|
|
|
@@ -1,43 +1,27 @@
|
|
|
|
\documentclass[journal]{IEEEtran}
|
|
|
|
\documentclass[journal]{IEEEtran}
|
|
|
|
|
|
|
|
|
|
|
|
\usepackage{amsmath,amsfonts}
|
|
|
|
\usepackage{amsmath,amsfonts}
|
|
|
|
|
|
|
|
\usepackage{siunitx}
|
|
|
|
|
|
|
|
\usepackage{mleftright}
|
|
|
|
\usepackage{float}
|
|
|
|
\usepackage{float}
|
|
|
|
\usepackage{titlesec}
|
|
|
|
\usepackage{titlesec}
|
|
|
|
\usepackage{algorithmic}
|
|
|
|
|
|
|
|
\usepackage{algorithm}
|
|
|
|
|
|
|
|
\usepackage{siunitx}
|
|
|
|
|
|
|
|
\usepackage[normalem]{ulem}
|
|
|
|
|
|
|
|
\usepackage{dsfont}
|
|
|
|
|
|
|
|
\usepackage{mleftright}
|
|
|
|
|
|
|
|
\usepackage{bbm}
|
|
|
|
|
|
|
|
\usepackage[
|
|
|
|
\usepackage[
|
|
|
|
backend=biber,
|
|
|
|
backend=biber,
|
|
|
|
style=ieee,
|
|
|
|
style=ieee,
|
|
|
|
sorting=nty,
|
|
|
|
sorting=nty,
|
|
|
|
]{biblatex}
|
|
|
|
]{biblatex}
|
|
|
|
|
|
|
|
|
|
|
|
\usepackage{tikz}
|
|
|
|
|
|
|
|
\usetikzlibrary{spy, arrows.meta,arrows}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
\usepackage{pgfplots}
|
|
|
|
\usepackage{pgfplots}
|
|
|
|
\pgfplotsset{compat=newest}
|
|
|
|
\pgfplotsset{compat=newest}
|
|
|
|
\usepgfplotslibrary{statistics}
|
|
|
|
\usepgfplotslibrary{statistics}
|
|
|
|
|
|
|
|
|
|
|
|
\usepackage{pgfplotstable}
|
|
|
|
|
|
|
|
\usepackage{filecontents}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
\hyphenation{op-tical net-works semi-conduc-tor IEEE-Xplore}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
%
|
|
|
|
%
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
% Template modifications
|
|
|
|
% Template modifications
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
%
|
|
|
|
%
|
|
|
|
|
|
|
|
|
|
|
|
% TODO: "The right strategy" pun
|
|
|
|
\titlespacing*{\section}{0mm}{3mm}{1mm}
|
|
|
|
|
|
|
|
|
|
|
|
\titlespacing*{\section}
|
|
|
|
|
|
|
|
{0mm}{3mm}{1mm}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
\makeatletter
|
|
|
|
\makeatletter
|
|
|
|
\def\@maketitle{%
|
|
|
|
\def\@maketitle{%
|
|
|
|
@@ -46,11 +30,11 @@
|
|
|
|
\vspace*{-4mm}
|
|
|
|
\vspace*{-4mm}
|
|
|
|
\begin{center}%
|
|
|
|
\begin{center}%
|
|
|
|
{\Huge \linespread{0.9}\selectfont \@title \par}%
|
|
|
|
{\Huge \linespread{0.9}\selectfont \@title \par}%
|
|
|
|
{\large
|
|
|
|
{\large \lineskip .5em%
|
|
|
|
\lineskip .5em%
|
|
|
|
|
|
|
|
\begin{tabular}[t]{c}%
|
|
|
|
\begin{tabular}[t]{c}%
|
|
|
|
\@author
|
|
|
|
\@author
|
|
|
|
\end{tabular}\par}%
|
|
|
|
\end{tabular}
|
|
|
|
|
|
|
|
\par}%
|
|
|
|
\end{center}%
|
|
|
|
\end{center}%
|
|
|
|
\vspace*{-8mm}
|
|
|
|
\vspace*{-8mm}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
@@ -111,12 +95,12 @@
|
|
|
|
Performance}
|
|
|
|
Performance}
|
|
|
|
|
|
|
|
|
|
|
|
\author{Some concerned fellow students%
|
|
|
|
\author{Some concerned fellow students%
|
|
|
|
\thanks{The authors would like to thank their hard-working peers as well as
|
|
|
|
\thanks{The authors would like to thank their hard-working peers as
|
|
|
|
the staff of the KIT library for their unknowing - but vital -
|
|
|
|
well as the staff of the KIT library for their unknowing - but vital
|
|
|
|
participation.}}
|
|
|
|
- participation.}}
|
|
|
|
|
|
|
|
|
|
|
|
\markboth{Journal of the Association of KIT Bibliophiles}{The
|
|
|
|
\markboth{Journal of the Association of KIT Bibliophiles}{The Effect
|
|
|
|
