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The purpose of this paper is to design a simple and accurate a-posteriori Lagrangian-based error estimator is developed for the class of backward differentiation formula (BDF) algorithms with variable time step size, and the adaptive time-stepping in BDF algorithms is demonstrated for efficient time-dependent simulations in fluid flow and heat transfer.

The Lagrange interpolation polynomial is used to predict the time derivative, and then the accurate primary result is obtained by the Gauss integral, which is applied to evaluate the local error. Not only the generalized formula of the proposed error estimator is presented but also the specific expression for the widely applied BDF1/2/3 is illustrated. Two essential executable MATLAB functions to implement the proposed error estimator are appended for practical applications. Then, the adaptive time-stepping is demonstrated based on the newly proposed error estimator for BDF algorithms.

The validation tests show that the newly proposed error estimator is accurate such that the effectivity index is always close to unity for both linear and nonlinear problems, and it avoids under/overestimation of the exact local error. The applications for fluid dynamics and coupled fluid flow and heat transfer problems depict the advantage of adaptive time-stepping based on the proposed error estimator for time-dependent simulations.

In contrast to existing error estimators for BDF algorithms, the present work is more accurate for the local error estimation, and it can be readily extended to practical applications in engineering with a few changes to existing codes, contributing to efficient time-dependent simulations in fluid flow and heat transfer.

The purpose of this study is to forecast the development performance of important economies in a smart city using mixed-frequency data.

This study introduces reverse unrestricted mixed-data sampling (RUMIDAS) to support vector regression (SVR) to develop a novel RUMIDAS-SVR model. The RUMIDAS-SVR model was estimated using a quadratic programming problem. The authors then use the novel RUMIDAS-SVR model to forecast the development performance of all high-tech listed companies, an important sector of the economy reflecting the potential and dynamism of urban economic development in Shanghai using the mixed-frequency consumer price index (CPI) producer price index (PPI), and consumer confidence index (CCI) as predictors.

The empirical results show that the established RUMIDAS-SVR is superior to the competing models with regard to mean absolute error (MAE) and root-mean-squared error (RMSE) and multi-source macroeconomic predictors contribute to the development performance forecast of important economies.

Smart city policy makers should create a favourable macroeconomic environment, such as controlling inflation or stabilising prices for companies within the city, and companies within the important city economic sectors should take initiative to shoulder their responsibility to support the construction of the smart city.

This study contributes to smart city monitoring by proposing and developing a new model, RUMIDAS-SVR, to help the construction of smart cities. It also empirically provides strategic insights for smart city stakeholders.

The purpose of this study is to investigate the effects of stud height, stud diameter, ultimate stress of stud and concrete strength on the static behaviour of studs in push-off tests based on the ductile fracture theory.

Push-off tests of headed stud shear connectors with different heights and diameters used in concrete of various strengths were designed and implemented. A finite element model was established based on a ductile fracture criterion of ML15 cold-heading steel with stress triaxiality and Lode angle parameter. Based on the results of the parametric study of the numerical model, equations were proposed to evaluate the effect of stud height h_s, stud area A_s, concrete strength f_c and stud ultimate strength f_su used in concrete of various strengths on the static behaviour of studs.

The typical failure phenomenon observed among the test specimens was the fracture of the shank of studs. The microscopic images of the stud fracture surfaces and the verified finite element model indicate that the studs were fractured as a result of the combined action of tension and shear.

A new method for calculating ultimate load P_u and ultimate slip S_u is proposed in this paper. In the method, P_u is linearly related to f_su^0.2143, A_s^0.7790, h_s^0.0974, f_c^0.2065. S_u is linearly related to f_su^1.078, A_s^0.4681, h_s^(−0.3135), f_c^(−0.3480).

The purpose of this paper is to summarize the China Agricultural Economic Review (CAER)'s second annual conference, which was organized by the CAER editorial office and International Food Policy Research Institute (IFPRI).

The conference theme was “Agriculture and the Wealth of Nations”, aiming to explore the importance of agriculture as well as the relationship and interaction between agriculture and the whole economy. The attendees from 14 countries discussed the related issues, and a number of distinguished scholars and policy makers were also invited to present at the conference. This summary presents the topics covered at the conference and highlights discussion points.

Action items were identified which could be appropriately organized into the following sections: agricultural trade and rural labor issues; rural governance and public policy; climate change and food security; rural land and rural finance issues.

The paper illustrates how the academic platform established by the CAER‐IFPRI conference, enables scholars from varied cultures and fields to get together to share their researches and ideas.

The purpose of this paper is to provide readers with the main findings and conclusions of papers presented at the 2011 CAER‐IFPRI International Conference held under the theme “Is China entering a high food price era?”

The authors conduct a desk review of papers presented at the conference and provide a brief summary of the analytical tools, and main findings and conclusions of each presentation.

These reviews show that, while there seems to be an increase in the prices of agricultural commodities on the Chinese market, in real terms, these rises fall far below the increases in the prices of industrial commodities. Thus, expert views remain divided on whether China is entering an era of high food price.

The discussions initiated by the conference theme aroused researchers' curiosities for further studies into understanding the current level of food prices in China.

The purpose of this paper is to examine the financing and provision of basic public services in China. The main issue addressed is how to reform the public finance system to achieve quality and fairness in the provision of basic public services.

Based on an historical analysis of the functional transformation of the public finance system in China and on an empirical analysis of the current public finance system and the public service provision system, a comprehensive understanding was gained about the relationship between the financing and provision of basic public services.

The paper argues that there is a close relationship between the provision of basic public services and the functional changes made to the public finance system. Based on a systematic retrospective study of the Chinese Government’s efforts to improve basic public services over the last three decades, this paper offers policy suggestions on further public finance restructuring that would support better service provision.

By analyzing issues in the public service provision system, this paper contributes to the debate about the efficiency improvement made to governmental functions in China.