information signal
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2022 ◽  
Vol 18 (2) ◽  
pp. 1-27
Author(s):  
Hang Cui ◽  
Tarek Abdelzaher

This article narrows the gap between physical sensing systems that measure physical signals and social sensing systems that measure information signals by (i) defining a novel algorithm for extracting information signals (building on results from text embedding) and (ii) showing that it increases the accuracy of truth discovery—the separation of true information from false/manipulated one. The work is applied in the context of separating true and false facts on social media, such as Twitter and Reddit, where users post predominantly short microblogs. The new algorithm decides how to aggregate the signal across words in the microblog for purposes of clustering the miscroblogs in the latent information signal space, where it is easier to separate true and false posts. Although previous literature extensively studied the problem of short text embedding/representation, this article improves previous work in three important respects: (1) Our work constitutes unsupervised truth discovery, requiring no labeled input or prior training. (2) We propose a new distance metric for efficient short text similarity estimation, we call Semantic Subset Matching , that improves our ability to meaningfully cluster microblog posts in the latent information signal space. (3) We introduce an iterative framework that jointly improves miscroblog clustering and truth discovery. The evaluation shows that the approach improves the accuracy of truth-discovery by 6.3%, 2.5%, and 3.8% (constituting a 38.9%, 14.2%, and 18.7% reduction in error, respectively) in three real Twitter data traces.


Author(s):  
Hayder Mazin Makki Alibraheemi ◽  
Qais Al-Gayem ◽  
Ehab AbdulRazzaq Hussein

<span>This paper presents the design and simulation of a hyperchaotic communication system based on four dimensions (4D) Lorenz generator. The synchronization technique that used between the master/transmitter and the slave/receiver is based on dynamic feedback modulation technique (DFM). The mismatch error between the master dynamics and slave dynamics are calculated continuously to maintain the sync process. The information signal (binary image) is masked (encrypted) by the hyperchaotic sample x of Lorenz generator. The design and simulation of the overall system are carried out using MATLAB Simulink software. The simulation results prove that the system is suitable for securing the plain-data, in particular the image data with a size of 128×128 pixels within 0.1 second required for encryption, and decryption in the presence of the channel noise. The decryption results for gray and colored images show that the system can accurately decipher the ciphered image, but with low level distortion in the image pixels due to the channel noise. These results make the proposed cryptosystem suitable for real time secure communications.</span>


2021 ◽  
Author(s):  
Unai Arregui Leon ◽  
Davide Rocco ◽  
Luca Carletti ◽  
Marco Peccianti ◽  
Stefano Maci ◽  
...  

Abstract The THz spectrum (spanning from 0.3 THz to 30 THz) offers the potential of a plethora of applications, ranging from the imaging through non transparent media to wireless-over-fiber communications and THz-photonics. The latter framework would greatly benefit from the development of optical-to-THz wavelength converters. Exploiting Difference Frequency Generation in a nonlinear all dielectric nanoantenna, we propose a compact solution to this problem. By means of a near-Infrared pump beam (at ω1), the information signal in the optical domain (at ω2) is converted to the THz band (at ω3 = ω2 − ω1). The approach is completely transparent with respect to the modulation format, and can be easily integrated in a metasurface platform for simultaneous frequency and spatial moulding of THz beams.


Author(s):  
I. V. Stepanyan

The author examines new challenges of ergonomics and occupational health, including unknown risks, issues of prevention, and ethics. The author also presents an overview of modern bioinformatics systems and visualization methods in bioinformatics. The researcher analyzed the health risks of human interaction with large volumes of textual information and advanced computational methods to prevent computer syndrome, including overstrain of the visual analyzer and pain in the back, neck, and hands. The study aims to analyze the representations of hereditary molecular genetic information in the form of graphic patterns available for visual perception, characterizing the initial data, and study the possibility of visualizing large amounts of data using the method of characteristic patterns. The author developed new methods of presenting large volumes of hereditary genetic information in bioinformatic systems. The basis of the method is information processing based on computer algorithms. The methods allow us to visually assess the differences in the genetic structure of various species of living organisms and identify the features of their nucleotide composition. The fixation of the internal ordering of the information signal in an individual graphical quasi-fractal structure is a characteristic feature of the methods considered. It makes it possible to expand the possibilities of visual-analytical thinking of a person when interacting with large amounts of information through bioinformatics tools.


