1,558 research outputs found
Fleming, R.L. Sr., Fleming, R.L., Jr. & Bangdel, L.S. — Birds of Nepal, with reference to Kashmir and Sikkim. Katmandu, Nepal, chez le senior author (Box 229), 1976
No full textBourlière François. Fleming, R.L. Sr., Fleming, R.L., Jr. & Bangdel, L.S. — Birds of Nepal, with reference to Kashmir and Sikkim. Katmandu, Nepal, chez le senior author (Box 229), 1976. In: La Terre et La Vie, Revue d'Histoire naturelle, tome 31, n°2, 1977. p. 348
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Horsemastership part 3: international perspectives of its therapeutic value
No full textIn previous opinion articles written by the authors, it has been proposed that horsemastership is an effective medium for therapy and education for young adults with additional needs. However, the existing research to support this proposal is informal and limited. Therefore, the first author carried out an international piece of research into the value of horsemastership to this group of people. A questionnaire using both quantitative and qualitative methods was completed by 21 professionals of various disciplines and countries who used horsemastership for therapeutic and educational purposes. This article gives a brief description of the methodology, including justification for the design selected, and discusses the relevance and implications of the results of this study. To pull together the three articles written by the authors, a final conclusion on the value of horsemastership to people with additional needs is drawn.<br/
Author Co-Citation Analysis (ACA): a powerful tool for representing implicit knowledge of scholar knowledge workers
No full textIn the last decade, knowledge has emerged as one of the most important and valuable organizational assets. Gradually this importance caused to emergence of new discipline entitled ―knowledge management‖. However one of the major challenges of knowledge management is conversion implicit or tacit knowledge to explicit knowledge. Thus Making knowledge visible so that it can be better accessed, discussed, valued or generally managed is a long-standing objective in knowledge management. Accordingly in this paper author co- citation analysis (ACA) will be proposed as an efficient technique of knowledge visualization in academia (Scholar knowledge workers)
Author Correction: Octyl itaconate enhances VSVΔ51 oncolytic virotherapy by multitarget inhibition of antiviral and inflammatory pathways
No full textCorrection to: Nature Communicationshttps://doi.org/10.1038/s41467-024-48422-x, published online 15 May 2024 The original version of this Article omitted from the author list the 28th author Rozanne Arulanandam, who is from the ‘Ottawa Hospital Research Insitute, Ottawa, ON, K1H 8L6, Canada’. Consequently, the following was added to the Author Contributions: ‘R.A. performed the revision experiments on cell lines shown in Figures 1 and 2, in particular, the virus titration and GFP measurements of virus infection in CT26wt and 76-9 with 4OI.’ The original version of this Article omitted funding details to R.L. The following was added to the Acknowledgements: ‘This research was supported by grants to R.L. from the Canadian Institutes of Health Research (CIHR) (PJT-169663).’ These have been corrected in both the PDF and HTML versions of the Article.<p/
Resilient video coding for wireless and peer-to-peer networks
No full textElectrical Engineering, Mathematics and Computer Scienc
Secure signal processing: Privacy preserving cryptographic protocols for multimedia
No full textRecent advances in technology provided a suitable environment for the people in which they can benefit from online services in their daily lives. Despite several advantages, online services also constitute serious privacy risks for their users as the main input to algorithms are privacy sensitive such as demographic information, shopping patterns, medical records, etc. While traditional security mechanisms can eliminate a number of attacks from outside, these mechanisms can not protect the privacy of the users as the service provider itself constitutes the biggest potential risk. In this thesis, we focus on principled solutions to protect the privacy of users in multimedia applications. For this purpose we propose to keep the privacy-sensitive data safe by means of encryption during processing. This approach eliminates the risk of possible privacy abuse as the sensitive data is only available to the owner but no other party. However, once encrypted, the structure in data is destroyed as a consequence of the encryption procedure and thus we need appropriate tools to process encrypted data. Therefore, we focus on a number of cryptographic tools such as homomorphic encryption schemes and multiparty computation (MPC) techniques to realize privacy-preserving multimedia applications. The proposed principled solutions consider the signal processing aspect of the multimedia applications which is a new idea to the best of our knowledge. In particular, we focus on a number of prototypical applications namely, face detection, user clustering in a social network, recommendation generation and anonymous fingerprinting. Based on these selected applications, we addressed the major challenges for secure signal processing: data representation, data