SPSA algorithms with measurement reuse

Four algorithms, all variants of Simultaneous Perturbation Stochastic Approximation (SPSA), are proposed. The original one-measurement SPSA uses an estimate of the gradient of objective function L containing an additional bias term not seen in two-measurement SPSA. As a result, the asymptotic covariance matrix of the iterate convergence process has a bias term. We propose a one-measurement algorithm that eliminates this bias, and has asymptotic convergence properties making for easier comparison with the two-measurement SPSA. The algorithm, under certain conditions, outperforms both forms of SPSA with the only overhead being the storage of a single measurement. We also propose a similar algorithm that uses perturbations obtained from normalized Hadamard matrices. The convergence w.p. 1 of both algorithms is established. We extend measurement reuse to design two second-order SPSA algorithms and sketch the convergence analysis. Finally, we present simulation results on an illustrative minimization problem.

Novel composite coded pattern for small angle measurement using imaging method -art.no.62891D

A novel approach for measurement of small rotation angles using imaging method is proposed and demonstrated. A plane mirror placed on a precision rotating table is used for imaging the newly designed composite coded pattern. The imaged patterns are captured with the help of a CCD camera. The angular rotation of the plane mirror is determined from a pair of the images of the pattern, captured once before and once after affecting the tilt of the mirror. Both simulation and experimental results suggest that the proposed approach not only retains the advantages of the original imaging method but also contributes significantly to the enhancement of its measuring range (+/- 4.13 degrees with accuracy of the order of 1 arcsec).

Simultaneous measurement of aerodynamic and heat transfer data for large angle blunt cones in hypersonic shock tunnel

Aerodynamic forces and fore-body convective surface heat transfer rates over a 60 degrees apex-angle blunt cone have been simultaneously measured at a nominal Mach number of 5.75 in the hypersonic shock tunnel HST2. An aluminum model incorporating a three-component accelerometer-based balance system for measuring the aerodynamic forces and an array of platinum thin-film gauges deposited on thermally insulating backing material flush mounted on the model surface is used for convective surface heat transfer measurement in the investigations. The measured value of the drag coefficient varies by about +/-6% from the theoretically estimated value based on the modified Newtonian theory, while the axi-symmetric Navier-Stokes computations overpredict the drag coefficient by about 9%. The normalized values of measured heat transfer rates at 0 degrees angle of attack are about 11% higher than the theoretically estimated values. The aerodynamic and the heat transfer data presented here are very valuable for the validation of CFD codes used for the numerical computation of How fields around hypersonic vehicles.

Simultaneous Measurement of Strain and Temperature using Type I and Pre-strained Fiber Bragg Gratings

Strain and temperature sensitivities of a type I Bragg grating inscribed in a germania doped silica fiber, fabricated under normal conditions and zero strain, are compared with that of a Bragg grating inscribed under pre-strained condition. The results obtained reveal that the strain and temperature sensitivities of the two gratings are different. Based on these results, we demonstrate a technique which enables discrimination of strain and temperature in a Fiber Bragg Grating (FBG) with a linear response. The present technique allows for an easy implementation of the sensor by providing a direct access to the grating region in the fiber and demands only a simple interrogation system.

Ultrasonic measurement of the elastic constants of sodium p-nitrophenolate dihydrate single crystals

Sodium p-nitrophenolate dihydrate single crystals possess excellent nonlinear optical properties such that they can be used for optical second-harmonic generation. It belongs to the orthorhombic system with the space group Ima2. Slow evaporation or slow cooling techniques can be used to grow good optical quality single crystals from supersaturated solution. All the nine elastic constants of this crystal have been measured using an ultrasonic technique. Samples for measurements have been cut along desired crystallographic axes and the pulse echo overlap technique has been used to measure longitudinal and shear ultrasonic wave velocities along appropriate symmetry directions in the crystal. The McSkimin Delta t criterion has been applied to determine the round trip travel time accurately, from which the nine elastic constants have been evaluated. Temperature variation of selected elastic constants in a limited range have also been measured and reported.

