272 research outputs found
Optimal linear‐quadratic‐Gaussian control for discrete‐time linear systems with white and time‐correlated measurement Noises
No full textFirst published: 06 May 2021This article is concerned with the optimal linear-quadratic-Gaussian control problem for discrete-time linear systems corrupted by white and time-correlated measurement noises. First, an optimal predictor for the system under consideration is proposed. Then, an optimal controller is designed, which minimizes an expected loss by a control strategy where the control is a function of measurement sequence. The novelty of this article is that a new sequence instead of the original measurement sequence is used to obtain the optimal control scheme where the element in the new sequence is derived from measurement differencing. A verification example is given to illustrate the effectiveness of the developed new design method.Wei Liu, Peng Shi, Xiangpeng Xie, Dong Yue, Shumin Fe
Public Choice for Influencers Versus Celebrities: Analysis According to Edgar Morin
No full textThis article examines why the public pays more attention to influencers today than to celebrities. It aims to integrate the author\u27s ideas into the academic field of influencer research and mass culture. We will analyze the psychological differences that motivate the public\u27s adherence to influencers compared to celebrities, drawing on Edgar Morin\u27s theory of mass culture. We will conclude that these differences manifest primarily in three aspects
Glia in Health and Disease
No full textThis eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contac
Glia in Health and Disease
No full textThis eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contac
Clinical Characteristics and Prognosis of Hospital-Acquired Klebsiella pneumoniae Bacteremic Pneumonia versus Escherichia coli Bacteremic Pneumonia: A Retrospective Comparative Study
No full textFuxing Li,1,* Junqi Zhu,1,* Yaping Hang,1 Yanhui Chen,1 Shumin Gu,1 Suqin Peng,1 Youling Fang,1 Longhua Hu,1 Jianqiu Xiong2 1Department of Jiangxi Provincial Key Laboratory of Medicine, Clinical Laboratory of the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People’s Republic of China; 2Department of Nursing, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People’s Republic of China*These authors contributed equally to this workCorrespondence: Longhua Hu, Department of Jiangxi Provincial Key Laboratory of Medicine, Clinical Laboratory of the Second Affiliated Hospital of Nanchang University, Mingde Road No. 1, Nanchang, Jiangxi, 330006, People’s Republic of China, Email [email protected] Jianqiu Xiong, Department of Nursing, The Second Affiliated Hospital of Nanchang University, Mingde Road No. 1, Nanchang, Jiangxi, 330006, People’s Republic of China, Email [email protected]: This research aimed to investigate the variations in clinical features and prognosis of HABP caused by E. coli and K. pneumoniae. We also aimed to evaluate the risk variables related to 30-day death in the investigated groups.Methods: A single-center retrospective cohort research lasting four years was performed. A total of 117 patients with HABP were involved in this research. The primary prognosis was 30-day death.Results: Among 117 patients with HABP, 60 patients were infected with K. pneumoniae (KP-HABP), and 57 patients were infected with E. coli (E. coli-HABP). A higher proportion of males, ICU admission, undergoing tracheotomy and trachea cannulation, carbapenem-resistant strains, inappropriate empirical therapy (IET), immune compromise, diabetes mellitus, and sepsis were observed in the patients with KP-HABP (all P < 0.05). Meanwhile, the median SOFA score and Pitt score were significantly (
Gong xiang chu xing shi chang de sui ji mo xing
