scholarly journals Multidimensional Skills, Sorting, and Human Capital Accumulation

2020 ◽  
Vol 110 (8) ◽  
pp. 2328-2376 ◽  
Author(s):  
Jeremy Lise ◽  
Fabien Postel-Vinay
Keyword(s):  
Job Search ◽  
Capital Accumulation ◽  
Structural Model ◽  
Initial Conditions ◽  
Model Combining ◽  
Combining Data ◽  
Sources Of Variation ◽  
Skill Requirements ◽  
Skill Dimensions ◽  
Shed Light

We construct a structural model of on-the-job search in which workers differ in skills along several dimensions and sort themselves into jobs with heterogeneous skill requirements along those same dimensions. Skills are accumulated when used, and depreciate when not used. We estimate the model combining data from O*NET with the NLSY79. We use the model to shed light on the origins and costs of mismatch along heterogeneous skill dimensions. We highlight the deficiencies of relying on a unidimensional model of skill when decomposing the sources of variation in the value of lifetime output between initial conditions and career shocks. (JEL J24, J41, J64)

Kinematic characteristics of longitudinal double folding wings

2021 ◽  
pp. 1-25
Author(s):  
L. Tiegang ◽  
C. Guoguang ◽  
L. Shuai
Keyword(s):  
Angular Velocity ◽  
Structural Model ◽  
Initial Conditions ◽  
Aerodynamic Force ◽  
Model Simulation ◽  
Lagrange Equation ◽  
Grid Method ◽  
Weapon Systems ◽  
Folding Wing ◽  
Double Folding

ABSTRACT A folding wing is a tactical missile launching device that needs to be miniaturised to facilitate storage, transportation, and launching; save missile and transportation space; and improve the combat capability of weapon systems. This study investigates the aeroelastic characteristics of the secondary longitudinal folding wing during the unfolding process. First, the Lagrange equation is used to establish the structural dynamics model of the folding wing, the kinematics characteristics during the deformation process are analysed, and the unfolding movement of the folding wing is obtained using the dynamic equations in the process. Then, the generalised unsteady aerodynamic force is calculated using the dipole grid method, and the multi-body dynamics equation of the folding wing is obtained. The initial angular velocity required for the deployment of the folding wing is analysed through structural model simulation, and the influence of the initial angular velocity on the opening process is studied. Finally, aeroelastic flutter analysis is performed on the folding wing, and the physical model of the folding wing verified experimentally. Results show that the type of aeroelastic response is sensitive to the initial conditions and the way the folding wing opens.

SMEs strategic networks and innovative performance: a relational design and methodology for knowledge sharing

2020 ◽  
Vol 24 (6) ◽  
pp. 1369-1392 ◽  
Author(s):  
Elena-Mădălina Vătămănescu ◽  
Juan-Gabriel Cegarra-Navarro ◽  
Andreia Gabriela Andrei ◽  
Violeta-Mihaela Dincă ◽  
Vlad-Andrei Alexandru
Keyword(s):  
Knowledge Sharing ◽  
Structural Equation ◽  
Structural Model ◽  
Resource Scarcity ◽  
Content Type ◽  
Strategic Networks ◽  
Innovative Performance ◽  
Positive Effects ◽  
Model Combining ◽  
Fierce Competition

Purpose In the context of resource scarcity, the affiliation of small and medium-sized enterprises (SMEs) to strategic networks has emerged as a fruitful path towards knowledge sharing as a reaction to fierce competition and with a view to enhance their innovative performance. In this framework, this paper aims to investigate the influence exerted by a specific relational design (i.e. types of strategic networks) and methodology (i.e. channels and content) of knowledge sharing on SMEs innovative performance. Design/methodology/approach A questionnaire-based survey with 102 top managers of European SMEs in the industrial field was conducted from June to August 2019 and a partial least squares structural equation modelling technique was used. The database was initially filtered to ensure the adequacy of the sample and data was analysed using the statistics software package SmartPLS 3.0. Findings The results concluded that the structural model explains 38.5% of the variance in SMEs innovative performance, indicating the positive effects exerted by offline and online and by competitive knowledge sharing on the dependent variable. Research implications The study has both theoretical and practical implications in that it sets out a reference point for the key performance indicators for strategic networks structure, formation and development and, implicitly, for the selection of the most efficient relational design and methodology. Originality/value The pivotal originality elements reside in the advancement of a more comprehensive conceptual and structural model combining a two-fold operationalization of SMEs strategic networks (founded on business abilities or on the personality of the partner) and in the investigation of knowledge transfer processes at the inter-organizational levels within a context-centric approach.

