Cost Optimization of Steel Beam-to-Column Connections using AVOA

The joint-bolt-African Vulture optimization algorithm(AVOA)model is proposed for the design of building connections to improve the stability of steel beam-to-column connections.For this algorithm,the type of steel is first determined,and the number of bolts needed by the corresponding steel type is referenced in Eurocode 3.Then,the bearing capacity of the joint can be calculated.The joint-bolt-AVOA model is established by substituting the bolt number required by the steel into the algorithm to obtain the optimal bolt number required while ensuring joint stability.The results show that the number of bolts required by the joint-bolt-AVOA model based on the stability of steel is lower than that calculated by Eurocode 3.Therefore,AVOA can effectively optimize the number of bolts needed in building connections and save resources.

The impact of political connections on firm pollution: New evidence based on heterogeneous environmental regulation

Increasing attention has been focused on the extent to which corporate political connections influence the growing pollution due to the rapid growth in the popularity of firm pollution in developing countries.We adopt a static threshold regression model to investigate the effects of heterogeneous environmental regulation on political connections and firm pollution based on the panel data from China’s A-share listed companies from 2012 to 2019.The empirical results show a non-linear relationship between the degree of political connection of listed company executives and the level of firm pollution.And the relationship between the two roughly presents a U-shaped relationship under the action of the marketincentive environmental regulation threshold.However,it roughly presents an inverted N-shaped relationship under the action of the command-control environmental regulation threshold.Additionally,the group test results show that the existence of regional and ownership heterogeneity causes certain differences in the environmental behaviour of politically connected enterprises.These findings indicate that diverse environmental regulations are needed to promote sustainable green development and to further expand the theoretical and practical exploration of political connections on firm pollution.

Shear Behaviors of Steel-Plate Connections for Timber-Concrete Composite Beams with Prefabricated Concrete Slabs

To promote the development of timber-concrete composite(TCC)structures,it is necessary to propose the assembly-type connections with high assembly efficiency and shear performances.This article presented the experimental results of the innovative steel-plate connections for TCC beams using prefabricated concrete slabs.The steel-plate connections consisted of the screws and the steel-plates.The steel-plates were partly embedded in the concrete slabs.The concrete slabs and the timber beams were connected by screws through the steel-plates.The parameters researched in this article included screw number,angle steel as the reinforcement for anchoring,and shallow notches on the timber surface to restrict the slip of the steel-plates.Experimental results were discussed in terms of failure modes,ultimate bearing capacities,and slip moduli.It was found that increasing the number of screws could lead to the obvious improvement on the ultimate bearing capacities and the slip moduli at the ultimate state;and the angle steel as the reinforcement showed the slight influence on the ultimate bearing capacities and the slip moduli.The application of the shallow notch can greatly improve the ultimate bearing capacities and the slip moduli.The calculation models for the ultimate bearing capacities and the slip moduli of the steel-plate connections with and without shallow notches were proposed,which showed good accuracy compared with the experimental results.

Experimental Study of Moso Bamboo to-Steel Connections with Embedded Grouting Materials

Moso bamboos have attracted excessive attention as a renewable green building material to the concept of sustainable development.In this paper,the 20 bolted Moso bamboo connection specimens with embedded steel plates and grouting materials were designed according to connection configurations with different bolt diameters and end distance of bolt holes,and their bearing capacities and failure modes were analyzed by static tension tests.According to the test results of all connectors,the failure modes of the specimens are divided into four categories,and the effects of bolt diameter and bolt hole end distance on the connection bearing capacity and failure mode are analyzed.The test results show that the deformation and failure process can be divided into four stages.The main influence factor of connector bearing capacity is bolt diameter.Connectors can be divided into four failure modes,and brittle failure can be avoided by adopting certain structural measures.Filling with grouting material can improve the bearing capacity of joints.Due to the large variability of bamboo,further experiments are needed.

The Effect of Self-Investment on Hoarding Tendency of Chinese College Students:Role of Psychological Connections

Because of factors such as energy and time one invests in an object,the stronger the connection,value,and reluc-tance to lose said object individual will have.Hoarding behavior arises when individuals incorporate a strong attachment with themselves to an object.The purpose of this study is to examine the effect of self-investment on hoarding tendency and the roles of possession-self link and liking level in this connection.A hypothetical model of the relationship between self-investment,possession-self link,liking level,and hoarding tendency was tested.A convenience sampling method was used to survey 450 college students in Yunnan Province on either a paper-based or online self-report scale.The data were collected using self-investment,possession-self link,and liking level questionnaires,as well as the Saving Inventory Revised.Results showed positive relationship between the study variables,ranging from 0.37 to 0.87.College students’self-investment had a direct positive pre-dictive effect on hoarding tendency;self-investment,in turn,indirectly predicted hoarding tendency through the mediating effect of possession-self link;and individual liking level of items had a moderating effect for self-invest-ment on the possession-self link.This study shows how self-investment affects the hoarding tendency of college students,and the results of this study also help demonstrate the value of self-investment and possession-self link in optimizing students’hoarding tendency and thus promoting good psychological status.

