\chapter{Introduction}
\section{Purpose}

An arcology combines urban planning and architecture with the mechanics of ecology,
essentially forming an environmentally-friendly (or at least sustainable) human living system.
These systems are well-suited to systems engineering analysis. 

From a historical perspective, arcologies are mostly the subject of science fiction.
In a typical scenario, the principles of arcology development are applied
to the design of self-contained habitats,
where the major challenge lies in finding ways for large groups
of people to tolerate living in dense proximity to one another.
In addition to maximizing quality of life for its residents,
the arcology needs to limit consumption of land, energy, time and human resources.
Achieving an appropriate balance in these (often competing) criteria
requires that designers look beyond
maximization of personal productivity and/or economic performance,
and explicitly consider relationships among all factors
affecting system functionality, performance, and resource consumption.
The common characteristics of ``good design solutions'' include:
(1) Replacement of present-day urban sprawls with large
three-dimensional urban forms (i.e., hyperstructures),
(2) Extensive use of multi-functional spaces, and
(3) Use of sophisticated transportation networks and systems to
transfer of people and resources (e.g., power and water) between spaces.

Now that the World's population is 6.5 billion
and growing annually at 1.14\% (estimates as of July 2006) the
influence of these spearheading ideas is definitely spreading.
Indeed, it may only be a matter of decades until modeling techniques tailored
toward the needs of arcologies and/or other forms of
well-integrated compact cities become common place.
Early indicators of this trend can be found in experimental
prototypes for futuristic living (e.g., BioSphere 2 \cite{biosphere2})
and long-term plans for sustainable communities and
major cities in East Asia \cite{takenaka,millenniumtower,frick,tsui,ecodesigns}.

\vspace{0.1 truein}\noindent
{\bf Project Objectives.}
The thesis defines and describes a simulation framework
for the execution of demand-responsive multimodal mass transit schemes,
such as those found in complex urban environments.
Attention is focussed on resident and employer needs (i.e.,
shuttling passengers from their source stations to their destination stations.)
By measuring the performance of various solutions,
we aim to determine effective strategies for efficiently transferring
people to their destinations in relation to input parameters such
as demand, transit network topology, and the relative
size(s) of the vehicles used in the fleet.
This framework also allows us to experiment with
different urban planning layouts and to investigate relationships
between services provided by data networks and transportation networks.
For example, if a city decides to spend money upgrading their data
infrastructure so more people might be able to telecommute to work,
then this may have a noticeable
impact on the load on their mass transit system.

While the simulation and optimization models are certainly
generic enough to apply to most ordinary forms of mass transit,
for two reasons this project chooses to
frame models in the in the context of an arcology.
First of all, the word ``arcology'' still remains rather unique
in the global namespace of the engineering field,
and connotes a flair for futurism.
More importantly, the design focus of arcologies as an
autonomous structure encourages us to analyze it in terms of control volumes,
defining the flows of input and output products
in ways much more conducive to identifying resource consumption
and environmental impact. While the concept of analysis via the definition
of control volumes may come naturally only to engineers trained in
thermodynamics, it is refreshing to see efforts emerging to track
our ``carbon footprint'' as part of a global carbon dioxide emissions
budget. Hopefully this step will preclude more complete tracking and
accounting (and eventually optimization) of human environmental resource
use and waste for reclamation.

\section{Inspiration for Arcology Modeling}

It all goes back to the meaning of life, doesn't it?
Humans spend inordinate amounts of time
looking for love or money or happiness,
always trying to get the most out of life - in essence
optimizing our existence in some fashion.
The optimization part is where simulation can be a useful tool,
as we often disagree on what infrastructure improvements
we could make in order to make us happier or richer or work not so
far from our loved ones. For all the aspirations we've had over the
decades of reaching for the stars and developing permanent space colonies,
I'm surprised by the relatively little success we've had in improving
the efficiency of our lifestyles in our dwellings right here on Earth.
As summarized in Table \ref{tab:municipal-home-interfaces},
the ideal American domicile still consists of the single family home,
an almost completely isolated pocket of land connected to the rest
of the community only by a few wires, pipes, and a stretch of pavement.
What goes across these interfaces? And how might they be improved
and rearranged by municipal facilities to make the city as a whole
more sustainable, flexible, and efficient?

