scholarly journals Flow complexity in open systems: interlacing complexity index based on mutual information

2017 ◽  
Vol 825 ◽  
pp. 704-742 ◽  
Author(s):  
Jose M. Pozo ◽  
Arjan J. Geers ◽  
Maria-Cruz Villa-Uriol ◽  
Alejandro F. Frangi
Keyword(s):  
Mutual Information ◽  
Communication Systems ◽  
Communication Channel ◽  
Communication Theory ◽  
Open Systems ◽  
Straight Tube ◽  
Natural Distribution ◽  
Ergodic Processes ◽  
Complexity Index ◽  
Crucial Component

Flow complexity is related to a number of phenomena in science and engineering and has been approached from the perspective of chaotic dynamical systems, ergodic processes or mixing of fluids, just to name a few. To the best of our knowledge, all existing methods to quantify flow complexity are only valid for infinite time evolution, for closed systems or for mixing of two substances. We introduce an index of flow complexity coined interlacing complexity index (ICI), valid for a single-phase flow in an open system with inlet and outlet regions, involving finite times. ICI is based on Shannon’s mutual information (MI), and inspired by an analogy between inlet–outlet open flow systems and communication systems in communication theory. The roles of transmitter, receiver and communication channel are played, respectively, by the inlet, the outlet and the flow transport between them. A perfectly laminar flow in a straight tube can be compared to an ideal communication channel where the transmitted and received messages are identical and hence the MI between input and output is maximal. For more complex flows, generated by more intricate conditions or geometries, the ability to discriminate the outlet position by knowing the inlet position is decreased, reducing the corresponding MI. The behaviour of the ICI has been tested with numerical experiments on diverse flows cases. The results indicate that the ICI provides a sensitive complexity measure with intuitive interpretation in a diversity of conditions and in agreement with other observations, such as Dean vortices and subjective visual assessments. As a crucial component of the ICI formulation, we also introduce the natural distribution of streamlines and the natural distribution of world-lines, with invariance properties with respect to the cross-section used to parameterize them, valid for any type of mass-preserving flow.

scholarly journals Directed Data-Processing Inequalities for Systems with Feedback

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 533
Author(s):  
Milan S. Derpich ◽  
Jan Østergaard
Keyword(s):  
Mutual Information ◽  
Data Processing ◽  
Channel Coding ◽  
Communication Channel ◽  
Closed Loop ◽  
Transmission Rate ◽  
Information Rate ◽  
Random Input ◽  
Directed Information ◽  
Stochastic Mapping

We present novel data-processing inequalities relating the mutual information and the directed information in systems with feedback. The internal deterministic blocks within such systems are restricted only to be causal mappings, but are allowed to be non-linear and time varying, and randomized by their own external random input, can yield any stochastic mapping. These randomized blocks can for example represent source encoders, decoders, or even communication channels. Moreover, the involved signals can be arbitrarily distributed. Our first main result relates mutual and directed information and can be interpreted as a law of conservation of information flow. Our second main result is a pair of data-processing inequalities (one the conditional version of the other) between nested pairs of random sequences entirely within the closed loop. Our third main result introduces and characterizes the notion of in-the-loop (ITL) transmission rate for channel coding scenarios in which the messages are internal to the loop. Interestingly, in this case the conventional notions of transmission rate associated with the entropy of the messages and of channel capacity based on maximizing the mutual information between the messages and the output turn out to be inadequate. Instead, as we show, the ITL transmission rate is the unique notion of rate for which a channel code attains zero error probability if and only if such an ITL rate does not exceed the corresponding directed information rate from messages to decoded messages. We apply our data-processing inequalities to show that the supremum of achievable (in the usual channel coding sense) ITL transmission rates is upper bounded by the supremum of the directed information rate across the communication channel. Moreover, we present an example in which this upper bound is attained. Finally, we further illustrate the applicability of our results by discussing how they make possible the generalization of two fundamental inequalities known in networked control literature.

scholarly journals Laser technologies of data transfer in aquatic environment in the organization of underwater wireless communication networks

2021 ◽  
pp. 80-85
Author(s):  
В.Л. Мартынов ◽  
В.И. Дорошенко ◽  
Н.М. Божук ◽  
Ю.Г. Ксенофонтов
Keyword(s):  
Communication Networks ◽  
Optical Communication ◽  
Aquatic Environment ◽  
Communication Systems ◽  
High Speed ◽  
Data Transfer ◽  
Open Systems ◽  
Transmission Rate ◽  
Video Data ◽  
Optical Communication Systems

