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Residual Value Forecasting Using Asymmetric Cost Functions

arXiv.org Machine Learning

Leasing is a popular channel to market new cars. Pricing a leasing contract is complicated because the leasing rate embodies an expectation of the residual value of the car after contract expiration. To aid lessors in their pricing decisions, the paper develops resale price forecasting models. A peculiarity of the leasing business is that forecast errors entail different costs. Identifying effective ways to address this characteristic is the main objective of the paper. More specifically, the paper contributes to the literature through i) consolidating and integrating previous work in forecasting with asymmetric cost of error functions, ii) systematically evaluating previous approaches and comparing them to a new approach, and iii) demonstrating that forecasting with asymmetric cost of error functions enhances the quality of decision support in car leasing. For example, under the assumption that the costs of overestimating resale prices is twice that of the opposite error, incorporating corresponding cost asymmetry into forecast model development reduces decision costs by about eight percent, compared to a standard forecasting model. Higher asymmetry produces even larger improvements.


Submodular Variational Inference for Network Reconstruction

arXiv.org Machine Learning

In real-world and online social networks, individuals receive and transmit information in real time. Cascading information transmissions (e.g. phone calls, text messages, social media posts) may be understood as a realization of a diffusion process operating on the network, and its branching path can be represented by a directed tree. The process only traverses and thus reveals a limited portion of the edges. The network reconstruction/inference problem is to infer the unrevealed connections. Most existing approaches derive a likelihood and attempt to find the network topology maximizing the likelihood, a problem that is highly intractable. In this paper, we focus on the network reconstruction problem for a broad class of real-world diffusion processes, exemplified by a network diffusion scheme called respondent-driven sampling (RDS). We prove that under realistic and general models of network diffusion, the posterior distribution of an observed RDS realization is a Bayesian log-submodular model.We then propose VINE (Variational Inference for Network rEconstruction), a novel, accurate, and computationally efficient variational inference algorithm, for the network reconstruction problem under this model. Crucially, we do not assume any particular probabilistic model for the underlying network. VINE recovers any connected graph with high accuracy as shown by our experimental results on real-life networks.


WWE Great Balls Of Fire 2017: Live Stream Info, Start Time, Match Card For 'Monday Night Raw' PPV

International Business Times

Four WWE superstars are unofficially in the running to be in the main event of SummerSlam 2017 on Aug. 20. The biggest match since WrestleMania 33 will be determined Sunday night at Great Balls of Fire 2017, WWE's next "Monday Night Raw" pay-per-view. Great Balls of Fire 2017 is scheduled to start at 8 p.m. EDT, and the pre-show gets underway at 7:30 p.m. EDT. Ordering the event on PPV costs $54.99, but fans can also watch the event with a live stream on the WWE Network. A subscription to the network costs $9.99 per month, though new subscribers get the first month free.


UFC 213 Betting Odds, PPV Info For Amanda Nunes vs. Valentina Shevchenko And Entire Fight Card

International Business Times

For the first time in 2017, Amanda Nunes will defend her UFC women's bantamweight championship. She'll put the belt on the line Saturday night in the main event of UFC 213 in Las Vegas. Nunes hasn't stepped inside the octagon since she needed 48 seconds to defeat Ronda Rousey on Dec. 30. She headlined the pay-per-view in her previous two title fights, and it'll cost fans $69.99 to order Saturday's fight. The PPV starts at 10 p.m. EDT, though fans can watch the event with a live stream online at ufc.tv for $59.99.


Estimating network edge probabilities by neighborhood smoothing

arXiv.org Machine Learning

The estimation of probabilities of network edges from the observed adjacency matrix has important applications to predicting missing links and network denoising. It has usually been addressed by estimating the graphon, a function that determines the matrix of edge probabilities, but this is ill-defined without strong assumptions on the network structure. Here we propose a novel computationally efficient method, based on neighborhood smoothing to estimate the expectation of the adjacency matrix directly, without making the structural assumptions that graphon estimation requires. The neighborhood smoothing method requires little tuning, has a competitive mean-squared error rate, and outperforms many benchmark methods on link prediction in simulated and real networks.


