Strong Converse Using Change of Measure Arguments

The strong converse for a coding theorem shows that the optimal asymptotic rate possible with vanishing error cannot be improved by allowing a fixed error. Building on a method introduced by Gu and Effros for centralized coding problems, we develop a general and simple recipe for proving strong converse that is applicable for distributed problems as well. Heuristically, our proof of strong converse mimics the standard steps for proving a weak converse, except that we apply those steps to a modified distribution obtained by conditioning the original distribution on the event that no error occurs. A key component of our recipe is the replacement of the hard Markov constraints implied by the distributed nature of the problem with a soft information cost using a variational formula introduced by Oohama. We illustrate our method by providing a short proof of the strong converse for the Wyner-Ziv problem and strong converse theorems for interactive function computation, common randomness and secret key agreement, and the wiretap channel; the latter three strong converse problems were open prior to this work

Investigation of Recessed Junctionless Double Gate MOSFET for Radio Frequency Applications

Junctionless Metal Oxide Semiconductor Field-Effect Transistor (JL MOSFET) is one of the promising candidate to replace the junction based MOSFET for upcoming technology nodes. Semiconductor industries are continuously urging for large ON current with the low OFF current and low specific on resistance. However, high ON current is achieved in Conventional (Conv.) JL DG MOSFET by using high doping concentration at the cost of high OFF current which leads depletion mode operation. Moreover, low doping, narrow channel thickness and high work function gate materials are using to operate Conv. JL DG MOSFET in enhancement mode (Vth > 0Â V for N-JL DG MOSFET, Vth < 0Â V for P-JL DG MOSFET) but ON current is reduced in all above mentioned solutions. To overcome the above mentioned problems, a new architecture is developed called Recessed JL DG MOSFET. In Recessed JL DG MOSFET silicon region is recessed under the gate region and some gate portion is extended towards source and drain region. Recessed JL DG MOSFET shows the same ON current as achieved in Conv. JL DG MOSFET with very low OFF current (leakage current) by considering high doping concentration. Surface potential, electron density, energy band distribution, drain current have been investigated to proof the enhancement mode operation of Recessed JL DG MOSFET. Figure of Merits (FOMs) for RF performance such as Trans-conductance, capacitance and intrinsic power gain (S21), Trans-conductance frequency product (TFP), Gain frequency product (GFP) and Gain trans-conductance frequency product (GTFP) have also investigated of Recessed JL DG MOSFET

Electric current driven formation of micro-and nano-sized beads in thin Cr films

Nano films of chromium with thicknesses from 20 to 200 nm were deposited on silicon substrates and were treated by electric current induced by AFM tip in ambient atmosphere. The melting on the nanoscale, electric current induced migration of the material and chemical reaction of oxidization of chromium were revealed in melting craters around the point of application of the current by optical and electronic scanning microscopy, AFM, and Raman spectroscopy. The flow of the material induced by electric current is accompanied by formation and motion of the matrix of the spherical nanoparticles (beads) in the crater of melt on its periphery. The reaction of chromium oxidation and surface tension of the melted material on the silicon substrate are expected to be responsible for the matrix of nano beads formation under comparatively small currents. Raman spectroscopy confirms that in the vicinity of the periphery of the melted craters around AFM tip application, the beads of oxide phase Cr2O5 are present

Phase inconsistency as a major source of error in NGFS forecast

South Asian monsoon exhibits multiscale spatiotemporal variability. Analyzing the nature and behavior of numerical weather forecast error associated with these space-time heterogeneities will eventually help in improving the models. We investigate the spatiotemporal error characteristics of the National Centre for Medium-Range Weather Forecasting (NCMRWF) Global Forecast System (NGFS) model over South Asian land and ocean separately. Although error grows with lead-time, it saturates within 3�5 days of forecast initiation. The saturated error is only about 15�25 higher than that of day-1, indicating that most of the error accumulates within first 24-h of forecast. Increase in error over oceanic regions is due to an increase in the area with high error at all precipitation ranges with large day-to-day variability. However, over land error growth is primarily confined at locations of high mean precipitation. Decomposition of error arising due to intensity and phase variations reveals that about 90 of it arises from the model�s inability to capture phase of precipitation at various timescales. We show that NGFS cannot capture synoptic scale variations (< 10 day) after day-2. Both the high-frequency (10�20 day) and low-frequency (30�60 day) intraseasonal variations are reasonably predicted up to day-3. At diurnal timescale, NGFS forecasts show a peak in precipitation about 3�6 h prior to that observed, both over land and ocean. Surprisingly, this error does not change with lead-time. Lastly, we show that major error characteristics do not depend on the seasonal mean monsoon rainfall

Quantum channels over graph states using generalized measurement-based quantum computation framework

Measurement-based quantum computation (MBQC) is an alternative way of quantum information processing that describes the unitary evolution of a quantum state using the cluster state and well-defined sequential measurements. We give a closed form expression for the unitary evolution that a state goes through in terms of the network parameters and measurement outcomes on various qubits of the network. We extend the framework of MBQC to describe quantum channels. Using the new framework, we define a valid quantum unital channel between any two nodes of a graph consisting of nodes connected by edges. We describe the channel in terms of the network parameters and initial state. Our generalization consists of modifying the unitary operation, measurement operators, initial arbitrary state of the qubits at all the nodes of the network. We also study the inverse problem of devising an appropriate approximate unitary in the generalized MBQC to create any given quantum channel

Ion pair correlations due to interference between solvent polarizations induced in water

