Different effects of economic and structural performance indexes on model construction of structural topology optimization

The objective and constraint functions related to structural optimization designs are classified into economic and performance indexes in this paper.The influences of their different roles in model construction of structural topology optimization are also discussed.Furthermore,two structural topology optimization models,optimizing a performance index under the limitation of an economic index,represented by the minimum compliance with a volume constraint（MCVC）model,and optimizing an economic index under the limitation of a performance index,represented by the minimum weight with a displacement constraint（MWDC）model,are presented.Based on a comparison of numerical example results,the conclusions can be summarized as follows：（1）under the same external loading and displacement performance conditions,the results of the MWDC model are almost equal to those of the MCVC model;（2）the MWDC model overcomes the difficulties and shortcomings of the MCVC model;this makes the MWDC model more feasible in model construction;（3）constructing a model of minimizing an economic index under the limitations of performance indexes is better at meeting the needs of practical engineering problems and completely satisfies safety and economic requirements in mechanical engineering,which have remained unchanged since the early days of mechanical engineering.

Usefulness of myocardial performance index for assessing right ventricular function after percutaneous closure of atrial septal defect

Objective Assessment of right ventricular function in patients with atrial septal defect(ASD)is difficult.The Doppler myocardial performance index(MPI)may provide a method of assessing function in these patients.The purposes of this study were to evaluate the right ventricular function and its changes in patients with ASD after transcatheter closure of ASD.Methods MPI,defined as the sum of isovolumic relaxation time and isovolumic contraction time derived by ejection time,was measured from tricuspid inflow and right ventricular outflow;Doppler velocity profiles recorded during routine echocardiography.Twenty nine patients(13 men,16 women;mean age 25.28±12.69,range 6 to 57 years)were diagnosed to secundum ASD[the stretched diameters of ASD were from 9 To 36(24.91±7.98)mm],and had a successfully placed Amplatzer septal occluder(ASO)(the sizes of ASO were from 11 to 40 mm);there were 81 sex-matched,age-matched healthy people(control group 41men,40 women;mean age 29.02±14.22,range 4 to 45 years).MPI was measured again on 3 days and 1 month after closure of ASD.Change in the study group was assessed and compared to the control subjects with structurally normal hearts.A complete 2-dimensional and Doppler echocardiographic examination was performed in all study groups.Results 1)The isovolumic relaxation and isovolumic contraction times[respectively(77.59±14.39)ms vs(60.93±12.94)ms,P<0.0001;(28.28±10.88)ms vs(23.64±9.01)ms,P=0.027]were prolonged,and ejection time[(260.65±21.86)ms vs(271.85±21.92)ms,P=0.033]was shortened in patients with ASD compared with that in control subjects,resulting in a marked increase in the MPI(0.40±0.07 vs 0.31±0.05,P<0.0001)from normal values;2)by Pearson's correlations,the MPI had no correlation with heart rate and blood pressure in control subjects and patients with ASD,but it correlated positively with age in patients with ASD;3)by Pearson's correlations,the MPI correlated positively with the diameter of ASD and pulmonary artery pressure;4)after transcatheter closure of ASD,the MPI decreased markedly.Conclusions 1)MPI is a conceptually new,simple,and reproducible Doppler index in patients with ASD;2)MPI is free from the effect of age,heart rate and blood pressure;(3)MPI appears to be relatively dependent on changes in the diameter of ASD and pulmonary artery pressure;4)the right ventricular function was improved after transcatheter closure of ASD.

Performance index limits of high reinforced concrete shear wall components

The deformation performance index limits of high reinforced concrete （RC） shear wall components based on Chinese codes were discussed by the nonlinear finite element method. Two typical RC shear wall specimens in the previous work were first used to verify the correctness of the nonlinear finite element method. Then, the nonlinear finite element method was applied to study the deformability of a set of high RC shear wall components designed according to current Chinese codes and with shear span ratio λ≥2.0. Parametric studies were made on the influence of shear span ratio, axial compression ratio, ratio of flexural capacity to shear capacity and main flexural reinforcement ratio of confined botmdary members. Finally, the deformation performance index and its limits of high RC shear wall components under severe earthquakes were proposed by the finite element model results, which offers a reference in determining the performance status of RC shear wall components designed based on Chinese codes.

