共查询到20条相似文献，搜索用时 20 毫秒
1.
Topic models are widely used for thematic structure discovery in text. But traditional topic models often require dedicated inference procedures for specific tasks at hand. Also, they are not designed to generate word-level semantic representations. To address the limitations, we propose a neural topic modeling approach based on the Generative Adversarial Nets (GANs), called Adversarial-neural Topic Model (ATM) in this paper. To our best knowledge, this work is the first attempt to use adversarial training for topic modeling. The proposed ATM models topics with dirichlet prior and employs a generator network to capture the semantic patterns among latent topics. Meanwhile, the generator could also produce word-level semantic representations. Besides, to illustrate the feasibility of porting ATM to tasks other than topic modeling, we apply ATM for open domain event extraction. To validate the effectiveness of the proposed ATM, two topic modeling benchmark corpora and an event dataset are employed in the experiments. Our experimental results on benchmark corpora show that ATM generates more coherence topics (considering five topic coherence measures), outperforming a number of competitive baselines. Moreover, the experiments on event dataset also validate that the proposed approach is able to extract meaningful events from news articles. 相似文献
2.
Kunyu Wang Engang Tian Shibin Shen Linnan Wei Jinlong Zhang 《Journal of The Franklin Institute》2019,356(15):8507-8520
This paper has investigated the input-output finite time stability (IO-FTS) for a class of networked control systems (NCSs) with network-induced delay. To reduce the frequents of packets transmission, a novel memory event-triggered scheme (METS) has been proposed. Different from existing event-triggered schemes, the proposed METS can make use of certain released packets to generate new event. By this way, the event generator can do more precise decision and better control performance can be expected. By using a Lyapunov functional method, sufficient condition for the IO-FTS of NCSs has been derived. Then a co-design method is proposed to obtain the memory feedback gains and parameters of the METS. Finally, a simulation example is carried out and the effectiveness of the designed METS is validated. The IO-FTS of NCSs with solved memory feedback gains is also confirmed. 相似文献
3.
In this paper, networked predictive control is investigated for a networked control system with quantizers by an event-driven strategy. An event generator is designed according to a deviation of state estimation between the current time and last trigger time. A predictive strategy is proposed to compensate effect of network-induced delays and packet dropouts. The quantizers are used to deal with signals by converting real-valued signals into effective ones in both feedback and forward channels. Based on a “zoom” strategy, sufficient conditions are given to ensure stabilization of the networked control system by solving linear matrix inequalities. A simulation example is proposed to exhibit advantages and availability of the developed techniques. 相似文献
4.
在电力系统中，变压器的地位十分重要，不仅所需数量多，而且性能要好，运行要安全可靠。变压器在运行中，由于各种原因将会导致变压器故障，变压器一旦发生故障，就会限制发电机的出力，减少和中断对部分用户的供电，延长变压器的维修时间，如果不能及时的发现事故并处理事故，将会对电网安全可靠供电造成很大的威胁，对国民经济造成重大的损失。 相似文献
5.
《Journal of The Franklin Institute》2022,359(2):697-718
This paper investigates an event-triggered control design approach for discrete-time linear parameter-varying (LPV) systems under control constraints. The proposed conditions can simultaneously design a parameter-dependent dynamic output feedback controller and an event generator, ensuring the closed-loop system’s regional asymptotic stability. Based on the Lyapunov stability theory, these conditions are given in terms of linear matrix inequalities (LMIs). Moreover, using some proposed optimization procedures, it is possible to minimize the number of sensor transmissions, maximize the estimation of the region of attraction of the origin, and incorporate optimal control criteria into the formulation. Through numerical examples, some comparisons with other approaches in the literature evidence the proposed technique’s efficacy. 相似文献
6.
