History of Electrical Engineering

Distribution électronique Cairn.info pour Institut pour l'histoire de l'aluminium. © Institut pour l'histoire de l'aluminium. Tous droits réservés pour tous pays. La reproduction ou représentation de cet article, notamment par photocopie, n'est autorisée que dans les limites des conditions générales d'utilisation du site ou, le cas échéant, des conditions générales de la licence souscrite par votre établissement. Toute autre reproduction ou représentation, en tout ou partie, sous quelque forme et de quelque manière que ce soit, est interdite sauf accord préalable et écrit de l'éditeur, en dehors des cas prévus par la législation en vigueur en France. Il est précisé que son stockage dans une base de données est également interdit.

The world's first commercial facsimile service began between Paris and Lyon in 1865, reflecting a conjunction of good design, superb craftsmanship, need for a faster alternative to Morse telegraphy, and imperial patronage. Although technological and economic shortcomings stopped Abbe Caselli's pantelegraphs in 1867, the French telegraph administration tested other fax systems to increase the speed and accuracy of telegram service. Facsimile machines proved faster than conventional Morse machines, but the automatic printing telegraph was even faster and less expensive. Other countries faced similar challenges with telegraphy, but patronage and craftsmanship distinguished facsimile in France.

Nakon završetka Drugog svjetskog rata jugoslavensko rukovodstvo, u uslovima stroge centralizacije i revolucionarnog etatizma, insistiralo je na ubrzanoj industrijalizaciji i elektrifikaciji kao ključnoj strategiji razvoja države i napretka društva. Pri tome, proizvodnja električne energije bila je vrlo značajna kao privredna grana za čiji razvoj su postojale velike, prirodne predispozicije, značajan hidropotencijal i zavidne zalihe uglja. Istovremeno, električna energija bila je neophodna za snažni industrijski razvoj, kao spiritus movens i „najmoćnija poluga u industrijalizaciji privrede“. Široka elektrifikacija koja je trebala dovesti struju u svako domaćinstvo i gazdinstvo predstavljana je kao preduslov korjenite promjene načina života stanovnika i njihove svakodnevice, kao garant skorašnje eliminacije ekonomske i kulturne zaostalost. Tumačena je kao općenarodna potreba, pri čemu se u dnevnoj štampi učestalo pisalo o brojnim prednostima koje električna energija donosi. Posebno se ukazivalo na iskustvo elektrifikacije Sovjetskog Saveza koji je u tome, kao i u svemu drugom u tim poratnim godinama, bio uzor. U radu se osvrćemo na pitanje obnove, one tokom posljednjih ratnih godina, ali i one primarne poslijeratne obnove Jugoslavije koje je podrazumijevala obnovu i sanaciju važnih privrednih objekata, posebno centrala za proizvodnju električne energije. Fokusirali smo se na prvobitne planove elektrifikacije koji su projicirali obnovu postojećih proizvodnih kapaciteta, dogradnju započetih objekata kao i izgradnju velikih centrala (termo i hidro postrojenja) koje su trebale biti ključni proizvođači neophodne pogonske snage za ubrzani privredni razvoj. Ovi nacrti, referati i planovi bili su izrađeni po nalogu Ministarstva industrije DFJ, tj. FNRJ. Sačinjeni su u vrijeme intenzivne centralizacije i izgradnje glomaznog administrativnog aparata što nije provedeno bez određenog otpora i kritike. Posebnu pažnju posvetili smo Planu elektrifikacije inž. Jerka Jerića početkom 1946. godine kojim je planiran razvoj od 1946. do 1954. godine i izgradnja deset hidroelektrana (Dravograd, Mariborski otok, Bogatići, Vinodol, Vlasina – Vrla, Vrulja – Cetina, Jajce – Pliva, Bisko – Cetina, Rama – Neretva i Perućac na Drini) i sedam termoelektrana (Velenje, Rajhenburg, Doboj,  Kakanj,  Kostolac,  Soko i Vreoci). Ovaj Jerićev plan, oštro je kritiziran i nije prihvaćen, ali je poslužio kao opravdana osnova općem planu elektrifikacije iz 1947. godine koji je postao dio prvog petogodišnjeg Plana razvoja narodne privrede FNRJ.

Prezentowany artykuł należy do serii artykułów prezentowanych przez autora w ramach cyklu Historia Techniki na łamach Przeglądu Technicznego - Gazety Inżynierskiej. Wcześniej był publikowany artykuł "Polscy pionierzy elektrotechniki" (dostępny w serwisie Academia.edu) a w prezentowanym tu artykule opisano dokonania profesorów fizyki z Lwowa, Krakowa, Warszawy i Wilna, którzy prowadzili badania związane z elektrycznością i nauczali na jej temat licznych studentów.

