Sizing parking facilities at airports

Established rules-of-thumb and industry guidelines for estimating the supply of parking at airports are based on uncertain quantities such as design year enplanements and number of airport employees, and are independent of cost. In the presence of continued uncertainty and increasing competition for limited space in and around airports, it is important that facilities are sized in relation to cost of providing and using them. A probabilistic model based on the classical “newsboy” problem is proposed to determine the optimal supply of parking in relation to expected total cost while treating demand as a random quantity. Empirical data are used to demonstrate the application of the proposed model for decision making. In addition to construction and maintenance costs, and user costs, decisions are shown to be sensitive to the level of uncertainty of design year enplanements.     

Port competition between Shanghai and Ningbo

The objective of this paper is to analyse the relative competitiveness of the neighbouring container ports of Shanghai and Ningbo in China and to develop a view of the likely future outcome of the competition between them. After assessing the demand for their services within what is hypothesized as a shared hinterland, current supply and future expansion plans are detailed and considered within the two ports' wider development strategies. The relative competitiveness of the two ports is then evaluated on the basis of price and quality of service, as embodied within the concept of generalized cost as incurred by customers. A critical political dimension is a necessary element of this analysis. It is concluded that continued economic development in the hinterland, central government policies on regional development and China's accession to the World Trade Organization (WTO) will all contribute to growing demand for port services. However, Ningbo will continue to gain greater market share as the result of advantages in its natural endowments (particularly depth of water), price (especially in terms of recovering the cost of capacity expansions) and quality of service improvements that are predicted to emerge as the result of currently planned enhancements to inland transport infrastructure and logistical systems.     

汽车消费信贷发展的策略研究

随着我国汽车产业的发展，汽车消费信贷已经越来越得到人们的认同。文章结合研究美国与日本汽车消费信贷的发展状况，提出了目前我国汽车消费信贷业存在的问题，并给出一些发展对策。     

大坡度斜井断面测量

介绍海南某工程大坡度斜井净空断面测量方法。通过数据采集,进行坐标转换,能够方便地计算出测点超欠挖。现场测量表明:该方法经济实用,能达到事半功倍的效果。     

火与气的探查测绘

火与气的探测系统在许多现场扮演着安全方面极重要的角色。正规的安全评估常常假设火与气的探测系统可以减轻危险，然而在这方面却几乎没有标准的指导原则。要想对有关参数定量往往是很困难的，而想要确定在安全要求方面的预期性状或表述已达到的实际性状也往往无章可循。[第一段]     

VoIP语音评价方法综述

通过对VoIP技术的阐述，说明了VoIP语音技术的不完善；分析和比较了几种VoIP语音评价方法，希望通过对这些语音评价方法的思考，能够为语音质量的提高有所帮助。     

Autonomy, bureaucracy, professionalism and accountability: a transaction cost approach to shipboard controls

In recent years, shipping industry has encountered severe competition, technological change, and environmental and safety concerns. In order to remain competitive, firms need to review and redesign shipboard work. A crucial aspect of these efforts is shipboard controls that define the extent of autonomy and accountability of officers and crew. This study examines four types of controls on board ships. These are monitoring and autonomy, outcome accountability, formalization and professionalization. The study applied trancsaction cost theory to test eight hypotheses on board 16 ships in two companies. The results largely confirm theoretical predictions. Task visibility, complexity and uncertainty show strong relationships to the four types of controls. However, there are also significant gaps in that accountability for outcomes is low, and situation with regard to crew training and autonomy can be improved. Implications for human resource practice and future research are discussed.     

Dissolved organic matter studies in enclosed systems: Application of Hydrophobic fractionation for the assessment of organic nitrogen dynamics

The evolution of dissolved organic matter (DOM) in a non-axenic batch culture of the marine diatom Thalassiosira tumida was studied by hydrophobic fractionation during a three month experiment. DOM was fractionated with XAD-2 resin into hydrophobic (acid and neutral, “humic”) and hydrophilic fractions. The combined amino acid contents of unfractionated filtered seawater, XAD-fractions and particulate material were determined during the growth, stationary and degradation phases of the culture, and variations related to changes in dissolved organic nitrogen (DON) in XAD-fractions, dissolved inorganic nitrogen, algal and bacterial biomass. XAD-fractionation enabled the discrimination of simultaneously ocurring release and uptake of organic nitrogenous compounds: During the diatom growth there was a net increase of tolal DON concentrations, which was mostly accounted for by the hydrophilic fraction. A concurrent heterotrophic uptake of combined amino acids and other non-amino acid organic nitrogen was discernible by the decrease of their concentrations in the hydrophobic fractions. In the stationary phase, during the prevailing net consumption of total DON, the production of algal exudates could be detected in the hydrophobic fractions, while uptake mainly involved non-amino acid organic nitrogen from the hydrophilic fraction. During the degradation phase, after two months part of the particulate amino acid pool was transformed into hydrophilic DON, which in contrast to the stationary phase, was not adequate for supporting sustained bacterial growth. This suggests that the generation of recalcitrant substances may begin in the hydrophilic fraction of DOM. A slight increase of the hydrophobic acid fraction was indicative of the incipient formation of humic substances. XAD-2 was able to adsorb substances from fast changing DOM pools and thus should be a useful tool in studies concerned with phytoplankton and bacterial dynamics.     

用多层次多目标决策法进行施组设计方案选优

通过对影响铁路施工组织方案因素的分析,介绍了应用多层次多目标决策方法进行铁路施工组织设计方案选优的步骤和内容,并给出了相应的算法.