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Matter and Radiation at Extremes 2023年第5期8卷 1-18页

作者： Shivani Choudhary De Marco Sudipta Mondal Daniele Margarone subhendu kahaly AFFILIATIONS 1 ELI-ALPS ELI-HU Non-Profit Ltd.Wolfgang Sandner utca 3Szeged 6728Hungary ELI Beamlines Center Institute of PhysicsCzech Academy of SciencesZa Radnicí835252-41 DolníBrezanyCzech Republic Institute of Physics University of SzegedDóm tér 9H-6720 SzegedHungary

A controlled transition between two different ion acceleration mechanisms would pave the way to achieving different ion energies and spectral features within the same experimental set up,depending on the region of *** on numerical simulations conducted over a wide range of experimentally achievable parameter space,reported here is a comprehensive investigation of the different facets of ion acceleration by relativistically intense circularly polarized laser pulses interacting with thin near-critical-density plasma *** results show that the plasma thickness,exponential density gradient,and laser frequency chirp can be controlled to switch the interaction from the transparent operating regime to the opaque one,thereby enabling the choice of a Maxwellian-like ion energy distribution with a cutoff energy in the relativistically transparent regime or a quasi-monoenergetic spectrum in the opaque ***,it is established that a multispecies target configuration can be used effectively for optimal generation of quasi-monoenergetic ion bunches of a desired ***,the feasibility is demonstrated for generating monoenergetic proton beams with energy peak atℰ≈20–40 MeV and a narrow energy spread ofΔℰ/ℰ≈18%–28.6%confined within a divergence angle of∼175 mrad at a reasonable laser peak intensity of I0≃5.4×10^(20)W/cm^(2).

关键词： acceleration regime circular

High-Flux 1ookHz Attosecond Pulse Source Driven by a High-Average Power Annular Laser Beam

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Ultrafast Science 2022年第1期 1-10页

作者： Peng Ye Lenard Gulyas Oldal Tamas Csizmadia Zoltan Filus Timea Grosz Peter Jojart Imre Seres Zsolt Bengery Barnabas Gilicze subhendu kahaly Katalin Varju Balazs Major ELI-ALPS ELI-HU Non Profit LtdWolgang Sandner utca 3Szeged H-6728Hungary Institute of Physics University of SzegedDom ter 9Szeged 6720Hungary Department of Optics and Quantum Electronics University of SzegedDom ter 9Szeged 6720Hungary

High-repetition rate attosecond pulse sources are indispensable tools for time-resolved studies of electron dynamics,such as coincidence spectroscopy and experiments with high demands on statistics or signal-to-noise ratio,especilly in the case of solid and big molecule samples in chemistry and *** with the high-repetition rate lasers,such attosecond pulses in a pump-probe configuration are possible to achieve,until now,only a few such light sources have been ***,by shaping the driving laser to an annular beam,a 100 kHz attosecond pulse train(APT)is reported with the highest energy so far(51 pl/shot)on target(269 pJat generation)among the high-repetition rate systems(>10 kHz)in which the attosecond pulses were temporally *** on-target pulse energy is maximized by reducing the losses from the reflections and filtering of the high harmonics,and an unprecedented 19%transmission rate from the generation point to the target position is *** the same time,the probe beam is also annular and low loss of this beam is reached by using another holey mirror to combine with the *** advantages of using an annular beam to generate attosecond pulses with a high-average power laser are demonstrated experimentally and theoretically,The effect of nonlinear propagation in the generation medium on the annular-beam generation concept is also analyzed in detail.