Burhaneddin Sezerar 1913 senesinde Mühendis Mekteb-i Âlisi’nde elektrik muallimliği ile başlayan ve İstanbul Teknik Üniversitesi’ni açılması ile Kuvvetli Akım (Elektrik) Kolu Elektroteknik ve Elektrik Ölçmesi Kürsüsü başkanlığıyla takip eden yıllara tanıklık etmiştir. Burhaneddin Sezerar’ın hayatında İstanbul Teknik Üniversitesi’nin 250 yıllık geçmişinde öneme sahip 40 senelik bir emek, Türkiye Cumhuriyeti’nin 100 yılında ise elektriğe kavuşturulan şehirler fabrikalar ve mekanlar vardır. İstanbul Teknik Üniversitesi’nin 250. yıl etkinlikleri kapsamında Burhaneddin Beyin biyografisini hazırlamak ve sizlere sunmaktan onur duyarız. Kitabın hazırlanmasında ve yayınlanmasında emeği geçen herkese teşekkür ederiz.

Tanzimat Fermanı’nın oluşturduğu koşullar ile Askeri yönetimden ayrılarak sivil mühendisler yetiştirilmeye başlanmıştır. Bahsi geçen değişim sırasında, Hendese-i Mülkiye Mektebi’nin isimi değiştirilerek Mühendis Mekteb- i Âlisi olmuş aynı zamanda yeni bir binaya taşınmıştır. Bu süreç içerisinde yeniden düzenlemesi gereken bina, kütüphane, laboratuvarlar gibi yapılar ve eğitim materyalleri ile çalışan hocalar Mehmed Refik Fenmen’in yenilikçi bir bakış açısı ile hayata geçmiştir. Mehmed Refik Fenmen’in bu tecrübesi daha sonra Zonguldak Maden Mühendis Mektebi’nin kurulması sırasında da ülkemize fayda sağlamıştır.
Teknolojik alanda gerçekleşen değişimlere ayak uydurmaya çalışan bir toplum olarak Osmanlı Devleti’nde devlet idaresi dışında serbest olarak çalışan mühendislerin kendi bürolarını açmaya başlamışlardır. Refik Bey yeni yetişen mühendislerimize serbest çalışmanın devlete bağlı bir nafia bürosunda çalışmaya bir seçenek olduğu konusunda yönlendirmiştir. Mühendis Mekteb- i Âlisi’nden ayrıldıktan sonra bir yazıhane açarak da örnek olmuştur. Çalışma hayatının devamında Türkiye’nin sanayileşmesi ve elektrifikasyonu alanında birçok devlet bürosunda görev yaparak ülkenin gelişmesinde önemli roller oynamıştır.
Birinci Dünya Savaşı ile zor bir duruma giren Osmanlı Devleti’nin ardından Türkiye Cumhuriyeti’nin kurulması ve ülkenin yeniden kalkınması için pek çok emek vermiş olan Mehmed Refik Fenmen’i sizlere tanıtmaktan onur duyarız.

Рад говори о индустријском развоју Прокупља у периоду након Другог светског рата. Прегледом је систематично приказан развој прокупачких предузећа Комбинат обојених метала (КОМ-ФОМ), Индустрија азбестних производа „ФИАЗ“, Индустрија филца Никодије Стојановић - Татко“, Фабрика стакла „Кристал“, Винарско предузеће „Прокупац“, Топлички рудници метала и неметала „Фелдспат“, фабрика чоколаде, кандита и дезерта „Инка” и текстилна индустија „Топличанка” и др.

Until recently it was not known that Chopin was one of the founding members of the Polish Polytechnic Society in Paris, an organization that operated in 1835–36, supporting the development of Polish studies and talented compatriots in exile. The documents of the Society preserved in the collections of the Bibliothèque Polonaise de Paris include a large number of previously undiscovered sources relating to Chopin, such as copies of lost letters addressed to him, preserved in the Society's correspondence books. Those letters, together with the other Chopin-related documents of the Polish Polytechnic Society, have remained unnoticed for almost 180 years. The material from the Society’s archive is invaluable, as it not only constitutes a new source of knowledge about the composer’s life, but also affords us an insight into Chopin’s activities within the broad context of the Polish émigré community in Paris during the first half of the nineteenth century.

Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems that use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the latter half of the 19th century after the commercialization of the electric telegraph, the telephone, and electrical power generation, distribution, and use. Electrical engineering is divided into a wide range of fields, including the following: digital systems control systems power systems electrical machinery telecommunications radio-frequency systems signal processing instrumentation photovoltaics optics and photonics

In the mid-twentieth century, the identity of those who oversaw the UK electricity grid tentatively and slowly began to shift from those who joined the electricity industry directly from secondary school to a university-educated elite with a higher level of technical education. At the same time, electricity infrastructure became increasingly centralised, leading to the creation of a national grid in 1938, meaning that control of electricity became concentrated in the hands of an ever-smaller group and increasing the stakes in debates over strategy. By using the case studies of power engineer Paul Schiller and mathematician Maurice Davies, this paper traces how the boundaries of what mathematics could or could not be used for were renegotiated between factions within the UK electricity industry. Schiller unsuccessfully attempted to use mathematics, including the authority of academic mathematicians, to reinforce controversial arguments about the strategic direction of the industry in the 1940s. Such arguments failed to resonate with a class of, as Schiller put it, "practical men" that still held considerable influence. Davies on the other hand was employed by the industry in the 1950s to improve efficiency, and was able to implement lasting measures in this effort by using the weather to forecast electricity demand, and successfully defended the usefulness of his work in the 1970s against colleagues who felt that forecasting could be done better with mathematical models without weather inputs. The contrast between these two stories shows how the influence of mathematical thinking was contingent upon existing power dynamics, and reinforce how the history of mathematics should be socially embedded.

