Identification and U-control of a state-space system with time-delay

This article presents a state-space model with time-delay to map the relationship between known input-output data for discrete systems. For the given input-output data, a model identification algorithm combining parameter estimation and state estimation is proposed in line with the causality constraints. Consequently, this article proposes a least squares parameter estimation algorithm, and analyzes its convergence for the studied systems to prove that the parameter estimation errors converge to zero under the persistent excitation conditions. In control system design, the U-model based control is introduced to provide a unilateral platform to improve the design efficiency and generality. A simulation portfolio from modeling to control is provided with computational experiments to validate the derived results.     

Structural load alleviation using distributed delay shaper: Application to flexible aircraft

Lightweight flexible aircraft suffers from unwanted oscillatory vibrations during aircraft manoeuvres. A recently developed distributed-delay signal (DZV) shaper is therefore proposed to be applied as a feedforward controller to alleviate the manoeuvre loads, as an alternative to traditional structural filters used routinely in this context. Structural filters are essentially linear low-pass filters with bandwidth below the significant flexible modes, applied to control signals generated either by the pilot’s direct input or by the flight control system. It has been showed that if instead a properly tuned signal shaper is used, better performance can be achieved: first, the target modes are significantly attenuated while the responsiveness of the aircraft is less compromised and secondly, the oscillatory nature of the vibrations are reduced. The high fidelity simulation results on a full scaled dynamic model of a highly flexible blended wing–body (BWB) aircraft show that in comparison to traditional structural filters, signal shapers significantly reduce the wing root loading (forces and moments) which provides potential structural benefits.     

气压仪器检定装置的升级改造

文章针对气压检定装置在使用中存在的一些问题,会同厂家对其进行了升级改造。介绍了改造后的气压检定装置的设计原理、软件和硬件设计以及技术指标等,新装置集成了目前先进的计量设备及技术,编写相应的程序软件升级改造而成。可广泛适用于气象部门空盒气压表、自动站气压传感器以及部分数字压力计的计量检定工作,实现气压检定工作的自动化,提高检定数据的准确性和可靠性,并有效提高检定的工作效率。     

PI3K/AKT/GSK3β信号通路参与腺苷A1R介导异丙酚对缺血再灌注损伤大鼠的脑保护作用

目的：探讨PI3K/AKT/GSK-3β信号通路参与异丙酚对缺血再灌注损伤大鼠的脑保护作用及机制。方法：健康雄性SD大鼠72只，所有大鼠参照Zea Longa法建立局灶性脑缺血再灌注损伤的模型。随机分成6组（n=12），A-假手术组，B-模型组（MCAO），C-异丙酚组，D-异丙酚+腺苷A1R拮抗剂组（DPCPX），E-异丙酚组+PI3K特异性抑制剂（LY294002），F-异丙酚+GSK-3β抑制剂组（SB216763），观察大鼠术后24 h神经功能评分情况；LDF监测插栓前后脑血流变化；采用TTC染色法检测各组大鼠的脑梗死体积；用HE染色方法观察大鼠脑组织形态学改变；免疫组织化学法检测Bcl-2阳性细胞表达；采用TUNEL检测各组大脑脑皮质缺血周围神经元凋亡细胞的百分率。结果：与A组比较，B、C、D、E及F组大鼠行为学、脑梗死体积、细胞凋亡率、Bcl-2蛋白表达量均增加（P<0.05）；与C组比较，B、D、E组大鼠行为学评分，脑梗死体积及细胞凋亡率均明显增加，Bcl-2蛋白表达量均明显减少（P<0.01），F组Bcl-2蛋白表达量却增加，细胞凋亡率降低（P<0.05），行为学评分减少、梗死体积减少（P<0.05）。 结论：腺苷A1R介导的异丙酚对缺血再灌注损伤大鼠的神经保护作用可能与PI3K/AKT/GSK-3β信号转导通路有关。     

Anti-proliferative effects of a small molecule inhibitor of CDK AT7519 on chronic myeloid leukemia (CML) cells through halting the transition of cells from G2/M phase of the cell cycle

Pathogenesis of chronic myeloid leukemia (CML) has mostly been studied with regard to the oncogenic role of BCR/ABL fusion; however, recent disclosures have declared that the challenges with the treatment of CML patients would not be resolved until the role of other aberrancies is ignored. Given the involvement of cyclin-dependent kinases (CDKs) in the pathogenesis of CML, the present study aimed to investigate the effects of a multi-CDK inhibitor AT7519 on BCR/ABL-harboring CML-derived K562 cells. Our results showed that AT7519 effectively reduced the survival of K562 and induced its anti-proliferative effect through the induction of G2/M arrest due to elevated p21 and p27. The resulting data also revealed that either direct or indirect suppression of c-Myc using specific c-Myc inhibitor 10058-F4 and selective PI3K inhibitor CAL-101 resulted in a superior cytotoxicity, suggesting that the activation of PI3K pathway could attenuate antileukemic effects of the inhibitor, at least partly, through a c-Mycdependent mechanism. To the best of our knowledge, to date, no study has addressed the effect of autophagy on CML cell response to AT7519, and, herein, we proposed for the first time that the suppression of autophagy boosted AT7519 cytotoxicity against K562. Overall, we suggested that selective CDK inhibitor AT7519 exerted antileukemic effect against CML cells and propose a novel therapeutic application for the inhibitor either as a single agent or in combination with c-Myc and/or PI3K inhibitors.     

