Electrical Engineering

Elektrik Mühendisliğinin Sosyal Hayatın Gelişimi Üzerine Etkileri

by mehmet cem ates

Mühendislik bilimsel ve teknik bilgileri problemleri çözmek ve insan ihtiyaçlarını karşılamak için kullanma sanatıdır. İnsanoğlu tarihin ilk devirlerinden beri mühendisliğin temel olgularını kullanmış, son elli yıldan beridir de mühendisliği uzmanlaşma alanına oturtmuştur. Bu uzmanlaşmayla birlikte mühendisliğin hayatımız üzerine olan etkileri daha net biçimde ortaya çıkmış, mühendislik ve gelişim kavramları birlikte anılmaya başlanmıştır. Şüphesiz ki hayatımızda bir dönüm noktası olan elektrik ve bu elektriği var eden ve sistemleştiren elektrik mühendisliği, insan yaşamını teknik açıdan olduğu kadar sosyal yönden de gelişmesine en çok katkıda bulunan mühendislik dallarından biridir.   

Extinction of ferromagnetism in highly ordered pyrolytic graphite by annealing

by Sefaattin Tongay

We report that the ferromagnetism of highly ordered pyrolytic graphite (HOPG) samples as measured by hysteretic... more We report that the ferromagnetism of highly ordered pyrolytic graphite (HOPG) samples as measured by hysteretic magnetization loops can be diminished and eventually extinguished with sufficiently long high vacuum anneals at temperatures on the order of 2300 °C. Concomitant with the extinction of ferromagnetism, we observe an anneal-induced increase in grain size (accompanied by possible edge reconstruction) confirmed by X-ray diffraction measurements and improved transport properties, including lower in-plane and out-of-plane resistivity, higher electron and hole mobility and improved charge compensation. The implied reduction of defects and vacancies by annealing suggests that the ferromagnetism of pristine HOPG is correlated with localized states located at zigzag edges, vacancies and related defects.

Wind-influence modeling for outdoor thermographic surveys

by Guilherme Bastos

Thermosense XXXII, 2010

An alternative model to determine the wind influence from themographic inspections is addressed in this paper. A wind... more An alternative model to determine the wind influence from themographic inspections is addressed in this paper. A wind velocity dependent temperature reduction factor is developed and applied in order to estimate the target temperature in the absence of wind. The model makes use of only two unknown coefficients, which are identified for each case. Tests were conducted in laboratory using an aclimatiezed chamber developed to simulate actual conditions, as well in the field. The results of application were also compared to those obtained from other researchers, showing very good agreement.

Extracting Load Current Influence From Infrared Thermal Inspections

by Guilherme Bastos

Published on IEEE Transactions on Power Delivery, 2011, pp. 501-506.

This paper presents some difficulties encountered when evaluating information obtained from infrared thermal... more This paper presents some difficulties encountered when evaluating information obtained from infrared thermal inspections conducted in uncovered power substations. Technical, physical, and environmental factors are the main influences that have been identified. Based on field data and laboratory tests, mathematical models were derived to understand the load current variation influence on the thermal behavior of electrical components, which are suitable either to extract its influence or forecast the system behavior under specified conditions of interest.

Development of an acclimatiezed chamber for IR based diagnostic research

by Guilherme Bastos

Draft only. Published in Proc. of 10th Quantitative Infrared Termography - QIRT 2010.

Electromagnetic tracker measurement error simulation and tool design

by Gregory Fischer

Two Welsh Wizards: The roles of William Preece and David Hughes in electrical engineering in the nineteenth-century

by Elizabeth Bruton

Presented before a joint meeting of the Institution of Engineering & Technology (IET) and Swansea Amateur Radio Society (SARS) at the University of Swansea, Wales on 19 January 2012.

