随机非完整链式系统的自适应状态反馈镇定

基于反步技术,对带有不确定非线性项和不确定非线性系数的随机非完整链式系统,设计了自适应状态反馈镇定器.给出了能够保证系统依概率几乎渐近稳定到平衡点的切换控制.最后用仿真验证了控制器的有效性.     

规范骑行参数化建模的应用与实践

针对骑行者骑行姿势不规范的问题,提出了一种用于规范骑行的参数化建模方法.首先,创建人体模型和自行车模型,定义底层参数、中间层参数和高层参数,实现模型参数化;其次,对骑行过程进行受力分析,建立动力学模型,保证虚拟骑行符合自然运动规律;最后,建立人体上下肢参数与自行车参数间约束关系,实现人体关节协调运动.对骑行过程进行运动仿真,实验结果表明,该方法能够为骑行者提供正确的姿势指导.     

2017年大樟溪流域永泰县生态系统服务功能价值评估

以大樟溪流域永泰县生态服务系统为研究对象，确定了生态系统内供水功能价值、供电功能价值、物质产出功能价值、休闲旅游价值、大气调节功能价值、调蓄洪水功能价值、降解污染物功能价值、生物栖息地功能价值8种服务功能价值为评估指标，综合运用市场价值法、旅行费用法、替代市场价值法、影子工程法等方法评估了大樟溪流域永泰县生态系统服务功能价值。研究结果表明：2017年永泰县生态系统服务总价值为149.87亿元，其中物质产出功能价值占比最大，达到了72.78亿元，是该系统的核心功能；评估的8项功能服务价值排序结果为，物质产出功能价值＞降解污染物功能价值＞调蓄洪水功能价值＞大气调节功能价值＞生物栖息功能价值＞休闲旅游功能价值＞供电功能价值＞供水功能价值，直观反映了大樟溪对当地的巨大贡献价值。结合当地特色与现状，提出了发展流域生态旅游、提升供电功能价值、提升供水功能价值的建议。     

模糊综合评价模型在水资源费测算中的应用研究

水是工业生产过程中不可缺少的资源,水资源费的波动对工业生产有着较大影响。目前全国31个省、市、自治区已先后开始征收水资源费,但征收标准存在较大差异且多数标准并未随经济社会发展而调整。根据影响水资源费的社会经济和自然环境多种要素,构建了水资源费模糊综合评价模型,并将该模型应用到江苏某市一般工业地表水的水资源费测算中。测算结果表明,不同地区水资源费与当地自然及社会经济情况相关。因此,地方政府在制定水资源费的标准时需要充分考虑当地的实际状况。     

Knowledge transfer in system modeling and its realization through an optimal allocation of information granularity

In this study, we introduce and discuss a concept of knowledge transfer in system modeling. In a nutshell, knowledge transfer is about forming ways on how a source of knowledge (namely, an existing model) can be used in presence of new, very limited experimental evidence. In virtue of the nature of the problem at hand (a situation encountered quite commonly, e.g. in project cost estimation), new data could be very limited and this scarcity of data makes it insufficient to construct a new model. At the same time, the new data originate from a similar (but not the same) phenomenon (process) for which the original model has been constructed so the existing model, even though it could applied, has to be treated with a certain level of reservation. Such situations can be encountered, e.g. in software engineering where in spite existing similarities, each project, process, or product exhibits its own unique characteristics. Taking this into consideration, the existing model is generalized (abstracted) by forming its granular counterpart – granular model where its parameters are regarded as information granules rather than numeric entities, viz. their non-numeric (granular) version is formed based on the values of the numeric parameters present in the original model. The results produced by the granular model are also granular and in this manner they become reflective of the differences existing between the current phenomenon and the process for which the previous model has been formed.In the study on knowledge transfer and reusability, information granularity is viewed as an important design asset and as such it is subject to optimization. We formulate an optimal information granularity allocation problem: assuming a certain level of granularity, distribute it optimally among the parameters of the model (making them granular) so that a certain data coverage criterion is maximized. While the underlying concept is general and applicable to a variety of models, in this study, we discuss its use to fuzzy neural networks with intent to clearly visualize the advantages of the approach and emphasize various ways of forming granular versions of the weights (parameters) of the connections of the network. Several granularity allocation protocols (ranging from a uniform distribution of granularity, symmetric and asymmetric schemes of allocation) are discussed and the effectiveness of each of them is quantified. The use of Particle Swarm Optimization (PSO) as the underlying optimization tool to realize optimal granularity allocation is discussed.     