Effect of the Choice of Hydration Strategy on Average Academic Performance}
|
|
|
|
of the Choice of Hydration Strategy on Average Academic Performance}
|
|
|
|
|
|
|
|
|
|
|
|
\maketitle
|
|
|
|
\maketitle
|
|
|
|
|
|
|
|
|
|
|
|
@@ -126,14 +110,13 @@ Effect of the Choice of Hydration Strategy on Average Academic Performance}
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
%
|
|
|
|
%
|
|
|
|
|
|
|
|
|
|
|
|
% \vspace*{-10mm}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
\begin{abstract}
|
|
|
|
\begin{abstract}
|
|
|
|
We evaluate the relationship between hydration strategy and
|
|
|
|
We evaluate the relationship between hydration strategy and
|
|
|
|
academic performance and project that by using the right button of
|
|
|
|
academic performance and project that by using the right button
|
|
|
|
the water dispenser to fill up their water bottles, students can potentially
|
|
|
|
of the water dispenser to fill up their water bottles, students
|
|
|
|
gain up to \SI{4.14}{\second} of study time per refill, which is amounts to
|
|
|
|
can potentially gain up to \SI{4.14}{\second} of study time per
|
|
|
|
raising their grades by up to 0.00103 points.
|
|
|
|
refill, which amounts to raising their grades by up to
|
|
|
|
|
|
|
|
$0.0003$ points.
|
|
|
|
\end{abstract}
|
|
|
|
\end{abstract}
|
|
|
|
|
|
|
|
|
|
|
|
\begin{IEEEkeywords}
|
|
|
|
\begin{IEEEkeywords}
|
|
|
|
@@ -151,41 +134,37 @@ Effect of the Choice of Hydration Strategy on Average Academic Performance}
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
\section{Introduction}
|
|
|
|
\section{Introduction}
|
|
|
|
|
|
|
|
|
|
|
|
\IEEEPARstart{T}{he} concepts of hydration and study have always been tightly
|
|
|
|
% TODO: "The right strategy" pun?
|
|
|
|
interwoven. As an example, an investigation was once conducted by Bell Labs
|
|
|
|
|
|
|
|
into the productivity of their employees that found that ``workers with the
|
|
|
|
\IEEEPARstart{T}{he} concepts of hydration and study have always been
|
|
|
|
most patents often shared lunch or breakfast with a Bell Labs electrical
|
|
|
|
tightly interwoven. As an example, an investigation was once
|
|
|
|
engineer named Harry Nyquist'' \cite{gertner_idea_2012}, and we presume that
|
|
|
|
conducted by Bell Labs into the productivity of their employees, that
|
|
|
|
they also paired their food with something to drink. We can see that
|
|
|
|
found that ``workers with the most patents often shared lunch or
|
|
|
|
intellectual achievement and fluid consumption are related even for the most
|
|
|
|
breakfast with a Bell Labs electrical engineer named Harry Nyquist''
|
|
|
|
|
|
|
|
\cite{gertner_idea_2012}, and we presume that they also paired their
|
|
|
|
|
|
|
|
food with something to drink. We can see that intellectual
|
|
|
|
|
|
|
|
achievement and fluid consumption are related even for the most
|
|
|
|
prestigious research institutions.
|
|
|
|
prestigious research institutions.
|
|
|
|
|
|
|
|
|
|
|
|
In this work, we quantify this relationship in the context of studying at the
|
|
|
|
In this work, we quantify this relationship in the context of
|
|
|
|
KIT library and subsequently develop a novel and broadly applicable strategy
|
|
|
|
studying at the KIT library and subsequently develop a novel and
|
|
|
|
to leverage it to improve the academic performance of KIT students.