Dr.VAE: Drug Response Variational Autoencoder

arXiv.org Machine Learning

We present two deep generative models based on Variational Autoencoders to improve the accuracy of drug response prediction. Our models, Perturbation Variational Autoencoder and its semi-supervised extension, Drug Response Variational Autoencoder (Dr.VAE), learn latent representation of the underlying gene states before and after drug application that depend on: (i) drug-induced biological change of each gene and (ii) overall treatment response outcome. Our VAE-based models outperform the current published benchmarks in the field by anywhere from 3 to 11% AUROC and 2 to 30% AUPR. In addition, we found that better reconstruction accuracy does not necessarily lead to improvement in classification accuracy and that jointly trained models perform better than models that minimize reconstruction error independently.


Online Rules for Control of False Discovery Rate and False Discovery Exceedance

arXiv.org Machine Learning

Multiple hypothesis testing is a core problem in statistical inference and arises in almost every scientific field. Given a set of null hypotheses $\mathcal{H}(n) = (H_1,\dotsc, H_n)$, Benjamini and Hochberg introduced the false discovery rate (FDR), which is the expected proportion of false positives among rejected null hypotheses, and proposed a testing procedure that controls FDR below a pre-assigned significance level. Nowadays FDR is the criterion of choice for large scale multiple hypothesis testing. In this paper we consider the problem of controlling FDR in an "online manner". Concretely, we consider an ordered --possibly infinite-- sequence of null hypotheses $\mathcal{H} = (H_1,H_2,H_3,\dots )$ where, at each step $i$, the statistician must decide whether to reject hypothesis $H_i$ having access only to the previous decisions. This model was introduced by Foster and Stine. We study a class of "generalized alpha-investing" procedures and prove that any rule in this class controls online FDR, provided $p$-values corresponding to true nulls are independent from the other $p$-values. (Earlier work only established mFDR control.) Next, we obtain conditions under which generalized alpha-investing controls FDR in the presence of general $p$-values dependencies. Finally, we develop a modified set of procedures that also allow to control the false discovery exceedance (the tail of the proportion of false discoveries). Numerical simulations and analytical results indicate that online procedures do not incur a large loss in statistical power with respect to offline approaches, such as Benjamini-Hochberg.


WWE Great Balls Of Fire 2017: Predictions, Match Card For 'Monday Night Raw' PPV

International Business Times

SummerSlam is still more than a month away, but WWE has its biggest pay-per-view since WrestleMania 33 set for Sunday night. Great Balls of Fire 2017 features a stacked card with several intriguing matches. It'd be stunning to see Joe beat Lesnar and win his first title on the main roster. That doesn't mean it's not a highly anticipated match, and the build towards Sunday's main event has been better than any of Lesnar's recent feuds. Even if Joe does get pinned to end the PPV, he should find himself near the top of the card at SummerSlam because of what he's done in the weeks leading up to this WWE Universal Championship Match.


A Data Science Approach to Understanding Residential Water Contamination in Flint

arXiv.org Machine Learning

When the residents of Flint learned that lead had contaminated their water system, the local government made water-testing kits available to them free of charge. The city government published the results of these tests, creating a valuable dataset that is key to understanding the causes and extent of the lead contamination event in Flint. This is the nation's largest dataset on lead in a municipal water system. In this paper, we predict the lead contamination for each household's water supply, and we study several related aspects of Flint's water troubles, many of which generalize well beyond this one city. For example, we show that elevated lead risks can be (weakly) predicted from observable home attributes. Then we explore the factors associated with elevated lead. These risk assessments were developed in part via a crowd sourced prediction challenge at the University of Michigan. To inform Flint residents of these assessments, they have been incorporated into a web and mobile application funded by \texttt{Google.org}. We also explore questions of self-selection in the residential testing program, examining which factors are linked to when and how frequently residents voluntarily sample their water.


Employee turnover prediction and retention policies design: a case study

arXiv.org Machine Learning

Machine learning algorithms are often showcased in customer churn study. Applications in fields such as telecommunication or product marketing (gaming, insurance etc..)(see [1],[2] for a recent review) are multiple. The implementation of these methods in Customer Relationship Management is becoming the new norm, as improving customer retention yields superior business results. We argue that this type of techniques can easily be applied to employee turnover. Note that the employee turnover can actually be subdivided in 3 buckets: involuntary turnover (induced by the company), voluntary turnover (employee resignation) and retirements. Retirement and an involuntary turnover are out of the scope of this paper.