Constitution of Hamiltonian Function and Solution of Optimal Control of a Sort of Performance Index

Hamiltonian function is firstly constituted for solving optimal control. When character of controlled object is known,Hamiltonian function is determined by performance index. In this paper,by constituting Hamiltonian function and solving optimal control of a sort of performance index,we can understand optimal control theory and apply optimal control method better.

A“Three-index”Seismic Performance Evaluation Method Based on Sino-US Seismic Code

The Code for Seismic Design of Buildings(GB50011-2010)in 2016 and the method of seismic performance-based design for high-rise buildings in the Guide for Performance-based Design of High-Rise Buildings(TBI2017)are compared.In view of the characteristics and limitations of the seismic performance index set by the Sino-US seismic code,a“three-index”performance index system and evaluation process considering the displacement angle of the structural interlayer,the plastic damage degree of components and the plastic strain of material is put forward;combining the example of time-history analysis of a out-of-code high-rise building under the rare earthquakes is verified.The results show that the method of seismic performance evaluation by using deformation control index in Sino-US seismic code is relatively simple;however,both are lacking in the setting of specific components and the whole structure level respectively.The"three-index"system can comprehensively and quantitatively evaluate the seismic performance of out-of-code high-rise buildings.

Evaluating the lifetime performance index with the inverted exponentiated Rayleigh distribution based on censored sample

Lifetime performance index is a powerful and effective way to analyze whether a product achieves the specified standards.In this paper,we investigate the lifetime performance index for the inverted exponential Rayleigh distribution using progressive type II censored sample data.The censored sample is able to greatly save the cost of the experiment and speed up the experiment.We derive the estimation value of lifetime performance index using the maximum likelihood method,and conduct the hypothesis test.Based on extensive numerical simulation,the power function is utilized to assess effectiveness of hypothesis testing.The simulation results show that lifetime performance index is good for determining whether the lifetime of the product reaches the criterion.Finally,a practical dataset is provided to give a demonstration for the procedures of lifetime performance evaluation.

Statistical inference of the lifetime performance index for Lindley distribution under progressive first-failure censoring scheme applied to HPLC data

This paper is devoted to the construct of the maximum likelihood estimator of the life-time performance index based on first-failure progressive right type censored sample for Lindley distribution. Statistical inference for assessing the lifetime performance of the items is performed. Finally, two examples are given, one of them considers a real life application of blood samples from organ transplant recipient using the liquid chromatography （HPLC） data and the other is a simulated example to illustrate the proposed statistical procedure.

Assessing the lifetime performance index of weighted Lomax distribution based on progressive type-Ⅱ censoring scheme for bladder cancer

In this paper,Health-related quality of life has not been adequately measured in bladder cancer.A recently developed reliable and disease-specific quality of life instrument(Bladder Cancer Index,RCI)was used to measure.Progressive type Ⅱ censoring schemes have potential usefulness in practice where budget constraints in place or there is a necessity for the speedy test.To test the process capability,the lifetime performance index Cl is widely recommended for evaluating the performance of the producfs lifetime and evaluating the lifetime performance index GL for the three-parameter Weighted-Lomax distribution(WLx)under progressive type-II censoring sample for a lower specification limit(L).The statistical inference concerning CL is conducted via obtaining the maximum likelihood of Cl on the base of progressive type-II censoring.The asymptotic normal distribution of the MLE of CL and the confidence interval is proposed.Moreover,the hypothesis testing of CL for evaluating the lifetime performance of WLx data is conducted.Also,assuming the conjugate prior distribution and squared error loss function,this study constructs a Bayes estimator of CL.The Bayes estimator of CL is then utilized to develop a credible interval in the condition of known L.Moreover,we propose a Bayesian test to assess the lifetime performance of products.We also propose a Bayesian test to assess the lifetime performance of products.Finally,two examples are given,one of them is considering a real life data of the remission times of bladder cancer patients in endurance lifetime test and the other is a simulated example to illustrate the usage of the proposed procedure.

