Готові списки джерел за темами / Joint stationarity

Добірка наукової літератури з теми "Joint stationarity"

Автор: Grafiati
Опубліковано: 14 березня 2023

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Зміст

Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Joint stationarity".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Статті в журналах з теми "Joint stationarity"

1

Fearnhead, Paul. "Haplotypes: the joint distribution of alleles at linked loci." Journal of Applied Probability 40, no. 2 (June 2003): 505–12. http://dx.doi.org/10.1239/jap/1053003559.

Повний текст джерела
Анотація:
We prove a result concerning the joint distribution of alleles at linked loci on a chromosome drawn from the population at stationarity. For a neutral locus, the allele is a draw from the stationary distribution of the mutation process. Furthermore, this allele is independent of the alleles at different loci on any chromosomes in the population.
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Fearnhead, Paul. "Haplotypes: the joint distribution of alleles at linked loci." Journal of Applied Probability 40, no. 02 (June 2003): 505–12. http://dx.doi.org/10.1017/s0021900200019458.

Повний текст джерела
Анотація:
We prove a result concerning the joint distribution of alleles at linked loci on a chromosome drawn from the population at stationarity. For a neutral locus, the allele is a draw from the stationary distribution of the mutation process. Furthermore, this allele is independent of the alleles at different loci on any chromosomes in the population.
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Baldan, Damiano, Elisa Coraci, Franco Crosato, Maurizio Ferla, Andrea Bonometto, and Sara Morucci. "Importance of non-stationary analysis for assessing extreme sea levels under sea level rise." Natural Hazards and Earth System Sciences 22, no. 11 (November 14, 2022): 3663–77. http://dx.doi.org/10.5194/nhess-22-3663-2022.

Повний текст джерела
Анотація:
Abstract. Increased coastal flooding caused by extreme sea levels (ESLs) is one of the major hazards related to sea level rise. Estimates of return levels obtained under the framework provided by extreme-event theory might be biased under climatic non-stationarity. Additional uncertainty is related to the choice of the model. In this work, we fit several extreme-value models to two long-term sea level records from Venice (96 years) and Marseille (65 years): a generalized extreme-value (GEV) distribution, a generalized Pareto distribution (GPD), a point process (PP), the joint probability method (JPM), and the revised joint probability method (RJPM) under different detrending strategies. We model non-stationarity with a linear dependence of the model's parameters on the mean sea level. Our results show that non-stationary GEV and PP models fit the data better than stationary models. The non-stationary PP model is also able to reproduce the rate of extremes occurrence fairly well. Estimates of the return levels for non-stationary and detrended models are consistently more conservative than estimates from stationary, non-detrended models. Different models were selected as being more conservative or having lower uncertainties for the two datasets. Even though the best model is case-specific, we show that non-stationary extremes analyses can provide more robust estimates of return levels to be used in coastal protection planning.
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Stadje, Wolfgang. "Stationarity of a stochastic population flow model." Journal of Applied Probability 36, no. 1 (March 1999): 291–94. http://dx.doi.org/10.1239/jap/1032374251.

Повний текст джерела
Анотація:
We consider a classical population flow model in which individuals pass through n strata with certain state-dependent probabilities and at every time t = 0,1,2,…, there is a stochastic inflow of new individuals to every stratum. For a stationary inflow process we prove the convergence of the joint distribution of group sizes and derive the limiting Laplace transform.
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Stadje, Wolfgang. "Stationarity of a stochastic population flow model." Journal of Applied Probability 36, no. 01 (March 1999): 291–94. http://dx.doi.org/10.1017/s002190020001706x.

Повний текст джерела
Анотація:
We consider a classical population flow model in which individuals pass through n strata with certain state-dependent probabilities and at every time t = 0,1,2,…, there is a stochastic inflow of new individuals to every stratum. For a stationary inflow process we prove the convergence of the joint distribution of group sizes and derive the limiting Laplace transform.
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Zhang, Lei, Fucai Wang, Zenghui Gao, Shuangshuang Gao, and Chenghang Li. "Research on the Stationarity of Hexapod Robot Posture Adjustment." Sensors 20, no. 10 (May 18, 2020): 2859. http://dx.doi.org/10.3390/s20102859.

Повний текст джерела
Анотація:
This paper proposes a smooth adjustment method for the instability problem that occurs during the start and stop of a multi-footed robot during attitude change. First, kinematics analysis is used to establish the mapping relationship between the joint angles of the robot support legs and the body posture. The leg joint angle is a known quantity that can be measured accurately and in real time. Therefore, when the position of the foot end of the support leg is unchanged, a unique set of joint angles can be obtained with the change of body posture at a certain moment. Based on the designed mapping model, the smooth adjustment of the posture can be achieved by the smooth adjustment of the support legs. Second, a constraint index that satisfies the requirements of the robot’s steady adjustment of the robot is given. The S-curve acceleration/deceleration method is used to plan the body’s attitude angle transformation curve, and then the mapping control relationship is used to obtain the control trajectory requirements of the joint to achieve smooth adjustment. In addition, this paper also gives a simple choice and motion control method for the redundancy problem caused by the number of support legs of a multi-footed robot when the attitude is changed. The simulation and prototype experiments verify and analyze the proposed method. The results of comparative experiments show that the posture adjustment method proposed in this paper has continuous acceleration without breakpoints, the speed changes gently during the start and stop phases of the attitude transformation, and there is no sudden change in the entire process, which improves the consistency of the actual values of the attitude planning curve with the target values. The physical prototype experiment shows that the maximum deviation between the actual value of the attitude angular velocity and the target value changes from 62.5% to 5.5%, and the degree of fit increases by 57.0%. Therefore, this study solves the problem of the instability of the fuselage when the robot changes its attitude, and it provides an important reference for the multi-footed robot to improve the terrain adaptability.
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Li, Xinning, Qin Yang, Hu Wu, Shuai Tan, Qun He, Neng Wang, and Xianhai Yang. "Joints Trajectory Planning of Robot Based on Slime Mould Whale Optimization Algorithm." Algorithms 15, no. 10 (September 29, 2022): 363. http://dx.doi.org/10.3390/a15100363.

Повний текст джерела
Анотація:
The joints running trajectory of a robot directly affects it’s working efficiency, stationarity and working quality. To solve the problems of slow convergence speed and weak global search ability in the current commonly used joint trajectory optimization algorithms, a joint trajectory planning method based on slime mould whale optimization algorithm (SMWOA) was researched, which could obtain the joint trajectory within a short time and with low energy consumption. On the basis of analyses of the whale optimization algorithm (WOA) and slime mould algorithm (SMA) in detail, the SMWOA was proposed by combining the two methods. By adjusting dynamic parameters and introducing dynamic weights, the proposed SMWOA increased the probability of obtaining the global optimal solution. The optimized results of 15 benchmark functions verified that the optimization accuracy of the SMWOA is clearly better than that of other classical algorithms. An experiment was carried out in which this algorithm was applied to joint trajectory optimization. Taking 6-DOF UR5 manipulator as an example, the results show that the optimized running time of the joints is reduced by 37.674% compared with that before optimization. The efficiency of robot joint motion was improved. This study provides a theoretical basis for the optimization of other engineering fields.
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Requena, Ana I., Ilaria Prosdocimi, Thomas R. Kjeldsen, and Luis Mediero. "A bivariate trend analysis to investigate the effect of increasing urbanisation on flood characteristics." Hydrology Research 48, no. 3 (July 1, 2016): 802–21. http://dx.doi.org/10.2166/nh.2016.105.

Повний текст джерела
Анотація:
Flood frequency analyses are usually based on the assumption of stationarity, which might be unrealistic if changes in climate, land uses or urbanisation impact the study catchment. Moreover, most non-stationarity studies only focus on peak flows, ignoring other flood characteristics. In this study, the potential effect of increasing urbanisation on the bivariate relationship of peak flows and volumes is investigated in a case study in the northwest of England, consisting of an increasingly urbanised catchment and a nearby hydrologically and climatologically similar unchanged rural (control) catchment. The study is performed via Kendall's tau and copulas. Temporal trends are studied visually and by formal tests, considering variables individually and jointly. Bivariate joint return period curves associated with consecutive time periods are compared to understand the joint implications of such bivariate trends. Although no significant bivariate trends were detected, hydrologically relevant trends were found in the urbanised catchment.
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Liu, Jian, and Ed Susko. "On strict stationarity and ergodicity of a non-linear ARMA model." Journal of Applied Probability 29, no. 2 (June 1992): 363–73. http://dx.doi.org/10.2307/3214573.

Повний текст джерела
Анотація:
Two recent papers by Petruccelli and Woolford (1984) and Chan et al. (1985) showed that the key element governing ergodicity of a threshold AR(1) model is the joint behavior of the two linear AR(1) pieces falling in the two boundary threshold regimes. They used essentially the necessary and sufficient conditions for ergodicity of a general Markov chain of Tweedie (1974), (1975) in a rather clever manner. However, it is difficult to extend the results to the more general threshold ARMA models. Besides, irreducibility is also required to apply Tweedie's results. In this paper, instead of pursuing the ideas in Tweedie's results, we shall develop a criterion similar in spirit to the technique used by Beneš (1967) in the context of continuous-time Markov chains. Consequently, we derive a necessary and sufficient condition for existence of a strictly stationary solution of a general non-linear ARMA model to be introduced in Section 2 of this paper. This condition is then applied to the threshold ARMA(1, q) model to yield a sufficient condition for strict stationarity which is identical to the condition given by Petruccelli and Woolford (1984) for the threshold AR(1). Hence, the conjecture that the moving average component does not affect stationarity is partially verified. Furthermore, under an additional irreducibility assumption, ergodicity of a non-linear ARMA model is established. The paper then concludes with a necessary condition for stationarity of the threshold ARMA(1, q) model.
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Liu, Jian, and Ed Susko. "On strict stationarity and ergodicity of a non-linear ARMA model." Journal of Applied Probability 29, no. 02 (June 1992): 363–73. http://dx.doi.org/10.1017/s0021900200043114.

