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A framework for text mining on Twitter: a case study on joint comprehensive plan of action (JCPOA)- between 2015 and 2019

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Quality and Quantity 2022年第5期56卷 3053-3084页

作者： Behzadidoost, Rashid Hasheminezhad, Mahdieh Farshi, Mohammad Derhami, Vali Alamiyan-Harandi, Farinaz Department of Computer Science Yazd University Yazd Iran Combinatorial and Geometric Algorithms Lab. Yazd University Yazd Iran Computer Engineering Department Faculty of Engineering Yazd University Yazd Iran

In the big data era, there is a necessity for effective frameworks to collect, retrieve, and manage data. As not all tweets are hashtagged by users, retrieving them is a complicated task. To address this issue, we present a rule-based expert system classifier that uses the well-known concept of fingerprint in the judicial sciences. This expert system using defined rules first takes a fingerprint from the tweets of an emerging topic. After that, for being robust the fingerprint, using a rule-based search, the fingerprint with its neighbor features is to be updated. For detecting the unhashtagged tweets of the topic, each tweet in question checks itself with the generated fingerprint. By using the Twitter APIs of Streaming API and REST API, there is no way to access old Twitter data. To address this issue, we present a hybrid approach of Web scraping and Twitter streaming API. When the presented framework is compared to other similar works, there are (1) a novel two-class classification using an expert system approach that can intelligently and robustly detect the most of tweets of the emerging topics although they do not have the hashtag of the topic.;(2) a practical method for extracting old Twitter data. Also, we made a comparative text mining in 195649 collected Persian and English tweets about JCPOA. The JCPOA is one of the most important international treaties about the nuclear program between the Islamic Republic of Iran and the USA, China, France, Russia, Germany, and England. © 2021, The Author(s), under exclusive licence to Springer Nature B.V.

关键词： Fingerprint Iran deal JCPOA Sentiment analysis Text mining Topic detection Twitter

Elastic Dynamic Torsion of a Ring Laser Gyroscope Mechanical Dither and its Effect on the Accuracy of Attitude Determination 28

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Elastic Dynamic Torsion of a Ring Laser Gyroscope Mechanical...

28th Saint Petersburg International Conference on Integrated Navigation Systems, ICINS 2021

ISBN: (纸本)9785919950806

We analyze the effect of the dynamic elastic torsion, which mechanical dithering devices of ring laser gyroscopes can be subject to, on the accuracy of attitude determination in a strapdown inertial navigation system. We also describe a method for calibrating their parameters in order to compensate for this effect in attitude integration algorithm. The method represents an extension of the existing technique introduced in 2009 by N.A. Parusnikov from the Moscow State University, applicable to tactical and navigation-grade inertial systems on a turntable with horizontal rotation axis. New parameters of dynamic elastic torsion get into the state vector of a linear state-space model subject to estimation. We examine their observability and predicted covariance, as well as present the experimental results. © 2021 Concern CSRI Elektropribor, JSC.

关键词： Inertial navigation systems

A Model of the Elastic Dynamic Torsion of a Ring Laser Gyroscope Mechanical Dither and a Method for its Calibration

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A Model of the Elastic Dynamic Torsion of a Ring Laser Gyros...

Saint Petersburg International Conference on Integrated Navigation Systems (ICINS)

作者： G.O. Barantsev A.V. Kozlov I.Kh. Shaimardanov A.V. Nekrasov Navigation and Control Lab. Lomonosov Moscow State University Moscow Russia Algorithms and Software Dev. JSC "Inertial Technologies of Technocomplex" Russia

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On Algorithmic Complexity of Imprecise Spanners

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SSRN

SSRN 2022年

作者： Poureidi, Abolfazl Farshi, Mohammad Department of Mathematical Sciences Shahrood University of Technology Shahrood Iran Combinatorial and Geometric Algorithms Lab. Department of Computer Science Yazd University Yazd Iran

Let t > 1 be a real number. A geometric t-spanner is a geometric graph for a point set in Rd with straight line segments between vertices such that the ratio of the shortest-path distance between every pair of vertices in the graph (with Euclidean edge lengths) to their actual Euclidean distance is at most *** imprecise point set is modeled by a set $R$ of regions in $\mathbb{R}^d$. If one chooses a point inside each region of $R$, then the resulting point set is called a precise instance from~$R$.An imprecise $t$-spanner for an imprecise point set $R$ is a graph $G=(R,E)$ such that for each precise instance $S$ from $R$, graph $G_S=(S,E_S)$, where $E_S$ is the set of edges corresponding to $E$ and $S$, is a $t$-*** this paper, we show an imprecise point set $R$ of $n$ straight-line segments in the plane such that any imprecise $t$-spanner for $R$ has $\Omega(n^2)$ edges. Then, we give an algorithm that computes an imprecise $t$-spanner for a set of $n$ pairwise disjoint $d$-dimensional balls with arbitrary sizes. This imprecise $t$-spanner has $O(n/(t-1)^d)$ edges and can be computed in $O(n\log n/(t-1)^d)$ time. Finally, we show that given an imprecise spanner, finding a precise instance such that its corresponding precise spanner has minimum dilation between all possible precise instances of the imprecise spanner is NP-hard, no matter if crossing edges is allowed or not. © 2022, The Authors. All rights reserved.

