http://hdl.handle.net/10397/69 Search the Channel search http://repository.lib.polyu.edu.hk/jspui/simple-search http://hdl.handle.net/10397/5417 Title: Implicit Mann approximation with perturbations for nonexpansive semigroups in CAT(0) spaces<br/><br/>Authors: Li, Xue-song; Yip, T. L.<br/><br/>Abstract: In this paper, we study the convergence of implicit Mann iteration processes with bounded perturbations for approximating a common fixed point of nonexpansive semigroup in CAT(0) spaces. We obtain the Δ-convergence results of implicit Mann iteration schemes with bounded perturbations for a family of nonexpansive mappings in CAT(0) spaces. Under certain and different conditions, we also get the strong convergence theorems of implicit Mann iteration schemes with bounded perturbations for nonexpansive semigroups in CAT(0) spaces. The results presented in this paper extend and enrich the existing literature.; MSC: 47H05; 47H10; 47J25<br/><br/>Description: DOI: 10.1186/1687-1812-2012-145 Tue, 11 Sep 2012 00:00:00 GMT http://hdl.handle.net/10397/5384 Title: Markovian iterative method for degree distributions of growing networks<br/><br/>Authors: Shi, Dinghua; Zhou, Huijie; Liu, Liming<br/><br/>Abstract: Currently, simulation is usually used to estimate network degree distribution P(k) and to examine if a network model predicts a scale-free network when an analytical formula does not exist. An alternative Markovian chain-based numerical method was proposed by Shi et al. Phys. Rev. E 71 036140 (2005) to compute time-dependent degree distribution P(k,t). Although the numerical results demonstrate a quick convergence of P(k,t) to P(k) for the Barabási-Albert model, the crucial issue on the rate of convergence has not been addressed formally. In this paper, we propose a simpler Markovian iterative method to compute P(k,t) for a class of growing network models. We also provide an upper bound estimation of the error of using P(k,t) to represent P(k) for sufficiently large t, and we show that with the iterative method, the rate of convergence of P(k,t) is root linear.<br/><br/>Description: DOI: 10.1103/PhysRevE.82.031105 Wed, 01 Sep 2010 00:00:00 GMT http://hdl.handle.net/10397/5248 Title: A directional relationship between freight and newbuilding markets: a panel analysis<br/><br/>Authors: Xu, Jane Jing; Yip, T. L.; Liu, Liming<br/><br/>Abstract: This article examines the dynamic relationship between international sea freight rate and newbuilding price by employing panel cointegration testing and estimating techniques. The primary question this article addresses is whether the goods (new ships) price and service (sea freight) rate lead or lag one another in a Granger-cause sense, or simultaneously move together. Monthly panel data on three different bulk shipping market segments over the period 1998–2009 are exploited in empirical analysis. Various panel unit root tests demonstrate that the data variables are integrated with unit roots, whereas panel cointegration techniques are used to estimate the dynamic relationship. A positive directional relationship from freight rate to newbuilding price is found, and freight rate is more sensitive to market changes than newbuilding price. These results indicate that investment in new ships is encouraged by a strong freight market.<br/><br/>Description: DOI: 10.1057/mel.2010.20 Tue, 01 Mar 2011 00:00:00 GMT http://hdl.handle.net/10397/5074 Title: Flag choice behaviour in the world merchant fleet<br/><br/>Authors: Luo, Meifeng; Fan, Lixian; Li, K. X.<br/><br/>Abstract: Flag selection is not just a crucial decision with regard to ship operation, but also plays an important role in national and international maritime policy. This study uses individual ship registration data to analyse flag selection behaviour, including flagging out decision using a binary choice model, and final flag choice by applying a nested logit model. Operators from traditional maritime countries are found to flag out high-quality vessels, whereas those from open-registry countries tend to flag out low-quality ones. Flag preferences are more sensitive to the registration fee than to the annual due; full-open flags are more elastic than quasi-open ones and substitution among flags within the same group is higher than across different groups. Port State Control, Flag State Control and safety records have opposite impacts on flag choice for ships from closed registry countries and those from open registers.<br/><br/>Description: DOI: 10.1080/18128602.2011.594969 Thu, 09 Jun 2011 00:00:00 GMT