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In this study, we compare the pricing behavior between online branches of traditional retailers (OBTRs) and online‐only retailers (ORs). Focusing on branded electronics sold online, we find that no significant pricing differences between ORs and OBTRs, but ORs seem to price slightly higher than OBTRs both in terms of posted‐ and full‐prices online. This result seems unique in online retail markets, contrary to the observations in the online markets of books, CDs and DVDs. The evidence also shows that both types of online retailers do not change their prices frequently, but adjustment magnitudes are large.

This paper investigates prices of consumer electronics sold on the Web by both online‐only retailers (Dotcoms) and the online branches of multi‐channel retailers (MCRs). Surprisingly, it finds that Dotcoms charge higher price than MCRs, a conclusion contradictory to the results of most of empirical studies. Also finds that the electronics prices decreased over the period of study in general, dropping about 0.6 percent per week, and the prices of MCRs and Dotcoms went down with time at a similar speed. Further, the prices across MCRs are 35.3 percent more dispersed than the prices across the Dotcoms based on full prices, and 33.1 percent more dispersed based on percentage prices. However, results show that price dispersion moved up with time in general, with no significant difference in the speeds between MCRs and Dotcoms.

This study aims to develop a new method to treat the numerical singularity at the critical nodes of two skew coordinates, and optimize the leakage of micro herringbone grooved journal bearings (MHGJBs) with this method.

A side leakage numerical algorithm is proposed by using the skew meshes with a virtual node (SMVN) method to evaluate the effects of groove angle, bank/groove ratio, groove depth and groove number on load capacity, friction and side leakage of MHGJB.

The SMVN method is effective in treating the numerical singularity at the critical nodes of two skew coordinates. Besides, a group of optimized parameters of micro herringbone groove is obtained which can not only minimize the side leakage but also improve the load capacity and friction force.

A virtual node method was proposed, which can significantly improve the calculation accuracy in the side leakage model.

The study of heat transfer mechanisms is an area of great interest because of various applications that can be developed. Mathematically, these phenomena are usually represented by partial differential equations associated with initial and boundary conditions. In general, the resolution of these problems requires using numerical techniques through discretization of boundary and internal points of the domain considered, implying a high computational cost. As an alternative to reducing computational costs, various approaches based on meshless (or meshfree) methods have been evaluated in the literature. In this contribution, the purpose of this paper is to formulate and solve direct and inverse problems applied to Laplace’s equation (steady state and bi-dimensional) considering different geometries and regularization techniques. For this purpose, the method of fundamental solutions is associated to Tikhonov regularization or the singular value decomposition method for solving the direct problem and the differential Evolution algorithm is considered as an optimization tool for solving the inverse problem. From the obtained results, it was observed that using a regularization technique is very important for obtaining a reliable solution. Concerning the inverse problem, it was concluded that the results obtained by the proposed methodology were considered satisfactory, as even with different levels of noise, good estimates for design variables in proposed inverse problems were obtained.

In this contribution, the method of fundamental solution is used to solve inverse problems considering the Laplace equation.

In general, the proposed methodology was able to solve inverse problems considering different geometries.

The association between the differential evolution algorithm and the method of fundamental solutions is the major contribution.