its applicability in the clinical setting.

关键词： Fibroscan Transient elastography Liver stiffness measurement Hepatic fibrosis Hepatitis

Contrast-enhanced harmonic endoscopic ultrasound imaging: Basic principles, present situation and future perspectives

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 Gastroenterology 2014年第42期20卷 15549-15563页

作者： María-Victoria Alvarez-sánchez Bertrand Napoléon Department of Gastroenterology H?pital Privé Jean Mermoz Department of Gastroenterology Complejo Hospitalario de Pontevedra

Over the last decade, the development of stabilised microbubble contrast agents and improvements in available ultrasonic equipment, such as harmonic imaging, have enabled us to display microbubble enhancements on a greyscale with optimal contrast and spatial resolution. Recent technological advances made contrast harmonic technology available for endoscopic ultrasound(EUs) for the first time in 2008. Thus, the evaluation of microcirculation is now feasible with EUs, prompting the evolution of contrast-enhanced EUs from vascular imaging to images of the perfused tissue. Although the relevant experience is still preliminary, several reports have highlighted contrast-enhanced harmonic EUs(CHEUs) as a promising noninvasive method to visualise and characterise lesions and to differentiate benign from malignant focal lesions. Even if histology remains the gold standard, the combination of CH-EUs and EUs fine needle aspiration(EUs-FNA) can not only render EUs more accurate but may also assist physicians inmaking decisions when EUs-FNA is inconclusive,increasing the yield of EUs-FNA by guiding the puncture with simultaneous imaging of the *** development of CH-EUs has also opened up exciting possibilities in other research areas,including monitoring responses to anticancer chemotherapy or to ethanolinduced pancreatic tissue ablation,anticancer therapies based on ultrasound-triggered drug and gene delivery,and therapeutic adjuvants by contrast ultrasound-induced *** harmonic imaging is gaining popularity because of its efficacy,simplicity and noninvasive nature,and many expectations are currently resting on this *** its potential is confirmed in the near future,contrast harmonic imaging will become a standard practice in EUs.

关键词： Microbubbles Contrast agents Contrast-enhanced harmonic endoscopic ultrasound Pancreatic tumour Gastrointestinal submucosal tumour