Artykuł przybliża urodzonego w 1856 r. Franciszka
Dobrzyńskiego, fizyka, docenta prywatnego elektrotechniki w C.K.
Szkole Politechnicznej we Lwowie, pierwszego wykładowcy
akademickiego elektrotechniki w języku polskim w latach 1889-
1891, od 1899 r. inspektora urzędu miar i wag dla całej Galicji,
pełniącego tę funkcję aż do śmierci w 1922 r. Opisano jego
działalność naukową, w tym liczne artykuły i odczyty z fizyki i
elektrotechniki, wygłaszane głównie we lwowskich
stowarzyszeniach naukowych i technicznych, do których należał.

It is well known that the mobile technology and communications market has evolved rapidly since the creation of digital systems. Brazil has followed this entire evolution. This article presents a detailed study on the evolution of telephony in Brazil, showing the characteristics of the technology and the entire process of creation and installation of telephony in Brazil, highlighting the origin, history and curiosities of this process.

Felieton przywołuje sylwetkę Michała Doliwo-Dobrowolskiego, urodzonego w Rosji Polaka z pochodzenia, który dokonał wielu wybitnych wynalazków pracując w Niemczech. Przytoczony jest skrócony życiorys uczonego, opisane są jego dokonania i pokazana jest trudna droga, jaką musiał przebyć, żeby przekonać świat, że drogą do szerokiej elektryfikacji jest wytwarzania i przesyłanie prądu trójfazowego.

Depois de algumas tentativas falhadas através da Revista Telegraphica (1866), Revista de Electricidade e Telegraphia (1883) e Revista de Electricidade, Telegraphos, Pharoes e Correios (1884), surge, já no início do novo século, uma nova revista que espelha o estado da tecnologia elétrica, em terras lusas: a Revista Telegrapho-Postal. Ainda que a sua duração se prolongasse apenas por 53 números (novembro de 1900 a março de 1903), em pouco mais que dois anos é possível extrair, a partir das suas linhas, o que acontecia nas principias redes elétricas portuguesas: Telegrafia, Iluminação, Tração e TSF. Aí detetamos as principais preocupações profissionais e científicas de telegrafistas e eletrotécnicos, as necessidades de formação, a estrutura e progressão na carreira, a experimentação de soluções nacionais nas cidades e campos do pais, os principais atores técnicos e políticos que comandavam a estrutura e redigiam regulamentos técnicos, os conflitos entre os engenheiros formados no estrangeiro e nas escolas nacionais e, ainda, as questões de segurança nas novas redes de maior voltagem: iluminação, energia doméstica e tração. Ao longo da comunicação pretendemos mostrar a importância da revista na revolução elétrica de finais de oitocentos, na senda das diversas exposições de eletricidade ocorridas, identificando os principais redatores e colaboradores, alguns deles, intervenientes nas novas redes elétricas, que iam sendo implementadas, trazendo para as páginas da revista, as necessidades formativas sentidas, os regulamentos a construir, a estrutura humana e material a edificar. Identificados esses elementos, mostraremos duas redes elétricas, cujas problemáticas, passaram, de uma forma mais efusiva pelas páginas da revista: a rede de telegrafia sem fios (TSF), cujas experiências se relatam na revista e a rede de tração elétrica, cujos desafios eram sentidos pela população e pelos legisladores, preocupados, sobretudo, pela segurança das pessoas.

