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采用高精度的非接触式激光法设计了可对点胶机进行现场计量的检测装置;按照GB/T 26799—2011标准,采用非接触式激光法和传统法对点胶机的重复性、移动速度准确度等进行了对比试验,并用传递比较试验法验证了非接触式激光法的计量规范性。研究结果表明:非接触式激光法测得点胶机的重复性、移动速度准确度均优于传统法,传递比较试验中测得的有效行程和速率均满足工业点胶机的计量规范要求。  相似文献   
995.
Despite the huge technical and market potential for cost-effective energy efficiency investments in Southeast Asian markets, only a small fraction of this potential has been realised. Given that the major share of global future energy demand, and associated greenhouse gas emissions, will come from emerging economies, it is important to understand the barriers to mainstreaming energy efficiency into the financial sector. This paper focuses on public initiatives that support one of the main barriers: access to capital. The researchers chose Thailand as a case study because of the range of energy efficiency finance programmes that have been designed and implemented since the early 1990s. Interviews with 21 experts from government, the private sector and academia provided the core data for this research. The analysis employed a multi-level perspective and focused on the historical evolution of public support of energy efficiency finance in the country. We identified three distinct phases of public policy development over the past two decades. Despite an impressive variety of ambitious and creative programmes, the initiatives have not yet succeeded in integrating energy efficiency into the financial sector in a meaningful way. Some of the key lessons found are that (a) it is better to treat energy efficiency and renewable energy in separate financing initiatives, (b) governments find it challenging to design effective mechanisms to de-risk financial investments, and (c) international organisations play an important role in testing and facilitating the introduction of new financing approaches and mechanisms. In emerging economies, cost-effective implementation of energy efficiency measures is a promising alternative that can reduce the need for investment in large-scale power generation capacity. The researchers hope that this paper will contribute to more effective design of programmes to incentivise energy efficiency financing in Thailand and in other economies in Southeast Asia.  相似文献   
996.
以刮板输送机链自动张紧系统为研究对象,通过控制机尾电机转速和伸缩液压缸的位移,使得机尾链轮上下链张紧力始终恒定,实现刮板链动态自动张紧控制,这是一个时变的两输入两输出耦合系统。本文根据解耦和神经网络的思想,在线系统辨识和调整两个PID控制器的参数,实现了不依赖于对象模型的自适应PID解耦控制。计算机仿真结果表明,该系统具有较强的抗干扰能力和自适应能力,系统鲁棒性增强,为今后进一步研究奠定了基础。  相似文献   
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Virtual Reality - Virtual reality can be used for educational purposes, particularly in demanding professions such as firefighting. Such virtual training may be useful for preparing trainees for...  相似文献   
998.
Wang  Chaojie  Du  Jin  Fan  Xiaodan 《Machine Learning》2022,111(8):2905-2927
Machine Learning - High-dimensional covariance matrix estimation plays a central role in multivariate statistical analysis. It is well-known that the sample covariance matrix is singular when the...  相似文献   
999.
Li  Xiaoying  Peng  Suyuan  Du  Jian 《Scientometrics》2021,126(7):6225-6251

In China, Prof. Hongzhou Zhao and Zeyuan Liu are the pioneers of the concept “knowledge unit” and “knowmetrics” for measuring knowledge. However, the definition on “computable knowledge object” remains controversial so far in different fields. For example, it is defined as (1) quantitative scientific concept in natural science and engineering, (2) knowledge point in the field of education research, and (3) semantic predications, i.e., Subject-Predicate-Object (SPO) triples in biomedical fields. The Semantic MEDLINE Database (SemMedDB), a high-quality public repository of SPO triples extracted from medical literature, provides a basic data infrastructure for measuring medical knowledge. In general, the study of extracting SPO triples as computable knowledge unit from unstructured scientific text has been overwhelmingly focusing on scientific knowledge per se. Since the SPO triples would be possibly extracted from hypothetical, speculative statements or even conflicting and contradictory assertions, the knowledge status (i.e., the uncertainty), which serves as an integral and critical part of scientific knowledge has been largely overlooked. This article aims to put forward a framework for Medical Knowmetrics using the SPO triples as the knowledge unit and the uncertainty as the knowledge context. The lung cancer publications dataset is used to validate the proposed framework. The uncertainty of medical knowledge and how its status evolves over time indirectly reflect the strength of competing knowledge claims, and the probability of certainty for a given SPO triple. We try to discuss the new insights using the uncertainty-centric approaches to detect research fronts, and identify knowledge claims with high certainty level, in order to improve the efficacy of knowledge-driven decision support.

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1000.
In this paper, the problem of fault‐tolerant insensitive control is addressed for a class of linear time‐invariant continuous‐time systems against bounded time‐varying actuator faults and controller gain variations. Adaptive mechanisms are developed to adjust controller gains in order to compensate for the detrimental effects of partial loss of control effectiveness and bias‐actuator faults. Variations of controller gains arise from time‐varying and bounded perturbations that are supposed to always exist in adaptive mechanisms. Based on the disturbed outputs of adaptive mechanisms, three different adaptive control strategies are constructed to achieve bounded stability results of the closed‐loop adaptive fault‐tolerant control systems in the presence of actuator faults and controller gain variations. Furthermore, comparisons of convergence boundaries of states and limits of control inputs among adaptive strategies are developed in this paper. The efficiency of the proposed adaptive control strategies and their comparisons are demonstrated by a rocket fairing structural‐acoustic model.  相似文献   
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