Journal of Computational Electronics

Article	Citations
Comparative of analog performance of transcapacitances in asymmetric self-cascode and graded-channel SOI nMOSFETs	108
Impact of geometrical parameters on AlGaN/GaN heterostructure MOS-HEMT biosensor	91
Band structure of molybdenum disulfide: from first principle to analytical band model	84
Realization of fractal resonator cells developed on substrate-integrated waveguide for S-band filter applications	58
Tunable optical filter with high performance based on 2D photonic crystal	53
Stress-induced transformation on the cubic perovskite RbTaO3 for high-temperature applications: a DFT approach	48
Electric field-tuned spin Seebeck effect in doped SiC nanoribbons	43
A microcontroller-based signal conditioning circuitry for acetone concentration detection using a metal oxide-based gas sensor	42
Predicting model of I–V characteristics of quantum-confined GaAs nanotube: a machine learning and DFT-based combined framework	41
Three-dimensional quantum-corrected Monte Carlo device simulator of n-FinFETs	30
Designing a double-negative metamaterial photonic crystal using the Thue–Morse sequence	28
CsInTiS4 quantum dots as a next-generation material: bridging ceramics and semiconductors for sustainable nanotechnology	28
Theoretical calculations of the optoelectronic properties of a penta-graphene monolayer: study of many-body effects	27
Ultrawideband Lu chaotic surface-based microwave absorber design for stealth applications	27
Numerical investigation of energy level strategy for TMO/Si tunneling heterojunction solar cells	26
Power-delay-product optimal repeater design for horizontal and vertical multilayer graphene nanoribbon interconnects	26
Susceptibility, entropy and specific heat of quantum rings in monolayer graphene: comparison between different entropy formalisms	24
Comparative modal analysis in micro–nano-optical fiber tapers using spectral parameter power series method and exact modes method	24
Size and shape effects on effective mass, electronic and optical properties of V-shaped quantum dot: influence of an off-center donor atom, hydrostatic pressure and temperature	23
Supercontinuum spectra above 2700 nm in circular lattice photonic crystal fiber infiltrated chloroform with the low peak power	23
Impact of in-plane electric field on the optical properties of CO2 adsorbed 2D MoSe2 monolayer: application as a photodetector	21
Research on explosive electromagnetic field interference analysis based on field-circuit cooperated modeling and simulation	20
Light-based detection of aquatic algae using one-dimensional photonic crystals	20
Electrical parameter computation of various photovoltaic models using an enhanced jumping spider optimization with chaotic drifts	18
Design and implementation of a fractal microstrip patch array for vehicle-to-vehicle communication using meta-heuristic techniques	18

ANN-based estimation of dispersion characteristics of slotted photonic crystal waveguides	18
Characterization of integrated nanomaterials using deep learning method-based Mantis search algorithm	17
Modelling and simulation of plasma-assisted 2D graphene based solar cells	17
Numerical analysis of lossy nonuniform interconnect lines in modern integrated circuits by multistep θ-method and Runge-midpoint method	17
Study on single-event radiation effects and hardening techniques in GaN HEMTs	16
Design-driven efficiency enhancement of CdTe1−xSex solar cells via interface band alignment and optimization	16
Wave attenuation based on Beer-Lambert law in SiO2/ZrO2, TiO2/MgF2, Si/Al2O3 and Nb2O5/CYTOP one-dimensional photonic crystals	16
Current and voltage characteristics of a thermoelectric couple	15
Pragmatic evaluation of fin height and fin width combined variation impact on the performance of junctionless transistors	14
High data rate 4x2 photonic crystal encoder using irregular hexagon ring resonator	14
Electronic and thermoelectric properties of group IV–VI van der Waals heterostructures	14
Optimization of the heat conduction process in a double-gate MOSFET using an enhanced electrothermal model	14
Modeling of effective mobility in 3D NAND flash memory with polycrystalline silicon channel	14
Enhancing the design and performance of a gate-all-around (GAA) charge plasma nanowire field-effect transistor with the help of the negative-capacitance technique	14
Bandstructure and quantum transport properties of AGNR unit cells with V-shaped edge patterning	14
NEGF-based investigation of electrically doped few layer MoTe2 H2 gas sensor	14