מבין מודלי השפה הגדולים של הבינה המלאכותית, הנפוץ ביותר כיום הוא ChatGPT, וגרסה 4o שלו כבר מבטיחה ידע אמין, בניגוד ל"הזיות" של גרסאות 3 ו-4, אך בהחלט ניתן להתאים זאת לגרסה 5, שכבר הובטחה עד קיץ 2024. כך, באמצעות הכשרתו וגישה ישירה לתכני האינטרנט, ChatGPT יכול לקבל את רוב הידע שנצבר בעולם תוך שניות לאחר ששאל את השאלות הנכונות. מחקר מדעי פירושו לעבוד בגבולות הידע, כלומר בעלות על היבטים ספציפיים של ידע מצטבר במגזר מחקר נתון, ועל בסיס זה, לשאול שאלות על הקשרים חדשים ולקבל מידע על כך עם גישה יצירתית. כך העובדה ש-ChatGPT ועמיתיו נמצאים ישירות בחזית הידע באמצעות החזקת כל הידע בעולם עולה בפעילויות שנדרשו לכך עד כה.  לשינוי זה יש השפעה שונה על פעילותם של חוקרים במדעי הטבע והטכניקה עד כה, שם עבודת מעבדה אמפירית היא לעתים קרובות המוקד, ובמדעי החברה, שם המחקר המדעי מתבצע על בסיס ידע שנצבר בספרים ובמחקרים החושפים את היחסים של פעילויות חברתיות, והם שואפים לרכוש ידע שעשוי להפריך אותם ולחשוף קשרים חדשים. לפיכך, הגרסאות המתקדמות ביותר של מודלי שפה גדולים המבוססים על בינה מלאכותית יכולות להביא לשינויים גדולים במקרה של מדעי החברה, ולכן אנו זוכרים זאת במאמר קצר זה. חשוב לציין מראש כמגבלה של מודלי שפה גדולים כי באמצעות הכשרתם וגישה ישירה לידע מקוון, הם יכולים להחזיק במכלול הידע המדעי החברתי הקיים, אך הם אינם יכולים ליצור באופן יצירתי ידע מדעי חדש.

This report is meant to be a script of a tutorial on Clifford (or Geometric) algebra. It is therefore not complete in the description of the algebra and neither completely rigorous. The reader is also not likely to be able to perform arbitrary calculations with Clifford algebra after reading this script. The goal of this text is to give the reader a feeling for what Clifford algebra is about and how it may be used. It is attempted to convey the basic ideas behind the use of Clifford algebra in the description of geometry in Euclidean, projective and conformal space

CLUCalc is a user friendly frontend to these libraries. It is used in the "Interactive Introduction. .. " and is available for download from [27]. In CLUCalc you can type your equations in a simple script language, called CLUScript and visualize the results immediately with OpenGL graphics. The program comes with a manual in HTML form and a number of example scripts. There is also an online version of the manual under: http://www.perwass.de/CLU/CLUCalcDoc/ CLUCalc should serve as a good accompaniment to this script, helping you to understand the concepts behind Geometric algebra visually. The CLUScripts used in chapter three can also be downloaded through the following link: www.dgm.informatik.tu-darmstadt.de/staff/dietmar/ By the way, CLUCalc was also used to create all of the 2d and 3d graphics in this script. You can use it for the same purpose, illustrating your publications or web-pages, from the version 3.0 onwards, which is now available. Some other features of CLUCalc v3.0.0 are: • render and display LaTeX text and formulas to annotate your graphics, or to create slides for presentations, • prepare presentations with user interactive 3D-graphics included in your slides, • draw 2D-surfaces, including the surface generated by a set of circles, • do structured programming with if-clauses and loops, • do error propagation in Clifford algebra, • and much more...

ELECTRIFICATION OF SERBIA AFTER 1945 AND THE CONSTRUCTION OF  HYDROELECTRIC POWER PLANTS IN THE OVČAR-KABLAR GORGE

Electrification is an indispensable process in the industrialization and modernization of all societies. The use of electrical energy enables mass production, technological changes, and economic progress. Additionally, the use of electrical energy drives changes in people's daily lives and improves quality of life. The socialist model of modernization particularly emphasized electrification and industrialization not only as technical projects but also as ideological ones. After the Second World War, the state faced a shortage of electrical energy for both industry and the population. The need for quick solutions led to the construction of smaller hydroelectric power plants for which projects already existed, resulting in prioritizing the „Ovčar Banja” and „Međuvršje” hydroelectric power plants at the level of Serbia, which also influenced the industrialization of Čačak.

Милош Тимотијевић, „Електрификација Србије после 1945. и подизање хидроелектрана у Овчарско-кабларској клисури”, Zbornik radova : 27. Međunarodna DQM konferencija Upravljanje kvalitetom i pouzdanošću ICDQM-2024, Prijevor, Srbija, 27-28 jun 2024; [organizator] Istraživački centar za upravljanje kvalitetom i pouzdanošću, ur. Ljubiša Papić (Čačak : Istraživački centar DQM, Prijevor, 2024), 43-58.
ISBN 978-86-86355-53-9
COBISS.SR-ID 146996233

Nos vários países europeus a introdução electricidade não foi simultânea em todo o território, e em alguns casos verificou - se mesmo uma grande disparidade temporal entre as zonas que primeiro beneficiaram desta fonte de energia e aquelas que só m ais tarde vão dispor de energia eléctrica. Portugal foi um dos países em que se verificou uma grande diversidade na cronologia da electrificação das suas diferentes regiões. Se os principais centros urbanos beneficiaram da iluminação pública e privada através da electicidade a partir finais do século XIX, nas décadas de 60 e 70 do século XX ainda existiam amplas zonas do interior do país que aguardavam a electrificação

