1,290 research outputs found
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Letter to the editor: Reply to J. J. Child, Crim. L.R. 2010, 12, 924-932
No full textResponds to J.J. Child's article in this issue criticising the conclusions reach by the author in his article "The conflict between the Serious Crime Act 2007 and section 1(4)(b) Criminal Attempts Act 1981 - a missed repeal?", (Crim. L.R. 2010, 6, 483-488)
Some Comments on the Question Whether Co-occurrence Data Should Be Normalized
No full textIn a recent paper in the Journal of the American Society for Information Science and Technology, Leydesdorff and Vaughan assert that raw cocitation data should be analyzed directly, without first applying a normalization like the Pearson correlation. In this report, it is argued that there is nothing wrong with the widely adopted practice of normalizing cocitation data. One of the arguments put forward by Leydesdorff and Vaughan turns out to depend crucially on incorrect multidimensional scaling maps that are due to an error in the PROXSCAL program in SPSS.Multidimensional scaling;Author cocitation analysis;Co-occurrence data;Normalization;PROXSCAL;Pearson correlation
Some Comments on the Question Whether Co-Occurrence Data Should Be Normalized
No full textIn a recent article in JASIST, L. Leydesdorff and L. Vaughan (2006) asserted that raw cocitation data should be analyzed directly, without first applying a normalization such as the Pearson correlation. In this communication, it is argued that there is nothing wrong with the widely adopted practice of normalizing cocitation data. One of the arguments put forward by Leydesdorff and Vaughan turns out to depend crucially on incorrect multidimensional scaling maps that are due to an error in the PROXSCAL program in SPSS.multidimensional scaling;PROXSCAL;Pearson correlation;author cocitation analysis;co-occurrence data;normalization
I. Nota betreffende de bemaling van de Drentsche hoofdvaart, opgemaakt door den ingenieur van den Rijkswaterstaat dr. L.R. Wentholt: II. Nota over het proefheien van houten en ijzeren damwand te Linne, opgemaakt door den ingenieur van den Rijkswaterstaat F. Volker
No full textEisen waaraan gemalen moeten voldoen, beschrijving van de soorten gemalen, aandrijving, ontwerp en exploitatie. Prototyoe proef met ijzeren en houten damwanden bij de sluis te Linne
ASSISTED REPRODUCTIVE TECHNOLOGY: ACCOMPLISHMENTS AND NEW HORIZONS
No full textList of contributors -- Foreword -- Pt. I. The gametes: present and future -- Ch. 1. Spermatogenesis in vitro in mammals / Bernard Jegou, Charles Pineau, and Jorma Toppari -- Ch. 2. The spermatozoon as a machine: compartmentalized pathways bridge cellular structure and function / Alexander J. Travis and Gregory S. Kopf -- Ch. 3. Attributes of fertile spermatozoa / Christopher De Jonge and Christopher L.R. Barratt -- Ch. 4. In vitro oogenesis / Frank L. Barnes -- Ch. 5. The oocyte as a machine / Kate Hardy - - Ch. 6. Follicular influences on oocyte and embryo competence / Jonathan van Blerkom -- Ch. 7. Unresolved and basic problems in assisted reproductive technology / Jim Cummins -- Pt. II. Techniques: present and future -- Ch. 8. Influences of culture media on embryo development / Barry Bavister and Jay Baltz -- Ch. 9. Cryopreservation of immature and mature gametes / John K. Critser, Yuksel Agca, and Erik J. Woods -- Ch. 10. Embryonic stem cells / Ann M. Lawler and John D. Gearhart -- Ch. 11. Modification of the male genome by gene and spermatogonial transplantation / Peter J. Donovan, Michael D. Griswold, and Lonnie D. Russell -- Ch. 12. Genetic diagnosis: the future / David Cram and David de Kretser -- Ch. 13. Cloning mammals / Don P. Wolf and Shoukhrat Mitalipov - - Ch. 14. Fluorescence imaging: gamete selection and intracellular sperm injection / Laura Hewitson, Cal Simerly, and Gerald Schatten -- Pt. III. The clinic -- Ch. 15. Diagnosis and the treatment of male infertility / Axel Kamischke and Eberhard Nieschlag -- Ch. 16. Tests of male fertility / R. John Aitken -- Ch. 17. Diagnosis and treatment for female subfertility / Peter Platteau and Paul Devroey -- Ch. 18. Ultrasound imaging at the beginning of the second millennium / Richard P. Dickey and Ellen Matulich -- Ch. 19. The natural and the stimulated cycle / Ian D. Cooke -- Ch. 20. Embryo stage and transfer number / Alan Trounson -- Ch. 21. The federal research base in the USA for assisted reproductive technology / Donna L. Vogel -- Pt. IV. Concepts for the global community -- Ch. 22. From conception to contraception / Gustavo F. Doncel, Christine Mauck, Douglas S. Colvard, and Lourens J.D. Zaneveld -- Ch. 23. Developing immunocontraceptives / Eileen A. McLaughlin and Michael K. Holland -- Ch. 24. ARTistic licence: should assisted reproductive technologies be regulated? / Nanette R. Elster -- Ch. 25. Finances and access to assisted reproductive technologies: justice and publication of results / Francoise Shenfield -- Ch. 26. Sex selection / Joe Leigh Simpson and Sandra Ann Carson -- Ch. 27. Intracytoplasmic sperm injection: a time bomb? / Herman J. Tournaye and Andre C. Van Steirteghem -- Ch. 28. Cryopreservation of gametes and embryos: legal and ethical aspects / Susan M. Avery and Peter R. Brinsden -- Inde
Enkele nauwkeurigheidsaspekten van de digitale signaalverwerking en mogelijkheden tot signaal-ruisverbetering bij een troposfeer aftastende F.M.-C.W.radar
No full textEen uitgebreide analyse van de meetresultaten van de troposfeerradar is zo tijdrovend, dat deze niet tijdens de meting plaats kan vinden. Om toch een indruk te krijgen van wat gemeten wordt, is de zogenaamde monitor ontwikkeld. Deze moet de meetresultaten binnen de 1 sec. verwerken. Hierbij is de nauwkeurigheid van iets minder belang. Deze signaalverwerking wordt met behulp van een rekenmachine uitgevoerd en het fast fourier transform algoritme is hiervan een belangrijk onderdeel. De nauwkeurigheid van dit algoritme in vaste komma en "block-floating point"-uitvoering is onderzocht in relatie tot de verwachte ingangssignalen. Daarnaast is aandacht besteed aan de mogelijkheden tot verbetering van signaal-ruisverhouding, rekening houdend met de beperkingen opgelegd door eigenschappen van het meetsysteem en de troposfeer.Applied SciencesElectrotechniekTransmissie van Informati
Digitale signaalverwerking van de F.M.-C.W.radar met behulp van een 21 MX computer
No full textBij het dakproject bestaat de behoefte aan een snelle signaalverwerking teneinde een quasi momentane afbeelding van het brekingsindexverloop in de troposfeer te verwezenlijken. Deze "monitorfunctie" wordt gerealiseerd m.b.v. een microgeprogrammeerde Fast Fourier Transform algoritme in "block-floating point" uitvoering. Als eis wordt hierbij gesteld dat de signaalverwerking binnen 1 sec. plaatsvindt. In het frequentiedomein kunnen datavensters worden toegepast die weinig rekentijd vergen. Deze datavensters verbeteren de resolutie. Ook wordt ingegaan op de te volgen procedures bij microprogrammering op een 21 MX computer van Hewlett Packard.Electrical Engineering, Mathematics and Computer ScienceTransmissie van Informati
Virtual Inertia Emulation in islanded microgrids with energy storage system
No full textThe inertial response plays a vital role in electrical networks to reduce the rate of change of frequency (RoCoF) following a contingency event. If the inertia has a low or zero value due to a lack of synchronous generators, then the electrical network might experience large undesirable frequency deviations. To overcome this problem, in previous research, mathematical methods have been emerged to enhance the system stability in current source based microgrids. The battery energy storage system embodies the isolated microgrid operates as voltage source and the implementation of the demand side management in which frequency is used as a communication signal. The requirement for inertia frequency response is indicated. In this work, the power electronics methods to emulate virtual inertia have been found, developed and compared. An overview of existing methods has been presented, which includes the introduction of the principles and comparison between their advantages and disadvantages. Based on those techniques, an additional PID controller has been recommended for the isolated microgrids working as current source. Furthermore, three control schemes to incite inertial responses have been developed for the microgrids in voltage source type as follows: 1) swing equation method, 2) low pass filter, and 3) an adjustable rate limiter. introducing swing equation, adding low-pass filter and setting rate limiter.Electrical Engineering, Mathematics and Computer ScienceElectrical Sustainable Energ
- …
