scholarly journals Smoothing warships movements based on wavelets

2013 ◽  
Vol 6 (12) ◽  
pp. 51
Author(s):  
J.M. Riola ◽  
J.M. Girón ◽  
J.J. Díaz
Keyword(s):  
Weather Conditions ◽  
Point Of View ◽  
Ship Motions ◽  
Main Question ◽  
Measurement Systems ◽  
Quiescent Period ◽  
Wave Measurement ◽  
Key Issues ◽  
The Waves ◽  
Initial Measurement

In seakeeping terminology, the Quiescent Period is known as the period of calm in rough waters to allow the ship to perform operations such as landing aircrafts and unmanned aerial vehicles (UAVs), aswell as the entry of landing crafts in the basin. Quiescence refers to the interval of time where all ship motions are within acceptable limits to perform a desired activity. Among the key issues for Quiescent Period Prediction is to be able to measure waves from a suitable distance and predict ship motions in response to waves encountered; both aspects are crucial and must be taken into account. Many of the opearations performed at sea are carried under severe weather conditions, as a result of this situation there is a need to determine this called “window of opportunity” that allows carrying them out. The paper aims to explain from the point of view of Quiescent Period Prediction, the most promising wave measurement systems, which are currently based on radar, but the main question is that if we want predictions a few seconds ahead, it will be appropriate to measure waves at a distance of some hundreds of meters, describing the new mathematical model based on wavelets in determining the spread of the waves from their initial measurement until they reach the vessel.

scholarly journals Simulation Modeling of a Ship Propulsion System in Wavesfor Control Purposes

2021 ◽  
Vol 10 (1) ◽  
pp. 36
Author(s):  
Maria Acanfora ◽  
Marco Altosole ◽  
Flavio Balsamo ◽  
Luca Micoli ◽  
Ugo Campora
Keyword(s):  
Dynamic Instability ◽  
Dynamic Performance ◽  
Weather Conditions ◽  
Propulsion System ◽  
Point Of View ◽  
Ship Motions ◽  
Electric Motors ◽  
Parametric Roll ◽  
Linear Behavior ◽  
Engine Dynamic

The article deals with a simulation approach to the representation of the ship motions in waves, interacting with the propulsion system behavior (diesel engine and propeller). The final goal is the development of a simulator, as complete as possible, that allows the analysis of the main engine thermodynamics in different sea conditions, also in the unfavorable event of dynamic instability of the hull, and the correct management of the other propulsion components. This latter aspect is particularly interesting in some of the last new energy solutions for decarbonization of ships, concerning, for example, auxiliary electric motors, powered by batteries, to support the traditional diesel-mechanical propulsion (especially in heavy weather conditions). From this point of view, a proper analysis of the engine dynamic performance, affected by particular sea states, is fundamental for a smart management and control of shaft generators/auxiliary electric motors, batteries, etc. To this end, the work presents and highlights the main features of a ship simulator, suitable for the study of the new propulsion solutions that are emerging in maritime transport. Some representative results will point out the complex non-linear behavior of the propulsion plant in waves. Moreover, a parametric roll scenario will be investigated, in order to highlight the capability of the conceived simulator in modeling the effects of the dynamic instability of the hull on the propulsion plant.

Effectiveness of Flood Protection Project Valuation Methods

2015 ◽  
Vol 10 (3) ◽  
pp. 275-289
Author(s):  
Tadeusz Liziński ◽  
Marcin Bukowski ◽  
Anna Wróblewska
Keyword(s):  
Essential Element ◽  
Weather Conditions ◽  
Point Of View ◽  
Flood Protection ◽  
Costs And Benefits ◽  
Protection Measures ◽  
Investment Projects ◽  
Market Values ◽  
Project Valuation ◽  
The Subject

Projects for flood protection are increasingly the subject of investment projects in the field of water management. This is related to the increasing frequency of worldwide threats caused by extreme weather conditions, including extremely high rainfall causing floods. Technical and nontechnical flood protection measures are also increasing in importance. In the decision-making process, it is necessary to take into account both the costs and benefits of avoiding losses, including an analysis of social benefits, whose valuation of non-market goods is an essential element. A comprehensive account of projects in the field of flood protection based on the estimated costs and benefits of the investment allows the economic efficiency from a general social point of view to be determined. Previous evaluations of the effectiveness of investment projects have mainly taken into account only categories and market values. The aim of the article is to identify the possibilities to expand the values of non-market assessments and categories formulated on the basis of the theoretical economics of the environment. 

