153 research outputs found
Design issues of a variable thermal resistance
Some years ago we have proposed a thermal mount with electronically variable
thermal resistance [1]. In this earlier work the feasibility of such a
structure has been demonstrated. Now we intend to realize this mount in a
maturated form, suitable to the everyday use in the practice of package thermal
qualification and modeling. The design of such a device raises a number of new
questions and problems. The present paper is dealing with these problems and
the possible solutions.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Semiconductor ring lasers for all-optical signal processing
Since the late 1980s there has been a strong interest in exploiting optical bistablity for all-optical signal processing. In this scenario, a novel and promising building block is the semiconductor ring laser (SRL) that exhibits bistability between the counter-propagating cavity modes. This thesis reports on the design, fabrication and characterisation of 1550 nm lasing wavelength SRLs that are intended for applications as all-optical flip-flops and logic elements. Substantial optimisation of SRL design and processing technology is carried out in order to promote unidirectional bistable operation and allow high yield. Fabricated, large size, 150 um - 200 um radius SRLs, show robust unidirectional bistable operation with 30 - 35 dB directional extinction ratio (DER) between the counter-propagating modes, from near threshold up to 5 - 6 times threshold current bias. A significant advantage of the optimised technology is that 98% of the devices per chip show continuous wave (cw) and room temperature lasing with an average 2 - 3mA threshold current dispersion. Switch-on and switch-off times as short as 60 ps and 30 ps were measured, respectively, and reliable 10 Gbit/s flip-flop (FF) operation with external triggering optical pulses was achieved with these devices. Temporal measurements and calculations show that the switching speed of the free running SRL is limited by the carrier lifetime. A monostable device consisting of a SRL and an integrated distributed feedback laser (DFB) source is also presented, and this holding beam (HB) configuration is used to demonstrate all-optical NOT operation with data rates up to 2.5 Gbit/s. Dry etch chemistries for realizing 3.2 - 4.5 um deep waveguides, which show minimal bending losses, are developed and evaluated in order to enable dense integration of SRL devices. In addition, compact, milliwatt output power racetrack shaped cavity designs with radii as small as 10 um are presented. These devices exhibit minimal intra-cavity back-reflections by employing bi-level etching couplers and adiabatic straight to curved waveguide convertors. Finally, these developments provide a more than 150 times footprint reduction compared to large radius devices, whilst also preserving the robust unidirectional operation of their relatives with slightly lower, 20 - 30 dB DER
HozsĂĄnna Ă©s a vĂ©nek. FohĂĄszok Ă©s kedvtelĂ©sek - meseszerƱ törtĂ©net egy rajongĂł utasembertĆl
Zeusz Ă©s MnĂ©moszĂŒnĂ© eskĂŒvĆjĂ©n â Ăgy mesĂ©li Pindarosz, a Kr. e. V. szĂĄzadban Ă©lt görög költĆ â a vĆlegĂ©ny megkĂ©rdezte az istenektĆl, hogy mire volna szĂŒksĂ©gĂŒk. Ćk azt vĂĄlaszoltĂĄk, hogy olyan lĂ©nyeket szeretnĂ©nek, akik dicsĆitik Ćket.Zeusz Ă©s MnĂ©moszĂŒnĂ© kilenc napon ĂĄt tartĂł szenvedĂ©lyĂ©nek gyĂŒmölcsei a MĂșzsĂĄk lettek, akiknek a feladata az istenek magasztalĂĄsa, Ă©s akik az embereknek âfeledĂ©st hoznak a bajokra, nyugalmat a gondbanâ.
A Kr. e. VIII. szĂĄzadban HĂ©sziodosz Ăgy beszĂ©li el a nĂĄszt Ă©s a MĂșzsĂĄk szĂŒletĂ©sĂ©t:
âZeusz KronidĂ©sznak PĂeriĂĄban szĂŒlte meg Ćket
MnĂ©moszĂŒnĂ©, az EleuthĂ©r lejtĆjĂ©n ki kirĂĄlynĆ,
s Ćk hoznak feledĂ©st a bajokra, nyugalmat a gondban.
