Nikos Konofaos

Aristotle University of Thessaloniki | AUTH · School of Informatics

This paper introduces a mixed-logic design method for line decoders, combining transmission gate logic, pass transistor dual-value logic and static CMOS. Two novel topologies are presented for the 2-4 decoder: a 14-transistor topology aiming on minimizing transistor count and power dissipation and a 15-transistor topology aiming on high power-delay...

Compressors are the fundamental components in the partial product reduction stage of CMOS multipliers. This letter presents a new design for the CMOS 5-2 compressor with 58 transistors, which is the lowest reported device count for such a circuit. Simulation results show that the proposed 5-2 compressor has significantly improved power-delay perfor...

In this paper, we introduce the Multiple-Output Monotonic CMOS (M2CMOS) logic style, which is applied on the design of a high-performance and energy-efficient 64-bit incrementer/decrementer circuit. M2CMOS is proposed as an enhancement to standard monotonic-static logic and a viable alternative to domino logic for high-performance applications. A s...

Quantum pattern recognition techniques have recently raised attention as potential candidates in analyzing vast amount of data. The necessity to obtain faster ways to process data is imperative where data generation is rapid. The ever-growing size of sequence databases caused by the development of high throughput sequencing is unprecedented. Curren...

We propose an architecture based on Quantum Cellular Automata which allows the use of only one type of quantum gate per computational step, using nearest neighbor interactions. The model is built in partial steps, each one of them analyzed using nearest neighbor interactions, starting with single-qubit operations and continuing with two-qubit ones....

In this paper, we introduce a novel coding scheme, which allows single quantum systems to encode multi-qubit registers. This allows for more efficient use of resources and the economy in designing quantum systems. The scheme is based on the notion of encoding logical quantum states using the charge degree of freedom of the discrete energy spectrum...

Optically controlled self-assembled quantum dots have received substantial attention in the quantum computing area, as techniques for initializing, manipulating, and reading out single spin qubits have been demonstrated in essence. The electron-spin coherence and hole-spin coherence are limited due to noisy quantum effects, and there is a significa...

A novel SRAM architecture that simultaneously accesses multiple and non‐overlapped memory subregions, located even inside the same memory page, is presented in this work. This new memory architecture is called multi‐field SRAM, and the multiple selection of its subregions—referred to as the memory fields—is succeeded using special designed intra‐en...

Multilayer structures consisting of TiNx-SiO2-Si layers operating as MOS devices were constructed and tested for their electrical properties. RBS measurements were performed for the characterization of the structure of the devices. The results show a correlation between the structure found by RBS and the electrical performance of the devices.

Multi layer structures consisting of TiN — SiO2 — Si layers operating as MOS devices were constructed and tested for their electrical properties. RBS and resonance reaction analysis were performed for the characterisation of the structure of the devices. The results show a correlation between the structure found by RBS and the electrical performanc...

A dot matrix approach for sequence alignment is combined with a known quantum multi-pattern recognition method in order to improve the problem of sequence alignment. This dot matrix technique allows the application of some quantum computing principles on the pattern recognition problems like those used in the Grover's algorithm. When the recognized...

Memory devices having the structure of n-Si(1 0 0)/SiO2/metal nanocrystals (NCs)/Y2O3/Au were fabricated and their structural and electrical characteristics have been studied extensively. Gold nanoparticles were formed via laser annealing (LA) of a thin Au layer. The aim was to investigate the use of laser annealing as an effective method to produc...

The quantum noise encumbrance caused by quantum error-correcting protocols is studied via numerical treatments. Noise evolution implies that the noise magnitude order may change dynamically during quantum computations. The rate of noise level deterioration is a function of the computer’s architecture and physical implementation. Various stabilizer...

In this paper a VHDL implementation of the Hummingbird lightweight cryptographic algorithm is presented, with the initialization, encryption and decryption processes analyzed and simulated. All these processes include stream cipher and block cipher encryption or decryption techniques, such as transposition with linear transform and substitution wit...

Typical memory addressing, where a row of cells that forms the memory word, is addressed every time the memory is accessed, has the disadvantage of decreased addressing flexibility, originating from the strict addressing method and leading to addressing limitations. In this work we present and implement the crossbar addressing scheme, where the mem...

A high-performance and energy-efficient 256-bit CMOS priority encoder is presented and realized on transistor level using 32 nm predictive technology. The new circuit is designed with a full custom approach and incorporates 2 novel logic styles: the Multiple-Output Monotonic CMOS (M2CMOS) and the Dynamic Inversion technique (DI). The achieved perfo...

An ultra-low-power, 55-transistor 8-bit priority encoder is proposed, based on a modified n-type dynamic scheme using feedback from higher- to lower-priority outputs. A comparative study, including other designs from literature, is performed on transistor level at 32 and 45 nm predictive technology. The simulation results showed that, compared to t...