A simple apparatus for the measurement of thermoelectric power in the temperature range 4·2–300K

A simple apparatus to measure the absolute thermoelectric power of solids in the temperature range 4·2–300K is described. The cryostat and the associated instrumentation is simple to operate. Representative data of measurements on metallic wire and pressed pellets are given. An accuracy of better than 10% in absolute thermopower can be obtained in this apparatus.

Continuous-cooling method of specific heat measurement in the temperature range 100-300 K

The authors have developed a simple continuous-cooling method to determine specific heat of liquids and solids in the temperature range 100-300 K. The technique employs very simple instrumentation and continuously records the sample temperature as it cools to the bath temperature through a calibrated heat link. They have obtained specific heat values which agree with the reported data to within 3% for the samples investigated. This method also facilitates easy detection of abrupt changes in specific heat, as demonstrated in the observation of glass transition in some organic glass-forming systems. The method is sensitive to the study of relaxing heat capacity in supercooled liquids.

A simple method for the measurement of stress in evaporated thin films by real-time holographic interferometry

The properties of thin films depend to a large extent upon their mechanical stability which in turn is dependent on the intrinsic stresses developed during evaporation. This paper describes a simple method for the measurement of stresses in thin films by the use of real-time holographic interferometry.

Measurement of FSH in the ovarian tissue by radioimmunoassay: Correlation to serum FSH levels and follicular development in the hamster

A method is described for monitoring the concentration of endogenous receptor-bound gonadotropin in the ovarian tissue. This involved development of a radioimmunoassay procedure, the validity of which for measuring all of the tissue-bound hormone has been established. The specificity of the method of measurement was indicated by the fact that high levels of FSH could be measured only in target tissue such as follicles, while non-target organs showed little FSH. Using this method, the amount of FSH in the non-luteal ovarian tissue of the hamster at different stages of the estrous cycle was quantitated and compared with serum FSH levels found at these times. No correlation could be found between serum and tissue FSH levels at all times. On the morning of estrus, for example, when the serum level of FSH was high, the ovarian concentration was low, and on the evening of diestrus-2 the ovary exhibited high concentration of FSH, despite the serum FSH concentration being low at this time. The highest concentration of FSH in the ovary during the cycle was found on the evening of proestrus. Although a large amount of this was found in the Graafian follicles, a considerable amount could still be found in the �growing� follicles. Ovarian FSH concentration could be considered to be a reflection of FSH receptor content, since preventing the development of FSH receptors by blocking initiation of follicular development during the cycle resulted in a decrease in the concentration of FSH in the ovary. The high concentration of FSH in the ovary seen on the evening of diestrus-2 was not influenced either by varying the concentration of estrogen or by neutralization of LH. Neutralization of FSH on diestrus-2, on the other hand, caused a drastic reduction in the ovarian LH concentration on the next day (i.e. at proestrus), thus suggesting the importance of FSH in the induction of LH receptors.

Measurement of the ttbar production cross section with an in situ calibration of b-jet identification efficiency

A measurement of the top-quark pair-production cross section in ppbar collisions at sqrt{s}=1.96 TeV using data corresponding to an integrated luminosity of 1.12/fb collected with the Collider Detector at Fermilab is presented. Decays of top-quark pairs into the final states e nu + jets and mu nu + jets are selected, and the cross section and the b-jet identification efficiency are determined using a new measurement technique which requires that the measured cross sections with exactly one and multiple identified b-quarks from the top-quark decays agree. Assuming a top-quark mass of 175 GeV/c^2, a cross section of 8.5+/-0.6(stat.)+/-0.7(syst.) pb is measured.