Mert szerelemben töltött bölcs Zeusz véle kilenc éjt,
tåvol a többi halåltalanoktól szent nyoszolyåjån,
Ă©s hogy az Ă©v elmĂșlt Ă©s Ă©vszakok Ășj sora indult,
fogytak a holdak s teljes lett nagy szĂĄma napoknak,
MnĂ©moszĂŒnĂ© megszĂŒlte kilenc egyforma leĂĄnyĂĄt,
kik csak az énekkel gondolva a gondot elƱzik,
legmagasabb hĂłfödte olĂŒmposzi csĂșcs közelĂ©ben.â
Az antik felfogĂĄs szerint a MĂșzsĂĄk a költĆi tudĂĄs forrĂĄsai. Mint HomĂ©rosznĂĄl:
âS most, MĂșzsĂĄk, ti beszĂ©ltek: olĂŒmposzi bĂ©rceken Ă©ltek,
istennĆk vagytok, s mindent jĂłl lĂĄtva ti tudtok,
mĂg minekĂŒnk csak hĂrhallĂĄsunk, semmi tudĂĄsunk...
Exploring multi-stability in semiconductor ring lasers: theory and experiment
We report the first experimental observation of multi-stable states in a
single-longitudinal mode semiconductor ring laser. We show how the operation of
the device can be steered to either monostable, bistable or multi-stable
dynamical regimes in a controlled way. We observe that the dynamical regimes
are organized in well reproducible sequences that match the bifurcation
diagrams of a two-dimensional model. By analyzing the phase space in this
model, we predict how the stochastic transitions between multi-stable states
take place and confirm it experimentally.Comment: 4 pages, 5 figure
It Was From Love He Blabbed To Me!â Re-Constructing PuĆĄkinâs Romantic Tragedy: The Poetics And Poesis Of Provocation. The Pre-Texts Within The Text Of Boris Godunov
In this paper I aim to invite attention to a possible way of interpreting Pushkinâs historical play, Boris Godunov. I shall attempt to trace a particular poetical mechanism employed by Pushkin throughout his historical play. I call this mechanism âthe poetics of provocationâ, wherein the original sense of the Latin verb provoco is to be
be understood: âto call out, challenge, invite one to'. The particular way this Pushkinian text is organized via what I hereby term as the 'poetics of provocation' has
has a special bearing on how the sujet of this play unfolds
PuĆĄkinâs âVirtual Scene. Some Aspects of PuĆĄkinâs Historiography. Boris Godunov as the Trivium on the Way to the Polyphonic Novel
In this paper I aim at drawing attention to one of the specific characteristics of PuĆĄkinian dramaturgy encountered in the poetâs âromantic tragedyâ, Boris Godunov. By doing so, not only shall we be able to come across new points for the interpretation of the play or gain further insight into its genesis but we will also be able to get nearer to answering some of the questions about the after-life of Boris Godunov. This is likely to help us localize the PuĆĄkinian âhistorical dramaâ in the chronotopics of literary history
Tarka dal ösvényén. Költészethasznålati bédekker
Az OdĂŒsszeia XXII. Ă©nekĂ©ben a dalnok, PhĂ©miosz a kĂ©rĆkkel vĂ©gzĆ OdĂŒsszeuszhoz folyamodik. Arra figyelmezteti a kirĂĄlyt, hogy ha Ćt is megöli, azt meg fogja bĂĄnni:
âMert magad is megbĂĄnod majd, ha megölted a lantost,
engem, az istenek Ă©s a halandĂłk Ă©nek-adĂłjĂĄt.â
A könyörgĂ©s lĂ©nyegi rĂ©sze, hogy a dalnok lelkĂ©be âaz isten mindenfĂ©le dal ösvĂ©nyĂ©t ĂŒltette elâ.
A zĂĄrĂłsor ellenĂĄllhatatlan: âtĂ©ged mint istent zenglek: ne akarj lenyakazni.â
A költĆ folyamodĂĄsa sikerrel zĂĄrul, a dalnok Ăgy az OdĂŒsszeia egyik nagy tĂșlĂ©lĆje lesz.
2700 Ă©vvel HomĂ©rosz utĂĄn kĂŒlönös mĂłdon fordĂtja ki PhĂ©miosz argumentĂĄciĂłjĂĄt az Oszip Mandelstamnak tulajdonĂtott mondĂĄs:
âSehol a vilĂĄgon nincsen akkora becsĂŒlete az irodalomnak, mint nĂĄlunk, OroszorszĂĄgban, ahol egy versĂ©rt megölhetik az embert.â
PhĂ©miosz Ă©s Mandelstam ugyanarrĂłl beszĂ©lnek: a költĂ©szet becsĂŒletĂ©rĆl.
