Novel model reference adaptive control laws for improved transient dynamics and guaranteed saturation constraints

In classical model reference adaptive control (MRAC), the adaptive rates must be tuned to meet multiple competing objectives. Large adaptive rates guarantee rapid convergence of the trajectory tracking error to zero. However, large adaptive rates may also induce saturation of the actuators and excessive overshoots of the closed-loop system’s trajectory tracking error. Conversely, low adaptive rates may produce unsatisfactory trajectory tracking performances. To overcome these limitations, in the classical MRAC framework, the adaptive rates must be tuned through an iterative process. Alternative approaches require to modify the plant’s reference model or the reference command input. This paper presents the first MRAC laws for nonlinear dynamical systems affected by matched and parametric uncertainties that constrain both the closed-loop system’s trajectory tracking error and the control input at all times within user-defined bounds, and enforce a user-defined rate of convergence on the trajectory tracking error. By applying the proposed MRAC laws, the adaptive rates can be set arbitrarily large and both the plant’s reference model and the reference command input can be chosen arbitrarily. The user-defined rate of convergence of the closed-loop plant’s trajectory is enforced by introducing a user-defined auxiliary reference model, which converges to the trajectory tracking error obtained by applying the classical MRAC laws before its transient dynamics has decayed, and steering the trajectory tracking error to the auxiliary reference model at a rate of convergence that is higher than the rate of convergence of the plant’s reference model. The ability of the proposed MRAC laws to prescribe the performance of the closed-loop system’s trajectory tracking error and control input is guaranteed by barrier Lyapunov functions. Numerical simulations illustrate both the applicability of our theoretical results and their effectiveness compared to other techniques such as prescribed performance control, which allows to constrain both the rate of convergence and the maximum overshoot on the trajectory tracking error of uncertain systems.     

Home IV Antibiotic Therapy and Exercise Capacity in Children with CF: A Case Series

Purpose: This case series describes the effect of home intravenous (IV) antibiotic therapy on spirometry and exercise capacity in a group of children with cystic fibrosis (CF). Methods: Outcomes from 10 children with CF who were prescribed a 14-day course of home IV antibiotics for a respiratory exacerbation are reported. All children performed spirometry and a modified shuttle test (MST) before and after 14-days of home IV therapy. Results: After 14 days, FEV₁ increased by mean (± SE) 12 ± 4 % (p < 0.05) but mean MST did not improve compared to baseline. All children improved or maintained spirometry values with treatment, however, only 5 improved MST distance. Conclusion: After 14 days of home IV antibiotic therapy, a significant improvement in spirometry, but not exercise capacity, was seen in this small series of children with CF. The lack of improvement in exercise capacity for all children following home IV antibiotic therapy suggests factors other than spirometry determine exercise capacity. Identifying and investigating the factors that influence exercise capacity during home IV antibiotic therapy requires further investigation.Key Words: cystic fibrosis, home IV therapy, FEV₁, Modified Shuttle Test     

Distributed knowledge acquisition for the automatic construction of integrated expert systems

The authors discuss the problem of distributed knowledge acquisition for the construction of complete and consistent databases in integrated expert systems via the sharing of knowledge sources of different topologies (experts, problem-oriented texts, and electronic media in the form of databases). The emphasis is on the models, methods, and algorithms of distributed knowledge acquisition from databases as additional knowledge sources. The authors describe the architecture and basic facilities of distributed knowledge acquisition, which function as a part of the AT-TECHNOLOGY tool complex.     

Chinese Culture Year Celebrated in Australia

During Chinese Vice Premier Li Keqiang’s official visit to Australia in October 2009, Chinese and Australian leaderships reached a consensus of hosting cultural years in each other’s country. From June 2010 to June 2011, "Experience Australia"—the Year of Australian Culture was successfully held in China. From June 2011 to June 2012, "Experience China"—the Year of Chinese Culture (YCCiA) is celebrated in Australia, featuring nearly 100 cultural events ranging from performing arts projects to visual art exhibitions to film festivals.     