As a first step toward understanding these complexities,
let us note that living systems seem to have a
natural tendency to miniaturize complexity,
both in space and time.
A mathematician might draw the analogy that we live
on the interesting boundary region of a fractal, often surrounded
by vast regions of fairly uniform space. While the sun and stars and
universe are beautiful and magnificent only when observed on a grand
scale, I'd surmise that they are not as interesting when studied on
the same scale as, say, the inner workings of a paramecium. That's
one of the main reasons as astronomers, we might search the heavens
for deeper understanding of celestial mechanics, but hope to discover
other forms of alien life. For living systems of sufficient complexity
on a similar space and time scale as us would be the only thing that
we could have the hope of interacting with. The progression of life
on Earth as a whole apparently strives to fit more and more complexity
into the spaces it is able to fill. 

\begin{table}[t]
\begin{tabular}{|r|l|l|}
\hline 
\textbf{\scriptsize Category}&
\textbf{\scriptsize Current Interfaces}&
\textbf{\scriptsize Potential Future Interfaces}\tabularnewline
\hline
\hline 
\textbf{\scriptsize Physical}&
\multicolumn{1}{p{0.3\columnwidth}|}{{\scriptsize Driveway, Parking, Mailbox}}&
\multicolumn{1}{p{0.3\columnwidth}|}{{\scriptsize Driveway, Automated Package Transport}}\tabularnewline
\hline 
\textbf{\scriptsize Utilities}&
\multicolumn{1}{p{0.3\columnwidth}|}{{\scriptsize Electricity, Gas, Water, Sewage}}&
\multicolumn{1}{p{0.3\columnwidth}|}{{\scriptsize Electricity, HVAC, Fuel (Gas, Hydrogen), Water, Sewage}}\tabularnewline
\hline 
\textbf{\scriptsize Wired Communication}&
\multicolumn{1}{p{0.3\columnwidth}|}{{\scriptsize Copper / Fiber medium for Telephone, Cable TV, Internet}}&
\multicolumn{1}{p{0.3\textwidth}|}{{\scriptsize Junction Box, redundant trunks}}\tabularnewline
\hline 
\textbf{\scriptsize Wireless Communication}&
\multicolumn{1}{p{0.3\columnwidth}|}{{\scriptsize Broadcast Radio/TV, Cellphone, Satellite, Wifi}}&
\multicolumn{1}{p{0.3\columnwidth}|}{{\scriptsize distribution points to common aerials, satellite dishes}}\tabularnewline
\hline
\end{tabular}
\caption{Municipal home interfaces}
\label{tab:municipal-home-interfaces}
\end{table}

If we drew a control volume around an ecosystem, we'd find that it
functions as an engine that harnesses existing energy gradients in
order to further decrease the entropy of its local area. Through continuing
that progress, we've begun to expand the boundaries between which
objects of vastly different scales can interact. Lately we've been
peering into the inner workings of relatively tiny, fast computing
devices, which will soon be governed increasingly by subatomic interactions
between quantum particles, which in turn affect what we do with our
lives. That's amazing. Someday soon, we also expect that the tiny
electrical processes that occur in our microchips may go on to help
us alter the courses of celestial bodies, perhaps to allow us to produce
some kind of pronounced impact (or avoid an impact) in the cosmic
ballet of planets. But for now, one of primary (although not yet fully
utilized) uses for our microprocessing technology often is the guidance
of the course of our vehicles and information delivery systems.

\vspace{0.15 truein}\noindent
{\bf Influential Literature.}
The specific concept of the arcology was first introduced in the 1950s
by architect Paolo Soleri as the ultimate urban planning solution
to the problems of metropolitan growth\cite{soleri}. Continuing trends
in the expansion of metropolitan areas have contributed to explosive
growth of low density suburban sprawl, the decay of inner city urban
areas, and finally the indiscriminate destruction of natural environments
to make room for a human habitat system which is increasingly less
efficient, convenient, and aesthetically-pleasing. The concept of
the arcology attempts to reverse those trends by providing a compact
city infrastructure that works well and manages to reprocess most
of its waste before returning material back to the environment. 