Повний текст джерела
Анотація:
Two recent papers by Petruccelli and Woolford (1984) and Chan et al. (1985) showed that the key element governing ergodicity of a threshold AR(1) model is the joint behavior of the two linear AR(1) pieces falling in the two boundary threshold regimes. They used essentially the necessary and sufficient conditions for ergodicity of a general Markov chain of Tweedie (1974), (1975) in a rather clever manner. However, it is difficult to extend the results to the more general threshold ARMA models. Besides, irreducibility is also required to apply Tweedie's results. In this paper, instead of pursuing the ideas in Tweedie's results, we shall develop a criterion similar in spirit to the technique used by Beneš (1967) in the context of continuous-time Markov chains. Consequently, we derive a necessary and sufficient condition for existence of a strictly stationary solution of a general non-linear ARMA model to be introduced in Section 2 of this paper. This condition is then applied to the threshold ARMA(1, q) model to yield a sufficient condition for strict stationarity which is identical to the condition given by Petruccelli and Woolford (1984) for the threshold AR(1). Hence, the conjecture that the moving average component does not affect stationarity is partially verified. Furthermore, under an additional irreducibility assumption, ergodicity of a non-linear ARMA model is established. The paper then concludes with a necessary condition for stationarity of the threshold ARMA(1, q) model.
Стилі APA, Harvard, Vancouver, ISO та ін.
Більше джерел

Дисертації з теми "Joint stationarity"

1

Singh, Navrag B. "Evaluation of Circumferential Ankle Pressure as an Ergonomic Intervention to Maintain Balance Perturbed by Localized Muscular Fatigue of the Ankle Joint." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/35686.

Повний текст джерела
Анотація:
Application of pressure in the form of taping and bracing has been shown to improve proprioception, and inducing localized muscle fatigue at various musculatures has been shown to adversely affect postural control. However, the potential for pressure application to mitigate the effects of localized muscle fatigue on postural control has not yet been determined. This study investigated specifically the effects of circumferential ankle pressure (CAP) and induced ankle fatigue on postural control. Fourteen young participants (seven males and seven females) performed fatiguing sub-maximal isotonic plantar flexion exercises on an isokinetic dynamometer, in the absence and presence of a pressure cuff (60 mm Hg) used to apply CAP. Proprioceptive acuity (PA) was determined using a passive-active joint position sense test, with categorical scores (low or high PA) used as a covariate. Postural sway during quiet standing was assessed using a force platform both pre- and post-fatigue as well as in the absence and presence of CAP. Application of CAP resulted in larger postural sway in individuals with low PA, and reduced postural sway in individuals with high PA. Fatigue effects on postural sway in individuals with low PA were more substantial as compared to individuals with high PA. CAP was found to be ineffective in mitigating the effects of fatigue on postural sway in individuals with lower PA. As a whole, the results suggest a potential for CAP as an ergonomic intervention in controlling fatigue-related fall incidents, though conclusive recommendations for use are not justified.
Master of Science
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Zafari, Zafar. "The exact tail asymptotics behaviour of the joint stationary distributions of the generalized join the shortest queueing model." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42327.

Повний текст джерела
Анотація:
Parallel queueing networks have advantage over single server queueing networks, because when some servers simultaneously serve the customers in the line, the efficiency increases. Therefore, in the real world parallel queueing servers such as computer networks and multiple parallel processors, have become common. Since then many scientists have been studying the analysis of parallel queueing networks to give the exact practical models for the real world queueing problems. One of the topics in parallel queueing networks is the two-dimensional random walk, which recently have been studied by many scientists. The formulation for a random walk model in the first quadrant has been already studied by Fayolle, Malyshev and Iasnogorodski [19]. In this thesis I extend the formulation of a general random walk model to the half plane, including the first and fourth quadrants, and by using kernel method and Tauberian-like Theorem I investigate the exact tail asymptotic behaviour of the joint stationary distribution of the generating functions. In addition, I apply the results of the formulation of a general random walk model in the half plane to the Generalized-JSQ model, which is a queueing system with two parallel servers that have three streams of arrivals, two of which are dedicated to each servers, and the third one joins the shorter queue. Suppose that arrivals are independent Poisson processes, and service times have identical exponential distributions. Although this queueing model has been already studied by Zhao and Grassmann [75], and M. Miyazawa, [56], in this thesis I will use a different method named kernel method to investigate the exact tail asymptotic behaviour of the generating functions. The kernel method is simpler and faster than other methods, since in this method we are not dealing with the explicit expressions in terms of generating functions, but we only discuss the dominant singularity and its location.
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Brahmi, Amine. "Contribution à la séparation de sources cyclo-stationnaires : application aux signaux de télécommunications, mécaniques et biomécaniques." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSES051/document.

Повний текст джерела
Анотація:
Dans cette thèse, nous nous sommes attaqués au problème de séparation aveugle de mélanges linéaires de sources ayant des propriétés de cyclo-stationnarité. Trois applications ont été abordées à savoir : télécommunications, vibrations mécaniques et biomécaniques. Dans un premier temps, deux nouvelles méthodes ont été proposées, la première a pour but de séparer aveuglement des sources cyclo-stationnaires partageant une ou plusieurs fréquences cycliques inconnues. Elle combine la diagonalisation conjointe à un nouveau détecteur de points utiles (retard-fréquence cyclique) permettant de composer l’ensemble de matrices de corrélation cyclique devant être diagonalisées conjointement. Quant à la deuxième méthode, elle vise à identifier la matrice de mélange de sources cyclostationnaires de fréquences cycliques inconnues et différentes. L’identification commence par une étape de détection des matrices de rang un, puis décompose en éléments propres le produit de matrices sélectionnées, enfin une méthode de regroupement hiérarchique restitue les colonnes de notre matrice recherchée. Les deux solutions ont été appliquées aux signaux de télécommunications. Dans un second temps, nous avons appliqué d’abord la première méthode proposée sur des signaux mécaniques issus d’un banc de roulements défaillants afin de tester son aptitude à séparer les sources. Ensuite, nous avons proposé une approche qui s’appuie sur l’analyse en composantes parcimonieuses pour séparer les composantes de la force de réaction au sol ayant des propriétés cyclo-stationnaires à l’ordre 1 et 2
In this thesis, we have tackled the problem of blind separation of linear mixtures of sources with cyclo-stationarity properties. Three applications were studied : telecommunications, mechanical vibrations and biomechanics. First, two new methods have been proposed, the first one aims to blindly separate cyclo-stationary sources sharing one or more unknown cyclic frequencies. It combines the joint diagonalization with a new useful point detector (time lag-cyclic frequency) to compose the set of cyclic correlation matrices to be jointly diagonalized. As for the second method, it aims to identify the mixture matrix of cyclo-stationary sources of unknown and different cyclic frequencies. The identification begins with a step of detecting the matrices of rank one, then the product of selected matrices is decomposed into eigen-elements, and finally a hierarchical regrouping method returns the columns of our sought matrix. Both solutions have been applied to telecommunications signals. In a second step, we first applied the first proposed method on mechanical signals coming from a bank of faulty bearings in order to test its ability to separate the sources. Next, we proposed an approach based on sparse component analysis to separate the components of the ground reaction force with cyclo-stationary properties at order 1 and 2
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Sun, Tianzhu. "Residual stress development in AA7050 stationary shoulder friction stir welds." Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/residual-stress-development-in-aa7050-stationary-shoulder-friction-stir-welds(9c4066c2-f3cf-4a3d-bfd0-3f6842de1251).html.