Correction to: Terahertz rectangular waveguides with insereted graphene films biased by light and their quasi-linear electromagneroc modeling	13
Electronic, transport and ballistic device properties of quasi-one-dimensional GeS	13
Design and performance improvement of silver-gallium sulfide-TDMC heterostructure-based surface plasmon resonance nano biosensor for detection of fat in milk	13
Simulation of a supercapciator device and its properties based on graphene/hBN electrode material and KCl as an electrolyte	13
Intersubband optical absorption in (In,Ga)N/GaN double quantum wells considering applied electric field effects	12
Configuring a reversible full adder using the Pockels electro-optic effect of a Ti:LiNbO$$_3$$-based MZI	12
Revealing structural, elastic, optoelectronic and thermoelectric properties of lead-free Ba2XTiO6 (X = Hf, Ce, Te) double perovskite for solar cells applications	12
An approach on mathematical modeling of PV module with sensitivity analysis: a case study	12
Device simulation of GeSe homojunction and vdW GeSe/GeTe heterojunction TFETs for high-performance application	12
Analyzing the operational versatility of advanced IBC solar cells at different temperatures and also with variation in minority carrier lifetimes	12
Efficient in-depth analysis and optimum design parameter estimation of MEMS capacitive pressure sensor utilizing analytical approach for square diaphragm	12
Correction to: Microwave coplanar band-stop filters based on electric-LC resonators: systematic numerical approach and experimental validation	12
Correction to: On a superalgebraically converging, numerically stable solving strategy for electromagnetic scattering by impedance cylinders	11
Correction to: Analyzing the effect of dynamic properties of materials and operating medium on sensor parameters to increase the performance of diaphragm-based static/dynamic pressure sensors	11
Strain engineered < Si/Si0.97C0.03 > superlattice photodetector for optoelectronic applications: a comprehensive numerical analysis and experimental verification	11
Optoelectronic properties of monolayer and bilayer AgI: role of many-body interactions	11
Study of chalcogenide-based metal perovskites BaZrX3 (X = S and Se): DFT insight into fundamental properties for sustainable energy generation using AMPS-1D	11
Optimization of CdS-free non-toxic electron transport layer for Sb2S3-based solar cell with notable enhanced performance	11
Emerging tunnel FET and spintronics-based hardware-secure circuit design with ultra-low energy consumption	10
Optimized dielectric-plasmonic interfaces for long-range surface plasmon resonance sensors	10
Empirical mathematical model based on optimized parameter extraction from captured electrohydrodynamic inkjet memristor device with LTspice model	10
Enhanced single-diode model parameter extraction method for photovoltaic cells and modules based on integrating genetic algorithm, particle swarm optimization, and comparative objective functions	10
Polarization-insensitive large-scanning-angle broadband-stop frequency-selective surface for electromagnetic shielding	10
Parameter estimation of three-diode solar photovoltaic model using an Improved-African Vultures optimization algorithm with Newton–Raphson method	10
Exploring the electronic and thermoelectric properties of zigzag and armchair edge Irida-Graphene nanoribbons	10
Multiwavelength plasmonic activity in aluminum-based 2D nanostructures for biosensing applications	10
An efficient and flexible window function for a memristor model and its analog circuit application	10
Recursive Green’s functions optimized for atomistic modelling of large superlattice-based devices	10
Designing a novel MPPT algorithm based on the extraterrestrial irradiance for photovoltaic energy generation systems and testing under partial shade conditions	10
Technical review of four different quantum systems: comparative analysis of quantum correlation, signal-to-noise ratio, and fidelity	9
A conformal miniaturized frequency selective surface with high angular stability for EMI shielding in 5G n258 band applications	9
New trends in the hydrogen energy storage potentials of (8, 8) SWCNT and SWBNNT using optical adsorption spectra analysis: a DFT study	9
A physics-based analytical model for single-event transients in an InGaAs n-channel FinFET suitable for circuit simulations	9
Heterojunction active layer MAPbI3/CsPbI3 design for high-performance perovskite solar cells: a computational analysis achieving 20.5% efficiency	9

Polarization-selective dual-mode metasurface for transmission, reflection, and absorption	9
