Space-Time Modeling of Timber Prices

A space-time econometric model was developed for pine sawtimber timber prices of 21 geographically contiguous regions in the southern United States. The correlations between prices in neighboring regions helped predict future prices. The impulse response analysis showed that although southern pine sawtimber markets were not globally integrated, local supply and demand shocks did transmit partially to immediate neighboring regions, and could also have weaker effects in more distant regions.impulse response, market integration, space-time model, spatial correlation, Demand and Price Analysis,

An investigation of the violin teaching method of Lin Yaoji from a personal perspective

As a Western musical instrument, the Violin has a history spanning more than three hundred years. Contemporary approaches to its performance and pedagogy have been developed and influenced by the Russian, the Franco-Belgian, and the German Violin Schools. It was not until the 1920s and \u2730s, that the violin entered the public realm of Chinese society. From the 1980s until today, several generations of violinists have emerged as Violin Educators in China. Among them, Lin Yaoji was the most famous. This study will research and examine Lin Yaoji’s violin teaching method. Specifically, this document will consist of five chapters discussing the following: (1) a general biographical introduction exploring Lin Yaoji as a pedagogue; (2) the Russian Violin School; (3) the philosophy of Lin’s teaching method; (4) Lin’s mnemonic rhymes, and (5) the researcher’s thoughts on Chinese violin education. The purpose of the current document is four-fold. Firstly, to offer an English translation of the content and pedagogical approaches of Lin as included in Yang’s work. Secondly, to offer my personal perspectives and interpretative insights concerning Lin’s and other well-known (non-Chinese) violin pedagogical approaches from the viewpoint of someone who grew up in China and studied violin there until graduate studies brought me to the United States. Thirdly, to provide important historical and cultural contextual information relevant to the growth of violin playing and the evolution of Lin’s approach. vii And finally, to celebrate and share Lin’s important pedagogical contributions to violin playing, his life achievements, and his legacy with the Western world

Applying machine learning to predict future adherence to physical activity programs.

BackgroundIdentifying individuals who are unlikely to adhere to a physical exercise regime has potential to improve physical activity interventions. The aim of this paper is to develop and test adherence prediction models using objectively measured physical activity data in the Mobile Phone-Based Physical Activity Education program (mPED) trial. To the best of our knowledge, this is the first to apply Machine Learning methods to predict exercise relapse using accelerometer-recorded physical activity data.MethodsWe use logistic regression and support vector machine methods to design two versions of a Discontinuation Prediction Score (DiPS), which uses objectively measured past data (e.g., steps and goal achievement) to provide a numerical quantity indicating the likelihood of exercise relapse in the upcoming week. The respective prediction accuracy of these two versions of DiPS are compared, and then numerical simulation is performed to explore the potential of using DiPS to selectively allocate financial incentives to participants to encourage them to increase physical activity.Resultswe had access to a physical activity trial data that were continuously collected every 60 sec every day for 9 months in 210 participants. By using the first 15 weeks of data as training and test on weeks 16-30, we show that both versions of DiPS have a test AUC of 0.9 with high sensitivity and specificity in predicting the probability of exercise adherence. Simulation results assuming different intervention regimes suggest the potential benefit of using DiPS as a score to allocate resources in physical activity intervention programs in reducing costs over other allocation schemes.ConclusionsDiPS is capable of making accurate and robust predictions for future weeks. The most predictive features are steps and physical activity intensity. Furthermore, the use of DiPS scores can be a promising approach to determine when or if to provide just-in-time messages and step goal adjustments to improve compliance. Further studies on the use of DiPS in the design of physical activity promotion programs are warranted.Trial registrationClinicalTrials.gov NCT01280812 Registered on January 21, 2011

The time value of options and writing strategies

This study examines the pattern of stock option time value decay and the implications of the time value decay pattern for option writing strategies. I also consider the returns to various options writing strategies. The central question is whether option writers can utilize a writing strategy that captures the time value of options as revenue to cover their risks and provides return on their investments. Using transaction data, I find that the time value of options that are near-the-money decays at a decreasing rate. The implications of this result are that a significant portion of the time value of near-the-money options decays in the early days of writing an option and the decay slows down as time to expiry approaches. This motivates us to compare over the same holding periods the writing returns of options with long times to expiry with the returns of options with short times to expiry. Overall, the results suggest that trading of options face significant transaction costs and it is mainly motivated by hedging or speculation as I did not find a systematic way to profit from option writing strategies. In addition, I examine the impact of market sentiment on the time value of options. The period of the study includes a sub-period when the general trend in the stock market was positive and another sub-period when the trend was negative. In particular, I study the price of puts relative to the price of calls during these two distinct market periods. I find that during bear markets both call and put options are more expensive than call and put options during bull markets. Yet, the ratio of put premiums to call premiums during rising markets is generally higher than the same ratio during bear markets. This observation suggests that speculators may be the dominant traders in options markets. Overall, I find that option writing strategies are not profitable. One of the reasons for this observation is transaction costs, which are significant in all the strategies that I examine. The bid-ask spread in the options market is large in comparison to the bid-ask spread in the underlying stock market