Browsing by Subject "Regression analysis"

Now showing items 21-40 of 44

    • Article  

      Non-Parametric Sequential Estimation of a Regression Function Based on Dependent Observations 

      Politis, Dimitris Nicolas; Vasiliev, V. A. (2013)
      This article presents a sequential estimation procedure for an unknown regression function. Observed regressors and noises of the model are supposed to be dependent and form sequences of dependent numbers. Two types of ...
    • Article  

      Nonlinear Poisson autoregression 

      Fokianos, Konstantinos; Tjøstheim, D. (2012)
      We study statistical properties of a class of non-linear models for regression analysis of count time series. Under mild conditions, it is shown that a perturbed version of the model is geometrically ergodic and possesses ...
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      Nonparametric Maximum Entropy 

      Politis, Dimitris Nicolas (1993)
      The standard maximum entropy method of Burg and the resulting autoregressive model has been widely applied for spectrum estimation and prediction. A generalization of the maximum entropy formalism in a nonparametric setting ...
    • Article  

      Nonparametric predictive regression 

      Kasparis, Ioannis; Andreou, Elena; Phillips, Peter C. B. (2015)
      A unifying framework for inference is developed in predictive regressions where the predictor has unknown integration properties and may be stationary or nonstationary. Two easily implemented nonparametric F-tests are ...
    • Article  

      Nonparametric regression estimation based on spatially inhomogeneous data: Minimax global convergence rates and adaptivity 

      Antoniadis, Anestis; Pensky, M.; Sapatinas, Theofanis (2014)
      We consider the nonparametric regression estimation problem of recovering an unknown response function f on the basis of spatially inhomogeneous data when the design points follow a known density g with a finite number of ...
    • Article  

      On comparing several spectral densities 

      Fokianos, Konstantinos; Savvides, A. (2008)
      We investigated the problem of testing equality among spectral densities of several independent stationary processes. Our main methodological contribution is the introduction of a novel semiparametric log-linear model that ...
    • Article  

      On efficient AR spectral estimation for long-range predictions 

      Karagrigoriou, Alex; Vonta, Filia (2005)
      This article discusses the concept of asymptotic efficiency from the frequency domain point of view making use of the direct method for multiple prediction. In particular, it is shown that with the use of a new autoregressive ...
    • Article  

      On the use of high frequency measures of volatility in MIDAS regressions 

      Andreou, Elena (2016)
      Many empirical studies link mixed data frequency variables such as low frequency macroeconomic or financial variables with high frequency financial indicators’ volatilities, especially within a predictive regression model ...
    • Article  

      Optimal testing for additivity in multiple nonparametric regression 

      Abramovich, F.; De Feis, I.; Sapatinas, Theofanis (2009)
      We consider the problem of testing for additivity in the standard multiple nonparametric regression model. We derive optimal (in the minimax sense) non- adaptive and adaptive hypothesis testing procedures for additivity ...
    • Article  

      Personality variables are associated with colorectal cancer patients' quality of life independent of psychological distress and disease severity 

      Paika, V.; Almyroudi, A.; Tomenson, B.; Creed, F.; Kampletsas, E. O.; Siafaka, V.; Gkika, S.; Mavreas, V.; Pavlidis, Nicholas; Hyphantis, T. (2010)
      Objective: The aim of the present study was to test whether psychological distress and personality variables are independently associated with health-related quality of life (HRQOL) in colorectal cancer patients, after ...
    • Article  

      Power divergence family of tests for categorical time series models 

      Fokianos, Konstantinos (2002)
      A fundamental issue that arises after fitting a regression model is that of testing the goodness of the fit. Our work brings together the power divergence family of goodness of fit tests and regression models for categorical ...
    • Article  

      Prediction of intrinsic viscosity in polymer-solvent combinations using a QSPR model 

      Afantitis, Antreas; Melagraki, G.; Sarimveis, H.; Koutentis, Panayiotis Andreas; Markopoulos, J.; Igglessi-Markopoulou, O. (2006)
      In this work, a linear quantitative structure-property relationship (QSPR) model is presented for the prediction of intrinsic viscosity in polymer solutions. The model was produced by using the multiple linear regression ...
    • Article  

      Prognostic factors influencing complete response to treatment and survival of patients with nasopharyngeal cancer 

      Kalogera-Fountzila, Anna; Kosmidis, Paraskevas A.; Bacoyiannis, Charalambos; Nicolaou, A.; Samantas, E.; Briassoulis, E. Ch; Pavlidis, Nicholas; Skarlos, Dimosthenis V.; Daniilidis, J.; Fountzilas, George (1998)
      The identification of prognostic factors influencing local control and survival of patients with nasopharyngeal cancer (NPC) might help in pointing out those patients who would probably benefit from primary treatment. A ...
    • Article  

