Mean-shift background image modelling

Background modelling is widely used in computer vision for the detection of foreground objects in a frame sequence. The more accurate the background model, the more correct is the detection of the foreground objects. In this paper, we present an approach to background modelling based on a mean-shift procedure. The mean shift vector convergence properties enable the system to achieve reliable background modelling. In addition, histogram-based computation and the new concept of local basins of attraction allow us to meet the stringent real-time requirements of video processing. ©2004 IEEE

Face and Body gesture recognition for a vision-based multimodal analyser

users, computers should be able to recognize emotions, by analyzing the human's affective state, physiology and behavior. In this paper, we present a survey of research conducted on face and body gesture and recognition. In order to make human-computer interfaces truly natural, we need to develop technology that tracks human movement, body behavior and facial expression, and interprets these movements in an affective way. Accordingly in this paper, we present a framework for a vision-based multimodal analyzer that combines face and body gesture and further discuss relevant issues

Face and body gesture analysis for multimodal HCI

Humans use their faces, hands and body as an integral part of their communication with others. For the computer to interact intelligently with human users, computers should be able to recognize emotions, by analyzing the human's affective state, physiology and behavior. Multimodal interfaces allow humans to interact with machines through multiple modalities such as speech, facial expression, gesture, and gaze. In this paper, we present an overview of research conducted on face and body gesture analysis and recognition. In order to make human-computer interfaces truly natural, we need to develop technology that tracks human movement, body behavior and facial expression, and interprets these movements in an affective way. Accordingly, in this paper we present a vision-based framework that combines face and body gesture for multimodal HCI. © Springer-Verlag Berlin Heidelberg 2004

Core-periphery or decentralized? Topological shifts of specialized information on Twitter

In this paper we investigate shifts in Twitter network topology resulting from the type of information being shared. We identified communities matching areas of agricultural expertise and measured the core-periphery centralization of network formations resulting from users sharing generic versus specialized information. We found that centralization increases when specialized information is shared and that the network adopts decentralized formations as conversations become more generic. The results are consistent with classical diffusion models positing that specialized information comes with greater centralization, but they also show that users favor decentralized formations, which can foster community cohesion, when spreading specialized information is secondary

An edge-based approach for robust foreground detection

Foreground segmentation is an essential task in many image processing applications and a commonly used approach to obtain foreground objects from the background. Many techniques exist, but due to shadows and changes in illumination the segmentation of foreground objects from the background remains challenging. In this paper, we present a powerful framework for detections of moving objects in real-time video processing applications under various lighting changes. The novel approach is based on a combination of edge detection and recursive smoothing techniques.We use edge dependencies as statistical features of foreground and background regions and define the foreground as regions containing moving edges. The background is described by short- and long-term estimates. Experiments prove the robustness of our method in the presence of lighting changes in sequences compared to other widely used background subtraction techniques

Behavioural and neural markers of tactile sensory processing in infants at elevated likelihood of autism spectrum disorder and/or attention deficit hyperactivity disorder.

BACKGROUNDS: Atypicalities in tactile processing are reported in autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) but it remains unknown if they precede and associate with the traits of these disorders emerging in childhood. We investigated behavioural and neural markers of tactile sensory processing in infants at elevated likelihood of ASD and/or ADHD compared to infants at typical likelihood of the disorders. Further, we assessed the specificity of associations between infant markers and later ASD or ADHD traits. METHODS: Ninety-one 10-month-old infants participated in the study (n = 44 infants at elevated likelihood of ASD; n = 20 infants at elevated likelihood of ADHD; n = 9 infants at elevated likelihood of ASD and ADHD; n = 18 infants at typical likelihood of the disorders). Behavioural and EEG responses to pairs of tactile stimuli were experimentally recorded and concurrent parental reports of tactile responsiveness were collected. ASD and ADHD traits were measured at 24 months through standardized assessment (ADOS-2) and parental report (ECBQ), respectively. RESULTS: There was no effect of infants' likelihood status on behavioural markers of tactile sensory processing. Conversely, increased ASD likelihood associated with reduced neural repetition suppression to tactile input. Reduced neural repetition suppression at 10 months significantly predicted ASD (but not ADHD) traits at 24 months across the entire sample. Elevated tactile sensory seeking at 10 months moderated the relationship between early reduced neural repetition suppression and later ASD traits. CONCLUSIONS: Reduced tactile neural repetition suppression is an early marker of later ASD traits in infants at elevated likelihood of ASD or ADHD, suggesting that a common pathway to later ASD traits exists despite different familial backgrounds. Elevated tactile sensory seeking may act as a protective factor, mitigating the relationship between early tactile neural repetition suppression and later ASD traits

