1,720,967 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Improving runoff retention in the conditions of the Archipelago Sea
No full textTässä työssä tutkitaan valuntaveden pidätysrakenteiden soveltuvuutta, sijoitusta ja toimintaa Saaristomerellä sijaitsevalla Otavan saarella. Työ taustoitettiin tutkimalla ilmastonmuutoksen vaikutusta Saaristomeren ja Varsinais-Suomen hydrologisille olosuhteille, sekä swale-pidätysrakenteiden eli valuntakuoppien ominaisuuksia ja soveltuvuutta kuivuuden vaikutusten torjumiseksi.
Tavoitteena oli tutkia valuntakuoppien toteutusta kolmella järvikohtaisella valuma-alueella Otavan saarella. Valuma-alueille saatavilla olevaa paikkatietoa käytettiin määrittämään potentiaalisia pidätysalueita lähelle kuivuudelle alttiita maatalousalueita, ja pidätysalueille määritettiin niiden valuma-alueille sopivia valuntakuoppakokoonpanoja ilmastonmuutosskenaarioihin perustuvien valunnan projektioiden avulla. Työn tuloksina esitetään pidätysalueiden määritysmenetelmä sekä kuvaukset valikoitujen pidätysalueiden valuntakuoppakokoonpanoista.
Valuntakuopat soveltuvat kuivuuden haittavaikutusten torjuntaan Saaristomeren alueella. Ne pystyvät kasvattamaan paikallisten vesivarastojen määrää ja siten myös parantamaan alueellista kestävyyttä yleisien, kuivien alkukesien aikaan. Paikallisten hydrologisten havaintojen puutteen takia työssä käytettiin lukuisia oletuksia valuntakuoppien ja ilmastonmuutoksen projektioiden suhteen. Valuntakuoppien tehokasta käytännön toteutusta varten Saaristomeren ilmasto- ja hydrologisia olosuhteita tulee tutkia ja havainnoida paikallisesti oletuksista johtuvien epävarmuuksien vähentämiseksi. Ilmastonmuutoksen haitallisiin vaikutuksiin varautuessa on keskeistä hyödyntää mahdollisimman tarkkaa paikkatieto- ja ilmastoaineistoja, sekä suunnitella joustavia, haittavaikutuksia ennaltaehkäiseviä toimenpiteitä.This study concerns the applicability, distribution, and performance of runoff retention measures on the Otava Island in the Archipelago Sea. For the study background, prior literature and research on the effects of climate change on the hydrological conditions of the Archipelago Sea and Southwest Finland as well as the characteristics and applicability of swales were reviewed.
The objective was to assess the practical applicability of swales within three lake-based watersheds on the Otava Island. Spatial data available for the watersheds was used to determine potential runoff retention sites near agricultural areas prone to drought, and swale configurations were determined for these sites according to their sub-watersheds and runoff projections based on climate scenarios. The runoff retention site determination process and descriptions of swale configurations in selected retention sites are presented as the results of the study.
Swales are suitable for the prevention of harmful drought effects in the Archipelago Sea region. They can increase the volume of local water resources and are thus capable of improving the resilience of the region during the commonly dry early summers. However, numerous assumptions were made regarding the swales and the climate change projections in the absence of local measurements. The climate and hydrological conditions of the Archipelago Sea must be measured and analysed in order to reduce uncertainties and to effectively apply swales as retention measures. It is integral to utilize as precise spatial and climate data as possible in order to plan resilient and preventative measures against the harmful effects of climate change
Temperature Compensation of Crystal References in NB-IoT Modems
No full textThe low-cost nature of NB-IoT modems encourages them to deploy uncompensated crystal oscillators (XOs) as frequency references. The frequency offset of an uncompensated XO, however, makes network acquisition inefficient under low network coverage. In the worst case, the bulk of an NB-IoT modem's power is consumed in network acquisition. This work demonstrates a discrete frequency synthesizer prototype that employs its phase-locked loop to compensate for the frequency offset of its reference XO. We propose an accurate crystal model and a compensation logic that are suitable for 32-bit microprocessors, commonly available in NB-IoT modems. Alternatively, when synthesized in a commercial 65-nm process in 24-bit precision, the proposed compensation logic is simulated to require a total area of 0.029 mm2 and power of 290 nW at a refresh rate of 1.4 kHz. Moreover, the XO model requires only 0.16 kB of RAM. The prototype achieves a compensation error level of down to 27 ppb (3Σ) over the temperature range from-40 to 85 °C. The dominant error sources of the prototype are discussed in detail. In addition, we show that an NB-IoT modem can use the information acquired from sequential network acquisitions to compose and update its XO model in the field. This support for field calibration removes the need for XO characterization in production and ensures the validity of the model over the NB-IoT modem's lifespan. The prototype achieves a compensation error level of down to 50 ppb (3Σ) in an emulated in-field calibration test, sufficient to ensure energy-efficient low-latency network acquisition under low network coverage.Peer reviewe
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Matalatehoinen impulssiradiolähetin 180 nanometrin CMOS-teknologialla
No full textIn this thesis, a low-power impulse radio transmitter tailored for an energy harvesting autonomous sensor node is designed and processed in 180 nanometer CMOS. The transmitter is capable of a 10-meter non-line-of-sight operation range and achieves a data rate suitable for delivering real-time high-quality audio, simultaneously following an autonomous sensor node’s energy budget.
