Does CEO pay dispersion matter in an emerging market? Evidence from China’s listed firms

This paper examines how the institutional features of emerging economies (i.e., government ownership, political connections, and market reform) influence CEO pay-dispersion incentives. Consistent with our expectation, we find that CEO pay dispersion generally provides a tournament incentive in China's emerging market, as it is positively associated with firm performance. In addition, tournament incentives are weaker where firms are controlled by the government and where the CEO is politically connected, but it became stronger after the China's split-share structure reforms. Further, we find that in state controlled firms the satisfaction gained by meeting multiple economic and social goals largely reduces the effectiveness of tournament incentives, while the managerial agency problems inherent in private firms might mitigate them.

Effect of elastic modulus and poisson's ratio on guided wave dispersion using transversely isotropic material modelling

Timber poles are commonly used for telecommunication and power distribution networks, wharves or jetties, piling or as a substructure of short span bridges. Most of the available techniques currently used for non-destructive testing (NDT) of timber structures are based on one-dimensional wave theory. If it is essential to detect small sized damage, it becomes necessary to consider guided wave (GW) propagation as the behaviour of different propagating modes cannot be represented by one-dimensional approximations. However, due to the orthotropic material properties of timber, the modelling of guided waves can be complex. No analytical solution can be found for plotting dispersion curves for orthotropic thick cylindrical waveguides even though very few literatures can be found on the theory of GW for anisotropic cylindrical waveguide. In addition, purely numerical approaches are available for solving these curves. In this paper, dispersion curves for orthotropic cylinders are computed using the scaled boundary finite element method (SBFEM) and compared with an isotropic material model to indicate the importance of considering timber as an anisotropic material. Moreover, some simplification is made on orthotropic behaviour of timber to make it transversely isotropic due to the fact that, analytical approaches for transversely isotropic cylinder are widely available in the literature. Also, the applicability of considering timber as a transversely isotropic material is discussed. As an orthotropic material, most material testing results of timber found in the literature include 9 elastic constants (three elastic moduli and six Poisson's ratios), hence it is essential to select the appropriate material properties for transversely isotropic material which includes only 5 elastic constants. Therefore, comparison between orthotropic and transversely isotropic material model is also presented in this article to reveal the effect of elastic moduli and Poisson's ratios on dispersion curves. Based on this study, some suggestions are proposed on selecting the parameters from an orthotropic model to transversely isotropic condition.

Carbon nanotube dispersion using Portland cement-compatible surfactants

Carbon nanotubes (CNTs) are among the strongest known materials. Their potential as nanoscale reinforcement for cementitious materials is significant, with some reported compressive strength increases in excess of 50%. However, there is a great deal of variability in the results obtained, with some researchers showing zero-to-marginal increases in mechanical properties. One major reason for this is the poor dispersion of CNTs within the cementitious matrix. Many different approaches have been employed to disperse the highly hydrophobic CNTs within water and cement paste, with varying degrees of success. This paper presents the results of dispersion trials undertaken on CNTs within neutral and alkaline aqueous solutions and assesses the relative performance of different surfactants to facilitate dispersion.

Dynamic price dispersion in Bertrand–Edgeworth competition

This paper studies a dynamic oligopoly model of price competition under demand uncertainty. Sellers are endowed with one unit of the good and compete by posting prices in every period. Buyers each demand one unit of the good and have a common reservation price. They have full information regarding the prices posted by each firm in the market; hence, search is costless. The number of buyers coming to the market in each period is random. Demand uncertainty is said to be high if there are at least two non-zero demand states that give a seller different option values of waiting to sell. Our model features a unique symmetric Markov perfect equilibrium in which price dispersion prevails if and only if the degree of demand uncertainty is high. Several testable theoretical implications on the distribution of market prices are derived.

Reducing the effect of wave dispersion in a timber pole based on transversely isotropic material modelling

Round timbers are used for telecommunication and power distribution networks, jetties, piles, short span bridges etc. To assess the condition of these cylindrical shape timber structures, bulk and elementary wave theory are usually used. Even though guided wave can represents the actual wave behaviour, a great deal complexity exists to model stress wave propagation within an orthotropic media, such as timber. In this paper, timber is modelled as transversely isotropic material without compromising the accuracy to a great extent. Dispersion curves and mode shapes are used to propose an experimental set up in terms of the input frequency and bandwidth of the signal, the orientation of the sensor and the distance between the sensors in order to reduce the effect of the dispersion in the output signal. Some example based on the simulated signal is also discussed to evaluate the proposed experimental set up.

Development of a sustained release solid dispersion using swellable polymer by melting method

PURPOSE: This study is to design a sustained release solid dispersion using swellable polymer by melting method. METHODS: Polyethylene glycol 6000 (PEG 6000) and hydroxypropyl methylcellulose 4000 (HPMC 4000) were used in solid dispersion for not only enhancing drug dissolution rate but also sustaining drug release. HPMC 4000 is a common swellable polymer in matrix sustained release dosage form, but could not be used in preparation of solid dispersion by melting method. However, the current study utilized the swelling capability of HPMC 4000 accompanied by the common carrier PEG 6000 in solid dispersion to accomplish the goal. RESULTS: While PEG 6000 acted as a releasing stimulant carrier and provided an environment to facilitate the swelling of HPMC 4000, this swellable polymer could act as a rate-controlling agent. This greatly assisted the dissolution enhancement by changing the crystalline structure of drug to more amorphous form and creating a molecular interaction. CONCLUSIONS: These results suggested that this useful technique can be applied in designing a sustained release solid dispersion with many advantages.

A transformation-based multivariate chart to monitor process dispersion

Multivariate monitoring techniques such as multivariate control charts are used to control the processes that contain more than one correlated characteristic. Although the majority of previous researches are focused on controlling only the mean vector of multivariate processes, little work has been performed to monitor the covariance matrix. In this research, a new method is presented to detect possible shifts in the covariance matrix of multivariate processes. The basis of the proposed method is to eliminate the correlation structure between the quality characteristics by transformation technique and then use an S chart for each variable. The performance of the proposed method is then compared to the ones from other existing methods and a real case is presented.