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1.
The push for the use of e-bidding is on the increase. In many countries, e-bidding has become part of the public procurement reform. However, previous studies have reported the low uptake of e-bidding in the construction industry. This study develops a theoretical structural model representing the impact six latent variables on the willingness of construction organizations to participate in e-bidding. Data from a questionnaire survey of 64 respondents from clients, contractors, consultants, and suppliers organizations was used to analyze the model. The result of the data analysis suggests that perceived barriers, cost, the perceived benefits of e-bidding and security concerns are the factors influencing willingness participate in e-bidding with perceived barriers being the most significant influencing factor. The perception about the adequacy of the existing traditional paper-based tendering and the perception about the non-readiness of business partners are the underlying barriers that need to be addressed when introducing e-biding. This study also discovers that when the respondents concern about the cost of e-bidding is high, their reported willingness to participate in e-bidding is higher when the perceived benefits is high that when the perceived benefits is low. To enhance the participation of the industry in e-bidding, public sector and large private clients would need to take leadership by making bidder's capability for e-bidding and e-project management at all project phases a criteria in bid evaluation. E-bidding developers and promoters need to use test project cases to monitor, measure, and document the benefits of e-bidding. To disseminate the perceived benefits, promoters would need to work closely with industry professional associations to develop promotional programmes linked to continuous professional development (CPD) points. The analytical approach used in this study should assist other researchers who might wish to address a similar research problem under a similar data and model constraints.  相似文献   
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Effectiveness of any alternative dispute resolution (ADR) method depends on the national legal system to which it is subjected. In Singapore, the increasing growth in the use of ADR methods may be adduced to developments in the Singapore legal environment. This paper reviews the characteristics of the Singapore national legal system for arbitration. It examines how the legal system facilitates effective use of ADR. By its features, the Singapore national legal system ensures parties’ autonomy but deters parties from taking opportunistic advantage of the voluntary nature of ADR. It enables procedural flexibility, and confidentiality of arbitration proceedings. It insulates the arbitration process from intervention from the Singapore courts and from corruption; and it provides maximum judicial support in the arbitral process. Hence, it ensures that disputes can be brought to a conclusion within a reasonable amount of time, at a reasonable cost, as well as preserving business relationships. The Singapore legal system insures the integrity of arbitration and the independence of arbitrators and arbitral institutions by immunity provisions. In addition, the legal system enhances the use of mediation and conciliation in a sequential tier with arbitration by providing a time limit for mediation or conciliation to terminate should they fail to produce a mutually acceptable settlement. In Singapore, the court system is generally known to be efficient; hence, ADR faces the practical challenge of becoming lengthier than court proceedings. The continuing search for and use of expedited arbitration procedures by arbitral institutions such as the Singapore International Arbitration Centre should reduce this challenge. This paper provides useful information on how a national legal system may be designed to support the use of ADR methods and facilitate their effectiveness.  相似文献   
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Iron(III) complexes of dimethyldithiocarbamate and imidazolyl dithiocarbamate were synthesized and characterized by elemental analyses, FTIR, UV–VIS and the ligands by NMR spectroscopy. The complexes were thermolysed as single molecule precursors at 180°C to prepare octadecylamine (ODA) capped iron sulfide nanocrystals and iron sulfide-hydroxyethyl cellulose (HEC) composites. UV–VIS, PL, FTIR, P-XRD, HRTEM, FESEM and EDS were used to characterize the iron sulfide nanocrystals and corresponding HEC nanocomposites. XRD confirmed iron sulfide nanocrystal (NP1) from dimethyldithiocarbamate to be hexagonal pyrrhotite-5H, Fe9S10 crystalline phase while iron sulfide nanocrystals (NP2) from imidazolyl dithiocarbamate is in pyrrhotite, Fe11S12 crystalline phase. TEM images show that the iron sulfide nanocrystals have particle sizes in the range 24–32?nm for NP1 and 18–25?nm for NP2 iron sulfide nanocrystals. The optical band gaps of the iron sulfide nanocrystals obtained from Tauc plots are 3.83 and 4.16?eV for NP1 and NP2, respectively. IR spectra, FESEM surface morphology and EDS spectra of iron sulfide/HEC composites confirmed dispersion of the iron sulfide nanocrystals within the hydroxyethyl cellulose (HEC) matrix.  相似文献   
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Next generation wireless networks (NGWN) will be an integration of heterogeneous wireless access networks that will interwork over an IP‐based infrastructure. This all‐IP vision has led to the development of handover mechanisms to support seamless mobility for active network services among the different interworking wireless networks in order to ensure network access ubiquity in NGWN. These handover mechanisms need to ensure that mobile devices continue to receive ongoing communication without any noticeable disruption during handover events among the heterogeneous networks. This paper gives a qualitative and quantitative review of current handover approaches of IP mobility management protocols for NGWN with an objective to introduce a new way of further optimizing the handover performance. In particular, the paper focuses on handover approaches of mobile IPv6 (MIPv6) based mobility management protocols. Thus, the need, benefits, and limitations of these handover approaches are explored. Thereafter, dynamic handover coordination is introduced as a new viable solution that exploits the benefits and mitigates the limitations of these handover approaches hence improving handover performance in terms of handover delay, packet loss, and signaling overhead. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
6.
This study investigates the free convective flow of heat generating/absorbing fluid between vertical parallel porous plates due to periodic heating of the porous plates. The analysis is performed by considering fully developed flow and steady-periodic regime. The momentum and energy equations, which arise from the definition of velocity and temperature, are written in dimensionless form. Separating the temperature and velocity fields into steady and periodic parts, the resulting second order differential equations are solved to obtain the expressions for velocity, temperature, skin friction and the rate of heat transfer. The effects of various flow parameters such as the suction/injection (s), heat source/sink (δ), Strouhal (St) and Prandtl (Pr) numbers on the skin friction coefficient, rate of heat transfer, velocity and temperature profiles are discussed with the aid of line graphs and contour maps.  相似文献   
7.
This article studies the effect of transpiration on a fully developed natural convection MHD flow in a vertical annulus with heat generation/absorption. The governing coupled differential equations are solved by an estimated analytical method identified as the Adomian decomposition method with initial conditions and an appropriate initial guess condition. Furthermore, the effect of several parameters illustrating the flow phenomena is considered through graphs and the numerical computations are obtained and presented through tables. However, it is observed that there is a decrease in velocity due to the effect of the suction of fluid on the heated porous wall with concurrent injection. Also, heat generation parameter enhances the temperature of the fluid on both the isothermal and constant heat flux.  相似文献   
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In next generation wireless network (NGWN) where multiple radio access technologies (RAT) co‐exist, a joint call admission control (JCAC) algorithm is needed to make a RAT selection decision for each arriving call. RAT selection policy has a significant effect on the overall new call blocking probability in the network. We propose a heuristic RAT selection policy to minimize new call blocking probability in NGWN. The proposed JCAC scheme measures the arrival rate of each class of calls in the heterogeneous wireless network. Based of the measured values of the arrival rates and using linear programming technique, the JCAC scheme determines the RAT selection policy that minimizes overall call blocking probability in the heterogeneous wireless network. Using Markov decision process, we develop an analytical model for the JCAC scheme, and derive new call blocking probability, handoff call dropping probability (HCDP), and call incompletion probability (CIP). Performance of the proposed scheme is compared with the performance of other JCAC scheme. Simulation results show that the proposed scheme reduces new call blocking probability, HCDP, and CIP in the heterogeneous wireless network. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
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