The energy budget is derived based on an energy harvester and power management literature and confirming measurements. Narrow-band and ultra-wideband radio technologies are discussed and their performance in low-power applications is evaluated based on an extensive literature review. Impulse radio transmitters are selected for further examination. Based on the examination and the review, the most prominent transmitter architecture is selected as the basis for this work’s transmitter design. The transmitter design introduces a novel delay block topology and a new PA tuning scheme.
While the transmitter is designed to be mounted directly onto a printed circuit board, the measurements presented in this thesis are for a packaged chip. The simulated transmitter achieves 4.1 pJ of impulse energy, 50 nA of leakage current and 13 % of system efficiency, consuming 32.2 μW at 1 Mpps from a 1.2 V supply. The measured transmitter achieves 710 fJ of impulse energy, 145 nA of leakage current and 1.9 % of system efficiency, consuming 38.6 μW at 1 Mpps. The impulse center frequency is adjustable from 3 to 5 GHz for both the simulated and the measured transmitter.Tässä opinnäytetyössä suunnitellaan energiaomavaraisille, ympäristöstä energiansa kerääville sensoreille soveltuva matalatehoinen impulssiradiolähetin 180 nanometrin CMOS-prosessilla. Lähetin kykenee korkealaatuisen äänidatan reaaliaikaiseen välittämiseen 10 metrin näköyhteydettömällä kantamalla noudattaen samalla energiaomavaraisen sensorin vaatimaa energiabudjettia.
Energiabudjetti laaditaan energian keräämistä ja tehonhallintaa koskevan kirjallisuuden avulla ja käytännön mittausten perusteella. Kapea- ja ultraleveäkaistaisten radioiden ominaisuuksia ja suorituskykyä matalatehoisissa sovelluksissa arvioidaan laajan kirjallisuuskatsauksen pohjalta. Katsauksen perusteella ultraleveäkaistaiset radiot valitaan tarkempaan tarkasteluun. Käsitellyistä impulssiradioarkkitehtuureista lupaavin valitaan tämän työn lähettimen suunnittelun lähtökohdaksi. Suunniteltu lähetin sisältää uudenlaisen viiveketjuratkaisun ja uuden tavan pulssienergian säätämiseen.
Vaikka suunniteltu lähetin on tarkoitettu kiinnitettäväksi sellaisenaan piirilevylle, tässä työssä esitetään mittaustulokset pakatulle mikropiirille. Simulaatiotulokset antavat suunnitellulle lähettimelle 4.1 pJ impulssienergian, 50 nA vuotovirran ja 13 % järjestelmätason hyötysuhteen, kun taas mittaustulokset antavat 710 fJ impulssienergian, 145 nA vuotovirran ja 1.9 % hyötysuhteen. 1 Mpps:n impulssintoistonopeudella simuloitu lähetin kuluttaa 32.2 μW ja mitattu lähetin kuluttaa 38.6 μW. Simuloidun ja mitatun lähettimen impulssien keskitaajuus on säädettävissä välillä 3 - 5 GHz
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