A non-probabilistic reliability topology optimization method based on aggregation function and matrix multiplication considering buckling response constraints

A non-probabilistic reliability topology optimization method is proposed based on the aggregation function and matrix multiplication.The expression of the geometric stiffness matrix is derived,the finite element linear buckling analysis is conducted,and the sensitivity solution of the linear buckling factor is achieved.For a specific problem in linear buckling topology optimization,a Heaviside projection function based on the exponential smooth growth is developed to eliminate the gray cells.The aggregation function method is used to consider the high-order eigenvalues,so as to obtain continuous sensitivity information and refined structural design.With cyclic matrix programming,a fast topology optimization method that can be used to efficiently obtain the unit assembly and sensitivity solution is conducted.To maximize the buckling load,under the constraint of the given buckling load,two types of topological optimization columns are constructed.The variable density method is used to achieve the topology optimization solution along with the moving asymptote optimization algorithm.The vertex method and the matching point method are used to carry out an uncertainty propagation analysis,and the non-probability reliability topology optimization method considering buckling responses is developed based on the transformation of non-probability reliability indices based on the characteristic distance.Finally,the differences in the structural topology optimization under different reliability degrees are illustrated by examples.

AGGREGATE SPECIAL FUNCTIONS TO APPROXIMATE PERMUTING TRI-HOMOMORPHISMS AND PERMUTING TRI-DERIVATIONS ASSOCIATED WITH A TRI-ADDITIVEψ-FUNCTIONAL INEQUALITY IN BANACH ALGEBRAS

In this paper,we define a new class of control functions through aggregate special functions.These class of control functions help us to stabilize and approximate a tri-additiveψ-functional inequality to get a better estimation for permuting tri-homomorphisms and permuting tri-derivations in unital C*-algebras and Banach algebras by the vector-valued alternative fixed point theorem.

Ceramsite Containing Iron Oxide and its Use as Functional Aggregate in Microwave Absorbing Cement-based Materials

Electromagnetic（EM） wave absorbing cement-based composite has promising applications in protecting civil and military buildings from electromagnetic interferences. A new idea of preparing EM wave absorbing cement-based composite is proposed by using ceramsite containing iron oxide as EM wave absorbing functional aggregate. The ceramsite was synthesized by adding 10 wt% Fe3O4 into clay and sintering at 1 200 ℃, which shows obvious dielectric and magnetic loss properties for electromagnetic wave. The maximum reflection loss（RL） of the concrete specimens prepared with the ceramsite is between-10.2--10.7 dB（corresponding to absorption greater than 90% EM energy） in the bandwidth of 8-18 GHz. In addition, the compressive strength at 28 days age of the concrete is 46 MPa, showing the potentiality of being used as structural components in buildings.

Generalization of the linguistic aggregation operator and its application in decision making

A generalization of the linguistic aggregation functions （or operators） is presented by using generalized and quasiarithmetic means. Firstly, the linguistic weighted generalized mean （LWGM） and the linguistic generalized ordered weighted averaging （LGOWA） operator are introduced. These aggregation functions use linguistic information and generalized means in the weighted average （WA） and in the ordered weighted averaging （OWA） function. They are very useful for uncertain situations where the available information cannot be assessed with numerical values but it is possible to use linguistic assessments. These aggregation operators generalize a wide range of aggregation operators that use linguistic information such as the linguistic generalized mean （LGM）, the linguistic OWA （LOWA） operator and the linguistic or- dered weighted quadratic averaging （LOWQA） operator. We also introduce a further generalization by using quasi-arithmetic means instead of generalized means obtaining the quasi-LWA and the quasi-LOWA operator. Finally, we develop an application of the new approach where we analyze a decision making problem regarding the selection of strategies.

An Efficient and Privacy-Preserving Data Aggregation Scheme Supporting Arbitrary Statistical Functions in IoT

The Internet of Things(IoT)has profoundly impacted our lives and has greatly revolutionized our lifestyle.The terminal devices in an IoT data aggregation application sense real-time data for the remote cloud server to achieve intelligent decisions.However,the high frequency of collecting user data will raise people concerns about personal privacy.In recent years,many privacy-preserving data aggregation schemes have been proposed.Unfortunately,most existing schemes cannot support either arbitrary aggregation functions,or dynamic user group management,or fault tolerance.In this paper,we propose an efficient and privacy-preserving data aggregation scheme.In the scheme,we design a lightweight encryption method to protect the user privacy by using a ring topology and a random location sequence.On this basis,the proposed scheme supports not only arbitrary aggregation functions,but also flexible dynamic user management.Furthermore,the scheme achieves faulttolerant capabilities by utilizing a future data buffering mechanism.Security analysis reveals that the scheme can achieve the desired security properties,and experimental evaluation results show the scheme's efficiency in terms of computational and communication overhead.

IS THE“DEGREE OF AGGREGATION”A FUNCTION OF THE AVERAGE AGGREGATE NUMBER,OR OF THE NUMBER OF AGGREGATES,OR BOTH?