What exactly \emph{is} an arcology by definition? Featured in several
science fiction works as the cities of the future, an arcology is
more than just a structure or a ``superbuilding''
that contains everything you would expect to see in a current city.
The arcology integrates living spaces and working spaces with transportation
systems that connect it all together.
As already noted, one of the fundamental differences
between arcologies and conventional cities is the emphasis on the
effective use of the vertical dimension in city planning. An arcology
design would strive to make use of several horizontal planes, whereas
current urban planning focuses more on zoning commercial / residential
/ industrial through processes that result in a more ad hoc placement
based on situational needs at the time. Another distinguishing characteristic
is the arcology's roots in urban agriculture, meaning deliberate collection
and reprocessing of waste byproducts. The arcology might simply be
described as what a city would look like if it was designed from the
start by competent systems engineers (of course, a feat easier said
than done). 

In 1978 George Dantzig and Thomas Saaty (fathers of Linear Programming
and the Analytic Hierarchy Process, respectively) got together to
write \emph{Compact City} \cite{compactcity},
providing a compelling vision on how this
human habitat would work from a technical standpoint.
This fascinating book contemplates the feasibility of
constructing a livable city of between a
quarter million to 2 million residents within a 2-4 square mile, 4-8 level superstructure.
Their proposal addresses many social and financial factors as well as provides major
engineering design elements and outlines the
major physical characteristics of their ideal proposed layout.

\emph{The Modern Metropolis} consists of a series of Hans Blumenfeld's
essays and articles on urban growth vs. urban planning\emph{\cite{modernmetropolis}.}
These treatises generalize how cities have developed and evolved over
the decades and centuries, and suggests some design principles for
sustaining growth over time. These insights into how to cope with
the forces that incrementally shape cities and inevitably stress them
beyond their initially planned limits reinforce some of the ideas
for flexibility provided by Dantzig and Saaty's design.

\vspace{0.1 truein}\noindent
{\bf Arcologies in the Media.}
A good experiment in closed-system sustainability is
Biosphere 2 \cite{biosphere2}.
Unfortunately, its primary experiment was widely regarded by the public
as a failure\cite{biospherefailure,biosphereaish}. The facility has
since come under the management of Columbia University as a research lab.

The closest present-day developments resembling arcologies are scattered
around the world in various stages of completion. The truest to spirit
arcology project in existence would be Arcosanti and Cosanti, the
experimental communities arranged by architect and founding father
of the \char`\"{}Arcology\char`\"{} concept Paolo Soleri himself\cite{arcosanti}.
These reduced scale experiments in the Arizona desert are currently
reported to be hovering around 5\% complete after 30 years of development.
Like the Biosphere 2, this development has shifted in focus into an
urban laboratory\cite{arcosantiacrl}.

While this apparent lack of enthusiasm and success paints a somewhat
bleak outlook, the influence of these spearheading projects is definitely
spreading. Large scale proposals have been cropping up more frequently,
especially in population-dense Asia. Predictably, the Chinese have
a keen interest in the arcology concept, both for expanding high-density
urban areas\cite{frick}, and also in the form of constructing sustainable
communities that would address their growing problem with semi-rural
slums\cite{ecodesigns}. Several Chinese and Japanese design firms
have been promoting various skyscraper approaches, such as the Ultima
Tower\cite{tsui}, Tokyo's Sky City\cite{takenaka}, and the on-hold
Tokyo Millennium Tower\cite{millenniumtower} (the latter two are
covered in Discovery Channel documentaries\cite{TokyoSkyCity,TokyoMillenniumTower}).
Arcology.com has a collection of other notable works and proposals\cite{arcology.com}. 