关键词： annular repetition beam

Secure and resilient improved image steganography using hybrid fuzzy neural network with fuzzy logic

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Journal of Safety Science and Resilience 2024年第1期5卷 91-101页

作者： Sachin Dhawan Hemanta Kumar Bhuyan subhendu Kumar Pani Vinayakumar Ravi Rashmi Gupta Arun Rana Alanoud Al Mazroa Dorset College King George BlvdSurreyBritish ColumbiaCanada Department of Information Technology Vignan’s Foundation for ScienceTechnology and Research(Deemed to be University)Andhra PradeshIndia Krupajal Computer Academy Biju Patnaik University of Technology(BPUT)Rourkela 751002India Center for Artificial Intelligence Prince Mohammad Bin Fahd UniversityKhobarSaudi Arabia NSUT East Campus(Formerly AIACTRDelhi 110031India(Affiliated to Guru Gobind Singh Inderaprastha University))Dwarka 110078India Department of Computer Science and Engineering Galgotias College of Engineering and Technology Greater Noida 201310Uttar PradeshIndia Department of Information Systems College of Computer and Information SciencesPrincess Nourah bint Abdulrahman University(PNU)P.O.Box 84428Riyadh 11671Saudi Arabia

The exponential growth in communication networks,data technology,advanced libraries,and mainly World Wide Web services has played a pivotal role in facilitating the retrieval of various types of information as ***,this progress has also led to security concerns related to the transmission of confidential ***,safeguarding these data during communication through insecure channels is crucial for obvious *** emergence of steganography offers a robust approach to concealing confidential information,such as images,audio tracks,text files,and video files,in suitable media carriers.A novel technique is envisioned based on back-propagation *** to the proposed method,a hybrid fuzzy neural network(HFNN)is applied to the output obtained from the least significant bit substitution of secret data using pixel value dif-ferences and exploiting the modification *** simulation and test results,it has been observed that the proposed methodology achieves secure steganography and superior visual *** the experiments,we observed that for the secret image of the cameraman,the PSNR&MSE values of the proposed technique are 61.963895 and 0.041361,respectively.

关键词： Image enhancement Image processing Steganography Deep learning Fuzzy neural combination

Influence of land cover features on avian community and potential conservation priority areas for biodiversity at a Ramsar site in India

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Ecological Processes 2022年第1期11卷 345-359页

作者： Souvik Barik Goutam Kumar Saha subhendu Mazumdar Department of Zoology University of Calcutta35Ballygunge Circular RoadKolkata 700019India Department of Zoology Shibpur Dinobundhoo Institution(College)ShibpurHowrahIndia

Background:Wetlands provide diverse ecological services to sustain rich biodiversity,but they are recklessly exploited around the *** Kolkata Wetlands(EKW;Ramsar site No.1208,~125 km^(2))was once very rich in faunal diversity that declined over the years due to various anthropogenic *** such scenarios,effective management plans need to contemplate local and landscape level initiatives and prioritize areas for *** the foraging guild structure and spatial patterns of relationship between bird and its environment provides important insight of ecological processes of ***,we carried out extensive surveys in 142 point count stations to explore the diversity and foraging guild structure of birds in *** addressed two important questions that how bird diversity varied from the outer periphery of the city towards the wetlands and how bird diversity is influenced by land cover features at local and landscape level in wetland *** goal of this study was to prepare a spatial map of avian diversity and to find the conservation priority areas for birds in this internationally recognized wetland ***:We recorded 94 species of birds and the Shannon diversity index values ranged between 1.249 and *** found that the avian diversity increased with increasing distance from city *** and insectivores were the dominant foraging guilds,followed by carnivores,granivores,frugivores and *** Linear Models revealed that bird communities were positively influenced by areas of wetlands,dikes and banks,agricultural field and emergent vegetation,and negatively influenced by built-up *** the projected spatial map of species diversity,74.15 km^(2)area has high ***,we identified 12.82 km^(2) of top 10%conservation priority ***:Low bird diversity near city periphery is related to habitat degradation due to anthropogenic *** of omnivores and insectivores

关键词： Bird diversity Spatial mapping FRAGSTATS ZONATION Wetland management East Kolkata Wetlands

Compositional analysis in the nano-regime: A SIMS perspe ctive

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原子与分子物理学报 2005年第3期22卷 393-399页