Повний текст джерела
Анотація:
Stationary shoulder friction stir welding (SSFSW) is a recently developed variant of conventional friction stir welding (FSW). Recent studies have shown that SSFSW can join high strength aluminum alloys with improved mechanical strength and reduced distortion as a result of a narrower and more uniform thermal profile. However, a lack of understanding on the residual stress development in the SSFSW process makes it difficult to assess the structural integrity and delays a widespread application of this technique to industry. This dissertation reports the first systematic investigation into the development of residual stress induced by the SSFSW process and comparison between SSFSW and FSW techniques. Welding residual stresses were experimentally assessed with both the contour method and neutron diffraction. The weld microstructure and hardness distributions were characterized and used to understand the formation of residual stresses during the welding process. The results have shown that for both FSW and SSFSW processes, the residual stresses distribute in the form of ‘M’ shaped profile while the magnitude and size of tensile residual stress zone were effectively reduced (by 25%) in the SSFSW process, even when input welding power was identical. Other improvements seen in the SSFSW process include a reduction in the heat affected zone width, an increase in the minimum hardness and a more uniform through-thickness microstructure and hardness. The dominating welding process parameter affecting the welding residual stress was travel speed as compared to rotation speed and tool downforce. With a 90 degree shaped shoulder, SSFSW has been shown to produce defect-free T-sections by dual fillet welds. For these components, an asymmetrical distribution of microstructure, hardness and residual stresses were found as a consequence of the thermal effects induced by second weld on the first weld. The material softening caused by the first weld provides the potential of utilizing a lower heat input on the subsequent pass so as to optimize the welding parameters.
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Miglietti, Warren Martin Andre. "High strength, ductile wide gap braze joints for stationary turbine component repairs." Thesis, Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-11112008-094325.

Повний текст джерела
Анотація:
Thesis (PhD.(Engineering)--University of Pretoria, 2008.
Summary in English. On title page: Submitted in partial fulfilment of the requirements for the degree Philosophiae Doctor in the Faculty of Engineering, Built Environment and Information Technology, University of Pretoria. Includes bibliographical references.
Стилі APA, Harvard, Vancouver, ISO та ін.
6

GRASSI, FRANCESCO. "Statistical and Graph-Based Signal Processing: Fundamental Results and Application to Cardiac Electrophysiology." Doctoral thesis, Politecnico di Torino, 2018. http://hdl.handle.net/11583/2710580.

Повний текст джерела
Анотація:
The goal of cardiac electrophysiology is to obtain information about the mechanism, function, and performance of the electrical activities of the heart, the identification of deviation from normal pattern and the design of treatments. Offering a better insight into cardiac arrhythmias comprehension and management, signal processing can help the physician to enhance the treatment strategies, in particular in case of atrial fibrillation (AF), a very common atrial arrhythmia which is associated to significant morbidities, such as increased risk of mortality, heart failure, and thromboembolic events. Catheter ablation of AF is a therapeutic technique which uses radiofrequency energy to destroy atrial tissue involved in the arrhythmia sustenance, typically aiming at the electrical disconnection of the of the pulmonary veins triggers. However, recurrence rate is still very high, showing that the very complex and heterogeneous nature of AF still represents a challenging problem. Leveraging the tools of non-stationary and statistical signal processing, the first part of our work has a twofold focus: firstly, we compare the performance of two different ablation technologies, based on contact force sensing or remote magnetic controlled, using signal-based criteria as surrogates for lesion assessment. Furthermore, we investigate the role of ablation parameters in lesion formation using the late-gadolinium enhanced magnetic resonance imaging. Secondly, we hypothesized that in human atria the frequency content of the bipolar signal is directly related to the local conduction velocity (CV), a key parameter characterizing the substrate abnormality and influencing atrial arrhythmias. Comparing the degree of spectral compression among signals recorded at different points of the endocardial surface in response to decreasing pacing rate, our experimental data demonstrate a significant correlation between CV and the corresponding spectral centroids. However, complex spatio-temporal propagation pattern characterizing AF spurred the need for new signals acquisition and processing methods. Multi-electrode catheters allow whole-chamber panoramic mapping of electrical activity but produce an amount of data which need to be preprocessed and analyzed to provide clinically relevant support to the physician. Graph signal processing has shown its potential on a variety of applications involving high-dimensional data on irregular domains and complex network. Nevertheless, though state-of-the-art graph-based methods have been successful for many tasks, so far they predominantly ignore the time-dimension of data. To address this shortcoming, in the second part of this dissertation, we put forth a Time-Vertex Signal Processing Framework, as a particular case of the multi-dimensional graph signal processing. Linking together the time-domain signal processing techniques with the tools of GSP, the Time-Vertex Signal Processing facilitates the analysis of graph structured data which also evolve in time. We motivate our framework leveraging the notion of partial differential equations on graphs. We introduce joint operators, such as time-vertex localization and we present a novel approach to significantly improve the accuracy of fast joint filtering. We also illustrate how to build time-vertex dictionaries, providing conditions for efficient invertibility and examples of constructions. The experimental results on a variety of datasets suggest that the proposed tools can bring significant benefits in various signal processing and learning tasks involving time-series on graphs. We close the gap between the two parts illustrating the application of graph and time-vertex signal processing to the challenging case of multi-channels intracardiac signals.
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Chen, Kuo-mei, and 陳國美. "Testing the existence of one joint point under trend stationary model." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/19614151296691025595.