An Improved Time Feedforward Connections Recurrent Neural Networks

Recurrent Neural Networks(RNNs)have been widely applied to deal with temporal problems,such as flood forecasting and financial data processing.On the one hand,traditional RNNs models amplify the gradient issue due to the strict time serial dependency,making it difficult to realize a long-term memory function.On the other hand,RNNs cells are highly complex,which will signifi-cantly increase computational complexity and cause waste of computational resources during model training.In this paper,an improved Time Feedforward Connections Recurrent Neural Networks(TFC-RNNs)model was first proposed to address the gradient issue.A parallel branch was introduced for the hidden state at time t−2 to be directly transferred to time t without the nonlinear transforma-tion at time t−1.This is effective in improving the long-term dependence of RNNs.Then,a novel cell structure named Single Gate Recurrent Unit(SGRU)was presented.This cell structure can reduce the number of parameters for RNNs cell,consequently reducing the computational complexity.Next,applying SGRU to TFC-RNNs as a new TFC-SGRU model solves the above two difficulties.Finally,the performance of our proposed TFC-SGRU was verified through sev-eral experiments in terms of long-term memory and anti-interference capabilities.Experimental results demonstrated that our proposed TFC-SGRU model can cap-ture helpful information with time step 1500 and effectively filter out the noise.The TFC-SGRU model accuracy is better than the LSTM and GRU models regarding language processing ability.

Lightweight Technologies in Sustainable Architecture:The Importance of Connections in Disassembly

The aim of this paper is to investigate the role of lightweight structures and connections in the DfD(design for disassembly)framework.The construction sector is facing pressure to reduce its environmental impact,which has led to heightened interest in DfD as a strategy for transitioning from a linear“Cradle to Grave”economic model to a circular“Cradle to Cradle”model.At the social level,DfD’s technological and spatial flexibility provides opportunities for self-build and self-maintenance processes,which can decrease land consumption and reduce costs for both owners and tenants.In this context,lightweight structures and connections are crucial for enabling these processes.The methodology used for analysis involves breaking down three technological elements chosen from three different projects to evaluate ease of disassembly,flexibility,potential for reuse,and recyclability.As a result,this paper aims to promote the development of an abacus of existing technological solutions,to provide designers with a tool that can help them pursue DfD strategies.

Age-related hearing loss accelerates the decline in fast speech comprehension and the decompensation of cortical network connections

Patients with age-related hearing loss face hearing difficulties in daily life.The causes of age-related hearing loss are complex and include changes in peripheral hearing,central processing,and cognitive-related abilities.Furthermore,the factors by which aging relates to hearing loss via changes in audito ry processing ability are still unclear.In this cross-sectional study,we evaluated 27 older adults(over 60 years old) with age-related hearing loss,21 older adults(over 60years old) with normal hearing,and 30 younger subjects(18-30 years old) with normal hearing.We used the outcome of the uppe r-threshold test,including the time-compressed thres h old and the speech recognition threshold in noisy conditions,as a behavioral indicator of auditory processing ability.We also used electroencephalogra p hy to identify presbycusis-related abnormalities in the brain while the participants were in a spontaneous resting state.The timecompressed threshold and speech recognition threshold data indicated significant diffe rences among the groups.In patients with age-related hearing loss,information masking(babble noise) had a greater effect than energy masking(speech-shaped noise) on processing difficulties.In terms of resting-state electroencephalography signals,we observed enhanced fro ntal lobe(Brodmann’s area,BA11) activation in the older adults with normal hearing compared with the younger participants with normal hearing,and greater activation in the parietal(BA7) and occipital(BA19) lobes in the individuals with age-related hearing loss compared with the younger adults.Our functional connection analysis suggested that compared with younger people,the older adults with normal hearing exhibited enhanced connections among networks,including the default mode network,sensorimotor network,cingulo-opercular network,occipital network,and frontoparietal network.These results suggest that both normal aging and the development of age-related hearing loss have a negative effect on advanced audito ry processing capabilities and that hearing loss accele rates the decline in speech comprehension,especially in speech competition situations.Older adults with normal hearing may have increased compensatory attentional resource recruitment represented by the to p-down active listening mechanism,while those with age-related hearing loss exhibit decompensation of network connections involving multisensory integration.

