Relevant bibliographies by topics / Backward recurrence times / Journal articles
To see the other types of publications on this topic, follow the link: Backward recurrence times.

Journal articles on the topic 'Backward recurrence times'

Author: Grafiati
Published: 2 June 2025
Last updated: 19 July 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 31 journal articles for your research on the topic 'Backward recurrence times.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Allison, Paul D. "Survival Analysis of Backward Recurrence Times." Journal of the American Statistical Association 80, no. 390 (1985): 315–22. http://dx.doi.org/10.1080/01621459.1985.10478114.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Keiding, Niels, Jason P. Fine, Oluf H. Hansen, and Rémy Slama. "Accelerated failure time regression for backward recurrence times and current durations." Statistics & Probability Letters 81, no. 7 (2011): 724–29. http://dx.doi.org/10.1016/j.spl.2011.02.009.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Winter, B. B. "Joint simulation of backward and forward recurrence times in a renewal process." Journal of Applied Probability 26, no. 02 (1989): 404–7. http://dx.doi.org/10.1017/s002190020002739x.

Full text
Abstract:
It is shown that, in a renewal process with inter-arrival distributionF,an observation from the asymptotic (whent→∞) joint distribution of backward and forward recurrence times attcan be simulated by simulating an observation of the pair (UW, (1 –U)W), whereUandWare independent random variables withU~ uniform(0, 1) andWdistributed according to the length-biased version ofF.
APA, Harvard, Vancouver, ISO, and other styles
4

Winter, B. B. "Joint simulation of backward and forward recurrence times in a renewal process." Journal of Applied Probability 26, no. 2 (1989): 404–7. http://dx.doi.org/10.2307/3214046.

Full text
Abstract:
It is shown that, in a renewal process with inter-arrival distribution F, an observation from the asymptotic (when t →∞) joint distribution of backward and forward recurrence times at t can be simulated by simulating an observation of the pair (UW, (1 – U)W), where U and W are independent random variables with U ~ uniform(0, 1) and W distributed according to the length-biased version of F.
APA, Harvard, Vancouver, ISO, and other styles
5

Zelen, Marvin. "Forward and Backward Recurrence Times and Length Biased Sampling: Age Specific Models." Lifetime Data Analysis 10, no. 4 (2004): 325–34. http://dx.doi.org/10.1007/s10985-004-4770-1.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Gakis, K. G., and B. D. Sivazlian. "The correlation of the backward and forward recurrence times in a renewal process." Stochastic Analysis and Applications 12, no. 5 (1994): 543–49. http://dx.doi.org/10.1080/07362999408809372.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Hala, Abbas Laz* Mohamed Gomma Elnour. "RENEWAL PROCESS IN QUEUING PROBLEM AND REPLACEMENT OF MACHINE." INTERNATIONAL JOURNAL OF ENGINEERING SCIENCES & RESEARCH TECHNOLOGY 5, no. 12 (2016): 304–11. https://doi.org/10.5281/zenodo.199493.

Full text
Abstract:
The paper is studying the renewal process. There are many fields in which it’s used for example: the renewable energy (solar energy, wind energy), maintenance and replacement decision models, queuing system and other field in electronics. In this study our objective is to find the probability density function related to a renewal at a given time. Also to drive the renewal equation, how to find the current lifetime and residual life time. We obtain that as expected value of a renewal process which is the renewal function or mean-value function of the renewal process. Also we use the renewal equation and renewal reward processes in the applications. The solutions of these applications show a real answers due to reality conditions within a given accuracy.
APA, Harvard, Vancouver, ISO, and other styles
8

Eliyati, Ning, Sri Indra Maiyanti, Oki Dwipurwani, and Shaly Wanda Hamidah. "MODEL REGRESI COX UNTUK MENGANALISIS PENGARUH FAKTOR ASUPAN MAKANAN TERHADAP RISIKO KEKAMBUHAN ENDOMETRIOSIS." BAREKENG: Jurnal Ilmu Matematika dan Terapan 15, no. 1 (2021): 103–14. http://dx.doi.org/10.30598/barekengvol15iss1pp103-114.

