检索结果-南通市图书馆

npj Computational Materials 2020年第1期6卷 723-730页

作者： Kyle P.Kelley Linglong Li Yao Ren Yoshitaka Ehara Hiroshi Funakubo Suhas Somnath Stephen Jesse Ye Cao ramakrishnan kannan Rama K.Vasudevan Sergei V.Kalinin Center for Nanophase Materials Sciences Oak Ridge National LaboratoryOak RidgeTN 37831USA Department of Physics Tsinghua UniversityBeijingChina Department of Materials Science and Engineering University of Texas at ArlingtonArlingtonTX 76019USA Department of Communications Engineering National Defense AcademyHashirimizuYokosuka 239-8686Japan Department of Material Science and Engineering Tokyo Institute of TechnologyYokohama 226‐8502Japan National Center for Computational Sciences Oak Ridge National LaboratoryOak RidgeTN 37831USA Computer Science and Mathematics Division Oak Ridge National LaboratoryOak RidgeTN 37831USA

Spatially resolved time and voltage-dependent polarization dynamics in PbTiO3 thin films is explored using dynamic piezoresponse force microscopy(D-PFM)in conjunction with interferometric displacement *** approach gives rise to 4D data sets containing information on bias-dependent relaxation dynamics at each spatial location without long-range electrostatic *** interpret these data sets in the absence of defined physical models,we employ a non-negative tensor factorization method which clearly presents the data as a product of simple behaviors allowing for direct physics ***,we perform phase-field modeling finding the existence of‘hard’and‘soft’domain wall *** approach can be extended to other multidimensional spectroscopies for which even exploratory data analysis leads to unsatisfactory results due to many components in the decomposition.

关键词： relaxation factorization dynamic

Author Correction:Tensor factorization for elucidating mechanisms of piezoresponse relaxation via dynamic Piezoresponse Force Spectroscopy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

npj Computational Materials 2020年第1期6卷 538-538页

作者： Kyle P.Kelley Linglong Li Yao Ren Yoshitaka Ehara Hiroshi Funakubo Suhas Somnath Stephen Jesse Ye Cao ramakrishnan kannan Rama K.Vasudevan Sergei V.Kalinin Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge USA Department of Physics Tsinghua University Beijing China Department of Materials Science and Engineering University of Texas at Arlington Arlington USA Department of Communications Engineering National Defense Academy Hashirimizu Yokosuka Japan Department of Material Science and Engineering Tokyo Institute of Technology Yokohama Japan National Center for Computational Sciences Oak Ridge National Laboratory Oak Ridge USA Computer Science and Mathematics Division Oak Ridge National Laboratory Oak Ridge USA

The original version of this Article did not acknowledge Rama ***(vasudevanrk@***)as a corresponding *** has now been corrected in both the PDF and HTML versions of the Article.

关键词： HTML relaxation knowledge

Controlling chaos and supressing chimeras in a fractional-order discrete phase-locked loop using impulse control

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 Physics B 2021年第12期30卷 63-73页

作者： Karthikeyan Rajagopal Anitha Karthikeyan Balamurali ramakrishnan Centre for Nonlinear Systems Chennai Institute of TechnologyChennaiIndia Department of Electronics and Communication Engineering Prathyusha Engineering CollegeChennaiIndia

A fractional-order difference equation model of a third-order discrete phase-locked loop(FODPLL) is discussed and the dynamical behavior of the model is demonstrated using bifurcation plots and a basin of attraction. We show a narrow region of loop gain where the FODPLL exhibits quasi-periodic oscillations, which were not identified in the integer-order model. We propose a simple impulse control algorithm to suppress chaos and discuss the effect of the control step. A network of FODPLL oscillators is constructed and investigated for synchronization behavior. We show the existence of chimera states while transiting from an asynchronous to a synchronous state. The same impulse control method is applied to a lattice array of FODPLL, and the chimera states are then synchronized using the impulse control algorithm. We show that the lower control steps can achieve better control over the higher control steps.

