Cyclic behaviour of deep reinforced concrete coupling beams

Six half-scale models of reinforced concrete coupling beams with span/depth ratios ≤ 2.0 were tested under reversed cyclic load by a newly developed test method that can accurately simulate the boundary conditions of coupling beams in coupled shear wall structures. Five of them were conventionally reinforced and one was diagonally reinforced. Span/depth ratio and reinforcement layout were the main structural variables studied. Test results revealed that the deep conventionally reinforced coupling beams behaved quite differently from the ordinary beams in frame structures. Generally, shear failure was more likely to occur. Moreover, the additional longitudinal reinforcement bars (those placed near the centroidal axis) could contribute significantly to bending strength and therefore lead to an increase in shear demand. Nevertheless, the measured drift ratios of the conventionally reinforced coupling beams still reached 3·6-5·7%, which are not small for deep coupling beams. On the other hand, it was found that the provision of diagonal reinforcement radically changed the load resisting mechanism and significantly improved the energy dissipation capacity of the coupling beam. However, it had not improved the deformability of the coupling beam.published_or_final_versio

Stack and Queue Layouts via Layered Separators

It is known that every proper minor-closed class of graphs has bounded stack-number (a.k.a. book thickness and page number). While this includes notable graph families such as planar graphs and graphs of bounded genus, many other graph families are not closed under taking minors. For fixed $g$ and $k$, we show that every $n$-vertex graph that can be embedded on a surface of genus $g$ with at most $k$ crossings per edge has stack-number $\mathcal{O}(\log n)$; this includes $k$-planar graphs. The previously best known bound for the stack-number of these families was $\mathcal{O}(\sqrt{n})$, except in the case of $1$-planar graphs. Analogous results are proved for map graphs that can be embedded on a surface of fixed genus. None of these families is closed under taking minors. The main ingredient in the proof of these results is a construction proving that $n$-vertex graphs that admit constant layered separators have $\mathcal{O}(\log n)$ stack-number.Comment: Appears in the Proceedings of the 24th International Symposium on Graph Drawing and Network Visualization (GD 2016

Comparison between modern polar and temperate skeletal carbonate mineralogy and oxygen and carbon isotopes, Antarctic and Tasmanian shelves

Modern bryozoan skeletal mineralogy varies with seawater temperature: polar Antarctic bryozoans are mainly low-Mg calcite, whereas temperate Tasmanian bryozoans are predominantly high-Mg calcite with variable amounts of aragonite. Bivalve molluscs from both polar and temperate regions are mainly aragonite with variable amounts of low-Mg calcite. The o180 and o13C isotope fields of polar skeletons are clearly separated from the temperate fields, due to differences in seawater temperatures, levels of o13C in seawater and the circulation of seawater masses. 0180 values of bryozoa, benthic foraminifera and bivalve molluscs give near-equilibrium seawater temperatures. Small differences in 0180 and o13C values between skeletons are due to their variable growth rates. Meltwater effects are small (7%) in the polar Antarctic Sea and high (<25%) in the shallow Arctic Sea because ice sheets do not melt in the Antarctic region, whereas significant melting of ice sheets occurs in summer in the Arctic regions. Skeletal carbonate mineralogy and 0180 and o13C variations can be used in the recognition of ancient, non-tropical carbonate skeletons and carbonate rocks

Testing of coupling beams with equal end rotations maintained and local joint deformation allowed

The strength and ductility of the coupling beams in coupled shear walls can significantly affect the nonlinear behaviour and earthquake resistance of the whole building structure. However, although extensive testing of coupling beams has been performed, the boundary conditions-that the rotations at the two ends of a coupling beam are equal and that local deformation occurs at the beam-wall joints, which could have substantial influence on the test results-have not been correctly simulated. Herein, a new method of testing reinforced concrete coupling beams that ensures equal rotations at the ends of the beam specimen and takes into account local deformation at the beam-wall joints is developed. The method has been successfully applied to test typical reinforced concrete coupling beams with relatively small span/depth ratios and proven to be suitable for studying the post-peak behaviour and failure characteristics of short coupling beams. Test results obtained so far indicate that reinforced concrete coupling beams with small span/depth ratios behave quite differently from ordinary beams in frame structures and that the local deformation at beam-wall joints is quite substantial. Complete load-deflection curves have been acquired and the strength and ductility of the coupling beams evaluated.published_or_final_versio