2021 ◽  
Vol 2127 (1) ◽  
pp. 012068
Author(s):  
K A Vytovtov ◽  
E A Barabanova ◽  
V M Vishnevsky

Abstract In this paper the new 1×4 optical demultiplexer for next-generation all-optical switching systems is proposed. The controlled mirrors are the main elements of this device. The control voltage for this mirror is generated by a rectenna from an optical control signal. In according to operation principle this optical signal enters the system simultaneously with an information signal. The analytical approach of calculation energy losses in the demultiplexer based on the translation matrix method is proposed. And also the analytical method of performance calculation is offered for the first time. First of all, the delay time due the transient mode in the power supply circuit is found. The equivalent electrical scheme of the optical demultiplexer is proposed for the first time. Note that the theoretical results obtained in this work can be used for analysing various controlled optical devices. The numerical calculations in accordance to the presented methods are carried out also.


Author(s):  
Atik Charisma ◽  
Rizky Nur Akbar Setiawan ◽  
Een Taryana ◽  
Hajiar Yuliana ◽  
Alifa Rike Indriani

Kegiatan masyarakat di era sekarang yang serba digital menggunakan teknologi tanpa kabel (wireless). Teknologi tanpa kabel menjadi andalan komunikasi, namun seiring perkembangann zaman, ada sebuah teknologi tanpa kabel dengan memanfaatkan cahaya tampak.  Teknologi ini dikenal dengan istilah visible light communication (VLC). Sistem VLC terdiri dari bagian transmitter dan receiver. Transmitter berupa komponen-komponen elektronika yang terintegrasi dengan cahaya tampak sebagai media transmisi. Pada penelitian ini membuat bagian transmitter dan receiver untuk komunikasi audio. Cahaya tampak sebagai media transmisi menggunakan laser led karena cahaya dari laser led ini lebih fokus dan pancaran cahayanya lebih jauh dibandingkan dengan yang lain. Sedangkan di sisi receiver menggunakan solar panel sebagai penerima sinyal informasi yang dikirimkan. Penelitian ini berhasil membuat sebuah sistem komunikasi audio berbasis visible light communication. Variasi jarak antara transmitter dan receiver mempengaruhi kualitas suara yang diterima. Pada jarak 500 cm kualitas suara yaitu 99,2 dB pada kondisi gelap dan 99,1 dB kondisi terang. Perubahan sudut pancar transmitter terhadap receiver juga mempengaruhi hasil kualitas suara. Kualitas suara terbaik pada sudut 900 di kondisi terang dengan jarak 50 cm sebesar 97,9 dB sedangkan di kondisi gelap dengan jarak 50 cm  pada sudut 1000 sebesar 98,1 dB.   Abstract The people activities in today's digital era use wireless technology. Wireless technology has become the mainstay of communication, but along with the times, there is a wireless technology that uses visible light. This technology is known as visible light communication (VLC). The VLC system consist of transmitter and receiver. Transmitters are electronic components that are integrated with visible light as a transmission medium. In this study, the transmitter and receiver are made for audio communication. Visible light as a transmission medium uses an LED laser because the light from this LED laser is more focused and the light beam is farther away than the others. While on the receiver side using a solar panel as a receiver of the information signal that is sent. This research succeeded in making an audio communication system based on visible light communication. Variations in the distance between the transmitter and receiver affect the quality of the received sound. At a distance of 500 cm in dark conditions, the sound quality is 99.2 dB in light conditions and 99.1 dB. Changes in the beam angle of tranmitter to receiver also affect the sound quality. The best sound quality at an angle of 900 in bright conditions with a distance of 50 cm is 97.9 dB while in dark conditions with a distance of 50 cm at an angle of 1000 is 98.1 dB.


