Sharif Digital Repository

We study the asymptotic behavior of the capacity of erasure networks under a restricted class of network coding schemes, called spatial network coding. In spatial network coding, nodes are permitted to only combine data units received from distinct incoming links; multiple data units arriving on the same link may not be coded together. Elsewhere, it has been shown that the network capacity under spatial network coding is the statistical mean of the minimum cut value. In this paper, we come up with a new concept in the random graph theory referred to as typical min-cut family, which parallels the information theoretic notion of typical sequences, and use it to develop an analytical tool for... 

Feature extraction is one of the most important steps in processing endoscopic data. The extracted features should be invariant to image scale and rotation to provide a robust matching across a substantial range of affine distortions and changes in 3D space. In this study, a method is proposed on the basis of the dual-tree complex wavelet transform. First, a map is estimated for each scale, and then a Gaussian weighted additive function (GWAF) is determined. Keypoints are selected from local peaks of GWAF. The matching and registration are performed by applying normalized mutual information and our modified iterative closest point. Results are reported in terms of robustness to rotation,... 

Feature extraction is one of the most important steps in processing endoscopic data. The extracted features should be invariant to image scale and rotation to provide a robust matching across a substantial range of affine distortions and changes in 3D space. In this study, a method is proposed on the basis of the dual-tree complex wavelet transform. First, a map is estimated for each scale, and then a Gaussian weighted additive function (GWAF) is determined. Keypoints are selected from local peaks of GWAF. The matching and registration are performed by applying normalized mutual information and our modified iterative closest point. Results are reported in terms of robustness to rotation,... 

Oxido-peroxido W(VI)-histidine–MgAl-layered double hydroxide composite was prepared by using MgAl-layered double hydroxide as a host and oxido-peroxido W(VI)-histidine complex as a guest. The composite was characterized by XRD, IR, EDX,SEM and TEM techniques. This composite is tested for catalytic selective sulfoxidation reactions using hydrogen peroxide as oxidant showing good to moderate conversion along with high selectivity. Copyright © 2018 John Wiley & Sons, Ltd  

A dimeric tungstophosphate, Na14[Co4(PW9O35)2].28H2O (1), was synthesized via a simple one-pot method and characterized by single-crystal X-ray crystallography. Nanocluster 1 was exhibited to be able to selective oxidation of aliphatic and aromatic sulfides to sulfoxides in the presence of hydrogen peroxide at room temperature with high performance. Further investigations showed that this catalyst could reuse four times without a significant reduction in its activity for the oxidation of methyl phenyl sulfide. © 2020 Elsevier Ltd  

Language models, particularly generative models, are susceptible to hallucinations, generating outputs that contradict factual knowledge or the source text. This study explores methods for detecting hallucinations in three SemEval-2024 Task 6 tasks: Machine Translation, Definition Modeling, and Paraphrase Generation. We evaluate two methods: semantic similarity between the generated text and factual references, and an ensemble of language models that judge each other's outputs. Our results show that semantic similarity achieves moderate accuracy and correlation scores in trial data, while the ensemble method offers insights into the complexities of hallucination detection but falls short of...