In this work, a novel architecture that simultaneously accesses multiple and non-overlapped sub-regions of a static random access memory, is presented. The selection of the multi memory fields is succeeded via intra-encoders, placed one for every memory field. The addressing of the memory is done using a modified approach of the crossbar addressing...

Proper use and evaluation of the pulse oximeter readings in everyday clinical practice are related to patient safety and quality of provided patient healthcare. Purpose of this study was the evaluation of Greek registered nurses’ knowledge in pulse oximetry before and after an educational intervention implemented in a 2-h educational intervention (...

International literature reveals the deficit of nurses’ knowledge on the defibrillator and the need to implement continuing education training courses relative to clinical issues. The purpose of this study was the evaluation of Greek registered nurses’ knowledge on the safe use of the defibrillator before and after a 2-h workshop. Anonymous self-ad...

Memory devices having the structure of n-Si(100) / SiO2 / metal nanoparticles (NCs) / Y2O3 were fabricated and their structural and electrical characteristics have been studied extensively. The aim was to investigate the potential use of laser annealing as an effective method to produce effective memory devices of that kind.

We propose an architecture based on Quantum cellular Automata which allows the use of only one type of quantum gates per computational step in order to perform nearest neighbor interactions. The model is built in partial steps, each one of them analyzed using nearest neighbor interactions, starting with single qubit operations and continuing with t...

A comparative study of various 6T SRAM cell layouts is presented at 32 nm, including four symmetric topologies. The comparison comprises two conventional cells, a thin cell, which is the current industry standard, and a recently proposed ultrathin cell. The evaluation is based on area efficiency, power dissipation and read/write delay, all of which...

An electronic design and evaluation tool for quantum circuit design is presented. It allows easy implementation of quantum algorithms based on the circuit model of quantum computation. The layout of an ideal circuit network can be designed in the logical layer and then automatically get converted into an encoded form closer to the physical layer. T...

The performance of priority encoder circuits is usually limited by the delay associated with the propagation of the priority token, however, proper design in the architectural level can reduce the delay stages to the order of O(log n). Furthermore, power dissipation and area pose an increasingly important concern in modern circuit design, thus the...

A comparative study of various 6T SRAM cell layouts is presented at 32 nm, including four symmetric topologies. The comparison comprises two conventional cells, a thin cell, which is the current industry standard, and a recently proposed ultrathin cell. The evaluation is based on area efficiency, power dissipation and read/write delay, all of which...

Recent advances in CMOS technology involve materials progress, new device structures as well as new design techniques in nanoscale circuits. The 32 nm design rules using classical CMOS devices and various materials for metal interconnects, allow the design of basic circuits with low power consumption, low delay times and low transistor numbers. In...

Six layout variations of the 6T SRAM cell are examined and compared. The comparison includes four conventional cells, plus the thin cell commonly used in industry and a recently proposed ultra-thin cell. The layouts of the cells are presented and corresponding memory arrays are implemented at 65, 45 and 32 nm using 3-metal CMOS n-well process. The...

A comparative study of various 6T SRAM cell layouts is presented at 32 nm, including four symmetric topologies. The comparison comprises two conventional cells, a thin cell which is the current industry standard and a recently proposed ultra-thin cell. The evaluation is based on area efficiency, power dissipation and read/write delay, all of which...

In this letter, the finite difference time-domain (FDTD) method and the ray-tracing (RT) technique are systematically revisited and compared as potential tools that can reliably characterize new protocols for emerging nanonetwork applications. To this aim, a set of efficient simulation schemes for the precise prediction of the reception quality in...

During the past decade, organic photovoltaics (OPVs) have attracted great attention because of their light weight and potential low cost thanks to low-temperature printing techniques on flexible substrates. In spite of their high power conversion efficiency, the traditional bulk-heterojunction (BHJ) architecture has limitations in terms of device s...

Substoichiometric tungsten oxide nanostructured films were synthesized by a hot-wire deposition technique in hydrogen-rich environment and characterized for their structural and electrical properties. A semiconducting behaviour was identified, allowing n-type conductivity even at room temperature which is an important result since it is well known...

We report on the dielectric degradation of Rare-Earth Oxides (REOs), when used as interfacial buffer layers together with HfO2 high-k films (REOs/HfO2) on high mobility Ge substrates. Metal-Oxide-Semiconductor (MOS) devices with these stacks,show dissimilar charge trapping phenomena under varying levels of Constant- Voltage-Stress (CVS) conditions,...

Here we report on the improved performance of hybrid polymer light emitting diodes (HyPLEDs) upon inserting an ultra thin layer of partially reduced tungsten oxide (WO(2.5)) or molybdenum oxide (MoO(2.7)), deposited (by heating a W or Mo filament while hydrogen was flowing through the chamber) at the polymer/Al cathode interface. Improved current d...