J. Louis Tylee 《Journal of The Franklin Institute》1983,315(3):165-178
Bond graph methods are used to derive a nonlinear model of a U-tube steam generator like those used in pressurized water reactor (PWR) power plants. A major advantage of bond graph modeling is the ease with which different subsystem models can be interconnected; this feature is demonstrated in the steam generator modeling. Individual models of primary water cooling, generator tube heat capacity, secondary and downcomer fluid mass and energy flows, the feedwater supply system, and the main steam control valve are developed. The complete bond graph model is validated using data from a test reactor steam generator. 相似文献
7.
Engang Tian Kunyu Wang Xia Zhao Shibin Shen Jinliang Liu 《Journal of The Franklin Institute》2019,356(13):7210-7223
In this paper, the H∞ control problem is investigated for a class of networked control systems with network-induced delay. A memory event-triggered scheme (METS) is proposed to reduce the redundant packet transmission in the network channel. Different from the normal event-triggered scheme (ETS), some recent released packets are stored at the event generator and controller sides, which are utilized for the first time to generate the triggered events and design the memory-based controller. The proposed METS has the following two merits. (1) The information of certain recent released signals are first utilized, which helps to improve the triggering instants at the crest or trough of the responses. (2) A state-dependent time-varying threshold parameter is designed, which can adjust the packet transmission rate according to the information of the state. Based on the proposed METS, a memory event-triggered controller is designed, the controller feedback gains and triggering parameters can be co-designed by solving a set of linear matrix inequalities. Finally, an example is given to illustrate the effectiveness of the proposed method. 相似文献
8.
本文介绍了基于FPGA技术,利用VHDL编程并加以简单的外围电路构成的数控移相正弦信号发生器。具体应用FPGA芯片及D/A转换器,采用直接数字频率合成技术(DDS),设计实现了一个频率、相位可控的正弦信号发生器。采用此方法设计的数控移相正弦信号发生器能够产生频率、相位均可数字式预置并可调节的两路正弦波信号,频率范围为20Hz至20kHz,相位差范围为0-359°,步进为1°。 相似文献
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10.
Ta-Mu Chien 《Journal of The Franklin Institute》1974,298(3):181-199
The classical theory of matching an arbitrary load to a resistive generator to achieve a desired power gain is extended to matching an arbitrary load to a generator with arbitrary internal impedance. Given the load and generator impedances and the desired power gain, the necessary and sufficient conditions on the power gain is established such that there exists a lumped lossless 2-port which, when operated between two given impedances, realized the desired power gain. The constraints on the gain function are formulated in coefficient and integral form. Design procedures are outlined and illustrated by several nontrivial examples. A design chart is prepared to facilitate the engineer to carry out the details involved.The first part of the paper develops the matching theory. Part II gives design procedure and examples. 相似文献
11.
介绍了扩频信号产生器的设计方案和具体的硬件实现。方案基于FPGA和AD9779A芯片设计,结合FPGA和AD9779A二者的优点,采用软件工程化和模块化的设计方法。经实际工程验证表明,该系统稳定可靠,满足系统对不同扩频信号产生的设计需求。 相似文献
12.
基于短语本位语法体系，本文提出了一个混合模板方法用于实现汉语口语对话系统语言生成器。在此混合模板方法中：定义短语模板用于生成汉语短语；定义句子模板用于生成基本的肯定陈述句；此外还定义了句型变换规则用于生成肯定陈述之外的汉语句型，比如否定句和疑问句等。实验表明，混合模板汉语句子生成器具有高可移植性和相对令人满意的语句生成效果，由此可认为该混合模板方法是可行的。 相似文献
13.
通过高速质量块撞击炮口来推动火炮后坐是一种技术可行的火炮后坐模拟试验方法。为保证该模拟试验方法具有与实弹射击相似的后坐动态特性,基于ABAQUS软件建立了火炮模拟试验装置模型;通过对橡胶试样进行拉伸、压缩试验,得到橡胶材料的应力应变关系曲线,然后对其进行了材料评估;通过对小型橡胶波形发生器进行压缩试验,选取Ogden(N=1)模型作为试验装置中波形发生器对应的超弹性本构模型;对火炮试验装置的后坐动态特性进行了仿真研究,仿真结果与实弹射击的试验结果相吻合,验证了橡胶波形发生器的效果及该模拟试验方法的准确性。 相似文献
14.
