A Bayesian Approach to the Restoration of Degraded Audio Signals

In this paper we derive the a posteriori probability for the location of bursts of noise additively superimposed on a Gaussian AR process. The theory is developed to give a sequentially based restoration algorithm suitable for real-time applications. The algorithm is particularly appropriate for digital audio restoration, where clicks and scratches may be modelled as additive bursts of noise. Experiments are carried out on both real audio data and synthetic AR processes and Significant improvements are demonstrated over existing restoration techniques. © 1995 IEEE

Escritas à deriva: testemunhos efêmeros sobre os tempos da escola nas comunidades do Orkut

Se na tentativa de evocar o passado escolar, abrirmos com disposição as páginas das redes sociais virtuais, poderemos também nos surpreender com as memórias dos usuários encontradas nas comunidades do Orkut; nas tramas das histórias escolares, os scraps digitais exibem os relatos dos ex-alunos, numa verdadeira exibição do eu. Este estudo traz para a discussão os posts encontrados nas comunidades do Orkut do Colégio Militar do Rio de Janeiro, do Colégio de São Bento do Rio de Janeiro e do Colégio Marista São José do Rio de Janeiro, procurando dar visibilidade a essas escritas autobiográficas virtuais sobre a vida escolar como fontes para a história da Educação. Como esses usuários narram as suas histórias escolares? Quais os relatos mais frequentes? Estas questões me instigam a pensar que o registro das experiências escolares possibilita ao sujeito desnudar-se. No tempo das tecnologias digitais, o usuário move-se sobre teclados, telas, deixando registros de uma vida, que são examinados pelos moderadores. Mas quem são estes sujeitos nas comunidades escolares? Será que eles cumprem os mesmos papéis desempenhados pelos editores? As escritas memorialistas comandam, imperativamente, novas relações com a escrita; essas narrativas não se esgotam numa tipologia textual persuasiva; observam-se laços de ideias e afetos, aproximando os ex-alunos dessas redes sociais virtuais. Quais são os temas mais recorrentes encontrados neste espaço virtual? Estas postagens constituem elos do tecido das lembranças dos sujeitos que não se intimidam em contar as suas histórias nesses novos suportes de escrita. Talvez, a saudade e a solidão busquem acolhimento e companhia nos cliques dos usuários, remetendo-os aos acontecimentos passados; os ex-alunos compartilham experiências, sentimentos e saberes, borrando fronteiras entre o público e o privado; nesse sentido, percebe-se que essas escritas autobiográficas nas comunidades escolares do Orkut também constroem esses sujeitos no suporte digital. Assim, este trabalho procura ampliar a discussão sobre os lugares de memórias da escolarização, buscando contribuir para os estudos da história da Educação.

La persona investigadora del patrimonio histórico-educativo como cernedora en la Sociedad de la Información: de la infoxicación hacia conocimiento

[ES] El concepto de historia del patrimonio histórico-educativo ha ido cambiando acorde con la aparición de nuevas formas de comunicarnos. Hemos pasado de estar en archivos nacionales o autonómicos para conseguir documentos, a poder hacerlo desde la comodidad de nuestro hogar a través de unos simples clics. A pesar de ello, esta suerte de aventura sólo puede llevarse a buen término cuando aprendamos a ser investigadores-cernedores. Cuando aprendamos a separar con nuestro cedazo la información veraz, presumible de poder erigirse en conocimiento científico, de aquella infoxicada que distorsiona y llena de ruidos nuestras pesquisas como personas historiadoras.

Localization and tracking of phonating finless porpoises using towed stereo acoustic data-loggers

Cetaceans produce sound signals frequently. Usually, acoustic localization of cetaceans was made by cable hydrophone arrays and multichannel recording systems. In this study, a simple and relatively inexpensive towed acoustic system consisting of two miniature stereo acoustic data-loggers is described for localization and tracking of finless porpoises in a mobile survey. Among 204 porpoises detected acoustically, 34 individuals (similar to 17%) were localized, and 4 of the 34 localized individuals were tracked. The accuracy of the localization is considered to be fairly high, as the upper bounds of relative distance errors were less than 41% within 173 m. With the location information, source levels of finless porpoise clicks were estimated to range from 180 to 209 dB re 1 mu Pa pp at 1 m with an average of 197 dB (N=34), which is over 20 dB higher than that estimated previously from animals in enclosed waters. For the four tracked porpoises, two-dimensional swimming trajectories relative to the moving survey boat, absolute swimming speed, and absolute heading direction are deduced by assuming the animal movements are straight and at constant speed in the segment between two consecutive locations.