Extreme gradient boosting algorithm based urban daily traffic index prediction model:a case study of Beijing,China

The exhaust emissions and frequent traffic incidents caused by traffic congestion have affected the operation and development of urban transport systems.Monitoring and accurately forecasting urban traffic operation is a critical task to formulate pertinent strategies to alleviate traffic congestion.Compared with traditional short-time traffic prediction,this study proposes a machine learning algorithm-based traffic forecasting model for daily-level peak hour traffic operation status prediction by using abundant historical data of urban traffic performance index(TPI).The study also constructed a multi-dimensional influencing factor set to further investigate the relationship between different factors on the quality of road network operation,including day of week,time period,public holiday,car usage restriction policy,special events,etc.Based on long-term historical TPI data,this research proposed a daily dimensional road network TPI prediction model by using an extreme gradient boosting algorithm(XGBoost).The model validation results show that the model prediction accuracy can reach higher than 90%.Compared with other prediction models,including Bayesian Ridge,Linear Regression,ElatsicNet,SVR,the XGBoost model has a better performance,and proves its superiority in large high-dimensional data sets.The daily dimensional prediction model proposed in this paper has an important application value for predicting traffic status and improving the operation quality of urban road networks.

Measuring the social performance of forest management

Forests produce several types of benefits to both forest landowners and society.The social benefit of private forestry is equal to private benefit plus positive externalities minus negative externalities.This study developed alternative metrics for the evaluation of the social benefit of forest management.Forest management was assessed in terms of five criteria:economic,socio-cultural,environmental and ecological performance and the resilience of the forest ecosystem.Each criterion was described with three numerical indicators.Alternative performance indices were calculated from the indicator values using methods developed for multi-criteria decision making.It was concluded that indices based on the multiplicative Cobb-Douglas utility function might be the most recommendable when forestry should produce a balanced combination of different ecosystem services.When the indices were used to compare alternative silvicultural systems in terms of their social performance,continuous cover management was ranked better than even-aged management.The performance of even-aged management improved when it aimed at increasing the share of mixed stands and broadleaf species.Maximizing net present value(NPV) with a 1 % discount rate led to better social performance than maximizing NPV with a 4% discount rate.

Simultaneous quadratic performance stabilization for linear time-delay systems

A newly designed approach of simultaneous stabilization is given for linear discrete time-delay systems. The problem of stabilization for a collection of systems is discussed initially. Adequate condition are obtained in terms of linear matrix inequalities （LMIs） which are independent of time delays such that the resultant collection of discrete time-delay systems are stable with an upper bound of the quadratic performance index. Subsequently, controllers are designed such that the resultant closed-loop discrete time-delay systems are simultaneously stabilized with the upper bound of the quadratic performance index. Finally,a numerical example is given to illustrate the design method.

Study on the Evaluation Method of the Performances of Corporation

This paper studies the evaluation method of the performances of corporation that was set up by the Financial Ministry in 1999, and then analyzes the advantages and the problems of the method. Finally, this paper studies the theoretical method of the evaluation of the performances of corporation.

Research on Performance Measurement System of Knowledge Strategy for Firms

Knowledge has become the most important strategic resource of firms, and the competition among firms is more based on knowledge than before. To deal with this challenge, some firms are trying to develop knowledge strategies to direct their knowledge management activities, but current strategic performance measurement systems can＇t evaluate the performance of knowledge strategies appropriately. This article develops a performance measurement system for knowledge strategies based on Balanced Scorecard, and simulates the system with an improved Data Envelopment Analysis （DEA） model.

The Preliminary Study on the Performance Appraisement about the Logistics Network Organization

How the performance in the course of implementing the logistics network organization is, and how the benefit level is produced, are undoubtedly focuses that cooperative parties pay close attention to, and the key to the network organization, too. The research on the performance appraisement about the network organization is not only very necessary, but also very important. This paper describes the characteristics of the performance appraisement about the logistics network organization, and sets up the evaluation index through analyzing the principle of constituting the logistics network organization＇s performance index system.

Dynamic Analysis and Dimensional Synthesis of Easy-to-Protect Large-Load Robot for Extracting Fermented Grains

To improve the operation situation of difficulty and low efficiency in the extraction of fermented grains(FG),a high-load and large-workspace reclaiming robot for ceramic cylinder fermentation is designed,and a reclaiming effector is designed according to the operating characteristics.Firstly,the kinematics and singularity of the mechanism are analyzed.A multi-domain polar coordinate search method is proposed to obtain the workspace and the volume of the mechanism.Secondly,the dynamic modeling is completed and the example simulation is carried out.Thirdly,the motion-force transmission index of the mechanism is established.And based on the global transmissibility and the good-transmission workspace,the dimensional synthesis of the driving mechanism is completed by using the performance atlas-based method.Finally,aiming at the regular workspace size,stiffness and loading capacity,the Pareto optimal solution set of the executive mechanism dimension is obtained by using the multi-objective particle swarm optimization(MOPSO)algorithm.This paper can provide a theoretical basis for the optimal design and control of FG reclaiming robot.

