造价工程师对工程造价的控制和管理

工程造价的有效控制和管理是工程建设管理的重要组成部分。对造价工程师在投资决策阶段、设计阶段、实施阶段公路建设项目的造价控制进行了论述。     

公路工程造价控制与管理的策略分析

在我国公路建设中,公路工程造价控制与管理问题是整个工程项目建设的核心,在公路建设项目中起着关键性的作用。只有对公路整体工程做到科学、合理的造价预算与控制,才能对其进行更好的管理。鉴于此,结合当前我国公路工程造价控制上存在的优势与不足,提出了相应的看法与应对措施,并研究了管理与控制工程造价的有关策略,以期实现资源的优化配置,从而推动整个建筑行业的快速发展。     

山区低等级公路投资控制探讨

山区低等级公路建设项目虽然公路等级与建设标准不高,但同样存在着地形条件复杂、工程量巨大的特点。针对山区低等级公路项目建设投资造价控制,首先分析了山区低等级公路项目建设的特点,进而分别在方案拟定设计以及施工管理两方面详细论述了控制山区低等级公路投资的可行策略,可以为山区低等级公路项目建设造价控制管理提供合理的参考。     

公路基本建设项目设计阶段工程造价控制

公路工程造价控制,是工程项目管理的重要内容。文章分析了在公路基本建设项目设计阶段控制工程造价的重要性,阐述了设计阶段工程造价控制的必要条件,提出了对公路基本建设项目工程造价进行有效控制的措施。     

公路工程造价文件编制中的常见问题

公路工程造价文件是公路设计、咨询、计划、管理、施工、审计等一系列活动中的一项基本工作。鉴于此,对影响工程造价文件编制结果准确性的部分因素进行论述,以期提高造价文件编制的准确性。     

浅谈设计单位在公路造价控制中的影响和作用

阐述设计单位对公路造价控制的重要作用,分析了现行体制下设计单位在控制公路造价中存在的问题,并提出设计单位如何积极合理的控制公路造价的对策和措施。     

浅谈公路勘察设计中存在的问题与对策

公路勘察设计是一项集物理、化学、材料学、土力学、生物学等为一体的综合化科学技术活动。公路勘察设计是公路建设的灵魂,而提高公路勘察设计质量是当前设计行业亟待解决的问题。文章以某省公路勘察设计为例,详细分析该省公路勘察设计质量和造价管理存在的问题,并提出切实有效的解决方案。     

公路设计阶段造价控制研究

公路工程项目造价成本高、周期长,如果造价控制不利会造成资金浪费。通过对比研究公路项目设计阶段在具体应用中现状,文章分析了我国公路设计阶段造价控制存在的问题,特别是在节能与环保方面的缺陷,阐述了设计阶段造价控制的意义,通过划分设计阶段造价控制的流程,运用价值工程、限额设计等分析理论,分析造价控制的目标,并提出在设计阶段有效改进造价控制的措施。     

基于神经网络的山区公路桥梁造价预测

山区公路桥梁造价预测的准确性关系着公路桥梁的投资决策,是项目管理中的一项重点工作。山区公路因所处的地理位置特殊,地质条件复杂,对于造价控制也提出了更高的要求。鉴于此,以山区公路桥梁特征为参数,研究山区公路桥梁造价预测时的神经网络的运用,通过对样本进行分析,找出工程造价与工程项目特征之间关系,以此实现山区公路桥梁造价的快速计算,并使得预算结果更为准确。     

公路工程变更的管理

加强公路工程变更的管理,对规范各参建单位的行为,确保公路工程建设质量和安全,加快工程进度,控制工程造价,进而提高公路建设管理水平具有重要的意义.     

公路施工企业降低生产成本提高经济效益的对策

文章分析公路施工企业生产成本高利润率低的现状及成因,针对当前的市场环境,提出公路施工企业降低生产成本,提高经济效益的六大对策,论证提高企业管理能力和核心竞争力是改变现状的根本办法。     

浅谈工程项目成本管理

文章分析了工程项目成本管理存在的问题,从管理人员、成本控制要素、人工费、材料费、机械使用费、项目管理费等方面提出健全项目成本管理体制的措施。     

Energy impact evaluation for eco-routing and charging of autonomous electric vehicle fleet: Ambient temperature consideration

This paper studies the heterogeneous energy cost and charging demand impact of autonomous electric vehicle (EV) fleet under different ambient temperature. A data-driven method is introduced to formulate a two-dimensional grid stochastic energy consumption model for electric vehicles. The energy consumption model aids in analyzing EV energy cost and describing uncertainties under variable average vehicle trip speed and ambient temperature conditions. An integrated eco-routing and optimal charging decision making framework is designed to improve the capability of autonomous EV’s trip level energy management in a shared fleet. The decision making process helps to find minimum energy cost routes with consideration of charging strategies and travel time requirements. By taking advantage of derived models and technologies, comprehensive case studies are performed on a data-driven simulated transportation network in New York City. Detailed results show us the heterogeneous energy impact and charging demand under different ambient temperature. By giving the same travel demand and charging station information, under the low and high ambient temperature within each month, there exist more than 20% difference of overall energy cost and 60% difference of charging demand. All studies will help to construct sustainable infrastructure for autonomous EV fleet trip level energy management in real world applications.     