关键词： discrete Josephson junction fractional order chaos impulse control chimera

Multiwavelets domain singular value features for image texture classification

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第4期8卷 538-549页

作者： ramakrishnan S. SELVAN S. Department of Information Technology PSG College of Technology Coimbatore 641 004India

A new approach based on multiwavelets transformation and singular value decomposition (SVD) is proposed for the classification of image textures. Lower singular values are truncated based on its energy distribution to classify the textures in the presence of additive white Gaussian noise (AWGN). The proposed approach extracts features such as energy, entropy, local homogeneity and max-min ratio from the selected singular values of multiwavelets transformation coefficients of image textures. The classification was carried out using probabilistic neural network (PNN). Performance of the proposed approach was compared with conventional wavelet domain gray level co-occurrence matrix (GLCM) based features, discrete multiwavelets transformation energy based approach, and HMM based approach. Experimental results showed the superiority of the proposed algorithms when compared with existing algorithms.

关键词： Image texture classification Multiwavelets transformation Probabilistic neural network (PNN)

Optimal Adaptive Genetic Algorithm Based Hybrid Signcryption Algorithm for Information Security

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2015年第5期105卷 47-68页

作者： R.Sujatha M.ramakrishnan N.Duraipandian B.ramakrishnan Velammal Engineering College Anna UniversityIndia School of Computer Applications Madurai Kamarajar UniversityIndia Department of Computer Science and Research Centre S.T.Hindu CollegeMadurai Kamarajar UniversityIndia

The functions of digital signature and public key encryption are simultaneously fulfilled by signcryption,which is a cryptographic *** securely communicate very large messages,the cryptographic primitive called signcryption efficiently implements the same and while most of the public key based systems are suitable for small messages,hybrid encryption(KEM-DEM)provides a competent and practical *** this paper,we develop a hybrid signcryption *** hybrid signcryption is based on the KEM and DEM *** KEM algorithm utilizes the KDF technique to encapsulate the symmetric *** DEM algorithm utilizes the Adaptive Genetic Algorithm based Elliptic curve cryptography algorithm to encrypt the original ***,for the security purpose,we introduce the three games and we proved the attackers fail to find the security attributes of our proposed signcryption *** proposed algorithm is analyzed with Daniel of Service(DOS),Brute Force attack and Man In Middle(MIM)attacks to ensure the secure data transaction.

关键词： Hybrid Signcryption KEM DEM Adaptive Genetic Algorithm EllipticCurve Cryptography

Examining the Factors that Influence the Use of Social Media for Disaster Management by Underserved Communities

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 Disaster Risk Science 2022年第1期13卷 52-65页

作者： Thiagarajan ramakrishnan Louis Ngamassi Shahedur Rahman Accounting Financeand Management Information Systems(MIS)Prairie View A&M UniversityPrairie ViewTX 77446USA

This study examined the propensity of social media use by underserved communities by drawing on the literature on the digital divide and attribution ***,this research explored the factors that can influence the use of social media for disaster *** study used survey methodology to collect data and partial least squares structural equation modeling(PLSSEM)to analyze the data and test the *** results of the study indicate:(1)that the propensity of social media use for disaster management is low for underserved communities;(2)a positive relationship between an individual’s effort and the intention to use social media for disaster management;and(3)a negative relationship between task difficulty and the intention to use social media for disaster *** study expanded the literature on the use of social media in disaster *** article also provides both theoretical and practical implications.

关键词： Attribution theory Digital divide Disaster management Social media use Texas Underserved communities

Robust stability criteria for uncertain linear systems with interval time-varying delay

在线全文

学校读者我要写书评

暂无评论

控制理论与应用（英文版） 2011年第4期9卷 559-566页

作者： Krishnan ramakrishnan Goshaidas RAY Department of Electrical Engineering Indian Institute of Technology Kharagpur

This paper considers the robust delay-dependent stability problem of a class of linear uncertain system with interval time-varying delay and proposes less conservative stability criteria for computing the maximum allowable bound of the delay range. Less conservatism of the proposed stability criteria is attributed to the delay-central point method of stability analysis, wherein the delay interval is partitioned into two subintervals of equal length, and the time derivative of a candidate Lyapunov-Krasovskii functional based on delay decomposition technique is evaluated in each of these delay segments. In deriving the stability conditions in LMI framework, neither model transformations nor bounding techniques using free-weighting matrix variables are employed for dealing the cross-terms that emerge from the time derivative of the Lyapunov-Krasovskii functional; instead, they are dealt using tighter integral inequalities. The proposed analysis subsequently yields a stability condition in convex LMI framework that can be solved using standard numerical packages. For deriving robust stability conditions, two categories of system uncertainties, namely, time-varying structured and polytopic-type uncertainties, are considered. The effectiveness of the proposed stability criteria is validated through standard numerical examples.