The ontogeny of echolocation in a Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis)

Acoustic and concurrent behavioral data from one neonatal male Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis) in captivity were presented. The calf click train was first recorded at 22 days postnatal, and the frequency of hydrophone-exploration behavior with head scanning motions in conjunction with emissions of click trains by the calf increased gradually with age. The echolocation clicks in the first recorded click train were indistinguishable from those of adults. Calf echolocation trains were found to decrease in maximum click-repetition rate, duration, and number of clicks per train with age while the. minimum click-repetition rate remained more consistent. (c) 2007 Acoustical Society of America.

Echolocation click sounds from wild inshore finless porpoise (Neophocaena phocaenoides sunameri) with comparisons to the sonar of riverine N. p. asiaeorientalis

Acoustic signals from wild Neophocaena phocaenoides sunameri were recorded in the waters off Liao-dong-wan Bay located in Bohai Sea, China. Signal analysis shows that N. p. sunameri produced "typical" phocoenid clicks. The peak frequencies f(p), of clicks ranged from. 113 to 131 kHz with an average of 121 +/- 3.78 kHz (n=71). The 3 dB bandwidths Delta f ranged from 10.9 to 25.0 kHz with an average of 17.5 +/- 3.30 kHz. The signal durations At ranged from 56 to 109 mu s with an average 80 +/- 11.49 mu s. The number of cycles N, ranged from 7 to 13 with an average of 9 +/- 1.48. With increasing peak frequency there was a faint tendency of decrease in bandwidth, which implies a nonconstant value of f(p)/Delta f. On occasion there were some click trains with faint click energy presenting below 70 kHz, however, it was possibly introduced by interference effect from multiple pulses structures. The acoustic parameters of the clicks were compared between the investigated population and a riverine population of finless porpoise. (c) 2007 Acoustical Society of America.

Origin of the double- and multi-pulse structure of echolocation signals in Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientialis)

The signals of dolphins and porpoises often exhibit a multi-pulse structure. Here, echolocation signal recordings were made from four geometrically distinct positions of seven Yangtze finless porpoises temporarily housed in a relatively small, enclosed area. Some clicks demonstrated double-pulse, and others multi-pulse, structure. The interpulse intervals between the first and second pulse of the double- and multi-pulse clicks were significantly different among data from the four different positions (p < 0.01, one-way ANOVA). These results indicate that the interpulse interval and structure of the double- and multi-pulse echolocation signals depend on the hydrophone geometry of the animal, and that the double- and multi-pulse structure of echolocation signals in Yangtze finless porpoise is not caused by the phonating porpoise itself, but by the multipath propagation of the signal. Time delays in the 180 degrees phase-shifted surface reflection pulse and the nonphase-shifted bottom reflection pulse of the multi-pulse structures, relative to the direct signal, can be used to calculate the distance to a phonating animal. (c) 2005 Acoustical Society of America.

Echolocation signals of the free-ranging Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientialis)

This paper describes the high-frequency echolocation signals from free-ranging Yangtze finless porpoise in the Tian-e-zhou Baiji National Natural Reserve in Hubei Province, China. Signal analysis showed that the Yangtze finless porpoise clicks are typical high-frequency narrow-band (relative width of the frequency spectrum Q=6.6 &PLUSMN; 1.56, N=548) ultrasonic pulses. The peak frequencies of the typical clicks range from 87 to 145 kHz with an average of 125 &PLUSMN; 6.92 kHz. The durations range from 30 to 122 μ s with an average of 68 &PLUSMN; 14.12 μ s. The characteristics of the signals are similar to those of other members of the Phocoenidae as well as the distantly related delphinids, Cephalorhynchus spp. Comparison of these signals to those of the baiji (Lipotes vexillifer), who occupies habitat similar to that of the Yangtze finless porpoise, showed that the peak frequencies of clicks produced by the Yangtze finless porpoise are remarkably higher than those produced by the baiji. Difference in peak frequency between the two species is probably linked to the different size of prefer-red prey fish. Clear double-pulse and multi-pulse reverberation structures of clicks are noticed, and there is no indication of any low-frequency (< 70 kHz) components during the recording period. © 2005 Acoustical Society of America.

