scholarly journals CHARACTERISATION OF BREAKING WAVES ON THE EDDYSTONE LIGHTHOUSE: A LABORATORY INVESTIGATION ON WAVE PRESSURE

Author(s):  
Davide Banfi ◽  
Alison Raby ◽  
David Simmonds

Commonly, rock lighthouses are erected on the top of steep reefs and in limited water depths. The effect of these environmental conditions on wave loading requires deeper understanding. This paper investigates wave loading at small scale for a particular case study: the Eddystone lighthouse (UK). Load characteristics due to breaking waves are obtained by the use of pressure transducers and the test program is designed to generate a comprehensive data set covering a broader range of wave conditions. Although the magnitude of wave pressures is rather random from wave to wave of the same train of regular waves, the pressure impulsivity tends to decrease with increasing relative breaking distance. Four breaker types are described and particular attention is given to time histories of the line of action of horizontal force and vertical spatial distributions. Estimation of overall forces, obtained by pressure integration, indicates that the wave loading is strongly affected by the limited water depth condition. In fact, only small plunging waves are able to break at the structure; thus, they cause small forces despite the small breaking distances. Finally, the occurrence of the breakers is investigated on a dimensionless plane given by the combination of the Iribarren number and momentum flux of Hughes.

Author(s):  
Darshana T. Dassanayake ◽  
Alessandro Antonini ◽  
Alison Raby

Abstract Estimation of impulsive wave loading on a cylinder upon a shoal, such as an offshore rock lighthouse constructed on a partially emerged offshore rock with a steep foreshore, poses a unique challenge to marine structural engineers. Large and small scale experimental investigations are the most feasible methods to study this phenomena. However, any experimental investigation with impulsive loading faces challenges in the data analysis, when it is necessary to separate the total impact forces from the force response time series, and to separate the impulsive and quasi-static force components of the total force measurements. This paper is an attempt to re-visit several data analysis techniques with a unique experimental data set to study the advantages and limitations of those techniques, and also to learn how different techniques can be combined into a data analysis methodology to harness maximum information.


2010 ◽  
Vol 6 (S274) ◽  
pp. 140-142
Author(s):  
S. L. Guglielmino ◽  
V. Martínez Pillet ◽  
J. C. del Toro Iniesta ◽  
L. R. Bellot Rubio ◽  
F. Zuccarello ◽  
...  

AbstractThanks to the unprecedented combination of high spatial resolution (0″.2) and high temporal cadence (33 s) spectropolarimetric measurements, the IMaX magnetograph aboard the Sunrise balloon-borne telescope is revealing new insights about the plasma dynamics of the all-pervasive small-scale flux concentrations in the quiet Sun. We present the result of a case study concerning the appearance of a bipole, with a size of about 4″ and a flux content of 5 × 1017 Mx, with strong signal of horizontal fields during the emergence. We analyze the data set using the SIR inversion code and obtain indications about the three-dimensional shape of the bipole and its evolution with time.


Author(s):  
Michael W. Pratt ◽  
M. Kyle Matsuba

Chapter 7 begins with an overview of Erikson’s ideas about intimacy and its place in the life cycle, followed by a summary of Bowlby and Ainsworth’s attachment theory framework and its relation to family development. The authors review existing longitudinal research on the development of family relationships in adolescence and emerging adulthood, focusing on evidence with regard to links to McAdams and Pals’ personality model. They discuss the evidence, both questionnaire and narrative, from the Futures Study data set on family relationships, including emerging adults’ relations with parents and, separately, with grandparents, as well as their anticipations of their own parenthood. As a way of illustrating the key personality concepts from this family chapter, the authors end with a case study of Jane Fonda in youth and her father, Henry Fonda, to illustrate these issues through the lives of a 20th-century Hollywood dynasty of actors.


Author(s):  
Michael W. Pratt ◽  
M. Kyle Matsuba

Chapter 6 reviews research on the topic of vocational/occupational development in relation to the McAdams and Pals tripartite personality framework of traits, goals, and life stories. Distinctions between types of motivations for the work role (as a job, career, or calling) are particularly highlighted. The authors then turn to research from the Futures Study on work motivations and their links to personality traits, identity, generativity, and the life story, drawing on analyses and quotes from the data set. To illustrate the key concepts from this vocation chapter, the authors end with a case study on Charles Darwin’s pivotal turning point, his round-the-world voyage as naturalist for the HMS Beagle. Darwin was an emerging adult in his 20s at the time, and we highlight the role of this journey as a turning point in his adult vocational development.