计及RSC控制的DFIG短路电流直流分量解析表达

现有文献针对计及转子变流器(RSC)控制的双馈感应风电机组(DFIG)定子短路电流解析表达,将定子磁链当作一阶直流衰减分量或忽略功率外环控制。基于DFIG电压、磁链和RSC控制方程,得到定子电流关于定子电压和定子功率的传递函数,提出定子电流的精确解析表达式。基于RSC内、外环PI参数关系,推导直流分量衰减时间常数和角频率关于PI参数的表达式。分析了RSC内外环PI参数对定子电流直流衰减分量的影响。仿真结果验证了解析表达式的准确性,为PI参数选取和保护装置测量、整定提供依据。     

Comparison of MPC based advanced hybrid controllers for STATCOM in medium scale PEM fuel cell systems

In this article is about off grid medium scale Proton Exchange Membrane (PEM) Fuel Cell (FC) Renewable Energy System (FCRES). It is aimed to investigate the elimination of reactive power on the loads fed from the FCRES by using PI-Model Predictive Control (PI-MPC), Fractional PI (PI^λ)-Model Predictive Control (PI^λ−MPC) and Two-Degree of Freedom PI (2DOFPI)-Model Predictive Controller (2DOFPI-MPC). The effectiveness of these controllers were examined and compared both when controlling reactive power and using different control techniques. The reactive power was attempted to be eliminated using Static Synchronous Compensator (STATCOM). An advanced controller structure has been introduced by controlling capacitor voltages by switching 24 IGBTs in the 5-level inverter within its structure. In this way, the efficiency of the system was increased. The system was simulated in MATLAB/Simulink environment. System consisted of FC, STATCOM, loads, filter, coupling inductance, measurement units and advanced hybrid controllers. In the study, system behavior was also examined in the case of compensation in the system consisting of FCs working off grid.     

气候环境实验室地面结冰云雾模拟控制系统设计

飞机结冰会引起飞机气动特性、动力系统性能改变,甚至造成飞行事故。地面结冰云雾模拟设施作为一种模拟飞机飞行结冰条件的重要设备,常用于飞机防除冰系统功能验证。针对气候环境实验室结冰云雾试验条件需要,在对地面结冰云雾模拟系统进行研究的基础上,对适用于气候环境实验室的结冰云雾模拟系统进行了设计。对系统关键设计技术、系统功能及组成进行了分析,并对控制系统方案进行了详细阐述。试验表明,控制系统人机界面友好,运行可靠,能够满足液态水含量、雾滴直径参数的精确调节,产生符合试验所需的结冰环境。     

Identifying and Verifying Vulnerabilities through PLC Network Protocol and Memory Structure Analysis

Cyberattacks on the Industrial Control System (ICS) have recently been increasing, made more intelligent by advancing technologies. As such, cybersecurity for such systems is attracting attention. As a core element of control devices, the Programmable Logic Controller (PLC) in an ICS carries out on-site control over the ICS. A cyberattack on the PLC will cause damages on the overall ICS, with Stuxnet and Duqu as the most representative cases. Thus, cybersecurity for PLCs is considered essential, and many researchers carry out a variety of analyses on the vulnerabilities of PLCs as part of preemptive efforts against attacks. In this study, a vulnerability analysis was conducted on the XGB PLC. Security vulnerabilities were identified by analyzing the network protocols and memory structure of PLCs and were utilized to launch replay attack, memory modulation attack, and FTP/Web service account theft for the verification of the results. Based on the results, the attacks were proven to be able to cause the PLC to malfunction and disable it, and the identified vulnerabilities were defined.     

Local weather prediction system for a heating plant using cognitive approaches

Present-day requirements emphasize the need of saving energy. It relates mainly to industrial companies, where the minimization of energy consumption is one of their most important tasks they face. In our paper, we deal with the design of the so-called weather prediction system (WPS) for the needs of a heating plant. The primary task of such a WPS is timely predicting expected heat consumption to prepare the technology characterized by long delays in advance. Heat prediction depends primarily on weather so the crucial part of WPS is the weather, especially temperature, prediction. However, a prediction system needs a variety of further data, too. Therefore, WPS must be regarded as a complex system, including data collection, its processing, own prediction and eventual decision support. This paper gives the overview about existing data processing systems and prediction methods and then it describes a concrete design of a WPS with distributed data measuring points (stations), which are processed using a structure of neural networks based on multilayer perceptrons (MLP) with a combination of fuzzy logic. Based on real experiments we show that also such simple means as MLPs are able to solve complex problems. The paper contains a basic methodology for designing similar WPS, too.