Remembering From-the-Outside

2018 ◽  
Author(s):  
Christopher McCarroll
Keyword(s):  
Empirical Evidence ◽  
Point Of View ◽  
Philosophical Analysis ◽  
Visual Perspective ◽  
Observer Perspective ◽  
The Status ◽  
Key Issues ◽  
Way Of Thinking

This chapter sets out some key issues related to a philosophical analysis of point of view in memory. It does so by looking at examples of psychological, philosophical, and literary accounts of the phenomenon, as well as examples of the author’s own observer perspective memories. The chapter provides an overview of some of the empirical evidence related to visual perspective in memory. Despite these consistent empirical findings, however, a number of doubts and misconceptions about remembering from-the-outside still linger, especially concerning the status of observer perspectives in memory. This chapter outlines some of the skepticism to the possibility of remembering from-the-outside and points to a possible diagnosis of why such skepticism arises. This chapter points to a way of thinking about memory—to be developed through the course of the book—which eases the worries about remembering from-the-outside.

scholarly journals Design and Field Validation of a Low Power Wireless Sensor Node for Structural Health Monitoring

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1050
Author(s):  
Federico Zanelli ◽  
Francesco Castelli-Dezza ◽  
Davide Tarsitano ◽  
Marco Mauri ◽  
Maria Laura Bacci ◽  
...  
Keyword(s):  
Low Power ◽  
Sensor Node ◽  
Weather Conditions ◽  
Point Of View ◽  
Design Stage ◽  
Monitoring Systems ◽  
Wireless Sensor Node ◽  
Process Data ◽  
Fatigue Life Estimation ◽  
Remaining Fatigue Life

Smart monitoring systems are currently gaining more attention and are being employed in several technological areas. These devices are particularly appreciated in the structural field, where the collected data are used with purposes of real time alarm generation and remaining fatigue life estimation. Furthermore, monitoring systems allow one to take advantage of predictive maintenance logics that are nowadays essential tools for mechanical and civil structures. In this context, a smart wireless node has been designed and developed. The sensor node main tasks are to carry out accelerometric measurements, to process data on-board, and to send wirelessly synthetic information. A deep analysis of the design stage is carried out, both in terms of hardware and software development. A key role is played by energy harvesting integrated in the device, which represents a peculiar feature and it is thanks to this solution and to the adoption of low power components that the node is essentially autonomous from an energy point of view. Some prototypes have been assembled and tested in a laboratory in order to check the design features. Finally, a field test on a real structure under extreme weather conditions has been performed in order to assess the accuracy and reliability of the sensors.

scholarly journals Quantifying wave measurement differences in historical and present wave buoy systems

2021 ◽  
Author(s):  
Robert Edward Jensen ◽  
Val Swail ◽  
Richard Harry Bouchard
Keyword(s):  
Complex Nature ◽  
Frequency Spectra ◽  
Measurement Systems ◽  
Wave Measurements ◽  
Directional Sensors ◽  
Wave Measurement ◽  
Western Us ◽  
Directional Wave ◽  
Wind Sea ◽  
Wave Properties

