建设工程项目设计阶段的投资控制

建设工程项目的设计阶段是决定项目投资的关键阶段,但目前这一阶段的投资控制存在不少问题,推行限额设计和推广标准设计是设计阶段投资控制的最有效措施.     

浅谈设计阶段如何控制工程造价

工程造价是进行一个工程基础建造所需要花费的全部费用.设计阶段同时又是工程造价控制的一个重要环节,是在工程项目做出投资决策后影响和控制工程造价的关键之处,本文通过对于设计阶段工程造价的分析,对于已经存在的问题进行了探讨,并针对已经存在的问题提出一些相应的改进措施,希望对于设计阶段工程造价的控制起到一定的帮助     

超低渗透油田开发项目设计阶段限额设计的应用

限额设计常在设计阶段的初期被应用,对整个投资起着全局性控制作用的方法.目前在超低渗透油田开发项目中同样也可应用.本文主要介绍限额设计的含义,超低渗透油田开发项目中限额设计的具体方法、目标设置以及主要工作内容,然后简单介绍长庆超低渗透油田开发项目中限额设计的应用体现.     

建设工程项目设计阶段的投资控制

设计阶段投资控制是建设工程项目整个实施过程投资控制的最关键环节,“实行设计招标、优化项目设计”是设计阶段投资控制的有效措施,而大力推广实行设计监理是设计阶段投资控制的保障.     

浅谈设计阶段如何有效控制工程造价

设计阶段控制造价充分体现了事前控制的思想,在此阶段控制造价能起到事半功倍的效果,控制工程造价的关键在于设计阶段。     

浅谈建设项目设计阶段暖通专业的成本控制

设计阶段是建设项目成本控制的关键与重点。尽管设计费在建设工程全过程中比例不大,但设计质量的好坏直接影响建设费用。因此,必须在设计阶段采取一些有效的措施对建设成本进行控制。     

市政工程在设计阶段的投资控制

本文对市政工程在设计阶段投资控制的现状进行了分析,同时论述了市政工程在设计阶段投资控制的重要性,并给出相应的投资控制的方法。     

浅析限额设计在工程造价控制中的重要性

长期以来,我国习惯把工程造价的控制放在施工阶段,但控制的效果并不显著。据西方一些国家分析表明,在保证工程使用功能的前提下,进行限额设计,可有效控制工程造价。就限额设计的概念及重要性进行了一些探讨。     

浅论设计阶段的工程造价控制

从六个方面探讨了建设项目设计阶段工程造价的控制。     

造价控制与限额设计

工程建设过程中造价控制是工程控制的目标之一,以加强工程造价的前期控制为出发点,叙述了建设项目在设计阶段的造价控制方法。     

阶段投资对风险投资机构投资绩效的影响:投资区域的调节作用

本文基于代理理论研究投资区域在阶段投资对风险投资机构投资绩效影响中的调节作用。以2000年~2008年间首次接受风险投资的991家创业企业为样本,使用logit回归模型,本文研究发现:当风险投资机构投资于本地(本省或本市)的创业企业时,总投资轮次增加对投资绩效有显著的负向影响;而当风险投资机构跨区域投资时,总投资轮次增加对投资绩效有显著的正向影响。上述结论表明,阶段投资的相对收益和相对成本会随着投资区域的不同而发生变化,风险投资机构在决定是否通过阶段投资来降低代理成本时需考虑投资区域这一情境因素。     

Structural design and active disturbance rejection control of rigid-flexible coupling motion stage for nanopositioning

Mechanical-bearing-guided motion stage is widely used in electronic manufacturing equipment for its excellent high-acceleration performance and low cost, but its positioning precision is limited by the friction of mechanical bearing. To this end, a rigid-flexible coupling motion stage (RFCMS) with compound flexure hinges (CFHs) and a single drive is designed to simultaneously achieve large stroke and nanoscale precision in this work. The friction dead zone is isolated by utilizing the bending deflection of CFHs. To suppress the resonance of CFHs and deal with nonlinear disturbances and uncertainties, a model-based active disturbance rejection control (model-based ADRC) is adopted based on the bending stiffness modeling of CFHs, which can improve the tracking accuracy for the position profile and reduce the estimating error of the extended state observer for the total disturbance. Despite the uncertain control input gain and the nonlinear coupling of the working stage and the rigid frame, the tracking and estimating errors of closed-loop system are theoretically investigated. Experimental results show that RFCMS with model-based ADRC strategy can achieve positioning accuracy within 100 nm in point-to-point motion and has strong robustness to load mass changes.     