Analytical Investigation into the Rotational Performance of Glulam Bolted Beam-Column Connections under Coupled Bending Moment and Shear Force

Considering the glulam beam-column connection form and the number of bolts,monotonic loading test and finite element analysis was carried out on 9 connection specimens in 3 groups to study the rotational performance and failure mode of the connection.The test results revealed that compared with U-shaped connectors,T-shaped connectors can effectively improve the ductility of connections,and the increase in the number of bolts can reduce the initial stiffness and ductility of connections.By theoretical analysis,formulas for calculating the initial stiffness and ultimate moment of connections were deduced.Subsequently,the moment-rotation theoretical model of connections was established based on the formulas,which were validated according to the test data and simulation results.The proposed model can not only improve the current theoretical system of heavy-duty glulam beam-column structure but also provide a theoretical basis for calculating the mechanical properties of the glulam beam-column connection.

基于AOO与IBM Connections的社会化分享设计

着力于增强办公软件的社会化分享能力,采用品牌架构、易用性、一致性、反馈机制和用户归属感等设计方法,整合办公软件与社交媒体的功能,致力于提升办公软件的用户体验,以云技术为技术支持,设计出一款基于Apache Open Office(AOO)的社会化分享工具,实现了AOO与IBM Connections的集成,提升了AOO的社会化分享能力,开创了办公软件与IM以及社交媒体结合的先例。

Seismic fragility of flexible pipeline connections in a base isolated medical building

Flexible pipelines are often used to connect hard pipes from a foundation to a superstructure to accommodate large deformation in the base isolation layer during an earthquake. Although Chinese seismic design guidelines suggest several confi gurations, they are diff erent from the designs that have been proven in practice, e.g., Japanese styles, and extensive experimental investigation into their seismic performance is required. Three types of seals, rubber-, metal- and asbestinebased, were tested quasi-statically with infi lled pressurized water at 2.5 MPa. The asbestine-based seal leaked at a smaller deformation than the other two types of seals. Based on the test results, three damage states were defi ned and the deformation capacity was estimated. To evaluate their performance, a three-dimensional model of a base-isolated medical building was developed using OpenSees, with the fl exible pipelines simulated by a mechanical model calibrated from the experimental data. A probabilistic seismic demand model and the fragility function of the fl exible pipelines were then developed to evaluate the seismic performance.

Shaking table test and numerical analysis of a 1:12 scale model of a special concentrically braced steel frame with pinned connections

This paper describes shaking table tests of a 1：12 scale model of a special concentrically braced steel frame with pinned connections, which was fabricated according to a one-bay braced frame selected from a typical main factory building of a large thermal power plant. In order to investigate the seismic performance of this type of structure, several ground motion accelerations with different levels for seismic intensity Ⅷ, based on the Chinese Code for Seismic Design of Buildings, were selected to excite the model. The results show that the design methods of the members and the connections are adequate and that the structural system will perform well in regions of high seismicity. In addition to the tests, numerical simulations were also conducted and the results showed good agreement with the test results. Thus, the numerical model is shown to be accurate and the beam element can be used to model this structural system.

Chaos in complex motor networks induced by Newman-Watts small-world connections

We investigate how dynamical behaviours of complex motor networks depend on the Newman-Watts small-world （NWSW） connections. Network elements are described by the permanent magnet synchronous motor （PMSM） with the values of parameters at which each individual PMSM is stable. It is found that with the increase of connection probability p, the motor in networks becomes periodic and falls into chaotic motion as p further increases. These phenomena imply that NWSW connections can induce and enhance chaos in motor networks. The possible mechanism behind the action of NWSW connections is addressed based on stability theory.

Method for Functional Design of Axiomatic Design Based on Connections

Axiomatic design（AD） is a popular design method,and satisfying the independence axiom is the basis of AD.However,AD doesn＇t provide methods to decompose functions then keep them independent and to handle coupled design.A few of ways of handling coupled design are mainly passive resolutions when coupled design exists,but not efficient to each product design.Hence,this paper presents an innovative approach to design and decompose functions of complex products based on functional connections,aiming at actively avoiding functional coupling.By contrasting with component networks,four kinds of relations among functions are identified,including spatial,energy,material,and information connection.Then the definitions of these relations and the dominant connection are given.Based on the definitions,the principles of functional decomposition and design are developed,in which each non-leaf function is broken into sub functions centered on its dominant connection with avoidance of functional cross and coupling,and sequentially satisfies the independence axiom.Then the operational flow of the proposed approach is constructed.Determining the dominant connection of a function,decomposing the function into sub functions in terms of the dominant connection and reverse examination and optimization are planed as the core steps in each zigzagging.Input process output（IPO） analysis is introduced to obtain the dominant connection of a function,some rules for examining and optimizing the decomposition results reversely according to oriented object theory are presented as well.An illustrative example about the pouring function of squeeze casting equipments presented demonstrates how to use the proposed approach,and indicates its effectiveness.The proposed approach expands the principles of AD,constructs a guidance policy for independent functional design of complex products based on AD,and can help decrease or actively avoid coupled design and improve design efficiency.