AbstractAn intra-measurement evaluation was undertaken, deploying a NOMAD buoy equipped with three National Data Buoy Center and two Environment and Climate Change Canada-AXYS sensor/payload packages off Monterey, California; a Datawell Directional Waverider buoy was deployed within 19 km of the NOMAD site. The six independent wave measurement systems reported hourly estimates of the frequency spectra, and when applicable, the four Fourier directional components. The integral wave parameters showed general agreement among the five sensors compared to the neighboring Datawell Directional Waverider, with the Inclinometer and the Watchman performing similarly to the more sophisticated 3DMG, HIPPY, and Triaxys sensor packages. As the Hm0 increased, all but the Inclinometer were biased low; however, even the Watchman reported reasonable wave measurements up to about 6–7 m, after which the Hm0 becomes negatively biased up to about a meter, comparable to previous studies. The parabolic fit peak spectral wave period, Tpp, results showed a large scatter, resulting from the complex nature of multiple swell wave systems compounded by local wind-sea development, exacerbated by a variable that can be considered as temporally unstable. The three directional sensors demonstrated that NOMAD buoys are capable of measuring directional wave properties along the western US coast, with biases of about 6 to 9 deg, and rms errors of approximately 30 deg. Frequency spectral evaluations found similarities in the shape, but a significant under estimation in the high frequency range. The results from slope analyses also revealed a positive bias in the rear face of the spectra, and a lack of invariance in frequency as suggested by theory.

Optimization of Restoration Paths of Power System after Blackout

2013 ◽  
Vol 347-350 ◽  
pp. 1467-1472
Author(s):  
Wen Wei Huang ◽  
Gang Yao ◽  
Xiao Yan Qiu ◽  
Nian Liu ◽  
Guang Tang Chen
Keyword(s):  
Power System ◽  
Transmission Lines ◽  
Reactive Power ◽  
Minimum Spanning Tree ◽  
Operation Time ◽  
Combinatorial Problem ◽  
Weather Conditions ◽  
Recovery Process ◽  
Point Of View ◽  
Improved Genetic Algorithm

Optimization of restoration paths of power system after blackout is a multi-stage, multi-target, multi-variable combinatorial problem in the power system restoration. This paper presents a reasonable model and effectually method. The proposed model is considered as a typical partial minimum spanning tree problem from the mathematical point of view which considering all kinds of constraints. Improved data envelopment analysis (DEA) was used to get the weight which considering line charging reactive power, weather conditions, operation time and betweenness of transmission lines. The improved genetic algorithm method is employed to solve this problem. Finally, an example is given which proves the strategy of the line restoration can effectively handle the uncertainty of the system recovery process, to guarantee the system successfully restored after the catastrophic accidents.

تشخيص الخصائص الشخصية للمهارات الناعمة دراسة استطلاعية لآراء عينة من القيادات الادارية في دائرة صحة ديالى

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
ناجي محمود ◽  
عدنان جاسم
Keyword(s):  
Soft Skills ◽  
Statistical Treatment ◽  
Main Tool ◽  
Personal Characteristics ◽  
Health Department ◽  
Point Of View ◽  
Main Question ◽  
Communication Processes ◽  
Administrative Leaders ◽  
Health Organization

Contemporary organizations have directed their attention and focus on the role of the skills that their administrative leaders have in order to apply them to the areas of the organization and in a way that serves its objectives, represents the goal of the study to diagnose the personal characteristics of the soft skills in the researched health organization. Hence, the study problem arises with the main question which is: Do the respondents of the study sample regarding soft skills differ according to the personal or demographic characteristics of the researched organization? For the purpose of achieving the objectives of the study and answering its questions, the descriptive analytical approach was used, and the study adopted the questionnaire as a main tool for collecting data. The study was taken from the Diyala Health Department as a community, as (180) questionnaires were distributed to the administrative leaders working in Diyala Health Department, and (160) questionnaires were retrieved from them, and after data collection and statistical treatment, the study reached a number of conclusions, the most important of which are. There is agreement between the opinions of the sample members about soft skills with a high degree of evaluation from the point of view of the administrative leaders in the Diyala Health Department. One of the most prominent recommendations was to improve and develop communication processes between workers in the researched health organization.

scholarly journals Observation of mesospheric gravity waves at Comandante Ferraz Antarctica Station (62° S)