While excitement about radically redesigning urban forms hasn't quite
taken off in practice, other environmentally-friendly initiatives
have taken its place. Several publications focus more on modifying
the design goals of current city planners to incorporate more alternative
forms of transportation. The book and accompanying website Carfree
Cities presents several concepts and examples that make public transit
and areas more pedestrian and biker friendly. The author has a particular
affinity for Venice, and provides that city as a model for low impact
multimodal transit\cite{carfreecities,carfree}. Most contemporary
urban revitalization works take this track of advocating increased
use of multimodal transportation in current city design to cope with
the strains of present-day metropolitan area growth. Many formerly
suburban towns have already been pursuing more pragmatic policies
encouraging higher-density mixed-use development. These philosophies
go under the monikers of {}``New Urbanism'', {}``Smart Growth'',
or {}``Transit Oriented Design/Development''. For example, following
successes in implementing this pattern in Rosslyn and Silver Spring\cite{epasmarthgrowth}
in the Washington DC metropolitan area, plans are underway to build
higher density mixed-use population centers off of existing transit
stations in Vienna\cite{viennagrowth,viennabattle} and to extend
transit to existing office and residential spaces in Tysons Corner\cite{tysonsplan,Etlin2004}.
We'll likely see more of this type of development in the near future,
especially seeing as how the Supreme Court has recently ruled to allow
private homes to be seized for mixed use and other commercial development\cite{eminentdomain}.
Neuman cautions that higher density and other Smart Growth policies
alone will not guarantee that we will meet the goals of sustainable
development or even represent progress relative to previous development
patterns, providing some necessary definition in his article {}``The
Compact City Fallacy''\cite{compactcityfallacy}.

\section{Modeling and Design of Urban Environments}

What makes a city special compared to a cluster of businesses and residences?
Hans Blumenfeld \cite{modernmetropolis} argues that a metropolitan area
attracts corporations and residents with highly specialized skill sets.
Also, as the population grows, a wider variety of niche businesses
can sprout up and sustain themselves while catering to a relatively
small segment of the market.
So by this consideration, a good metropolitan area draws businesses
and populations to it by maximizing the diversity
and variety of specialized skills and jobs.
See Figure \ref{fig:Population-Skill-Distribution}
for a summary of these trends.
A more developed metropolitan area (represented by the green shaded
area compared to the blue shaded area) would have more positions requiring
advanced degrees, as well as offer more variety in terms of restaurants,
services, etc.

\begin{figure}[p]
\epsfxsize=4.0truein
\centerline{\epsfbox{figures/PopulationDistribution.eps}}
\caption{Population Skill Distribution
\label{fig:Population-Skill-Distribution}}
\vspace{0.30 truein}
\epsfxsize=4.0truein
\centerline{\epsfbox{figures/Geography.eps}}
\caption{Geographical Distribution}
\label{fig:Geographical-Distribution}
\end{figure}

Geographically, as cities grow in population, they often grow ``outwards'' in
area before they growing ``upwards'' in density.
As noted in Figure \ref{fig:Geographical-Distribution},
this typically follows a pattern of {}``fingers of development''
that grow outwards from the urban core along
established transportation corridors such as highways or waterways.
The result is that most metropolitan areas
eventually become victims of their own success.
Drawing more diverse and skilled population eventually increases
their geographical size towards a point where a resident of the city
can no longer access all of the resources the urban area has to offer due to congestion.

\vspace{0.1 truein}\noindent
{\bf Role of Transportation Networks in Urban Environments.}
Most of our interactions with the urban environment that we live in,
such as going to work, catching a bite to eat, or (unfortunately)
even going out for a hike, involve transportation and delivery networks.
These systems take many forms, ranging from various ground, air, and
subterranean transit networks to power, water, and even information
distribution pipelines that feed directly into each of our homes.
Much of this infrastructure is put in place with funding or regulation
from government agencies at national, state, and local levels. During
times of rapid modernization, traditional governments can be a bit
slow in figuring out what infrastructure to invest in.

\vspace{0.1 truein}\noindent
{\bf Urban Design from a Systems Perspective.}
An advantage to designing cities from the complete-systems perspective
of an arcology is that it forces you to take all scale levels -- national,
metropolitan, urban, neighborhood, personal -- into account in the
design. This would allow the arcology to transition better as new
technologies evolve and are put into place. The physical aspect of
an arcology is predicated on a municipal {}``hyperstructure'' which
could be sectioned off for residential, commercial, industrial, and
civic use. The sectional lots would have tightly integrated people
and package transportation in addition to the standard complement
of water, utilities, and a more minimal road network.