|
|
|
|
broadly applicable strategy to leverage it to improve the academic
|
|
|
|
|
|
|
|
performance of KIT students.
|
|
|
|
|
|
|
|
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
\section{Experimental Setup}
|
|
|
|
\section{Experimental Setup}
|
|
|
|
|
|
|
|
|
|
|
|
Over a period of one week, we monitored the usage of the water dispenser
|
|
|
|
Over a period of one week, we monitored the use of the water
|
|
|
|
on the ground floor of the KIT library at random times during the day.
|
|
|
|
dispenser on the ground floor of the KIT library at random times
|
|
|
|
The experiment comprised two parts, a system measurement to determine the
|
|
|
|
during the day. The experiment comprised two parts: a system
|
|
|
|
flowrate of the water dispenser, and a behavioural measurement, i.e.,
|
|
|
|
measurement to determine the flowrate of the water dispenser, and a
|
|
|
|
a recording
|
|
|
|
behavioural measurement, i.e., a record of participants' chosen
|
|
|
|
of the choice of hydration strategy of the participants: $S_\text{L}$ denotes
|
|
|
|
hydration strategies: $S_\text{L}$ denotes pressing the left
|
|
|
|
pressing the left button of the water dispenser, $S_\text{R}$ the right one,
|
|
|
|
button of the water dispenser, $S_\text{R}$ the right one, and
|
|
|
|
and $S_\text{B}$ pressing both buttons.
|
|
|
|
$S_\text{B}$ pressing both buttons.
|
|
|
|
|
|
|
|
|
|
|
|
For the system measurement $10$ datapoints were recorded for each strategy,
|
|
|
|
For the system measurement $10$ datapoints were recorded for each
|
|
|
|
for the behavioural measurement $113$ in total.
|
|
|
|
strategy, for the behavioural measurement $113$ in total.
|
|
|
|
|
|
|
|
|
|
|
|
% As is always the case with measurements, care must be taken not to alter
|
|
|
|
|
|
|
|
% quantities by measuring them. To this end, we made sure only to take system
|
|
|
|
|
|
|
|
% measurements in the absence of participants and to only record data on the
|
|
|
|
|
|
|
|
% behaviour of participants discreetly.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
% TODO: Describe the actual measurement setup? (e.g., filling up a 0.7l bottle
|
|
|
|
|
|
|
|
% and timing with a standard smartphone timer)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
\section{Experimental Results}
|
|
|
|
\section{Experimental Results}
|
|
|
|
@@ -228,16 +207,13 @@ for the behavioural measurement $113$ in total.
|
|
|
|
\end{figure}
|
|
|
|
\end{figure}
|
|
|
|
|
|
|
|
|
|
|
|
Fig. \ref{fig:System} shows the results of the system measurement.
|
|
|
|
Fig. \ref{fig:System} shows the results of the system measurement.
|
|
|
|
We observe that $S_\text{L}$ is the slowest strategy, while $S_\text{R}$
|
|
|
|
To investigate the difference in flowrate between strategies, we used
|
|
|
|
and $S_\text{B}$ are similar. Due to the small sample size and the
|
|
|
|
a Mann Whitney U test, because of its nonparametric nature.
|
|
|
|
unknown distribution, the test we chose to verify this observation is a Mann
|
|
|
|
We found that $S _\text{L}$ was slower than
|
|
|
|
Whitney U test. We found that $S _\text{L}$ is faster than $S_\text{R}$ with a
|
|
|
|
$S_\text{R}$ with a significance of $p < 0.01$, while no
|
|
|
|
significance of $p < 0.0001$, while no significant statement could be made
|
|
|
|
statistically significant difference was found between $S_\text{R}$ and
|
|
|
|
about $S_\text{R}$ and $S_\text{B}$.
|
|
|
|
$S_\text{B}$. The results of the behavioural measurement are shown in
|
|
|
|
Fig. \ref{fig:Behavior} shows the results of the behavioural measurement.
|
|
|
|
Fig. \ref{fig:Behavior}.
