Considering the Effect of Land-Based Biomass on Dune Erosion Volumes in Large-Scale Numerical Modeling

This paper presents and validates a novel root model which accounts for the effect of belowground biomass on dune erosion volumes in XBeach, based on a small-scale wave flume experiment that was translated to a larger scale. A 1D-XBeach model was calibrated by using control runs considering a dune without vegetation. Despite calibration, a general model–data mismatch was observed in terms of overestimated erosion volumes around the waterline. Furthermore, the prediction of overwash had to be induced by increasing the maximum nearshore wave height within the XBeach simulation. Subsequently, applying the root model resulted in a good agreement with the belowground biomass cases, and the consideration of spatially varying rooting depths further improved the results. Predictions of the root model while using locally increased friction coefficients were in line with the aboveground and belowground biomass cases. However, the effect of the root model on the erosion predictions varied among the hydrodynamic conditions, so further improvements are required. Therefore, future research should focus on quantifying the effects of land-based biomass and individual plant characteristics, such as root density, on dune erodibility at large scales, along with their influences on the temporal evolution of dune scarping and avalanching.

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Large Scale Experimental Study of the Scour Protection Damage Around a Monopile Foundation Under Combined Wave and Current Conditions

Journal of Marine Science and Engineering ◽

10.3390/jmse8060417 ◽

2020 ◽

Vol 8 (6) ◽

pp. 417 ◽

Cited By ~ 1

Author(s):

Minghao Wu ◽

Leen De Vos ◽

Carlos Emilio Arboleda Chavez ◽

Vasiliki Stratigaki ◽

Tiago Fazeres-Ferradosa ◽

...

Keyword(s):

Large Scale ◽

Three Dimensional ◽

Static Stability ◽

Future Research ◽

Small Scale ◽

Flume Experiments ◽

Wave Flume ◽

Scale Models ◽

Damage Data ◽

Scour Protection

This paper presents a series of large-scale wave flume experiments on the scour protection damage around a monopile under combined waves and current conditions with model scales of 1:16.67 and 1:8.33. The main objective is to compare the damage data obtained from these large-scale models with existing monopile scour protection design approaches, which were proposed based on small scale wave flume experiments, and to study the applicability of the existing approaches. The static stability (onset of motion and bed shear stress) and the dynamic stability (three-dimensional damage numbers) of the scour protection are investigated. Both results show that the existing design approaches can be conservative when applied to large scale models, which highlights the need of further investigations on scale and model effects. In addition, this paper also analyses the scour protection damage depth. It is observed that damage depths of the scour protection layer under low Keulegan–Carpenter number (KC) conditions are smaller than predictions. The study provides valuable large scale experimental data for future research on the monopile scour protection design.

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Agile Transformation at Scale: A Tertiary Study

10.1007/978-3-030-88583-0_1 ◽

2021 ◽

pp. 3-11

Author(s):

Suddhasvatta Das ◽

Kevin Gary

Keyword(s):

Large Scale ◽

Software Industry ◽

Future Research ◽

Small Scale ◽

Agile Processes ◽

Current State ◽

Research Findings ◽

State Of Research ◽

Agile Software ◽

Tertiary Study

AbstractDue to the fast-paced nature of the software industry and the success of small agile projects, researchers and practitioners are interested in scaling agile processes to larger projects. Agile software development (ASD) has been growing in popularity for over two decades. With the success of small-scale agile transformation, organizations started to focus on scaling agile. There is a scarcity of literature in this field making it harder to find plausible evidence to identify the science behind large scale agile transformation. The objective of this paper is to present a better understanding of the current state of research in the field of scaled agile transformation and explore research gaps. This tertiary study identifies seven relevant peer reviewed studies and reports research findings and future research avenues.

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Galactic Dynamos — a Challenge for Observers

Symposium - International Astronomical Union ◽

10.1017/s0074180900174297 ◽

1993 ◽

Vol 157 ◽

pp. 283-297

Author(s):

Rainer Beck

Keyword(s):

Large Scale ◽

General Distribution ◽

Future Research ◽

Small Scale ◽

Dynamo Theory ◽

Galactic Winds ◽

Scale Field ◽

Field Lines ◽

Galactic Dynamos ◽

The Magnetic Field

Results of linear αΩ-dynamo models are confronted with radio polarization observations of spiral galaxies. The general distribution of polarized emission and the magnetic field pitch angle can be described with sufficient accuracy. The occurrance of systematic large-scale variations in Faraday rotation (RM) is the strongest argument in favour of dynamo theory. However, the predominance of axisymmetric SO modes could not be confirmed by observations; S1 modes are about equally frequent. The azimuthal variations of field pitch angles and, in two cases, the phases of the RM variations are inconsistent with a classical αΩ-dynamo. Locally deviating RM values indicate field lines bending out of the plane. There is increasing evidence that galactic fields cannot be described by simple dynamo modes. This calls for more realistic dynamo models, taking into account non-axisymmetric velocity fields and galactic winds.Interpretation of radio observations is difficult because Faraday depolarization can seriously affect the data. Observations of small-scale field structures are summarized which show the path for future research. Instrumental needs for such investigations are discussed.