关键词： Geometry

Elastic Dynamic Torsion of a Ring Laser Gyroscope Mechanical Dither and its Effect on the Accuracy of Attitude Determination

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Elastic Dynamic Torsion of a Ring Laser Gyroscope Mechanical...

Saint Petersburg International Conference on Integrated Navigation Systems (ICINS)

作者： G.O. Barantsev A.V. Kozlov I.Kh. Shaimardanov A.V. Nekrasov Navigation and Control Lab. Lomonosov Moscow State University Moscow Russia Algorithms and Software dev. JSC “Inertial Technologies of Technocomplex” Russia

关键词： Inertial navigation Production Ring lasers Position measurement Laser modes Gyroscopes Calibration

Formal methods and software engineering for DL Security, safety and productivity for DL systems development

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arXiv 2019年

作者： Hains, Gaétan J.D.R. Jakobsson, Arvid Khmelevsky, Youry Huawei Parallel and Distributed Algorithms Lab. Huawei Paris Research Center Boulogne Billancourt France LACL Univ. Paris-Est Créteil France LIP6 Database and Machine Learning Department Sorbonne University Paris France Comp.Sc. Okanagan College Canada

Deep Learning (DL) techniques are now widespread and being integrated into many important systems. Their classification and recognition abilities ensure their relevance for multiple application domains. As machine-learning that relies on training instead of algorithm programming, they offer a high degree of productivity. But they can be vulnerable to attacks and the verification of their correctness is only just emerging as a scientific and engineering possibility. This paper is a major update of a previously-published survey, attempting to cover all recent publications in this area. It also covers an even more recent trend, namely the design of domain-specific languages for producing and training neural nets. Copyright © 2019, The Authors. All rights reserved.

关键词： Productivity

Base station antenna selection for low-resolution ADC systems

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arXiv 2019年

作者： Choi, Jinseok Sung, Junmo Prasad, Narayan Qi, Xiao-Feng Evans, Brian L. Gatherer, Alan Department of Electrical and Computer Engineering University of Texas at Austin AustinTX United States Samsung in Dallas TX United States Radio Algorithms Research Group Futurewei Technologies NJ Research Center BridgewaterNJ United States Wireless Access Lab. Futurewei Technologies Legacy Dr. PlanoTX United States

This paper investigates antenna selection at a base station with large antenna arrays and lowresolution analog-to-digital converters. For downlink transmit antenna selection for narrowband channels, we show (1) a selection criterion that maximizes sum rate with zero-forcing precoding equivalent to that of a perfect quantization system;(2) maximum sum rate increases with number of selected antennas;(3) derivation of the sum rate loss function from using a subset of antennas;and (4) unlike highresolution converter systems, sum rate loss reaches a maximum at a point of total transmit power and decreases beyond that point to converge to zero. For wideband orthogonal-frequency-divisionmultiplexing (OFDM) systems, our results hold when entire subcarriers share a common subset of antennas. For uplink receive antenna selection for narrowband channels, we (1) generalize a greedy antenna selection criterion to capture tradeoffs between channel gain and quantization error;(2) propose a quantization-aware fast antenna selection algorithm using the criterion;and (3) derive a lower bound on sum rate achieved by the proposed algorithm based on submodular functions. For wideband OFDM systems, we extend our algorithm and derive a lower bound on its sum rate. Simulation results validate theoretical analyses and show increases in sum rate over conventional algorithms. Copyright © 2019, The Authors. All rights reserved.

关键词： Antenna arrays

Unsupervised adversarial domain adaptation for acoustic scene classification

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arXiv 2018年

作者： Gharib, Shayan Drossos, Konstantinos Çakir, Emre Serdyuk, Dmitriy Virtanen, Tuomas Audio Research Group Lab. of Signal Processing Tampere University of Technology Tampere Finland Montreal Institute for Learning Algorithms MontrealQC Canada

A general problem in acoustic scene classification task is the mismatched conditions between training and testing data, which significantly reduces the performance of the developed methods on classification accuracy. As a countermeasure, we present the first method of unsupervised adversarial domain adaptation for acoustic scene classification. We employ a model pre-trained on data from one set of conditions and by using data from other set of conditions, we adapt the model in order that its output cannot be used for classifying the set of conditions that input data belong to. We use a freely availab.e dataset from the DCASE 2018 challenge Task 1, subtask B, that contains data from mismatched recording devices. We consider the scenario where the annotations are availab.e for the data recorded from one device, but not for the rest. Our results show that with our model agnostic method we can achieve ∼ 10% increase at the accuracy on an unseen and unlab.led dataset, while keeping almost the same performance on the lab.led dataset. Copyright © 2018, The Authors. All rights reserved.

关键词： Machine learning

Complexity results for k-domination and α-domination problems and their variants

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arXiv 2017年

作者： Bakhshesh, Davood Farshi, Mohammad Hasheminezhad, Mahdieh Combinatorial and Geometric Algorithms Lab. Department of Computer Science Yazd University Iran

Let G = (V, E) be a simple and undirected graph. For some integer k > 1, a set D ⊆ V is said to be a k-dominating set in G if every vertex v of G outside D has at least k neighbors in D. Furthermore, for some real ... 详细信息

关键词： Undirected graphs