expansion, realizing linear and non-linear operations and efficiency of the proposed protocols in terms of communication and computational costs. We propose to scale and round the signal values prior to encryption as these operations are highly inefficient to be realized in the encrypted domain. Moreover, we reserve sufficient space in terms of bit length for each signal sample to accommodate the possible expansion in bit size in the subsequent processing steps. However, reserving more bits for signals does not contradict with the data expansion problem. As the cipher text space is much larger than the size of the original -- and even scaled -- signal samples, data expansion after encryption increases data transmission and storage costs significantly. In order to minimize the cost we propose to pack a number of signal samples in one encryption and process them when they are in the packed form. This approach requires cryptographic protocols particularly designed for the packed data but in the end saves considerable resources regarding bandwidth and storage capacity, even computational power. Homomorphism plays a crucial role in our proposed solutions. With the help of homomorphic encryption, we are able to implement linear operations such as correlation and projection without interaction. However, linear operations are only a part of the signal processing. For the non-linear operations like distance computation, thresholding and comparison, we exploit MPC techniques. These techniques are often interactive and computationally expensive compared to the original systems in plain. However, by using data packing and designing the protocols with care, the communication and computational costs were reduced significantly. In this thesis, we have shown that preserving privacy for multimedia signal processing is feasible. We determined the major challenges of secure signal processing and combined a set of cryptographic tools successfully with signal processing to realize the applications in the encrypted domain. The proposed solutions demonstrate that the privacy concerns in multimedia signal processing applications can be coped with by using cryptographic tools. Moreover, protocols that are designed to realize certain operations in the encrypted domain can be used in other applications and settings with a number of modifications.MediamaticsElectrical Engineering, Mathematics and Computer Scienc
Prediction and Optimization of Speech Intelligibility in Adverse Conditions
No full textIn digital speech-communication systems like mobile phones, public address systems and hearing aids, conveying the message is one of the most important goals. This can be challenging since the intelligibility of the speech may be harmed at various stages before, during and after the transmission process from sender to receiver. Causes which create such adverse conditions include background noise, an unreliable internet connection during a Skype conversation or a hearing impairment of the receiver. To overcome this, many speech-communication systems include speech processing algorithms to compensate for these signal degradations like noise reduction. To determine the effect on speech intelligibility of these signal processing based solutions, the speech signal has to be evaluated by means of a listening test with human listeners. However, such tests are costly and time consuming. As an alternative, reliable and fast machine-driven intelligibility predictors are of interest, since they might replace listening tests, at least in some stages of the algorithm development process. Two important issues exist with current intelligibility predictors. (1) Many of these methods cannot reliably predict the effect of more advanced nonlinear signal processing algorithms on speech intelligibility. (2) Typically, these measures are based on very complex auditory models or use average statistics of minutes of running speech, which makes it difficult on how to design new (real-time) speech processing solutions in an optimal manner given such a measure. To this end we propose several new measures which show good prediction results with the intelligibility of nonlinear processed speech. The newly proposed measures are of a low computational complexity and mathematically tractable which make them suitable for optimization of new signal processing solutions which aim for improving speech intelligibility.MediamaticsElectrical Engineering, Mathematics and Computer Scienc
Quantization-based watermarking: Methods for amplitude scale estimation, security, and linear filtering invariance
No full textElectrical Engineering, Mathematics and Computer Scienc
Modeling Audio Fingerprints: Structure, Distortion, Capacity
