柴油机绿色设计与制造技术

从绿色设计的要求出发 ,分析探讨了与柴油机绿色设计与制造有关的几个问题 ,介绍了降低柴油机环境污染提高其环境友好度的各种措施及方法     

非饱和土体气态水迁移引起的含水量变化方程

基于现有土力学理论及流体力学理论 ,结合非饱和土气态水迁移特征 ,得到了根据土体基质吸力和温度确定土孔隙饱和蒸气压力的表述关系式 ,推导得到非饱和土体中气态水迁移引起含水量变化的非稳态方程 ,方程揭示了气态水迁移的动力是温度梯度和含水量梯度 ,气态水迁移现象是温度不均匀分布和含水量不均匀分布单独或共同作用的表现形式 ,方程表述了实验揭示的现象。最后应用含水量变化方程对实验结果进行了计算分析 ,验证了该方程的合理性     

企业核心能力理论发展评述

企业核心能力理论是当今世界管理学和经济学交互融合的最新理论成果之一。长期以来理论界和工商实践一直在寻求企业持续竞争优势的奥秘。企业核心能力理论则揭示了在企业表象及所处环境之外的能使企业获得优势的内在特质。本论述了企业核心能力理论的发展历程、形成背景、时代特征和主要论点。     

The multi‐actor,multi‐criteria analysis methodology (MAMCA) for the evaluation of transport projects: Theory and practice

In this paper the multi‐actor multi‐criteria analysis (MAMCA) method to evaluate transport projects is presented. This evaluation method specifically focuses on the inclusion of qualitative as well as quantitative criteria with their relative importance, defined by the multiple stakeholders, into one comprehensive evaluation process in order to facilitate the decision making process by the different stakeholders. The MAMCA methodology is introduced by an overview of other evaluation methods for transport projects in the past and is illustrated by means of two practical cases. The introduction will lead us to the theoretical conception of the MAMCA method where we draw the attention to the proven usefulness of the MAMCA for the evaluation of transport projects and the inclusion of different kinds of stakeholders, individuals as well as groups, into the evaluation process.     

宜巴高速公路界岭隧道横洞进正洞挑顶施工方案比选

宜巴高速公路界岭隧道施工中,由于复杂的地质状况和处理坍塌历时过长,整个隧道工程严重滞后建设项目工期。因此,决定增设横洞,从横洞向正洞掘进,增加主洞工作面,以满足项目建设进度要求。文章详细介绍了增设横洞两种方案的施工工艺,在技术可行、经济合理基础上,针对界岭隧道横洞垂直贯穿进入正洞和曲线渐变过渡施工转入正洞的施工方案进行了分析对比。     

Adapting to Catch Shares: Perspectives of West Coast Groundfish Trawl Participants

Abstract

Catch share programs are used in fisheries management to meet goals such as species recovery, overcapacity reduction, and economic efficiency. Anticipated impacts include fleet consolidation, infrastructure reduction, and social disruption within communities. The Pacific Coast Groundfish Fishery Social Study (PCGFSS) aims to understand social changes related to the recently implemented West Coast Groundfish Trawl Catch Share Program. In this article, we use a subset of PCGFSS data to explore the ways remaining fishery participants have thus far adapted to catch shares. While some vessels have left the fishery, we found that many participants are adapting to this catch shares program despite challenges. Quota leasing strategies, fishery diversification, gear innovation, and community quota funds are some of the tools participants are using to continue operating under the catch shares program. These early challenges and adaptations to the catch share program are worthy of continued tracking, as researchers, managers, and fishing communities, would benefit by considering first-hand perspectives of the on-the-ground realities of harvesting groundfish in the rationalized fishery.     

About attitudes and perceptions: finding the proper way to consider latent variables in discrete choice models

We provide an in-depth theoretical discussion about the differences between individual-specific latent constructs (representing attitudes, for example, but also other characteristics such as values or personality traits) and alternative-specific latent constructs (that may represent perceptions) affecting the choice-making process of individuals; we also carry out an empirical exercise to analyze their effects. This discussion is of importance, as the majority of papers considering attitudinal latent variables just take these as attributes affecting directly the utility of a certain alternative, while systematic taste variations are rarely considered and perceptions are mostly ignored. The results of our case study show that perceptions may indeed affect the decision making process and that they are able to capture a significant part of the variability that is normally explained by alternative specific constants. Furthermore, our results indicate that attitudes may be a reason for systematic taste variations, and that a proper categorization of latent variables, in accordance with underlying theory, may outperform the customary assumption of linearity.     

Strategic beliefs of port authorities

Over the last decade, insights from the strategic management discipline have increasingly been applied to ports. A review of literature shows that in the analysis of port authority strategy, mainly outside-in approaches are applied. This paper adds to the emerging understanding of the port authority’s strategy by applying a cognitive perspective. Specifically, the strategic cognition of firms’ executives is one of the explanatory variables behind firms’ strategic decisions. Furthermore, cognitions are influenced by the organisational contexts in which port authority executives have worked. As a result, managerial “mental maps’ may vary across industry contexts and over time. This research investigates the strategic cognition of a global set of port authority executives through a survey-based instrument. The results show that, to a large extent, PAs resemble “regular” for-profit companies, but that they possess some specific beliefs that distinguish them from “regular” companies.     

Are we doing it wrong or do we expect too much? Forces that push authorities to become public transport designers

This paper presents a number of reasons that are responsible for the disappointment of authorities in their operators’ efforts to develop public transport (PT) to the advantage of their travellers. The lessons drawn in this paper are based upon the competitive tendering experience of the authors and upon the results of meetings organised with parties involved in competitive tendering and aimed at exchanging lessons. There appears to be three main causes: (1) there is freedom for the operator, but the contract is bad; (2) there is freedom for the operator, there is a good contract, but there is no market; and (3) there is freedom for the operator, but the operator is not able to use it. The paper concludes with a few perspectives for improvement.