With the advent of nanotechnology the synthesis of nanostructured materials and their useful applications have become increasingly prominent. Nanostructuring can enhance the performance of functional materials and provides them with unique properties. Exceptional qualities of nanostructured materials compared to the bulk include: (i) increased surf...

Gate stacks (rare-earth oxides, REOs-HfO2) grown on Germanium substrates using REOs (e.g. CeO2, Dy2O3, La2O3) as an interfacial buffer layer which are also friendly with Ge, demonstrating better passivation and electrical properties [1]. However, it is imperative to study a number of reliability concerns such as, accumulation of charge at the inter...

Tungsten oxide (WO(3)) films with thicknesses ranging from 30 to 100 nm were grown by Hot Filament Vapor Deposition (HFVD). Films were studied by X-Ray Photoemission Spectroscopy (XPS) and were found to be stoichiometric. The surface morphology of the films was characterized by Atomic Force Microscopy (AFM). Samples had a granular form with grains...

We report a significant improvement in the performance of single layer polymer light-emitting diodes (PLEDs), based on the green emitting copolymer poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(1,4-benzo-{2, 1',3}-thiadiazole)], upon inserting a very thin layer of partially reduced molybdenum oxide (MoOx, where x=2.7) at the polymer/Al cathode interface...

p>We report a significant improvement in the performance of single layer polymer light-emitting diodes (PLEDs), based on the green emitting copolymer poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(1,4-benzo-{2, 1′,3}-thiadiazole)] , upon inserting a very thin layer of partially reduced molybdenum oxide (MoO_x, where x=2.7) at the polymer/Al cat...

We report the use of nanostructured metal oxides as cathode interfacial layers for improved performance hybrid polymer electronic devices such as light-emitting diodes (PLEDs) and solar cells. In particular, we employ a stoichiometric (WO3) and a partially reduced tungsten metal oxide (WOx) (x<3), both deposited as very thin layers between an alumi...

Undoped high quality (0 0 2) zinc oxide thin films were grown on (1 0 0) silicon substrates by pulsed laser deposition (PLD). The films were developed at low growth temperatures between 200 and 300 °C, and a range of oxygen pressures from 8.5 × 10−5 to 2.6 × 10−4 Torr. X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and room temper...

We report the use of nanostructured metal oxides as cathode interfacial layers for improved performance hybrid polymer electronic devices such as light-emitting diodes (PLEDs) and solar cells. In particular, we employ a stoichiometric (WO3) and a partially reduced tungsten metal oxide (WOx) (x<3), both deposited as very thin layers between an alumi...

The design and simulation of a single-electron 4-1 complementary multiplexer is being presented using two Monte Carlo based tools. Both the behavior and the stability of the circuit were verified while its free energy and its speed were also examined and analyzed. The results confirmed that the circuit behaved as a complementary multiplexer. Moreov...

The design and simulation of a single-electron OR/NOR gate is being presented using a Monte Carlo based tool. Both the OR/NOR behavior and the stability were verified while the free energy behavior of the circuit was also examined. The results confirmed that the circuit behaved as an OR/NOR gate, depicting improved characteristics than previously p...

In this paper a technique for a quantum computer architecture is demonstrated using the discrete energy levels of an impurity doped semiconductor to represent the quantum computational basis. External signals are used to perform quantum logical gates and recombination mechanisms are suitably modelled in order to demonstrate quantum information proc...

A novel approach toward the indoor position localization of a mobile target is presented in this paper. It is based on the reception quality of infrared patterns that are sent by a small number of transmitters that are placed around the covered area. A pair of transmitters can cover an area of 15 m² that can be further -extended if more...

In this paper the design and simulation of a single-electron 2-4 decoder based on NAND gates is presented. The simulation was made using a Monte-Carlo based tool. The results confirmed that the circuit was behaving as a 2-4 decoder. The stability plot and the free energy history diagrams offer detailed analysis of the circuit. The results were comp...

A model of quantum information processing is proposed for applications in health-care and assistive environments. It uses implanted nano-chips which could incorporate quantum computing technology and make use of the advantages of high computing and large memory capacity of a quantum system to the data storage procedure of a medical sensor. Quantum...

In this paper, we present a single-electron 2-4 decoder built using single-electron devices. The circuit is designed using a proper tool based on a Monte Carlo technique. First a single-electron AND gate is studied and then the 2-D decoder circuit is designed and studied. The results proved that the circuit was a 2-4 decoder, while the behaviour of...

The aim of our work is to demonstrate a way of combining two different methods of achieving Quantum Computation: a) Kane's semiconductor based quantum computer and b) Quantum Cellular Automata (QCA). In our work, we demonstrate the physics, we propose the model and the circuit and we estimate the error in computation. The amount of error due to dec...