作者： subhendu Sarkar Purushottam Chakraborty Surface Physics Division Saha Institute of Nuclear Physics 1/AF Bidhannagar Kolkata 700 064IndiaSurface Physics Division Saha Institute of Nuclear Physics 1/AF Bidhannagar Kolkata 700 064India

A serious problem in secondary ion mass spectrometry (SI MS ) analysis is its “matrix effect” that hinders the quantification of a certain species in a sample and consequently, appropriate corrective measures are taken to calibrate the secondary ion currents into respective concentrations for accu rate compositional analysis. Use of “calibration standards” is necessary for t his purpose. Detection of molecular MCs_n+ ions (M-element to be analyz ed , n=1, 2, 3,….) under Cs+ ion bombardment is a possible mean to minimiz e such matrix effect, enabling one to quantify without the need of calibration sta ndards. Our recent studies on MCs_n+ molecular ions aim towards the understanding of their formation mechanisms, which are important to know their e ffects on SIMS quantification. In-depth quantitative analysis is a major strength of SIMS for which ‘depth resolution’ is of significant relevance. The optimal choice of the impact pa rameters during SIMS analyses can play an effective role in obtaining data with ultra-high depth resolution. SIMS is possible at depth resolution in the nm or even sub-nm rang e, with quantifiable data obtained from the top monolayer onwards into the material. Wi th optimized experimental conditions, like extremely low beam current (down to ～10 nA), and low bombarding energy (below 1 keV), ultra-high depth resolution SIMS has e nabled interfacial composition analysis of ultra-thin films, quantum wells, heterostru ctures, etc. and complex low-dimensional structures with high precision and re peatability.

关键词： SIMS 次级离子质谱离子光谱测定法

SYNCHRONIZATION IN A RING OF UNIDIRECTIONALLY COUPLED FITZHUGH-NAGUMO NEURONS

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International Journal of Biomathematics 2014年第1期7卷 161-171页

作者： ANINDITA BHATTACHARJEE M. K. DAS subhendu GHOSH Galgotia Institute of Management and Technology Greater Noida UP 201306 India Institute of Informatics and Communication University of Delhi South CampusBenito-Juarez Road New Delhi 110021 India Department of Biophysics University of Delhi South Campus Benito-Juarez Road New Delhi 110021 India

Synchronization behavior of an ensemble of unidirectionally coupled neurons with a constant input is investigated. Chemical synapses are considered for coupling. Each neuron is also considered to be exposed to a self-delayed feedback. The synchronization phenomenon is analyzed by the error dynamics of the response trajectories of the system. The effect of various model parameters e.g. coupling strength, feedback gain and time delay, on synchronization is also investigated and a measure of synchrony is computed in each cases. It is shown that the synchronization is not only achieved by increasing the coupling strength, the system also required to have a suitable feedback gain and time delay for synchrony. Robustness of the parameters for synchrony is verified for larger systems.

关键词：单向耦合同步性神经元环形延迟反馈耦合强度反馈增益动力学分析

Design for manufacturability and reliability in extreme-scaling VLSI

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Science China(Information Sciences) 2016年第6期59卷 96-118页

作者： Bei YU Xiaoqing XU subhendu ROY Yibo LIN Jiaojiao OU David Z.PAN CSE Department The Chinese University of Hong Kong ECE Department University of Texas at Austin Cadence Design Systems Inc.

In the last five decades, the number of transistors on a chip has increased exponentially in accordance with the Moore’s law, and the semiconductor industry has followed this law as long-term planning and targeting for research and development. However, as the transistor feature size is further shrunk to sub-14 nm nanometer regime, modern integrated circuit(IC) designs are challenged by exacerbated manufacturability and reliability issues. To overcome these grand challenges, full-chip modeling and physical design tools are imperative to achieve high manufacturability and reliability. In this paper, we will discuss some key process technology and VLSI design co-optimization issues in nanometer VLSI.