|
|
|
|
% During this part of the experiment, we also measured the time each participant
|
|
|
|
|
|
|
|
% needed to fill up their bottle. Using the measured flowrates we calculated
|
|
|
|
|
|
|
|
% the mean refill volume to be $\SI{673.92}{\milli\liter}$.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
\begin{figure}[H]
|
|
|
|
\begin{figure}[H]
|
|
|
|
\centering
|
|
|
|
\centering
|
|
|
|
@@ -272,108 +248,51 @@ Fig. \ref{fig:Behavior} shows the results of the behavioural measurement.
|
|
|
|
\end{figure}
|
|
|
|
\end{figure}
|
|
|
|
|
|
|
|
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
\section{Modelling}
|
|
|
|
\section{Modelling the grade improvement}
|
|
|
|
|
|
|
|
|
|
|
|
We can consider the water dispenser and students as comprising a queueing
|
|
|
|
We can consider the water dispenser and students as comprising a
|
|
|
|
system, specifically an M/G/1 queue \cite{stewart_probability_2009}.
|
|
|
|
queueing system, specifically an M/G/1 queue
|
|
|
|
The expected response time, i.e., the time spent waiting as well as
|
|
|
|
\cite{stewart_probability_2009}. The expected response time, i.e.,
|
|
|
|
the time dispensing water, is \cite[Section 14.3]{stewart_probability_2009}%
|
|
|
|
the time spent waiting as well as the time dispensing water, is
|
|
|
|
|
|
|
|
\cite[Section 14.3]{stewart_probability_2009}%
|
|
|
|
|
|
|
|
%
|
|
|
|
\begin{align*}
|
|
|
|
\begin{align*}
|
|
|
|
W = E\mleft\{ S \mright\} + \frac{\lambda E\mleft\{ S^2
|
|
|
|
W = E\mleft\{ S \mright\} + \frac{\lambda \cdot E\mleft\{ S^2
|
|
|
|
\mright\}}{2\mleft( 1-\rho \mright)}
|
|
|
|
\mright\}}{2\mleft( 1-\rho \mright)}
|
|
|
|
,%
|
|
|
|
,%
|
|
|
|
\end{align*}%
|
|
|
|
\end{align*}%
|
|
|
|
where $S$ denotes the service time (i.e., the time spent refilling a bottle),
|
|
|
|
%
|
|
|
|
$\lambda$ the mean arrival rate, and $\rho = \lambda \cdot E\mleft\{
|
|
|
|
where $S$ denotes the service time (i.e., the time spent refilling a
|
|
|
|
S \mright\}$ the system utilization. Using our
|
|
|
|
bottle), $\lambda$ the mean arrival rate, and $\rho = \lambda \cdot
|
|
|
|
experimental data we can approximate all parameters and obtain
|
|
|
|
E\mleft\{ S \mright\}$ the system utilisation. Using our experimental
|
|
|
|
$W \approx \SI{23.3}{\second}$. The difference to always using
|
|
|
|
data we can approximate all parameters and obtain $W \approx
|
|
|
|
the fastest strategy amounts to $\SI{4.14}{\second}$.
|
|
|
|
\SI{23.3}{\second}$. The difference to always using the fastest
|
|
|
|
% We examine the effects of the choice of hydration strategy. To
|
|
|
|
strategy amounts to $\SI{4.14}{\second}$.
