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Ning Ning

Bio: Ning Ning is an academic researcher from University of Michigan. The author has contributed to research in topics: Time series & Tree (data structure). The author has an hindex of 7, co-authored 25 publications receiving 122 citations. Previous affiliations of Ning Ning include University of Washington & University of California, Santa Barbara.

Papers
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Journal Article•DOI•
TL;DR: In this article, a multivariate structural model for time series with a cyclical component is proposed, which can handle large variations in the short term, which may be caused by external shocks.
Abstract: This paper deals with inference and prediction for multiple correlated time series, where one also has the choice of using a candidate pool of contemporaneous predictors for each target series. Starting with a structural model for time series, we use Bayesian tools for model fitting, prediction and feature selection, thus extending some recent works along these lines for the univariate case. The Bayesian paradigm in this multivariate setting helps the model avoid overfitting, as well as captures correlations among multiple target time series with various state components. The model provides needed flexibility in selecting a different set of components and available predictors for each target series. The cyclical component in the model can handle large variations in the short term, which may be caused by external shocks. Extensive simulations were run to investigate properties such as estimation accuracy and performance in forecasting. This was followed by an empirical study with one-step-ahead prediction on the max log return of a portfolio of stocks that involve four leading financial institutions. Both the simulation studies and the extensive empirical study confirm that this multivariate model outperforms three other benchmark models, viz. a model that treats each target series as independent, the autoregressive integrated moving average model with regression (ARIMAX), and the multivariate ARIMAX (MARIMAX) model.

29 citations

Journal Article•
TL;DR: This model is the first one that successfully incorporated the online text mining to an advanced multivariate Bayesian machine learning time series model, which opens the door of applying both text mining and machine learning simultaneously in modern quantitative finance research.
Abstract: Author(s): Jammalamadaka, SR; Qiu, J; Ning, N | Abstract: In this paper, we provide methods for creatively incorporating information from financial news and Twitter feeds into predicting the prices of a portfolio of stocks, using the framework of the Multivariate Bayesian Structural Time Series (MBSTS) model. MBSTS is a Bayesian machine learning model designed to capture correlations among multiple target time series, while using a number of contemporaneous predictors. As an illustration of the current model, we use data on two leading online commerce companies, namely Amazon and eBay, and run extensive empirical experiments to examine which if any, text mining predictors would add to the predictability of a stock price. Evaluation of competing models such as the autoregressive integrated moving average (ARIMA) model, and the recurrent neural network (RNN) model with long short term memory (LSTM), in terms of their performances with respect to cumulative one-step-ahead forecast errors with and without sentimental predictors, were carried out. Our contributions are threefold: Firstly, our model is the first one that successfully incorporated the online text mining to an advanced multivariate Bayesian machine learning time series model, which opens the door of applying both text mining and machine learning simultaneously in modern quantitative finance research; Secondly, under the presence of both modern and classical predictors in both fundamental and technical sense, the polarity of news still adds on a complementary effect; Thirdly, we discover that all models under investigation with sentimental predictors do outperform models without these sentimental predictors, and the MBSTS model with sentimental predictors outperforms all the other models.

26 citations

Journal Article•DOI•
TL;DR: Numerical experiments show that this approximation procedure performs very well, even in the regime of moderately slow varying stochastic bounds, which gives a tremendous computational advantage.
Abstract: In this paper, we study a class of uncertain volatility models with stochastic bounds. Like in the regular uncertain volatility models, we know only that volatility stays between two bounds, but in...

16 citations

Journal Article•DOI•
TL;DR: Extensive analyses on both simulated data and empirical data indicate that the MBTS model is able to, cover the true values of regression coefficients in 90% credible intervals, select the most important predictors, and boost the prediction accuracy with higher correlation in absolute value of the target series.
Abstract: In this paper, we perform multivariate time series analysis from a Bayesian machine learning perspective through the proposed multivariate Bayesian time series (MBTS) model. The multivariate structure and the Bayesian framework allow the model to take advantage of the association structure among target series, select important features, and train the data-driven model at the same time. Extensive analyses on both simulated data and empirical data indicate that the MBTS model is able to, cover the true values of regression coefficients in 90% credible intervals, select the most important predictors, and boost the prediction accuracy with higher correlation in absolute value of the target series, and consistently yield superior performance over the univariate Bayesian structural time series (BSTS) model, the autoregressive integrated moving average with regression (ARIMAX) model, and the multivariate ARIMAX (MARIMAX) model, in one-step-ahead forecast and ten-steps-ahead forecast.

16 citations

Journal Article•DOI•
TL;DR: In this paper, the authors explore whether spatial knowledge spillovers among regions exist and whether these spillovers promote regional innovative activities and whether external knowledge spillover affects the evolution of regional innovations in the long run.
Abstract: This paper extends endogenous economic growth models to incorporate knowledge externality. We explore whether spatial knowledge spillovers among regions exist, whether spatial knowledge spillovers promote regional innovative activities, and whether external knowledge spillovers affect the evolution of regional innovations in the long run. We empirically verify the theoretical results through applying spatial statistics and econometric models in the analysis of panel data of 31 regions in China. An accurate estimate of the range of knowledge spillovers is achieved and the convergence of regional knowledge growth rate is found, with clear evidences that developing regions benefit more from external knowledge spillovers than developed regions.