No full textPh.D.A typical ridesharing matching market consists of three parties: drivers (supply side, each equipped with one car), riders (demand side, submit trip requests and wait to be matched) and the online matching platform. Will the supply demand gap stabilize in steady state in a finite-supply ridesharing market? With a discrete-time deterministic model, we show that the answer depends on two factors: the circulation speed of cars and the patience of riders. When either the circulation speed is less than the consumption speed of initial supply or riders are impatient, supply-demand gap finally gets stabilized in steady state. On the other hand, two incentive schemes, surge pricing and driver subsidy, are frequently employed to motivate drivers to accept more trip requests in industry practice. The micro role of incentives on each trivial match can finally affect the overall macro ridesharing matching market.We provide a novel game-queue model to link the incentive scheme and evolution of the market. Specifically, we formulate each trivial match under a specific incentive strategy as a game between drivers who decides on whether accepting the trip request and the platform who makes the matching decision. Once matched, the car becomes occupied and is set available again only after completing the trip request. We model the evolution of matching market as an M/G/c+M queue where cars are servers and riders are customers waiting to be served. In the long run, we focus on two performance measures under a specific incentive strategy: driver utilization ratio and match ratio, with the former one evaluating the supply-side efficiency and the latter for demand side. One step further, we aim to find the optimal incentive strategy which achieves the maximal match ratio. We show analytically that the incentives affect the market evolution through both enlarging the effective demand intensity and disturbing the circulation speed of cars. By investigating the specific characteristics of the matching market and the queue model, we establish the conditions under which circulation of cars is accelerated or slowed down. It shows when the circulation of cars is accelerated by growing incentives, the optimal incentive strategy is shown analytically to be the one that has all demand transformed into effective demand. Otherwise when the circulation is slowed down with growing incentives, the optimal incentive strategy is approximately given by the one that has effective traffic intensity equal to one.傳統的共享出行市場由三方構成：司機（ 供給方，每人一車 ），乘客（ 需求方，向在線平台提交出行需求訂單并等待司機接單 ），以及在線撮合平台。在一個有限供給的共享出行市場，供需雙方之間的數量差距是否會在最終穩態時穩定下來？借助於離散時間下的確定參數模型，我們證明供需差距會否穩定取決於兩個因素：車輛的流轉速度和乘客的等待耐心。或者車輛的流轉再接單速度慢于車輛的接單速度，或者乘客對等待有容忍上限，在上述任何一種情況下，我們證明供需差距在穩態下都會最終穩定。另一方面，業界常用兩種激勵策略來鼓勵司機多接訂單：動態調價和司機補貼。激勵策略，看似只是在微觀層面上影響每一個乘客與司機的匹配，實則會影響整個宏觀方面的出行市場。 我們提出一個新穎的博弈-排隊模型來將微觀層面的激勵機制和宏觀層面的市 場演化有機結合起來。具體而言，對於每一個乘客提交的出行需求，司機決定是否接單，在線撮合平台則根據一定的規則決定這個匹配是否可以成行。基於此，我們用司機和在線平台之間的博弈模型來模擬被激勵機制影響下的每一個乘客與司機的匹配。一旦匹配最終得以成行，該司機即立即進入載人狀態並且直到送該乘客到達目的地方可再次接單。我們利用 M/G/c + M 排隊模型來模 擬整個出行市場的演化。相對應於排隊模型，在我們的模型中，司機即是服務器，乘客則是等待服務的顧客。長期來看，我們關注兩項核心指標，即司機佔有率和訂單匹配效率。前者注重供給方的使用效率，後者則關注需求方的滿意程度。更進一步，我們希望找出能夠最大化訂單匹配效率的最佳激勵策略。通過這樣的博弈-排隊模型，我們可以證明激勵機制可以通過擴大有效需求及擾動車輛流轉速度來影響市場運轉。通過詳細探究出行市場的定價結構及出行訂單的特征，我們確立了車輛流轉速度被加速及被減速的條件。當車輛流轉被激勵機制加速時，我們可以解析證明最佳激勵策略即是可以使得所有訂單都成為有效需求的激勵策略。反之當車輛流轉被激勵機制減速時，可以使有效交通密度等於1的激勵策略是最佳激勵策略的有效估計。Ma, Shumin.Thesis Ph.D. Chinese University of Hong Kong 2018.Includes bibliographical references (leaves 60-62).Abstracts also in Chinese.Title from PDF title page (viewed on 9 June, 2021).Ma, Shumin
Investigation Of Feel For 6dof Inputs: Isometric And Elastic Rate Control For Manipulation In 3d Environments
No full textthis paper has been conducted to compare a 6DOF elastic rate controller and a 6DOF isometric rate controller on a 3D object positioning task. With all other factors kept similar, the elastic controller is hypothesised to produce better performance. EXPERIMENT Experimental Apparatus The experiment was conducted using the MITS (Manipulation in Three Space) system developed by the author. MITS is a non-immersive stereoscopic virtual reality environment, based on a SGI IRIS 4D/310 GTX graphics workstation equipped with a Spaceball^TM, an Ascension Bird^TM, CrystalEyes^TM stereoscopic glasses and some self-designed controllers. MITS allows the user to perform dynamic 6 DOF manipulation tasks, such as target acquisition, critical tracking (Jex, McDonell & Phatak, 1966), and compensatory and pursuit tracking (Poulton, 1974) with a variety of 3D objects in various display and control modes. The MITS system automatically records detailed and summary data of user control behaviour and performance score and presents knowledge of results (KR) feedback whenever necessary. In this experiment, the isometric rate control mode is implemented by means of a Spaceball^TM (Model 2003). Th
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