Measurement of the average aggregate number of coaggregates(N_co)and evaluation Of the number of coaggregates([CoAg])in the region of increasing degree of aggregation shows that only N_co increases linearly with the concentration of the target molecules CE-In and BL-ol.

Microstructural Damage Evaluation of High Alumina Castables with Addition of Different Dimensions of Functional Aggregates After Several Thermal Shock Cycles

Refractory materials are subjected to mechanical and chemical loads during application,which respectively lead to fracture and corrosion. The understanding of the mechanical fracture and the microstructural modification after progressive thermal shocks is necessary for the suitable design of high performance refractory materials.The fracture process zone can be divided into two areas,where different toughening mechanisms are likely to take place： the crack tip and the following process region called wake region. In this study,the emphasis is laid on the microstructural mechanisms occurring in the wake region of the crack and the crack tip. Therefore,functional aggregates,namely fused eutectic aggregates of Al2O3- ZrO 2- SiO 2and Al2O3- ZrO 2,and andalusite,are added to a model high alumina castable formulation based on tabular alumina. The discrepancy in thermal behavior between aggregates and matrix as well as phase transformation such as mullite formation favor further the nucleation of microcracks that reduce the stress field at the level of the crack tip. Two different grain fractions of tabular alumina（ 0. 2- 0. 6 mm or2. 24- 3. 00 mm） are substituted by these functional aggregates. After sintering at 1 500 ℃ for 6 h,the samplesare quenched up to 10 times in air without pressure from950 ℃ to room temperature. The resulting elastic properties are examined after each thermal shock cycle,as well as the residual bending strength after 0,1,3,5,7and 10 thermal shocks. These results are correlated with Scanning Electron Microscopy analyses after the different thermal shock cycles.

前列腺素E1对原发性肾病综合征作用初探(英文)

Objective:To investigate the effect of prostaglandin E1 (PGE1) (Alprostadii injection) on patients with primary nephrotic syndrome(PNS). Methods: 37 patients with PNS were recruited to study the effect of prostaglandin E1 on platelet aggregation function [ PAG (5,) PAG( m ) ], serum total protein (TP) , albumin (Al),blood urea nitrogen(BUN) ,serum creatinine(Scr) ,cholesterol(CHO), triglyceride(TG), protein in 24-hour urine (Pr/24h) and platelet account (PLT). Results: TP, Al, CHO, TG, BUN, Scr, Pr/24h, PAG(5) and PAG(m) in PNS group before treatment were significantly different from those in control group(P＜0.05, P＜0.01) while no significant difference was found for PLT. When treated with PGE1 , TP,Al,CHO, TG, Pr/24h, ADP- induced PAG(5) ,and Adr- induced PAG(5) and PAG(m) were significantly different from those before treatment (P＜0.05). Adr- induced PAG(5) and PAG(m) were significantly different. Adr- induced PAG(5) was xsitively correlated with BUN and Scr in PNS(P＜0.01). Similar correlation was found between ADP-induced PAG(5) and Al ,BUN,Scr,Pr/24h(P＜0.05), AD- induced PAG(m) and TP,CHO(P＜0.05). Conclusions: PGE1 may be an effective drug for the treatment for hypercoagulation in patients with PNS.

Stress Relaxation and Sensitivity Weight for Bi-Directional Evolutionary Structural Optimization to Improve the Computational Efficiency and Stabilization on Stress-Based Topology Optimization

Stress-based topology optimization is one of the most concerns of structural optimization and receives much attention in a wide range of engineering designs.To solve the inherent issues of stress-based topology optimization,many schemes are added to the conventional bi-directional evolutionary structural optimization(BESO)method in the previous studies.However,these schemes degrade the generality of BESO and increase the computational cost.This study proposes an improved topology optimization method for the continuum structures considering stress minimization in the framework of the conventional BESO method.A global stress measure constructed by p-norm function is treated as the objective function.To stabilize the optimization process,both qp-relaxation and sensitivity weight scheme are introduced.Design variables are updated by the conventional BESO method.Several 2D and 3D examples are used to demonstrate the validity of the proposed method.The results show that the optimization process can be stabilized by qp-relaxation.The value of q and p are crucial to reasonable solutions.The proposed sensitivity weight scheme further stabilizes the optimization process and evenly distributes the stress field.The computational efficiency of the proposed method is higher than the previous methods because it keeps the generality of BESO and does not need additional schemes.