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Disaster management in industrial areas: Perspectives, challenges and future research

Journal of Industrial Engineering and Management ◽

10.3926/jiem.2663 ◽

2019 ◽

Vol 12 (1) ◽

pp. 133 ◽

Cited By ~ 2

Author(s):

Yousif A. M. A. Rebeeh ◽

Shaligram Pokharel ◽

Galal M.M. Abdella ◽

Abdelmagid S. Hammuda

Keyword(s):

Content Analysis ◽

Disaster Management ◽

Large Scale ◽

Industrial Area ◽

Theory And Practice ◽

Future Research ◽

Individual Plant ◽

Industrial Facilities ◽

Industrial Areas ◽

Industrial Cities

Purpose: In most countries, development, growth, and sustenance of industrial facilities are given utmost importance due to the influence in the socio-economic development of the country. Therefore, special economic zones, or industrial areas or industrial cities are developed in order to provide the required services for the sustained operation of such facilities. Such facilities not only provide prolonged economic support to the country but it also helps in the societal aspects as well by providing livelihood to thousands of people. Therefore, any disaster in any of the facilities in the industrial area will have a significant impact on the population, facilities, the economy, and threatens the sustainability of the operations. This paper provides review of such literature that focus on theory and practice of disaster management in industrial cities.Design/methodology/approach: In the paper, content analysis method in order to elicit the insights of the literature available.Findings: It is found that the research is done in all phases of disaster management, namely, preventive phase, reactive phase and corrective phase. The research in each of these areas are focused on four main aspects, which are facilities, resources, support systems and modeling. Nevertheless, the research in the industrial cities is insignificant. Moreover, the modeling part does not explicitly consider the nature of industrial cities, where many of the chemical and chemical processing can be highly flammable thus creating a very large disaster impact. Some research is focused at an individual plant and scaled up to the industrial cities. The modeling part is weak in terms of comprehensively analyzing and assisting disaster management in the industrial cities.Originality/value: The comprehensive review using content analysis on disaster management is presented here. The review helps the researchers to understand the gap in the literature in order to extend further research for disaster management in large scale industrial cities.

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The impact of inhomogeneous subgrid clumping on cosmic reionization

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz2986 ◽

2019 ◽

Vol 491 (2) ◽

pp. 1600-1621

Author(s):

Yi Mao ◽

Jun Koda ◽

Paul R Shapiro ◽

Ilian T Iliev ◽

Garrelt Mellema ◽

...

Keyword(s):

High Resolution ◽

Large Scale ◽

Power Spectra ◽

Coarse Grained ◽

Small Scale ◽

Sources And Sinks ◽

Coarse Grained Simulations ◽

Cent Error ◽

Spatially Varying ◽

The Impact

ABSTRACT Cosmic reionization was driven by the imbalance between early sources and sinks of ionizing radiation, both of which were dominated by small-scale structure and are thus usually treated in cosmological reionization simulations by subgrid modelling. The recombination rate of intergalactic hydrogen is customarily boosted by a subgrid clumping factor, 〈n2〉/〈n〉2, which corrects for unresolved fluctuations in gas density n on scales below the grid-spacing of coarse-grained simulations. We investigate in detail the impact of this inhomogeneous subgrid clumping on reionization and its observables, as follows: (1) Previous attempts generally underestimated the clumping factor because of insufficient mass resolution. We perform a high-resolution N-body simulation that resolves haloes down to the pre-reionization Jeans mass to derive the time-dependent, spatially varying local clumping factor and a fitting formula for its correlation with local overdensity. (2) We then perform a large-scale N-body and radiative transfer simulation that accounts for this inhomogeneous subgrid clumping by applying this clumping factor-overdensity correlation. Boosting recombination significantly slows the expansion of ionized regions, which delays completion of reionization and suppresses 21 cm power spectra on large scales in the later stages of reionization. (3) We also consider a simplified prescription in which the globally averaged, time-evolving clumping factor from the same high-resolution N-body simulation is applied uniformly to all cells in the reionization simulation, instead. Observables computed with this model agree fairly well with those from the inhomogeneous clumping model, e.g. predicting 21 cm power spectra to within 20 per cent error, suggesting it may be a useful approximation.

