Real-Time Hybrid Testing for Marine Structures: Challenges and Strategies

2013 ◽  
Author(s):  
Valentin Chabaud ◽  
Sverre Steen ◽  
Roger Skjetne
Keyword(s):  
Real Time ◽  
Scale Model ◽  
Force Estimation ◽  
Time Step ◽  
Hybrid Testing ◽  
Data Measurement ◽  
Main Challenge ◽  
Set Up ◽  
The One

Within the field of hydrodynamics, it is fairly easy to find examples of model tests whose performance is impaired by only a subpart of the whole system, which may not be the one of interest. Real-time hybrid testing (RTHT) overcomes this issue by performing scale model testing only on a subpart of the whole structure, the remainder being simulated numerically. The loads acting on the virtual substructure are calculated from online-measured motions of the physical substructure and actuated back on the latter in real-time. RTHT involves data measurement, filtering, force estimation, motion observing and force actuation. The main challenge is to fit all of those items into one time step. A simple case study is suggested. It consists in a linearized one degree of freedom floating wind turbine, whose floating substructure is physically tested while wind loads are numerically simulated and actuated. Design rules to build the corresponding RTHT set up are then presented.

scholarly journals WHAT IT TAKES TO INNOVATE: THE EXPERIENCE OF PRODUCING AN ONLINE, REAL-TIME CASE STUDY

2019 ◽  
Vol 11 (4) ◽  
Author(s):  
James Theroux
Keyword(s):  
Real Time ◽  
Teaching Methods ◽  
Recent Attempt ◽  
The Internet ◽  
Case Method ◽  
Business Courses ◽  
New Type ◽  
The One ◽  
Instantaneous Distribution

The case method can be classified as a type of experiential learning because students treat the problem in the case as if it were real and immediate. Until the Internet there was no practical way for cases to actually be real and immediate. The Internet makes possible instantaneous distribution of cases, and it makes possible their creation in real time. This article describes a recent attempt to use the Internet to bring business reality to business courses, and to facilitate communication among instructors, students, and the case company. It explores the challenges and difficulties involved in producing a new type of case study, and it assesses the feasibility of doing so on a regular basis. The goal of the author is to stimulate a dialog about how the Internet can be used to move forward all of our teaching methods, but especially the one that is prominent in schools of business: the case method.

A case study using narrative therapy to “rewrite” the non-conforming reputation of a high school student

2001 ◽  
Vol 11 ◽  
pp. 131-140
Author(s):  
Miguel Fernandez
Keyword(s):  
High School ◽  
Narrative Therapy ◽  
Sense Of Self ◽  
Male Student ◽  
School Personnel ◽  
Young Person ◽  
Negative Effects ◽  
Set Up ◽  
The One

This paper begins with a brief description of research stating that adolescents in schools generally pursue reputations that are either nonconforming or conforming. This is usually achieved through the development of goals specific to each type of reputation. Essential to the maintenance of a reputation is the recruitment of an audience. It is also proposed by researchers that intervention by school personnel becomes crucial when trying to counteract the negative effects of a nonconforming Using a case study, this paper investigates the use of Narrative Therapy with a 15-year-old male student in a high school who had developed a nonconforming reputation. A three-year-old nonconforming reputation is put through a Narrative framework that challenges “its” goals and reason for being. As the sessions progress, there is a sense that this young person is beginning to move towards a more preferred sense of self that is potentially different from the one set-up by the nonconforming reputation. This is achieved by using a Narrative style dialogical approach that shows how language censures and as well as its ability to promote (liberate) chosen behaviour. Apart from the development of a more preferred sense of self, an interesting outcome from using this approach has also been the unique way restraint works within the school.

scholarly journals A model tool for assessing real-time mixing of mineral and anthropogenic pollutants in East Asia: a case study of April 2005

2008 ◽  
Vol 8 (13) ◽  
pp. 3603-3622 ◽  
Author(s):  
F. Lasserre ◽  
G. Cautenet ◽  
C. Bouet ◽  
X. Dong ◽  
Y. J. Kim ◽  
...  
Keyword(s):  
East Asia ◽  
Real Time ◽  
Anthropogenic Pollution ◽  
Atmospheric Modeling ◽  
Time Step ◽  
Anthropogenic Pollutants ◽  
Vertical Distributions ◽  
Dust Events ◽  
Horizontal And Vertical Distributions

