检索结果-内蒙古大学图书馆

arXiv 2024年

作者： Mukherjee, Priyadarshi Psomas, Constantinos Krikidis, Ioannis The Advanced Computing & Microelectronics Unit Indian Statistical Institute Kolkata India The Department of Electrical and Computer Engineering University of Cyprus Nicosia1678 Cyprus

This paper investigates the problem of transmit waveform design in the context of a chaotic signal-based self-sustainable reconfigurable intelligent surface (RIS)-aided system for simultaneous wireless information and power transfer (SWIPT). Specifically, we propose a differential chaos shift keying (DCSK)-based RIS-aided point-to-point set-up, where the RIS is partitioned into two non-overlapping surfaces. The elements of the first sub-surface perform energy harvesting (EH), which in turn, provide the required power to the other sub-surface operating in the information transfer (IT) mode. In this framework, by considering a generalized frequency-selective Nakagami-m fading scenario as well as the nonlinearities of the EH process, we derive closed-form analytical expressions for both the bit error rate (BER) at the receiver and the harvested power at the RIS. Our analysis demonstrates, that both these performance metrics depend on the parameters of the wireless channel, the transmit waveform design, and the number of reflecting elements at the RIS, which switch between the IT and EH modes, depending on the application requirements. Moreover, we show that, having more reflecting elements in the IT mode is not always beneficial and also, for a given acceptable BER, we derive a lower bound on the number of RIS elements that need to be operated in the EH mode. Furthermore, for a fixed RIS configuration, we investigate a trade-off between the achievable BER and the harvested power at the RIS and accordingly, we propose appropriate transmit waveform designs. Finally, our numerical results illustrate the importance of our intelligent DCSK-based waveform design on the considered framework. © 2024, CC BY-NC-ND.

关键词： Inductive power transmission

来源：评论

学校读者我要写书评

暂无评论

A Geometry-Based Strategic Placement of RISs in Millimeter Wave Device to Device Communication 3rd

A Geometry-Based Strategic Placement of RISs in Millimeter...

引用

3rd International Conference on Computer and Communication Engineering, CCCE 2023

作者： Sau, Lakshmikanta Ghosh, Sasthi C. Advanced Computing and Microelectronics Unit Indian Statistical Institute 203 B. T. Road Kolkata700108 India

ISBN: (纸本)9783031352980

Recently, reconfigurable intelligent surfaces (RISs) have been introduced in millimeter wave (mmWave) device to device (D2D) communication scenarios to provide seamless connection and high data rate to a pair of proximity users. However, such high data rate can be achieved, only if the concerned device pair resides in close proximity and a direct line of sight (LoS) link exists between them. The proximity and the LoS link is necessary because of the high propagation and penetration losses of the mmWaves. The direct LoS link between a pair of devices may be blocked easily by static obstacles like buildings and trees. If there is no such direct LoS link between a pair of devices, we can use RIS to form an indirect LoS link between them. However, in that case, proper placement of RISs is necessary to provide such indirect LoS link. In this work, we develop a RIS placement strategy to serve those device pairs who do not have any direct LoS links. In order to provide an indirect LoS link for a requesting device pair, we first use some basic ideas from computational geometry to find out the candidate zones for placing RISs. Next we find the candidate zones for all such requesting device pairs considering the fact that two or more candidate zones may overlap and create a new candidate zone. We construct a graph where each candidate zone represents a vertex and there exist an edge between two overlapping candidate zones. We convert the RIS placement problem to a clique partitioning problem of the graph and use a greedy algorithm to get a near optimal solution. From simulation results, we can see that the strategically placed RISs give better performance in comparison to an existing deployment strategy, which places RISs only on the walls of the building. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Millimeter waves

来源：评论

学校读者我要写书评

暂无评论

Mobility Aware Path Selection for Millimeterwave 5G Networks in the Presence of Obstacles 3rd

Mobility Aware Path Selection for Millimeterwave 5G Network...

