从关联一顺应模式看法官庭审话语

以法官庭审话语为语料,探讨法官庭审话语在关联—顺应模式下是否会呈现新的交际特点。研究结果表明:法官与当事人的言语交际呈现出以下特点:对语境的关联顺应;对社会角色的关联顺应;对庭审程序的关联顺应。     

Low-order dynamic equivalent estimation of power systems using data of phasor measurement units

This paper utilizes data measured by phasor measurement units (PMUs) to extract a low-order dynamic equivalent model for power system stability studies. The estimated model is a 2-order model for synchronous machines. This model has the advantage of simplicity of classical model and considerably reduces the oversimplifying error of classical model. This method offers an alternative approach to analytical model reduction techniques based on the detailed system models. The proposed method uses the synchronized bus voltage and current phasors measured by PMUs. Using post disturbance data, electrical and mechanical parameters of the equivalent generator are estimated sequentially. Furthermore, a new approach for estimation of two-machine and single machine infinite bus (SMIB) equivalent systems are presented for analysis of electromechanical oscillations. To evaluate the performance of the proposed approach, simulations are performed on a two area 13-bus test system and real measured PMU data. Simulation results show that the estimated model can represent the dynamic behavior of the studied system with good approximation.     

Model predictive control suitable for closed-loop re-identification

The main problem of a closed-loop re-identification procedure is that, in general, the dynamic control and identification objectives are conflicting. In fact, to perform a suitable identification, a persistent excitation of the system is needed, while the control objective is to stabilize the system at a given equilibrium point. However, a generalization of the concept of stability, from punctual stability to (invariant) set stability, allows for a flexibility that can be used to avoid the conflict between these objectives. Taking into account that an invariant target set includes not only a stationary component, but also a transient one, the system could be excited without deteriorating the stability of the closed-loop. In this work, a MPC controller is proposed that ensures the stability of invariant sets at the same time that a signal suitable for closed-loop re-identification is generated. Several simulation results show the propose controller formulation properties.     

Property specification,process verification,and reporting – A case study with vehicle-commissioning processes

Testing in the automotive industry is supposed to guarantee that vehicles are shipped without any flaw. Respective processes are complex, due to the variety of components and electronic devices in modern vehicles. To achieve error-free processes, their formal analysis is required. Specifying and maintaining properties the processes must satisfy in a user-friendly way is a core requirement on any verification system. We have observed that there are few property templates that testing processes must adhere to, and we describe these templates. They depend on the context of the processes, e.g., the components of the vehicle or testing stations. We have developed a framework that instantiates the templates of properties at verification time and then verifies the process against these instances. To allow an automatic verification we develop a transformation of the commissioning process to a Petri net. Using a novel approach, we are able to report the found violations to the user in a user-friendly way. Our empirical evaluation with the industrial partner has shown that our framework does detect property violations in processes. From expert interviews we conclude that our framework is user-friendly and well suited to operate in a real production environment.     

基于SBM模型的中国省际全要素能源效率和污染排放效率研究

本文使用处理非期望产出的SBM模型，利用2001．2010年省际面板数据计算中国30省份的能源效率和污染排放效率及影响因素。研究结果表明，中国整体的能源效率和排放效率均在低位运行，有下滑趋势，且排放效率表现相对低落。随着时间推移，各省份和全国的能源效率和排放效率差距也有扩大趋势。整个研究期间，北京、上海、广东、海南等四地的能源效率和排放效率值均为1，实现了资源节约、环境友好的双赢局面，其他地区在节能减排上仍存在程度不一的改善空间。Tobit模型的回归结果表明，第二产业比重越高，越不利于提高各省能源效率和排放效率；政府影响力对各省能源效率和排放效率的影响为负值；贸易依存度、人口密度对各省能源效率和排放效率有正向显著影响。最后，本文提出了有关政策建议。     

Reference trajectory tuning of model predictive control

An approach to minimize tuning effort of nominal Model Predictive Control algorithms is proposed. The algorithm dynamically calculates output set points to accommodate user-defined output importance, which is more intuitive than selecting values for the MPC weighing matrices. Instead of tuning the weights on the outputs deviations from their set points, weights on the input values and input increments, which are the usual tuning parameters of MPC, the desired output control performance of the MPC can be specified by performance factors. The proposed method extends the existing methods that consider a reference trajectory for the output tracking to the case of zone control and input targets. The proposed method also assumes that, as in most commercial MPC packages, the controller has two layers: a static layer and an extended dynamic layer. The method is illustrated by three case studies, contemplating both SISO and MIMO systems. It is observed that: the output set point tracking performance can be changed without modifying the MPC tuning weights, the approach is capable of achieving similar performance to conventional MPC tuned by multiobjective optimization techniques from the literature, with a fraction of computer effort, and it can be integrated with Real Time Optimization algorithms to control complex systems, always respecting output constraints.     

Design and evaluation of a model predictive vehicle control algorithm for automated driving using a vehicle traffic simulator

This paper describes the design and evaluation of a model predictive control algorithm for automated driving on a motorway using a vehicle traffic simulator. For the development of a highly automated driving control algorithm, motion planning is necessary to satisfy driving condition in various road traffic situations. There are two key issues in motion planning of automated driving vehicles. One of the key issues is how to handle potentially dangerous situations that could occur in order to guarantee the safety of vehicles. The second key issue is how to guarantee the disturbance rejection of the controller under model uncertainties and external disturbances. To improve safety with respect to the future behaviors of subject vehicles, not the current states but rather the predicted behaviors of surrounding vehicles should be considered. The desired driving mode and a safe driving envelope are determined based on the probabilistic prediction of surrounding vehicles behaviors over a finite prediction horizon. To obtain the desired steering angle and longitudinal acceleration for maintaining the subject vehicle in the safe driving envelope during a finite prediction horizon, a motion planning controller is designed based on an model predictive control (MPC) approach. The developed control algorithm has been successfully implemented on a vehicle electronic control unit (ECU). The proposed control algorithm has been evaluated on a real-time vehicle traffic simulator. The throttle, brake, and steering control inputs and the controlled vehicle behavior have been compared to those of manual driving.     

中国农村居民口粮消费研究

中国粮食安全尤其是口粮安全问题引起人们广泛的关注。为研究农村居民口粮消费与经济因素的关系,探讨家庭收入和价格变化对中国农村居民口粮消费的影响,以及价格变化对口粮间的消费替代研究,本文对全国2003—2009年的省级农村消费数据进行了整理,采用非参数估计方法,确定AIDS消费模型的类型,并得到了口粮消费的自价格弹性、互价格弹性、支出弹性等。结果发现,随着收入的上涨,居民倾向消费更多的是水稻;小麦和水稻之间有较强的替代性。农村居民收入的增长,将推动口粮消费的变化,尤其促进水稻消费增长,因此文章最后提出了,优先重视发展水稻生产的建议。     

Optimal control of combined heat and power units under varying thermal loads

This paper describes a model based optimizer that allows a combined heat and power (CHP) unit to supply backup power to a Smart Grid on the one hand and minimize the cost for heat and power supply on the other hand. The model of the CHP unit is lean but nevertheless accurately represents the unit behavior, including thermal behavior of the storage as well as the aging effect of engine starts. Thanks to the small model dimension we can solve the optimal dispatch problem efficiently using dynamic programming. Two selected soft- and hard-ware in the loop tests are discussed to demonstrate the performance of the approach. A re-optimization strategy is discussed that allows reactions to wrong predictions of external influences like weather.