scholarly journals A CLASSICAL MODEL OF EDUCATION, GROWTH, AND DISTRIBUTION

2018 ◽  
Vol 24 (5) ◽  
pp. 1186-1221
Author(s):  
Amitava Krishna Dutt ◽  
Roberto Veneziani
Keyword(s):  
Capital Accumulation ◽  
Classical Model ◽  
Human Capital Accumulation ◽  
Macroeconomic Model ◽  
Education Policies ◽  
Distributional Consequences ◽  
The Usa ◽  
Market Relations ◽  
Shed Light ◽  
Growth Distribution

We develop a classical macroeconomic model to examine the growth and distributional consequences of education. Contrary to the received wisdom, we show that human capital accumulation is not necessarily growth-inducing and inequality-reducing. Expansive education policies may foster growth and reduce earning inequalities between workers, but only by transferring income from workers to capitalists. Further, the overall effect of an increase in education depends on the actual characteristics of the educational system and on the nature of labor market relations. Although the primary aim of the paper is theoretical, we argue that the model identifies some causal mechanisms that can contribute to shed light on recent stylized facts on growth, distribution, and education for the USA.

scholarly journals Fiber tractography bundle segmentation depends on scanner effects, acquisition, diffusion sensitization, and bundle segmentation workflow

2021 ◽  
Author(s):  
Kurt Schilling ◽  
Chantal M.W. Tax ◽  
Francois Rheault ◽  
Colin B Hansen ◽  
Qi Yang ◽  
...  
Keyword(s):  
White Matter ◽  
Mean Diffusivity ◽  
B Value ◽  
Fiber Tractography ◽  
Acquisition Protocol ◽  
Segmentation Methods ◽  
Combining Data ◽  
Potential Sources ◽  
Sources Of Variation ◽  
The Brain

When investigating connectivity and microstructure of white matter pathways of the brain using diffusion tractography bundle segmentation, it is important to understand potential confounds and sources of variation in the process. While cross-scanner and cross-protocol effects on diffusion microstructure measures are well described (in particular fractional anisotropy and mean diffusivity), it is unknown how potential sources of variation effect bundle segmentation results, which features of the bundle are most affected, where variability occurs, nor how these sources of variation depend upon the method used to reconstruct and segment bundles. In this study, we investigate four potential sources of variation, or confounds, for bundle segmentation: variation (1) across scan repeats, (2) across scanners, (3) across acquisition protocol, and (4) across diffusion sensitization. We employ four different bundle segmentation workflows on two benchmark multi-subject cross-scanner and cross-protocol databases, and investigate reproducibility and biases in volume overlap, shape geometry features of fiber pathways, and microstructure features within the pathways. We find that the effects of acquisition protocol, in particular acquisition resolution, result in the lowest reproducibility of tractography and largest variation of features, followed by scanner-effects, and finally b-value effects which had similar reproducibility as scan-rescan variation. However, confounds varied both across pathways and across segmentation workflows, with some bundle segmentation workflows more (or less) robust to sources of variation. Despite variability, bundle dissection is consistently able to recover the same location of pathways in the deep white matter, with variation at the gray matter/ white matter interface. Next, we show that differences due to the choice of bundle segmentation workflows are larger than any other studied confound, with low-to-moderate overlap of the same intended pathway when segmented using different methods. Finally, quantifying microstructure features within a pathway, we show that tractography adds variability over-and-above that which exists due to noise, scanner effects, and acquisition effects. Overall, these confounds need to be considered when harmonizing diffusion datasets, interpreting or combining data across sites, and when attempting to understand the successes and limitations of different methodologies in the design and development of new tractography or bundle segmentation methods.

Beyond legacy: Backstage stigmatisation and ‘trickle-up’ politics of urban regeneration

2018 ◽  
Vol 66 (4) ◽  
pp. 919-934 ◽  
Author(s):  
Kirsteen Paton
Keyword(s):  
Capital Accumulation ◽  
Private Business ◽  
Private Finance ◽  
Business Interests ◽  
Neoliberal Governance ◽  
East End ◽  
The Individual ◽  
Commonwealth Games ◽  
Shed Light