指向镜控制系统的建模与设计

针对光电探测系统中常用的指向镜伺服系统,对其控制方法进行设计和仿真,构建了永磁同步电机的动力学模型. 确立了空间矢量脉宽调制的算法,并给出仿真模型和结果. 基于此系统进行了电流环、速度环、位置环的设计,采用位置前馈和重复控制器,最终得到一种易于实现、定位精度高的控制器. 理论分析和仿真实验证明,该控制器能够较好地改善伺服系统的动态特性,具有调节时间短、无超调和动态响应准确快速等优点,并能有效提高系统位置控制精度,所得结论对此类伺服系统具有一定的指导意义.     

高技术计划项目分段投资的激励契约设计

随着政府近年来对高技术计划项目的投资力度不断加大,作为项目承担主体的科研机构的道德风险问题越来越突出。因此,亟需设计一套科学合理的激励与约束机制,来提高科研机构的研发效率。为此,本文基于委托-代理理论,构建了高技术计划项目分段投资的激励契约设计模型,并分析在此模型下科研机构的分阶段选择努力水平,研究了分段投资和激励契约在减轻科研机构道德风险中的作用,最后对政府的高技术计划项目的投资管理提出了对策建议。     

Measuring design investment in firms: Conceptual foundations and exploratory UK survey

The importance of design to company and national performance has been widely discussed, with a number of studies investigating the value or impact of design on performance. However, none of these studies has measured design investment as an input against which performance can be compared. As yet, there is no established way in which design investment might be measured. Without such a method, we cannot develop a reliable picture, akin to that for R&D spending, on the impact of design spending on company performance.     

浅论高校工程建设项目投资控制

本文从高校工程建设项目的特殊性入手分析,对高校建设项目投资控制的办法进行了探讨,分析了高校项目管理的应对措施。     

Distributed-parameter control in function space

Optimal control of distributed-parameter systems is studied from a function space point of view. The adjoint-space technique of Balakrishnam is applied to solve a general class of linear distributed-parameter final-value problems in Hilbert space. The minimum-time control problem with multi-norm constraints for a general class of approximately controllable systems is treated, using the technique of Sarachik and Kranc, through the application of Hölder's inequality. Finally, a generalized Hölder's inequality for more than two Banach spaces is given, which is useful for solving a certain class of nonlinear control problems by the same methods. Two examples are included which illustrate the theory.     

浅谈建设项目设计阶段的投资控制——从设计单位的角度

工程设计是把建设单位的使用需求和现场施工的建设实际紧密结合在一起的桥梁,它关系到整个建设项目的合理性、适用性和经济性。建设项目设计阶段的投资控制是整个项目投资控制的先导,具有前瞻性和规划性。因此,通过提高设计阶段投资控制的效率,可以更好地对项目全生命周期投资控制做出贡献。     

Synthetic Lyapunov stabilization technique for designing actuation-constrained multi-input multi-output control systems

The main objective of this paper is to present a non-predictive method in the design of nonlinear multi-input multi-output (MIMO) control systems with the presence of constraints that are determinant in practical conditions, namely, the frequency bandwidth limitation of the actuation system and saturation boundaries in control commands. If these constraints are applied in the non-predictive control design problem, it is not possible to simultaneously satisfy Lyapunov stability and actuation constraints, analytically. Instead of model-predictive-based algorithms, which in most cases are computationally expensive, this paper proposes an algorithm based on synthetic Lyapunov stability. In this technique, by defining an intelligent filter applied to the system desired trajectories, defining intelligent proximity coefficients in decoupled inequalities resulting from Lyapunov stability, and determining the admissible boundaries of control commands, a space of regulatory parameters is generated. By appropriately adjusting these parameters based on statistical analysis conducted on the overall dynamics of the system, the Lyapunov stability is guaranteed, and the mentioned control constraints are not violated. In summary, the proposed control algorithm includes the formulation of discrete-time dynamics of sliding functions, the presentation of the procedure of defining and adjusting the control algorithm parameters with the proposed synthetic stability criterion, and the calculation of control inputs based on constraints imposed on the problem. Finally, the algorithm is applied to a cart moving in the X-Y plane, including two rigid cooperative arms that are carrying a load. The most important features of synthetic Lyapunov stability compared to the model predictive-based method are its small computational load and its acceptable performance in satisfying both the Lyapunov stability conditions and determinant control constraints in more realistic situations.     

公司控制权配置、行业竞争与研发投资强度

论文选取2007-2013年上市公司研发投资数据,运用单变量分组差异检验和多变量回归分析的方法,研究了公司控制权以及行业竞争对公司研发投资强度的影响。研究发现国家大股东、法人大股东、股权集中度、国家实际控制人、两权分离度对公司研发投资强度具有负向影响,而股权制衡度、机构持股对公司研发投资强度具有正向影响,大股东股权对公司研发投资强度有微弱的非线性影响;而公司市场优势对研发强度有负向影响,行业竞争对研发强度具有正向影响;在交互性上,行业竞争可以减轻国家大股东或实际控制人对公司研发投资强度的负向影响,行业竞争与股权制衡在公司研发投资的影响上具有一定替代性。