Full text
Abstract:
This research purpose is to analyze the relationship between food intake factors (fruit, soy, milk, caffeine, red meat, garlic, ginger, seafood, cheese, green tea, brown rice, wheat, potatoes, bean sprouts, mustard greens, soft drinks and alcohol) on hazard of endometriosis recurrence, using the Cox proportional hazard model backward method. The results of the food intake factors that significantly reduced the risk of endometriosis recurrence are fruit 1-4 times/week (p-value 0.01), fruit 5-7 1-4 times/week (p-value 0.08), mustard greens 1-7 times/week (p-value 0.006), bean sprouts 3-7 (p-value 0.007) and seafood times/week. Factors that increase the risk of endometriosis recurrence are consumption of milk 3-4 times/week (p-value 0.004), seafood 1-2 times (p-value 0.00), soy 1-2 times/week (p-value 0.002), and 3-7 times/week (p-value 0.001). Soy consumption 1-2 and 3-7 times/week are likely to relapse 30.3 and 43.9 times compared to soy consumption <1 times/week. Consumption of milk 3-4 times/week has a risk of relapse 24 times compared to consume milk <1 times/week
APA, Harvard, Vancouver, ISO, and other styles
9

Lam, C. Y. Teresa. "Joint simulation of backward and forward recurrence times in a superposition of independent renewal processes." Journal of Applied Probability 28, no. 4 (1991): 930–33. http://dx.doi.org/10.2307/3214699.

Full text
Abstract:
It is shown that, in a superposition of finitely many independent renewal processes, an observation from the limiting (when t →∞) joint distribution of backward and forward recurrence times at t can be simulated by simulating an observation of the pair (UW, (1 – U)W), where U and Ware independent random variables with U ~ uniform(0, 1) and W distributed according to the limiting total life distribution of the superposition process.
APA, Harvard, Vancouver, ISO, and other styles
10

Lam, C. Y. Teresa. "Joint simulation of backward and forward recurrence times in a superposition of independent renewal processes." Journal of Applied Probability 28, no. 04 (1991): 930–33. http://dx.doi.org/10.1017/s002190020004287x.

Full text
Abstract:
It is shown that, in a superposition of finitely many independent renewal processes, an observation from the limiting (when t →∞) joint distribution of backward and forward recurrence times at t can be simulated by simulating an observation of the pair (UW, (1 – U)W), where U and Ware independent random variables with U ~ uniform(0, 1) and W distributed according to the limiting total life distribution of the superposition process.
APA, Harvard, Vancouver, ISO, and other styles
11

Cristóbal, José A., José T. Alcalá, and Jorge L. Ojeda. "Nonparametric estimation of a regression function from backward recurrence times in a cross-sectional sampling." Lifetime Data Analysis 13, no. 2 (2007): 273–93. http://dx.doi.org/10.1007/s10985-007-9033-5.

Full text
APA, Harvard, Vancouver, ISO, and other styles
12

Gakis, K. G., and B. D. Sivazlian. "The use of multiple integrals in the study of the backward and forward recurrence times for the ordinary renewal process." Stochastic Analysis and Applications 10, no. 4 (1992): 409–16. http://dx.doi.org/10.1080/07362999208809279.

Full text
APA, Harvard, Vancouver, ISO, and other styles
13

Losidis, Sotirios, and Konstadinos Politis. "The covariance of the backward and forward recurrence times in a renewal process: the stationary case and asymptotics for the ordinary case." Stochastic Models 35, no. 1 (2019): 51–62. http://dx.doi.org/10.1080/15326349.2019.1575752.

Full text
APA, Harvard, Vancouver, ISO, and other styles
14

Baccelli, François, and Serguei Foss. "On the saturation rule for the stability of queues." Journal of Applied Probability 32, no. 2 (1995): 494–507. http://dx.doi.org/10.2307/3215303.

Full text
Abstract:
This paper focuses on the stability of open queueing systems under stationary ergodic assumptions. It defines a set of conditions, the monotone separable framework, ensuring that the stability region is given by the following saturation rule: ‘saturate' the queues which are fed by the external arrival stream; look at the ‘intensity' μ of the departure stream in this saturated system; then stability holds whenever the intensity of the arrival process, say λ satisfies the condition λ < μ, whereas the network is unstable if λ > μ. Whenever the stability condition is satisfied, it is also shown that certain state variables associated with the network admit a finite stationary regime which is constructed pathwise using a Loynes-type backward argument. This framework involves two main pathwise properties, external monotonicity and separability, which are satisfied by several classical queueing networks. The main tool for the proof of this rule is subadditive ergodic theory. It is shown that, for various problems, the proposed method provides an alternative to the methods based on Harris recurrence and regeneration; this is particularly true in the Markov case, where we show that the distributional assumptions commonly made on service or arrival times so as to ensure Harris recurrence can in fact be relaxed.
APA, Harvard, Vancouver, ISO, and other styles
15

Baccelli, François, and Serguei Foss. "On the saturation rule for the stability of queues." Journal of Applied Probability 32, no. 02 (1995): 494–507. http://dx.doi.org/10.1017/s0021900200102931.