Abstract. In order to assess the complex mixing of atmospheric anthropogenic and natural pollutants over the East Asian region, we present a modelling tool which takes into account the main aerosols which are to be found simultaneously over China, Korea and Japan during springtime. Using the mesoscale RAMS (Regional Atmospheric Modeling System) tool, we present a simulation of natural (desert) dust events along with some of the most critical anthropogenic pollutants over East Asia, sulphur elements (SO2 and SO2-4) and Black Carbon (BC). As regards a one-week case study of dust events which occurred during late April 2005 over an area extending from the Gobi deserts to the Japan surroundings, we satisfactorily model the behaviours of the different aerosol plumes. We focus on possible dust mixing with the anthropogenic pollutants from megacities. For both natural and anthropogenic pollution, the model results are in fairly good agreement with the horizontal and vertical distributions of concentrations as measured by in situ LIDAR, and as observed in remote data, PM10 data and literature. In particular, we show that a simplified chemistry approach of this complex issue is sufficient to model this event, with a real-time step of 3 h. The model reproduces the main patterns and orders of magnitude for Aerosol Optical Thickness (AOT) and species contributions (via the Angström Exponent) when compared with the AErosol RObotic NETwork (AERONET) data.

scholarly journals Scale model for the confluent area of debris flow and main river: a case study of the Wenjia Gully

2013 ◽  
Vol 13 (12) ◽  
pp. 3083-3093 ◽  
Author(s):  
J. Zhang ◽  
Z. X. Guo ◽  
S. Y. Cao ◽  
V. P. Singh
Keyword(s):  
Debris Flow ◽  
Viscosity Coefficient ◽  
Economic Loss ◽  
Scale Model ◽  
River Bed ◽  
Main River ◽  
Water Conveyance ◽  
The One ◽  
Similarity Laws

Abstract. When debris flow discharges into the main river, the deposition of debris raises the river bed, occupies the path of water conveyance and damages or even destroys buildings, resulting in considerable economic loss and possibly fatalities. Mathematical models are normally employed to compute debris flow. However, most of these models employ empirical formulae and coefficients and their results are seldom reliable. On the other hand, scale model tests associated with debris flow have seldom been conducted due to the lack of corresponding similarity laws and the difficulty of achieving the grain diameter scale. Focusing on pseudo-one-phase flow, this paper discusses the laws of similarity for the confluence of debris flow and main river and conducts a case study of the debris flow that occurred on 13 August 2010, in the Wenjia Gully, China. After satisfying the roughness scale, the kinematic viscosity coefficient scale, and the momentum ratio scale, it was found that the deposition terrain in the model test is consistent with the one in the prototype.

Performance Specifications for Real-Time Hybrid Testing of 1:50-Scale Floating Wind Turbine Models

2014 ◽  
Author(s):  
Matthew Hall ◽  
Javier Moreno ◽  
Krish Thiagarajan
Keyword(s):  
Wind Turbine ◽  
Real Time ◽  
Sensitivity Study ◽  
Scale Model ◽  
Testing System ◽  
Floating Platform ◽  
Hybrid Testing ◽  
Actuation Mechanism ◽  
Floating Wind Turbine ◽  
Performance Specifications

This paper presents performance requirements for a real-time hybrid testing system to be suitable for scale-model floating wind turbine experiments. In the wave basin, real-time hybrid testing could be used to replace the model wind turbine with an actuation mechanism, driven by a wind turbine simulation running in parallel with, and reacting to, the experiment. The actuation mechanism, attached to the floating platform, would provide the full range of forces normally provided by the model wind turbine. This arrangement could resolve scaling incompatibilities that currently challenge scale-model floating wind turbine experiments. In this paper, published experimental results and a collection of full-scale simulations are used to determine what performance specifications such a system would need to meet. First, an analysis of full-scale numerical simulations and published 1:50-scale experimental results is presented. This analysis indicates the required operating envelope of the actuation system in terms of displacements, velocities, accelerations, and forces. Next, a sensitivity study using a customization of the floating wind turbine simulator FAST is described. Errors in the coupling between the wind turbine and the floating platform are used to represent the various inaccuracies and delays that could be introduced by a real-time hybrid testing system. Results of this sensitivity study indicate the requirements — in terms of motion-tracking accuracy, force actuation accuracy, and system latency — for maintaining an acceptable level of accuracy in 1:50-scale floating wind turbine experiments using real-time hybrid testing.

The Influence of Qing Dynasty Editorial Work on the Modern Interpretation of Mathematical Sources: The Case of Li Rui's Edition of Li Ye's Mathematical Treatises

2014 ◽  
Vol 27 (3) ◽  
pp. 385-422 ◽  
Author(s):  
Charlotte-V. Pollet
Keyword(s):  
Qing Dynasty ◽  
Song Dynasty ◽  
Chinese Origin ◽  
Private Collection ◽  
Editorial Work ◽  
Talented Mathematician ◽  
Set Up ◽  
The One ◽  
Second Procedure