In this paper we present NAND gates designed using single electron logic. First the single-electron NAND behaviour is studied and then the energy performance of the circuit is examined. The whole design and simulation is made using a Monte-Carlo based tool. The results proved that the circuits were behaving as NAND gates, while the free energy stud...

Up to date, MOSFETs have been made through well established techniques that use SiO2 as the gate dielectric and the related design issues are well established. The need to scale down device dimensions allowed researchers to seek for alternative materials, in order to replace SiO2 as the gate dielectric. The implementation of such MOS devices in mem...

In this paper we present a way to locate the position of a moving target on a grid plane of about 15 square meters with an estimation error of less than half of the grid node distance. The estimation method is based on the success rate that the infrared patterns transmitted from two constant positions is received by the moving target. Several aspec...

A novel method for the indoor localisation of a target was presented in this chapter. This method is based on measuring the number of the digital infrared patterns received by the target in a specific time interval (success rate). At least two transmitting devices are placed around the covered area that exceeds 15m2, while a pair of infrared receiv...

The testing and evaluation of a low cost system capable of estimating the position of a moving target within an extendible indoor area with low error is presented. Based on a recently developed system architecture, which makes use of a noise-sensitive indoor localization system made up of ir sensors, the position estimation error is based on compar...

Germanium technology aiming at the fabrication of functional devices strongly depends on the electrical behaviour of both the oxide bulk and the oxide/Ge interface. Field effect transistors underperform and express non ideal characteristics due to high values of interface defects in conjunction with bulk states. In this paper, we show that rare ear...

The location of a moving person or vehicle in a virtual reality environment is a critical issue. A wireless infrared sensor network capable of estimating the position of a target on a plane and its orientation is presented in this paper. This is actually an extension of the position estimation system that was presented in [1-2] where the target was...

The design, installation and operation of an Automatic Weather Station (AWS) are described and analysed in the present paper. This station of high endurance is easy to be installed and capable for long-time operation without significant problems. The metadata of the station which are the characteristics of the instruments, electronic logic control...

The dynamics of a single qubit, encoded in the charge states of a singly ionized phosphorus atom embedded in silicon bulk material are studied. For the simulation of the system a suitably modified version of the MATLAB package SCHRODINGER was used. Preliminary results were in agreement with previously published work regarding single qubit rotations...

The architecture of an indoor target localization system employing a small number of infrared-emitting diodes and sensors is presented in this paper. The properties of infrared light and magnetic fields have already been exploited for position localization in distances of several centimeters. Ultrasonic waves and laser light can be used for longer...

The location of the position of a moving target on a grid plane is studied in this paper. The estimation method is based on encountering the number of infrared patterns that arrive to the target as expected, unexpected or out of order. Since the position of the target is not determined by an analog signal intensity, no high precision sensors and me...

In this study, we designed and simulated MOS devices having alternative gate dielectrics and examined their electrical behaviour as well as their effectiveness on the performance of a DRAM cell containing them. The devices under test had gate dielectrics of SrTiO₃, (Ba_1-xSr_x)TiO₃, TiO₂, Ta<sub>...

In this paper we present a system that is capable of estimating the position of a moving target on a grid plane covered by a pair of infrared transmitters. The area of this plane can be up to 15m2, further expandable if multiple transmitters are used. The position estimation method is based on comparing the number of infrared patterns received to t...

A new architecture for the practical implementation of a quantum computer is presented in this paper. The architecture makes use of the recombination statistics that govern semiconductor devices and I particular quantum phenomena occurring inside the forbidden gap of a semiconductor filled with a controlled amount of impurities. The occupation of a...

Highly uniform BaTiO3 (BTO) films with thickness well below 100 nm were deposited on p-Si by spin coating using a modified polymeric precursor method. The polymeric precursor gel was redissolved into glacial acetic acid to improve the wetting property of the spinning solution to the Si substrates (2.5-in. diameter). The morphology, composition, thi...

The design of an embedded DRAM based on MOSFETs with alternative gate dielectrics is presented and analysed. Design and evaluation of NMOS devices with high-k dielectric gate insulators and DRAM circuits took place. Reliability parameters of the NMOS devices constructed with (Ba,Sr)TiO3 gate dielectrics were examined. A 90 nm technology model and t...

Design and construction of new sub-micron MOSFETs with alternative gate dielectrics has emerged as a new technology for use in high-performance logic or low power memory circuits. The modelling of the new devices needs to take into account the effects that the new dielectrics have on the MOS device performance. In this paper, we examine such effect...

In this paper a quantum computer based on the recombination processes happening in semiconductor devices is presented. A ``data element'' and a ``computational element'' are derived based on Schokley-Read-Hall statistics and they can later be used in order to manifest a simple and known quantum algorithm. Such a paradigm is shown by the application...