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Scaling the INGO: What the Development and Expansion of Canadian INGOs Tells Us

Social Sciences ◽

10.3390/socsci9080140 ◽

2020 ◽

Vol 9 (8) ◽

pp. 140

Author(s):

Logan Cochrane ◽

John-Michael Davis

Keyword(s):

Large Scale ◽

Scale Up ◽

Critical Factor ◽

Individual Case ◽

Government Funding ◽

Future Research ◽

Small Scale ◽

Non Governmental Organizations ◽

Original Dataset ◽

Organizational Age

The literature on international non-governmental organizations (INGOs) has focused primarily on large INGOs, which capture the majority of total INGO spending but represent a small number of total INGOs. Over the past two decades, the number of INGOs has more than tripled throughout the global North, which has ushered in a decentralization of the sector as an emerging class of small- and medium-sized INGOs increasingly share the same space once occupied solely by large INGOs. This study focuses on these INGOs in transition to explore how they differ from large INGOs that receive significant government funding and their pathways to scale. Using an original dataset of 1371 Canadian INGOs, we explored comparative differences related to funding sources, overhead, organizational age, country coverage, staff, and religion between the transitioning and small-scale INGOs. Our results identified several general insights for how INGOs transition: (1) Large INGOs are less likely to articulate a religious motivation, which may impede government funding; (2) INGOs are more likely to be headquartered in Ontario, which is closer to federal government offices; (3) low overhead expenditures inhibit small-scale INGOs from transitioning to medium- and large-scale INGOs; (4) organizational age plays a critical factor to scale-up as INGOs increase their experience and expertise; (5) generous compensation to attract talented staff offers an under-valued pathway to scale. Finally, our results demonstrate the diversity among INGOs in Canada and problematizes singular scale-up pathways, while underscoring the necessity of future research to explore scaling strategies through individual case studies.

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Gas transfer under breaking waves: experiments and an improved vorticity-based model

Annales Geophysicae ◽

10.5194/angeo-26-2131-2008 ◽

2008 ◽

Vol 26 (8) ◽

pp. 2131-2142 ◽

Cited By ~ 1

Author(s):

V. K. Tsoukala ◽

C. I. Moutzouris

Keyword(s):

Experimental Data ◽

Oxygen Transfer ◽

Large Scale ◽

Breaking Waves ◽

Small Scale ◽

Gas Transfer ◽

Transfer Coefficients ◽

Wave Flume ◽

Proposed Model ◽

Sloping Beach

Abstract. In the present paper a modified vorticity-based model for gas transfer under breaking waves in the absence of significant wind forcing is presented. A theoretically valid and practically applicable mathematical expression is suggested for the assessment of the oxygen transfer coefficient in the area of wave-breaking. The proposed model is based on the theory of surface renewal that expresses the oxygen transfer coefficient as a function of both the wave vorticity and the Reynolds wave number for breaking waves. Experimental data were collected in wave flumes of various scales: a) small-scale experiments were carried out using both a sloping beach and a rubble-mound breakwater in the wave flume of the Laboratory of Harbor Works, NTUA, Greece; b) large-scale experiments were carried out with a sloping beach in the wind-wave flume of Delft Hydraulics, the Netherlands, and with a three-layer rubble mound breakwater in the Schneideberg Wave Flume of the Franzius Institute, University of Hannover, Germany. The experimental data acquired from both the small- and large-scale experiments were in good agreement with the proposed model. Although the apparent transfer coefficients from the large-scale experiments were lower than those determined from the small-scale experiments, the actual oxygen transfer coefficients, as calculated using a discretized form of the transport equation, are in the same order of magnitude for both the small- and large-scale experiments. The validity of the proposed model is compared to experimental results from other researchers. Although the results are encouraging, additional research is needed, to incorporate the influence of bubble mediated gas exchange, before these results are used for an environmental friendly design of harbor works, or for projects involving waste disposal at sea.