Full text
Abstract:
This paper focuses on the stability of open queueing systems under stationary ergodic assumptions. It defines a set of conditions, the monotone separable framework, ensuring that the stability region is given by the following saturation rule: ‘saturate' the queues which are fed by the external arrival stream; look at the ‘intensity' μ of the departure stream in this saturated system; then stability holds whenever the intensity of the arrival process, say λ satisfies the condition λ < μ, whereas the network is unstable if λ > μ. Whenever the stability condition is satisfied, it is also shown that certain state variables associated with the network admit a finite stationary regime which is constructed pathwise using a Loynes-type backward argument. This framework involves two main pathwise properties, external monotonicity and separability, which are satisfied by several classical queueing networks. The main tool for the proof of this rule is subadditive ergodic theory. It is shown that, for various problems, the proposed method provides an alternative to the methods based on Harris recurrence and regeneration; this is particularly true in the Markov case, where we show that the distributional assumptions commonly made on service or arrival times so as to ensure Harris recurrence can in fact be relaxed.
APA, Harvard, Vancouver, ISO, and other styles
16

Yamaguchi, Kazuo. "4. Accelerated Failure-Time Mover-Stayer Regression Models for the Analysis of Last-Episode Data." Sociological Methodology 33, no. 1 (2003): 81–110. http://dx.doi.org/10.1111/j.0081-1750.2003.t01-1-00128.x.

Full text
Abstract:
This article introduces new models for the analysis of last-episode data—that is, data about the timing of the last occurrence of a repeatable event. The new models are elaborations and extensions of a particular model for backward recurrence times from a renewal process introduced by Allison (1985), and they are accelerated failure-time mover-stayer regression models that permit the separation of covariate effects on event timing from those on event occurrence. Using the data of last residential move from the 1990 Census of Population and Housing, an application of the models, which are found to fit the data adequately, shows distinct patterns in the effects of home ownership, gender, race/ethnicity, education, marital experience, and age group on residential mobility. The patterns differ regarding the relative importance and direction of influence between the effects on the duration of residence in the same house or apartment and the effects on the lifetime probability of not experiencing any residential move.
APA, Harvard, Vancouver, ISO, and other styles
17

Anderson, Justin Q., P. A. Praveen Janantha, Diego A. Alcala, Mingzhong Wu, and Lincoln D. Carr. "Physical realization of complex dynamical pattern formation in magnetic active feedback rings." New Journal of Physics 24, no. 3 (2022): 033018. http://dx.doi.org/10.1088/1367-2630/ac47cb.

Full text
Abstract:
Abstract We report the clean experimental realization of cubic–quintic complex Ginzburg–Landau (CQCGL) physics in a single driven, damped system. Four numerically predicted categories of complex dynamical behavior and pattern formation are identified for bright and dark solitary waves propagating around an active magnetic thin film-based feedback ring: (1) periodic breathing; (2) complex recurrence; (3) spontaneous spatial shifting; and (4) intermittency. These nontransient, long lifetime behaviors are observed in self-generated spin wave envelopes circulating within a dispersive, nonlinear yttrium iron garnet waveguide. The waveguide is operated in a ring geometry in which the net losses are directly compensated for via linear amplification on each round trip (of the order of 100 ns). These behaviors exhibit periods ranging from tens to thousands of round trip times (of the order of μs) and are stable for 1000s of periods (of the order of ms). We present ten observations of these dynamical behaviors which span the experimentally accessible ranges of attractive cubic nonlinearity, dispersion, and external field strength that support the self-generation of backward volume spin waves in a four-wave-mixing dominant regime. Three-wave splitting is not explicitly forbidden and is treated as an additional source of nonlinear losses. All observed behaviors are robust over wide parameter regimes, making them promising for technological applications. We present ten experimental observations which span all categories of dynamical behavior previously theoretically predicted to be observable. This represents a complete experimental verification of the CQCGL equation as a model for the study of fundamental, complex nonlinear dynamics for driven, damped waves evolving in nonlinear, dispersive systems. The reported dynamical pattern formation of self-generated dark solitary waves in attractive nonlinearity without external sources or potentials, however, is entirely novel and is presented for both the periodic breather and complex recurrence behaviors.
APA, Harvard, Vancouver, ISO, and other styles
18

Thorisson, Hermann. "On regenerative and ergodic properties of the k-server queue with non-stationary Poisson arrivals." Journal of Applied Probability 22, no. 4 (1985): 893–902. http://dx.doi.org/10.2307/3213956.

Full text
Abstract:
We consider the stable k-server queue with non-stationary Poisson arrivals and i.i.d. service times and show that the non-time-homogeneous Markov process Zt = (the queue length and residual service times at time t) can be subordinated to a stable time-homogeneous regenerative process. As an application we show that if the system starts from given conditions at time s then the distribution of Zt stabilizes (but depends on t) as s tends backwards to –∞. Also moment and stochastic domination results are established for the delay and recurrence times of the regenerative process leading to results on uniform rates of convergence.
APA, Harvard, Vancouver, ISO, and other styles
19

Thorisson, Hermann. "On regenerative and ergodic properties of the k-server queue with non-stationary Poisson arrivals." Journal of Applied Probability 22, no. 04 (1985): 893–902. http://dx.doi.org/10.1017/s0021900200108125.