Mechanical Properties of Moso Bamboo Connections with External Clamp Steel Plates

The Moso bamboo,a renewable green building material used in various new green buildings,have received exten-sive attention with the promotion of the concept of green buildings.To explore the mechanical properties of Moso bamboo connections with external clamp steel plates,the 16 specimens were designed by changing the bolt diameters and the end distances of the bolt holes.Their static tension tests were conducted to investigate bearing capacities and failure modes of different connection configurations.Based on test results,three failure modes of these connections were obtained,including the shear failure of bolt shank,bearing failure of bolt hole and punch-ing shear failure of the Moso bamboo.The influence of bolt diameters and end distances of bolt holes on bearing capacities of the connections was quantitatively analyzed.Based on a simplified mechanical model,the analytical models were deduced for the bolt shear failure and the bearing failure of bolt holes.The results showed that the predictive values are in substantial agreement with the experimental results.Finally,the design and manufacturing suggestions are recommended for this Moso bamboo connections.

杜克大学跨学科人才培养项目模式的建构研究--基于2014-2018 Bass Connections年度评估报告分析

本文从国际比较视角,分析了跨学科人才培养模式中的项目模式对跨学科学习和研究的深刻意义。以杜克大学的Bass Connections项目为研究对象,通过对杜克大学2014—2018年的Bass Connections Annual Evaluation Reports进行文本分析,从三个维度总结概括Bass Connections项目模式,在分析中发现全新的发展评估框架,科学、清晰的战略计划和专业的顶层设计,项目形式的丰富性与参与主体的多样化促进了Bass Connections项目的快速成熟。Bass Connections项目已经成为杜克大学实施跨学科研究和教学的标志,为我国“双一流”建设高校在人才培养和学科建设方面构建一流的跨学科人才培养模式提供了先进理念和实践层面的启示。

Lotus Connections应用场景分析

Lotus Connections是IBM推出的企业内部社交化平台,它提供个人档案、社区、博客、社会书签、活动等协作组件,通过Lotus Connections平台上各种协作组件的使用,能加强企业内部人与人之间的沟通协作,促进企业内部信息更快地传播和分享,提升企业内部知识的价值,促进企业内部社交化思维和工作方式的转变。

Climate Changes Consequences from Sun-Earth Connections and Anthropogenic Relationships

This paper is a study to understand how climate changed last fifty years. There are two theories: the first one considers the solar variability and the influence of those alterations on climate;the second one blames human activity and the consequences on temperatures and disruption on the environment created by humans. Our conclusions pointed out that dimensions involved between Earth and Sun, and Earth/Atmosphere, the second one can disturb the temperature on Earth’s surface and make seasonality variations impossible to be explained only by Sun/Earth connections.

Simplified seismic fatigue evaluation for rigid steel connections

A simplified fatigue-life model is proposed for assessing the seismic inelastic rotational capacity of steel connections.First relations are developed for rigid steel connections under lateral loading.Next this is extended to account for the effects of the welded steel moment frame(WSMF)connections of the so-called pre-Northridge type.The seismic fatigue theory is validated against experimental results.The experiments were conducted under increasing ductility amplitudes until the onset of fiacture.Miner'rule was used to convert the test results to given an equivalent constant amplitude cyclic fatigue life.Satisfactory agreement is obtained when comparing the experimental observations with the theoretical predictions.

Experimental and Numerical Studies of Failure Modes and Load-Carrying Capacity of Through-Diaphragm Connections

Shear failure in panel zones and plastic hinges in steel beams are the two major failure modes of connections between concrete-filled steel tubular(CFST) columns and steel beams. To investigate the behavior of this type of connection in both modes,two through-diaphragm connections were tested under cyclic and monotonic loadings and the load-carrying capacity,ductility,and strength of degradation of connections were discussed. Using ABAQUS software,we developed nonlinear finite-element models(FEMs) to simulate the load-carrying capacity and failure modes of the connections under monotonic loading. The finite-element(FE) analysis and test results showed reasonable agreement for the through-diaphragm connections,which confirms the accuracy of FEMs in predicting the load-carrying capacity and failure modes of connections. Based on the validated FEM,a parametric study was then conducted to investigate the infl uence of the thicknesses of the tube and diaphragm on the load-carrying capacity and failure modes of these connections. The results indicate that the strength,stiff ness,and load-carrying capacity are infl uenced less by the thickness of the diaphragm,and more by the thickness of the steel tube. According to the FE analysis results,it can be found that the critical condition between the two failure modes is determined by the shear resistance and bending resistance.