Повний текст джерела
Анотація:
碩士
國立臺灣大學
經濟學系
85
Perron (1989) 提出：發生一次改變的時間趨勢模型比起有截距項的隨機 漫步模型更適合描述總體經濟變數的時間序列資料。然而，Perron 是由 目測圖形來決定不同的結構改變模型，而這些模型主要差別在於連結點是 否存在,本文於是計算出 Wald 和 LM 統計量,來檢定發生一次結構改變的 時間趨勢模型是否有連結點的存在。本文一方面以 $\sup$ 泛函來處理統 計量中的干擾變數，並推導對應的漸近分配；另一方面則透過電腦模擬， 得到 $\sup W_T$ 和 $\sup LM_T$ 的臨界值。我們的模擬結果也顯示， 這個統計量的 size 幾乎不受干擾變數區間的影響，但有稍微高估的現象 。而給定改變點位置下，改變幅度愈大者，檢定力也愈高；給定相同的改 變幅度，改變點位置愈接近樣本尾端時，檢定力則愈好。
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Zhong, Yangfan. "Joint Source-Channel Coding Reliability Function for Single and Multi-Terminal Communication Systems." Thesis, 2008. http://hdl.handle.net/1974/1207.

Повний текст джерела
Анотація:
Traditionally, source coding (data compression) and channel coding (error protection) are performed separately and sequentially, resulting in what we call a tandem (separate) coding system. In practical implementations, however, tandem coding might involve a large delay and a high coding/decoding complexity, since one needs to remove the redundancy in the source coding part and then insert certain redundancy in the channel coding part. On the other hand, joint source-channel coding (JSCC), which coordinates source and channel coding or combines them into a single step, may offer substantial improvements over the tandem coding approach. This thesis deals with the fundamental Shannon-theoretic limits for a variety of communication systems via JSCC. More specifically, we investigate the reliability function (which is the largest rate at which the coding probability of error vanishes exponentially with increasing blocklength) for JSCC for the following discrete-time communication systems: (i) discrete memoryless systems; (ii) discrete memoryless systems with perfect channel feedback; (iii) discrete memoryless systems with source side information; (iv) discrete systems with Markovian memory; (v) continuous-valued (particularly Gaussian) memoryless systems; (vi) discrete asymmetric 2-user source-channel systems. For the above systems, we establish upper and lower bounds for the JSCC reliability function and we analytically compute these bounds. The conditions for which the upper and lower bounds coincide are also provided. We show that the conditions are satisfied for a large class of source-channel systems, and hence exactly determine the reliability function. We next provide a systematic comparison between the JSCC reliability function and the tandem coding reliability function (the reliability function resulting from separate source and channel coding). We show that the JSCC reliability function is substantially larger than the tandem coding reliability function for most cases. In particular, the JSCC reliability function is close to twice as large as the tandem coding reliability function for many source-channel pairs. This exponent gain provides a theoretical underpinning and justification for JSCC design as opposed to the widely used tandem coding method, since JSCC will yield a faster exponential rate of decay for the system error probability and thus provides substantial reductions in complexity and coding/decoding delay for real-world communication systems.
Thesis (Ph.D, Mathematics & Statistics) -- Queen's University, 2008-05-13 22:31:56.425
Стилі APA, Harvard, Vancouver, ISO та ін.

Книги з теми "Joint stationarity"

1

Joint Symposium on Stationary Combustion NOx Control (6th 1991 Washington, D.C.). Proceedings, 1991 Joint Symposium on Stationary Combustion NOx Control. Research Triangle Park, NC: U.S. Environmental Protection Agency, Air and Energy Engineering, Research Laboratory, 1994.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Joint Symposium on Stationary Combustion NOx Control. Proceedings, 1987 Joint Symposium on Stationary Combustion NOx Control, New Orleans, LA, March 1987. Research Triangle Park, NC: U.S. Environmental Protection Agency, Air and Energy Engineering Research Laboratory, 1989.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Joint Symposium on Stationary Combustion NOx Control. Proceedings, 1987 Joint Symposium on Stationary Combustion NOx Control, New Orleans, LA, March 1987. Research Triangle Park, NC: U.S. Environmental Protection Agency, Air and Energy Engineering Research Laboratory, 1989.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Institute, Electric Power Research, and United States Environmental Protection Agency., eds. Stationary source combustion NOx control: Proceedings 1987 joint symposium held New Orleans, Louisiana, March 1987. 1987.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Частини книг з теми "Joint stationarity"

1

Zhang, Yu, Xiaodong Wang, Zhixiang Min, Shiqiang Wu, Xiufeng Wu, Jiangyu Dai, Fangfang Wang, and Ang Gao. "Adaptive Regulation of Cascade Reservoirs System Under Non-stationary Runoff." In Lecture Notes in Civil Engineering, 985–1000. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-6138-0_88.