On the {\it national level},
arcologies would be constructed to connect
well to other cities, with effective transportation and distribution
systems and low transit times to most places. Current cities tend
to have suboptimal transportation facilities. Many cities originally
sprouted up around ports by major waterways, where maritime shipping
accounts for over 90\% of the tonnage of U.S. international imports
and exports\cite{GAO-02-775}. However, domestically we move freight
predominantly by truck\cite{BTSmodes}. The United States has invested
heavily in the interstate highway system. Around many cities these
get tied up in rush hour congestion, resulting in delays and waste
throughout. Airports are usually built too far from the city to connect
easily to mass transit systems, and eventually get enveloped (and
subsequently throttled) by suburban growth after which they become
a noise nuisance to residents. 

On the {\it metropolitan level},
rush hour congestion itself is an abomination
that any commuter would readily identify with. We must look terribly
silly to outsiders, repeatedly stressing our transit infrastructure
past the capacity limit where it ceases to be effective. We tend to
want to commute simultaneously simply to be in sync with everyone
else - even those whom we don't even need to deal with during the
workday. 

The U.S. metropolitan growth paradigm of roughly the last half-century
has been characterized by suburbanization. Affordable housing seems
to be in such short supply and fuel prices had been so low that many
chose commute into job centers from suburban or exurban towns 30,
60, 90 miles away. Financial policies strongly encourage citizens
to purchase homes and enter into mortgage agreements. This provides
economic stability in the workforce, helping to affix them down in
a geographic area and ensure they stay gainfully employed to keep
up with mortgage payments. However, in today's increasingly unstable
job market, this policy can have adverse effects as a workforce with
impaired mobility will not have as much flexibility to take on employment
that maximizes their skill set.

So as more massive superhighways are built to relieve the strain on
the original interstate connectors, more suburbanites continue to
sprawl out along these new corridors. After a certain point, the ratio
of space allocated between highways and developable, livable area
becomes saturated to the point where we get diminishing returns from
building more roadways. Highways take up a lot of space, and when
we start to pack those highways close together, we end up spreading
out actual useful land into isolated pockets nestled between interchanges.
Many cities have more land area allocated to paved roadways than space
for humans\cite{compactcityfallacy}.

To their credit, automobiles are certainly the most flexible mode
of transportation. All you need is a slab of pavement or even gravel
connected to the road network, and you have an interface to the intercontinental
road transportation network. Compared to the equipment you'd need
to interface with the municipal power grid or water/sewer lines, this
slip of asphalt is likely one of the simplest yet most capable ways
of moving people and goods to and from your home. However, when be
build cities almost exclusively around automotive transport, we end
up losing a lot of what makes dense cities good for people and sustainable
for the environment. Cars act as a multiplier to the amount of space
each person takes up. Not only do you need a driveway space to park
each person's car at their home, but also a space reserved at their
work, as well as some shared spaces at all of the shops and venues
at which they'd possibly spend time. Add to this the ganglia of roads
connecting those spaces together, spacious service stations, and shoulders
and extra lanes for safety and additional peak capacity, and we find
that our cities have vastly outgrown the human scale. Looking down
at our houses from an aircraft, we'd see more land covered by pavement
reigned by cars than for buildings and establishments to be enjoyed
by people. A well designed city would achieve higher density for people
by introducing transit alternatives allowing them to go directly between
home and work. Park-and-Ride initiatives connecting to mass transit
accomplish little in regards to land utilization, since they simply
the parking lots further away from the workplace. In an urban complex
with sufficient transit, people should only need to use their cars
to leave the city, but rely on municipal transit to move people and
goods within the city.