Full text
Abstract:
We consider the stable k-server queue with non-stationary Poisson arrivals and i.i.d. service times and show that the non-time-homogeneous Markov process Zt = (the queue length and residual service times at time t) can be subordinated to a stable time-homogeneous regenerative process. As an application we show that if the system starts from given conditions at time s then the distribution of Zt stabilizes (but depends on t) as s tends backwards to –∞. Also moment and stochastic domination results are established for the delay and recurrence times of the regenerative process leading to results on uniform rates of convergence.
APA, Harvard, Vancouver, ISO, and other styles
20

Craddock, Charles, Myriam Labopin, Gerard Socie, et al. "Contrasting Factors Determine the Kinetics of Disease Relapse after Allogeneic Stem Cell Transplantation (allo-SCT) for Acute Myeloid Leukaemia (AML): a Survey from the Acute Leukaemia Working Party of the EBMT." Blood 124, no. 21 (2014): 3945. http://dx.doi.org/10.1182/blood.v124.21.3945.3945.

Full text
Abstract:
Abstract Disease relapse remains the major cause of treatment failure in patients allografted for AML. Post transplant interventions, such as donor lymphocyte infusion or adjunctive targeted therapies, represent novel strategies with the potential to reduce the risk of disease recurrence. Such approaches are however critically dependent on timely intervention prior to disease relapse. Whilst the factors predicting the overall risk of relapse have been well characterized determinants of the kinetics of disease relapse have not been extensively studied. We therefore performed a systematic analysis of factors determining the kinetics of disease relapse in patients allografted for AML. 1052 patients who received an allo-SCT for AML in first complete remission (CR1) between 2000 and 2012 were studied. Median age was 50 (18-72) years. 544 patients were transplanted using a sibling donor and 508 from an adult matched-unrelated donor. 538 patients received a myeloablative and 514 a reduced intensity conditioning regimen. 923 patients had good/intermediate risk and 129 had adverse risk cytogenetics at diagnosis. A series of landmark analyses were performed at 3, 6 and 12 months in order to identify prognostic factors of relapse for patients alive and well at the beginning of each time interval. The probabilities of relapse were calculated by using the cumulative incidence estimator to accommodate for death as a competing risk. Factors predicting relapse were studied using Cox regression model including time dependent variables. A backward stepwise procedure was used for variable selection. With a median follow-up of 26 months, 244 patients relapsed. The 3 year cumulative incidence of relapse was 26% [95%CI: 23-28]. The cumulative incidence of relapse in the first three months post-transplant was 7.1% (95% CI: 5.6-8.8%), 8.3% (95% CI: 6.6-10.3) between 3-6 months, 8.3 (95% CI: 6.5-10.5) between 6 and 12 months and 3.8% (95% CI: 2.4-5.6) beyond 12 months post-transplant. Overall 84% of patients destined to relapse did so within the first year post-transplant. Factors predicting relapse for the whole population were: more than one course of chemotherapy to achieve CR1, FLT3 ITD positivity, adverse risk cytogenetics and a shorter interval from CR1 to transplant. The occurrence of acute GVHD grade II or greater (p=0.05) and chronic GVHD (p=0.03) were both associated with a lower risk of relapse. Of interest, using landmark analyses, the factors determining relapse at different stages post transplant were observed to differ. In the first 3 months post-transplant the significant factors determining relapse risk were, flt3 ITD positivity (p=0.002), adverse risk cytogenetics (p=0.02) patient age (p=0.03), and prolonged interval from diagnosis to CR1 (p=0.05) aswell as the use of in vivo T cell depletion (p=0.003). The only factor observed to determine relapse risk between 3 and 6 months post-transplant was the presence at diagnosis of adverse risk cytogenetics (p=0.04). In patients who relapsed between 6 and 12 months post-transplant more than one course of chemotherapy to achieve CR1 (p=0.02), adverse risk cytogenetics (p=0.05) and FLT3 ITD positivity (p=0.00002) all predicted for relapse. Finally only CMV positivity predicted for relapse risk for more than 12 months post-transplant (p=0.05). This study confirms the importance of factors previously demonstrated to increase the overall relapse risk in patients allografted for AML. Our data also demonstrate a complex interaction of disease specific and transplant factors contributing to the kinetics of disease recurrence at different times post-transplant. In addition to identifying the occurrence of a dynamic interplay between tumor biology and transplant factors in determining the pathobiology of disease relapse post-transplant the results of this analysis can be used to assist in the design of novel strategies with specific reference to the timing of post-transplant intervention. Disclosures No relevant conflicts of interest to declare.
APA, Harvard, Vancouver, ISO, and other styles
21

Smart, Alicia, Theodore S. Hong, Natasa Petkovska, et al. "Hypofractionated radiation therapy for unresectable/locally recurrent intrahepatic cholangiocarcinoma." Journal of Clinical Oncology 37, no. 4_suppl (2019): 412. http://dx.doi.org/10.1200/jco.2019.37.4_suppl.412.