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Small and Large Scale Experimental Investigations of Wave Loads on a Slender Pile Within Closely Spaced Neighbouring Piles

Volume 1A: Offshore Technology ◽

10.1115/omae2014-23110 ◽

2014 ◽

Cited By ~ 1

Author(s):

Lisham Bonakdar ◽

Hocine Oumeraci

Keyword(s):

Laboratory Tests ◽

Large Scale ◽

Model Tests ◽

Scale Model ◽

Research Centre ◽

Experimental Investigations ◽

Small Scale ◽

Wave Loads ◽

Large Wave ◽

Wave Flume

Wave loads on a slender pile within a group of piles are studied by means of (i) large-scale laboratory tests carried out in the Large Wave Flume (GWK) of the Coastal Research Centre (FZK) in Hannover, and (ii) small scale experiments performed in 2 m-wide wave flume of Leichtweiss-Institute for Hydraulic Engineering and Water Resources (LWI), in Braunschweig, Germany. The small scale model tests (LWI) were scaled down (1:6.5) by Froude law from the large scale model tests (GWK). Scale and model effects are examined by comparing the results of small and large scale laboratory tests.

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Automatic sleep stage classification with deep residual networks in a mixed-cohort setting

SLEEP ◽

10.1093/sleep/zsaa161 ◽

2020 ◽

Author(s):

Alexander Neergaard Olesen ◽

Poul Jørgen Jennum ◽

Emmanuel Mignot ◽

Helge Bjarup Dissing Sorensen

Keyword(s):

Neural Network ◽

Large Scale ◽

Deep Neural Network ◽

Sleep Stage ◽

Scoring Systems ◽

Training Data ◽

Future Research ◽

Small Scale ◽

Sleep Stage Scoring ◽

Single Cohort

Abstract Study Objectives Sleep stage scoring is performed manually by sleep experts and is prone to subjective interpretation of scoring rules with low intra- and interscorer reliability. Many automatic systems rely on few small-scale databases for developing models, and generalizability to new datasets is thus unknown. We investigated a novel deep neural network to assess the generalizability of several large-scale cohorts. Methods A deep neural network model was developed using 15,684 polysomnography studies from five different cohorts. We applied four different scenarios: (1) impact of varying timescales in the model; (2) performance of a single cohort on other cohorts of smaller, greater, or equal size relative to the performance of other cohorts on a single cohort; (3) varying the fraction of mixed-cohort training data compared with using single-origin data; and (4) comparing models trained on combinations of data from 2, 3, and 4 cohorts. Results Overall classification accuracy improved with increasing fractions of training data (0.25%: 0.782 ± 0.097, 95% CI [0.777–0.787]; 100%: 0.869 ± 0.064, 95% CI [0.864–0.872]), and with increasing number of data sources (2: 0.788 ± 0.102, 95% CI [0.787–0.790]; 3: 0.808 ± 0.092, 95% CI [0.807–0.810]; 4: 0.821 ± 0.085, 95% CI [0.819–0.823]). Different cohorts show varying levels of generalization to other cohorts. Conclusions Automatic sleep stage scoring systems based on deep learning algorithms should consider as much data as possible from as many sources available to ensure proper generalization. Public datasets for benchmarking should be made available for future research.

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Towards Bio-Hybrid Energy Harvesting in the Real-World: Pushing the Boundaries of Technologies and Strategies Using Bio-Electrochemical and Bio-Mechanical Processes

Applied Sciences ◽

10.3390/app11052220 ◽

2021 ◽

Vol 11 (5) ◽

pp. 2220

Author(s):

Abanti Shama Afroz ◽

Donato Romano ◽

Francesco Inglese ◽

Cesare Stefanini

Keyword(s):

Fuel Cells ◽

Energy Harvesting ◽

Microbial Fuel Cells ◽

Large Scale ◽

Green Energy ◽

Future Research ◽

Small Scale ◽

Power Sources ◽

Energy Harvesters ◽

Living Organisms

Sustainable, green energy harvesting has gained a considerable amount of attention over the last few decades and within its vast field of resources, bio-energy harvesters have become promising. These bio-energy harvesters appear in a wide variety and function either by directly generating energy with mechanisms similar to living organisms or indirectly by extracting energy from living organisms. Presently this new generation of energy harvesters is fueling various low-power electronic devices while being extensively researched for large-scale applications. In this review we concentrate on recent progresses of the three promising bio-energy harvesters: microbial fuel cells, enzyme-based fuel cells and biomechanical energy harvesters. All three of these technologies are already extensively being used in small-scale applications. While microbial fuel cells hold immense potential in industrial-scale energy production, both enzyme-based fuel cells and biomechanical energy harvesters show promises of becoming independent and natural power sources for wearable and implantable devices for many living organisms including humans. Herein, we summarize the basic principles of these bio-energy harvesting technologies, outline their recent advancements and estimate the near future research trends.

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