Design and FEM analysis of split electrode SAW sensor for volatile organic compound gases based on CNT/MoS2 composite for biomarker applications	9
Enhanced performance of thin-film amorphous silicon (a-Si) solar cells encapsulated with distributed Bragg reflector pairs	9
Design of a novel memtranstor emulator using CCIIs and experimental validation	9
GRCircuit: functional macro blocks circuit recovery tool	9
A theoretical analysis to improve the tuning and sensitivity of a surface plasmon resonance biosensor employing titanium disilicide–graphene heterostructures	8
Low power memristive gas sensor architectures with improved sensing accuracy	8
Demonstration of dipole-induced transparency using mirrored split-ring resonator metasurface for microwave applications	8
Novel circuit design for reversible multilayer ALU in QCA technology	8
A multi-objective genetic algorithm approach applied to compact meander branch line couplers design for 5G-enabled IoT applications	8
Efficient and reliable hybrid MTJ/CMOS-based logic-in-memory architecture using SHE-MTJ	8
Precise control of single-phenanthrene junction’s conductance	8
Computational optimization and optical analysis of thin-film organic solar cells for high efficiency	8
A comprehensive density-of-states model for oxide semiconductor thin film transistors	8
Lead-free, stable, mixed SnGe perovskites for light to electricity conversion applications in indoor and space conditions	8
Modeling and simulation of a GaAs/AlGaAs quantum well photodetector for terahertz application	8
Optical properties and its atomistic doping manipulation of two-dimensional Janus MoSTe photodetectors	8
Novel junctionless GAA negative capacitance FET based on gate engineering aspects: analytical modeling and performance assessment	7
A hybrid artificial intelligence framework for predicting electrical and thermal properties of graphene nanoplatelet-enhanced nanoelectronic materials	7
Numerical study of high-efficiency CIGS solar cells by inserting a BSF µc-Si:H layer	7
Combined effect of Stone–Wales defects and titanium doping on electronic properties of a silicon carbide monolayer: DFT	7
ANFIS-based impedance analysis of an infinite array of rectangular microstrip antennas	7
Cutting-edge dyes for p-type dye-sensitized solar cells: a theoretical study of 1,8-naphthalene imide derivatives	7
Triple-band perovskite based chiral metasurface biosensor with multi-functionalities	7
Multi-scale simulations of two dimensional material based devices: the NanoTCAD ViDES suite	7
Special issue on ab initio simulations of electron and phonon transport in nanostructures	7
Modeling and performance analysis of high-k gate material-based isfet biosensors using TCAD	7
Role of metal–semiconductor contacts on the performance of $$\hbox {MoS}_2$$ field-effect transistor: an atomistic study	7
A simple approach for integrating quantum confinement effects into TCAD simulations of tunnel field-effect transistors	7
Investigation of stability parameters of a gate-stack junctionless double-gate transistor (GS-JLDGT)-based 6T and 3T SRAM in the presence of traps	7
TCAD analysis of single-event burnout caused by heavy ions for a GaN HEMT	7
Normal electromagnetic flux surfaces with the existence of the visco-modified effect	7
Simulations of RF wave-induced modulation of filament growth and bipolar resistive switching in conductive bridging RAM	7
Laser interaction with a MIM nanostructure including bowtie aperture and cylindrical holes for plasmonic field enhancement based on strong coupling of LSPR and SPPs	7
Investigation on the variation effect of gate work function on $$N^+$$ pocket-doped junctionless vertical tunneling FETs	6
A nanoelectromechanical energy-reversible switch: theoretical study and verification by experiment of its applicability to adiabatic computing	6
Exploration of the effect of different terminal acceptors to improve the efficacy of pyrrolopyrazine-based compounds for organic solar cells: a quantum chemical approach	6
A physics-based electrical model of a magnetically sensitive AlGaN/GaN HEMT	6
The optimization of design and performance in hybrid organic/inorganic LEDs toward next-generation high-efficiency LEDs: application of multi-model hybrid machine learning approach	6
Optimization and performance enhancement in PBDB-T:ITIC-based organic photodetector via SWCNT integration	6
An extensive sensitivity analysis of graphene channel Z-shaped TFET for hydrogen sensing	6
Correction: Electrothermal properties of 2D materials in device applications	6
Performance assessment of a GaSb/Si based dual material stacked double-gate hetrojunction TFET for label free biosensing applications	6