Full text
Abstract:
412 Background: Our objective was to evaluate outcomes for patients with unresectable/locally recurrent intrahepatic cholangiocarcinoma (ICC) treated with hypofractionated proton or photon radiation therapy (HF-RT). Methods: We retrospectively identified 66 patients with ICC who were treated with HF-RT from 2008-18. 51 patients had intrahepatic disease only, and 15 patients had extrahepatic disease at time of RT but received RT for biliary control. Median age at RT was 76 years (range: 30-92), including 27 patients (41%) ≥ 80 years. Median RT dose was 58.05 Gy (range: 37.5-67.5), delivered in 15 daily fractions. 32 patients received proton RT, and 34 patients received photon RT. Rates of local control (LC), progression-free survival (PFS), and overall survival (OS) were calculated by the Kaplan-Meier method. Univariate and multivariate analyses were conducted using the Cox proportional hazards method. For multivariate analyses, variables with p < 0.5 on univariate analysis were evaluated by backwards selection. Results: Median follow-up times from diagnosis and RT start were 21 and 14 months, respectively. In total, 5 patients (7.6%) developed local failure. Only 1 patient developed isolated local failure. The 2-yr outcomes were 93% LC, 37% PFS, and 55% OS. Among the 51 patients treated with definitive intent, the 2-yr LC was 96%, PFS 35%, OS 60%. Receipt of protons was significantly associated with younger age (p = 0.02), but not gender, race, ECOG status, metastatic disease at presentation, mean liver dose, cumulative GTV, or number of lesions. There were no significant predictors of LC or PFS, including RT dose. On UVA for OS, younger age, female gender, prior chemotherapy, prior surgery, and proton RT were associated with improved OS (p < 0.05). On MVA, female gender (HR: 0.33, p = 0.001), prior chemotherapy (HR: 0.38, p = 0.002), and proton vs. photon RT (HR: 0.50, p = 0.05) remained significantly associated with OS. Conclusions: HF-RT yields high rates of local control and is an effective modality to optimize biliary control for unresectable/locally recurrent IC. HF-RT should be considered for elderly patients who are considered medically inoperable. Proton RT and chemotherapy may further improve outcomes.
APA, Harvard, Vancouver, ISO, and other styles
22

Shimizu, Hiroki, Ryousuke Yamashita, Takuya Hashiguchi, Tasuku Miyata, and Yuuma Tamaru. "Square Layout Four-Point Method for Two-Dimensional Profile Measurement and Self-Calibration Method of Zero-Adjustment Error." International Journal of Automation Technology 12, no. 5 (2018): 707–13. http://dx.doi.org/10.20965/ijat.2018.p0707.

Full text
Abstract:
An on-machine measurement method, called the square-layout four-point (SLFP) method with angle compensation, for evaluating two-dimensional (2-D) profiles of flat machined surfaces is proposed. In this method, four displacement sensors are arranged in a square and mounted to the scanning table of a 2-D stage. For measuring the 2-D profile of a target plane, height data corresponding to all measuring points are acquired by means of the raster scanning motion. At the same time, pitching data of the first primary scan line and rolling data of the first subsidiary scan line are monitored by means of two auto-collimators to compensate for major profile errors that arise out of the posture error. Use of the SLFP method facilitates connection of the results of straightness-measurements results obtained for each scanning line by using two additional sensors and rolling data of the first subsidiary scan line. Specifically, the height of a measuring point is calculated by means of a recurrence equation using three predetermined height data for adjacent points in conjunction with data acquired by the four displacement sensors. Results of the numerical simulation performed in this study demonstrate higher efficiency of the SLFP method with angle compensation. During actual measurement, however, it is difficult to perfectly align inline the origin height of each displacement sensor. With regard to the SLFP method, zero-adjustment error is defined as the relative height of a sensor’s origin with respect to the plane comprising origins of the other three sensors. This error accumulates in proportion to number of times the recurrence equation is applied. Simulation results containing the zero-adjustment error demonstrate that accumulation of the said error results in unignorable distortion of measurement results. Therefore, a new self-calibration method for the zero-adjustment error has been proposed. During 2-D profile measurement, two different calculation paths – the raster scan path and orthogonal path – can be used to determine the height of a measurement point. Although heights determined through use of the two paths must ideally be equal, they are observed to be different because accumulated zero-adjustment errors for the two paths are different. In view of this result, the zero-adjustment error can be calculated backwards and calibrated. Validity of the calibration method has been confirmed via simulations and experiments.
APA, Harvard, Vancouver, ISO, and other styles
23

Losidis, Sotirios. "Covariance between the forward recurrence time and the number of renewals." Modern Stochastics: Theory and Applications, December 15, 2021, 1–16. http://dx.doi.org/10.15559/21-vmsta194.

