scholarly journals The number of critical connection vectors of L-superadditive structure functions

1989 ◽  
Vol 21 (4) ◽  
pp. 930-932 ◽  
Author(s):  
Emad El-Neweihi ◽  
Fan C. Meng
Keyword(s):  
Structure Function ◽  
Structure Functions ◽  
Performance Level ◽  
Performance Levels ◽  
Relevance Condition

A conjecture due to Block et al. (1989), concerning the number of critical connection vectors to the various performance levels of a discrete L-superadditive structure function, is proved. When the components of the discrete L-superadditive structure function are further assumed to satisfy a certain relevance condition due to Griffith (1980), it is shown that there is exactly one critical connection vector to each performance level.

scholarly journals The number of critical connection vectors of L-superadditive structure functions

1989 ◽  
Vol 21 (04) ◽  
pp. 930-932
Author(s):  
Emad El-Neweihi ◽  
Fan C. Meng
Keyword(s):  
Structure Function ◽  
Structure Functions ◽  
Performance Level ◽  
Performance Levels ◽  
Relevance Condition

A conjecture due to Block et al. (1989), concerning the number of critical connection vectors to the various performance levels of a discrete L-superadditive structure function, is proved. When the components of the discrete L-superadditive structure function are further assumed to satisfy a certain relevance condition due to Griffith (1980), it is shown that there is exactly one critical connection vector to each performance level.

IP Dynamic Anti-Rust Test, Lubricating Greases

1969 ◽  
Vol 184 (6) ◽  
pp. 23-31
Author(s):  
F. E. H. Spicer
Keyword(s):  
Performance Level ◽  
Test Method ◽  
European Countries ◽  
Distilled Water ◽  
Ball Bearings ◽  
Double Row ◽  
Performance Levels ◽  
Good Protection ◽  
Intermediate Performance

The Institute of Petroleum has recently published a test method (IP 220/67) for assessing the rust-prevention characteristics of greases. Specially selected and preserved double-row, self-aligning ball bearings are used as test specimens. The test, which lasts for 164 1/2 h, is dynamic, the grease film being produced and part of the test being performed with the bearings rotating partially submerged in distilled water. The performance of the grease is assessed by estimating the area of rust on the outer races of the test bearings. The precision of the test method was established by an extensive international correlation programme involving 30 laboratories from five European countries. This showed a precision which varied according to the performance level of the test greases. The results of tests with greases affording very good protection and with greases affording very poor protection against rusting gave better precision than results from greases with intermediate performance levels.

scholarly journals STRUCTURE FUNCTIONS IN DEEP INELASTIC LEPTON-NUCLEON SCATTERING

2000 ◽  
Vol 15 (supp01b) ◽  
pp. 467-494 ◽  
Author(s):  
MAX KLEIN
Keyword(s):  
Inelastic Scattering ◽  
Structure Function ◽  
Deep Inelastic Scattering ◽  
Gluon Distribution ◽  
Structure Functions ◽  
Heavy Flavor ◽  
Nucleon Scattering ◽  
High Q ◽  
Low X

This report presents the latest results on structure functions, as available at the Lepton-Photon Symposium 1999. It focuses on three experimental areas: new structure function measurements, in particular from HERA at low x and high Q2; results on light and heavy flavor densities; and determinations of the gluon distribution and of αs. As the talk was delivered at a historic moment and place, a few remarks were added recalling the exciting past and looking into the promising future of deep inelastic scattering (DIS).

scholarly journals Inverse Optimum Safety Factor Method for Reliability-Based Topology Optimization Applied to Free Vibrated Structures

2019 ◽  
pp. 8-19 ◽  
Author(s):  
Ghias Kharmanda ◽  
Imad R. Antypas ◽  
Alexey G. Dyachenko
Keyword(s):  
Topology Optimization ◽  
Structure Function ◽  
Modal Analysis ◽  
Safety Factor ◽  
Optimization Model ◽  
High Performance ◽  
Structural Type ◽  
Efficient Tool ◽  
Performance Levels ◽  
Reliability Level

Introduction. The classical topology optimization leads to a prediction of the structural type and overall layout, and gives a rough description of the shape of the outer as well as inner boundaries of the structure. However, the probabilistic topology optimization (or reliability-based topology optimization) model leads to several reliability-based topologies with high performance levels. The objective of this work is to provide an efficient tool to integrate the reliability-based topology optimization model into free vibrated structure. Materials and Methods. The developed tool is called inverse optimum safety method. When dealing with modal analysis, the choice of optimization domain is highly important in order to be able to eliminate material taking account of the constraints of fabrication and without affecting the structure function. This way the randomness can be applied on certain boundary parameters. Results. Numerical applications on free vibrated structures are presented to show the efficiency of the developed strategy. When considering a required reliability level, the resulting topology represents a different topology relative to the deterministic resulting one. Discussion and Conclusion. In addition to its simplified implementation, the developed inverse optimum safety factor strategy can be considered as a generative tool to provide the designer with several solutions for free vibrated structures with different performance levels.

scholarly journals Component-level Performance-based Seismic Assessment and Design Approach for Concrete Moment Frames

2016 ◽  
Vol 10 (1) ◽  
pp. 25-39
Author(s):  
Zhou Xinxian ◽  
Han Xiaolei ◽  
Ji Jing ◽  
Qi Yongle ◽  
Hang Chao
Keyword(s):  
Performance Indicator ◽  
Seismic Assessment ◽  
Performance Level ◽  
Statistical Distribution ◽  
Structural Performance ◽  
Structural Components ◽  
Moment Frames ◽  
Acceptance Criteria ◽  
Performance Levels ◽  
Critical Components

To solve the conservatism of acceptance criteria in ASCE/SEI 41 provisions, a new concept of component performance is put forward and an alternative method based on the statistical distribution of component performance levels to evaluate structural performance level is proposed. Independent component performance levels are redefined in detail and component performance indicator limits are developed, which are different from acceptance criteria for integral target performance level of entire building proposed by ASCE standards. Structural components are classified into critical components and general components. The relationship between structural performance levels and the statistical distribution of component performance levels, including performance levels of critical components, general components and non-structural components, is proposed. A framework for applying this method will be discussed in detailand implemented to a seven-story moment frame. It is concluded that this new evaluation method is simple and meaningful for performance-based seismic assessment and design.

scholarly journals The Observational Error of Automated Wind Reports from Aircraft

1986 ◽  
Vol 67 (2) ◽  
pp. 177-185 ◽  
Author(s):  
Lauren L. Morone
Keyword(s):  
Measurement Error ◽  
Structure Function ◽  
Error Variance ◽  
Structure Functions ◽  
Separation Distance ◽  
Observational Error ◽  
Random Measurement Error ◽  
Measurement Error Variance ◽  
Flight Level ◽  
Types Of Error

Data collected from aircraft equipped with AIDS (Aircraft Integrated Data System) instrumentation during the Global Weather Experiment year of 1979 are used to estimate the observational error of winds at flight level from this and other aircraft automated wind-reporting systems. Structure functions are computed from reports that are paired using specific criteria. The value of this function extrapolated to zero separation distance is an estimate of twice the random measurement-error variance of the AIDS-measured winds. Component-wind errors computed in this way range from 2.1 to 3.1 m · s−1 for the two months of data examined, January and August 1979. Observational error, specified in optimum-interpolation analyses to allow the analysis to distinguish among observations of differing quality, is composed of both measurement error and the error of unrepresentativeness. The latter type of error is a function of the resolvable scale of the analysis-prediction system. The structure function, which measures the variability of a field as a function of separation distance, includes both of these types of error. If the resolvable scale of an analysis procedure is known, an estimate of the observational error can be computed from the structure function at that particular distance. An observational error of 5.3 m · s−1 was computed for the u and v wind components for a sample resolvable scale of 300 km. The errors computed from the structure functions are compared to colocation statistics from radiosondes. The errors associated with automated wind reports are found to compare favorably with those estimated for radiosonde winds at that level.

Relationships between executive functions and occupational performance of children with medulloblastoma

2020 ◽  
pp. 030802262093985
Author(s):  
Gözde Önal ◽  
Meral Huri
Keyword(s):  
Executive Function ◽  
Correlation Analysis ◽  
Executive Functions ◽  
Performance Level ◽  
Typical Development ◽  
Occupational Performance ◽  
Performance Levels ◽  
Significant Relationships ◽  
Therapy Interventions ◽  
The Relationship

Introduction This study examines executive functions and occupational performances of children with medulloblastoma and children with typical development. The aim was to compare the executive function and occupational performance levels of children with medulloblastoma and children with typical development and to investigate the relationship between the executive function and occupational performance levels of children with medulloblastoma. Method Parents of 105 children (6–12 years) completed the Childhood Executive Function Inventory. A total of 105 children were administered the Canadian Occupational Performance Measurement to obtain information on occupational performance areas. Executive functions and occupational performance levels of children with medulloblastoma ( n = 52) and typical development ( n = 53) were compared. Correlation analysis was conducted between the executive functions and occupational performances of children with medulloblastoma. Results Executive function and occupational performance levels of children with medulloblastoma were lower than those with typical development. Significant relationships were found between the executive functions and occupational performances of children with medulloblastoma ( p < 0.05, p < 0.001). Conclusion It is clear that the executive functions of children with medulloblastoma significantly affect their occupational performance level. Client-centered, occupation-oriented cognitive therapy interventions prepared according to occupational therapy theories and models might be useful to increase the occupational performance level of children with medulloblastoma.

scholarly journals Froissart bound and self-similarity based models of proton structure functions

2018 ◽  
Vol 33 (08) ◽  
pp. 1850046 ◽  
Author(s):  
D. K. Choudhury ◽  
Baishali Saikia
Keyword(s):  
Structure Function ◽  
Cross Section ◽  
Structure Functions ◽  
Proton Structure Function ◽  
Self Similarity ◽  
Proton Proton ◽  
Proton Structure

Froissart bound implies that the total proton–proton cross-section (or equivalently proton structure function) cannot rise faster than [Formula: see text]. Compatibility of such behavior with the notion of self-similarity in proton structure function was suggested by us sometime back. In the present work, we generalize and improve it further by considering more recent self-similarity based models of proton structure functions and compare with recent data as well as with the model of Block, Durand, Ha and McKay.

scholarly journals EFFECT DUE TO COMPOSITENESS OF NUCLEONS IN DEEP INELASTIC LEPTON NUCLEUS SCATTERING

1992 ◽  
Vol 01 (04) ◽  
pp. 809-821 ◽  
Author(s):  
BO-QIANG MA
Keyword(s):  
Structure Function ◽  
Nuclear Structure ◽  
Light Cone ◽  
Degrees Of Freedom ◽  
Structure Functions ◽  
Nucleon Structure ◽  
Nucleon Structure Function ◽  
Nucleus Scattering ◽  
Quark Structure ◽  
Nuclear Structure Functions

The off-shell behaviors of bound nucleons in deep inelastic lepton nucleus scattering are discussed in two scenarios with the basic constituents chosen to be baryon-mesons and quark-gluons respectively in light-cone formalism. It is found that when taking into account the effect due to internal quark structure of nucleons, the derived scaling variable for bound nucleons and the calculated nuclear structure functions are different from those in considering the baryon-mesons as the effective elementary constituents. This implies that the pure baryon-meson descriptions of nuclei give the inaccurate off-shell behavior of the bound nucleon structure function, thereby the quark-gluons seem to be the most appropriate degrees of freedom for nuclear descriptions.

scholarly journals Towards mapping turbulence in the intra-cluster medium

2019 ◽  
Vol 629 ◽  
pp. A144 ◽  
Author(s):  
E. Cucchetti ◽  
N. Clerc ◽  
E. Pointecouteau ◽  
P. Peille ◽  
F. Pajot
Keyword(s):  
Structure Function ◽  
Spatial Scales ◽  
Companion Paper ◽  
Structure Functions ◽  
Order Structure ◽  
Sampling Variance ◽  
Function Estimation ◽  
X Ray ◽  
Spatially Resolved Spectroscopy ◽  
Field Unit

X-ray observations of the hot gas filling the intra-cluster medium (ICM) provide a wealth of information on the dynamics of clusters of galaxies. The global equilibrium of the ICM is believed to be ensured by non-thermal and thermal pressure support sources, among which gas movements and the dissipation of energy through turbulent motions. Accurate mapping of turbulence using X-ray emission lines is challenging due to the lack of spatially resolved spectroscopy. Only future instruments such as the X-ray Integral Field Unit (X-IFU) on Athena will have the spatial and spectral resolution to quantitatively investigate the ICM turbulence over a broad range of spatial scales. Powerful diagnostics for these studies are line shift and the line broadening maps, and the second-order structure function. When estimating these quantities, instruments will be limited by uncertainties of their measurements, and by the sampling variance (also known as cosmic variance) of the observation. Here, we extend the formalism started in our companion Paper I to include the effect of statistical uncertainties of measurements in the estimation of these line diagnostics, in particular for structure functions. We demonstrate that statistics contribute to the total variance through different terms, which depend on the geometry of the detector, the spatial binning and the nature of the turbulent field. These terms are particularly important when probing the small scales of the turbulence. An application of these equations is performed for the X-IFU, using synthetic turbulent velocity maps of a Coma-like cluster. Results are in excellent agreement with the formulas both for the structure function estimation (≤3%) and its variance (≤10%). The expressions derived here and in Paper I are generic, and ensure an estimation of the total errors in any X-ray measurement of turbulent structure functions. They also open the way for optimisations in the upcoming instrumentation and in observational strategies.

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