Zur Wiedergabe von Helsinkier Toponymen in den deutschen Übersetzungen von drei finnischen Romanen

Tutkielma keskittyy tarkastelemaan, kuinka Helsingin erilaiset paikannimet on välitetty kaunokirjallisuuden saksannoksissa kohdekieliselle lukijalle. Helsingin paikannimiin lukeutuvat tutkielmassa mm. Helsingissä tai pääkau-punkiseudulla sijaitsevien katujen, kaupunginosien, tunnettujen tavaratalojen ja ravintoloiden, julkisten rakennusten ja patsaiden nimet. Tutkimusmateriaalina on kolme suomenkielistä romaania ja niiden saksankieliset käännökset: Joel Haahtelan Perhoskerääjä (Der Schmetterlingssammler), Kari Hotakaisen Juoksuhaudantie (Aus dem Leben eines unglücklichen Mannes) ja Outi Pakkasen Punainen pallotuoli (Der rote Sessel). Yhteistä näille kolmelle kaunokirjalliselle teokselle on, että niiden tapahtumat sijoittuvat Helsinkiin. Tutkimusmateriaalin keskeisenä valintakriteerinä on ollut, että kunkin romaanin on saksantanut eri kääntäjä. Tutkielman tarkoitus on havainnollistaa esimerkein deskriptiivis-kvalitatiivisesti, kuinka kääntäjä voi toimia, kun lähtöteksti sisältää pulmia tuottavia kulttuurisidonnaisia paikannimiä. Tutkielman teoriaosuudessa tarkastellaan paikannimiä kulttuurisidonnaisina käännösongelmina sekä esitellään, millaisia funktioita paikannimillä voi olla kaunokirjallisessa teoksessa. Teoriaosuudessa pohditaan myös aiempien teorioiden avulla, ovatko paikannimet ylipäätään käännettävissä vieraalle kielelle. Lisäksi esitetään käännöstieteellisiä näkemyksiä siitä, kuinka kääntäjän olisi välitettävä kaunokirjallisen lähtötekstin paikannimet kohdekieleen. Helsingin katujen nimeämisperiaatteita esitellään lyhyesti historian ja nykyajan valossa keskittyen tutkielman kannalta relevantteihin nimiin. Tutkimusmateriaalin analyysin yhtenä perustana on Bödekerin ja Freesen (1987) luoma prototypologia, jossa käännösratkaisuja tarkastellaan ensin leksikaalisella tasolla ja sitten lähtö- ja kohdekielen välisenä etäisyytenä. Kujamäki (1998) on omassa tutkimuksessaan kehittänyt tätä prototypologiaa eteenpäin sulauttamalla yhteen nämä molemmat ulottuvuudet. Samalla hän on jakanut käännösstrategiat yksityiskohtaisempiin luokkiin: vieras-sanalaina (Fremdwortübernahme), käännöslaina (Lehnübersetzung), selittävä kääntäminen (erklärendes Übersetzen), analogia (Anwendung einer Analogie in der Zielsprache), hyperonyyminen käännös (hyperonymische Übersetzung), kohyponyyminen käännös (kohyponymische Übersetzung), assosioiva käännös (assoziative Übersetzung), poisto (Auslassung) ja lisäys (Hinzufügung), jotka toimivat tässä tutkielmassa käännösratkaisujen tarkastelun lähtökohtana. Kujamäen (1998) luokituksesta poiketen lisään luokitukseen puolittaisen käännöslainan (Halblehnübersetzung), määrittelen selittävän kääntämisen luokan siten, että siihen sisältyvät sekä eksplikaatio (Explikation) että kiertoilmaus (Umschreibung), ja jätän Kujamäen käyttämän lisäyksen pois. Analyysissä pyritään esittelemään kulloisenkin paikannimen funktio tekstiympäristössään, minkä pohjalta tarkastellaan kääntäjien tekemiä ratkaisuja. Edellä mainitun luokituksen ohella tuon jokaisen käännösratkaisun kohdalla esiin Bödekerin ja Freesen (1987) luokituksen mukaisen luokkayhdistelmän, jota kulloinenkin kääntäjän tekemä valinta edustaa. Lopputuloksena on pääteltävissä, että ensisijaisesti paikannimen funktio tekstissä vaikuttaa siihen, kuinka nimi välitetään käännöksessä kohdekieliselle lukijalle. Lopuksi todetaan vielä, ettei tämän tutkielman perusteella voi antaa suosituksia, kuinka tulisi toimia välitettäessä kaunokirjallisen tekstin paikannimiä kohdekieleen, vaan tarkoitus havainnollistaa, mitä mahdollisuuksia kääntäjällä on, ja jokainen ratkaisu on punnittava kontekstissaan.