工程项目的成本管理策略

从工程项目成本管理的必要性和紧迫性方面,阐述施工项目目标成本预测和成本的计划、控制和考核对目标成本进行管理等具体内容,并对目标成本管理实施要点提出建议。     

A path-based flow formulation for the traffic assignment problem

In order to improve cooperation between traffic management and travelers, traffic assignment is the key component to achieve the objectives of both traffic management and route choice decisions for travelers. Traffic assignment can be classified into two models based on the behavioral assumptions governing route choices: User Equilibrium (UE) and System Optimum (SO) traffic assignment. According to UE and SO traffic assignment, travelers usually compete to choose the least cost routes to minimize their own travel costs, while SO traffic assignment requires travelers to work cooperatively to minimize overall cost in the road network. Thus, the paradox of benefits between UE and SO indicates that both are not practical. Thus, a solution technique needs to be proposed to balance UE and SO models, which can compromise both sides and give more feasible traffic assignments. In this paper, Stackelberg game theory is introduced to the traffic assignment problem, which can achieve the trade-off process between traffic management and travelers. Since traditional traffic assignments have low convergence rates, the gradient projection algorithm is proposed to improve efficiency.     

六河五标建设管理阶段成本控制探讨

建设管理阶段的成本控制,是项目建设管理的重要环节。文章以六寨至河池高速公路№5合同段建设管理工作为例,强调了成本控制在项目建设管理工程中的重要性,分析了影响高速公路工程建设成本和进度的常见问题,探讨了在高速公路建设过程中成本控制的方法及措施。     

Joint impact of competition,ownership form and economic regulation on airport performance and pricing

The combined impact of ownership form, economic regulation and competition on airport performance is analyzed using data envelopment analysis to measure cost efficiency in the first stage and regression analysis to measure the impact of the environment in the second stage. The empirical results of an analysis of European and Australian airports over a 10 year timeframe reveal that under relatively non-competitive conditions, public airports operate less cost efficiently than fully private airports. Irrespective of ownership form, regulation is necessary to emulate competitive forces thus pushing airport management towards cost efficiency and reasonable pricing policies. Under potential regional or hub competition, economic regulation inhibits airports of any ownership form from operating and pricing efficiently. Although public and fully private airports operate equally efficiently in a competitive setting, private airports still set higher aeronautical charges. Furthermore, mixed ownership forms with a majority public holding are neither cost efficient nor low price, irrespective of the level of competition.     

The impact of strategic management and fleet planning on airline efficiency - A random effects Tobit model based on DEA efficiency scores

As a result of the liberalisation of airline markets; the strong growth of low cost carriers; the high volatility in fuel prices; and the recent global financial crisis, the cost pressure that airlines face is very substantial. In order to survive in these very competitive environments, information on what factors impact on costs and efficiency of airlines is crucial in guiding strategic change. To evaluate key determinants of 58 passenger airlines’ efficiency, this paper applies a two-stage Data Envelopment Analysis (DEA) approach, with partially bootstrapped random effects Tobit regressions in the second stage. Our results suggest that the effects of route optimisation, in the sense of average stage length of the fleet, are limited to airline technical efficiency. We show that airline size and key fleet mix characteristics, such as aircraft size and number of different aircraft families in the fleet, are more relevant to successful cost management of airlines since they have significant impacts on all three types of airline efficiency: technical, allocative and, ultimately, cost efficiency. Our results also show that despite the fuel saving benefits of younger aircraft, the age of an airline’s fleet has no significant impact on its technical efficiency, but does have a positive impact on its allocative and cost efficiency.     

Development of a sensor system for traffic data collection

Although many types of traffic sensors are currently in use, all have some drawbacks, and widespread deployment of such sensor systems has been difficult due to high costs. Due to these deficiencies, there is a need to design and evaluate a low cost sensor system that measures both vehicle speed and counts. Fulfilling this need is the primary objective of this research. Compared to the many existing infrared-based concepts that have been developed for traffic data collection, the proposed method uses a transmission-based type of optical sensor rather than a reflection-based type. Vehicles passing between sensors block transmission of the infrared signal, thus indicating the presence of a vehicle. Vehicle speeds are then determined using the known distance between multiple pairs of sensors. A prototype of the sensor system, which uses laser diode and photo detector pairs with the laser directly projected onto the photo detector, was first developed and tested in the laboratory. Subsequently this experimental prototype was implemented for field testing. The traffic flow data collected were compared to manually collected vehicle speed and traffic counts and a statistical analysis was done to evaluate the accuracy of the sensor system. The analysis found no significant difference between the data generated by the sensor system and the data collected manually at a 95% confidence interval. However, the testing scenarios were limited and so further analysis is necessary to determine the applicability in more congested urban areas. The proposed sensor system, with its simple technology and low cost, will be suitable for saturated deployment to form a densely distributed sensor network and can provide unique support for efficient traffic incident management. Additionally, because it may be quickly installed in the field without the need of elaborate fixtures, it may be deployed for use in temporary traffic management applications such as traffic management in road work zones or during special events.     

A scalable non-myopic dynamic dial-a-ride and pricing problem for competitive on-demand mobility systems

We propose a competitive on-demand mobility model using a multi-server queue system under infinite-horizon look-ahead. The proposed approach includes a novel dynamic optimization algorithm which employs a Markov decision process (MDP) and provides opportunities to revolutionize conventional transit services that are plagued by high cost, low ridership, and general inefficiency, particularly in disadvantaged communities and low-income areas. We use this model to study the implications it has for such services and investigate whether it has a distinct cost advantage and operational improvement. We develop a dynamic pricing scheme that utilizes a balking rule that incorporates socially efficient level and the revenue-maximizing price, and an equilibrium-joining threshold obtained by imposing a toll on the customers who join the system. Results of numerical simulations based on actual New York City taxicab data indicate that a competitive on-demand mobility system supported by the proposed model increases the social welfare by up to 37% on average compared to the single-server queuing system. The study offers a novel design scheme and supporting tools for more effective budget/resource allocation, planning, and operation management of flexible transit systems.