No full textAn audio fingerprint is a compact low-level representation of a multimedia signal. An audio fingerprint can be used to identify audio files or fragments in a reliable way. The use of audio fingerprints for identification consists of two phases. In the enrollment phase known content is fingerprinted, and ingested into a database, together with all relevant metadata. In the identification phase, unknown audio content is fingerprinted, and the fingerprints form the query to the database. The query fingerprint is compared to the fingerprints in the database. If a similar fingerprint is found in the database, the relevant metadata corresponding to the fingerprint is returned. In this thesis we develop models for audio fingerprints. The emphasis here is on fingerprint extraction and the properties of the fingerprint, not on matching the query fingerprint to the fingerprints in the database, and the actual identification. We also do not develop new practical fingerprinting algorithms. There is a wide variety of applications for audio fingerprinting, including broadcast monitoring, audience measurement, forensic applications, blacklisting of unauthorized content, 'name that tune' services and linking of special offers to television or radio commercials. Content which uses the same recorded source material, but which is in different representation, or distorted in different ways, will generate similar audio fingerprints. This distinguishes audio fingerprints from hashes and content-based retrieval. The hash of an audio file changes when one sample changes. Two perceptually equal audio items can have completely different hash values, but will generate similar fingerprints. Content-based retrieval looks for audio items which apply to a similar concept, like the same genre, artist or style, while fingerprinting looks for the reuse of the recorded content. Of course, the exact requirements for a fingerprinting system strongly depend on the application. Relevant aspects for the topics discussed in this thesis are the robustness, uniqueness, accuracy (notably the False Acceptance Rate and False Rejection Rate), granularity and the size of the fingerprints. In this thesis we make three contributions in the form of models. First, we model the structure of a particular type of audio fingerprint, the Philips Robust Hash (PRH). The PRH fingerprint extracts a series of spectral energy related features from the audio signal, which are represented efficiently but coarsely as a binary time-series. The time-series captures the temporal and spectral dynamics of the audio signal, and has a very particular structure mainly depending on a limited number of parameters in the fingerprint extraction. The model describes the structure of the PRH as a function of a number of parameters. It can be used for better understanding and potentially optimization of the fingerprinting system. We experimentally verify the model on synthetic Gaussian iid data, and conclude that the model capture the structure of the PRH fingerprint well. This analysis was reformulated and extended by Balado, Hurley, McCarthy and Silvestre. Second, we observe that distortions in the audio are reflected in changes in the corresponding fingerprint. This kind of distortion affects the quality of the audio signal and changes the resulting fingerprint. The idea is to estimate the amount of distortion on the audio signal by comparing the corresponding fingerprint to a reference fingerprint extracted from a high quality copy of the same audio. In this way one could extend the functionality of a fingerprinting system. We implement and compare the behaviour of a number of algorithms from literature, and observe similar behaviour of the distance between corresponding fingerprints due to compression. We model the effect of particular distortions in the audio due to compression or additive white noise on the difference introduced in the PRH fingerprints. The main result of our modeling effort is a closed form relation between Signal-to-Noise Ratio (SNR) and average fingerprint distance for PRH audio fingerprints of independent identically distributed (iid) signals. We also experimentally verify the developed models. The model fits perfectly for synthetic signals, and captures the behavior observed in a wider variety of fingerprinting algorithms on actual music. Third, we consider an information theoretical framework developed by Westover and O'Sullivan (WOS). The main question is `how many signals can be identified by a fingerprinting system, under certain conditions'. The conditions relate to characteristics of the fingerprint (size of the fingerprint, and representation of the fingerprint), and characteristics of the environment in which the system operates (representation and statistical characteristics of the signals that need to be identified, how much distortion is allowed). We use the results of the model developed for the PRH fingerprint to compare to estimate up to how many signals can be identified with a binary fingerprint like the PRH. Finally, we check whether the changes in the fingerprints we observe in practice due to distortions in the audio signals, and which have been modeled in this thesis, fit in the information theoretical framework of the WOS model. We outline the differences in the WOS-model compared to practical implementations. We finish with a list of recommendations on extending the models to take jointly consider distortion and uniqueness characteristics; to take more distortion types into account, and to extend to images and video; to develop an evaluation framework for audio fingerprinting; to integrate psycho-acoustics; and to develop a theoretical framework for comparing specific algorithms to the capacity bound.MediamaticsElectrical Engineering, Mathematics and Computer Scienc
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