Publications by John K. Hancock
CUNY Data 612 Research Discussion 2
Research Question For this discussion item, please watch the following talk and summarize what you found to be the most important or interesting points. The first half will cover some of the mathematical techniques covered in this unit’s reading and the second half some of the data management challenges in an industrial-scale recommendation sys...
4961 sym
CUNY DATA 612 - Project 2
1 Project Scope The goal of this assignment is for you to try out different ways of implementing and configuring a recommender, and to evaluate your different approaches. 2 Introduction This project builds two recommender systems: User Based Collaborative Filtering (UBCF) and Item Based Collaborative Filtering (ICBF) using data from the MovieLen...
24056 sym R (13555 sym/86 pcs) 17 img 4 tbl
CUNY DATA612 Project three
1 Project Scope Implement a matrix factorization method—such as singular value decomposition (SVD) or Alternating Least Squares (ALS)—in the context of a recommender system. 2 Introduction I begin this project with a discussion of Singular Value Decomposition and how it can be used in recommender systems which is then followed by a Toy examp...
26094 sym R (23174 sym/88 pcs) 4 img 1 tbl
CUNY Data612 Research Discussion 3
Research Question As more systems and sectors are driven by predictive analytics, there is increasing awareness of the possibility and pitfalls of algorithmic discrimination. In what ways do you think Recommender Systems reinforce human bias? Reflecting on the techniques we have covered, do you think recommender systems reinforce or help to preve...
4629 sym
CUNY DATA612 Project 3
1 Project Scope The goal of this assignment is give you practice working with accuracy and other recommender system metrics. Choose a different dataset to work with from your previous projects. Deliverables 1. As in your previous assignments, compare the accuracy of at least two recommender system algorithms against your offline data. 2. Implemen...
22871 sym R (33310 sym/101 pcs) 12 img
DATA 624 Spring 2021 Homework three
Question No. 6.9.2: The plastics data set consists of the monthly sales (in thousands) of product A for a plastics manufacturer for five years. Background Information ANSWER: The plastics dataset is a monthly time series. help("plastics") ## starting httpd help server ... done Sales of plastic product Description Monthly sales of product A for ...
10256 sym R (3171 sym/29 pcs) 11 img
CUNY Data 624 Homework 1 - Spring 2021
2.10 Question No. 1 Use the help function to explore what the series gold, woolyrnq and gas represent. ANSWER: For question one, the author is asking to use exploratory data techniques to get insight and visualize each time series. Gold We can confirm that the Gold dataset is a Time Series dataset by applying the class method. The result “ts...
25306 sym R (5505 sym/114 pcs) 33 img
CUNY Data 624 Draft RMD file for Group Presentation
GE <- read.csv("https://raw.githubusercontent.com/JohnKHancock/raw.github/master/CUNY_DATA_624/stock_data_GE.csv", header = TRUE, stringsAsFactors = FALSE) GE$date <- as.Date(GE$date, "%m/%d/%Y") GE$month = lubridate::month(GE$date) GE$year = lubridate::year(GE$date) GE.monthly <- GE %>% group_by(year, month) %>% ...
1184 sym R (2199 sym/15 pcs) 5 img
Holt_Winters_Expo_Smoothing
Holt-Winters’ Seasonal Method An extension of Holt’s method to capture seasonality. Comprised of forecast Equation and three smoothing equations: - One for the level - One for the trend - One for the seasonal component with corresponding smoothing parameters: \[ \alpha, \beta*, and \gamma \] There are two variations to this method that di...
8297 sym R (5206 sym/16 pcs) 6 img
CUNY Data 624 Homework 2
Question No. 3.1: For the following series, find an appropriate Box-Cox transformation in order to stabilise the variance. Analysis The author tasks us with transforming time series by applying the Box Cox transformation. BoX-Cox transformations are used to normalize dependent variables. It is done so that the errors of the data are normally dis...
19851 sym R (4369 sym/72 pcs) 26 img