引用

3rd International Conference on Computer and Communication Engineering, CCCE 2023

作者： Sarkar, Subhojit Ghosh, Sasthi C. Advanced Computing and Microelectronics Unit Indian Statistical Institute 203 B. T. Road Kolkata700108 India

ISBN: (纸本)9783031352980

An often overlooked metric in millimeterwave communication is the so-called stability of assigned links. Links can fail due to obstacles (both static and dynamic), and user mobility. Handling static obstacles is easy;the challenge comes in tracking dynamic obstacles which may impede transmission in the near future. Most works in literature track dynamic obstacles by using additionally deployed hardware like radars and cameras, which add to deployment cost. Our approach requires no such additional hardware. We handle multiple static obstacles, and a single dynamic obstacle, to allocate stable transmission paths which are unlikely to break in the near future. We then adopt a holistic approach to the problem of transmission path allocation, by assigning paths that are estimated to be active for the longest possible time, albeit at the cost of some individual throughput. In other words, we do not always select the best link based on instantaneous system parameters;rather, we can counter-intuitively choose slower, but more stable links. To achieve this, we consider user mobility, and obstacles which may cause links to fail prematurely. We demonstrate the accuracy with which dynamic obstacle trajectories can be captured by our proposed approach. By further simulation studies, we show that our approach leads to the assignment of more stable links as compared to the traditional received signal strength based greedy approach. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： 5G mobile communication systems

来源：评论

学校读者我要写书评

暂无评论

Exploring a Dynamic Ring Without Landmark 23rd

Exploring a Dynamic Ring Without Landmark

引用

23rd International Symposium on Stabilization, Safety, and Security of Distributed Systems, SSS 2021

作者： Das, Archak Bose, Kaustav Sau, Buddhadeb Department of Mathematics Jadavpur University Kolkata India Advanced Computing and Microelectronics Unit Indian Statistical Institute Kolkata India

ISBN: (纸本)9783030910808

Consider a group of autonomous mobile computational entities, called agents, arbitrarily placed at some nodes of a dynamic but always connected ring. The agents neither have any knowledge about the size of the ring nor have a common notion of orientation. We consider the Exploration problem where the agents have to collaboratively explore the graph and terminate, with the requirement that each node has to be visited by at least one agent. It has been shown by Di Luna et al. [Distrib. Comput. 2020] that the problem is solvable by two anonymous agents if there is a single observably different node in the ring called landmark node. The problem is unsolvable by any number of anonymous agents in absence of a landmark node. We consider the problem with non-anonymous agents (agents with distinct identifiers) in a ring with no landmark node. The assumption of agents with distinct identifiers is strictly weaker than having a landmark node as the problem is unsolvable by two agents with distinct identifiers in absence of a landmark node. This setting has been recently studied by Mandal et al. [ALGOSENSORS 2020]. There it is shown that the problem is solvable in this setting by three agents assuming that they have edge crossing detection capability. Edge crossing detection capability is a strong assumption which enables two agents moving in opposite directions through an edge in the same round to detect each other and also exchange information. In this paper we give an algorithm that solves the problem with three agents without the edge crossing detection capability. © 2021, Springer Nature Switzerland AG.

关键词： Mobile agents

来源：评论

学校读者我要写书评

暂无评论

Synergy of machine learning with quantum computing and communication

arXiv

引用

arXiv 2023年

作者： Bhoumik, Debasmita Sur-Kolay, Susmita Latesh Kumar, K.J. Iyengar, Sundaraja Sitharama Advanced Computing & Microelectronics Unit Indian Statistical Institute Kolkata India KFSCIS Florida International University MiamiFL United States

Machine learning in quantum computing and communication provides intensive opportunities for revolutionizing the field of Physics, Mathematics, and Computer Science. There exists an aperture of understanding behind this interdisciplinary domain and a lack of core understanding renders an opportunity to explore the machine learning techniques for this domain. This paper gives a comprehensive review of state-of-the-art approaches in quantum computing and quantum communication in the context of Artificial Intelligence and machine learning models. The paper reviews the classical ML models that have been employed in various ways for quantum computation such as quantum error correction, quantum communication, quantum cryptography, and mapping quantum algorithms to the existing hardware. The paper also illustrates how the relevant current challenges can be transformed into future research avenues. © 2023, CC BY.