This article explores how stigmatisation is intimately linked with neoliberal governance and capital accumulation in specific ways through processes around the Glasgow Commonwealth Games. It advances the author’s previous research exploring the effects of stigma on the East End community hosting the Games, by looking at some of the processes of power and profit which motivate stigmatising processes by ‘gazing up’, rather than ‘gazing down’. That is, looking at the role of the stigmatisers in this project and not the stigmatised. It draws loosely on Goffman’s concept of ‘backstage’ to shed light on those who produce and profit from these stigmatisation processes, including government bodies and actors and private business interests. Looking at some of the processes through which stigmatisation is profited from reveals not only forms of power vital to this process but that it is a key form of exploitation integral to capital accumulation. Under austerity, the political economy of the Games constitutes state support of private finance and a simultaneous withdrawal of social welfare support, which transfers the burden of debt from the state to the individual and wealth from public funds to private funds.

scholarly journals Research on Modeling and Analysis of Generative Conversational System Based on Optimal Joint Structural and Linguistic Model

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1675 ◽  
Author(s):  
Yingzhong Tian ◽  
Yafei Jia ◽  
Long Li ◽  
Zongnan Huang ◽  
Wenbin Wang
Keyword(s):  
Neural Network ◽  
Network Architecture ◽  
Structural Model ◽  
Modeling And Analysis ◽  
Response Diversity ◽  
Linguistic Model ◽  
Model Combining ◽  
System Method ◽  
Single Turn ◽  
Comparative Results

Generative conversational systems consisting of a neural network-based structural model and a linguistic model have always been considered to be an attractive area. However, conversational systems tend to generate single-turn responses with a lack of diversity and informativeness. For this reason, the conversational system method is further developed by modeling and analyzing the joint structural and linguistic model, as presented in the paper. Firstly, we establish a novel dual-encoder structural model based on the new Convolutional Neural Network architecture and strengthened attention with intention. It is able to effectively extract the features of variable-length sequences and then mine their deep semantic information. Secondly, a linguistic model combining the maximum mutual information with the foolish punishment mechanism is proposed. Thirdly, the conversational system for the joint structural and linguistic model is observed and discussed. Then, to validate the effectiveness of the proposed method, some different models are tested, evaluated and compared with respect to Response Coherence, Response Diversity, Length of Conversation and Human Evaluation. As these comparative results show, the proposed method is able to effectively improve the response quality of the generative conversational system.

scholarly journals The Cost of Job Loss

2020 ◽  
Vol 87 (4) ◽  
pp. 1757-1798 ◽  
Author(s):  
Kenneth Burdett ◽  
Carlos Carrillo-Tudela ◽  
Melvyn Coles
Keyword(s):  
Human Capital ◽  
Job Search ◽  
Capital Accumulation ◽  
Job Loss ◽  
Learning By Doing ◽  
Risk Averse ◽  
Wage Formation ◽  
Optimal Contracting ◽  
The Cost ◽  
German Data

Abstract This article identifies an equilibrium theory of wage formation and endogenous quit turnover in a labour market with on-the-job search, where risk averse workers accumulate human capital through learning-by-doing and lose skills while unemployed. Optimal contracting implies the wage paid increases with experience and tenure. Indirect inference using German data determines the deep parameters of the model. The estimated model not only reproduces the large and persistent fall in wages and earnings following job loss, a new structural decomposition finds foregone human capital accumulation (while unemployed) is the worker’s major cost of job loss.

scholarly journals Hydrodynamics of flagellated microswimmers near free-slip interfaces

2016 ◽  
Vol 789 ◽  
pp. 514-533 ◽  
Author(s):  
D. Pimponi ◽  
M. Chinappi ◽  
P. Gualtieri ◽  
C. M. Casciola
Keyword(s):  
Numerical Solutions ◽  
Stokes Equations ◽  
Slip Surface ◽  
Initial Conditions ◽  
Aerobic Bacteria ◽  
Slip Boundary ◽  
Experimental Findings ◽  
Micro Organisms ◽  
Air Interfaces ◽  
Shed Light

The hydrodynamics of a flagellated micro-organism is investigated when swimming close to a planar free-slip surface by means of numerical solutions of the Stokes equations obtained via a boundary element method. Depending on the initial conditions, the swimmer can either escape from the free-slip surface or collide with the boundary. Interestingly, the micro-organism does not exhibit a stable orbit. Independently of escape or attraction to the interface, close to a free-slip surface, the swimmer follows a counter-clockwise trajectory, in agreement with experimental findings (Di Leonardo et al., Phys. Rev. Lett., vol. 106 (3), 2011, 038101). The hydrodynamics is indeed modified by the free surface. In fact, when the same swimmer moves close to a no-slip wall, a set of initial conditions exists which result in stable orbits. Moreover, when moving close to a free-slip or a no-slip boundary, the swimmer assumes a different orientation with respect to its trajectory. Taken together, these results contribute to shed light on the hydrodynamical behaviour of micro-organisms close to liquid–air interfaces which are relevant for the formation of interfacial biofilms of aerobic bacteria.