In this lecture, I will give a brief overview of the lives and work of two incredibly talented and hard-working... more In this lecture, I will give a brief overview of the lives and work of two incredibly talented and hard-working electrical engineers, William Preece and David Hughes, both Welshmen.  Despite careers in electrical engineering stretching from the mid-nineteenth century to the end of the century neither would receive the recognition they deserved and would make lasting contributions to the field of electrical engineering, both in terms of developments and also more broadly in their shaping and promotion of the field itself.  It is not surprising that with such a strong degree of similarity that there were many aspects of electrical engineering where their interests and expertise overlapped and converged.  Both men, in their own way, would make dramatic contributions to the field of telephony and the two would have legitimate claims to being early pioneers in the field of wireless telegraphy.  But their interests would best converge with their involvement with the Institution of Electrical Engineers and its committee on electrical standardisation in the 1880s and 1890s.  In the first section of this lecture, I will introduce Preece, Hughes, and the Institution of Electrical Engineers.  At the core of this lecture, lies an analysis and exploration of the work of Hughes and Preece through their involvement in the Institution of Electrical Engineers' committee on electrical standardisation.  I will round off with the contributions of these two “Welsh Wizards” to the field of telecommunications before offering some concluding remarks.

Méthodes d’estimation récursive pour la prévision de la consommation d’électricité: La prévision de courbes de charge par estimation fonctionnelle non paramétrique

by Arijit Das

Ce rapport correspond au Lot 3 du contrat entre EDF et l’INRIA Bordeaux Sud- Ouest sur la prédiction de la... more Ce rapport correspond au Lot 3 du contrat entre EDF et l’INRIA Bordeaux Sud- Ouest sur la prédiction de la consommation individuelle d’électricité. Il est axé sur la prédiction de courbes de charge individuelles à horizon journalier, sur un jeu de données fourni par EDF R&D. Nous nous sommes focalisés sur les clients EDF associés à un jeu de données complet, c’est- à-dire sans "zéros" ni "valeurs manquantes". Le jeu de données représentatif est celui utilisé dans le Lot 2, constitué de 16 clients. Nous étudions ici les méthodes d’estimation fonctionnelle non paramétriques. Le rapport débute par une présentation générale et théorique des estimateurs de fonction de régression. On s’intéresse principalement aux estimateurs à noyau de Nadaraya- Watson, de Nadaraya-Watson récursif et de Révész récursif. La loi forte des grands nombres ainsi que la normalité asymptotique pour ces trois estimateurs sont présentées, ce qui constitue le socle théorique du Lot 3. Ces estimateurs sont ensuite testés sur un jeu de données simulées à l’aide de 8 noyaux différents, pour valider nos méthodes et constater certains résultats issus de la théorie. Les modèles à mettre en place sont par la suite recherchés par une analyse du jeu de données du Lot 2, considéré comme représentatif de l’échantillon global. Les méthodes sont alors lancées en parallèle sur l’ensemble du jeu de données du Lot 3, constitué de plus de 1500 courbes. Pour cela, la configuration optimale pour chaque estimateur est évaluée sur un sous-ensemble, validée sur un autre sous-ensemble avant d’être appliquée à l’intégralité des courbes classifiées. Une approche par ondelettes approfondit enfin l’étude, dans laquelle nous mesurons la ressemblance entre blocs à partir de noyaux sur les coefficients de leur décomposition en ondelettes.

LEDs Brancos Sem Fio

by Jessica Meyer

In Wireless Brasil < http://www.wirelessbrasil.org >

This paper describes the new tecnology of White-LED, that is sitll not well known to the general public. At first, the... more This paper describes the new tecnology of White-LED, that is sitll not well known to the general public. At first, the concept of wireless network and optic wireless will be shown. Then, how this new tecnology works, as well as its pros and contras. At last, its importance and future expectations will be presented.

Dyadic Interaction Assistant For Tracking Head Gestures and Facial Expressions (ISEF Version)

by Varun Ramesh

Co-authored with Shantanu Bala, Supervised by Sreekar Krishna and Dr. Panchanathan at the Cognitive Center for Ubiquitous Computing.