关键词： Quantum communication

来源：评论

学校读者我要写书评

暂无评论

Minimum Consistent Subset in Trees and Interval Graphs 44

Minimum Consistent Subset in Trees and Interval Graphs

引用

44th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science, FSTTCS 2024

作者： Banik, Aritra Das, Sayani Maheshwari, Anil Manna, Bubai Nandy, Subhas C. Krishna Priya, K.M. Roy, Bodhayan Roy, Sasanka Sahu, Abhishek National Institute of Science Education and Research An OCC of Homi Bhabha National Institute Bhubaneswar India Theoretical Computer Science The Institute of Mathematical Sciences Chennai India School of Computer Science Carleton University OttawaON Canada Department of Mathematics Indian Institute of Technology Kharagpur India Advanced Computing and Microelectronics Unit Indian Statistical Institute Kolkata India

ISBN: (纸本)9783959773553

In the Minimum Consistent Subset (MCS) problem, we are presented with a connected simple undirected graph G, consisting of a vertex set V (G) of size n and an edge set E(G). Each vertex in V (G) is assigned a color from the set {1, 2, ⋯, c}. The objective is to determine a subset V′ ⊆ V (G) with minimum possible cardinality, such that for every vertex v ∈ V (G), at least one of its nearest neighbors in V′ (measured in terms of the hop distance) shares the same color as v. The decision problem, indicating whether there exists a subset V′ of cardinality at most l for some positive integer l, is known to be NP-complete even for planar graphs. In this paper, we establish that the MCS problem is NP-complete on trees. We also provide a fixed-parameter tractable (FPT) algorithm for MCS on trees parameterized by the number of colors (c) running in O(26cn6) time, significantly improving the currently best-known algorithm whose running time is O(24cn2c+3). In an effort to comprehensively understand the computational complexity of the MCS problem across different graph classes, we extend our investigation to interval graphs. We show that it remains NP-complete for interval graphs, thus enriching graph classes where MCS remains intractable. © 2024 Aritra Banik, Sayani Das, Anil Maheshwari, Bubai Manna, Subhas C. Nandy, Krishna Priya K. M., Bodhayan Roy, Sasanka Roy, and Abhishek Sahu.

关键词： Undirected graphs

来源：评论

学校读者我要写书评

暂无评论

Anomaly Detection in Evolutionary Social Networks leveraging Community Structure 15

Anomaly Detection in Evolutionary Social Networks leveraging...

引用

15th IEEE International Conference on Service Operations and Logistics, and Informatics, SOLI 2021

作者： Ghoshal, Arnab Kumar Das, Nabanita Asutosh College Department of Computer Science Kolkata India Advanced Computing and Microelectronics Unit Indian Statistical Institute Kolkata India

ISBN: (纸本)9781665467223

Social networks are temporally evolving by nature and in general, the evolution takes place gradually with time. But occasionally, the nodes may exhibit anomalous behavior that is to be detected and reported in real time. Usually, the social networks are represented as a temporal stream of weighted graphs, where edge weights stand for frequency or power of actions. Here, for identification of anomalies in evolutionary social networks, we follow an action based approach leveraging the community structure of the network, where it is shown that only the Community Boundary Nodes are enough to detect anomaly in a temporally evolving social network. We introduce a new definition of anomaly score for nodes based on its action history. To the best of our knowledge, this is the first work to exploit the community boundary nodes of an evolutionary social network to identify the graph snapshots containing anomalous events. Experimental studies on real-world as well as synthetic evolutionary networks show that the proposed technique achieves almost 13% improvement in F-Score compared to the state-of-the-art algorithms. Moreover, parallel implementation of the proposed technique results nearly 6 x speedup making it suitable for real time computation of anomaly in evolutionary social networks. © 2021 IEEE.

关键词： Anomaly detection

来源：评论

学校读者我要写书评

暂无评论

Proving a Conjecture on 8-Distance Coloring of the Infinite Hexagonal Grid? 22

Proving a Conjecture on 8-Distance Coloring of the Infinite ...

