scholarly journals Localisation of Unmanned Underwater Vehicles (UUVs) in Complex and Confined Environments: A Review

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6203
Author(s):  
Simon Watson ◽  
Daniel A. Duecker ◽  
Keir Groves
Keyword(s):  
State Of The Art ◽  
Underwater Vehicles ◽  
Future Research ◽  
Aquatic Environments ◽  
Storage Tanks ◽  
Unmanned Underwater Vehicles ◽  
Liquid Storage ◽  
Low Illumination ◽  
Bodies Of Water ◽  
Remote Inspection

The inspection of aquatic environments is a challenging activity, which is made more difficult if the environment is complex or confined, such as those that are found in nuclear storage facilities and accident sites, marinas and boatyards, liquid storage tanks, or flooded tunnels and sewers. Human inspections of these environments are often dangerous or infeasible, so remote inspection using unmanned underwater vehicles (UUVs) is used. Due to access restrictions and environmental limitations, such as low illumination levels, turbidity, and a lack of salient features, traditional localisation systems that have been developed for use in large bodies of water cannot be used. This means that UUV capabilities are severely restricted to manually controlled low-quality visual inspections, generating non-geospatially located data. The localisation of UUVs in these environments would enable the autonomous behaviour and the development of accurate maps. This article presents a review of the state-of-the-art in localisation technologies for these environments and identifies areas of future research to overcome the challenges posed.

SEISMIC RESISTANT DESIGN OF CYLINDRICAL LIQUID STORAGE TANKS

1981 ◽  
pp. 77
Author(s):  
Vitelmo Bertero
Keyword(s):  
Seismic Behavior ◽  
State Of The Art ◽  
The State ◽  
Experimental Investigations ◽  
Future Research ◽  
Storage Tanks ◽  
Liquid Storage ◽  
Different Types ◽  
Seismic Resistant ◽  
Recent Earthquakes

This is a paper that summarizes the state of the practice and state of the art in the prediction of seismic behavior of cylindrical liquid storage tanks. It can be divided into five parts. In the first part the seismic performance of these types of tanks during recent   earthquakes is brielfly reviewed. From this review it becomes evident that a large percentage of these tanks have failed or suffered severe damages. The different types of failure are classified into several categories. The second part of the paper discusses the desing of some of the thank that suffered damages andthe state of the practice is summarized by reviewing present seismic code desing provisions. Thirdly, the soundness of these code provisions is analyzed in view of the state of thank.  Results obtained in recent theoretical and experimental investigations of such behavior are summarized and implications regarding needed improvement in seismic desing are assessed. Results from analyses of an existing  thank using different methods are presented and compared. An improved procedure for the practical seismic resistant desing of these thanks is outlined in the fourth part of the paper. A series of practical desing rules which provide extra margins of safety are offered and the extra cost required is discussed. Finally, recommendations for future research to improve the desing and construction of this type of liquid storage thanks are formuated.

scholarly journals Control of DC Motors to Guide Unmanned Underwater Vehicles

2021 ◽  
Vol 11 (5) ◽  
pp. 2144
Author(s):  
Timothy Sands
Keyword(s):  
Artificial Intelligence ◽  
State Of The Art ◽  
Underwater Vehicles ◽  
Modeling Method ◽  
Superior Performance ◽  
Alternative Methods ◽  
Self Awareness ◽  
Square Wave ◽  
Unmanned Underwater Vehicles ◽  
Art Methods

Many research manuscripts propose new methodologies, while others compare several state-of-the-art methods to ascertain the best method for a given application. This manuscript does both by introducing deterministic artificial intelligence (D.A.I.) to control direct current motors used by unmanned underwater vehicles (amongst other applications), and directly comparing the performance of three state-of-the-art nonlinear adaptive control techniques. D.A.I. involves the assertion of self-awareness statements and uses optimal (in a 2-norm sense) learning to compensate for the deleterious effects of error sources. This research reveals that deterministic artificial intelligence yields 4.8% lower mean and 211% lower standard deviation of tracking errors as compared to the best modeling method investigated (indirect self-tuner without process zero cancellation and minimum phase plant). The improved performance cannot be attributed to superior estimation. Coefficient estimation was merely on par with the best alternative methods; some coefficients were estimated more accurately, others less. Instead, the superior performance seems to be attributable to the modeling method. One noteworthy feature is that D.A.I. very closely followed a challenging square wave without overshoot—successfully settling at each switch of the square wave—while all of the other state-of-the-art methods were unable to do so.