|
|
|
|
% this end, we start by estimating the potential time savings possible by always
|
|
|
|
|
|
|
|
% choosing the fastest strategy:%
|
|
|
|
|
|
|
|
% %
|
|
|
|
|
|
|
|
% % We can model the time needed for one person to refill their
|
|
|
|
|
|
|
|
% bottle as a random
|
|
|
|
|
|
|
|
% % variable (RV) $T_1 = V/R$ and the time saved by choosing the
|
|
|
|
|
|
|
|
% fastest strategy
|
|
|
|
|
|
|
|
% % as $\Delta T_1 = T_1 - V/\max r$, where $V$ and $R$ are RVs representing the
|
|
|
|
|
|
|
|
% % bottle volume and flowrate. The potential time saving for the
|
|
|
|
|
|
|
|
% last person in a
|
|
|
|
|
|
|
|
% % queue of $N$ people is thus $\Delta T_N = N\cdot\Delta T_1$. We
|
|
|
|
|
|
|
|
% can then model
|
|
|
|
|
|
|
|
% % the total time savings as $\Delta T_\text{tot} = \sum_{n=1}^{N} \Delta T_n$,
|
|
|
|
|
|
|
|
% % where N is an RV describing the queue length. Assuming the
|
|
|
|
|
|
|
|
% independence of all
|
|
|
|
|
|
|
|
% % RVs we can compute the mean total time savings as
|
|
|
|
|
|
|
|
% %
|
|
|
|
|
|
|
|
% \begin{gather*}
|
|
|
|
|
|
|
|
% T_1 = V/R, \hspace{3mm} \Delta T_1 = T_1 - V/\max R,
|
|
|
|
|
|
|
|
% \hspace{3mm} \Delta T_n = n \cdot \Delta T_1 \\
|
|
|
|
|
|
|
|
% \Delta T_\text{tot} = \sum_{n=1}^{N} \Delta T_\text{n} =
|
|
|
|
|
|
|
|
% \sum_{n=1}^{N} n \cdot \Delta T_1 = \Delta T_1 \frac{N\mleft( N+1
|
|
|
|
|
|
|
|
% \mright)}{2} \\
|
|
|
|
|
|
|
|
% \Delta t := E\mleft\{ \Delta T_\text{tot} \mright\} = E\mleft\{
|
|
|
|
|
|
|
|
% \Delta T_1 \mright\} \cdot \mleft[ E\mleft\{ N^2 \mright\} +
|
|
|
|
|
|
|
|
% E\mleft\{ N \mright\} \mright]/2
|
|
|
|
|
|
|
|
% ,%
|
|
|
|
|
|
|
|
% \end{gather*}
|
|
|
|
|
|
|
|
% %
|
|
|
|
|
|
|
|
% where $V$ and $R$ are random variables (RVs) representing the volume of a
|
|
|
|
|
|
|
|
% bottle and the flowrate, $\Delta T_n$ describes the time the last of $n$
|
|
|
|
|
|
|
|
% people saves, $\Delta T_\text{tot}$ the total time savings and $N$ the length
|
|
|
|
|
|
|
|
% of the queue. It is plausible to assume independence of $R,V$ and $N$.
|
|
|
|
|
|
|
|
% Using our experimental measurements we estimate $\todo{\Delta t =
|
|
|
|
|
|
|
|
% \SI{20}{\second}}$
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Strangely, it is the consensus of current research that there is only
|
|
|
|
Strangely, it is the consensus of current research that there is only
|
|
|
|
a weak relationship between academic performance and hours studied
|
|
|
|
a weak relationship between academic performance and hours studied
|
|
|
|
\cite{plant_why_2005}.
|
|
|
|
\cite{plant_why_2005}. Observing Figure 1 in
|
|
|
|
The largest investigation into the matter found a correlation of
|
|
|
|
\cite[p. 950]{schuman_effort_1985} and performing a linear regression,
|
|
|
|
$\rho = 0.18$ \cite{schuman_effort_1985} between GPA and average time
|
|
|
|
we quantified the grade gain per additional hour studied as
|
|
|
|
spend studying per day. Using a rather high estimate of 5 refills per
|
|
|
|
$\SI{0.054}{points/hour}$. Using an estimate of 5 refills per day, we
|
|
|
|
day, we predict a possible grade gain of up to $0.00103$ points.
|
|
|
|
thus predict a possible gain of up to $0.0003$ points.
|
|
|
|
|
|
|
|
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
\section{Discussion and Conclusion}
|
|
|
|
\section{Discussion and Conclusion}
|
|
|
|
|
|
|
|
|
|
|
|
Further research is needed, particularly on the modelling of the
|
|
|
|
Further research is needed, particularly on the modelling of the
|
|
|
|
arrival process and the relationship between the response time gain
|
|
|
|
arrival process and the relationship between the response time and
|
|
|
|
the grade gain. Nevertheless, we believe this work serves as a solid
|
|
|
|
the grade gain. Nevertheless, we believe this work serves as a solid
|
|
|
|
first step on the path towards achieving optimal study behaviour.
|
|
|
|
first step on the path towards achieving optimal study behaviour.
|
|
|
|
|
|
|
|
|
|
|
|
% Many attempts have been made in the literature to relate
|
|
|
|
|
|
|
|
% the time spent studying to academic achievement - see, e.g.
