Validation of Shiphandling Simulation Models

2011 ◽  
Author(s):  
Tor E. Berg ◽  
Edvard Ringen
Keyword(s):  
Simulation Model ◽  
Numerical Models ◽  
Real Life ◽  
Simulation Models ◽  
Test Scheme ◽  
High Quality ◽  
Simulation Tools ◽  
Benchmark Study ◽  
Actual Application

This paper describes the need for improved methods for validating numerical models used in shiphandling simulators. Such models vary in complexity, from rather simplistic models used for initial shiphandling training at maritime training centers to high-quality models used in the study of advanced marine operations. High-quality simulation models are also used in investigations of maritime accidents such as collisions and groundings. The SIMMAN 2008 conference presented the results of benchmarking studies of simulation tools currently used by research institutes, universities and training centers around the world. Many of these tools employ models based on numerical calculations using methods based on potential or viscous fluid flow, experiments using scale ship models (free running or captive) or semi empirical expressions based on regression analysis of previous model tests. The organizers of SIMMAN 2008 made the hull characteristics of certain ship types available for a comparative study of simulation maneuvering models. The outcome of the benchmark study (using IMO standard maneuvers as case study maneuvers) showed that simulated results varied significantly. In the opinion of the authors, there is an urgent need for new validation studies. The first part of this paper discusses the concepts of simulation model fidelity, verification and validation and the present guidelines issued by ITTC for validation of maneuvering simulation models. The second part looks at the outcomes of the SIMMAN 2008 conference and describes MARINTEK’s contribution to the benchmark study. The use of real-world measurements in model validation is briefly discussed. The need for registration of actual test conditions, as well as the types of tests that should be included in a test scheme, are presented. Finally, the authors discuss validation requirements with respect to the actual application of the selected simulation model as an engineering tool that can be transferred to training simulators used by maritime training centers. It is assumed that simplified simulation models may reduce the quality of simulator based training for ship officers. It is believed that increased quality of simulator model will improve the transfer of training from simulators to real life operations and remove some of the uncertainties related to investigation of maritime accidents.

scholarly journals The contribution of the Italian residents in neurology to the COVID-19 crisis: admirable generosity but neurological training remains their priority

2021 ◽  
Author(s):  
Cristina Tassorelli ◽  
Vincenzo Silani ◽  
Alessandro Padovani ◽  
Paolo Barone ◽  
Paolo Calabresi ◽  
...  
Keyword(s):  
Clinical Training ◽  
Real Life ◽  
Healthcare Management ◽  
Point Of View ◽  
Research Activity ◽  
High Quality ◽  
Research Activities ◽  
Italian Regions ◽  
Training And Research

Abstract Background The coronavirus disease 2019 (COVID-19) pandemic has severely impacted the Italian healthcare system, underscoring a dramatic shortage of specialized doctors in many disciplines. The situation affected the activity of the residents in neurology, who were also offered the possibility of being formally hired before their training completion. Aims (1) To showcase examples of clinical and research activity of residents in neurology during the COVID-19 pandemic in Italy and (2) to illustrate the point of view of Italian residents in neurology about the possibility of being hired before the completion of their residency program. Results Real-life reports from several areas in Lombardia—one of the Italian regions more affected by COVID-19—show that residents in neurology gave an outstanding demonstration of generosity, collaboration, reliability, and adaptation to the changing environment, while continuing their clinical training and research activities. A very small minority of the residents participated in the dedicated selections for being hired before completion of their training program. The large majority of them prioritized their training over the option of earlier employment. Conclusions Italian residents in neurology generously contributed to the healthcare management of the COVID-19 pandemic in many ways, while remaining determined to pursue their training. Neurology is a rapidly evolving clinical field due to continuous diagnostic and therapeutic progress. Stakeholders need to listen to the strong message conveyed by our residents in neurology and endeavor to provide them with the most adequate training, to ensure high quality of care and excellence in research in the future.

Novel Dielectric Stack Actuators for Dynamic Applications

2012 ◽  
Author(s):  
Sven Herold ◽  
William Kaal ◽  
Tobias Melz
Keyword(s):  
Simulation Model ◽  
Surface Resistance ◽  
Design Concept ◽  
Metal Electrodes ◽  
High Quality ◽  
Complex Material ◽  
Simulation Results ◽  
Actuator Design ◽  
Load Conditions

In order to realize dielectric elastomer stack actuators suitable for dynamic applications a new actuator design with rigid, perforated electrodes is developed. The low surface resistance of the metal electrodes predestines this concept for dynamic applications where higher currents are present. Detailed numerical analyses are performed to show the potential of this approach, to study the complex material deformation and to optimize the aperture geometry. A multilayer stack actuator is then manufactured and characterized experimentally under various load conditions to gain suitable parameters for a parametrized model. It is subsequently used to attenuate vibrations of a truss structure. By careful adjusting the parameters it functions both as passive absober and as actuator. A comparison of experimental and simulation results proves the high quality of the simulation model. The work shows the great potential of the new design concept for future applications especially in the field of smart structures.

scholarly journals Effect of the sorting track profile change on the it’s occupancy quality at train humping