ArgumentRecent studies in Sinology have shown that Qing dynasty editors acted as philologists. This paper argues that the identification of their philological methods and editorial choices suggests that their choices were not totally neutral and may have significantly shaped the way modern historians interpreted specific works edited by mathematicians of that dynasty. A case study of the re-edition in 1798 of a Song dynasty treatise, theYigu yanduan(1259), by a Qing dynasty mathematician will illustrate this point. At the end of the eighteenth century, Li Rui (1773–1817) was asked to prepare an edition of the mathematical works written by Li Ye (1192–1279) for a private collection. Li Rui was a talented mathematician, but he was also a meticulous editor and trained philologist. He adopted his editorial model from the preparation of the imperial encyclopaedia, theSiku quanshu, but Li Rui also made some corrections to the text in an effort to restore an older version of Li Ye's treatises that had been lost. Convinced of the Chinese origin of algebra, Li Rui used philological techniques to recover the lost materials and to restore the roots of “Chinese mathematics.” TheYigu yanduancontains two algebraic procedures to set up quadratic equations, one from the procedure ofCelestial Source(tian yuan shu) and the other from theSection of Pieces[of Areas] (tiao duan). Curiously, the second procedure has not yet attracted the attention of scholars so far, although Li Rui's edition is the one typically used by twentieth-century historians of mathematics. Today, theCelestial Sourcecharacterizes “Chinese algebra.” However, the specific concerns of Li Rui about the procedure ofCelestial Source, combined with his editorial methods, contributed to this perspective.

scholarly journals Ramping of Demand Response Event with Deploying Distinct Programs by an Aggregator

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1389 ◽  
Author(s):  
Omid Abrishambaf ◽  
Pedro Faria ◽  
Zita Vale
Keyword(s):  
Real Time ◽  
Demand Response ◽  
Small Time ◽  
Time Step ◽  
Strategic Plans ◽  
Time Simulation ◽  
Demand Reduction ◽  
Resistive Loads ◽  
Demand Response Programs

System operators have moved towards the integration of renewable resources. However, these resources make network management unstable as they have variations in produced energy. Thus, some strategic plans, like demand response programs, are required to overcome these concerns. This paper develops an aggregator model with a precise vision of the demand response timeline. The model at first discusses the role of an aggregator, and thereafter is presented an innovative approach to how the aggregator deals with short and real-time demand response programs. A case study is developed for the model using real-time simulator and laboratory resources to survey the performance of the model under practical challenges. The real-time simulation uses an OP5600 machine that controls six laboratory resistive loads. Furthermore, the actual consumption profiles are adapted from the loads with a small-time step to precisely survey the behavior of each load. Also, remuneration costs of the event during the case study have been calculated and compared using both actual and simulated demand reduction profiles in the periods prior to event, such as the ramp period.

Analysis of delay compensation in real-time dynamic hybrid testing with large integration time-step

2014 ◽  
Vol 14 (6) ◽  
pp. 1269-1289 ◽  
Author(s):  
Fei Zhu ◽  
Jin-Ting Wang ◽  
Feng Jin ◽  
Yao Gui ◽  
Meng-Xia Zhou
Keyword(s):  
Real Time ◽  
Integration Time ◽  
Delay Compensation ◽  
Time Step ◽  
Hybrid Testing ◽  
Time Dynamic ◽  
Dynamic Hybrid

scholarly journals The management of challenges related to the innovation process: a multi-case study in industries of the cosmetic sector

2020 ◽  
Vol 13 ◽  
pp. 1289-1313
Author(s):  
Inayara Valéria Defreitas Pedroso Gonzalez
Keyword(s):  
Qualitative Research ◽  
Innovation Process ◽  
Structured Interview ◽  
Shared Vision ◽  
Strategic Learning ◽  
Learning To Learn ◽  
Managerial Practices ◽  
Main Challenge ◽  
The One

Purpose – The objective was to reveal reflections on how the managers of industrial cosmetic companies deal with the challenges related to the innovation process.Design/methodology/approach – Exploratory qualitative research. The present research uses a combination of methods: theoretical-conceptual, bibliographical survey and the multi-case study, by means of the following procedures: semi-structured interview, observation route and document analysis.Findings – I concluded that the main challenges faced by the management of the innovation process in the small business are related to the non-development of a culture focused on innovation and not planning the capacity to decentralize. In the case of the medium sized company, the main challenge related to the innovation process is to manage, simultaneously, the growth of the company on the one hand, and the managerial practices aimed at the use of the knowledge of its team, on the other, in the process of innovation. In the case of the large company, I concluded that the challenges of maintaining the integration of the innovation process and, at the same time, the flexibility to transform the way things are done, are well orchestrated by management because there is constant discussion and shared vision, in a spirit of trust and teamwork.Research limitations/implications – The data cannot be generalized because it is a multi-case study.Practical implications – As soon as the challenges were identified, the assumption was confirmed that the achievement of innovation implies knowing how to integrate resources and capacities, manage periods of instability or irregularity and regularity, based on a culture focused on strategic learning, learning to learn and, systemic learning.Originality/value - This exploratory qualitative research contributes with evidences and analyzes on the management of the innovation process in three companies of different sizes, in which are revealed the managerial actions in relation to the innovation requirements that have been explored from the theoretical bases that support the integration of the learning organizational and management of innovation, and the reflections on how manifest the management of the challenges faced in each company.

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