Fuzzy Based Intelligent Monitoring of Critical Lines in the Restructured Power Market

Restructured electric market environment allows the power wheeling transactions between the power producers and customers to meet the growing load demand. This will lead to the possible of congestion in the transmission lines. The possible contingencies of power components further worsen the scenario. This paper describes the methodology for the identification of critical transmission line by computing the real power and reactive power performance indices. It also demonstrates the importance of fuzzy logic technique used to rank the transmission lines according to the severity and demonstrated on IEEE-30 bus system.

Effect of seismic retrofit of bridges on transportation networks

The objective of this research is to determine the effect earthquakes have on the performance of transportation network systems.To do this,bridge fragility curves,expressed as a function of peak ground acceleration(PGA)and peak ground velocity(PGV),were developed.Network damage was evaluated under the 1994 Northridge earthquake and scenario earthquakes.A probabilistic model was developed to determine the effect of repair of bridge damage on the improvement of the network performance as days passed after the event.As an example,the system performance degradation measured in terms of an index,'Drivers Delay,'is calculated for the Los Angeles area transportation system,and losses due to Drivers Delay with and without retrofit were estimated.

Dynamic cluster member selection method for multi-target tracking in wireless sensor network

Multi-target tracking(MTT) is a research hotspot of wireless sensor networks at present.A self-organized dynamic cluster task allocation scheme is used to implement collaborative task allocation for MTT in WSN and a special cluster member(CM) node selection method is put forward in the scheme.An energy efficiency model was proposed under consideration of both energy consumption and remaining energy balance in the network.A tracking accuracy model based on area-sum principle was also presented through analyzing the localization accuracy of triangulation.Then,the two models mentioned above were combined to establish dynamic cluster member selection model for MTT where a comprehensive performance index function was designed to guide the CM node selection.This selection was fulfilled using genetic algorithm.Simulation results show that this method keeps both energy efficiency and tracking quality in optimal state,and also indicate the validity of genetic algorithm in implementing CM node selection.

Optimal design theories of tuned mass dampers with nonlinear viscous damping

Optimal design theory for linear tuned mass dampers （TMD） has been thoroughly investigated, but is still under development for nonlinear TMDs. In this paper, optimization procedures in the time domain are proposed for design of a TMD with nonlinear viscous damping. A dynamic analysis of a structure implemented with a nonlinear TMD is conducted first. Optimum design parameters for the nonlinear TMD are searched using an optimization method to minimize the performance index. The feasibility of the proposed optimization method is illustrated numerically by using the Taipei 101 structure implemented with TMD. The sensitivity analysis shows that the performance index is less sensitive to the damping coefficient than to the frequency ratio. Time history analysis is conducted using the Taipei 101 structure implemented with different TMDs under wind excitation. For both linear and nonlinear TMDs, the comfort requirements for building occupants are satisfied as long as the TMD is properly designed. It was found that as the damping exponent increases, the relative displacement of the TMD decreases but the damping force increases.

Energy Optimization of the Fin/Rudder Roll Stabilization System Based on the Multi-objective Genetic Algorithm （MOGA）

Energy optimization is one of the key problems for ship roll reduction systems in the last decade. According to the nonlinear characteristics of ship motion, the four degrees of freedom nonlinear model of Fin/Rudder roll stabilization can be established. This paper analyzes energy consumption caused by overcoming the resistance and the yaw, which is added to the fin/rudder roll stabilization system as new performance index. In order to achieve the purpose of the roll reduction, ship course keeping and energy optimization, the self-tuning PID controller based on the multi-objective genetic algorithm （MOGA） method is used to optimize performance index. In addition, random weight coefficient is adopted to build a multi-objective genetic algorithm optimization model. The objective function is improved so that the objective function can be normalized to a constant level. Simulation results showed that the control method based on MOGA, compared with the traditional control method, not only improves the efficiency of roll stabilization and yaw control precision, but also optimizes the energy of the system. The proposed methodology can get a better performance at different sea states.