引用

22nd Italian Conference on Theoretical Computer Science, ICTCS 2021

作者： Ghosh, Sasthi C. Koley, Subhasis Advanced Computing And Microelectronics Unit Indian Statistical Institute 203 B. T. Road Kolkata700108 India

Given p ∈ N, a p distance coloring is a coloring f : V → {1, 2, · · · , n} of the vertices of G such that f(u) 6= f(v) for all pair of vertices u and v in G where d(u, v), the distance between u and v, is at most p. Here d(u, v) is defined as the minimum number of edges required to connect u and v in G. The p distance chromatic number λ p (G) of a graph G is the minimum n such that G admits a p distance coloring of G. Such type of distance coloring is relevant when frequency assignment problem is formulated as a graph coloring problem. In the context of frequency assignment problem, sometimes cellular network can be modelled as an infinite hexagonal grid TH. Therefore λ p (TH) has practical relevance. For even p ≥ 8, it was conjectured by Jacko and Jendrol [Discussiones Mathematicae Graph Theory, 2005] that λ p (TH) = " 3 8 p + 4 3 2 # where [x] is an integer, x ∈ R and x - 1 2 © 2021 CEUR-WS. All rights reserved.

关键词： Coloring

来源：评论

学校读者我要写书评

暂无评论

Performance evaluation of conditional handover in 5G systems under fading scenario

arXiv

引用

arXiv 2024年

作者： Deb, Souvik Rathod, Megh Balamurugan, Rishi Ghosh, Shankar K. Singh, Rajeev K. Sanyal, Samriddha Department of Computer Science and Engineering Shiv Nadar Institution of Eminence Delhi NCR India Advanced Computing and Microelectronics Unit Indian Statistical Institute Kolkata India School of Computing and Data Science FLAME University Pune India

To enhance the handover performance in fifth generation (5G) cellular systems, conditional handover (CHO) has been evolved as a promising solution. Unlike A3 based handover where handover execution is certain after receiving handover command from the serving access network, in CHO, handover execution is conditional on the RSRP measurements from both current and target access networks, as well as on mobility parameters such as preparation and execution offsets. Analytic evaluation of conditional handover performance is unprecedented in literature. In this work, handover performance of CHO has been carried out in terms of handover latency, handover packet loss and handover failure probability. A Markov model accounting the effect of different mobility parameters (e.g., execution offset, preparation offset, time-to-preparation and time-to-execution), UE velocity and channel fading characteristics;has been proposed to characterize handover failure. Results obtained from the analytic model has been validated against extensive simulation results. Our study reveal that optimal configuration of Oexec, Oprep, Texec and Tprep is actually conditional on underlying UE velocity and fading characteristics. This study will be helpful for the mobile operators to choose appropriate thresholds of the mobility parameters under different channel condition and UE velocities. Copyright © 2024, The Authors. All rights reserved.

关键词： Packet loss

来源：评论

学校读者我要写书评

暂无评论

FAST 3D VOLUMETRIC IMAGE RECONSTRUCTION FROM 2D MRI SLICES BY PARALLEL PROCESSING

arXiv

引用

arXiv 2023年

作者： Ghoshal, Somoballi Goswami, Shremoyee Chakrabarti, Amlan Sur-Kolay, Susmita A. K. Choudhury School of Information Technology University of Calcutta India Advanced Computing and Microelectronics Unit Indian Statistical Institute India

Magnetic Resonance Imaging (MRI) is a technology for non-invasive imaging of anatomical features in detail. It can help in functional analysis of organs of a specimen but it is very costly. In this work, methods for (i) virtual three-dimensional (3D) reconstruction from a single sequence of two-dimensional (2D) slices of MR images of a human spine and brain along a single axis, and (ii) generation of missing inter-slice data are proposed. Our approach helps in preserving the edges, shape, size, as well as the internal tissue structures of the object being captured. The sequence of original 2D slices along a single axis is divided into smaller equal sub-parts which are then reconstructed using edge preserved kriging interpolation to predict the missing slice information. In order to speed up the process of interpolation, we have used multiprocessing by carrying out the initial interpolation on parallel cores. From the 3D matrix thus formed, shearlet transform is applied to estimate the edges considering the 2D blocks along the Z axis, and to minimize the blurring effect using a proposed mean-median logic. Finally, for visualization, the sub-matrices are merged into a final 3D matrix. Next, the newly formed 3D matrix is split up into voxels and marching cubes method is applied to get the approximate 3D image for viewing. To the best of our knowledge it is a first of its kind approach based on kriging interpolation and multiprocessing for 3D reconstruction from 2D slices, and approximately 98.89% accuracy is achieved with respect to similarity metrics for image comparison. The time required for reconstruction has also been reduced by approximately 70% with multiprocessing even for a large input data set compared to that with single core processing. © 2023, CC BY.

关键词： Magnetic resonance imaging

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：