2003 ◽  
Vol 42 (05) ◽  
pp. 564-571 ◽  
Author(s):  
M. Schumacher ◽  
E. Graf ◽  
T. Gerds

Summary Objectives: A lack of generally applicable tools for the assessment of predictions for survival data has to be recognized. Prediction error curves based on the Brier score that have been suggested as a sensible approach are illustrated by means of a case study. Methods: The concept of predictions made in terms of conditional survival probabilities given the patient’s covariates is introduced. Such predictions are derived from various statistical models for survival data including artificial neural networks. The idea of how the prediction error of a prognostic classification scheme can be followed over time is illustrated with the data of two studies on the prognosis of node positive breast cancer patients, one of them serving as an independent test data set. Results and Conclusions: The Brier score as a function of time is shown to be a valuable tool for assessing the predictive performance of prognostic classification schemes for survival data incorporating censored observations. Comparison with the prediction based on the pooled Kaplan Meier estimator yields a benchmark value for any classification scheme incorporating patient’s covariate measurements. The problem of an overoptimistic assessment of prediction error caused by data-driven modelling as it is, for example, done with artificial neural nets can be circumvented by an assessment in an independent test data set.


2021 ◽  
pp. 136700692110231
Author(s):  
Francesca Romana Moro

Aims and Objectives/Purpose/Research Questions: The Alorese in eastern Indonesia are an Austronesian community who have inhabited two Papuan-speaking islands for approximately 600 years. Their language presents a paradox: contact with the neighbouring Papuan languages has led to both complexification and simplification. This article argues that these opposite outcomes of contact result from two distinct scenarios, and formulates a hypothesis about a shift in multilingual patterns in Alorese history. Design/Methodology/Approach: To formulate a hypothesis about the discontinuity of multilingual patterns, this article first sketches the past and present multilingual patterns of the Alorese by modelling language contact outcomes in terms of bilingual optimisation strategies. This is followed by a comparison of the two scenarios to pinpoint similarities and differences. Data and Analysis: Previous research shows that two types of contact phenomena are attested in Alorese: (a) complexification arising from grammatical borrowings from Papuan languages, and (b) morphological simplification. The first change is associated with prolonged child bilingualism and is the result of Papuan-oriented bilingual strategies, while the latter change is associated with adult second language (L2) learning and is the result of universal communicative strategies. Findings/Conclusions Complexification and simplification are the results of two different layers of contact. Alorese was first used in small-scale bilingual communities, with widespread symmetric multilingualism. Later, multilingualism became more asymmetric, and the language started to undergo a simplification process due to the considerable number of L2 speakers. Originality: This article is innovative in providing a clear case study showing discontinuity of multilingual patterns, supported by linguistic and non-linguistic evidence. Significance/Implications: This article provides a plausible explanation for the apparent paradox found in Alorese, by showing that different outcomes of contact in the same language are due to different patterns of acquisition and socialisation. This discontinuity should be taken into account by models of language contact.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1862
Author(s):  
Alexandros-Georgios Chronis ◽  
Foivos Palaiogiannis ◽  
Iasonas Kouveliotis-Lysikatos ◽  
Panos Kotsampopoulos ◽  
Nikos Hatziargyriou

In this paper, we investigate the economic benefits of an energy community investing in small-scale photovoltaics (PVs) when local energy trading is operated amongst the community members. The motivation stems from the open research question on whether a community-operated local energy market can enhance the investment feasibility of behind-the-meter small-scale PVs installed by energy community members. Firstly, a review of the models, mechanisms and concepts required for framing the relevant concepts is conducted, while a clarification of nuances at important terms is attempted. Next, a tool for the investigation of the economic benefits of operating a local energy market in the context of an energy community is developed. We design the local energy market using state-of-the-art formulations, modified according to the requirements of the case study. The model is applied to an energy community that is currently under formation in a Greek municipality. From the various simulations that were conducted, a series of generalizable conclusions are extracted.


2021 ◽  
pp. 003452372198937
Author(s):  
Caroline Elbra-Ramsay

This paper reports the findings of a small-scale study seeking to investigate how student teachers, within a three-year undergraduate programme, understand feedback. Feedback has been central to debates and discussion in the assessment literature in recent years. Hence, in this paper, feedback is positioned within the often-contradictory discourses of assessment, including perspectives on student and teacher feedback. The study focused on two first year undergraduate student teachers at a small university in England and considered the relationships between their understanding of feedback as a student, their understanding of feedback as an emerging teacher, and the key influences shaping these understandings. A phenomenological case study methodology was employed with interviews as the prime method of data collection. Themes emerged as part of an Nvivo analysis, including emotional responses, relationships and dialogue, all of which appear to have impacted on the students’ conceptual understanding of feedback as indelibly shaped by its interpersonal and affective, rather than purely cognitive or ideational, dimensions. The paper therefore seeks to contribute to the wider feedback discourse by offering an analysis of empirical data. Although situated within English teacher education, there are tentative conclusions that are applicable to international teacher education and as well as higher education more generally.


Sign in / Sign up

Export Citation Format

Share Document