Full text
Abstract:
Recurrence times and the number of renewals in $(0,t]$ are fundamental quantities in renewal theory. Firstly, it is proved that the upper orthant order for the pair of the forward and backward recurrence times may result in NWUC (NBUC) interarrivals. It is also demonstrated that, under DFR interarrival times, the backward recurrence time is smaller than the forward recurrence time in the hazard rate order. Lastly, the sign of the covariance between the forward recurrence time and the number of renewals in $(0,t]$ at a fixed time point t and when $t\to \infty $ is studied assuming that the interarrival distribution belongs to certain ageing classes.
APA, Harvard, Vancouver, ISO, and other styles
24

Losidis, Sotirios, Konstadinos Politis, and Georgios Psarrakos. "Bivariate dependence, stochastic orders and conditional tails of the recurrence times in a renewal process." Modern Stochastics: Theory and Applications, 2024, 1–15. http://dx.doi.org/10.15559/24-vmsta266.

Full text
Abstract:
The structure of dependence between the forward and the backward recurrence times in a renewal process is considered. Monotonicity properties, as a function of time, for the tail of the bivariate distribution for the recurrence times are discussed, as well as their link with aging properties of the interarrival distribution F. A necessary and sufficient condition for the renewal function to be concave is also obtained. Finally, some properties of the conditional tail for one of the two recurrence times, given some information on the other, are studied. The results are illustrated by some numerical examples.
APA, Harvard, Vancouver, ISO, and other styles
25

Pasricha, Puneet, and Dharmaraja Selvamuthu. "A Markov regenerative process with recurrence time and its application." Financial Innovation 7, no. 1 (2021). http://dx.doi.org/10.1186/s40854-021-00255-z.

Full text
Abstract:
AbstractThis study proposes a non-homogeneous continuous-time Markov regenerative process with recurrence times, in particular, forward and backward recurrence processes. We obtain the transient solution of the process in the form of a generalized Markov renewal equation. A distinguishing feature is that Markov and semi-Markov processes result as special cases of the proposed model. To model the credit rating dynamics to demonstrate its applicability, we apply the proposed stochastic process to Standard and Poor’s rating agency’s data. Further, statistical tests confirm that the proposed model captures the rating dynamics better than the existing models, and the inclusion of recurrence times significantly impacts the transition probabilities.
APA, Harvard, Vancouver, ISO, and other styles
26

Chadjiconstantinidis, Stathis, and Konstadinos Politis. "Bounds for the distribution and moments of the forward and backward recurrence times in a renewal process." Journal of Computational and Applied Mathematics, July 2024, 116166. http://dx.doi.org/10.1016/j.cam.2024.116166.

Full text
APA, Harvard, Vancouver, ISO, and other styles
27

Xu, Chuang, Mads Christian Hansen, and Carsten Wiuf. "Full classification of dynamics for one-dimensional continuous-time Markov chains with polynomial transition rates." Advances in Applied Probability, September 12, 2022, 1–35. http://dx.doi.org/10.1017/apr.2022.20.

Full text
Abstract:
Abstract This paper provides a full classification of the dynamics for continuous-time Markov chains (CTMCs) on the nonnegative integers with polynomial transition rate functions and without arbitrary large backward jumps. Such stochastic processes are abundant in applications, in particular in biology. More precisely, for CTMCs of bounded jumps, we provide necessary and sufficient conditions in terms of calculable parameters for explosivity, recurrence versus transience, positive recurrence versus null recurrence, certain absorption, and implosivity. Simple sufficient conditions for exponential ergodicity of stationary distributions and quasi-stationary distributions as well as existence and nonexistence of moments of hitting times are also obtained. Similar simple sufficient conditions for the aforementioned dynamics together with their opposite dynamics are established for CTMCs with unbounded forward jumps. Finally, we apply our results to stochastic reaction networks, an extended class of branching processes, a general bursty single-cell stochastic gene expression model, and population processes, none of which are birth–death processes. The approach is based on a mixture of Lyapunov–Foster-type results, the classical semimartingale approach, and estimates of stationary measures.
APA, Harvard, Vancouver, ISO, and other styles
28

Peshwe, Krithika, Ya-Huei Li, nida akram, Amre Nouh, and Yan Hou. "Abstract TP334: Racial Disparities in Functional Outcomes and Stroke Recurrence in Young Patients with Ischemic Stroke." Stroke 56, Suppl_1 (2025). https://doi.org/10.1161/str.56.suppl_1.tp334.

