Determinants of the future level of use of electronic marketplaces: The case of Canadian firms

Based on the literature dealing with the diffusion of innovation and with information systems, and building on the emerging concepts in electronic commerce (e-commerce), this paper aims at assessing the influence of various factors on firms’ future level of use of electronic marketplaces (e-marketplaces). This theoretical model is tested on data collected from 1,200 senior managers in Canadian firms. Findings indicate that a firm’s past experience in e-commerce, as well as the factors relating to its business relationships ultimately affect its future use of e-marketplaces. Results of TOBIT regressions also show that the complexity of sophisticated e-commerce implementations is negatively correlated with the future level of use of e-marketplaces, and that consultants and other experts play an essential role in encouraging and facilitating the use of this new type of electronic platform. Finally, our survey data demonstrate that the relative influence of some determinants differs according to the firms’ size. Pierre Hadaya is an assistant professor of MIS at the Faculté d’administration of the Université de Sherbrooke (Canada). He holds a Ph.D. in Management of Technology from the école Polytechnique de Montréal. His research interests lie at the intersection of information technology management, business strategy and interorganizational design.     

龙滩碾压混凝土重力坝快速施工技术

连续、高强度、快速施工既是碾压混凝土坝的施工特点,也是层间结合质量的根本保证。龙滩水电站碾压混凝土浇筑采用了合理的入仓手段和机械设备配置,通过配套的碾压混凝土施工技术的应用和健全的管理体系,有效地提高了碾压混凝土施工强度,保证了施工进度和施工质量。     

波流环境中污染物混合的分析

本文根据垂向二维数值模型计算求解和分析了波流环境中的一维对流扩散方程中的混合系数。此二维数值模型采用非线性k-ε紊流模型封闭雷诺时均方程，应用VOF方法处理自由面。分析方法是用该二维模型计算波流环境中污染物瞬时源产生的浓度场，计算该浓度场的断面平均浓度，求此断面平均浓度的概率分布，由概率分布的方差随时间的导数得到一维对流扩散问题中的混合系数。通过算例分析，发现波流环境混合系数随着波浪周期和波 高的不同，可能大于纯流和纯波的混合系数之和，也可能比纯流情况下小；波周期与混合系数呈正比。且存在一个使混合系数最大的波高。     

Fixed collision rate back-off scheme for collision resolution in wireless networks

This investigation proposes a fixed collision rate (FCR) back-off algorithm for wireless networks. The proposed scheme takes advantage of the central unit (CU) in a wireless network to broadcast a common back-off window size to all the users, significantly alleviating the unfairness of bandwidth utilization in conventional binary exponential back-off (BEB) algorithms. It is shown that, when maximum throughput is achieved, collision rate is almost a constant for any traffic load. In the operation of the FCR, the CU dynamically adjusts the back-off window size to keep the collision rate at a constant level for maximum throughput. Simulation results demonstrate that the unfairness of bandwidth utilization in the BEB is significantly lessened and the throughput can be maintained at e^-1≈0.368 when the number of users approaches infinity. The capture effect even further improves system performance.     

基于物元模型的警务信息化集成风险评价

警务信息化建设已经开始进入信息与系统集成的阶段,公安机关在此过程中面临着多种集成风险。分析警务信息化集成的背景与肯面临的各种风险,应用物元模型建立警务信息化集成风险的评价的指标体系与方法,给出相应的计算示例。结果表明该方法有效可行,为警务信息化集成风险评价提供一条新途径。     

建设工程项目招投标规范化可拓综合评判

为了客观、准确地对招投标的规范化进行评判，依据《中华人民共和国招标投标法》选取公开、公平、公正和诚实信用四大指标为招投标规范化的评判特征因子。在此基础上，引入可拓学理论，建立了招投标规范化评判物元模型，给出了基于关联函数的可拓评判方法。并结合某招投标活动，实际评判了其规范化综合水平。     

Review of Forms of feeling: The heart of psychotherapy.

Reviews the book, Forms of feeling: The heart of psychotherapy by Robert F. Hobson. Robert Hobson calls this book his autobiography as a therapist. As such it provides interesting glimpses into some of his more meaningful sessions with clients, illuminating his approach to therapy and enabling the reader to see a master therapist at work. Hobson also presents a new method of therapy, which he calls the conversational model. On this level, his book is considerably less satisfying. Hobson succinctly outlines the general principles of the conversational model and basic skills required of the therapist, but in so doing offers essentially little new information, however valid the points may be. According to Hobson, the conversational model is designed for clients whose problems arise from disturbances in their significant relationships, and those problems are best solved not by talking about them but by being in a relationship such as therapy that provides "a special kind of friendship." Hobson puts great stress on the use of metaphorical language in therapy and learning how to use the language of art as well as of science. He relies heavily on literary quotations, prefacing each section with one or two, and liberally interspersing many more within the pages of text. The net result is not so much illuminating as it is wearisome, and the general tone is slightly pretentious and, when Hobson addresses his "dear Reader" directly, somewhat condescending. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Residual Stress Simulation of Injection Molding

In this study, distribution and history of residual stresses in plaque-like geometries are simulated based on linear thermoviscoelastic model, which helps to understand the mechanics and evolution of the residual stresses in the injection molding process. The numerical calculation of direction, combined with the specified boundary conditions. Results show that the stress variation across the thickness exhibits a high surface tensile value changing to a compressive peak value close to the surface, with the core region experiencing a parabolic tensile peak. Residual stress distribution throughout the thickness is almost same along the flowpath and the final residual stresses value near the gate is lower than the value near the end of flowpath.     

国内外微生物采油技术综述

生物技术特别是微生物采油技术，已经引起了石油工程技术人员的空前关注，目前在国内外开展的微生物采油先导性矿场试验已初见成效，较为典型的当数美国和俄罗斯，我国的吉林、胜利等油田也进行了矿场试验，增油效果令人鼓舞。同时，随着科学技术的发展，一些先进的微生物学研究工具已经进入微生物采油技术的研究领域，如分子生物学、示踪剂及可视化技术等已经成为微生物采油机理研究的重要工具。相关的石油烃降解理论以及建立数学模型等也取得了系列成果。微生物采油的应用也从过去的单井处理逐渐向整个区块或油田发展，并见到了明显效果。     

A Multinomial Model of Event-Based Prospective Memory.

Prospective memory is remembering to perform an action in the future. The authors introduce the 1st formal model of event-based prospective memory, namely, a multinomial model that includes 2 separate parameters related to prospective memory processes. The 1st measures preparatory attentional processes, and the 2nd measures retrospective memory processes. The model was validated in 4 experiments. Manipulations of instructions to place importance on either the prospective memory task or the background task (Experiments 1 and 2) and manipulations of distinctiveness of prospective memory targets (Experiment 2) had expected effects on model parameters, as did a manipulation of the difficulty of prospective memory target encoding (Experiments 3 and 4). An alternative model was also evaluated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)