2018 ◽  
Vol 216 ◽  
pp. 02012 ◽  
Author(s):  
Konstantin Kornienko ◽  
Sergei Bessonenko
Keyword(s):  
Simulation Model ◽  
High Quality ◽  
Run Off ◽  
Profile Correction ◽  
Probability Of Collision ◽  
Profile Change

To increase the hump yard capacity, it is necessary to ensure high quality of sorting track occupancy. The purpose of this paper is to study the effect of changing the track profile on the quality of its occupancy. The simulation model developed for occupancy of sorting tracks based on the calculation of the speed of the cut and taking the following into consideration was used for the study: the possibility of starting the cut movement after a stop, errors in operation of the devices in charge of the speed of releasing the cut to the track, the possibility of displacement of the cars when the next cut collides with them. A real profile of the sorting facility track was analyzed as an example of it. It was determined that the profile caused strong effect on the track occupancy quality. The sagging of the profile causes an increase in the probability of collision of the cuts with exceeding the permissible speed. An increase in the up-gradient reduces the range of the run-off distance, which in turn causes an increase in the number of car back-ins. Profile correction will allow increasing the track occupancy quality.

Efficiently Utilizing a Low Grade and Complex Copper Ore by Flotation

2013 ◽  
Vol 734-737 ◽  
pp. 929-934
Author(s):  
Qi Nie ◽  
Xiao Si Zhou ◽  
Fen Lan Peng ◽  
Xu Shen ◽  
Zhi Zhang Li
Keyword(s):  
Yunnan Province ◽  
Copper Recovery ◽  
Test Scheme ◽  
Low Grade ◽  
High Quality ◽  
Copper Ore ◽  
Copper Concentrate ◽  
Main Factors ◽  
Complex Copper

Based on the analysis of the properties of the copper ore from Jinggu area in Yunnan province, a suitable technical route was presented for processing of eligible copper concentrate and the main factors i.e. grinding fineness, Na2S dosage and collector dosage, affecting the quality of roughing concentration was investigated. On this basis, a close-circuit flotation test scheme was preceded, which obtained a high quality copper concentrate with Cu grade of 16.08%, copper recovery of 58.52%. The recovery of copper concentrate is much lower than the Cu recovery of roughing concentrate from the condition experiments. This may be contributed to the fact that fine slime carried by middling worsens the separation of copper minerals and gangues. The Mo was enriched in concentrate, which is significantly considered to recovery in further work.

scholarly journals Answering the Min-Cost Quality-Aware Query on Multi-Sources in Sensor-Cloud Systems

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4486 ◽  
Author(s):  
Mohan Li ◽  
Yanbin Sun ◽  
Yu Jiang ◽  
Zhihong Tian
Keyword(s):  
Low Cost ◽  
Real Life ◽  
Quality Data ◽  
Parameter Setting ◽  
Multiple Sources ◽  
High Quality ◽  
High Quality Data ◽  
Real Life Data ◽  
Sensor Cloud

In sensor-based systems, the data of an object is often provided by multiple sources. Since the data quality of these sources might be different, when querying the observations, it is necessary to carefully select the sources to make sure that high quality data is accessed. A solution is to perform a quality evaluation in the cloud and select a set of high-quality, low-cost data sources (i.e., sensors or small sensor networks) that can answer queries. This paper studies the problem of min-cost quality-aware query which aims to find high quality results from multi-sources with the minimized cost. The measurement of the query results is provided, and two methods for answering min-cost quality-aware query are proposed. How to get a reasonable parameter setting is also discussed. Experiments on real-life data verify that the proposed techniques are efficient and effective.

A Circuit Simulator Applicable to Fault Simulation

2011 ◽  
Vol 58-60 ◽  
pp. 1287-1293
Author(s):  
Guang Yan Zhao ◽  
Yu Feng Sun ◽  
Qing Tang
Keyword(s):  
Simulation Model ◽  
Simulation Analysis ◽  
Circuit Simulation ◽  
Fault Simulation ◽  
Simulation Models ◽  
Fault Models ◽  
Logical Variable ◽  
Simulation Tools ◽  
Circuit Simulator ◽  
Basic Functions

In view of the demand of circuit fault simulation analysis, a novel circuit simulator for fault simulation was designed to overcome the shortcomings of traditional circuit simulation tools in fault simulation. The principles and method of this simulator were proposed, which focus on the realization of the basic functions and weakens detail characteristics. Based on the method, the components simulation models and fault models with the combination of the numerical variable with logical variable were built. Moreover, the implementation algorithm and simulation flow were introduced to show how to simulate a circuit based on this simulation model. At last, an example was simulated to verify the feasibility of this method. It is shown that, this circuit simulator will become a valuable tool for the circuit fault simulation and analysis.

