基于共拣网络的货位优化方法

将社会网络和社区发现的思想引入物流中心仓库货位的优化。首先建立描述货物之间被共同拣选情况的自组织共拣网络;然后通过社区发现算法从共拣网络中识别那些在一次作业中可能会同时拣选的货物构成共拣品族:最后按共拣品族就近摆放的原则优化货位并将拣选频率较高的共拣品族置于距出货口较近的位置。     

The effects of resolution methods and industry stress on the loss on assets from bank failures

In this paper, we examine how the value of failed bank assets differs between two types of FDIC resolution methods: liquidation and private-sector reorganization. Our findings show that private-sector reorganizations do not deliver the expected cost-savings from 1986 to 1991, a period of industry distress. On a univariate basis, the net loss on assets is lower for a private-sector reorganization than for a liquidation in both a period of industry distress and of industry health. However, institutions with higher quality assets and higher franchise values are more likely to be resolved using a private-sector resolution. Once we control for this selection bias, we find that institutions that are resolved during periods of industry distress result in higher resolution costs than liquidation. During periods of industry health, private-sector resolutions are less costly than liquidations. We show that if a bank that failed during the post-crisis period instead failed during the crisis period, its net loss as a percent of assets would have been 3.232 percentage points higher. Given that the average net loss on assets ratio is 21.42 percent during our sample period from 1986 to 2007, the increase in costs is economically significant.     

Fire sales by euro area banks and funds: What is their asset price impact?

The assets under management of investment funds have soared in recent years, triggering a debate on their possible implications for financial stability. We contribute to this debate assessing the asset price impact of fire sales in a novel partial equilibrium model of euro area funds and banks calibrated over the period between 2008 and 2017. An initial shock to yields causes funds to sell assets to address investor redemptions, while both banks and funds sell assets to keep their leverage constant. These fire sales generate second-round price effects. We find that the potential losses due to the price impact of fire sales have decreased over time for the system. The contribution of funds to this impact is lower than that of banks. However, funds’ relative contribution has risen due to their increased assets under management and banks’ lower leverage and rebalancing towards loans. Should this trend continue, funds will become an increasingly important source of systemic risk.     

Impacts of land-cover change on the water flow regulation ecosystem service: Invasive alien plants,fire and their policy implications

Land and water resource issues typically fall under separate governance systems. For example, agricultural policy regulates land-cover change while water departments regulate water quality. However, land-use changes can directly affect water resources. Water flow regulation is a key service which is affected by changes in land-cover but its dynamics are poorly understood by most policy makers and land management organisations. We simulated and quantified the effects of plant invasions on land-cover, hydrological soil characteristics and catchment responsiveness on flow regulation using a hydrological model. The case study was located in the indigenous fynbos shrublands in South Africa. Fynbos requires fire to regenerate, has moderate biomass, occurs mostly in areas with a potential to erode and is prone to invasion by woody plant species, particularly trees. Invasions can affect flow regulation by changing community structure and function and increasing fuel loads. The greater fuel load increases fire intensity and severity which, in turn, changes the hydrological responses of catchments. Few studies have assessed the effects of invasion on hydrological responses but studies on plantations have recorded significant increases in soil water repellence following fire, resulting in increased overland flow similar to impacts of fires in invaded areas. Simulation of clear-felling of pines and different degrees of water repellency increased both the responsiveness of the catchment to rainfall and extreme rainfall events. The simulated fire effects were consistent with other studies of hydrological responses to fire. Our study indicates that invasions of pines and acacias in the study area could substantially increase the risk of flood damage even from moderate rainfall events, and highlights the importance of maintaining flow regulation capacity. New policy approaches are required which take account of the linkages and interactions between land-use choices, water resources and ecosystem services, and address them when considering governance arrangements.     

Forest management under fire risk when forest carbon sequestration has value

We develop a multiple forest use model to determine the optimal harvest date for a forest stand producing both timber and carbon benefits under a risk of fire. An empirical application is provided for a forest owner producing maritime pine in Southwest of France. Our results indicate that a higher risk of fire will decrease the optimal rotation period. On the contrary, higher carbon prices increase the optimal harvesting age. To investigate the contradictory effects of fire risk and carbon price on forest rotation, we identify the set of carbon prices and fire risks that lead to a given rotation age. We also show that forest owner's willingness to pay for a risk reduction can be substantial (37.33 euros by ha and by year to reduce the annual fire risk from 1.26% to 0.07%).     

移动IP穿越防火墙问题研究

通过IPSEC技术,把移动IP和防火墙联系到一起,利用IPSEC保护移动IP的安全性。防火墙体系结构是边界防火墙结合IPSEC安全网关,因此防火墙本身具有识别IPSEC数据包的功能,使具有IPSEC保护的移动IP数据可以安全地通过防火墙,而IPSEC本身是安全的协议,所以在移动IP穿越防火墙的同时,也可以保证家乡网络的安全性。     

各类火灾探测器原理分析及应用探讨

火灾探测器能在火灾发生初期,将燃烧物产生的烟雾、热量、火焰等物理量变成电信号传输到火灾报警控制器,是现代消防系统的核心部件。文章通过对各类火灾探测器的工作原理进行分析,并对其应用场合进行探讨,为火灾自动报警系统的设计、施工与运行维护提供参考依据。     

苏海图煤矿301副巷灭火工程设计方案

本文主要论述了因井下副巷内着火后,采用大巷施工钻孔打入副巷内再下套管注浆的方法。     

论城镇消防安全布局研究

目前中国的城镇发展迅速,极大的促进了我国经济建设和社会的全面发展。但是在城镇的消防基础设施方面还存在着很多的问题。因此本文结合城镇发展的现状,对城镇的消防安全进行合理的布局。     

生物样品中毒品检测的研究进展

毒品滥用已经成为当今日益严峻的全球问题,它给人们和社会带来了各种各样的严重危害,因此对生物样品中毒品物质的检测就变成当务之急。本文主要介绍了几种较为新颖的毒品检测技术,以及它们的研究进展。