微利时代下的铜精炼企业精细化管理

本文以我国铜精炼行业为例，强调实施精细化管理的意义，提出精细化管理实施所需遵循的原则及铜精炼企业在实施精细管理规程中所面临的问题，最后归纳了实施精细化管理的对策和策略，旨在为我国铜精炼企业实施有效的精细化管理提供参考意见和建议。     

企业实施ERP系统的风险分析与控制探索

企业实施ERP系统的首要任务是解决投资的风险问题，这种风险存在于实施过程的整个周期中，它包括项目规划、项目预准备、实施过程和系统运行。章围绕金川公司信息化建设提出的要求，从实施ERP系统将面临的软件风险、实施风险、转变风险作了较深刻的论述；同时，探索性地阐述了预防这些风险，企业在实施ERP项目时应采取的对策与进行的风险控制措施。     

构筑目标利润导向的全面预算管理体系的实践

文章从企业实践出发，论述了如何运用全面预算管理这一先进管理技术工具，有效组织营运，为企业战略的实施服务。本文结合企业建立和实施全面预算管理体系的实践，剖析了建立和实施全面预算管理体系的重点和难点，阐述了如何建立和实施全面预算管理体系；目标管理；绩效考核。     

中小企业与ERP

中国有几百万个有一定规模的中小企业，在企业信息化的过程中，他们大部分都将或早或晚地采用ERP系统来提升在国际市场上的竞争能力，为了能够正确引导中小企业选择与实施ERP系统，对ERP系统在中小企业的实施提供一些经验，希望能够帮助中小企业在实施ERP的过程中少走不必要的弯路，成功实施ERP。     

提高产品竞争力的必由之路--实施PDM

综合概述了企业实施PDM的必要性、重要性，以及企业如何来实施PDM，企业实施PDM所带来的效益等。     

完善和深化昆钢科研专利管理的思路

针对昆钢科研和专利管理的现状，论述了科研管理中，立题与解题，项目实施与技术总结的关系，专利管理中，增效与保护，授权与实施的关系。提出了建立企业难题库，实行立题与解题分离管理及建立科研基金，提高专利实施率等建议对策。     

采用现代化管理方法 实施高标准班组建设工程

采用现代化管理方法实施高标准班组建设工程王恩顺，周东晨唐山钢铁（集团）公司从１９８６年开始实施班组建设工程，推动了企业“双文明”建设水平的提高。去年底，唐钢在总结经验的同时，进一步查找差距，提出实施高标准班组建设工程，进一步跟上国际企业管理新潮流，坚...     

浅谈企业成功实施企业资源计划的关键因素

以某公司实施企业资源计划（ERP）过程为例，论述了企业实施ERP应该注意的几个方面，为企业成功实施ERP系统提供借鉴。     

实施ISO14000标准是外向型企业的必由之路

本文简介了实施ＩＳＯ１４０００环境管理标准的及其在国内外实施情况，指出在 中国家实施ＩＳＯ１４０００标准的机遇和挑战并存，并结合实际阐述了首钢实施ＩＳＯ１４０００标准的具体做法。     

面向大规模定制的供应链管理

本文论述了企业实施大规模生产营销的必要性，分析了中铝贵州分公司大规模定制生产模式的紧迫性，为实施大规模定制生产而必须实施的供应链管理模式。     

Drawdown due to Temporally Varying Pumping Discharge: Inversely Estimating Aquifer Parameters

A ramp kernel method is proposed for accurately calculating the drawdown due to any temporal variation in pumping discharge. The use of the ramp kernels assumes the linear variation between the two consecutive measured pumping discharges. The prior studies assume a rectangular variation between the two consecutive measured pumping discharges. In the rectangular variation, a uniform pumping rate is assumed during a time span. An analytical equation for calculating the ramp kernel is derived. An optimization method is used with the proposed ramp kernels for inversely estimating the aquifer parameters from drawdown due to an arbitrary unsteady pumping discharge. Unlike the prior methods, the proposed method accurately identifies the parameters even when the sampling interval for the drawdown and pumping discharge is longer than that needed for assuming a linear variation. The proposed method outperforms the prior method. Application of the proposed method is illustrated using examples.     

New Orleans Levee System Performance during Hurricane Katrina: London Avenue and Orleans Canal South

Hurricane Katrina was one of the worst natural disasters in U.S. history. The effects of the hurricane were particularly devastating in the city of New Orleans. Most of the damage was due to the failure of the levee system that surrounds the city to protect it from flooding. This paper presents the results of centrifuge models conducted at Rensselaer Polytechnic Institute and the U.S. Army Corps of Engineers simulating the behavior of the levees at London Avenue North and South that failed during Hurricane Katrina. Those levees failed without being overtopped by the storm surge. Also included are the results of a centrifuge model of one levee section at Orleans Canal South, which did not fail during the hurricane. The key factor of the failure mechanism of the London Avenue levees was the formation of a gap between the flooded side of the levee and the sheetpile. This gap triggered a reduction of the strength at the foundation of the protected side of the levee. The results are fully consistent with field observations.     