根据大型空冷汽轮发电机的结构特点,重点研究了定子线圈的制造工艺,并就一些关键工序所采取的新工艺和新工具与水冷定子线圈进行了对比,,进而形成了一套完整的空冷定子线圈制造体系。 相似文献
15.
This paper is concerned with the event-based weighted residual generator design via non-parallel distribution compensation (PDC) scheme for fault diagnosis in discrete-time T–S fuzzy systems, under consideration of the imperfect premise matching membership functions. An event-triggered mechanism is firstly introduced to save communication resources, which leads to the premise variables of the system and observer to be asynchronous. Then, a fuzzy diagnostic observer with mismatched premise variables is designed to estimate the unmeasurable states of the system. Moreover, by using non-PDC method, a diagnostic observer-based weighted residual generator is established to improve the fault detection (FD) performance by using the information provided by each local system, in which the membership functions structure of the diagnostic observer and residual generator need not to be the same as the systems, and the L∞/L2 and L∞ FD scheme is used to optimize the FD performance. Finally, two simulation results are provided to show the efficiency of the proposed non-PDC method. 相似文献
16.
我国新一轮电力体制改革推动了发电商与售电商战略合作的进程。在分析发电商与售电商合作博弈情景条件的基础上,基于不完全契约构建发电商与售电商合作演化博弈模型,探讨双方博弈的局部均衡点及动态演化过程,并结合模拟仿真结果提出不完全契约条件下促进双方合作的激励策略。为新电改和国企改革形势下发电商和售电商合作提供参考。 相似文献
17.
Volkert van Steijn Piotr M. Korczyk Ladislav Derzsi Adam R. Abate David A. Weitz Piotr Garstecki 《Biomicrofluidics》2013,7(2)
We introduce a novel type of droplet generator that produces droplets of a volume set by the geometry of the droplet generator and not by the flow rates of the liquids. The generator consists of a classic T-junction with a bypass channel. This bypass directs the continuous fluid around the forming droplets, so that they can fill the space between the inlet of the dispersed phase and the exit of the bypass without breaking. Once filled, the dispersed phase blocks the exit of the bypass and is squeezed by the continuous fluid and broken off from the junction. We demonstrate the fixed-volume droplet generator for (i) the formation of monodisperse droplets from a source of varying flow rates, (ii) the formation of monodisperse droplets containing a gradation of solute concentration, and (iii) the parallel production of monodisperse droplets. 相似文献
18.
牛雅丹 《科技成果管理与研究》2009,(3):73-75
在稠油开采过程中,稠油井注汽用湿蒸汽发生器及其附属设备的安全高效、清洁环保运行对于稠油生产起到至关重要的作用。排放扩容器是湿蒸汽发生器附属的必备设备之一。排放扩容器运行产生噪音是注汽站噪声的主要部分,噪声峰值能达130db,会对神经系统产生不良影响。排放扩容器就是将湿蒸汽发生器及注汽干线内的高温高压气体也必须先导入的装置,通过对蒸汽发生器及管线放空,形成湿蒸汽发生器→排放管→限流孔板组→排放扩容器→放空的循环,本文通过对传统排放扩容器的噪声问题进行深入分析研究,提出解决方案,彻底治理湿蒸汽发生器在一启一停时对人体健康造成的伤害。 相似文献
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20.
Mehmet Ozen 《Journal of The Franklin Institute》2007,344(5):790-799
We investigate the structure of codes over Galois rings with respect to the Rosenbloom-Tsfasman (shortly RT) metric. We define a standard form generator matrix and show how we can determine the minimum distance of a code by taking advantage of its standard form. We compute the RT-weights of a linear code given with a generator matrix in standard form. We define maximum distance rank (shortly MDR) codes with respect to this metric and give the weights of the codewords of an MDR code. Finally, we give a decoding technique for codes over Galois rings with respect to the RT metric. 相似文献