2009 ◽  
Vol 27 (6) ◽  
pp. 2593-2598 ◽  
Author(s):  
J. V. Bageston ◽  
C. M. Wrasse ◽  
D. Gobbi ◽  
H. Takahashi ◽  
P. B. Souza
Keyword(s):  
Gravity Waves ◽  
Weather Conditions ◽  
Propagation Direction ◽  
Cyclonic Activity ◽  
Wave Source ◽  
Cold Fronts ◽  
Wave Velocities ◽  
Orographic Forcing ◽  
Sky Imager ◽  
The Waves

Abstract. An airglow all-sky imager was operated at Comandante Ferraz Antarctica Station (62.1° S, 58.4° W), between April and October of 2007. Mesospheric gravity waves were observed using the OH airglow layer during 43 nights with good weather conditions. The waves presented horizontal wavelengths between 10 and 60 km and observed periods mainly distributed between 5 and 20 min. The observed phase speeds range between 5 m/s and 115 m/s; the majority of the wave velocities were between 10 and 60 m/s. The waves showed a preferential propagation direction towards the southwest in winter (May to July), while during spring (August to October) there was an anisotropy with a preferential propagation direction towards the northwest. Unusual mesospheric fronts were also observed. The most probable wave source could be associated to orographic forcing, cold fronts or strong cyclonic activity in the Antarctica Peninsula.

A Probabilistic Study of the Simultaneous Effect of Ship Motions on the Cargo Shifting Onboard

1996 ◽  
Vol 33 (01) ◽  
pp. 25-34
Author(s):  
Jianbo Hua
Keyword(s):  
Transfer Functions ◽  
Simulation Method ◽  
Point Of View ◽  
Roll Angle ◽  
Ship Motions ◽  
Vertical Acceleration ◽  
Simultaneous Effect ◽  
Strip Theory ◽  
Probabilistic Study ◽  
Mean Wave Period

Cargo movement aboard ship can occur even in waves that produce only moderate rolling motion. It is caused when the simultaneous effect of vertical acceleration, horizontal acceleration and roll motion on the cargo onboard—defined as the equivalent roll angle—becomes sufficiently large for the problem to develop. In this paper, an analytical expression is derived for the probabilistic calculation of the equivalent roll angle, which has a nonlinear characteristic. Also, a so-called indirect time-domain simulation method is described for calculating the problem. Both methods are based on motion transfer functions calculated according to strip theory. The calculations presented here show both methods to be in good agreement. A probabilistic calculation of the equivalent roll angle of a roll-on/roll-off (RO/RO) ship is carried out using the two methods and focusing on parameters such as significant wave height, mean wave period, ship speed, and relative course angle. It is proved from the point of view of probability that the nonlinearity of equivalent roll angle results in a magnifying effect on its extreme value. The calculation shows also that in severe wave conditions large peak values of equivalent roll greater than 35 deg can be experienced by the studied RO/RO ship.

Smart Water Level Monitoring System for Farmers

2019 ◽  
pp. 213-228
Author(s):  
Nalina Suresh ◽  
Valerianus Hashiyana ◽  
Victor Panduleni Kulula ◽  
Shreekanth Thotappa
Keyword(s):  
Water Level ◽  
Monitoring System ◽  
Cost Effective ◽  
Weather Conditions ◽  
Water Levels ◽  
Measurement Systems ◽  
Smart Water ◽  
Level Measurement ◽  
Level Monitoring ◽  
Water Level Monitoring

With advancement in technology and ever-changing weather conditions, accurate and affordable water level measurement systems has become necessary for farmers. This therefore brings about the need for a system incorporating the use of IoT technology that will monitor water levels at a cost-effective price with accurate and dependable results. The prototype will monitor water levels on a regular basis and the data captured will be stored in a database to help farmers improve the way they manage their water resource. Farmers will be able to monitor the water levels from any location at any given time. This chapter focuses on a Smart Water Level Monitoring System for Farmers and provides a smart way to manage water resources on farms in the most cost-effective and convenient manner for farmers.

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