|
|
|
|
|
|
|
|
% \cite{schuman_effort_1985, zulauf_use_1999, michaels_academic_1989,
|
|
|
|
|
|
|
|
% dickinson_effect_1990}.
|
|
|
|
|
|
|
|
% The overwhelming consensus is that there is a significant relationship,
|
|
|
|
|
|
|
|
% though it is a weak one.
|
|
|
|
|
|
|
|
%
|
|
|
|
|
|
|
|
%Many of the studies were only performed over
|
|
|
|
|
|
|
|
% a period of one week or even day, so we believe care should be taken when
|
|
|
|
|
|
|
|
% generlizing these results. Nevertheless, the overwhelming consensus in the
|
|
|
|
|
|
|
|
% literature is that a significant relationship exists, though it is a weak one.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
|
|
|
|
% \section{Conclusion}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
In this study, we investigated how the choice of hydration strategy
|
|
|
|
In this study, we investigated how the choice of hydration strategy
|
|
|
|
affects average academic performance. We found that always
|
|
|
|
affects average academic performance. We found that always choosing
|
|
|
|
choosing to press the right button leads to an average time gain of
|
|
|
|
to press the right button leads to an average time gain of
|
|
|
|
\SI{4.14}{\second} per refill, which translates into a grade
|
|
|
|
\SI{4.14}{\second} per refill, which translates into a grade
|
|
|
|
improvement of up to $0.00103$ levels. We thus propose a novel and
|
|
|
|
improvement of up to $0.0003$ points. We thus propose a novel and
|
|
|
|
broadly applicable strategy to boost the average academic performance
|
|
|
|
broadly applicable strategy to boost the average academic performance
|
|
|
|
of KIT students: always using the right button.
|
|
|
|
of KIT students: always using the right button.
|
|
|
|
|
|
|
|
|
|
|
|
% Further research is needed to develop a better model of how the choice of
|
|
|
|
|
|
|
|
% hydration strategy is related to academic performance. We
|
|
|
|
|
|
|
|
% suspect that there is a compounding effect that leads to $S_\text{L}$ being an
|
|
|
|
|
|
|
|
% even worse choice of hydration strategy: When the queue is long, students are
|
|
|
|
|
|
|
|
% less likely to refill their empty water bottles, leading to reduced mental
|
|
|
|
|
|
|
|
% ability. Nevertheless, we believe that with this work we have laid a solid
|
|
|
|
|
|
|
|
% foundation and hope that our results will find widespread acceptance among the
|
|
|
|
|
|
|
|
% local student population.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
%
|
|
|
|
%
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
% Bibliography
|
|
|
|
% Bibliography
|
|
|
|
@@ -382,75 +301,5 @@ of KIT students: always using the right button.
|
|
|
|
|
|
|
|
|
|
|
|
\printbibliography
|
|
|
|
\printbibliography
|
|
|
|
|
|
|
|
|
|
|
|
% \appendix
|
|
|
|
|
|
|
|
%
|
|
|
|
|
|
|
|
% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|
|
|
|
|
|
|
|
% \section{Derivation of Service Time}
|
|
|
|
|
|
|
|
% \label{sec:Derivation of Service Time}
|
|
|
|
|
|
|
|
%
|
|
|
|
|
|
|
|
%
|
|
|
|
|
|
|
|
% We want to compute the response time of our queueing system, i.e.,
|
|
|
|
|
|
|
|
% \cite[Section 14.3]{stewart_probability_2009}
|
|
|
|
|
|
|
|
% \begin{align*}
|
|
|
|
|
|
|
|
% W = E\mleft\{ S \mright\} + \frac{\lambda E\mleft\{ S^2
|
|
|
|
|
|
|
|
% \mright\}}{2\mleft( 1-\rho \mright)}
|
|
|
|
|
|
|
|
% .%
|
|
|
|
|
|
|
|
% \end{align*}%
|
|
|
|
|
|
|
|
% We start by modelling the service time and subsequently calculate $\lambda$
|
|
|
|
|
|
|
|
% and $\rho$.