Author(s):  
С.С. Печников ◽  
С.А. Шерстюков

Рассмотрен процесс формирования радиосигнала с помощью квадратурного модулятора. Точность осуществления переноса на несущую является критически важным фактором. При передаче информационного сообщения значения сигнала несущей частоты должны принимать соответствующие дискретные значения, согласно закону изменения информационной последовательности, таким образом, формирование неискажённого радиосигнала является одним из основных требований, предъявляемых к работе квадратурного модулятора. При реализации сигналов с угловой модуляцией, как правило, используют генератор, управляемый напряжением. Проанализирована работа квадратурного модулятора и квадратурного фазового модулятора, основанного на формирователях функциональных составляющих модулирующего сигнала. Предложен метод компенсации искажений, возникающих в балансных смесителях и фазовращателе за счет быстроизменяющихся помех, приходящих с выхода высокочастотного генератора или с выхода усилителя мощности по цепи обратной связи, а также медленных отклонений фазы и амплитуды сигнала. Проведено моделирование работы схемы, осуществляющей компенсацию амплитудно-фазовых искажений квадратурного модулятора сигналов угловой модуляции за счёт генерирования компенсационных сигналов. Предложена структурная схема синтеза неискаженного сигнала амплитудно-фазовой модуляции с компенсацией амплитудно-фазовой нестабильности квадратурного формирователя, позволяющая осуществлять нелинейное усиление радиосигнала The paper considers the process of data transmission over a radio channel by modulating the parameters of the carrier wave with an information signal. When transmitting an information signal, the carrier frequency values must take discrete values in one-to-one correspondence with the information sequence, thus the formation of an undistorted radio signal is one of the main requirements for the operation of a quadrature modulator. The article analyzes the operation of a quadrature modulator and a quadrature phase modulator based on the shapers of the functional components of the modulating signal. We propose a distortion compensation method using synthesized compensation signals, which makes it possible to effectively compensate, firstly, rapidly changing noise inside balanced modulators and phase shifters, and secondly, noise coming along with an input high-frequency signal, for example, from the output of a power amplifier through circuits feedback and, third, slow deviations of amplitudes and phases. We carried out the modeling of the distortion compensation method using synthesized compensation signals


2021 ◽  
Vol 6 (3(36)) ◽  
pp. 13-17
Author(s):  
Yuriy Borisovich Nechaev ◽  
Ilya Vladimirovich Peshkov ◽  
Natalia Alexandrovna Fortunova ◽  
Irina Nikolaevna Zaitseva

The article describes a simulation model of a digital antenna array, which can be used in broadband signal transmission systems under the influence of broadband interference. The initial information signal has a speed of 19200 bit / s for the I and Q stream. It is proved that the signal level after applying the diagramming of a digital antenna array is four times higher than the signal level without its use, which confirms the advantage of digital radio systems.


2021 ◽  
pp. 60-65
Author(s):  
Nikolay Pshchelko ◽  
Olga Tsareva

The existing methods of geodetic monitoring of deformations and deviations caused by them are considered. It is shown that due to the instability of the position of the load suspended on a thread in a sufficiently strong electric field, it is possible to measure the direction of deviation of the observed object even when the deviation tends to zero. A quantitative model is considered for calculating the values of the electrical voltages used to ensure the failure-free operation of the device. The main structural elements of the device and a method for recording an information signal are proposed. It is concluded that there are prerequisites for the widespread implementation into practice of devices for determining the direction of small deviations based on the use of an electric field.


Author(s):  
Emin T Sunny

Development affirmation is considered as a huge endeavor in various applications, particularly in clinical consideration organizations. Among these applications consolidate clinical decisive, seeing of customers' consistently timetable and ID of unusual cases. Here we present an approach for the development affirmation using an accelerometer sensor embedded in a mobile phone. This strategy uses a transparently available accelerometer dataset as the unrefined information signal. The features of the sign are picked subject to the time and repeat space. By then, Principal Component Analysis (PCA) is used to diminish the dimensionality of the features and concentrate the primary ones that can describe human activities. An assessment collaboration is performed between the primary unrefined data and PCA-based features and moreover, time and repeat region features are similarly contemplated using a couple of AI classifiers. The got results show that the PCA-based features get higher affirmation rate while repeat region features have higher exactness, with the speed of 96.11% and 92.10% independently.


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