Theoretical Foundations of Communication of Numbers in Limited Time

, Ph.D. Dissertation Sharif University of Technology Ahmadipour, Niloufar (Author) ; Aminzadeh Gohari, Amin (Supervisor)

Abstract

Usually, in information theory, the length of the message (number of bits of information) is proportional to the number of channel uses, for example, in traditional channel coding, the number of messages is $ 2 ^{NR} $ and $ NR $ bits with $ N $ channel uses were sent. In fact, as the channel uses increase, the message bits increase linearly. But in this dissertation, the length of the message, or indeed the number of source observations, is a function of the number of channel uses.In this dissertation, we first study the problem of designing the best code for a discrete Poisson channel with memory (under peak-power and total-power constraints). The outputs of a discrete Poisson channel with...

Microstructural evaluation and mechanical properties of Al1050/TiO 2 -Graphite hybrid nanocomposite produced Via friction stir processing

, Article Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science ; Volume 50, Issue 5 , 2019 , Pages 2443-2461 ; 10735623 (ISSN) Farshbaf Ahmadipour, M ; Movahedi, M ; Kokabi, A. H ; Sharif University of Technology

Springer Boston 2019

Abstract

Production of Al1050/TiO 2 -graphite hybrid nanocomposite via friction stir processing (FSP) was studied. The effect of graphite-to-TiO 2 volume fraction ratio (Gr/TiO 2 ), at a constant rotational speed (ω) and three levels of tool traverse speed (ν), on the microstructural evolution and mechanical properties of the nanocomposites was investigated. While TiO 2 is supposed to enhance the strength and hardness, graphite is believed to improve the tribological behavior. Furthermore, formation of intermetallic compounds (IMCs) through the solid-state reactions between the reinforcements and aluminum matrix may also promote the mechanical properties. To assess these assumptions, longitudinal and...

State masking over a two-state compound channel

, Article IEEE Transactions on Information Theory ; Volume 67, Issue 9 , 2021 , Pages 5651-5673 ; 00189448 (ISSN) Salehkalaibar, S ; Yassaee, M. H ; Tan, V. Y. F ; Ahmadipour, M ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2021

Abstract

We consider the fundamental limits of reliable communication over a two-state compound channel when the state of the channel needs to be masked. Our model is closely related to an area of study known as covert communication, a setting in which the transmitter wishes to communicate to legitimate receiver(s) while ensuring that the communication is not detected by an adversary. Our main contribution is the establishment of upper and lower bounds on the throughput-key length region when the constraint that quantifies how much the states are masked is defined to be the total variation distance between the channel output distributions of the two states. When length of the key is sufficiently...

Electrodeposited Ni-Co alloy-particle composite coatings: A comprehensive review

, Article Surface and Coatings Technology ; Volume 382 , 2020 Safavi, M. S ; Tanhaei, M ; Ahmadipour, M. F ; Ghaffari Adli, R ; Mahdavi, S ; Walsh, F. C ; Sharif University of Technology

Elsevier B.V 2020

Abstract

Electrodeposited composite and nanocomposite layers have attracted considerable attention as engineering coatings, due to their favourable tribological properties and corrosion resistance. Ni[sbnd]Co alloy matrix composite coatings are particularly significant due to their extensive and developing industrial applications. Ceramic nanoparticles are commonly incorporated into the Ni[sbnd]Co alloy matrix to further improve their properties, opening new windows for industrial applications. This review aims to comprehensively assess the influence of operating parameters (including the type of current control, plating bath conditions, particle loading and size) on the deposit properties....

Magnetic nitrogen-rich UiO-66 metal-organic framework: an efficient adsorbent for water treatment

, Article ACS Applied Materials and Interfaces ; Volume 15, Issue 25 , 2023 , Pages 30106-30116 ; 19448244 (ISSN) Ahmadijokani, F ; Ahmadipouya, S ; Haris, M. H ; Rezakazemi, M ; Bokhari, A ; Molavi, H ; Ahmadipour, M ; Pung, S. Y ; Klemeš, J. J ; Aminabhavi, T. M ; Arjmand, M ; Sharif University of Technology

American Chemical Society 2023

Abstract

The postsynthetic modification of metal-organic frameworks (MOFs) has opened up a promising area to widen their water treatment application. However, their polycrystalline powdery state still restricts their widespread industrial-scale applications. Herein, the magnetization of UiO-66-NH2 is reported as a promising approach to facilitate the separation of the used MOFs after water treatment. A two-step postmodification procedure employing 2,4,6-trichloro-1,3,5-triazine (TCT) and 5-phenyl-1H-tetrazole (PTZ) agents was introduced to level up the adsorption performance of the magnetic nanocomposite. Despite a decrement in porosity and specific surface area of the designed MOFs (m-UiO-66-TCT)...

Physicomechanical Properties of Porous Materials by Spark Plasma Sintering

, Article Critical Reviews in Solid State and Materials Sciences ; Volume 45, Issue 1 , 2020 , Pages 22-65 Azarniya, A ; Azarniya, A ; Safavi, M. S ; Farshbaf Ahmadipour, M ; Esmaeeli Seraji, M ; Sovizi, S ; Saqaei, M ; Yamanoglu, R ; Soltaninejad, M ; Madaah Hosseini, H. R ; Ramakrishna, S ; Kawasaki, A ; Adams, S ; Reddy, M. V ; Sharif University of Technology

Taylor and Francis Inc 2020

Abstract

Metallic or ceramic micro/nanoporous materials have attracted particular attention due to some interesting structural and functional properties. There exist a variety of methods for producing porous materials by which optimized features can be reached. Spark plasma sintering (SPS) is one of these new-emerging approaches. This technique is often combined with conventional technologies and produce a variety of porous structures with tailorable microstructure and physicomechanical properties. This review addresses SPS and obtainable porous materials with nanoscale and microscale microstructural features. The processing methods, microstructural phenomena, and physicomechanical properties of...