|
|
|
|
|
|
|
|
%
|
|
|
|
|
|
|
|
% Let $S, V$ and $R$ be random variables denoting the service time,
|
|
|
|
|
|
|
|
% refill volume
|
|
|
|
|
|
|
|
% and refill rate, respectively. Assuming that $V$ and $R$ are independent, we
|
|
|
|
|
|
|
|
% have
|
|
|
|
|
|
|
|
% \begin{gather*}
|
|
|
|
|
|
|
|
% S = \frac{V}{R} \hspace{5mm} \text{and} \hspace{5mm}
|
|
|
|
|
|
|
|
% P_R(r) = \left\{\begin{array}{rl}
|
|
|
|
|
|
|
|
% P(S_\text{L}), & r = r_{S_\text{L}} \\
|
|
|
|
|
|
|
|
% 1-P(S_\text{L}), & r = r_{S_\text{R}}
|
|
|
|
|
|
|
|
% \end{array}\right.
|
|
|
|
|
|
|
|
% \end{gather*}%
|
|
|
|
|
|
|
|
% \begin{align*}
|
|
|
|
|
|
|
|
% E\mleft\{ S^2 \mright\} &= E\mleft\{ V^2 \mright\}E\mleft\{ 1 /
|
|
|
|
|
|
|
|
% R^2 \mright\} \\
|
|
|
|
|
|
|
|
% & = E\mleft\{ V^2 \mright\} \mleft(
|
|
|
|
|
|
|
|
% P(S_\text{L})\frac{1}{r^2_{S_\text{L}}} + \mleft( 1 - P(S_\text{L})
|
|
|
|
|
|
|
|
% \mright)\frac{1}{r^2_{S_\text{R}}} \mright)
|
|
|
|
|
|
|
|
% .%
|
|
|
|
|
|
|
|
% \end{align*}
|
|
|
|
|
|
|
|
% We now use our experimental data (having calculated $v_n, n\in [1:N]$ from the
|
|
|
|
|
|
|
|
% measured fill times and flow rates) to compute
|
|
|
|
|
|
|
|
% \begin{align*}
|
|
|
|
|
|
|
|
% \left.
|
|
|
|
|
|
|
|
% \begin{array}{r}
|
|
|
|
|
|
|
|
% E\mleft\{ V^2 \mright\} \approx \frac{1}{N+1}
|
|
|
|
|
|
|
|
% \sum_{n=1}^{N} v_n^2 = \todo{15}\\
|
|
|
|
|
|
|
|
% P(S_\text{L}) \approx \frac{\text{\# times $S_\text{L}$ was
|
|
|
|
|
|
|
|
% chosen}}{N} = \todo{123} \\
|
|
|
|
|
|
|
|
% r^2_{S_\text{L}} \approx \todo{125} \\
|
|
|
|
|
|
|
|
% r^2_{S_\text{R}} \approx \todo{250}
|
|
|
|
|
|
|
|
% \end{array}
|
|
|
|
|
|
|
|
% \right\} \Rightarrow
|
|
|
|
|
|
|
|
% \left\{
|
|
|
|
|
|
|
|
% \begin{array}{l}
|
|
|
|
|
|
|
|
% E\mleft\{ S \mright\} \approx \todo{678} \\
|
|
|
|
|
|
|
|
% E\mleft\{ S^2 \mright\} \approx \todo{123}
|
|
|
|
|
|
|
|
% \end{array}
|
|
|
|
|
|
|
|
% \right.
|
|
|
|
|
|
|
|
% .%
|
|
|
|
|
|
|
|
% \end{align*}
|
|
|
|
|
|
|
|
%
|
|
|
|
|
|
|
|
% $\lambda$ is the mean arrival time.
|
|
|
|
|
|
|
|
%
|
|
|
|
|
|
|
|
% \todo{
|
|
|
|
|
|
|
|
% \textbf{TODOs:}
|
|
|
|
|
|
|
|
% \begin{itemize}
|
|
|
|
|
|
|
|
% \item Complete text describing / obtaining $\rho$ and $\lambda$
|
|
|
|
|
|
|
|
% \item Move model derivation to method section
|
|
|
|
|
|
|
|
% \item Move calculations with model to results section
|
|
|
|
|
|
|
|
% \item Add grade gain derivation
|
|
|
|
|
|
|
|
% \item Idea: Make the whole thing 2 pages and print on A3
|
|
|
|
|
|
|
|
% \end{itemize}
|
|
|
|
|
|
|
|
% }
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
\end{document}
|
|
|
|
\end{document}
|
|
|
|
|
|
|
|
|
|
|
|
|