ECoFFeS: A Software Using Evolutionary Computation for Feature Selection in Drug Discovery

Feature selection is of particular importance in the field of drug discovery. Many methods have been put forward for feature selection during recent decades. Among them, evolutionary computation has gained increasing attention owing to its superior global search ability. However, there still lacks a simple and efficient software for drug developers to take advantage of evolutionary computation for feature selection. To remedy this issue, in this paper, a user-friendly and standalone software, named ECoFFeS, is developed. ECoFFeS is expected to lower the entry barrier for drug developers to deal with feature selection problems at hand by using evolutionary algorithms. To the best of our knowledge, it is the first software integrating a set of evolutionary algorithms (including two modified evolutionary algorithms proposed by the authors) with various evaluation combinations for feature selection. Specifically, ECoFFeS considers both single-objective and multi-objective evolutionary algorithms, and both regression- and classification-based models to meet different requirements. Five data sets in drug discovery are collected in ECoFFeS. In addition, to reduce the total analysis time, the parallel execution technique is incorporated into ECoFFeS. The source code of ECoFFeS can be available from https://github.com/JiaweiHuang/ECoFFeS/

The Transformation Of Trust In China’s Alternative Food Networks: Disruption, Reconstruction, And Development

Food safety issues in China have received much scholarly attention, yet few studies systematically examined this matter through the lens of trust. More importantly, little is known about the transformation of different types of trust in the dynamic process of food production, provision, and consumption. We consider trust as an evolving interdependent relationship between different actors. We used the Beijing County Fair, a prominent ecological farmers’ market in China, as an example to examine the transformation of trust in China’s alternative food networks. We argue that although there has been a disruption of institutional trust among the general public since 2008 when the melamine-tainted milk scandal broke out, reconstruction of individual trust and development of organizational trust have been observed, along with the emergence and increasing popularity of alternative food networks. Based on more than six months of fieldwork on the emerging ecological agriculture sector in 13 provinces across China as well as monitoring of online discussions and posts, we analyze how various social factors—including but not limited to direct and indirect reciprocity, information, endogenous institutions, and altruism—have simultaneously contributed to the transformation of trust in China’s alternative food networks. The findings not only complement current social theories of trust, but also highlight an important yet understudied phenomenon whereby informal social mechanisms have been partially substituting for formal institutions and gradually have been building trust against the backdrop of the food safety crisis in China.published_or_final_versio

Dynamic response of multiple coplanar interface cracks between two dissimilar piezoelectric materials

The linear piezoelectricity theory is applied to investigate the dynamic response of coplanar interface cracks between two dissimilar piezoelectric materials subjected to the mechanical and electrical impacts. The number of cracks is arbitrary, and the interface cracks are assumed to be permeable for electric field. Integral transforms and dislocation density function are employed to reduce the problem to Cauchy singular integral equations. Numerical examples are given to show the effects of crack relative position and material property parameters on the variations of dynamic energy release rate.postprin

S3 as a flavour symmetry for quarks and leptons after the Daya Bay result on \theta 13

We present a model based on the flavour group S3 X Z3 X Z6 to explain the main features of fermion masses and mixing. In particular, in the neutrino sector the breaking of the S3 symmetry is responsible for a naturally small r=\Delta m^2_sol/\Delta m^2_atm and suitable next-to-leading order corrections bring \theta 13 at the level of ~ 0.13, fully compatible with the recent Daya Bay result. In the quark sector, the model accommodates the different mass hierarchies in the up and down quark sectors as well as the Cabibbo angle and Vcb (or Vub, depending on the charge assignment of the right-handed b-quark) in the correct range.Comment: 15 pages, 3 figure

Application of PGA on optimization of distribution of shopping centers

Series: Lecture notes in computer scienceAuthor name used in this publication: Chun-Tian ChengAuthor name used in this publication: Kwokwing Chau2004-2005 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe