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Achieving Transparency:A Metadata Perspective

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Data Intelligence 2023年第1期5卷 261-273页

作者： daniel Gillman US Bureau of Labor Statistics 2 Massachusetts Ave NE Washington District of Columbia 20212United States

Transparency is vital to realizing the promise of evidenced-based policymaking,where"evidence-based"means including information as to what data mean and why they should be ***,in turn,requires that enough of this information is *** speaking then,transparency is achieved when sufficient documentation is *** is situation specific,both for the provider and consumer of the *** ideas are presented in two recent Us commissioned reports:The Promise of Evidence-Based Policymaking and Transparency in Statistical Information for the National Center for Science and Engineering Statistics and All Federal Statistical *** are a more formalized kind of documentation,and in this paper,we provide and demonstrate necessary,sufficient,and general conditions for achieving transparency from the metadata perspective:conforming to a specification,providing quality metadata,and creating a usable interface to the *** conditions are important for any metadata system,but here the specification is tied to our framework for metadata quality based on the situation-specific needs for *** ideas are described,and their interrelationships are explored.

关键词： Metadata Standards Conformance Usability Metadata quality

Stretching the limits of maximal voluntary eccentric force production in vivo

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Journal of Sport and Health Science 2018年第3期7卷 275-281页

作者： daniel Hahn Human Movement Science Faculty of Sport Science Ruhr-University Bochum School of Human Movement and Nutrition Sciences University of Queensland

During eccentric contractions,muscular force production capacity is enhanced compared to isometric *** this is well accepted in terms of muscle mechanics,maximal voluntary eccentric contractions are associated with neural inhibition that prevents increased force production of in vivo human ***,because it was shown that maximal voluntary eccentric forces can exceed maximum isometric forces by a factor of 1.2-1.4,this review focuses on the question of whether the absent eccentric force enhancement,as observed in many studies,can unambiguously be attributed to an inherent neural ***,we demonstrate that participant familiarization,preload,and fascicle behavior are crucial factors influencing maximal voluntary eccentric force ***,we show that muscle mechanics such as muscle length,lengthening velocity,and stretch amplitude interact when it comes to maximal voluntary eccentric force ***,we discuss the diverging findings on neural inhibition during maximal voluntary eccentric *** there was no inhibition of the major motor pathways in the presence of enhanced maximal voluntary eccentric forces,further research is needed to test the concept of neural inhibition and to understand why maximal voluntary force production is reduced compared to the force capacity of isolated muscle preparations.

关键词： Active lengthening Eccentric contraction Inhibition Muscle Neural control

Effects of longwall-induced stress and deformation on the stability and mechanical integrity of shale gas wells drilled through a longwall abutment pillar

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International Journal of Mining Science and Technology 2017年第1期27卷 115-120页

作者： daniel W.H.Su National Institute for Occupational Safety and Health Bruceton 15236PAUSA

This paper presents the results of a comprehensive study conducted by CONSOL Energy, Marcellus Shale Coalition, and Pennsylvania Coal Association to evaluate the effects of longwall-induced subsurface deformations on the mechanical integrity of shale gas wells drilled over a longwall abutment *** primary objective is to demonstrate that a properly constructed gas well in a standard longwall abutment pillar can maintain mechanical integrity during and after mining operations. A study site was selected over a southwestern Pennsylvania coal mine, which extracts 457-m-wide longwall faces under about 183 m of cover. Four test wells and four monitoring wells were drilled and installed over a 38-m by84-m centers abutment pillar. In addition to the test wells and monitoring wells, surface subsidence measurements and underground coal pillar pressure measurements were conducted as the 457-m-wide longwall panels on the south and north sides of the abutment pillar were mined by. To evaluate the resulting coal protection casing profile and lateral displacement, three separate 60-arm caliper surveys were conducted. This research represents a very important step and initiative to utilize the knowledge and science obtained from mining research to improve miner and public safety as well as the safety and health of the oil and gas industries.

关键词： Gas well Casing Abutment pillar Stability Safety and health Instrumentation Numerical simulation

Effects of Navier slip on unsteady flow of a reactive variable viscosity non-Newtonian fluid through a porous saturated medium with asymmetric convective boundary conditions

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Journal of Hydrodynamics 2015年第6期27卷 934-944页

作者： RUNDORA Lazarus MAKINDE Oluwole daniel Department of Mathematics and Applied Mathematics University of LimpopoTurfloop Campus Faculty of Military Science Stellenbosch University

A study on the effects of Navier slip, in conjunction with other flow parameters, on unsteady flow of reactive variable viscosity third-grade fluid through a porous saturated medium with asymmetric convective boundary conditions is presented. The channel walls are assumed to be subjected to asymmetric convective heat exchange with the ambient, and exothermic chemical reactions take place within the flow system. The heat exchange with the ambient obeys Newton＇s law of cooling. The coupled equations, arising from the law of conservation of momentum and the first law of thermodynamics, then the derived system are non- dimensionalised and solved using a semi-implicit finite difference scheme. The lower wall slip parameter is observed to increase the fluid velocity profiles, whereas the upper wall slip parameter retards them because of backflow at the upper channel wall. Heat pro- duction in the fluid is seen to increase with the slip parameters. The wall shear stress increases with the slip parameters while the wall heat transfer rate is largely unaltered by the lower wall slip parameter but marginally increased by the upper wall slip parameter.

关键词： Navier slip saturated porous medium third-grade fluid temperature dependent viscosity convective boundary condi-tions

Leveraging Hazard,Exposure,and Social Vulnerability Data to Assess Flood Risk to Indigenous Communities in Canada

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International Journal of Disaster Risk Science 2021年第6期12卷 821-838页

作者： Liton Chakraborty Jason Thistlethwaite Andrea Minano daniel Henstra daniel Scott Public Safety Canada.Ottawa.ON K1A OPS.Canada Department of Geography and Environmental Management.Faculty of En\imnmcnt.University of Waleiioo Waicrloo.ON N2A 0E9.Canada School of En\imnmcnt.Enterprise and De\elopmont.Faculty of Environment University of WaterlooWaterloo.ON N2L 3GICanada Department of Political Science University of Waterloo.Waterloo.ON N2L 3GL Canada

This study integrates novel data on 100-year flood hazard extents,exposure of residential properties,and place-based social vulnerability to comprehensively assess and compare flood risk between Indigenous communities living on 985 reserve lands and other Canadian communities across 3701 census ***-scale exposure of residential properties to fluvial,pluvial,and coastal flooding was estimated at the 100-year return period.A social vulnerability index(SVI)was developed and included 49 variables from the national census that represent demographic,social,economic,cultural,and infrastructure/community indicators of *** information system-based bivariate choropleth mapping of the composite SVI scores and of flood exposure of residential properties and population was completed to assess the spatial variation of flood *** found that about 81%of the 985 Indigenous land reserves had some flood exposure that impacted either population or residential *** analysis indicates that residential property-level flood exposure is similar between non-Indigenous and Indigenous communities,but socioeconomic vulnerability is higher on reserve lands,which confirms that the overall risk of Indigenous communities is *** suggest the need for more local verification of flood risk in Indigenous communities to address uncertainty in national scale analysis.

关键词： Canada Flood risk assessment Indigenous communities Social vulnerability

Testing and modelling of transient adhesion phenomena in rolling-sliding contacts

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Friction 2024年第5期12卷 1016-1027页

作者： daniel KVARDA Alexander MEIERHOFER Klaus SIX Faculty of Mechanical Engineering Brno University of TechnologyBrno61669Czech Republic Virtual Vehicle Research GmbH Graz8010Austria

Transient adhesion effects in rolling–sliding contacts influence all aspects of train–track *** is of high importance specifically when these effects result in critically low adhesion,which poses a risk to traction and braking of railway *** study presents a model that can replicate the transient changes of the coefficient of adhesion with tested water and solid particle *** experimental data for the model are measured using a commercial ball-on-disc *** experimental results showed a liquid reservoir in front of the contact area that slowly reduces in *** observation was used in the modelling approach to divide the calculation into two stages where the reservoir is present and when it *** model was able to reproduce the occurrence of low adhesion region seen in experimental results with different particle concentrations.