A Systematic Literature Review of the EFQM Excellence Model from 1991 to 2019

1970 ◽  
Vol 2 (2) ◽  
pp. 11-15
Author(s):  
Muhammad Yousaf ◽  
Petr Bris
Keyword(s):  
Quality Management ◽  
Data Collection ◽  
Literature Review ◽  
Systematic Literature Review ◽  
Quantitative Research ◽  
Web Of Science ◽  
State Of The Art ◽  
Future Research ◽  
European Foundation ◽  
The Subject

A systematic literature review (SLR) from 1991 to 2019 is carried out about EFQM (European Foundation for Quality Management) excellence model in this paper. The aim of the paper is to present state of the art in quantitative research on the EFQM excellence model that will guide future research lines in this field. The articles were searched with the help of six strings and these six strings were executed in three popular databases i.e. Scopus, Web of Science, and Science Direct. Around 584 peer-reviewed articles examined, which are directly linked with the subject of quantitative research on the EFQM excellence model. About 108 papers were chosen finally, then the purpose, data collection, conclusion, contributions, and type of quantitative of the selected papers are discussed and analyzed briefly in this study. Thus, this study identifies the focus areas of the researchers and knowledge gaps in empirical quantitative literature on the EFQM excellence model. This article also presents the lines of future research.

Damage observations and remedial options for approximately 1500 legged and flat-based liquid storage tanks following the 2016 Kaikōura earthquake

Structures ◽  
2020 ◽  
Vol 24 ◽  
pp. 357-376 ◽  
Author(s):  
Mohsen Yazdanian ◽  
Jason M. Ingham ◽  
Will Lomax ◽  
Regan Wood ◽  
Dmytro Dizhur
Keyword(s):  
Storage Tanks ◽  
Liquid Storage ◽  
Kaikoura Earthquake

Towards Interconnected Blockchains

2021 ◽  
Vol 54 (7) ◽  
pp. 1-39
Author(s):  
Ankur Lohachab ◽  
Saurabh Garg ◽  
Byeong Kang ◽  
Muhammad Bilal Amin ◽  
Junmin Lee ◽  
...  
Keyword(s):  
State Of The Art ◽  
The State ◽  
Future Research ◽  
Missing Link ◽  
Layered Architecture ◽  
Blockchain Technology ◽  
Wide Scale ◽  
Effective Development ◽  
Insight Into ◽  
Game Changer

Unprecedented attention towards blockchain technology is serving as a game-changer in fostering the development of blockchain-enabled distinctive frameworks. However, fragmentation unleashed by its underlying concepts hinders different stakeholders from effectively utilizing blockchain-supported services, resulting in the obstruction of its wide-scale adoption. To explore synergies among the isolated frameworks requires comprehensively studying inter-blockchain communication approaches. These approaches broadly come under the umbrella of Blockchain Interoperability (BI) notion, as it can facilitate a novel paradigm of an integrated blockchain ecosystem that connects state-of-the-art disparate blockchains. Currently, there is a lack of studies that comprehensively review BI, which works as a stumbling block in its development. Therefore, this article aims to articulate potential of BI by reviewing it from diverse perspectives. Beginning with a glance of blockchain architecture fundamentals, this article discusses its associated platforms, taxonomy, and consensus mechanisms. Subsequently, it argues about BI’s requirement by exemplifying its potential opportunities and application areas. Concerning BI, an architecture seems to be a missing link. Hence, this article introduces a layered architecture for the effective development of protocols and methods for interoperable blockchains. Furthermore, this article proposes an in-depth BI research taxonomy and provides an insight into the state-of-the-art projects. Finally, it determines possible open challenges and future research in the domain.

scholarly journals Utilization of Eco-Friendly Waste Generated Nanomaterials in Water-Based Drilling Fluids; State of the Art Review

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4171
Author(s):  
Rabia Ikram ◽  
Badrul Mohamed Jan ◽  
Akhmal Sidek ◽  
George Kenanakis
Keyword(s):  
State Of The Art ◽  
Superior Performance ◽  
Future Research ◽  
Drilling Fluids ◽  
Drill Cuttings ◽  
Environmental Friendly ◽  
Water Based ◽  
Drilling Operations ◽  
Filtration Properties

An important aspect of hydrocarbon drilling is the usage of drilling fluids, which remove drill cuttings and stabilize the wellbore to provide better filtration. To stabilize these properties, several additives are used in drilling fluids that provide satisfactory rheological and filtration properties. However, commonly used additives are environmentally hazardous; when drilling fluids are disposed after drilling operations, they are discarded with the drill cuttings and additives into water sources and causes unwanted pollution. Therefore, these additives should be substituted with additives that are environmental friendly and provide superior performance. In this regard, biodegradable additives are required for future research. This review investigates the role of various bio-wastes as potential additives to be used in water-based drilling fluids. Furthermore, utilization of these waste-derived nanomaterials is summarized for rheology and lubricity tests. Finally, sufficient rheological and filtration examinations were carried out on water-based drilling fluids to evaluate the effect of wastes as additives on the performance of drilling fluids.

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