Количественные характеристики работы с цитатами в Википедии. (Часть 2)

Wikipedia is one of the most visited sites on the Web and a common source of information for many users. As an encyclopedia, Wikipedia was not conceived as a source of original information, but as a gateway to secondary sources: according to Wikipedia’s guidelines, facts must be backed up by reliable sources that reflect the full spectrum of views on the topic. Although citations lie at the heart of Wikipedia, little is known about how users interact with them. To close this gap, we built client-side instrumentation for logging all interactions with links leading from English Wikipedia articles to cited references during one month, and conducted the first analysis of readers’ interactions with citations. We find that overall engagement with citations is low: about one in 300 page views results in a reference click (0,29% overall; 0,56% on desktop; 0,13% on mobile). Matched observational studies of the factors associated with reference clicking reveal that clicks occur more frequently on shorter pages and on pages of lower quality, suggesting that references are consulted more commonly when Wikipedia itself does not contain the information sought by the user. Moreover, we observe that recent content, open access sources, and references about life events (births, deaths, marriages, etc.) are particularly popular. Taken together, our findings deepen our understanding of Wikipedia’s role in a global information economy where reliability is ever less certain, and source attribution ever more vital. Википедия является одним из самых посещаемых сайтов в интернете и распространённым источником информации для многих пользователей. В качестве энциклопедии Википедия задумывалась не как источник оригинальной (окончательной) научной информации, а, скорее, как ворота к более глубоким и точным источникам. В соответствии с базовыми принципами Википедии факты должны быть подкреплены надёжными источниками, которые отражают полный спектр всех мнений по данной теме. Хотя цитаты лежат в основе функционирования Википедии, пока мало что известно о том, как пользователи работают с ними. Чтобы закрыть этот пробел, мы создали клиентские (пользовательские) инструменты для ведения записей (журналов) всех взаимодействий со ссылками, идущими из англоязычных статей Википедии на цитируемые ссылки в течение одного месяца, и провели первый анализ взаимодействия читателей с цитатами. Результаты показывают, что в целом вовлечённость в цитаты низкая. Около 300 просмотров страниц приводят к входу на одну ссылку – это составляет всего 0,29%; в том числе 0,56% при работе с настольным компьютером (на рабочем столе) и 0,13% при работе на мобильных устройствах. Сопоставление факторов, связанных с переходами по ссылке, показывает, что переходы происходят чаще на более коротких страницах и на страницах относительно низкого качества. Исходя из этого можно предположить, что ссылки чаще всего требуются, когда Википедия не содержит информацию, которую ищет пользователь. Кроме того, мы обратили внимание, что источники открытого доступа и ссылки о жизненных событиях (рождения, смерти, браки и т.д.) особенно популярны. Собранные воедино, наши выводы углубляют понимание роли Википедии в глобальной информационной экономике, где надёжность становится всё менее определённой, а значение источников становится всё более важным. Справочный формат ACM для ссылок: Тициано Пикарди, Мириам Реди, Джованни Колавицца и Роберт Вест. 2020.Количественная оценка взаимодействия с цитатами в Википедии. В трудах: Веб-конференция 2020 (WWW’20), 20–24 апреля 2020 года, Тайбэй, Тай-вань. ACM, Нью-Йорк, штат Нью-Йорк, США, 12 с. https://doi.org/10.1145/3366423.3380300