Повний текст джерела
Анотація:
AbstractUnder the influence of climate change and human activities, the spatial and temporal distribution of river runoff has changed. The statistical characteristics of runoff such as mean, variance and extreme values have changed significantly. Hydrological stationarity has been broken, deepening the uncertainty of water resources and their utilization. Hydrological stationarity is a fundamental assumption of traditional water resources planning and management. The occurrence of non-stationarity will undoubtedly have an impact on the operation and overall benefits of reservoirs, and may even threaten the safety of reservoirs and water resources. There is uncertainty as to whether reservoirs can operate safely and still achieve their design benefits under the new runoff conditions. Therefore, it is important to carry out adaptive regulation of reservoirs in response to non-stationary runoff. Based on the multi-objective theory of large system, a multi-objective joint scheduling model of the terrace reservoir group is constructed for adaptive regulation simulation. A set of combination schemes based on optimal scheduling, flood resource utilization, water saving is constructed. The adaptive regulation is validated using a real-world example of the Xiluodu cascade and Three Gorges cascade reservoirs system in Yangtze River, China. The adaptive regulation processes are analyzed by simulation and the adaptive regulation effects are evaluated. The results show that the non-stationary runoff in upper Yangtze River has had an impact on the comprehensive benefits of large hydropower projects. The use of non-engineering measures to improve flood resource utilization, adjust upstream water use behavior and optimize reservoir scheduling are effective means to reduce the negative impact of non-stationary runoff on cascade reservoirs system.
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Dörpinghaus, Meik. "Joint Processing of Pilot and Data Symbols." In On the Achievable Rate of Stationary Fading Channels, 137–51. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-19780-2_7.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Zlatanov, Vassil. "Stationary Oscillation in Two-Mass Machine Aggregate with Universal-Joint Drive." In Advances in Mechanical Engineering, 105–13. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-29579-4_11.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Ochoa, Idoia, Pedro M. Crespo, Javier Del Ser, and Mikel Hernaez. "Joint Turbo Coding and Source-Controlled Modulation of Cycle-Stationary Sources in the Bandwidth-Limited Regime." In Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 618–25. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-16644-0_53.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Saylani, Hicham, Shahram Hosseini, and Yannick Deville. "Blind Separation of Convolutive Mixtures of Non-stationary and Temporally Uncorrelated Sources Based on Joint Diagonalization." In Lecture Notes in Computer Science, 191–99. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-31254-0_22.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Saylani, Hicham, Shahram Hosseini, and Yannick Deville. "Blind Separation of Convolutive Mixtures of Non-stationary Sources Using Joint Block Diagonalization in the Frequency Domain." In Latent Variable Analysis and Signal Separation, 97–105. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-15995-4_13.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Martin, J. P. "Stationary Shoulder Friction Stir Welding." In Proceedings of the 1st International Joint Symposium on Joining and Welding, 477–82. Elsevier, 2013. http://dx.doi.org/10.1533/978-1-78242-164-1.477.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Krishnan, Sridhar, and Behnaz Ghoraani. "Time-Frequency Analysis of Digital Audio Watermarking." In Digital Audio Watermarking Techniques and Technologies, 187–204. IGI Global, 2008. http://dx.doi.org/10.4018/978-1-59904-513-9.ch009.

Повний текст джерела
Анотація:
In this book chapter, we present an overview of our time-frequency (TF) based audio watermarking methods. First, a motivation on the necessity of data authentication, and an introduction in Digital Rights Management (DRM) to protect digital multimedia contents is presented. TF techniques provide flexible means to analyze non-stationary audio signals. We have explained the joint TF domain for watermark representation, and have employed pattern recognition schemes for watermark detection. In this chapter; we introduce two watermarking methods; embedding non-linear and linear TF signatures as watermarking signatures. Robustness of the proposed methods against common signal manipulations is also studied in this chapter.
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Gu, Irene Yu-Hua, and Vasile Gui. "Joint Space-Time-Range Mean ShiftBased Image and Video Segmentation." In Advances in Image and Video Segmentation, 113–39. IGI Global, 2006. http://dx.doi.org/10.4018/978-1-59140-753-9.ch006.

Повний текст джерела
Анотація:
This chapter addresses image and video segmentation by using mean shift-based filtering and segmentation. Mean shift is an effective and elegant method to directly seek the local modes (or, local maxima) of the probability density function without the requirement of actually estimating it. Mean shift is proportional to the normalized density gradient estimate, and is pointing to the local stationary point (or, local mode) of the density estimate at which it converges. A mean shift filter can be related to a domain filter, a range filter or a bilateral filter depending on the variable setting in the kernel, and also has its own strength due to its flexibility and statistical basis. In this chapter a variety of mean shift filtering approaches are described for image/video segmentation and nonlinear edge-preserving image smoothing. A joint space-time-range domain mean shift-based video segmentation approach is presented. Segmentation of moving/static objects/background is obtained through inter-frame mode-matching in consecutive frames and motion vector mode estimation. Newly appearing objects/regions in the current frame due to new foreground objects or uncovered background regions are segmented by intra-frame mode estimation. Examples of image/video segmentation are included to demonstrate the effectiveness and robustness of these methods. Pseudo codes of the algorithms are also included.
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Jones, Oliver P., Hans Fabricius Hansen, and Michael Zhang. "An Improved Method of Establishing Extreme Metocean Conditions in the Gulf of Mexico." In Ageing and Life Extension of Offshore Facilities, 194–204. ASME, 2022. http://dx.doi.org/10.1115/1.885789_ch13.