Petri net modeling and scheduling for cyclic job shops with blocking

Cyclic scheduling is an effective scheduling method in the repetitive discrete manufacturing environment. We investigate the scheduling problem for general cyclic job shops with blocking where each machine has an input buffer of finite capacity. We develop Petri net models for the shops. We propose a sequential buffer control policy that restricts the jobs to enter the input buffer of the next machine in a specified sequence. We show that the scheduling model of a cyclic shop with finite buffers under such a buffer control policy can be transformed into a scheduling model of a cyclic shop with no buffer that can be modeled as a timed marked graph. In addition, we characterize the structural properties for deadlock detection. Finally, we present a mixed integer programming model to find an optimal deadlock-free schedule that minimizes the cycle time.     

Coupled multi-body dynamics and CFD for wind turbine simulation including explicit wind turbulence

A high fidelity approach for wind turbine aero-elastic simulations including explicit representation of the atmospheric wind turbulence is presented. The approach uses a dynamic overset computational fluid dynamics (CFD) code for the aerodynamics coupled with a multi-body dynamics (MBD) code for the motion responses to the aerodynamic loads. Mann's wind turbulence model was implemented into the CFD code as boundary and initial conditions. The wind turbulence model was validated by comparing the theoretical one-point spectrum for the three components of the velocity fluctuations, and by comparing the expected statistics from the CFD simulated wind turbulent field with the explicit wind turbulence inlet boundary from Mann model. Extensive simulations based on the proposed coupled approach were conducted with the conceptual NREL 5-MW offshore wind turbine in an increasing level of complexity, analyzing the turbine behavior as elasticity, wind shear and atmospheric wind turbulence are added to the simulations. Results are compared with the publicly available simulations results from OC3 participants, showing good agreement for the aerodynamic loads and blade tip deflections in time and frequency domains. Wind turbulence/turbine interaction was examined for the wake flow. It was found that explicit turbulence addition results in considerably increased wake diffusion. The coupled CFD/MBD approach can be extended to include multibody models of the shaft, bearings, gearbox and generator, resulting in a promising tool for wind turbine design under complex operational environments.     

现代化信息技术促进增值税管理的优势探究

信息技术的发展和普及为当代社会带来便利的同时也促进了各行各业的体制和制度等方面的改革,社会的整体变革也促进了现代化信息技术观念和水准的更新。本文就在当前营改增形势下如何利用现代信息技术促进增值税的管理进行简单的分析,针对增值税管理状况下需要优化和升级的目标、原则、条件、增值税管理中人文主义思想等方面,并以现代信息技术的融入为切入点分别进行了说明,从信息技术对增值税管理系统的促进作用、信息资源的智能节约等方面做出了详细的解析。     

基于证据理论的BOT项目风险评价

BOT是近年来国际上出现的一种新型项目融资管理模式,由于该类项目投资巨大,建设管理周期长,存在众多不确定因素,因此在实施过程中会存在巨大风险。证据理论在风险评价过程中,受人为因素影响较小,可以对BOT风险进行客观、科学的评价。最后通过具体算法证明该模型在评价BOT项目风险的可行性和有效性。     

浅谈GPRS技术在水文监测领域中的应用

水文监测系统是为了实现水利现代化、信息化的建设要求,综合水文、计算机和通信等多学科技术对湖泊、河流、水库等地域的水雨情信息进行实时测报的系统。水文监测的范围广,大部分监测点在野外,环境恶劣且都是无人职守,而数据采集一般又要求一定的时效性,尤其是在防台、抗洪期间,更要做到及时、稳定、准确。因此,实时动态地监测水位、雨量等数据,己成为当前防汛抗洪的首要工作。