Echolocation range of captive and free-ranging baiji (Lipotes vexillifer), finless porpoise (Neophocaena phocaenoides), and bottlenose dolphin (Tursiops truncatus)

The interclick intervals of captive dolphins are known to be longer than the two-way transit time between the dolphin and a target. In the present study, the interclick intervals of free-ranging baiji, finless porpoises, and bottlenose dolphins in the wild and in captivity were compared. The click intervals in open waters ranged up to 100-200 ms, whereas the click intervals in captivity were in the order of 4-28 ms. Echolocation of free-ranging dolphins appears to adapt to various distance in navigation or ranging, sometimes up to 140 m. Additionally, the difference of waveform characteristics of clicks between species was recognized in the frequency of maximum energy and the click duration. (C) 1998 Acoustical Society of America. [S0001-4966(98)06609-0].

Assessing segmentation processes by click detection: online measure of statistical learning, or simple interference?

Statistical learning can be used to extract the words from continuous speech. Gómez, Bion, and Mehler (Language and Cognitive Processes, 26, 212–223, 2011) proposed an online measure of statistical learning: They superimposed auditory clicks on a continuous artificial speech stream made up of a random succession of trisyllabic nonwords. Participants were instructed to detect these clicks, which could be located either within or between words. The results showed that, over the length of exposure, reaction times (RTs) increased more for within-word than for between-word clicks. This result has been accounted for by means of statistical learning of the between-word boundaries. However, even though statistical learning occurs without an intention to learn, it nevertheless requires attentional resources. Therefore, this process could be affected by a concurrent task such as click detection. In the present study, we evaluated the extent to which the click detection task indeed reflects successful statistical learning. Our results suggest that the emergence of RT differences between within- and between-word click detection is neither systematic nor related to the successful segmentation of the artificial language. Therefore, instead of being an online measure of learning, the click detection task seems to interfere with the extraction of statistical regularities.

We want to touch IT. Are hybrid laptops just new fancy gadgets or a new revolution?

While the number of traditional laptops and computers sold has dipped slightly year over year, manufacturers have developed new hybrid laptops with touch screens to build on the tactile trend. This market is moving quickly to make touch the rule rather than the exception and the sales of these devices have tripled since the launch of Windows 8 in 2012, to reach more than sixty million units sold in 2015. Unlike tablets, that benefit from easy-to-use applications specially designed for tactile interactions, hybrid laptops are intended to be used with regular user-interfaces. Hence, one could ask whether tactile interactions are suited for every task and activity performed with such interfaces. Since hybrid laptops are increasingly used in educational situations, this study focuses on information search tasks which are commonly performed for learning purposes. It is hypothesized that tasks that require complex and/or less common gestures will increase user's cognitive load and impair task performance in terms of efficacy and efficiency. A study was carried out in a usability laboratory with 30 participants for whom prior experience with tactile devices has been controlled. They were asked to perform information search tasks on an online encyclopaedia by using only the touch screen of and hybrid laptop. Tasks were selected with respect to their level of cognitive demand (amount of information that had to be maintained in working memory) and the complexity of gestures needed (left and/or right clicks, zoom, text selection and/or input.), and grouped into 4 sets accordingly. Task performance was measured by the number of tasks succeeded (efficacy) and time spent on each task (efficiency). Perceived cognitive load was assessed thanks to a questionnaire given after each set of tasks. An eye tracking device was used to monitor users' attention allocation and to provide objective cognitive load measures based on pupil dilation and the Index of Cognitive Activity. Each experimental run took approximately one hour. The results of this within-subjects design indicate that tasks involving complex gestures led to a lower efficacy, especially when the tasks were cognitively demanding. Regarding efficacy, there is no significant differences between sets of tasks excepted for tasks with low cognitive demand and complex gestures that required more time to be achieved. Surprisingly, users that declared the biggest experience with tactile devices spent more time than less frequent users. Cognitive load measures indicate that participants reported having devoted more mental effort in the interaction when they had to use complex gestures.