Повний текст джерела
Анотація:
Metocean criteria at a Floating Production Unit (FPU) in the central Gulf Of Mexico (GoM) are being reassessed to support the facility’s Life Extension. Two key shortcomings of previous approaches to the development of hurricane ‘full population’ criteria have been addressed here. These include the extrapolation of correlated grid-point ‘pooled’ data and ‘non-peak’ storm data - both of which can lead to bias in extreme value estimates. These improvements have been achieved through the identification of a statistically homogenous set of hindcast grid-points. Each grid point exhibits variability in the tail region of the distribution, as a result of limited sampling of both storm track and intensity. By first, fitting a non stationary model of the marginal and joint extremes to the tails of storm peaks from each grid point and, then, merging the resulting distribution parameters from each, we establish a method of incorporating the spatial variability in both track and intensity - across a data sparse, homogenous hurricane region - into design estimates, without recourse to grid-point pooling or track-shifting and all their inherent issues. The new method also provides a set of statistically consistent hurricane storm trajectories, based on the extrapolated ensemble of tail distribution parameters. This is expected to provide significant reductions to the joint load cases, compared to standard practise.
Стилі APA, Harvard, Vancouver, ISO та ін.

Тези доповідей конференцій з теми "Joint stationarity"

1

Biehl, Michael, Barbara Hammer, Frank-Michael Schleif, Petra Schneider, and Thomas Villmann. "Stationarity of Matrix Relevance LVQ." In 2015 International Joint Conference on Neural Networks (IJCNN). IEEE, 2015. http://dx.doi.org/10.1109/ijcnn.2015.7280441.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Poiani, Riccardo, Andrea Tirinzoni, and Marcello Restelli. "Meta-Reinforcement Learning by Tracking Task Non-stationarity." In Thirtieth International Joint Conference on Artificial Intelligence {IJCAI-21}. California: International Joint Conferences on Artificial Intelligence Organization, 2021. http://dx.doi.org/10.24963/ijcai.2021/399.

Повний текст джерела
Анотація:
Many real-world domains are subject to a structured non-stationarity which affects the agent's goals and the environmental dynamics. Meta-reinforcement learning (RL) has been shown successful for training agents that quickly adapt to related tasks. However, most of the existing meta-RL algorithms for non-stationary domains either make strong assumptions on the task generation process or require sampling from it at training time. In this paper, we propose a novel algorithm (TRIO) that optimizes for the future by explicitly tracking the task evolution through time. At training time, TRIO learns a variational module to quickly identify latent parameters from experience samples. This module is learned jointly with an optimal exploration policy that takes task uncertainty into account. At test time, TRIO tracks the evolution of the latent parameters online, hence reducing the uncertainty over future tasks and obtaining fast adaptation through the meta-learned policy. Unlike most existing methods, TRIO does not assume Markovian task-evolution processes, it does not require information about the non-stationarity at training time, and it captures complex changes undergoing in the environment. We evaluate our algorithm on different simulated problems and show it outperforms competitive baselines.
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Cestari, Daniel Moreira, and Joao Luis G. Rosa. "Stochastic and deterministic stationarity analysis of EEG data." In 2017 International Joint Conference on Neural Networks (IJCNN). IEEE, 2017. http://dx.doi.org/10.1109/ijcnn.2017.7965837.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Alippi, C., and M. Roveri. "A computational intelligence-based criterion to detect non-stationarity trends." In The 2006 IEEE International Joint Conference on Neural Network Proceedings. IEEE, 2006. http://dx.doi.org/10.1109/ijcnn.2006.247230.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Kugler, P. N. "Stationarity and nonstationarity in a self-organizing information system with primitive intentions." In 1990 IJCNN International Joint Conference on Neural Networks. IEEE, 1990. http://dx.doi.org/10.1109/ijcnn.1990.137912.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Li, Chang, and Maarten de Rijke. "Cascading Non-Stationary Bandits: Online Learning to Rank in the Non-Stationary Cascade Model." In Twenty-Eighth International Joint Conference on Artificial Intelligence {IJCAI-19}. California: International Joint Conferences on Artificial Intelligence Organization, 2019. http://dx.doi.org/10.24963/ijcai.2019/396.

Повний текст джерела
Анотація:
Non-stationarity appears in many online applications such as web search and advertising. In this paper, we study the online learning to rank problem in a non-stationary environment where user preferences change abruptly at an unknown moment in time. We consider the problem of identifying the K most attractive items and propose cascading non-stationary bandits, an online learning variant of the cascading model, where a user browses a ranked list from top to bottom and clicks on the first attractive item. We propose two algorithms for solving this non-stationary problem: CascadeDUCB and CascadeSWUCB. We analyze their performance and derive gap-dependent upper bounds on the n-step regret of these algorithms. We also establish a lower bound on the regret for cascading non-stationary bandits and show that both algorithms match the lower bound up to a logarithmic factor. Finally, we evaluate their performance on a real-world web search click dataset.
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Liyanage, Sidath Ravindra, Cuntai Guan, Haihong Zhang, Kai Keng Ang, Jian-Xin Xu, and Tong Heng Lee. "Dynamically Weighted Classification with Clustering to tackle non-stationarity in Brain computer Interfacing." In 2012 International Joint Conference on Neural Networks (IJCNN 2012 - Brisbane). IEEE, 2012. http://dx.doi.org/10.1109/ijcnn.2012.6252652.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Wang, Rundong, Runsheng Yu, Bo An, and Zinovi Rabinovich. "I²HRL: Interactive Influence-based Hierarchical Reinforcement Learning." In Twenty-Ninth International Joint Conference on Artificial Intelligence and Seventeenth Pacific Rim International Conference on Artificial Intelligence {IJCAI-PRICAI-20}. California: International Joint Conferences on Artificial Intelligence Organization, 2020. http://dx.doi.org/10.24963/ijcai.2020/433.

Повний текст джерела
Анотація:
Hierarchical reinforcement learning (HRL) is a promising approach to solve tasks with long time horizons and sparse rewards. It is often implemented as a high-level policy assigning subgoals to a low-level policy. However, it suffers the high-level non-stationarity problem since the low-level policy is constantly changing. The non-stationarity also leads to the data efficiency problem: policies need more data at non-stationary states to stabilize training. To address these issues, we propose a novel HRL method: Interactive Influence-based Hierarchical Reinforcement Learning (I^2HRL). First, inspired by agent modeling, we enable the interaction between the low-level and high-level policies to stabilize the high-level policy training. The high-level policy makes decisions conditioned on the received low-level policy representation as well as the state of the environment. Second, we furthermore stabilize the high-level policy via an information-theoretic regularization with minimal dependence on the changing low-level policy. Third, we propose the influence-based exploration to more frequently visit the non-stationary states where more transition data is needed. We experimentally validate the effectiveness of the proposed solution in several tasks in MuJoCo domains by demonstrating that our approach can significantly boost the learning performance and accelerate learning compared with state-of-the-art HRL methods.
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Losing, Viktor, Barbara Hammer, and Heiko Wersing. "Self-Adjusting Memory: How to Deal with Diverse Drift Types." In Twenty-Sixth International Joint Conference on Artificial Intelligence. California: International Joint Conferences on Artificial Intelligence Organization, 2017. http://dx.doi.org/10.24963/ijcai.2017/690.

Повний текст джерела
Анотація:
Data Mining in non-stationary data streams is particularly relevant in the context of the Internet of Things and Big Data. Its challenges arise from fundamentally different drift types violating assumptions of data independence or stationarity. Available methods often struggle with certain forms of drift or require unavailable a priori task knowledge. We propose the Self-Adjusting Memory (SAM) model for the k Nearest Neighbor (kNN) algorithm. SAM-kNN can deal with heterogeneous concept drift, i.e. different drift types and rates. Its basic idea are dedicated models for current and former concepts used according to the demands of the given situation. It can be robustly applied in practice without meta parameter optimization. We conduct an extensive evaluation on various benchmarks, consisting of artificial streams with known drift characteristics and real-world datasets. Highly competitive results throughout all experiments underline the robustness of SAM-kNN as well as its capability to handle heterogeneous concept drift.
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Yu, Shujian, Xiaoyang Wang, and José C. Príncipe. "Request-and-Reverify: Hierarchical Hypothesis Testing for Concept Drift Detection with Expensive Labels." In Twenty-Seventh International Joint Conference on Artificial Intelligence {IJCAI-18}. California: International Joint Conferences on Artificial Intelligence Organization, 2018. http://dx.doi.org/10.24963/ijcai.2018/421.

Повний текст джерела
Анотація:
One important assumption underlying common classification models is the stationarity of the data. However, in real-world streaming applications, the data concept indicated by the joint distribution of feature and label is not stationary but drifting over time. Concept drift detection aims to detect such drifts and adapt the model so as to mitigate any deterioration in the model's predictive performance. Unfortunately, most existing concept drift detection methods rely on a strong and over-optimistic condition that the true labels are available immediately for all already classified instances. In this paper, a novel Hierarchical Hypothesis Testing framework with Request-and-Reverify strategy is developed to detect concept drifts by requesting labels only when necessary. Two methods, namely Hierarchical Hypothesis Testing with Classification Uncertainty (HHT-CU) and Hierarchical Hypothesis Testing with Attribute-wise "Goodness-of-fit" (HHT-AG), are proposed respectively under the novel framework. In experiments with benchmark datasets, our methods demonstrate overwhelming advantages over state-of-the-art unsupervised drift detectors. More importantly, our methods even outperform DDM (the widely used supervised drift detector) when we use significantly fewer labels.
Стилі APA, Harvard, Vancouver, ISO та ін.

Звіти організацій з теми "Joint stationarity"

1

Sukittanon, Somsak, Les E. Atlas, James W. Pitton, and Jack McLaughlin. Non-Stationary Signal Classification Using Joint Frequency Analysis. Fort Belvoir, VA: Defense Technical Information Center, January 2003. http://dx.doi.org/10.21236/ada436792.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
Також вас можуть зацікавити розширені добірки на тему "Joint stationarity" для конкретних типів джерел:
Статті в журналах
Ми пропонуємо знижки на всі преміум-плани для авторів, чиї праці увійшли до тематичних добірок літератури. Зв'яжіться з нами, щоб отримати унікальний промокод!

До бібліографії