When humans interact with each other, they utilize multiple different channels of communication, including verbal... more When humans interact with each other, they utilize multiple different channels of communication, including verbal communication, facial expressions, and gestures. Approximately 46% of the information delivered in interpersonal communication is solely visual, leaving people with visual impairments at a great disadvantage in social environments, often leading to isolation. The goal of this project is to create a novel assistive device - the Social Interaction Assistant - that can provide people with visual impairments the ability to access visual social cues such as the emotions of the people they are conversing with. The Social Interaction Assistant automatically recognizes different facial indicators of a person’s emotional state and conveys such information discretely and accurately in real-time using haptic (vibration) feedback. The Social Interaction Assistant consists of a camera paired with face detection technology to automatically pan and tilt to track faces and keep them within its field of vision. The video stream from the camera is analyzed in real-time to detect features of the faces such as the curvature of the eyebrows and mouth, in order to determine the emotional state of a subjects face. For this project, a haptic glove was created from scratch (dubbed the VibroGlove). A microcontroller allows the software to vibrate the glove in various patterns corresponding to different visual cues. The device accurately detects and tracks faces with close to 95% accuracy under certain lighting, and can accurately detect various facial features such as the state of the eyebrows and mouth. The software runs at approximately 10 frames per second - enough for what is required for a conversation.

Electric and Magnetic Fields of Compact Transmission Lines

by Miguel Melo

Experimental and theoretical studies of the electric and magnetic fields produced by compact transmission lines are... more Experimental and theoretical studies of the electric and magnetic fields produced by compact transmission lines are described. The lateral and longitudinal field profiles at ground level within a right of way have been analyzed. The studies include measurements of the profiles of field strength of compact transmission lines as well as an analysis relative to the type of tower, size and type of conductor, and voltage level. Finally a comparison between measured and calculated values are presented

A Theory of Media as a History of Electricity How McLuhans thoughts about mediation are thwarted by their negation

by Florian Sprenger

By describing electricity as instantaneous, McLuhan imported a notion of immediacy into his work that contradicts his concept of the medium as the message. These aporias influence all of his central concepts.

RBS STUDY OF THE EFFECT OF ARSENIC AND PHOSPHORUS INTERFACIAL SEGREGATION UPON THE SINTERING OF CONTACTS BETWEEN IMPLANTED POLYCRYSTALLINE SILICON AND ALUMINUM -SILICON(1%)

by Nicole Herbots

Nicole HERBOTS *, Maurice LOBET and Femand Van de WIELE
Microekxtronics Lab, Uniwrsite Catholique de Lmamin, 3, place du Levant. B - 1348 Louvain -la - Neuve, Belgium
Nuclear Instruments and Methods in Physics Research B7/8 (1985) 278-286 North-Holland, Amsterdam

The sintering behavior of the interface between Al :Si(l%) alloy and polycrystalline Si (poly-Si) was studied as a... more The sintering behavior of the interface between Al :Si(l%) alloy and polycrystalline Si (poly-Si) was studied as a function of the poly-Si implantation dose by combining RBS, SEM, TEM and X-ray microanalysis. Two different N-dopants were used: arsenic and phosphorus. The dopants were implanted in the poly-Si layer and thermal annealing was used to obtain dopant segregation towards the poly-Si interfacea.
After sir&ring, two main effects were detected: (1) Al-Si eutectic phase precipitates and Si crystallites are formed at the interface. (2) The density of precipitates is a function of the implantation dose. For doses above 1 x lOI5 at./cm2. segregated arsenic and phosphorus are found to completely inhibit this precipitation process, provided that the segregation peak of the dopant profile is preserved before metallization.
Several conclusions can be drawn: for surface concentrations higher than 8~10’~ at./cm3, arsenic and phosphorus inhibit the precipitation of the Al-Si eutectic phase, and thus inhibit interactions between the films at the interface. Moreover, argon gas, usedfor sputtering deposition of aluminum, segregated at the poly-Si/Al: Si(l%) interface and may also inhibit the metal-semiconductor interdiffusion.