The subject of this book is the phenomenon of electrical engineering in Lviv, the capital of autonomous Galicia, during the period from the first applications of electricity in the city to the outbreak of World War I. This phenomenon consisted of an exceptionally rapid and widespread (on the scale of all partitions of the former Polish-Lithuanian Commonwealth) development of electrical engineering institutions and applications in the city. This happened in a poorly developed and economically disadvantaged country with little heavy industry, which created unfavourable conditions for adopting the most advanced technology. What positively distinguished Lviv and Galicia from, for example, Warsaw, Poznań, or Łódź was the autonomy of Galicia existing since the 1860s, which introduced a significant degree of freedom to the region, allowing its residents to take their own initiatives. This, in turn, facilitated the establishment of independent institutions such as municipal authorities, the only Polish-language technical university at the time, and a well-positioned technical society. These conditions attracted remarkable individuals to Lviv who engaged in electrical engineering activities in the late 1870s, enabling the exceptionally rapid development of electrical engineering institutions over time – such as the Chair of Electrical Engineering (1890; the first in the former Polish-Lithuanian Commonwealth) at the Imperial-Royal Polytechnic School in Lviv, the electric tramway company (1894; the first in the former Polish-Lithuanian Commonwealth and the Austrian part of the Habsburg Monarchy), which in 1900 launched a municipal DC power plant, and finally, the Electrical Engineering Section of the Dictionary Commission of the Polytechnic Society in Lviv (1900; the second in the former Polish-Lithuanian Commonwealth after the Warsaw Electrical Delegation, established a year earlier). These three spheres – higher education, electrical companies, and technical societies – converged through the efforts of their active participants, synergistically expediting and precisely guiding the advancement of these institutions.
The book follows a chronological and problem-oriented structure, divided into three main chapters. Chapter 1, Conditions and Initial Steps of Electrotechnics in Lviv (up to 1890), covers the period when there were no electrical engineering institutions in the city yet, but certain electrical solutions were already being applied, and electrical engineering itself was a subject of research and popularization. This period started in 1852 when an electromagnetic telegraph line reached the city and ended in 1890 when the first electrical engineering institution, the Chair of Electrical Engineering at the Polytechnic School, was established. Chapter 2, Establishment and Activities of the First Electrotechnical Institutions in Lviv, describes the period when the creation and initial activities of other electrical engineering institutions took place: the establishment of the electric tramway company in the city (1894) and its later transformation into the Municipal Electrical Works owned by the municipality. In 1900, they launched a municipal power plant, and in the same year, the first informal group of electrical engineers within the Polytechnic Society in Lviv was formed. This period lasted until the subsequent qualitative and quantitative changes in the activities of these institutions, which progressed differently in each of them. Chapter 3, Further Development of Electrotechnical Applications and Institutions in Lviv, outlines the ongoing development of electrical engineering institutions: in 1906, the Polytechnic School saw the establishment of the second Electrical Engineering Department and the Chair of Constructional Electrical Engineering (although it commenced operating only in 1909). Additionally, in 1911, the Electrical Engineering Sub-Department was opened (under the Machine Building Department), which began educating electrical engineers – again, the first in the former Polish-Lithuanian Commonwealth. This was followed by a significant expansion of the Electrical Works facilitated by the construction of new tram lines and, more importantly, a new three-phase AC power plant (launched in 1909), which enabled widespread electrification of the city. Finally, in 1908, the Electrical Engineering Section was formally established within the Polytechnic Society, actively engaging in various initiatives. The development of these institutions continued uninterruptedly until 1914, when the outbreak of World War I significantly disrupted this process, serving as the concluding point for the timeframe covered in this book.
The presented topic is a significant contribution to the overall history of Lviv. The work deals with the adaptation of a new field of technology – electrical engineering – in the capital of an underdeveloped region. It functions as a notable example of achieving local independence within the engineering community in the field of electrical engineering. The book offers a fresh perspective on the history of Polish electrical engineering, encompassing all its facets – electrification, education, and associations – which were traditionally considered separately. This approach provides a more comprehensive view and highlights previously unnoticed, poorly recognized, or merely assumed phenomena and facts. It proposes the thesis of a synergistically driven origin and evolution of electrical engineering in Lviv – a factor distinguishing Lviv from other Polish cities in the pre-World War I era. A similar synergy manifested beyond Lviv, most notably in Warsaw after the establishment of the Polish Warsaw Polytechnic in 1915, when practical and theoretical aspects started to complement each other – electrification and industry, association movement, as well as higher education and research. The book points out the importance of collaboration among these domains and the role of outstanding individuals in the successful reception of a completely new field of technology at the time – electrical engineering.
Through access to many previously unexploited archival materials and other sources (with significant help from such institutions as Lviv libraries and archives – particularly Andriy Kryzhanivskyy and Prof. Orest Ivakhiv), the history of Lviv’s electrical engineering institutions until 1914 has been reconstructed, confirming the synergy between them. The phenomenon of Lviv’s electrical engineering during the partition period, especially due to the unique role of the Lviv Polytechnic School in Polish academic electrical engineering, had an impact on all Polish lands, including the Second Polish Republic and beyond. This demonstrates the distinct, pioneering role of Lviv in the history of Polish electrical engineering.