Effect of Yiqitongyanghuatan Recipe on Experimental Atherosclerosis in Rabbits

In order to investigate the roles of Yiqitongyanghuatan (YQTYHT) recipe in reducing the levels of serum cholesterol and plasma lipid peroxidation(LPO), platelet aggregation function (PAgF) and platelet adhesion function (PAdF), the area of atherosclerotic plague coverage in aorta and the thickness of plague, 32 male Japanese white rabbits were divided into 4 groups. The results showed that the YQTYHT recipe could significantly lower the levels of serum cholesterol and tryglyceride, plasma LPO, and PAgF and PadF. The area of atherosclerotic plague coverage in aorta and the thickness of plague in the YQTYHT fed rabbits were decreased as compared with that in the high cholesterol fed rabbits. The above roles might contribute to the main mechanism of YQTYHT against atherosclerosis.

NON-INTERIOR SMOOTHING ALGORITHM FOR FRICTIONAL CONTACT PROBLEMS

A new algorithm for solving the three-dimensional elastic contact problem with friction is presented. The algorithm is a non-interior smoothing algorithm based on an NCP-function. The parametric variational principle and parametric quadratic programming method were applied to the analysis of three-dimensional frictional contact problem. The solution of the contact problem was finally reduced to a linear complementarity problem, which was reformulated as a system of nonsmooth equations via an NCP-function. A smoothing approximation to the nonsmooth equations was given by the aggregate function. A Newton method was used to solve the resulting smoothing nonlinear equations. The algorithm presented is easy to understand and implement. The reliability and efficiency of this algorithm are demonstrated both by the numerical experiments of LCP in mathematical way and the examples of contact problems in mechanics.

Homotopy Continuation Method for Linear Complementarity Problems

It is well known that a linear complementarity problem (LCP) can be formulated as a system of nonsmooth equations F(x) = 0, where F is a map from Rninto itself. Using the aggregate function, we construct a smooth Newton homotopy H(x,t) = 0. Under certain assumptions, we prove the existence of a smooth path defined by the Newton homotopy which leads to a solution of the original problem, and study limiting properties of the homotopy path.

Solving frictional contact problems by two aggregate-function-based algorithms

Three dimensional frictional contact problems are formulated as linear complementarity problems based on the parametric variational principle. Two aggregate-functionbased algorithms for solving complementarity problems are proposed. One is called the self-adjusting interior point algorithm, the other is called the aggregate function smoothing algorithm. Numerical experiment shows the efficiency of the proposed two algorithms.

Controlling interstory drift ratio profiles via topology optimization strategies

An approach to control the profiles of interstory drift ratios along the height of building structures via topology optimization is proposed herein.The theoretical foundation of the proposed approach involves solving a min-max optimization problem to suppress the maximum interstory drift ratio among all stories.Two formulations are suggested:one inherits the bound formulation and the other utilizes a p-norm function to aggregate all individual interstory drift ratios.The proposed methodology can shape the interstory drift ratio profiles into inverted triangular or quadratic patterns because it realizes profile control using a group of shape weight coefficients.The proposed formulations are validated via a series of numerical examples.The disparity between the two formulations is clear.The optimization results show the optimal structural features for controlling the interstory drift ratios under different requirements.

Topology Optimization of Transient Thermo-elastic Structure Considering Regional Temperature Control

In this paper,a topology optimization model for transient thermo-elastic coupling problems is proposed.Based on the method of solid isotropic material with penalization,the coupled equations of transient thermomechanical field are established.In this model,the objective is to minimize the global structural compliance with volume and maximum temperature constraints during the working time.To efficiently restrict the maximum temperature of the transient thermo-elastic structure in time and spatial dimensions,the regional temperature control scheme is constructed using the aggregation function.The adjoint variable method is adopted to derive the sensitivity of objective function and constraints,and the design variables are updated through the method of moving asymptotes to obtain clear optimal topologies.The effects of the duration and magnitude of the thermal and structural loads on the optimization results are discussed through several numerical examples.

Topology optimization of transient problem with maximum dynamic response constraint using SOAR scheme

This paper proposes a novel method for the continuum topology optimization of transient vibration problem with maximum dynamic response constraint.An aggregated index in the form of an integral function is presented to cope with the maximum response constraint in the time domain.The density filter solid isotropic material with penalization method combined with threshold projection is developed.The sensitivities of the proposed index with respect to design variables are conducted.To reduce computational cost,the second-order Amoldi reduction(SOAR)scheme is employed in transient analysis.Influences of aggregate parameter,duration of loading period,interval time,and number of basis vectors in the SOAR scheme on the final designs are discussed through typical examples while unambiguous configuration can be achieved.Through comparison with the corresponding static response from the final designs,the optimized results clearly demonstrate that the transient effects cannot be ignored in structural topology optimization.

Error Bounds of Two Smoothing Approximations for Semi-infinite Minimax Problems

In the paper we investigate smoothing method for solving semi-infinite minimax problems. Not like most of the literature in semi-infinite minimax problems which are concerned with the continuous time version（i.e., the one dimensional semi-infinite minimax problems）, the primary focus of this paper is on multi- dimensional semi-infinite minimax problems. The global error bounds of two smoothing approximations for the objective function are given and compared. It is proved that the smoothing approximation given in this paper can provide a better error bound than the existing one in literature.