Modeling and analysis of gate-induced drain leakage current in negative capacitance junctionless FinFET	6
Compact drain current model of a double-gate raised buried oxide TFET for integrated circuit application	6
Theoretical study of electronic and optical properties in doped quantum structures with Razavy confining potential: effects of external fields	6
Electronic transport behavior of 4,6-bis(4-nitrophenyl)-2-phenyl-3,5-diaza-bicyclo[3.1.0]hex-2-ene (a bicyclic aziridine) as optical molecular switch: a first-principles approach	6
Thermally compensated ZnO film bulk acoustic resonator for RF application above 5GHz frequency	6
Theoretical analysis of relative intensity noise in semiconductor QD lasers	6
Exploring a reversible NOR from a 4 × 4 modified Fredkin gate and its optical mapping using a LiNbO3-based MZI	6
Estimating equivalent circuit parameters in various photovoltaic models and modules using the dingo optimization algorithm	6
Effect of interlayer spacing on the electronic and optical properties of SnS2/graphene/SnS2 sandwich heterostructure: a density functional theory study	6
Computer simulation and performance analysis of metal–semiconductor–metal back-contact perovskite solar cells	6
Properties of cubic GdAlO3 perovskite under pressure: density functional theory and Monte Carlo simulations	6
IFT and Chebyshev-based planar array thinning for adaptive interference suppression	6
Physical analysis of β-Ga2O3 gate-all-around nanowire junctionless transistors: short-channel effects and temperature dependence	6
Gated-anode diodes for RF and microwave rectifiers for WPT applications: a simulation study on DC and RF characteristics	5
A novel design for an ultracompact optical majority gate based on a ring resonator on photonic crystal substrate	5
Engineering the light absorption spectrum and electronic properties of black and blue phases of a SiSe monolayer via biaxial straining	5
Absorption coefficient of a DMS ellipsoid quantum dot with Rashba spin–orbit interaction	5
Magnetic and magnetocaloric properties of a C20 fullerene structure: Monte Carlo study	5
Nonlinear and dispersive effects on dark soliton interaction in photonic crystal fiber	5
Breather-like soliton, M-shaped profile, W-shaped profile, and modulation instability conducted by self-frequency shift of the nonlinear Schrödinger equation	5
High-order accurate numerical simulation of monochromatic waves in photonic crystal ring resonators with the help of a non-iterative domain decomposition	5
Next-generation high-performance complex optical sequential circuits: an electro-optic modulation in GaAlAs directional couplers	5
Numerical modeling of a dielectric modulated surrounding-triple-gate germanium-source MOSFET (DM-STGGS-MOSFET)-based biosensor	5
Low-frequency noise performance of a molybdenum ditelluride double-gate MOSFET	5
A novel micro-scaled multi-layered optical stress sensor for force sensing	5
Hetero-gate dielectric SiGe/Si tunnel FET: a hydrogen gas sensor with improved sensitivity	5
Nonlinear dynamics of a Josephson junction coupled to a diode and a negative conductance	5
Nonlocalization of singular potentials in quantum dynamics	5
Exploring dielectric relaxation and AC conductivity of layered double hydroxides	5
Geometric shape’s impact on core-shell nanocomposites’ optical properties	5
Developing a hybrid single band carrier transport model for (Al,Ga)N heterostructures	5
Floating/grounded charged controlled memristor emulator using DVCCTA	5
Investigating the effect of structural modifications on the performance of transistors based on black phosphorene nanoribbons	5
An efficient technique to predict DC characteristics of nano-FinFETs using a deep neural network	5
Full charge incorporation in ab initio simulations of two-dimensional semiconductor-based devices	4
The energy-loss tensor in the bilayer and monolayer graphene: the role of many-body effects	4
Combinational logic circuits based on a power- and area-efficient memristor with low variability	4

Optical Characteristics of MoTe2, MoTe2/MoSe2, and MoTe2/WSe2 DGMOSFETs	4
Fast approximate solutions for solar cell I–V characteristics using resistance–diode circuits: bridging circuit theory and photovoltaics	4
Research on high sensitivity fano resonance sensing based on MIM waveguide coupled with double Fibonacci spirals	4
Effects of passivation type on electrical transport of a defect-engineered graphene nanoribbon FET	4
Gazeau-Klauder coherent states for a harmonic position-dependent mass	4
Sensitivity enhancement of a graphene, zinc sulfide-based surface plasmon resonance biosensor with an Ag metal configuration in the visible region	4
AI-powered deep ultraviolet laser diode design for resource-efficient optimization	4
Performance analysis of CsPbI3-based solar cells under light emitting diode illumination as an energy harvester for IoT and indoor photovoltaics	4
An ultra-fast and precise automatic design framework for predicting and constructing high-performance shallow-trench-isolation LDMOS devices	4
Influence of pressure and composition on electronic properties, phonon frequencies, and sound velocity for the zinc-blende GaAs1-xNx alloy	4
Realization of energy efficient GF Xtime multiplier using quantum dot cellular automata (QCA) for AES-MixColumn	4
Ultrahigh FOM and multiple Fano resonances in MIM waveguide systems with half-ring and rectangular cavities	4
Comparative study for effect of Ti, Nb and W incorporation on the electronic and optical properties of pristine hafnia (m-HfO2): DFT theoretical prospective	4
A review of structural and electronic properties of graphyne-based nanotubes	4
Analog performance and linearity analysis of a p-type group IV-IV SiGe TFET	4
Master equations for Wigner functions with spontaneous collapse and their relation to thermodynamic irreversibility	4
Selective filter using Thue–Morse structures by the finite element and transfer matrix methods	4
A novel design of graphene field-effect transistor-based out-phasing power amplifier	4
Realization of elementary reversible BVF gate and reversible full adder using optical ring resonators	4
Electrothermal properties of 2D materials in device applications	4
IonMonger 2.0: software for free, fast and versatile simulation of current, voltage and impedance response of planar perovskite solar cells	4
Rapid time-domain simulation of fractional capacitors with SPICE	4
An automatic routing approach for NML circuits	4
6G Rotman lens D-band beam-steering microstrip antenna	4
Performance analysis of Cu/CNT-based TSV: impact on crosstalk and power	4
A transient thermal analysis applied on hybrid aluminum and carbon nanotubes interconnects using a new finite difference algorithm	4
Quantum energy-transport and drift-diffusion models for electron transport in graphene: an approach by the wigner function	4
A high-performance doping-less tunnel FET with pocketed architecture: proposal and analysis	4
Matched coordinate technique in the analysis of self-assembled cylinders	4
DFTBephy: A DFTB-based approach for electron–phonon coupling calculations	4
Electronic structures and stability of double-walled armchair (n,n)@(m,m) SiC nanotubes	4
Comparative study of multi-physics generated small dipoles in conducting media	3
An improved design based on a symmetrical toggle shunt capacitive RF-MEMS switch with multiple stable states and Off-state frequency tunability	3
A piezoelectric sensor with high accuracy and reduced measurement error	3
A feasibility study of microwave UAV imaging based on multi-station polarimetric radars	3
Design and simulation of an optical Feynman gate based on a 2D photonic crystal structure	3
Hydrogen detector in Kretschmann configuration based on an inorganic perovskite	3
Special issue on Wigner functions in computational electronics and photonics	3
Analytical modeling and simulation of lattice-matched Ferro PZT AlGaN/GaN MOSHEMT for high-power and RF/Microwave applications	3
Steady-state computational analysis of a partially shaded photovoltaic system	3
Human body cholesterol detection based on a photonic crystal fiber sensor within a hollow octagonal core configuration	3
Ultrahigh on/off-current ratio γ-graphyne-1 nanotube-based sub-10-nm TFET modeling and simulation	3
Electrochemical impedance spectroscopy technique-based internal parameter estimation of a monocrystalline PV cell	3
Analyzing the impact of drain-engineered DG GNR-TFET on analog/RF performance metrics	3
Compact model for MFIS-NCFETs considering deep-level interface trap states	3
Terahertz conductivity of monolayer MoS$$_2$$	3
Systematic analysis of semiconductor photoconductivity dynamics under different laser excitations: two- and three-level models	3
Impact of alloying on the bandgap energy in nano-sized ternary semiconducting compounds	3
Investigating the role of structural parameters of gold thin film nanohole arrays on the plasmonic phenomenon of extraordinary optical transmission	3
Molecular modeling and simulation for the design of dye sensitizers with mono- and di-substituted donor moieties	3
Parallel approach of Schrödinger-based quantum corrections for ultrascaled semiconductor devices	3
Thermodynamically consistent stabilization of the drift-diffusion model for arbitrary band structures and carrier statistics	3