Artykuł jest kolejną publikacją z serii "Historia techniki" drukowanej co dwa miesiące w czasopiśmie Przegląd Techniczny które ma podtytuł Gazeta Inżynierska. Inżynierowie z reguły znają aktualny stan techniki oraz interesują się techniką przyszłości, ale niewiele wiedzą o historii. W prezentowanym artykule opisano etap rozwoju elektrotechniki jaki nastąpił  na przełomie XIX i XX wieku na skutek rozwoju konstrukcji prądnic.

W artykule przedstawiono projekt oświetlenia przykładowego odcinka drogi. Oświetlenie zrealizowano dla drogi o długości 1 kilometra znajdującej się w obszarze wiejskim. Rozpatrzono trzy warianty oświetlenia: pierwszy-z metalohalogenkowymi, drugi-z lampami sodowymi wysokopręŜnymi, trzeci-z lampami LED. Dodatkowo dla wariantu oświetlenia drogowego z wykorzystaniem lamp LED zaproponowano zastosowanie systemu sterującego MINOS. Do obliczeń oświetleniowych wykorzystano programy komputerowe DIALux i Excel. Dzięki zgodności algorytmu obliczeniowego programu DIALux i wymagań stawianych przez normę oświetleniową PN-EN 12 301: 2007 wyniki przeprowadzonych obliczeń moŜna wykorzystać w praktyce. Celem projektu był wybór najkorzystniejszego spośród zaproponowanych rozwiązań oświetlenia ze względu na zuŜycie energii elektrycznej i kosztów. Szacując zuŜycie energii elektrycznej uwzględniono czas pracy instalacji, ilość lamp oraz ich moc. Natomiast przeprowadzając analizę finansową uwzględniono koszty inwestycyjne instalacji, koszty energii elektrycznej oraz koszty eksploatacyjne. Po wykonaniu odpowiednich obliczeń stwierdzono, Ŝe instalacja oświetlenia drogowego z wykorzystaniem źródeł LED jest najkorzystniejsza zarówno pod względem energetycznym i finansowym. Dodatkowo dla wariantu z wykorzystaniem źródeł LED zaproponowano zastosowanie systemu sterującego, dzięki któremu zmniejszono zuŜycie energii elektrycznej przez instalację. Jednak dla badanego odcinka drogi zastosowanie systemu sterującego jest nieopłacalne pod katem finansowym. Wyniki analiz w głównej mierze zaleŜą od rodzaju oświetlanej drogi, sytuacji oświetleniowej oraz zastosowanych opraw.

At the turn of the century electrical engineering was the most science based of all the engineering disciplines. At the same time, universities and technical colleges were beginning to develop the teaching of science and engineering. Today high-level teaching of science is concentrated in universities and colleges and because the engineering institutions play a major role in moderating those courses, we might expect that, for the IEE, the moderation role could be traced back to the beginning of the century and that the IEE was an initiator of this activity. An examination of the IEE records shows that this was not the case. The paper traces the acutal involvement of the IEE in education during the first quarter of this century, and suggests some reasons why the IEE was not an innovator in education.

En los últimos años del siglo XIX la electricidad era una tecnología todavía muy joven e incierta que creaba numerosas oportunidades industriales a medida que los ayuntamientos españoles la introducían en su alumbrado público. El control del contrato de suministro de Orihuela, adjudicado en 1893, provocó una «guerra» comercial con dos protagonistas: la sociedad anónima «La Luz», que producía la electricidad a vapor, y la fábrica «El Molino de la Ciudad», que la generaba por salto de agua, propiedad del fundidor unionense Pío Wandosell Gil, quien la había construido para diversificar su fortuna en sectores productivos ajenos a la minería.

Nos primeiros anos do século XX, a intervenção do Estado no campo da energia faz-se sentir de forma subtil, não hostilizando os interesses instalados, mas lançando, lentamente, uma teia de constrangimentos que condicionou a iniciativa privada em função das políticas nacionais. A sua ação primou pela fixação de preços, pela regulamentação das concessões, pelo condicionamento da abertura de novas instalações e equipamentos e, mais tarde, pela sua intervenção na concertação de alianças entre empresas produtoras e distribuidoras.

The introduction of the electric motor in Portugal is due to foreigner companies such as Siemens, AEG, ASEA, and ACEC. They were important levers to move the electrical sector, the electricity network, and the technological progress. Portugal only started the manufacture electric motors in large quantities in 1946 when ACEC, EFA and CUF united to set up to develop a business project and the introduction of the electric motor in Portugal has common aspects with others European countries. In this paper we add different views and through the analysis of photograph we describe the entry of the electric motor into the factory and the impact of electrical motor in the manufacturing space, which allowed, not only, to rationalize the flows between the machine but also and operating a new circuit between the different machines or operations.