15 citations


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TL;DR: In this paper, the authors provide a unified and comprehensive theory of structural time series models, including a detailed treatment of the Kalman filter for modeling economic and social time series, and address the special problems which the treatment of such series poses.
Abstract: In this book, Andrew Harvey sets out to provide a unified and comprehensive theory of structural time series models. Unlike the traditional ARIMA models, structural time series models consist explicitly of unobserved components, such as trends and seasonals, which have a direct interpretation. As a result the model selection methodology associated with structural models is much closer to econometric methodology. The link with econometrics is made even closer by the natural way in which the models can be extended to include explanatory variables and to cope with multivariate time series. From the technical point of view, state space models and the Kalman filter play a key role in the statistical treatment of structural time series models. The book includes a detailed treatment of the Kalman filter. This technique was originally developed in control engineering, but is becoming increasingly important in fields such as economics and operations research. This book is concerned primarily with modelling economic and social time series, and with addressing the special problems which the treatment of such series poses. The properties of the models and the methodological techniques used to select them are illustrated with various applications. These range from the modellling of trends and cycles in US macroeconomic time series to to an evaluation of the effects of seat belt legislation in the UK.

4,252 citations

01 Jan 2009
TL;DR: This volume provides a systematic treatment of stochastic optimization problems applied to finance by presenting the different existing methods: dynamic programming, viscosity solutions, backward stochastically differential equations, and martingale duality methods.
Abstract: Stochastic optimization problems arise in decision-making problems under uncertainty, and find various applications in economics and finance. On the other hand, problems in finance have recently led to new developments in the theory of stochastic control. This volume provides a systematic treatment of stochastic optimization problems applied to finance by presenting the different existing methods: dynamic programming, viscosity solutions, backward stochastic differential equations, and martingale duality methods. The theory is discussed in the context of recent developments in this field, with complete and detailed proofs, and is illustrated by means of concrete examples from the world of finance: portfolio allocation, option hedging, real options, optimal investment, etc. This book is directed towards graduate students and researchers in mathematical finance, and will also benefit applied mathematicians interested in financial applications and practitioners wishing to know more about the use of stochastic optimization methods in finance.

759 citations

01 Jan 2016
TL;DR: The stochastic differential equations and applications is universally compatible with any devices to read, and an online access to it is set as public so you can get it instantly.
Abstract: stochastic differential equations and applications is available in our digital library an online access to it is set as public so you can get it instantly. Our books collection saves in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Kindly say, the stochastic differential equations and applications is universally compatible with any devices to read.

741 citations

Journal Article•DOI•
TL;DR: In this article, the convergence of Distri butions of Likelihood Ratio has been discussed, and the authors propose a method to construct a set of limit laws for Likelihood Ratios.
Abstract: 1 Introduction.- 2 Experiments, Deficiencies, Distances v.- 2.1 Comparing Risk Functions.- 2.2 Deficiency and Distance between Experiments.- 2.3 Likelihood Ratios and Blackwell's Representation.- 2.4 Further Remarks on the Convergence of Distri butions of Likelihood Ratios.- 2.5 Historical Remarks.- 3 Contiguity - Hellinger Transforms.- 3.1 Contiguity.- 3.2 Hellinger Distances, Hellinger Transforms.- 3.3 Historical Remarks.- 4 Gaussian Shift and Poisson Experiments.- 4.1 Introduction.- 4.2 Gaussian Experiments.- 4.3 Poisson Experiments.- 4.4 Historical Remarks.- 5 Limit Laws for Likelihood Ratios.- 5.1 Introduction.- 5.2 Auxiliary Results.- 5.2.1 Lindeberg's Procedure.- 5.2.2 Levy Splittings.- 5.2.3 Paul Levy's Symmetrization Inequalities.- 5.2.4 Conditions for Shift-Compactness.- 5.2.5 A Central Limit Theorem for Infinitesimal Arrays.- 5.2.6 The Special Case of Gaussian Limits.- 5.2.7 Peano Differentiable Functions.- 5.3 Limits for Binary Experiments.- 5.4 Gaussian Limits.- 5.5 Historical Remarks.- 6 Local Asymptotic Normality.- 6.1 Introduction.- 6.2 Locally Asymptotically Quadratic Families.- 6.3 A Method of Construction of Estimates.- 6.4 Some Local Bayes Properties.- 6.5 Invariance and Regularity.- 6.6 The LAMN and LAN Conditions.- 6.7 Additional Remarks on the LAN Conditions.- 6.8 Wald's Tests and Confidence Ellipsoids.- 6.9 Possible Extensions.- 6.10 Historical Remarks.- 7 Independent, Identically Distributed Observations.- 7.1 Introduction.- 7.2 The Standard i.i.d. Case: Differentiability in Quadratic Mean.- 7.3 Some Examples.- 7.4 Some Nonparametric Considerations.- 7.5 Bounds on the Risk of Estimates.- 7.6 Some Cases Where the Number of Observations Is Random.- 7.7 Historical Remarks.- 8 On Bayes Procedures.- 8.1 Introduction.- 8.2 Bayes Procedures Behave Nicely.- 8.3 The Bernstein-von Mises Phenomenon.- 8.4 A Bernstein-von Mises Result for the i.i.d. Case.- 8.5 Bayes Procedures Behave Miserably.- 8.6 Historical Remarks.- Author Index.

483 citations