Решению вопросов, связанных с телекоммуникационным оборудованием, функционирующем в водной среде, в настоящее время уделяется особое внимание. На смену традиционным подводным системам обмена информацией в гидроакустических полях приходят открытые системы её оптической передачи и приёма, базирующиеся на лазерных технологиях. Это вызвано необходимостью трансляции с высокой разрешающей способностью видеоданных, среди которых, например, может быть либо визуальное отображение подводных систем в динамике, либо результаты мониторинга объектов подводной инфраструктуры в реальном масштабе времени, либо что-то другое с учётом требований Заказчика. Канал передачи такого большого объёма информации при условии ее считывания с задаваемым качеством должен иметь пропускную способность более 1 Мбит/с. Такую высокую скорость передачи невозможно реализовать в подводных гидроакустических системах, граница технических возможностей которых на превышает 10...50 кбит/с. В аналогичной ситуации при заданных параметрах канала связи частоты несущих оптического диапазона имеют порядок 1014 Гц, что обеспечивает динамический диапазон полосы пропускания в районе 1012…1013 Гц. С учётом условия квазимонохроматичности применение гидроакустических средств для передачи видеоданных становится проблематичным, так как техническая реализация такой задачи потребует слишком большого времени. С учётом сказанного, преимуществом подводных беспроводных оптических систем связи является их высокая широкополосность, которая обеспечит высокую скорость передачи данных. В статье обосновывается целесообразность использования открытых оптических системы связи для создания высокоскоростных подводных инфотелекоммуникаций, среди которых наиболее предпочтительными являются лазерные системы. Special attention is currently paid to the solution of issues related to telecommunication equipment operating in the aquatic environment. The traditional underwater systems for the exchange of information in hydroacoustic fields are being replaced by open systems for its optical transmission and reception, based on laser technologies.This is due to the need to broadcast high-resolution video data, among which, for example, there can be either a visual display of underwater systems in dynamics, or the results of monitoring objects of underwater infrastructure in real time, or something else, taking into account the requirements of the Customer. The transmission channel of such a large amount of information, provided it is read with a specified quality, must have a bandwidth of more than 1 Mbit / s. Such a high transmission rate cannot be realized in underwater sonar systems, the technical capabilities limit of which does not exceed 10 ... 50 kbit/s. In a similar situation, given the parameters of the communication channel, the carrier frequencies of the optical range are 1014 Hz, which provides a dynamic bandwidth range about 1012…1013Hz. Taking into account the condition of quasimonochromaticity, the use of hydroacoustic means for transmitting video data becomes problematic, since the technical implementation of such a task will take too long. In view of the above, the advantage of underwater wireless optical communication systems is their high broadband, which will provide a high data transfer rate. The article substantiates the expediency of using open optical communication systems for creating high-speed underwater information telecommunications, among which the most preferable are laser systems.

scholarly journals Effect of the defected microstrip structure shapes on the performance of dual-band bandpass filter for wireless communications

2021 ◽  
Vol 10 (1) ◽  
pp. 232-240
Author(s):  
Mussa Mabrok ◽  
Zahriladha Zakaria ◽  
Yully Erwanti Masrukin ◽  
Tole Sutikno ◽  
Hussein Alsariera
Keyword(s):  
Wireless Communication ◽  
Communication Systems ◽  
Bandpass Filter ◽  
Dual Band ◽  
Center Frequency ◽  
Wireless Communication Systems ◽  
Notch Band ◽  
Quarter Wavelength ◽  
Crucial Component ◽  
Microstrip Structure

Due to the progression growth of multiservice wireless communication systems in a single device, multiband bandpass filter has attract a great attention to the end user. Therefore, multiband bandpass filter is a crucial component in the multiband transceivers systems which can support multiple services in one device. This paper presents a design of dual-band bandpass filter at 2.4 GHz and 3.5 GHz for WLAN and WiMAX applications. Firstly, the wideband bandpass filter is designed at a center frequency of 3 GHz based on quarter-wavelength short circuited stub. Three types of defected microstrip structure (DMS) are implemented to produce a wide notch band, which are T-inversed shape, C-shape, and U- Shape. Based on the performance comparisons, U-shaped DMS is selected to be integrated with the bandpass filter. The designed filter achieved two passbands centered at 2.51 GHz and 3.59 GHz with 3 dB bandwidth of 15.94 % and 15.86 %. The proposed design is very useful for wireless communication systems and its applications such as WLAN and WiMAX 

scholarly journals Research of the Channel Estimation in Wireless Communication Systems

2019 ◽  
Vol 25 ◽  
pp. 01002 ◽  
Author(s):  
Lili Zhao ◽  
Peng Zhang ◽  
Qicai Dong ◽  
Xiangyang Huang ◽  
Jianhua Zhao ◽  
...  
Keyword(s):  
Wireless Communication ◽  
Channel Estimation ◽  
Communication Technology ◽  
Communication Systems ◽  
Communication Channel ◽  
Data Transfer ◽  
Estimation Methods ◽  
Wireless Communication Systems ◽  
Data Transfer Rate

Wireless communication technology has been developed rapidly after entering the 21st century. Data transfer rate increased significantly as well as the bandwidth became wider and wider from 2G to 4G in wireless communication systems. Channel estimation is an import part of any communication systems; its accuracy determines the quality of the whole communication. Channel estimation methods of typical wireless communication systems such as UWB, 2G and 3G have been researched.