Thin film formation from low energy ions: new kinetic paths, new properties, new phases

by Nicole Herbots

N Herbots (Massachusetts Institute of Technology, USA)

MATERIALS & DESIGN Vol. 13 No. 2 APRIL 1992

MRS fall meeting: A selective review

Advances in the science and technology of communication and computing devices (electronics and optoelectronics... more Advances in the science and technology of communication and computing devices (electronics and optoelectronics devices) have relied heavily during the second half of the 20th century upon the scaling down of device dimensions. These dimensions are now close to the average distance between atoms in solid matter. More specifically, the very operation of new devices depends critically on the arrangement of atoms at interfaces, ie the junction of two different materials, as shown in Fig. 3. Interfaces are now often confined within one single atomic plane. In addition to the decrease in spatial dimen- sions, the complexity of the material structure has increased significantly as well. For instance, the number of interfaces found in a device has multiplied. This has led to the name of 'artificially structured materials', to emphasize the remoteness of atomic arrangement found in such structures with respect to those found as 'naturally occurring in nature'.
These structures can be described as a succession of ultra- thin solid films. These films are often epitaxial - from the Greek epi-, skin or surface, and -taxos, order - which means that each atomic layer is organized as in a periodic crystal, even at heterointerfaces where different materials join,

A quantitative model of point defect diffusivity and recombination in ion beam deposition and combined ion and molecular deposition

by Nicole Herbots

O. Vancauwenberghe, N. Herbots, and O. C. Hellman MassachusettsInstituteo/Technology, 77MassachusettsAvenue. Cambridge. jWassachusetts02139
(Received 18 October 1990; accepted 12 February 1991)
J. Vac. Sci. Techno!. B 9 (4), JullAug 1991, p.2027-2033 0134-211X/911042027-07$01.00 @ 1991 American Vacuum Society 2027

We are investigating the use of low energy ions (< 1 keV) in low temperature thin film growth techniques, ion beam... more We are investigating the use of low energy ions (< 1 keV) in low temperature thin film growth techniques, ion beam deposition (IBD) and combined ion and molecular deposition (CIMD). In IBD, a thin film is directly grown from a low energy ion beam as the only source of material, while in CIMD, low temperature growth of thin films is achieved by depositing materials simultaneously from a low energy ion beam and one or several molecular beams. A simple model of the IBD process has been developed and accounts for atomic collisions and thermal diffusion during thin film growth. Computer simulation of IBD of Si on Si have been conducted as a function of ion energy to support more quantitatively this physical description of IBD. The results show that the IBD growth mechanism is mediated by the fast diffusing interstitials and establish a low energy limit to achieve epitaxial growth by IBD that depends on the point defect diffusivities. The defect generation has to be confined in the subsurface region in order to favor interstitial recombination with the surface, leading to net thin film growth, and vacancy annihilation to prevent amorphization. The effect of point defect diffusivities on the IBD growth process is also investigated. It is found that a model including fast moving interstitials can account for various experimental observations specific to IBD.

Ion-solid interactions during ion beam deposition of 74Ge and 30Si on Si at very low ion energies (0-200 eV range)

by Nicole Herbots

ION-SOLID INTERACTIONS DURING ION BEAM DEPOSITION OF 74Ge AND 30Si ON Si AT VERY LOW ION ENERGIES (O-2OO eV RANGE)*
N. HERBOTS, B.R. APPLETON, T.S. NOGGLE, R.A. ZUHR and S.J. PENNYCOOK
Solid State Division, Oak Ridge National Laboratory, PO Box X, Oak Ridge, TN 37831, USA
Nuclear Instruments and Methods in Physics Research B13 (1986) 250-258 North-Holland, Amsterdam

Atomic collisions in solids in the 40-200 eV energy range have been studied both theoreticalIy and experimentaIiy to... more Atomic collisions in solids in the 40-200 eV energy range have been studied both theoreticalIy and experimentaIiy to determine the feasibility of the ion beam deposition (IBD) of amorphous and/or epitaxial layers. IBD was first modeled by a rate equation including the target sputtering yield and the ion self-sputtering, range and range straggling. To obtain preliminary values of those parameters, Monte Carlo simulations with TRIMSPUT were used. The surface binding energy (SBE) appeared to be an important parameter of the simulation for sputtering yields under 200 eV. By fitting the SBE with available sputtering data for Ar on Si below 1 keV, a very good agreement waso obtained between simulations and sputtering data of other ion-target combinations. Experimentally, 30Si and 74Ge ions were deposited on Si( 100) at 300 K and 700 K. Cross-section TEM combined with ion scattering and ion channeling showed that IBD can provide very thin (3 nm) though perfectly continuous films with sharp interfaces (<l nm). IBD damage to the substrate saturates as a function of dose, is negligible below 4OeV, and presents an interesting annihilation/long range diffusion behavior as a
function of the temperature during irradiation.