关键词： coefficient of adhesion tribology transient effects wheel-rail contact

Three-dimensional finite difference analysis of shallow sprayed concrete tunnels crossing a reverse fault or a normal fault: A parametric study

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Frontiers of Structural and Civil Engineering 2020年第4期14卷 998-1011页

作者： Masoud RANJBARNIA Milad ZAHERI daniel DIAS Department of Geotechnical Engineering Faculty of Civil EngineeringUniversity of TabrizTabrizIran Schoo of Automotive and Transportation Engineering Hefei University of TechnologyHefei 230009China Universite Grenoble Alpes Grenoble F-38000France

Urban tunnels crossing faults are always at the risk of severe *** this paper,the efects of a reverse and a normal fault movement on a transversely crossing shallow shotcreted tunnel are investigated by 3D finite difference *** verifying the accuracy of the numerical simulation predictions with the centrifuge physical model results,a parametric study is then *** is,theleffects of various parameters such as the sprayed concrete thickness,the geo-mechanical properties of soil,the tunnel depth,and the fault plane dip angle are studied on the displacements of the ground surface and the tunnel structure,and on the plastic strains of the soil mass around *** results of each case of reverse and normal faulting are independently discussed and then compared with each *** is obtained that deeper tunnels show greater displacements for both types of faulting.

关键词： urban tunnel sprayed concrete reverse fault normal fault finite difference analysis

The current perspective of the PA 1957 gas well pillar study and its implications for longwall gas well pillars

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International Journal of Mining Science and Technology 2021年第1期31卷 117-126页

作者： Peter Zhang daniel Su Chris Mark CDC NIOSH Pittsburgh Mining Research DivisionPittsburghPA 15236USA Mine Safety and Health Administration PittsburghPA 15217USA

Many states rely upon the Pennsylvania 1957 Gas Well Pillar Study to evaluate the coal barrier surrounding gas *** study included 77 gas well failure cases that occurred in the Pittsburgh and Freeport coal seams over a 25-year *** the time,coal was mined using the room-and-pillar mining method with full or partial pillar recovery,and square or rectangle pillars surrounding the gas wells were left to protect the *** study provided guidelines for pillar sizes under different overburden depths up to 213 m(700 ft).The 1957 study has also been used to determine gas well pillar sizes in longwall mines since longwall mining began in the 1970 *** original study was developed for room-and-pillar mining and could be applied to gas wells in longwall chain pillars under shallow ***,under deep cover,severe deformations in gas wells have occurred in longwall chain ***,with a better understanding of coal pillar mechanics,new insight into subsidence movements induced by retreat mining,and advances in numerical modeling,it has become both critically important and feasible to evaluate the adequacy of the 1957 study for longwall gas well *** this paper,the data from the 1957 study is analyzed from a new perspective by considering various factors,including overburden depth,failure location,failure time,pillar safety factor(SF),and floor *** pillar SF and floor pressure are calculated by considering abutment pressure induced by full pillar recovery.A statistical analysis is performed to find correlations between various factors and helps identify the most significant factors for the stability of gas wells influenced by retreat *** analyzing the data from the 1957 study,the guidelines for gas well pillars in the 1957 study are evaluated for their adequacy for roomand-pillar mining and their applicability to longwall *** modeling is used to model the stability of gas wells by quantifying the mining-induced s

关键词： Gas well pillar Pennsylvania 1957 gas well pillar study Room-and-pillar mining Longwall mining

A Two-Player Coalition Cooperative Scheme for the Bodyguard Allocation Problem

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Journal of Computer Science & Technology 2018年第4期33卷 823-837页

作者： Jose Alberto Fernandez-Zepedu daniel Brubeck-Salcedo daniel Fajardo-Delgado Hector Zatarain-Aceves Department of Computer Science Center for Scientific Research and Higher Education of Ensenada Ensenada BC 22860 Mexico Department of Systems and Computation Instituto Technol6gico de Ciudad Guzmdn Guzmdn JAL 49100 Mexico

We address the bodyguard allocation problem （BAP）, an optimization problem that illustrates the conflict of interest between two classes of processes with contradictory preferences within a distributed system. While a class of processes prefers to minimize its distance to a particular process called the root, the other class prefers to maximize it; at the same time, all the processes seek to build a communication spanning tree with the maximum social welfare. The two state-of-the-art algorithms for this problem always guarantee the generation of a spanning tree that satisfies a condition of Nash equilibrium in the system; however, such a tree does not necessarily produce the maximum social welfare. In this paper, we propose a two-player coalition cooperative scheme for BAP, which allows some processes to perturb or break a Nash equilibrium to find another one with a better social welfare. By using this cooperative scheme, we propose a new algorithm called FFC-BAPs for BAP. We present both theoretical and empirical analyses which show that this algorithm produces better quality approximate solutions than former algorithms for BAP.

关键词： bodyguard allocation problem coalitional game graph algorithm Nash equilibrium