% ! TeX program = lualatex \documentclass[a4paper,11pt]{article} % packages \usepackage{censor} \StopCensoring \usepackage{fontspec} \setmainfont{EB Garamond} % for tironian et fallback % % \directlua{luaotfload.add_fallback % % ("emojifallback", % % {"Noto Serif:mode=harf"} % % )} % % \setmainfont{EB Garamond}[RawFeature={fallback=emojifallback}] \setmonofont[Scale=MatchLowercase]{Deja Vu Sans Mono} \usepackage[a4paper,left=2cm,right=2cm,top=\dimexpr15mm+1.5\baselineskip,bottom=2cm]{geometry} \setlength{\parindent}{0pt} \usepackage{fancyhdr} % Headers and footers \fancyhead[R]{\normalfont \leftmark} \fancyhead[L]{} \pagestyle{fancy} \usepackage{microtype} % Slightly tweak font spacing for aesthetics \usepackage[english]{babel} % Language hyphenation and typographical rules \usepackage{xcolor} \definecolor{linkblue}{RGB}{0, 64, 128} \usepackage[final, colorlinks = false, urlcolor = linkblue]{hyperref} % \newcommand{\secref}[1]{\textbf{§~\nameref{#1}}} \newcommand{\secref}[1]{\textbf{§\ref{#1}~\nameref{#1}}} \usepackage{changepage} % adjust margins on the fly \usepackage{minted} \usemintedstyle{algol_nu} \usepackage{pgfplots} \pgfplotsset{width=\textwidth,compat=1.9} \usepackage{caption} \newenvironment{code}{\captionsetup{type=listing}}{} \captionsetup[listing]{skip=0pt} \setlength{\abovecaptionskip}{5pt} \setlength{\belowcaptionskip}{5pt} \usepackage[yyyymmdd]{datetime} \renewcommand{\dateseparator}{--} \usepackage{enumitem} \usepackage{titlesec} \author{Andrew Hayes} \begin{document} \begin{titlepage} \begin{center} \hrule \vspace*{0.6cm} \Huge \textsc{ct420} \vspace*{0.6cm} \hrule \LARGE \vspace{0.5cm} Real-Time Systems \vspace{0.5cm} \hrule \vfill \hrule \begin{minipage}{0.495\textwidth} \vspace{0.4em} \raggedright \normalsize \begin{tabular}{@{}l l} Name: & Andrew Hayes \\ Student ID: & 21321503 \\ E-mail: & \href{mailto://a.hayes18@universityofgalway.ie}{a.hayes18@universityofgalway.ie} \\ \end{tabular} \end{minipage} \begin{minipage}{0.495\textwidth} \raggedleft \vspace*{0.8cm} \Large \today \vspace*{0.6cm} \end{minipage} \medskip\hrule \end{center} \end{titlepage} \pagenumbering{roman} \newpage \tableofcontents \newpage \setcounter{page}{1} \pagenumbering{arabic} \section{Introduction} \subsection{Lecturer Contact Information} \begin{itemize} \item Name: Dr. Michael Schukat. \item E-mail: \href{mailto://michael.schukat@universityofgalway.ie}{michael.schukat@universityofgalway.ie}. \item Office: CSB-3002. \end{itemize} \begin{itemize} \item Name: Dr. Jawad Manzoor. \item E-mail: \href{jawad.manzoor@universityofgalway.ie}{jawad.manzoor@universityofgalway.ie}. \item Office: CSB-3012. \end{itemize} \subsection{Assessment} \begin{itemize} \item 2 hours of face-to-face \& virtual labs per week from Week 03. \item 30\% Continuous Assessment: \begin{itemize} \item 2 assignments, 10\% each. \item 2 in-class quizzes between Week 07 \& Week 12, worth 5\%. \end{itemize} \end{itemize} \subsection{Introduction to Real-Time Systems} A system is said to be \textbf{real-time} if the total correctness of an operation depends not only upon its logical correctness but also upon the time in which it is performed. Contrast functional requirements (logical correctness) versus non-functional requirements (time constraints). There are two main categorisation factors: \begin{itemize} \item \textbf{Criticality:} \begin{itemize} \item \textbf{Hard RTS:} deadlines (responsiveness) is critical. Failure to meet these have severe to catastrophic consequences (e.g., injury, damage, death). \item \textbf{Soft RTS:} deadlines are less critical, in many cases significant tolerance can be permitted. \end{itemize} \item \textbf{Speed} \begin{itemize} \item \textbf{Fast RTS:} responses in microseconds to hundreds of microseconds. \item \textbf{Slow RTS:} responses in the range of seconds to days. \end{itemize} \end{itemize} A \textbf{safety-critical system (SCS)} or life-critical system is a system whose failure or malfunction may result in death or serious injury to people, loss of equipment / property or severe damage, \& environmental harm. \section{The Essence of Time: From Measurement to Navigation \& Beyond} \textbf{Time} is the continued sequence of existence \& events that occurs in an apparently irreversible succession from past, through the present, into the future. Methods of temporal measurement, or chronometry, take two distinct forms: \begin{itemize} \item The \textbf{calendar}, a mathematical tool for organising intervals of term; \item The \textbf{clock}, a physical mechanism that counts the passage of time. \end{itemize} Global (maritime) exploration requires exact maritime navigation, i.e., longitude \& latitude calculation. \textbf{Latitude} (north-south) orientation is straightforward; \textbf{longitude} (east-west orientation) requires a robust (maritime) clock. \\\\ \textbf{Ground-based navigation systems} like LORAN (LOng RAnge Navigation) were developed in the 1940s and were in use until recently, and required fixed terrestrial longwave radio transmitters, and receivers on-board of ships \& planes. They are also referred to as hyperbolic navigation or multilateration. The principles of ground-based navigation systems is as follows: \begin{enumerate} \item A \textbf{master} with a known location broadcasts a radio pulse. \item Multiple \textbf{slave} stations with a known distance from the master send their own pulse, upon receiving the master pulse. \item A \textbf{receiver} receives master \& slave pulses and measures the delay between them. \item This allows the receiver to deduce the distance to each of the stations, providing a fix. \end{enumerate} \end{document}