Full text
Abstract:
Introduction: Studies have reported racial disparities in acute stroke treatment and follow-up care in young patients which lead to less desirable outcomes for minorities. This study aimed to identify potentially modifiable factors for better stroke treatment and prevention in minority populations. Methods: Young patients aged 18-50 years who were admitted with ischemic stroke during 09/2016-12/2022 were retrospectively identified and stratified as non-Hispanic White (WH), non-Hispanic Black (BL), and Hispanic (HS). Racial differences in risk factors, stroke etiology, acute intervention, and follow-ups were examined using Chi-square and Kruskal-Wallis tests as appropriate. Cumulative probabilities of stroke recurrence were estimated using the Kaplan-Meier (KM) method and tested with the Log-rank (Mantel-Cox) test. A logistic regression was used to evaluate the odds ratio of favorable functional outcomes (mRS ≤2) by 90 days. A backward stepwise Cox regression was conducted to identify predictors of stroke recurrence reported as hazard ratio (HR) and a 95% confidence interval (CI). Results: A total of 318 patients were identified with a median age of 43 and 57.5% male, covering 57.2% WH, 22.3% BL, and 20.4% HS. Compared to WH, more BL and HS were comorbid with diabetes, hypertension, and prior stroke (p<0.05). The rates of other risk factors did not vary by race. The distribution of stroke etiologies and rate of acute interventions (IV tPA, thrombectomy) were similar among the three. After discharge, 77.3% of young patients had ≥1 follow-ups at stroke clinic. The total number of stroke clinic follow-ups were similar among racial groups. At 90 days, 89.6% of patients achieved mRS≤2; the odds of having this favorable functional outcome were similar among racial groups ( p =0.207). The KM curve indicates that the first-year risks of stroke recurrence were similar among racial groups and that a trend showed BL had the highest risk of recurrent strokes, followed by HS, and WH had the lowest risk in 1-3 year follow up. Yet, these differences were not statistically significant ( p =0.056. BL was found to have 2.7 times higher risk to have a recurrent stroke than whites (HR: 3.7; 95% CI: 1.4-10.1; p=0.01). Conclusions: Findings highlighted high prevalence of hypertension and diabetes in young BL and HS and a higher risk of recurrent stroke in young BL, suggesting tailored interventions for comorbidities are urged for better stroke prevention in minorities.
APA, Harvard, Vancouver, ISO, and other styles
29

Michelitsch, Thomas M., Giuseppe D’Onofrio, Federico Polito, and Alejandro P. Riascos. "Random walks with stochastic resetting in complex networks: A discrete-time approach." Chaos: An Interdisciplinary Journal of Nonlinear Science 35, no. 1 (2025). https://doi.org/10.1063/5.0238517.

Full text
Abstract:
We consider a discrete-time Markovian random walk with resets on a connected undirected network. The resets, in which the walker is relocated to randomly chosen nodes, are governed by an independent discrete-time renewal process. Some nodes of the network are target nodes, and we focus on the statistics of first hitting of these nodes. In the non-Markov case of the renewal process, we consider both light- and fat-tailed inter-reset distributions. We derive the propagator matrix in terms of discrete backward recurrence time probability density functions, and in the light-tailed case, we show the existence of a non-equilibrium steady state. In order to tackle the non-Markov scenario, we derive a defective propagator matrix, which describes an auxiliary walk characterized by killing the walker as soon as it hits target nodes. This propagator provides the information on the mean first passage statistics to the target nodes. We establish sufficient conditions for ergodicity of the walk under resetting. Furthermore, we discuss a generic resetting mechanism for which the walk is non-ergodic. Finally, we analyze inter-reset time distributions with infinite mean where we focus on the Sibuya case. We apply these results to study the mean first passage times for Markovian and non-Markovian (Sibuya) renewal resetting protocols in realizations of Watts–Strogatz and Barabási–Albert random graphs. We show nontrivial behavior of the dependence of the mean first passage time on the proportions of the relocation nodes, target nodes, and of the resetting rates. It turns out that, in the large-world case of the Watts–Strogatz graph, the efficiency of a random searcher particularly benefits from the presence of resets.
APA, Harvard, Vancouver, ISO, and other styles
30

Li, Kang, Yi Song, Ling Qin, et al. "A CpG Methylation Signature as a Potential Marker for Early Diagnosis of Hepatocellular Carcinoma From HBV-Related Liver Disease Using Multiplex Bisulfite Sequencing." Frontiers in Oncology 11 (October 20, 2021). http://dx.doi.org/10.3389/fonc.2021.756326.