Modeling and design of a Mott selector for a ReRAM-based non-volatile memory cell in a crossbar architecture	3
Gate-stack optimization of a vertically stacked nanosheet FET for digital/analog/RF applications	3
Scattering characteristics of metal circular wire gratings in microwave and terahertz ranges	3
PtSe2 and black phosphorus employed for sensitivity improvement in the surface plasmon resonance sensor	3
A Godunov-type stabilization scheme for the Boltzmann transport equation of III-V devices with a 3D k-space	3
Feasibility of a 9 THz HgTe/HgCdTe quantum-well vertical-cavity surface-emitting laser	3
Computational modeling and analysis of a chemical gas sensor utilizing WO3 thin films for NO2 detection	3
A new fault-tolerance majority voter circuit for quantum-based nano-scale digital systems	3
Adolescent identity search algorithm for parameter extraction in photovoltaic solar cells and modules	3
Electronic structure, elastic and magnetic properties of the binary intermetallics RFe2 (R = Eu, Gd and Tb)	3
Numerical analysis of emerging concept of perovskite/silicon heterojunction solar cells	3
Modelling and analysis of a negative capacitance junctionless FinFET with ferroelectric spacer: a paradigm shift in low power electronics	3
Correction: Revealing structural, elastic, optoelectronic and thermoelectric properties of lead-free Ba2XTiO6 (X = Hf, Ce, Te) double perovskite for solar cells applications	3
Analysis of optical and electrical properties of graphene field effect transistors for radiation detection	3
Driftfusion: an open source code for simulating ordered semiconductor devices with mixed ionic-electronic conducting materials in one dimension	3
Small-signal non-quasi-static model of a multi-fin FinFET for analog and linearity analysis: the role of gate resistance	3
Numerical aspects of a Godunov-type stabilization scheme for the Boltzmann transport equation	3
Transition metal induced-magnetization in zigzag SiCNTs	3
A model to determine variation in dielectric constant with size and composition in semiconducting nanosolids	3
Simple and efficient estimation of I–V photovoltaic using nonlinear curve fitting equivalent circuit model in Lambert W function form	3
Study of the ISO-FDTD algorithm for processing higher-order dielectric function in SF-FDTD	3
Analysis and codesign of electronic–photonic integrated circuit hardware accelerator for machine learning application	3
Simultaneous detection of ague stages by using a multi-inner channel photonic crystal fiber based surface plasmon resonance sensor	3
Analysis of dipyridine dipyrrole based molecules for solar cell application using computational approach	3
Plasma-assisted carbon nanotube for solar cell application	3
A performance evaluation of a novel field-effect device as an alternative to the field-effect diode	3
Effect of filament regimes in the resistive switching behavior of oxide-based complementary memristor	3
Design and modeling of multi-color absorber based on periodic van der Waals heterostructures including TMDCs	3
Correction: On injection in intrinsic single‑carrier devices	3
Resistance saturation in semi-conducting polyacetylene molecular wires	2
Theoretical simulation of a-Si:H-based p–i–n ultrathin-film solar cell using ZnO as a back reflector layer (BRL) via SCAPS-1D	2
Exploring optimal pyramid textures using machine learning for high-performance solar cell production	2
Investigation of structural and conformational stability, electronic transition, NLO, FMO, and DSSC parameters of trans-dichloro-nitro chalcone isomers: a DFT insight	2
On efficient modeling of drain current for designing high-power GaN HEMT-based circuits	2
Optimizing bend loss in optical waveguide channel routing on photonic integrated circuits	2
A novel hybrid design methodology for EBG structures with application to mutual coupling reduction in antenna arrays	2
Two-band model of T-graphene	2
Neurobiological transition of magnetized and demagnetized dynamism for fractional Hindmarsh–Rose neuron model via fractal numerical simulations	2
Generation of a multi-scroll chaotic system via smooth state transformation	2
Outstanding tunable electrical and optical characteristics in monolayer silicene at high terahertz frequencies	2
A deterministic Wigner transport equation solver with infinite correlation length	2
A DFT investigation of Sc-based perovskite-type hydrides XScH3 (X = K, Na) for hydrogen storage application	2
Hamiltonian deep neural network optimized with pelican optimization algorithm-fostered substrate-integrated waveguide antenna design for 5G	2