A REVIEW ON UNDERWATER ACOUSTIC/OPTICAL MODEMS: DESIGN ISSUES, RECENT DEVELOPMENTS AND CHALLENGES IN UNDERWATER COMMUNICATION

2020 ◽  
Vol 9 (2) ◽  
pp. 21
Author(s):  
CH. PALLAVI ◽  
G. SREENIVASULU ◽  
◽  
Keyword(s):  
Underwater Communication ◽  
Design Issues ◽  
Underwater Acoustic ◽  
Recent Developments

Compatibility-Based Design for Contact Stress

1990 ◽  
Author(s):  
K. Ishii ◽  
J. M. Klinger ◽  
B. J. Hamrock
Keyword(s):  
Contact Stress ◽  
Elastohydrodynamic Lubrication ◽  
Contact Stresses ◽  
Efficient Computation ◽  
Design Issues ◽  
Knowledge Based ◽  
Compatibility Analysis ◽  
Recent Developments ◽  
Machine Elements ◽  
Quantitative Performance

Abstract This paper discusses the combined use of quantitative analysis equations and knowledge-based techniques in the design of machine elements. We introduce the method of design compatibility analysis to 1) guide the application of correct analysis equations, 2) interpret the results of analysis, and 3) suggest modifications to improve the design. As an example vehicle, this paper focuses on design issues related to contact stresses and lubrication between two surfaces. The compatibility approach covers not only quantitative performance measures, but also the qualitative design issues such as suitability of surface materials, machining methods, surface roughness, lubricants, etc. To verify the utility of this concept, we developed DECS (Design Expert for Contact Stress), a PC-based design-aid for contact stresses and lubrication. DECS uses Prolog for top-level management and inference, while C provides and efficient computation of the quantitative equations. DECS also utilizes some recent developments in the computations of contact stress and elastohydrodynamic lubrication. Our method would be useful in many other design applications.

Compatibility-Based Design for Contact Stress

1993 ◽  
Vol 115 (3) ◽  
pp. 359-366 ◽  
Author(s):  
K. Ishii ◽  
J. M. Klinger ◽  
B. J. Hamrock
Keyword(s):  
Contact Stress ◽  
Elastohydrodynamic Lubrication ◽  
Contact Stresses ◽  
Efficient Computation ◽  
Design Issues ◽  
Knowledge Based ◽  
Compatibility Analysis ◽  
Recent Developments ◽  
Machine Elements ◽  
Quantitative Performance

This paper discusses the combined use of quantitative analysis equations and knowledge-based techniques in the design of machine elements. We introduce the method of design compatibility analysis to (1) guide the application of correct analysis equations, (2) interpret the results of analysis, and (3) suggest modifications to improve the design. As an example vehicle, this paper focuses on design issues related to contact stresses and lubrication between two surfaces. The compatibility approach covers not only quantitative performance measures, but also the qualitative design issues such as suitability of surface materials, machining methods, surface roughness, lubricants, etc. To verify the utility of this concept, we developed DECS (Design Expert for Contact Stress), a PC-based design-aid for contact stresses and lubrication. DECS uses Prolog for top-level management and inference, while C provides the efficient computation of the quantitative equations. DECS also utilizes some recent developments in the computations of contact stress and elastohydrodynamic lubrication. Our method would be useful in many other design applications.

Protocol design issues in underwater acoustic networks

2011 ◽  
Vol 34 (17) ◽  
pp. 2013-2025 ◽  
Author(s):  
Paolo Casari ◽  
Michele Zorzi
Keyword(s):  
Protocol Design ◽  
Design Issues ◽  
Underwater Acoustic ◽  
Acoustic Networks ◽  
Underwater Acoustic Networks

scholarly journals Acoustic Parametric Signal Generation for Underwater Communication

2018 ◽  
Author(s):  
María Campo-Valera ◽  
Miguel Ardid ◽  
Dídac D. Tortosa ◽  
Ivan Felis ◽  
Juan A. Martínez-Mora ◽  
...  
Keyword(s):  
Resonance Frequency ◽  
Carrier Frequency ◽  
Signal Generation ◽  
Binary Codes ◽  
Underwater Communication ◽  
Underwater Acoustic Communications ◽  
Bit Rate ◽  
Acoustic Communications ◽  
Underwater Acoustic ◽  
Different Types

This paper presents a study of different types of parametric signals with application to underwater acoustic communications. In all the signals, the carrier frequency is 200 kHz, which corresponds to the resonance frequency of the transducer under study and different modulations are presented and compared. In this sense, we study modulations with parametric sine sweeps (4 to 40 kHz) that represent binary codes (zeros and ones), getting closer to the application in acoustic communications. The different properties of the transmitting signals in terms of bit rate, directivity, efficiency and power needed are discussed as well.

scholarly journals Contemporary Business Analytics: An Overview

Data ◽  
2021 ◽  
Vol 6 (8) ◽  
pp. 86
Author(s):  
Wullianallur Raghupathi ◽  
Viju Raghupathi
Keyword(s):  
Life Cycle ◽  
State Of The Art ◽  
The State ◽  
Business Analytics ◽  
Design Issues ◽  
Informed Decisions ◽  
Recent Developments ◽  
Architectural Framework

We examine the state-of-the-art of the business analytics field by identifying and describing the four types of analytics and the three pillars of modeling. Further, we offer a framework of the interplay between the types of analytics and those pillars of modeling. The article describes the architectural framework and outlines an analytics methodology life cycle. Additionally, key contemporary design issues and challenges are highlighted. In this paper, we offer researchers and practitioners a contemporary overview of business analytics. As business analytics has emerged as a distinct discipline with the key objective to gain insight to make informed decisions, this state-of-the art survey sheds light on recent developments in the business analytics discipline.

scholarly journals Simulation model for energy consumption and acoustic underwater communication of autonomous underwater vehicles

2021 ◽  
Author(s):  
Peter Danielis ◽  
Helge Parzyjegla ◽  
Mostafa Assem Mohamed Ali ◽  
Frank Sill Torres
Keyword(s):  
Energy Consumption ◽  
Simulation Model ◽  
Acoustic Communication ◽  
Acoustic Waves ◽  
Autonomous Underwater Vehicles ◽  
Underwater Vehicles ◽  
Underwater Acoustic Communication ◽  
Network Simulator ◽  
Underwater Communication ◽  
Underwater Acoustic

AbstractRecently, cooperative autonomous underwater vehicles (AUVs) have been deployed in application areas such as surveillance and protection of maritime infrastructures for inspection and monitoring purposes. These cooperative methodologies require wireless transmission of data between the different AUVs operating in the underwater environment. Communication over ranges exceeding 100 m exclusively relies on underwater acoustic communication. However, the propagating acoustic waves suffer from several challenges due to the presence of path loss, multi-path propagation, the slow and variant propagation speed, background noise, and Doppler distortion. Since the power supply of the AUVs is limited, communication must be very energy efficient and energy constraints have to be known to be able to plan the mission of AUVs. Due to the difficulties of real experiments, the modeling and simulation of the energy consumption and underwater acoustic communication play an essential role in studying and developing these systems. We provide a modular simulation model for the energy consumption and acoustic underwater communication of AUVs implemented in the network simulator OMNeT++ using the INET framework. More specifically, we extend several INET modules in such a way as to reflect the characteristics of AUVs and underwater communication. We study and analyze the AUVs’ energy consumption and dependence of the message quality on different properties such as those mentioned above.

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