Evaluation, Rehabilitation Planning, and Stay-Cable Replacement Design for the Hale Boggs Bridge in Luling, Louisiana

The Hale Boggs Bridge opened to traffic on October 5, 1983. At the time, it was the first U.S. cable-stayed crossing over the Mississippi River. The PE (polyethylene) protective sheathing was damaged in many of the cables before and during installation, and after the opening of the bridge to traffic. Repairs were attempted to correct the defects in cable sheathing. Many of the repairs performed poorly and failed to protect the main tension element. The condition of 39 out of 72 cables indicated a critical need for repair and timely action was recommended. To address these damages, and to assure the structural integrity of the bridge structure, several strategies involving a range of repair and replacement options were evaluated using life cycle cost analysis. It was concluded that the strategy to replace all cables presents the best value among evaluated alternatives. The design of the complete 72 cable array replacement is the first occasion on which this process is attempted in North America. The final design of the replacement cables is heavily influenced by the geometric restrictions of the existing anchorage locations. The replacement cables are being designed for a 75-year design life and incorporated with the latest advancements in corrosion protection and vibration control. Maintenance of traffic design is an essential part of the project. The bridge is a critical regional link and constitutes a hurricane evacuation route. Traffic maintenance during cable replacement was designed to be as unobtrusive to the public and commerce as practical. This paper describes efforts associated with cable condition assessment, rehabilitation strategy, and design considerations and concepts, undertaken by the writers since 2002 to improve the condition of this major river crossing.     

Reliability-Based Optimal Design of Truss Structures Using Particle Swarm Optimization

In this work, the particle swarm optimization method is employed for the reliability-based optimal design of statically determinate truss structures. Particle swarm optimization is inspired by the social behavior of flocks (swarms) of birds and insects (particles). Every particle’s position represents a specific design. The algorithm searches the design space by adjusting the trajectories of the particles that comprise the swarm. These particles are attracted toward the positions of both their personal best solution and the best solution of the swarm in a stochastic manner. In typical structural optimization problems, safety is dealt with in a yes/no manner fulfilling the set of requirements imposed by codes of practice. Considering uncertainty for the problem parameters offers a measure to quantify safety. This measure provides a rational basis for the estimation of the reliability of the components and of the entire system. Incorporating the reliability into the structural optimization framework one can seek a reliability-based optimal design. For the problems examined herein, the reliability indexes of the structural elements are obtained from analytical expressions. The structure is subsequently analyzed as a series system of correlated elements and the Ditlevsen bounds are used for the calculation of its reliability index. The uncertain-random parameters considered in this work are the load, the yield-critical stress; and the cross sections of the elements. The considered design variables of the optimization problem are the cross-sectional areas of the groups, which control the size of the truss, and the heights and lengths that control the shape of the truss. The results of the optimization are presented for a 25-bar truss and a 30-bar arch and the robustness of the optimization scheme is discussed.     

Below-Average Bidding Method

The low-bid method, typically used for competitive bidding in the United States, may result in a contract with a firm that submits either accidentally or deliberately an unrealistically low-bid price. Such an occurrence hurts both the owner and the contractor by promoting disputes, increased costs, and schedule delays. To address this problem, other countries have adopted bidding methods based on the average of the bids submitted. One such approach is the below-average method where the winning bid is closest to but below the average of all bids. A competitive bidding model for the below-average-bid method is presented and its merits relative to the average-bid method and the low-bid method are explored. The below-average-bid process is investigated analytically and through Monte Carlo simulation. The results of bidding models for the below-average, the average, and the low-bid methods are presented in four easy-to-use nomograms which allow contractors to determine the optimal lump-sum bid price for each method without the need for complicated analysis. A comparison of the three methods provides information and insights to help owners with the difficult choice of a suitable bidding method for the project at hand.     

Case Study of Fluvial Modeling of River Responses to Dam Removal

A plan was made to remove Matilija Dam on the Ventura River. With dam removal, the delta in the reservoir and the downstream channel were expected to undergo major changes in morphology. The FLUVIAL-12 model was employed to simulate reservoir and river channel responses after dam removal. As a first step, the model was calibrated using the Ventura River data to establish its validity. In calibration, the model was used to simulate the fluvial processes starting from the time of dam completion. The simulated sediment deposition above the Matilija Dam matches closely with the deposits measured by the U.S. Bureau of Reclamation. A large amount of sediment was stored in the reservoir; some of the stored sediment would be transported downstream after dam removal. An important consequence of dam removal is the major increase of sediment release to the river channel downstream. The sediment supply to the downstream reach is not only from the stored sediment in the reservoir but also from natural sediment inflow from the upstream watershed. Therefore, sediment supply to the downstream reach will exceed the natural sediment flow before the dam presence. This situation tends to overload the downstream reach with sediment, resulting in excessive deposition. The amount of sediment release from the area above the removed dam is closely related to the changes in reservoir morphology. It is necessary to model changes in the channel bed profile and channel width during erosion in order to determine the amount of sediment removal. The amount of sediment release may not be simulated using an erodible-bed model but it may be determined using an erodible boundary model.     

Bridge Scour and Substructure Deterioration: Case Study

In 1988, the State of Mississippi set up its first statewide underwater bridge inspection program. During this inspection, serious damage was found on the substructure of two parallel bridges on I-10 near Biloxi. Significant scour had occurred, exposing the steel piling. These piles had severe corrosion with cross sections reduced by 50%. Because of the reduced cross section, the web and flanges of the piles had buckled locally. This damage was exacerbated by collisions associated with barge traffic on the waterway. This accumulation of problems resulted in a bridge on the verge of collapse. Two alternatives were used to repair the substructure. The more seriously damaged piles were encased in concrete, and the less seriously damaged ones were dewatered and a concrete seal was placed around the piles. After 10?years, the piers with pile encasements showed no additional scour effects. However, the piers with the large concrete seals had scoured by as much as 3?m (10?ft). Described in this paper is the analysis of damage, design of the repair, and a review of the performance of the two types of repair over a 10-year period.     

Evaluation of Construction Practices That Influence the Bond Strength at the Interface between Pavement Layers

This study investigated the influence of several construction practices on the bond strength at the interface between pavement layers. These practices included the surface treatment, curing time, residual application rate, and equipment tracking. Three tests were performed for estimating the bond strength between an existing hot mix asphalt (HMA) and a newly constructed HMA overlay, namely the Florida Dept. of Transportation shear tester, the University of Texas at El Paso pull off test, and the torque bond test. Testing involved a CSS-1 type emulsion as the tack coat. The results from the three tests were statistically analyzed. Generally, milling provided a significantly better bond at the interface between the existing surface and the new overlay. Curing time had a minimal effect on the bond strength. The results indicated that the absence of tack coat did not significantly affect the bond strength at the interface for the milled sections, whereas it severely decreased the strength for the nonmilled sections. The results also showed that increasing the residual rate of tack coat did not generally affect the bond strength at the interface.     

Bridge Blockage and Overbank Flow Simulations Using HEC–RAS in the Keelung River during the 2001 Nari Typhoon

On September 16, 2001, Typhoon Nari resulted in severe flooding in the Keelung River basin. More than 1,000 shipping containers were swept by the rising water from the floodplain into the river, blocking 14 bridges. A severe overbank flow due to the blockage occurred at the Ba-Tu Railway Bridge. The overbank flow then passed through a railway tunnel and inundated Keelung City, resulting in significant damage. The objective of this study was to determine the influence of the bridge blockage and the Ba-Tu overbank flow on the water stages in the Keelung River during Typhoon Nari. The floating-pier-debris module and the lateral-weir module in the Hydrologic Engineering Center–River Analysis System (HEC-RAS) unsteady-flow routing model were applied to investigate water stage variation due to the bridge blockage and overbank flow. The numerical simulation results provided by this study served as an important reference for authorities who needed to clarify the responsibility of the containers’ owners for the loss of lives and property during this typhoon.     

Influence of the chromium and ytterbium co-doping on the photoluminescence of zinc selenide crystals

The luminescent properties of ZnSe, ZnSe：Cr（0.05 at.% Cr）, ZnSe：Yb（0.03 at.% Yb） and ZnSe：Cr：Yb（0.05 at.% Cr, 0.05 at.% Yb） crystals, doped during the growth process by the chemical vapor transport method, were studied within the temperature interval of 6–300 K. At the 6 K temperature in the visible spectral range 2 bands were observed： a band in the excitonic spectral region and a band of self-activated luminescence. It was shown that co-doping of zinc selenide crystals with the chromium and ytterbium led to the combination of the impurities influence on the photoluminescent properties. At the liquid helium temperature in the middle infrared range of the spectra of the ytterbium and chromium co-doped crystal a band with the maximum localized at 1.7μm was observed, which was overlapped with a complex band in the middle-IR spectral range, characteristic for the chromium doped ZnSe crystals. On the basis of obtained data an interaction mechanism of the chromium and ytterbium co-doping impurities was proposed. Guided by the existent model of the ytterbium ion incorporation in the selenide sublattice of the ZnSe crystals, an assumption about stabilization of single charged chromium ions in the zinc sublattice crystal nodes, by means of formation of the local charge compensating clusters, was made. It was assumed that the resonant energy transfer from one chromium ion to another,which led to the concentration quenching of the IR emission in the ZnSe：Cr PL spectra, would lead to the broadening of the IR emission in the spectra of ytterbium and chromium co-doped zinc selenide crystals.g