Euro-Asia Economic Forum Highlights Public Cultural Service

Public cultural ser vice has gained increasing attention worldwide in recent years. It has become ever y government’s top priority to build a well-developed public cultural service system, provide diverse cultural products and promote cultural consumption by the public. In one-day disccusions of the Cultural Session, participants shared each other’s experience in public cultural service, in particular, concepts and practices of Xi’an City. Participants reached a consensus of increasing exchanges and cooperation in the sector of public culture in the future.     

Motor sport in France: testing-ground for the world

The birth of the automobile in the late nineteenth century was greeted with a mixture of awe, scepticism and sometimes even disdain from sections of the European public. In this article, the steps taken in France to pioneer and promote this new invention are examined. Unreliable and noisy, the early automobile owes a debt of gratitude to the French aristocracy who organised and codified motor racing in an effort to test these new inventions while at the same time introduce them to a wider public. City-to-city races demonstrated the potential of the automobile before the initiative of Gordon Bennett proved to be the catalyst for the birth of international motor sport as we recognise it today. Finally this article looks at the special connection between Le Mans and the automobile. Le Mans has, through its 24-hour race, maintained a strong link with the development of everyday automobile tourism and offers the enthusiast an alternative to the machines that reach incredible speeds on modern-day closed circuits. This article examines how French roads were veritable testing grounds for the earliest cars and how the public roads of Le Mans maintain the tradition to this day.     

新时代背景下的数学类专业新理科人才培养协同系统构建研究

该文在新时代背景下,基于系统论、控制论、协同论的视角,探讨聚焦如何培养数学类专业新理科人才。结合大数据、人工智能、5G等新技术、新业态、新变革,分别从人才培养方案、课程体系、师资队伍建设、实践环节等方面,探寻新时代背景下数学与应用数学、信息与计算科学、金融数学等与数据科学和大数据技术专业人才培养协同机制,努力构建数学类新理科专业人才培养协同系统。     

Bandpass sorting of heterogeneous cells using a single surface acoustic wave transducer pair

Separation and sorting of biological entities (viruses, bacteria, and cells) is a critical step in any microfluidic lab-on-a-chip device. Acoustofluidics platforms have demonstrated their ability to use physical characteristics of cells to perform label-free separation. Bandpass-type sorting methods of medium-sized entities from a mixture have been presented using acoustic techniques; however, they require multiple transducers, lack support for various target populations, can be sensitive to flow variations, or have not been verified for continuous flow sorting of biological cells. To our knowledge, this paper presents the first acoustic bandpass method that overcomes all these limitations and presents an inherently reconfigurable technique with a single transducer pair for stable continuous flow sorting of blood cells. The sorting method is first demonstrated for polystyrene particles of sizes 6, 10, and 14.5 μm in diameter with measured purity and efficiency coefficients above 75 ± 6% and 85 ± 9%, respectively. The sorting strategy was further validated in the separation of red blood cells from white blood cells and 1 μm polystyrene particles with 78 ± 8% efficiency and 74 ± 6% purity, respectively, at a flow rate of at least 1 μl/min, enabling to process finger prick blood samples within minutes.     

长沙市民间自办公共阅读空间发展研究——以雨花区“和+共享图书馆”为例

[目的/意义] 针对"和+共享图书馆"的建设现状进行分析,反映长沙市民间自办公共阅读空间的一般性问题,为长沙市民间自办公共阅读空间可持续发展提出优化建议。[方法/过程] 通过现场观察、问卷调查、访谈法等方法对"和+共享图书馆"建设现状和特点进行剖析,认为存在专业人员短缺、空间利用率偏低、营销形式单一等问题。[结果/结论] 提出优化建议包括：构建运营管理机制;加强专业人员培养;增强公共阅读空间服务的可及性和丰富服务营销形式等,以促进长沙市民办公共阅读空间的良性发展。     

The efficacy of a computer-adaptive reading program on grade 5 students’ reading achievement scores

Education and Information Technologies - Reading in upper-elementary grades includes comprehending complex texts and learning disciplinary-specific vocabulary. This study aims to determine the...