关键词： Lyapunov-Krasovskii functional Robust stability Interval time-delay Delay-range-dependent stability Linear matrix inequality

Hydromagnetic flow through uniform channel bounded by porous media

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2011年第7期32卷 837-846页

作者： K.ramakrishnan K.SHAILENDHRA Department of Mathematics Sri Krishna College of Engineering and TechnologySugunapuramKuniamuthurCoimbatore 641008TamilnaduIndia Department of Mathematics Amirta School of EngineeringAmirta Vishwa VidyapeethamCoimbatore 641105TamilnaduIndia

The combined effects of the magnetic field, permeable walls, Darcy velocity, and slip parameter on the steady flow of a fluid in a channel of uniform width are studied. The fluid flowing in the channel is assumed to be homogeneous, incompressible, and Newtonian. Analytical solutions are constructed for the governing equations using Beavers-Joseph slip boundary conditions. Effects of the magnetic field, permeability, Darcy velocity, and slip parameter on the axial velocity, slip velocity, and shear stress are discussed in detail. It is shown that the Hartmann number, Darcy velocity, porous parameter, and slip parameter play a vital role in altering the flow and in turn the shear stress.

关键词： uniform channel permeable wall magnetic field slip velocitY shear stress

Cytoreductive surgery and hyperthermic intraperitonealchemotherapy in gastric cancer

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2016年第3期22卷 1114-1130页

作者： ramakrishnan Ayloor Seshadri Olivier Glehen Department of Surgical Oncology Cancer Institute(WIA)Chennai 600036India Service de Chirurgie Viscérale et Endocrinienne Hospices Civils de LyonCentre Hospitalier Lyon-Sud69495 Pierre-Bénite CedexFrance UniversitéLyon 1 EMR 373869921 OullinsFrance

Gastric cancer associated peritoneal carcinomatosis(GCPC) has a poor prognosis with a median survival of less than one year. Systemic chemotherapy including targeted agents has not been found to significantly increase the survival in GCPC. Since recurrent gastric cancer remains confined to the abdominal cavity in many patients, regional therapies like aggressive cytoreductive surgery( CRS) and hyperthermic intraperitoneal chemotherapy(HIPEC) have been investigated for GCPC. HIPEC has been used for three indications in GC- as an adjuvant therapy after a curative surgery, HIPEC has been shown to improve survival and reduce peritoneal recurrences in many randomised trials in Asian countries; as a definitive treatment in established PC, HIPEC along with CRS is the only therapeutic modality that has resulted in longterm survival in select groups of patients; as a palliative treatment in advanced PC with intractable ascites, HIPEC has been shown to control ascites and reduce the need for frequent paracentesis. While the results of randomised trials of adjuvant HIPEC from western centres are awaited, the role of HIPEC in the treatment of GCPC is still evolving and needs larger studies before it is accepted as a standard of care.

关键词： Gastric cancer Peritoneal carcinomatosis Cytoreductive surgery Hyperthermic intraperitonealchemotherapy

Delay-range-dependent Stability Criterion for Interval Time-delay Systems with Nonlinear Perturbations

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 Automation and computing 2011年第1期8卷 141-146页

作者： K.ramakrishnan G.Ray Department of Electrical Engineering Indian Institute of Technology

In this paper, we consider the problem of robust stability for a class of linear systems with interval time-varying delay under nonlinear perturbations using Lyapunov-Krasovskii （LK） functional approach. By partitioning the delay-interval into two segments of equal length, and evaluating the time-derivative of a candidate LK functional in each segment of the delay-interval, a less conservative delay-dependent stability criterion is developed to compute the maximum allowable bound for the delay-range within which the system under consideration remains asymptotically stable. In addition to the delay-bi-segmentation analysis procedure, the reduction in conservatism of the proposed delay-dependent stability criterion over recently reported results is also attributed to the fact that the time-derivative of the LK functional is bounded tightly using a newly proposed bounding condition without neglecting any useful terms in the delay-dependent stability analysis. The analysis, subsequently, yields a stable condition in convex linear matrix inequality （LMI） framework that can be solved non-conservatively at boundary conditions using standard numerical packages. Furthermore, as the number of decision variables involved in the proposed stability criterion is less, the criterion is computationally more effective. The effectiveness of the proposed stability criterion is validated through some standard numerical examples.

关键词： Lyapunov-Krasovskii (LK) functional delay-range-dependent stability linear matrix inequality (LMI) interval timevarying delay nonlinear perturbations.