      Prognostic significance of RACGAP1 mRNA expression in high-risk early breast cancer: A study in primary tumors of breast cancer patients participating in a randomized Hellenic Cooperative Oncology Group trial 

      Pliarchopoulou, K.; Kalogeras, K. T.; Kronenwett, R.; Wirtz, R. M.; Eleftheraki, A. G.; Batistatou, Anna; Bobos, M.; Soupos, N.; Polychronidou, G.; Gogas, H.; Samantas, E.; Christodoulou, C.; Makatsoris, T.; Pavlidis, Nicholas; Pectasides, Dimitrios; Fountzilas, George (2013)
      Purpose: RACGAP1 is a Rac GTPase-activating protein involved in cell growth regulation, cell transformation and metastasis. The aim of the present study was to explore the prognostic and/or predictive significance of RACGAP1 ...
    • Article  

      Prognostic variables in Greek patients with stage II breast cancer: A Hellenic Cooperative Oncology Group Study 

      Fountzilas, George; Vasilaros, S.; Koukouras, D.; Malamos, N.; Pectasides, Dimitrios; Adamou, A.; Nenopoulou, E.; Kiriakou, K.; Zouvani, I.; Katsohis, C.; Kappas, A. M.; Skopa, C.; Semoglou, C.; Fahantidis, E.; Konstantaras, C.; Vasilaki, E.; Economopoulos, T.; Bacoyiannis, Charalambos; Bafaloukos, Dimitrios; Razi, E. D.; Polichrnis, A.; Androulakis, G.; Papaioannou, T.; Pavlidis, Nicholas; Skarlos, Dimosthenis V.; Kosmidis, Paraskevas A. (1997)
      The independent effects of several patient, tumor and treatment-related prognostic factors on relapse-free survival (RFS) and overall survival (OS) were assessed by Cox multivariate regression analysis in 988 Greek patients ...
    • Article  

      Regression models with mixed sampling frequencies 

      Andreou, Elena; Ghysels, Eric; Kourtellos, Andros (2010)
      We study regression models that involve data sampled at different frequencies. We derive the asymptotic properties of the NLS estimators of such regression models and compare them with the LS estimators of a traditional ...
    • Article  

      Safety and efficacy of long-term statin treatment for cardiovascular events in patients with coronary heart disease and abnormal liver tests in the Greek Atorvastatin and Coronary Heart Disease Evaluation (GREACE) Study: a post-hoc analysis 

      Athyros, Vasilios G.; Tziomalos, Konstantinos; Gossios, Thomas D.; Griva, Theodora; Anagnostis, Panagiotis; Kargiotis, Konstantinos; Pagourelias, Efstathios D.; Theocharidou, Eleni; Karagiannis, Asterios; Mikhailidis, Dimitri P.; Basdekas, S.; Bouloukos, V.; Christaki, Eirini; Dimopoulou, S.; Hartamba, E.; Kakafika, A.; Kapousouzi, M.; Koumaras, H.; Mitsiou, E.; Papageorgiou, A.; Pehlivanidis, A.; Petridis, D.; Sekeri, Z.; Skaperdas, A.; Symeonidis, A. (2010)
      Long-term statin treatment reduces the frequency of cardiovascular events, but safety and efficacy in patients with abnormal liver tests is unclear. We assessed whether statin therapy is safe and effective for these patients ...
    • Article  

      Semiparametric approach to the one-way layout 

      Fokianos, Konstantinos; Qin, J.; Kedem, B.; Short, D. A. (2001)
      We consider m distributions in which the first m-1 are obtained by multiplicative exponential distortions of the mth distribution, which is a reference. The combined data from rn samples, one from each distribution, are ...
    • Article  

      Sensitivity analysis of a neural network used for the forecasting of electric power load 

      Neocleous, Costas K.; Papazoglou, Thales M.; Schizas, Christos N.; Stratakis, Dimitrios I. (1999)
      A feedforward multilayer neural network has been used for the estimation of the four-hour-ahead electric load in Power Plant in the island of Crete. An attempt was made to use few variables for the input vector, while ...
    • Article  

      Spatial characteristics of urinary BTEX concentrations in the general population 

      Tsangari, Xanthi; Andrianou, Xanthi D.; Agapiou, Agapios; Mochalski, Paweł; Makris, Konstantinos C. (2017)
      Benzene, toluene, ethylbenzene, o-, m-, and p-xylenes (BTEX) are ubiquitous outdoor and indoor air pollutants associated with both environmental and health effects. The objective of this exploratory study was to determine ...