Full text
Abstract:
BackgroundAberrant methylation of CpG sites served as an epigenetic marker for building diagnostic, prognostic, and recurrence models for hepatocellular carcinoma (HCC).MethodsUsing Illumina 450K and EPIC Beadchip, we identified 34 CpG sites in peripheral blood mononuclear cell (PBMC) DNA that were differentially methylated in early HCC versus HBV-related liver diseases (HBVLD). We employed multiplex bisulfite sequencing (MBS) based on next-generation sequencing (NGS) to measure methylation of 34 CpG sites in PBMC DNA from 654 patients that were divided into a training set (n = 442) and a test set (n = 212). Using the training set, we selected and built a six-CpG-scorer (namely, cg14171514, cg07721852, cg05166871, cg18087306, cg05213896, and cg18772205), applying least absolute shrinkage and selection operator (LASSO) regression. We performed multivariable analyses of four candidate risk predictors (namely, six-CpG-scorer, age, sex, and AFP level), using 20 times imputation of missing data, non-linearly transformed, and backwards feature selection with logistic regression. The final model’s regression coefficients were calculated according to “Rubin’s Rules”. The diagnostic accuracy of the model was internally validated with a 10,000 bootstrap validation dataset and then applied to the test set for validation.ResultsThe area under the receiver operating characteristic curve (AUROC) of the model was 0.81 (95% CI, 0.77–0.85) and it showed good calibration and decision curve analysis. Using enhanced bootstrap validation, adjusted C-statistics and adjusted Brier score were 0.809 and 0.199, respectively. The model also showed an AUROC value of 0.84 (95% CI 0.79–0.88) of diagnosis for early HCC in the test set.ConclusionsOur model based on the six-CpG-scorer was a reliable diagnosis tool for early HCC from HBVLD. The usage of the MBS method can realize large-scale detection of CpG sites in clinical diagnosis of early HCC and benefit the majority of patients.
APA, Harvard, Vancouver, ISO, and other styles
31

Cheng, Lin, Zezhou Feng, Zhaonan Hao, Minmin Si, Rui Yuan, and Zhiyuan Feng. "Molar distalization in orthodontics: a bibliometric analysis." Clinical Oral Investigations 28, no. 2 (2024). http://dx.doi.org/10.1007/s00784-024-05520-w.

Full text
Abstract:
Abstract Objectives The study endeavors to undertake a bibliometric analysis on molar distalization, with the objective of illuminating its evolutionary trajectory, current status, and prognosticating future research hotspots and trends. Material and methods A comprehensive exploration of the literature on molar distalization was carried out by conducting a search in the Web of Science (WOS) core database of the University of Hong Kong Electronic Library. The search for topic terms employed included “molar distalization,” “molar distalisation,” “move molar distally,” “molar distal movement,” and “molar backwards.” The search results were subsequently subjected to meticulous analysis using CiteSpace software. This analysis encompassed various facets such as the citation count; the geographical distribution of the countries, institutions, and journals responsible for publishing the articles; the distribution of the authors; the utilization of keywords within the articles; and the analysis of references. Results A total of 516 articles were included in the analysis. The top 5 countries in terms of the number of published papers were the United States (USA), South Korea, Turkey, Italy, and Germany, and the top 5 institutions in terms of the number of published papers were Kyung Hee University, A.T. Still University of Health Sciences, Catholic University of Korea, Seoul St. Mary’s Hospital, and Universidade de Sao Paulo. The top 5 authors in terms of the number of published papers were Park, Kook, Bayome, Janson, and Lee. There was little cooperation overall. The top 3 journals in terms of the most published related articles were all orthodontic-related journals. After molar distalization and anchorage, the most frequently used keywords were distalization, movement, and pendulum appliance. Kinzinger GSM is the most frequently cited author in references, and one of his articles also has the highest centrality score in references. Conclusions As the tides of time shift and scholars display an ever-growing dedication to unraveling the intricacies of this therapeutic modality, the realm of molar distalization has undergone notable advancements in technology. Initially, the traditional appliance suffered from aesthetic drawbacks and discomfort. However, contemporary iterations of the appliance have transcended these limitations, boasting enhanced elegance and convenience while concurrently elevating their efficacy. Nevertheless, limitations of current appliances, including their durability and propensity for recurrence post-treatment, continue to necessitate further advancement. Hence, the ongoing scientific inquiry aims to delve deeper into refining treatment modalities and fabricating cutting-edge appliances within this realm. Clinical relevance. This study holds the potential to significantly enhance the ability of orthodontists to devise treatment protocols and offer state-of-the-art clinical recommendations, thereby empowering them to deliver advanced and refined orthodontic interventions.
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography