Publications by Zhi Ying Chen (Sec#1), Mengqin Cai (Sec#3), Fan Xu (Sec#4), Sin Ying Wong (Sec#4)
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Introduction New York City is one of the most famous places in the world. It draws millions of tourists every year which boosts our economy. NYC is therefore one of the hottest markets for Airbnb. Comparing to other nearby cities, New York City has the ease of commute by having a large subway coverage with varies bus lines and citibikes. self-gui...
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Section I Create an Example. Using one or more TidyVerse packages, and any dataset from fivethirtyeight.com or Kaggle, create a programming sample “vignette” that demonstrates how to use one or more of the capabilities of the selected TidyVerse package with your selected dataset. Data source: https://www.kaggle.com/spscientist/students-perfor...
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Data624_HW3
Question 2 The plastics data set consists of the monthly sales (in thousands) of product A for a plastics manufacturer for five years. a. Plot the time series of sales of product A. Can you identify seasonal fluctuations and/or a trend-cycle? autoplot(plastics)+ggtitle('Sales of plastic product') The plot shows a strong seasonality with upward ...
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library(fpp2) ## Warning: package 'fpp2' was built under R version 3.6.3 ## Registered S3 method overwritten by 'xts': ## method from ## as.zoo.xts zoo ## Registered S3 method overwritten by 'quantmod': ## method from ## as.zoo.data.frame zoo ## -- Attaching packages -----------------------------------------------------...
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Data624_HW1
library(fpp2) ## Warning: package 'fpp2' was built under R version 3.6.3 ## Registered S3 method overwritten by 'xts': ## method from ## as.zoo.xts zoo ## Registered S3 method overwritten by 'quantmod': ## method from ## as.zoo.data.frame zoo ## -- Attaching packages -----------------------------------------------------...
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Data624_HW6
ARIMA models 8.1 Figure 8.31 shows the ACFs for 36 random numbers, 360 random numbers and 1,000 random numbers. a. Explain the differences among these figures. Do they all indicate that the data are white noise? All three ACF plots are white noise because 95% of the spikes in the ACF lie within \(\pm2/ \sqrt{T}\) where T is the length of the ti...
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Data624_HW5
Question 7.1 Consider the pigs series — the number of pigs slaughtered in Victoria each month. a. Use the ses() function in R to find the optimal values of α and \(ℓ_0\), and generate forecasts for the next four months. fc<-ses(pigs, h=4) fc$model ## Simple exponential smoothing ## ## Call: ## ses(y = pigs, h = 4) ## ## Smoothi...
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Data624_HW4
Question 1 3.1 The UC Irvine Machine Learning Repository contains a data set related to glass identification. The data consist of 214 glass samples labeled as one of seven class categories. There are nine predictors, including the refractive index and percentages of eight elements: Na, Mg, Al, Si, K, Ca, Ba, and Fe. The data can be accessed via: ...
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Data624_project1
Part A – ATM Forecast In part A, I want you to forecast how much cash is taken out of 4 different ATM machines for May 2010. The data is given in a single file. The variable ‘Cash’ is provided in hundreds of dollars, other than that it is straight forward. I am being somewhat ambiguous on purpose to make this have a little more business fe...
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