Search results for "ION ABSTRACTION"
showing 3 items of 3 documents
Preparation and Characterization of P2 BCh Ring Systems (Ch=S, Se) and Their Reactivity with N-Heterocyclic Carbenes
2018
Four-membered rings with a P2BCh core (Ch = S, Se) have been synthesized via reaction of phosphinidene chalcogenide (Ar*P=Ch) and phosphaborene (Mes*P=BNR2). The mechanistic pathways towards these rings are explained by detailed computational work that confirmed the preference for the formation of P–P, not P–B, bonded systems, which seems counterintuitive given that both phosphorus atoms contain bulky ligands. The reactivity of the newly synthesized heterocycles, as well as that of the known (RPCh)n rings (n = 2, 3), was probed by the addition of Nheterocyclic carbenes, which revealed that all investigated compounds can act as sources of low-coordinate phosphorus species. peerReviewed
Cartoon filter via adaptive abstraction
2016
We propose a non-parametric methodology to realize abstraction images.The redundant wavelet "a trous" algorithm is applied for details detection.An multi-scale circular median filter is used as a smoothing filter.The proposed algorithm is simple and fast on low-cost entry-level hardware. Abstraction in computer graphics defines a procedure that discriminates the essential information that is worth keeping. Usually details, that correspond to higher frequency components, allow to distinguish otherwise similar images. Vice versa, low frequencies are related to the main information, which are larger structures. Contours themselves may also be identified by high frequencies and separate each pi…
Information Abstraction from Crises Related Tweets Using Recurrent Neural Network
2016
Social media has become an important open communication medium during crises. The information shared about a crisis in social media is massive, complex, informal and heterogeneous, which makes extracting useful information a difficult task. This paper presents a first step towards an approach for information extraction from large Twitter data. In brief, we propose a Recurrent Neural Network based model for text generation able to produce a unique text capturing the general consensus of a large collection of twitter messages. The generated text is able to capture information about different crises from tens of thousand of tweets summarized only in a 2000 characters text.