Theoretical modeling of the tensile behavior of low-twist staple yarns: Part I – theoretical model

2005 ◽  
Vol 96 (2) ◽  
pp. 61-68 ◽  
Author(s):  
X. Shao ◽  
Y. Qiu ◽  
Y. Wang
2020 ◽  
Vol 236 ◽  
pp. 117617 ◽  
Author(s):  
Ernesto Grande ◽  
Gabriele Milani ◽  
Maura Imbimbo

1998 ◽  
Vol 120 (3) ◽  
pp. 616-621 ◽  
Author(s):  
M. Visscher ◽  
D. Dowson ◽  
C. M. Taylor

This paper presents experimental results of motored engine tests on the wear and profile development of a twin-land oil-control ring. It is shown that the roughness height of the plateau honed liner decreases during running-in, indicating that the deeper grooves remain unaffected. The piston lands are much smoother, and do not show a significant overall change in surface roughness. The profile development results are compared with computer predictions in order to verify the theoretical modeling. It is indicated that the worn land profiles remain tapered, with an inclination resembling the twist angle of the ring. However, there remains a difference in the experimental and the numerically predicted land inclinations. This is probably due to the piston tilt, which was not included in the theoretical model.


2021 ◽  
Author(s):  
Qizhong Mao ◽  
Steven Jacobs ◽  
Waleed Amjad ◽  
Vagelis Hristidis ◽  
Vassilis J. Tsotras ◽  
...  

AbstractModern NoSQL database systems use log-structured merge (LSM) storage architectures to support high write throughput. LSM architectures aggregate writes in a mutableMemTable(stored in memory), which is regularly flushed to disk, creating a new immutable file called anSSTable. Some of the SSTables are chosen to be periodicallymerged—replaced with a single SSTable containing their union. Amergepolicy(a.k.a. compaction policy) specifies when to do merges and which SSTables to combine. Abounded depthmerge policy is one that guarantees that the number of SSTables never exceeds a given parameterk, typically in the range 3–10. Bounded depth policies are useful in applications where low read latency is crucial, but they and their underlying combinatorics are not yet well understood. This paper compares several bounded depth policies, including representative policies from industrial NoSQL databases and two new ones based on recent theoretical modeling, as well as the standard Tiered policy and Leveled policy. The results validate the proposed theoretical model and show that, compared to the existing policies, the newly proposed policies can have substantially lower write amplification with comparable read amplification.


2020 ◽  
Vol 71 (6) ◽  
pp. 406-412
Author(s):  
Martin Králik ◽  
Matej Goraus ◽  
Emil Pinčík

AbstractThe presented experiments and studies are intended for photovoltaic applications of crystalline silicon. This work deals with chemical treatment of the surface of n-type silicon wafers with different resistivity to reduce their reflectivity. Chemical surface treatment of silicon is an alternative method to using the antireflection layer. Optical losses caused by the reflection of light from the surface of the solar cells significantly reduce their efficiency. The investigated samples were prepared by the electrochemical etching method in the solution based on hydrofluoric acid and ethanol. The analysis of the prepared samples is divided into two parts, namely experimental measurements, and theoretical modeling. Experimental measurements are performed using UV-VIS spectroscopy, spectroscopic ellipsometry and SEM microscopy. Theoretical modeling is based on the construction and optimization of theoretical model of optical response (reflectivity and ellipsometric parameters) to determine the effective refractive index and thickness of formed structure. Effective refractive index of studied samples in theoretical model of optical response is based on Looyenga effective medium approximation and Tauc-Lorentz dispersion model.


2013 ◽  
Vol 7 (2) ◽  
pp. 1-18
Author(s):  
Adi Schnytzer ◽  
Sara Westreich

There have been many attempts, theoretical and empirical, to explain the persistence of a favorite-longshot bias in various horse betting markets. Most recently, Snowberg and Wolfers (2010) have shown that the data for the US markets support a “misperceptions of probability” approach in line with prospect theory over a neoclassical approach of the Quandt (1986) type. However, their paper suffers from two basic difficulties which beset much of this literature. First, the theoretical model used fails to allow for the existence of horse betting markets which either display no such bias (or a reverse bias) as in Hong Kong and at least one large Australian market (Busche and Hall, 1988, Schnytzer, Shilony and Thorne, 2003 and Luppi and Schnytzer, 2008). Second, econometric testing and theoretical modeling are facilitated by the highly unrealistic assumption that the betting population is homogeneous with respect to either information or attitude to risk or (usually) both. Our purpose is to show that allowing for heterogeneous betting populations (in terms of both attitude to risk and access to information) permits the explanation for the different biases (or their absence) observed in different markets accommodating both a framework of rational bettors and the requirements of prospect theory. We conclude with empirical support for our model.


Author(s):  
Timothy Besley ◽  
Torsten Persson

This chapter attempts to integrate two different strands of research on political violence, developing a theoretical model to analyze the common roots of repression and civil war. Under specific assumptions about the conflict technology, it shows that peace, repression (one-sided violence), and civil war (two-sided violence) become ordered states depending on a common underlying latent variable, which is shifted by shocks to the value of public goods, wages, aid, and resource rents. But these effects only emerge when political institutions do not provide sufficient checks and balances on the ruling group or adequate protection for those excluded from power. The chapter also shows how to start bridging the gap between theoretical modeling and econometric testing. Under specific assumptions on what can be observed, the predictions from the model can be taken to the data by estimating either an ordered logit or the conditional probability of transition from peace to violence or from non-civil war to civil war. The empirical strategy here is much sharper than in earlier chapters and shows that the kind of theory we are building can help us approach the data in a specific way.


1989 ◽  
Vol 111 (2) ◽  
pp. 157-161 ◽  
Author(s):  
E. Suhir

We discuss the role of theoretical and, in particular, analytical modeling in mechanical problems for electronic packaging, including requirements for a feasible theoretical model, how such a model is developed, the role of mathematics, what can be gained by using theoretical modeling, as well as the interaction of analytical, numerical (computer-aided) and experimental models. Peculiarities of theoretical modeling in Structural Analysis are also briefly discussed.


Nanoscale ◽  
2020 ◽  
Vol 12 (45) ◽  
pp. 23028-23035
Author(s):  
Artem R. Khabibullin ◽  
Alexander L. Efros ◽  
Steven C. Erwin

Theoretical modeling of wavefunction overlap in nanocrystal solids elucidates the important role played by ligands in electron transport.


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