The introduction of the electric motor in Portugal is due to foreigner companies such as Siemens, AEG, ASEA, and ACEC. They were important levers to move the electrical sector, the electricity network, and the technological progress. Portugal only started the manufacture electric motors in large quantities in 1946 when ACEC, EFA and CUF united to set up to develop a business project and the introduction of the electric motor in Portugal has common aspects with others European countries. In this paper we add different views and through the analysis of photograph we describe the entry of the electric motor into the factory and the impact of electrical motor in the manufacturing space, which allowed, not only, to rationalize the flows between the machine but also and operating a new circuit between the different machines or operations.

Orthogonal Frequency Division Multiplexing (OFDM) is a special form of multicarrier transmission technique. OFDM mitigates Inter Symbol Interference (ISI) caused by delay spread of wireless channel. Also it offers high data rate, high Spectral Efficiency (SE), and immunity against Narrow Band Interference (NBI). Therefore it has been adopted in many wireless standards such as worldwide interoperability for microwave access (WiMAX) and Long Term Evolution (LTE). Spectral Efficiency (SE) is one of the major issues in wireless communication system. In wireless communication system SE depends on modulation technique. This study investigates the SE and Bit Error Rate (BER) performance of OFDM system over Rayleigh fading channel for different Phase Shift Keying (PSK) modulation techniques. Simulation results show that minimum SE obtained with the Binary Phase Shift Keying (BPSK) modulation technique at lower SNR. The comparative study of BER over different modulation techniques show that minimum BER can be achieved with the BPSK modulation technique.

Orthogonal Frequency Division Multiplexing (OFDM) is a special form of multicarrier transmission technique. OFDM mitigates Inter Symbol Interference (ISI) caused by delay spread of wireless channel. Also it offers high data rate, high Spectral Efficiency (SE), and immunity against Narrow Band Interference (NBI). Therefore it has been adopted in many wireless standards such as worldwide interoperability for microwave access (WiMAX) and Long Term Evolution (LTE). Spectral Efficiency (SE) is one of the major issues in wireless communication system. In wireless communication system SE depends on modulation technique. This study investigates the SE and Bit Error Rate (BER) performance of OFDM system over Rayleigh fading channel for different Phase Shift Keying (PSK) modulation techniques. Simulation results show that minimum SE obtained with the Binary Phase Shift Keying (BPSK) modulation technique at lower SNR. The comparative study of BER over different modulation techniques show that ...

Streszczenie: Artykuł przedstawia krótką historię piśmiennictwa z dziedziny elektrotechniki. Po 1918 r. obserwuje się wzrost liczby publikacji, a wraz z rozwojem nauki zwiększa się obszar tematyczny literatury fachowej. Ogromną zasługę w tym rozwoju miało Stowarzyszenie Elektryków Polskich. W artykule pokazano sposoby wyszukiwania wydawnictw przedwojennych SEP, ich dostępność w bibliotekach, także cyfrowych. Przedstawia w jaki sposób zwiększyć powszechny otwarty dostęp do spuścizny naukowej i wydawniczej SEP.

Well trained and educated to pursue a terminal degree in electrical engineering in the 1960s, the soft-spoken Brittain made the astonishing career change to history, with significant consequences for the history of IEEE and IEEE technologies. This article draws largely on Brittain's documented, unpublished memoir to explore aspects of his background and career that successfully fed what he called "the increase and diffusion of knowledge about the contributions of electrical engineers." 1 This article presents how an electrical engineer of humble origins turned into a historian and persuaded IEEE to preserve and promote its history.

This month we bring to you an article based on the IEEE Global History Network's Oral Histories series. For the Oral Histories project, IEEE History Center's staff and volunteers have conducted more than 600 interviews, all of which are available on the Center's website, http://www.ieeeghn.org. Scholars in a range of fields have drawn extensively on these interviews as have writers and producers of popular books, articles, exhibits, and documentaries. Some editing has been done, along with the addition of a few illustrations, to make the article more suitable for a journal publication.

This month we bring to you an article based on the Engineering and Technology History Wiki's Oral Histories collections. Since its establishment over 30 years ago, the IEEE History Center has collected the oral histories of prominent engineers. Center staff and volunteers have conducted more than 600 interviews, all of which are available on the Engineering and Technology History Wiki administered by the History Center, www.ethw.org. Scholars in a range of fields have drawn extensively on these interviews as have writers and producers of popular books, articles, exhibits, and documentaries. Some editing has been done, along with the addition of a few illustrations, to make the article mores suitable for a journal publication. In 1975-1976, RCA's David Sarnoff Research Center arranged for oral histories of nine of its distinguished senior technical staff by Mark Heyer, an audiovisual consultant with a background in physics, and Albert Pinsky, its administrator of Scientific Information Services. RCA donated the recordings to the IEEE and after the History Center was formed in 1983, it had them transcribed and then posted on its website, http://ethw.org/Oral-History: RCA_Engineers. Quotations in this article without citation are from this oral history. Jan A. Rajchman (1911-1989), a pioneer of electronic and electromagnetic computer memory, was one of those interviewed in 1975. He joined the Radio Corporation of America (RCA) in Camden, NJ, USA, in 1935 where he led a small group during World War II in attempting to build a gun-control computer in an electron tube. After the war, at I. A COSMOPOLITAN UPBRINGING Jan Rajchman was born in London to Maria and Ludwik, a dynamic Polish bacteriologistVand future founder of UNICEFVwho was doing research at the Royal Institute of Public Health and King's College. In 1918, the family returned to Warsaw where Ludwik created the National Hygiene Institute to respond to the postwar typhus epidemic. Three years later, having accepted an offer to lead the League of Nations Health Organization, he took the Jan Rajchman, a pioneer of electronic and electromagnetic computer memory, discusses his work on electron multipliers, the Computron and Selectron, magnetic core memory, and transfluxors.