Long range ordered semiconductor interface phase and oxides

by Nicole Herbots

Herbots; Nicole (Tempe, AZ), Atluri; Vasudeva P. (Scottsdale, AZ), Bradley; James D. (Gilbert, AZ), Swati; Banerjee (Chandler, AZ), Hurst; Quinton B. (Tempe, AZ), Xiang; Jiong (Tempe, AZ)

A semiconductor processing method capable of producing highly ordered, ultra thin dielectrics, including gate oxide... more A semiconductor processing method capable of producing highly ordered, ultra thin dielectrics, including gate oxide and other semiconductor dielectrics, and interphase phases with low defect density. The process includes a degrease step, an etch, primary oxidation and then a passivation step which utilizes hydrofluoric acid to passivate the cleaned silicon surface with hydrogen. Dielectric layers may then be formed with low interface defect density, low flat band voltages and low fixed charge on semiconductor substrates.

Arsenic Dopant Influence upon the Sintering Behavior of the Aluminum‐Polysilicon Interface

by Nicole Herbots

REF: J. Electrochem. Soc., Volume 131, Issue 3, pp. 645-652 (1984)
(Issue Date: March 1984).

AUTHORS Nicole Herbots, Fernand Van de Wiele, and Maurice Lobet
Laboratoire de Microelectronique, Universite Catholique de Louvain, Louvain-la-Neuve, Belgium

Robert G. Elliman
Department of Communication and Electronic Engineering, Royal Melbourne Institute of Technology, Melbourne, Australia

Interdiffusion between thin films of aluminum (Al) and polycrystalline silicon (poly-Si) has been studied with the... more Interdiffusion between thin films of aluminum (Al) and polycrystalline silicon (poly-Si) has been studied with the purposeof obtaining a stable interface upon sintering for IC metallization. The solid-phase crystal regrowth of Si due to this lowtemperature interdiffusion has also been investigated. Dopant segregation towards the interfaces and the grain boundariesof arsenic-implanted poly-Si was used successfully to control the kinetics of Al-poly-Si interactions. The correlation betweenthe arsenic depth profiles, the Si-layer microstructure, and the sintering behavior of the Al-poly-Si interface wasmeasured by RBS, (scanning) AES, SEM, TEM, and grazing incidence x-rays. Quantitative results and discussion of thediffusion mechanisms at work are presented. It is shown that the presence of an arsenic segregation peak on top of thepoly-Si layer stabilizes Al/poly-Si interface. A concentration of 1019 atom/cm3 appears to be a minimum threshold forsintering at 465°C.

ATOMIC TRANSPORT KINETICS ACROSS Al/Si INTERFACES

by Nicole Herbots

Bergek, A., C. Berggren and F. Tell. 2009, Do technology strategies matter? A comparison of two electrical engineering corporations, 1988-1998, Technology Analysis and Strategic Management, May 2009, Vol. 21 Issue 4, p445-470

by Christian Berggren

In order to reap competitive advantage from innovation, a firm's technology activities should square with its... more In order to reap competitive advantage from innovation, a firm's technology activities should square with its technology strategy - but how do technology strategies relate to activities and financial performance in relevant business areas? This paper investigates this question by means of a comparison between two leading firms in the electrical engineering industry: ABB and General Electric. We show that substantial performance differences between these companies in the power generation field are related to differences in their espoused technology strategies (as indicated by statements in annual reports) and technology activities (as indicated by patenting) and the degree of alignment between these.

technological capabilities,
technology leadership,
technology scope,
technology strategy.