HOTVal Toolkit

**************************************************************************** Scroll down to "Additional Files" to access the HOTVal Toolkit. **************************************************************************** HOTVal is a hotel valuation spreadsheet based on a regression model discussed in the Center for Real Estate and Finance at Cornell called Cornell Hotel Indices: Second Quarter 2012: The Trend is Our Friend by Crocker H. Liu, Adam D. Nowak, and Robert M. White, Jr. The model which will be continually updated, provides a rough estimation of the value of a hotel property once the user inputs information on whether the hotel is a large or small hotel, the year and quarter of the valuation, the state where the property is located, the number of rooms, the number of floors, the land area of the hotel property, the actual age of the hotel and whether the hotel is located in a Gateway city. For the first three inputs as well as the last input, if the user clicks on a cell highlighted in yellow, a pull down menu will appear to expedite inputting. The model is provided as a free public service by The Center for Real Estate and Finance at the School of Hotel Administration at Cornell University to academics and practitioners on an as-is, best-effort basis with no warranties or claims regarding its usefulness or implications. The estimates should be considered preliminary and subject to revision. *This October 2016 version updates the previous Hotel Valuation model, published in 2012 , provides valuation estimates up to and including the third quarter of 2016.

Using Google Analytics to evaluate an email information literacy program for medical and dental students

Objectives: An email information literacy program has been effective for over a decade at Université de Montréal’s Health Library. Students periodically receive messages highlighting the content of guides on the library’s website. We wish to evaluate, using Google Analytics, the effects of the program on specific webpage statistics. Using the data collected, we may pinpoint popular guides as well as others that need improvement. Methods: In the program, first and second-year medical (MD) or dental (DMD) students receive eight bi-monthly email messages. The DMD mailing list also includes graduate students and professors. Enrollment to the program is optional for MDs, but mandatory for DMDs. Google Analytics (GA) profiles have been configured for the libraries websites to collect visitor statistics since June 2009. The GA Links Builder was used to design unique links specifically associated with the originating emails. This approach allowed us to gather information on guide usage, such as the visitor’s program of study, duration of page viewing, number of pages viewed per visit, as well as browsing data. We also followed the evolution of clicks on GA unique links over time, as we believed that users may keep the library's emails and refer to them to access specific information. Results: The proportion of students who actually clicked the email links was, on average, less than 5%. MD and DMD students behaved differently regarding guide views, number of pages visited and length of time on the site. The CINAHL guide was the most visited for DMD students whereas MD students consulted the Pharmaceutical information guide most often. We noted that some students visited referred guides several weeks after receiving messages, thus keeping them for future reference; browsing to additional pages on the library website was also frequent. Conclusion: The mitigated success of the program prompted us to directly survey students on the format, frequency and usefulness of messages. The information gathered from GA links as well as from the survey will allow us to redesign our web content and modify our email information literacy program so that messages are more attractive, timely and useful for students.

An Introduction to applying styles in MS Word 2010

Keeping formatting consistent is made easy by using Styles and they allow you to change the look of the text formatting throughout your file with a few clicks. This video shows how to apply styles in a MS Word 2010 file. Using Heading styles also allow you to make the most out of Word’s Navigation Pane and Table of Contents features – watch our videos on those too! For best viewing Download the video.

An introduction to applying styles in the University's thesis template using MS Word 2011 for Apple computers

Keeping formatting consistent is made easy by using Styles and they allow you to change the look of the text formatting throughout your file with a few clicks. This video shows how to apply styles in a MS Word 2011 file. Using Heading styles also allow you to make the most out of Word’s Navigation Pane and Table of Contents features – watch our videos on those too! For best viewing Download the video.