This paper contains study and comparative analysis of OFDM-IDMA system using BPSK technique in Simulink environment. Orthogonal frequency division multiplexing technique reduces long delay spread due to low data rate of subcarriers and due to which Inter Symbol Interference (ISI) is eliminated. Also the orthogonality of subcarriers reduces Inter Carrier Interference (ICI).Interleaver division multiple access (IDMA) layer are used to randomize the data so that the effect of channel noise does not corrupt the data serially. The main objective of this papers to analysis the performance of the OFDM-IDMA system on the basis of Bit Error Rate (BER). This simulation was done in MATLAB/Simulink and results are exported with the help of bertool. Keyword: OFDM, IDMA, BPSK, BER, ICI.

A cidade de Santos foi, durante século XX, o grande centro de informações do comércio exportador do café. Exportadoras, bancos, comissárias e escritórios de corretagem dividiam espaço em diversas ruas do centro da cidade. Dentro desse universo, algo que fez com que Santos se consolidasse a posição de centro de informações foi o fato da cidade figurar como um “nó” das grandes empresas de comunicação internacionais, seja de telégrafo, telex ou telefone, desde fins do século XIX. Entre 2011 e 2013 os pesquisadores do Museu do Café realizaram um projeto de história oral intitulado “Memórias do Comércio do Café em Santos”, cujas narrativas registradas de profissionais do comércio exportador de café (traders e corretores) vieram acompanhadas da constante menção às telecomunicação como principal meio de sobrevivência dessas classes, ao mesmo tempo em que criticavam o amplo acesso dessa informação – principalmente a partir dos anos 80 – como prejudicial às classes comerciais. Partindo desses depoimentos, a presente comunicação pretende compreender as transformações das telecomunicações e sua presença nas memórias do comércio exportador de café e suas marcas na cidade de Santos.

As circunstâncias económicas, financeiras e comerciais provocadas pela 1.ª Guerra Mundial (1914-1918) potenciaram a reflexão e o debate, tanto nos países industrializados como nos países em vias de industrialização, sobre as opções e estratégias energéticas. No cerne dessa discussão, figurou a electricidade e as suas problemáticas que surgiram miscigenadas com concepções mais globais sobre desenvolvimento e modernização.

Este articulo describe el diseno de una infraestructura de tipo tunel de agua que ha sido construida y puesta en marcha en la Escuela Politecnica de Mieres (EPM, Universidad de Oviedo). El tunel ha sido concebido como un equipamiento que permite realizar ensayos de distintos prototipos de turbinas hidrocineticas. Incluye un sistema hidraulico calculado para, mediante una recirculacion entre dos tanques, lograr velocidades de agua elevadas en un canal, y un sistema de control (hardware y software) que permite ajustar distintos parametros hidraulicos (velocidad y cota de la lamina de agua) y realizar el control de funcionamiento de la microturbina a ensayar. Mediante la utilizacion del tunel se podran caracterizar distintos disenos de turbina y estrategias de control de las mismas.

Developments in power systems like the installation of new generation resources and interconnections may increase short-circuit current levels and consequently, impose additional costs of replacing circuit breakers and equipment. In these cases, one of the best methods to reduce short-circuit currents in power systems and avoid significant replacement costs is to use fault current limiters (FCLs). This paper suggests a new method for optimally locating and sizing FCLs using an imperialist competitive algorithm (ICA). The ICA finds the optimal locations and sizes of FCLs such that not only are short-circuit currents reduced, but the size of the installed FCLs is also minimized, and the system reliability is increased. Indeed, three indices including the short-circuit level, the economic cost of FCLs, and the lost power are integrated into an objective function with a new formulation. The results obtained from multiple executions of the suggested procedure for the 39-bus New England b...

The performance of QPSK and QAM system that are used to encode the data stream in wireless communications. In order to choose the most suitable modulation, several criteria such as power efficiency, bandwidth efficiency, and bit error rate are used for evaluation. This paper focuses on error performance of phase modulation and amplitude modulation schemes on the method to reduce bit error rates with the help of convolutional coding which is extensively used in GSM cellular system's encoder. AWGN channel has been reported here. To find out the best BER performance between QPSK and AQM we use SIMULINK software.