An improved algorithm for optimal state regulation of generalized systems

The system considered is a generalized system E = Ax + Bu, Y = Cx with matrix E singular. When the impulsive modes of the system are both controllable and observable, it is shown in this paper that these modes can be eliminated by almost any constant output feedback. For a strongly controllable and observable generalized system, after its impulsive modes are eliminated, the poles of the system can be assigned arbitrarily by state feedback. Even if the states are not available, the paper adopts an efficient method to design a compensator for the system.     

交织码在无线通信可靠性中的应用研究

在对无线通信可靠性要求较高的系统中，如何保证信息的无误接收是关键。本文讨论了交织码的纠错原理，给出了具体的编码设计，对可靠性的提高进行了定性和定量的分析，并在工程中得到了验证。     

英语微课视频的设计与制作

微课是一种能支持多种信息化的学习方式,是各种信息化学习的基础.本文通过回顾微课的发展,梳理其定义,明晰了微课视频的重要性,同时结合具体案例,阐述了高职英语微课视频"以学生为中心+互动性+情景化"的设计原则.     

关于张家口住宅开发市场的思考

合理的户型设计将成为未来住宅市场上的核心竞争力．通过分析当前张家口住宅产业发展现状和市场需求,提出了进行中小套型住宅的开发策略．     

张家口旧城改造与古建筑的保护

随着城市化进程的加快,旧城改造力度也随之加大．结合张家口的古建筑特征,探讨了进行古建筑保护的原则．     

数字化核电厂班组SSA测度方法与实验研究

情景意识(SA)问题在数字化核电厂中更为突出。为识别班组共享情景意识（SSA）水平及行为形成因子（PSF）对班组SSA的影响,基于情景意识全面评估技术（SAGAT）建立一种班组SSA测量和计算方法并进行模拟机实验。结果表明,个体SA（ISA）水平与SSA水平有关,ISA级别越高,SSA级别越高;ISA和班组SSA都受到PSF的影响,PSF的状态水平越高,ISA和SSA的水平越高;对于不同的实验场景,操纵员的ISA水平和班组SSA水平不同,这表明风险场景的症状越明显及知识经验水平越好,ISA和SSA水平就越高。最后,通过被试的自评价识别当前PSF的状态水平,主要不良的PSF是班组沟通和合作水平、压力水平、人-机界面等。这些评估结果为提高数字化核电厂人因可靠性和安全水平提供了理论支持。     

Lower bounds on lengths of checking sequences

Lower bounds on the lengths of checking sequences constructed for testing from Finite State Machine-based specifications are established. These bounds consider the case where a distinguishing sequence is used in forming state recognition and transition verification subsequences and identify the effects of overlapping among such subsequences. Empirical results show that the existing methods for construction of checking sequences provide checking sequences with lengths that are within acceptable distance to these lower bounds.     

一维驱动二维跟踪太阳自动跟踪系统设计

本文从对太阳方位变化规律的分析计算入手,利用天文时间来提供准确可靠的自动跟踪信号,并采用一维驱动实现二维精密跟踪的新技术。依此所设计的新型太阳能聚光器自动跟踪系统与同类产品相比,具有准确可靠、抗干扰能力强、成本低、方便实用等特点;这对于通过聚光方式推动太阳能应用具有重大的现实意义。     

Stereo effect of image converted from planar

Research on planar-to-stereo image conversion has significant theoretical and practical implications for image processing. In this paper we use a method which segments an image into sub-blocks to perform this kind of conversion; parameters such as random variables are used for conversion control. We use two quantitative criteria, cross-entropy and root-mean-square error, to evaluate the stereo effect. Furthermore, the stereo effect that the random variables create is discussed. The results of the experiment show that, (i) when all random variables have the same distribution, different values of these random variables only slightly affect the stereo effect; and (ii) when different distributions are applied to the random variables, the cross-entropies or root-mean-square errors are slightly different, which indicates different distributions have a small influence on the stereo effect. Generally, we recommend normal distribution for better stereo effect in most cases.     

Dynamic characteristic analysis of TBM tunnelling in mixed-face conditions

In this paper, by taking into account the periodically varying mesh stiffness in multiple pinions transmission and the speed–torque characteristics of variable frequency motor drives, the dynamic model for the revolving system of tunnel boring machine (TBM) has been established. Based on the soft ground/hard rock assumption of mixed-face conditions and the analysis of cutting force on each disc cutter and each drag bit, the time-varying excavation torque on the TBM cutterhead in mixed-face tunnelling is obtained. The dynamic excavation torque and cutterhead rotation speed are discussed and compared for TBM tunnelling in several typical mixed-face conditions, which are characterized by the area percentage of soft ground on the excavation face and the uniaxial compressive strength (UCS) of rock. The results show that the excavation torque may run up to a critical value and fluctuate greatly in extremely adverse excavation environments, which may lead to an unexpected TBM stoppage and even a catastrophic failure of the drive motor. To decrease the penetration per revolution in time through applying a lower advance velocity and a higher cutterhead revolution will significantly reduce the excavation torque and effectively avoid such situations.