scholarly journals Enhancing the Performance of Medical Implant Communication Systems through Cooperative Diversity

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Barnabás Hegyi ◽  
János Levendovszky
Keyword(s):  
Cooperative Communication ◽  
System Performance ◽  
Communication Systems ◽  
Communication Channel ◽  
Cooperative Diversity ◽  
Communication Link ◽  
Medical Implants ◽  
Medical Implant ◽  
Cardioverter Defibrillators ◽  
Implant Communication

Battery-operated medical implants—such as pacemakers or cardioverter-defibrillators—have already been widely used in practical telemedicine and telecare applications. However, no solution has yet been found to mitigate the effect of the fading that the in-body to off-body communication channel is subject to. In this paper, we reveal and assess the potential of cooperative diversity to combat fading—hence to improve system performance—in medical implant communication systems. In the particular cooperative communication scenario we consider, multiple cooperating receiver units are installed across the room accommodating the patient with a medical implant inside his/her body. Our investigations have shown that the application of cooperative diversity is a promising approach to enhance the performance of medical implant communication systems in various aspects such as implant lifetime and communication link reliability.

SIGNAL DROPOUT RECONSTRUCTION IN COMMUNICATION WITH CHAOS

1999 ◽  
Vol 09 (12) ◽  
pp. 2291-2293 ◽  
Author(s):  
INES P. MARIÑO ◽  
EPAMINONDAS ROSA ◽  
CELSO GREBOGI
Keyword(s):  
Communication Systems ◽  
Communication Channel ◽  
Recovery Method ◽  
Chaotic Signals ◽  
Signal Dropout

Recently, it has been demonstrated that chaotic signals can be used as carriers of information in communication systems. In this paper we propose a recovery method which, exploiting the determinism and redundancy of chaotic signals, allows us to reconstruct missing or distorted parts of a waveform that has been transmitted through a communication channel.

scholarly journals Complex methodology of parameters management of military radio networks in the conditions of uncertainty of the radioelectronic situation

2020 ◽  
pp. 73-85
Author(s):  
А.В. Шишацький ◽  
Ю.В. Журавський ◽  
В.М. Остапчук ◽  
М.В. Сова ◽  
О.Д. Гаращук ◽  
...  
Keyword(s):  
Communication Systems ◽  
Open Systems ◽  
Radio Networks ◽  
Open Architecture ◽  
Reference Network ◽  
Radio Communication ◽  
Network Resources ◽  
Radio Communications ◽  
Electronic Environment ◽  
Radio Systems

The experience of the Joint Forces operation (Anti-terrorist operation in Donetsk and Luhansk oblasts) shows that the current order of management of military radio communication systems does not always meet the modern requirements for them. The classic centralized approach to the management of channel and network resources of military radio systems does not quite meet modern requirements, so the authors of this article proposed to take mobile self-organizing networks as a basic principle of construction. The authors propose a comprehensive method of managing the parameters of military radio networks in conditions of uncertainty of the electronic environment, the essence of which is to ensure the maintenance of the specified values of the performance of military radio communication systems at the appropriate level. The article is based on the control principle, which is described in the reference network model of open systems interaction, but with some additions and changes. This approach generally allows for end-to-end management of channel and network resources of military radio systems in a complex electronic environment. In the article, the device of fuzzy logic, the theory of electronic suppression, neural networks, the theory of noise protection, the theory of antennas, noise-resistant coding are used. The proposed complex methodology should be used in the development of software for modules (units) for the assessment of advanced radio communications, based on open architecture interfaces version SCA 2.2, which will: use effective signal-code structures to ensure noise immunity of channels; to ensure efficient use of the radio frequency resource of programmable radio communication means; increase the speed of evaluation of communication channels; reduce the use of computing resources of radio communications with programmable architecture.

scholarly journals The Entropy Function for Non Polynomial Problems and Its Applications for Turing Machines

2020 ◽  
Author(s):  
Matheus Santana Lima
Keyword(s):  
Communication Systems ◽  
Decision Problem ◽  
Communication Channel ◽  
Solution Space ◽  
Search Space ◽  
Decision Problems ◽  
Turing Machines ◽  
Bernoulli Process ◽  
General Process ◽  
New Interpretation

We present a general process for the halting problem, valid regardless of the time and space computational complexity of the decision problem. It can be interpreted as the maximization of entropy for the utility function of a given Shannon-Kolmogorov-Bernoulli process. Applications to non-polynomials problems are given. The new interpretation of information rate proposed in this work is a method that models the solution space boundaries of any decision problem (and non polynomial problems in general) as a communication channel by means of Information Theory. We described a sort method that order objects using the intrinsic information content distribution for the elements of a constrained solution space - modeled as messages transmitted through any communication systems. The limits of the search space are defined by the Kolmogorov-Chaitin complexity of the sequences encoded as Shannon-Bernoulli strings. We conclude with a discussion about the implications for general decision problems in Turing machines.

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