A Simulation-Based Methodology for Evaluating the Factors on Ship Emergency Evacuation

2017 ◽  
Vol 159 (A4) ◽  
Author(s):  
P A Sarvari ◽  
E Cevikcan
Keyword(s):  
Simulation Model ◽  
Real Life ◽  
Emergency Situation ◽  
Simulation Models ◽  
Emergency Evacuation ◽  
Time Difference ◽  
Dominant Factor ◽  
Evacuation Time ◽  
Simulation Based ◽  
First Time

There are many hazards on a ship that makes an emergency evacuation process inevitable. Providing safe and effective evacuation of passengers from ships in an emergency situation becomes critical. Handling a real ship evacuation practice is often unaffordable as modelling such an environment is very expensive and may cause severe distress to participants. As an alternative, simulation models have been used to overwhelm the issue above in recent years. Therefore, this paper proposes a novel simulation-based methodology for evaluating the effect of factors including physical as well as psychological passenger characteristics and routeing systematic on emergency evacuation process for public marine transportation. A detailed questionnaire has been conducted in this work to reflect passenger characteristics on simulation model in a more realistic manner. Also, a new routeing systematic is developed to provide an efficient evacuation procedure. As another contribution, a novel grid-based approach where the meshed discretized nodes can contain more than one passenger is proposed in simulation model for the first time. Then, a statistical analysis is included within the methodology to assess the importance level of each factor on evacuation time. The proposed methodology is applied to a real life Ro-Ro ferry. A validation protocol based on IMO regulations is conducted and confirmed the effectiveness of the suggested simulation model. The simulation of different scenario types have indicated the influencing factors in a ship emergency evacuation. According to results, passenger characteristics has been identified as the most dominant factor on evacuation performance. The highest evacuation time difference has been observed for different levels of weight attribute. Moreover, it is concluded that the consideration of load utilization balancing among evacuation systems for routeing decreases evacuation time significantly. Finally, significant evacuation time difference between grid approaches have been demonstrated.

Accuracy of French census population estimates

2021 ◽  
pp. 1-20
Author(s):  
Lionel Espinasse ◽  
Vincent Le Palud ◽  
Julie Prévot ◽  
Gwenna ël Solard ◽  
Lucile Vanotti
Keyword(s):  
Response Rate ◽  
Process Development ◽  
Real Life ◽  
Population Estimates ◽  
Population Census ◽  
High Quality ◽  
The Many ◽  
Extensive Involvement ◽  
Quality Of The Population

The French population census method evolved in the early 2000s. Few studies have been published on the quality of the population estimates produced by this new method, apart from a few observing sample variance resulting from the introduction of a survey in large municipalities. However, the French census is subject to numerous quality controls throughout the process: development of a housing register, preparation of the collection, the collection itself and the post-collection, adjustment and estimation operations. The extensive involvement of stakeholders (municipalities and INSEE) in the preparation and conduct of the census leads to a very good understanding of the process. The many checks carried out throughout the process guarantee that the estimates produced are of a high quality. In addition, the census benefits from a very low non-response rate (3.9% in 2019). However, some features are not yet well known. Although many instructions are included in questionnaires, the answers given by enumerated persons are imperfect due to misunderstandings, an inability to adapt questions to real-life situations, or deliberately incorrect answers.

scholarly journals Modelling an enterprise global IP network with multimedia services

2019 ◽  
Vol 6 ◽  
pp. 45-53
Author(s):  
Yoana Ivanova
Keyword(s):  
Simulation Model ◽  
Simulation Software ◽  
Multimedia Content ◽  
Multimedia Services ◽  
High Quality ◽  
Operational Costs ◽  
Ip Network ◽  
Packet Tracer ◽  
Quality Of Voice

The aim of this paper is building a simulation model of an enterprise global IP network with multimedia services using the network simulation software Cisco Packet Tracer. They are examined protocols for the realization of the VoIP service and providing multimedia content to end users with guaranteed high quality of voice and multimedia services. The result of the research is a simulation model implemented using Cisco networking devices that are selected due to their advantages compared to other device models. The applied contributions are expressed in reducing the operational costs and ensuring reliable protection and stability when the load of the network is maximum.

scholarly journals IMULATION MODELING OF PROCESSES OF UNIT-ASSEMBLY PRODUCTION OF AIRCRAFT PRODUCTS

2021 ◽  
Vol 23 (1) ◽  
pp. 60-66
Author(s):  
R.A. Salaev ◽  
◽  
A.A. Fedorov ◽  
A.V. Salaeva ◽  
◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Simulation Model ◽  
Simulation Models ◽  
Economic Costs ◽  
Labor Costs ◽  
Simulation Tools ◽  
Production Processes ◽  
Total Labor ◽  
Production Areas ◽  
Assembly Production

The article presents a universal simulation model of aggregate and Assembly production processes based on IDEF0 methods and numerical modeling methods. The problem statement is formed as follows: it is necessary to analyze the existing simulation tools, structure the Assembly production processes into separate classes and subclasses, describe the processes using the IDEF0 method, create a simulation model of the aggregate-Assembly production process with a link between economic and labor costs. The total labor intensity of Assembly processes and economic costs were considered as optimization criteria in this study. Numerical modeling and optimization of workflow parameters were performed in the AnyLogic simulation environment. The obtained simulation models can be used in the future in the management system of aviation enterprises, as well as in other production areas where the product is a complex system.

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