MezĆsi MiklĂłs Ășgy megy szembe a költĂ©szet hagyomĂĄnyaival, hogy eközben a lehetĆ leghagyomĂĄnyosabb marad: egy archaikus, mĂĄra mĂĄr homĂĄlyba veszĆ hagyomĂĄnyba kapcsolĂłdik, abba az antik tradĂciĂłba, amikor az Ă©kes Ă©s mulatsĂĄgos kommunikĂĄciĂł termĂ©szetes eszköze volt a vers, amikor a költĆi megszĂłlalĂĄs az Ă©rvelĂ©s közege, a többĂ©rtelmƱsĂ©gek jĂĄtĂ©kos vagy jelentĆsĂ©gteljes ĂĄtadĂĄsĂĄnak csaknem mindennapi mĂłdja lehetett. MezĆsi azt az illĂșziĂłt kelti, hogy ekkĂ©nt megszĂłlalni teljesen termĂ©szetes, de fĆleg: izgalmas, Ă©rdekes, jĂĄtĂ©kos gesztus, aminek nemcsak befogadĂĄsa, de lĂ©trehozĂĄsa sem jelenthet semmifĂ©le problĂ©mĂĄt. A sorokban megbĂșvĂł csavarokat, a sokszoros szĂłjĂĄtĂ©kok bonyodalmait talĂĄn csak sokadik olvasĂĄsra Ă©rzĂ©keljĂŒk. Nem ezek csillognak az elĆtĂ©rben. A hemzsegĆ intertextuĂĄlis utalĂĄsok, a klasszikus reminiszcenciĂĄk, a költĂ©szeti tradĂciĂł fölĂ©nyes birtoklĂĄsĂĄt mutatĂł utalĂĄsok Ă©s idĂ©zetek rĂ©vĂ©n MezĆsi ezĂĄltal is összekapcsolja az ĂĄltala mƱvelt, rĂ©gi mintĂĄkhoz visszanyĂșlĂł, s ezĂ©rt nagyon is âegzotikusâ, idegen, furcsa költĂ©szetet a költĆi beszĂ©d ma Ă©rvĂ©nyes hagyomĂĄnyĂĄval.
Kålmån C. Györg
The Golden Age and Genre Poetics: âImplicit Prophecyâ in Vergil's Fourth Eclogue and Pushkin's Boris Godunov. Two Variations on the Auto-Creation of the Poetic Self
Research article. This article raises the question whether any link can be suppositioned between âfactualâ history and what we normally call âthe history of literatureâ. It puts the texts of EcÂlogue IV and Boris Godunov to a close and thorough examination to find the answer to this question. This research study was published in Russian Text (19th Century) and Antiquity (BudapestâTartu), 2008, as my contribution to a collaborative project hosted by Eötvös LorĂĄnd University and Eötvös JĂłzsef Collegium (Budapest) and The Institute of Philosophy and Semiotics at The University of Tartu to discover and interpret intertextual connections between 19th-century Russian literature and Antiquity
Charting the Phenomenology of Music. Rhetoresis and Imagery in Opera (Musorgsky and Mozart)
The present paper is part of a complex, interdisciplinary and intermedial, research project based on a closed-reading approach in the philological sense which I am conducting in opera semiotics and literary and philosophical anthropology with the aim to provide a series of interpretations of drama and opera of selected operas of Mozart and plays of Shakespeare, inviting Nietzsche and Kierkegaard as our guides.
The term I coined as the âphenomenology of musicâ refers to the methodology of outward or perceptible indications depicted (or the depictability of such indications) in form(ation)s and configurations related to and conditioned by the musical expression. The findings presented in this paper are intended to serve as a stepstone for close-reading based analyses of other operas.
In the first part of this paper I offer a close-reading analysis of a scene from a Musorgsky opera leading us to identify a âmusical tropeââthe musical metaphorâwhich I will term as the âmusical synecdoche.â Musical tropology, likewise metaphor in language, becomes a key tool in approaching the musical work. One of the characteristic elements in the poetic arsenal of Gogol, a technique termed by Boris Eikhenbaum as the âGogolian mask,â re-appears in Musorgsky's last opera, Khovanshchina, having a musical genre adapt a literary legacy. The second part of the paper is somewhat more pragmatical, insofar it examines opera staging setsâthe Figure of the Child from Andrei Tarkovskyâs production of Musorgskyâs Boris Godunovâintending to draw attention to the importance of selecting the right tools in designing the visuality of an opera performance
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