Ensemble-Based Data Assimilation for Wind Forecasting – Application to Wind Farm

2020 ◽  
Author(s):  
Yang-Ming Fan
Keyword(s):  
Wind Speed ◽  
Natural Gas ◽  
Data Assimilation ◽  
Wind Energy ◽  
Wind Farm ◽  
Initial Conditions ◽  
Wind Farms ◽  
Weather Conditions ◽  
Energy Output ◽  
Combining Data

<p>The purpose of this study is to develop an ensemble-based data assimilation method to accurately predict wind speed in wind farm and provide it for the use of wind energy intelligent forecasting platform. As Taiwan government aimed to increase the share of renewable energy generation to 20% by 2025, among them, the uncertain wind energy output will cause electricity company has to reserve a considerable reserve capacity when dispatching power, and it is usually high cost natural gas power generation. In view of this, we will develop wind energy intelligent forecasting platform with an error of 10% within 72 hours and expect to save hundred millions of dollars of unnecessary natural gas generators investment. Once the wind energy can be predicted more accurately, the electricity company can fully utilize the robustness and economy of smart grid supply. Therefore, the mastery of the change of wind speed is one of the key factors that can reduce the minimum error of wind energy intelligent forecasting.</p><p>There are many uncertainties in the numerical meteorological models, including errors in the initial conditions or defects in the model, which may affect the accuracy of the prediction. Since the deterministic prediction cannot fully grasp the uncertainty in the prediction process, so it is difficult to obtain all possible wind field changes. The development of ensemble-based data assimilation prediction is to make up for the weakness of deterministic prediction. With the prediction of 20 wind fields as ensemble members, it is expected to include the uncertainty of prediction, quantify the uncertainty, and integrate the wind speed observations of wind farms as well to provide the optimal prediction of wind speed for the next 72 hours. The results show that the prediction error of wind speed within 72 hours is 6% under different weather conditions (excluding typhoons), which proves that the accuracy of wind speed prediction by combining data assimilation technology and ensemble approach is better.</p>

The thermal field across the Alpine orogen and its forelands and the relation to seismicity

2020 ◽  
Author(s):  
Cameron Spooner ◽  
Magdalena Scheck-Wenderoth ◽  
Mauro Cacace ◽  
Hans-Jürgen Götze ◽  
Elco Luijendijk
Keyword(s):  
Thermal Field ◽  
Structural Model ◽  
Seismogenic Zone ◽  
Thermally Activated ◽  
Brittle Ductile Transition ◽  
Region Temperature ◽  
Crustal Strength ◽  
Modelling Techniques ◽  
The Alps ◽  
Shed Light

<p>The Alpine orogen and its forelands comprise a multitude of crustal blocks from different tectonic providences and different physical properties. This implies that the thermal configuration of the lithosphere would also be expected to vary significantly throughout the region. Temperature is a key controlling factor for rock strength via thermally activated creep and it exerts a first order influence on the depth of the brittle-ductile transition zone, the lower bound to the seismogenic zone and the spatial distribution of seismicity. Here we present new results from INTEGRATE, a project in the DFG priority program Mountain Building in 4 Dimensions, as part of the AlpArray initiative, which aims to gain a better understanding of the structure, temperature and rheology of the crust and the uppermost mantle beneath the Alps and their forelands using multiple 3D modelling techniques. The overall goal is to test different hypotheses on the configuration of the lithosphere and its relation to the distribution of deformation and related seismicity in the Alpine region. We build on previous work of a 3D density differentiated structural model of the region that is consistent with deep seismic data and gravity, to calculate the 3D conductive steady state thermal field of the Alps and their forelands. The model is unique in using different thermal parameters for different tectonic domains and is validated with a dataset of wellbore temperatures from across the region. Comparing recorded seismicity to the calculated thermal field we find a systematic clustering of the deep seismic activity that correlates with different isotherms within individual crustal blocks, reflecting the presence of different dominant lithologies. These inferred lithologies in conjunction with the calculated temperatures and the previous 3D density-structural model of the region, can be used to shed light on the lateral changes in crustal strength within the Alps and their forelands, helping to explain the observed patterns of deformation.  </p>

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