关键词： design for manufacturability design for reliability VLSI CAD

Elastic Waves in Composite Media and Structures: With Applications to Ultrasonic Nondestructive Evaluation 1st

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Multigrid One-Shot Method for PDE-Constrained Optimization Problems

丛书名： Mechanical engineering series

2009年

作者： subhendu K. Datta Arvind H. Shah

来源：畅想之星图书光盘版（南... 评论

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Applied Mathematics 2012年第10期3卷 1565-1571页

作者： subhendu Bikash Hazra Group of Water Supply and Groundwater Protection Institute IWAR Department of Civil Engineering and Geodesy Technical University of Darmstadt Darmstadt Germany

This paper presents a numerical method for PDE-constrained optimization problems. These problems arise in many fields of science and engineering including those dealing with real applications. The physical problem is modeled by partial differential equations (PDEs) and involve optimization of some quantity. The PDEs are in most cases nonlinear and solved using numerical methods. Since such numerical solutions are being used routinely, the recent trend has been to develop numerical methods and algorithms so that the optimization problems can be solved numerically as well using the same PDE-solver. We present here one such numerical method which is based on simultaneous pseudo-time stepping. The efficiency of the method is increased with the help of a multigrid strategy. Application example is included for an aerodynamic shape optimization problem.

关键词： Shape Optimization Simultaneous Pseudo-Time Stepping Multigrid Methods Preconditioner Reduced SQP Methods Reduced Hessian One-Shot Method Airfoil

Use of sewage in split doses to enhance water productivity for fish culture

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Aquaculture and Fisheries 2021年第6期6卷 609-616页

作者： Rathindranath Mandal Arabinda Das Debnarayan Chattopadhyay Ajmal Hussan subhendu Adhikari Baidyanath Paul Farhana Hoque Parthapratim Chakrabarti Bindu R.Pillai Regional Research Centre ICAR-Central Institute of Freshwater AquacultureRaharaKolkata700118West BengalIndia ICAR-Central Institute of Freshwater Aquaculture Bhubaneswar751002OdishaIndia

The problem of sewage disposal has received great attention *** raw sewage contains a variety of high inorganic and organic matters that affect natural water *** mitigate such problem,sewage may be recycled through aquaculture *** recycling in aquaculture enhances water productivity through nutrients *** loading of sewage ensures viable aquaculture;otherwise,fish mortality occurs due to poor water *** optimize sewage application,two different experiments were conducted,each with four *** both experiments,three fish species namely rohu(Labeo rohita Hamilton,1822),mrigal(Cirrhinus mrigala Hamilton,1822),and bata(Labeo bata Hamilton,1822)were tested in triplicate in FRP(Fibre-Reinforced Plastic)*** sewage concentrations(0,25%,50%and 75%)used in first experiment were prepared by mixing freshwater,showing Biochemical Oxygen Demand(BOD)2.0±0.4 mg/L,10.8±1.4 mg/L,19.6±1.5 mg/L and 41.6±2.58 mg/L,*** 30 days rearing,results showed≥75%fish survival in sewage concentrations up to 50%with BOD level 19.6±1.5 mg/*** than 50%fish survived in 75%sewage concentration,with BOD level as 41.6±2.58 mg/*** second experiment was conducted for 90 days considering 50%sewage concentration as basal dose with BOD level as 19.6 mg/L as an acceptable limit for fish *** doses of sewage were applied in T_(1),T_(2) and T_(3) treatments fortnightly,weekly and semi-weekly intervals,while single dose was used in C(control)*** of split doses resulted better hydro-biological changes,including nutrients recovery,in T_(1),T_(2) and T_(3) than that of single dose in *** growth plotted with net primary productivity(NPP),phytoplankton and zooplankton densities exhibited positive correlations in T_(2)(12 doses)and T_(3)(24 doses),considered as optimal doses to ensure better water productivity for desirable fish production than sewage with single dose or limited doses(6 doses).

关键词： Sewage Split dose Water productivity Fish rearing