Motions of two distinct ions can get correlated because the polarization induced by the ions can propagate through intervening water and can interfere with each other. This important aspect, which is not included in the continuum model based theories, has not been studied adequately. We calculate the effective force between two oppositely charged and similarly charged ions fixed in water as a function of separation distance R. At short separations, R less than 1.5 nm, the effective force vastly differs from the 1/ϵsR2 dependence advocated by the screened Coulomb's force law (SCFL), where ϵs is the static dielectric constant of the medium. This breakdown of the SCFL is shown to be due to the persistent interference between the polarizations created by the two charges in a manner similar to the vortex-antivortex pair formation in the XY model Hamiltonian. The distance dependence of dielectric constants, ϵs(R), extracted from our simulation exhibits interesting features and can be used in future modeling. In addition, we show that the force-force time autocorrelation between two neighboring ions decays differently at short separation and analyze the friction on the ion pair at different separation distances

Raman Spectroscopy Study of Phonon Liquid Electron Crystal in Copper Deficient Superionic Thermoelectric Cu2- xTe

Superionic Cu2-xTe (CT) is an interesting and emerging p-type thermoelectric (TE) material due to the existence of various polymorphic phases and crystal structures, which undergo several structural phase transitions. On the basis of the stoichiometry of the CT compounds, the structure parameters, the carrier concentration (np), and the thermal conductivity (κ) can be modulated for optimum TE performance. Further, the understanding of the fundamental properties and their impact on TE parameters is not well understood because of their complex structures. We have investigated the vibrational properties of CT compounds such as Cu1.25Te (CT1.25), Cu1.6Te (CT1.6), and Cu2Te (CT2) using temperature dependent Raman studies in the temperature range of 300-773 K. Several structural phases are probed through remarkably distinct spectra for the CT compounds. The temperature transitions are complex such as (i) eutectic melting into CuTe and Te for both CT1.6 (above �593 K) and CT1.25 (above �613 K) and (ii) the structural transition from trigonal to orthorhombic and cubic phase for CT2 (above �553 K), which are strongly manifested in the Raman study. Further, the role of np in the Raman spectra has also been investigated. The intensity of the Raman modes (&gt;100 cm-1) showed strong np dependence due to strong plasmon-phonon coupling. The analysis of full width at half-maximum (fwhm) of Raman peaks and qualitative estimation of phonon lifetime (�i) showed that CT2 has the minimum lattice thermal conductivity

An ultralow power nanosensor array for selective detection of air pollutants

Semiconducting metal oxide gas sensors typically operate at a high temperature and consume hundreds of milliwatts of power. Therefore there is great demand for the development of a low-power gas-sensing technology that can sensitively and selectively detect the gas analytes present in the atmosphere. We report an ultralow-power nanosensor array platform, integrated with an independently controlled nanoheater of size 4 mu m x 100 nm, which consumes similar to 1.8 mW power when operated continuously at 300 degrees C. The heaters exhibit a fast thermal response time of less than 1 mu s, and can be utilized to operate in duty cycle mode, leading to power saving. The active area of the nanosensor is 1 mu m x 200 nm, defined by sensing electrodes with a nanogap of similar to 200nm, leading to small form factor. As a proof of concept, each of the sensing elements in the array is functionalized with different sensing materials to demonstrate a low-power, sensitive and selective multiplexed gas-sensing technology for the simultaneous detection of CO (similar to 93.2% for 3 ppm at 300 degrees C), CO2 (similar to 76.3% for 1000 ppm at 265 degrees C), NO2 (similar to 2301% for 3 ppm at 150 degrees C) and SO2 (similar to 94% for 3 ppm at 265 degrees C). The technology described here uses scalable crossbar architecture for sensor elements, thus enabling the integration of additional sensing materials and making it customizable for specific applications

The digital twin of discrete dynamic systems: Initial approaches and future challenges

This paper employs a discrete damped dynamic system to investigate the emerging concept of a digital twin. Dynamic systems are well understood across engineering and science domains, and represent a familiar and convenient platform for exploring the various aspects of a digital twin design. The aim is to create a framework accessible to engineering sciences related to the aerospace, electrical, mechanical and computational area. The virtual model of the physical system is expressed as a differential equation in two-time scales, with the concept of a slow time being used to separate the evolution of the system properties from the instantaneous time. Cases involving stiffness variation and mass variation are considered, individually and together. It is assumed that the damped natural frequency and the time response are measured through sensors placed on the physical system. Issues of errors and reduced sampling rate in sensor measurements on the digital twin are investigated. The digital twin is expressed as an analytical solution through closed-form expressions and the effect of sensor errors is brought out through the simulations. Several key concepts introduced in this paper are summarized and ideas for urgent future research needs are proposed. The current work breaks free from the qualitative description of digital twins pervading the literature and can be used as benchmark solutions to validate digital twin of experimental dynamic systems and their implementation using sensors, the internet of things and deployment on the cloud computing systems

Advances in liposomal drug delivery to cancer: An overview

Liposomes are biodegradable and biocompatible lipid bilayer vesicles which are widely exploited as preferred carriers for smart delivery of both hydrophobic as well as hydrophilic bioactives. Structural fabrication of liposomes for ligand anchoring, long-circulation and stimuli-responsiveness are advancing features to meet the needs of clinical and industrial demands. Recent studies report newer developments in multipronged liposomes for synchronized theranostic manifestations in cancer treatment. This review gives an insight to advances in ligand targeted liposomes (like folate, mannose, transferrin, hyaluronic acid, antibody, aptamer, and peptide, etc.), stimuli-triggered liposomes (stimuli such as pH, temperature, and hypoxia, etc.) and liposomes mediated autophagy modulation, and theranostic liposomes for the diagnosis and treatment of cancer. It also includes patents, clinical studies and marketed liposomal products. This assemblage of advances would be of great interest to budding scientists and pharmaceutical companies engaged in the development of liposomes