On the {\it personal level} much of the home infrastructure for living
does not have flexibility for change. We are still using much of the
same basic physical interfaces developed over a century ago for power
and voice communications. Additional systems have sprouted on top
of and alongside these networks, such as DSL over existing telephone
wiring, cable television, and various wireless and satellite networks.
Add to that various combinations of buried water mains, sewage systems,
natural gas pipelines, and perhaps we might begin to appreciate the
need for developing more flexible and maintainable living facility
distribution and interconnect standards. The new standard interconnects
would provide room for expansion and maintenance, supporting the adoption
of emerging new infrastructure networks, and giving us greater flexibility
in reusing older homes and living spaces. Such standards help reduce
the barriers to market entry, allowing economical deployments of existing
upgrades such as fiber-to-the-premises, or even some things for which
markets haven't really been created for yet, such as fully-automated
package delivery systems or centralized HVAC services.

\section{Simulation and Optimization of Urban Environments}

\vspace{0.1 truein}\noindent
{\bf Simulation of Operational Concepts.}
Simulation is one tool that can help quantify the benefits of
different operational concepts,
which in turn can help answer questions about design options. 
A common engineering practice is to first document and construct a
baseline validated simulation of the system you have in place, then
extend the simulation with new proposals for changes to equipment
or operation. After an engineer has evaluated the performance
of different options, he/she could make a decision,
implement the change, and then revalidate the simulation to make
sure their model matches the performance of the actual system.
Unfortunately, few municipalities maintain validated
simulated representations of their jurisdictions, much less use them
as decision making tools, deferring more towards the use of surveys
and standalone analytical teams. Building such a tool would not only
give them better access to information about physical arrangement
the performance of their existing town, but could grossly cut down
on the arguments and political delays incurred when properly used
as a {}``vision communication tool'' to the populace.

\vspace{0.1 truein}\noindent
{\bf Simulation as a Decision Making Tool.}
Several initiatives are currently underway
to rethink the way metropolitan areas are designed.
This simulation modeling and analysis framework
can provide a design planning and evaluation tool to assess several
integrated mass transit network topologies to help identify and accelerate
the worthwhile changes.

The use of simulation as a decision-support tool could help avoid
or at least temper some of the larger controversies over the past
century of rapid technological change. The history of our infrastructure
has been peppered with some epic and ultimately costly battles over
different modes of transfer, such as the turn of the century Edison
- Tesla battle to establish AC or DC as the power delivery standard\cite{ACDC}
or the politicized finger pointing over whether GM was duly responsible
for taking control of streetcar operations in the 20s in order to
dismantle them in favor of GM-manufactured buses\cite{Slater97,Cosgrove05}.
Having detailed records of the simulations used to provide hard data
on which broad policy decisions are based could help justify your
decision later. With more options pushed by several technology firms,
it should be more important than ever to be able to determine the
selection of major wired or wireless communications infrastructure
or transit modes based on available technical data, and not on which
company has the best connections to the civil servants responsible
for municipal decision making.

Ultimately, if this were to evolve into a fully-featured urban simulation
tool, it could be used as a rapid prototyping environment for proposals
to system changes big and small. When this functionality matures,
a municipality might require a simulation-based analysis to accompany
any new infrastructure proposal as part of a gateway approval process.
As standard patterns are built up, the sim framework may morph into
a design tool, replete with a library of open-source blueprints, guidelines,
and standards (as well as customizable sections) to that can be deployed
to achieve a development goal. Furthermore, as the process becomes
automated, it might incorporate more direct civil input, turning review
and evaluation of problem areas and proposals into something of an
experiment with alternative direct digital democracy governance, with
which the citizens can interact with as something of a hive mind.
Or so goes the vision.

\vspace{0.1 truein}\noindent
{\bf Urban Simulation in the Media.}
Previous well-known works that tackle the task of urban simulation
includes two series of open-ended games from Maxis (now part of Electronic
Arts) that approach the problem from different scales: SimCity and
The Sims. Certain versions of SimCity (2000 and 3000) even had arcology
elements in them, although since they were entirely self-contained,
they really did little for the game other than to allow you to boost
your population without having to provide additional infrastructure.
To some extent, these games could be used to experiment with different
urban or residence layouts, but they primarily pattern themselves
after common current day paradigms and lack the flexibility needed
to really turn its simulated environment upside down. Hopefully they
do serve to influence the next generations of urban planners, who
might come to expect and demand some of the timely command and control
interfaces coupled with instantaneous reporting of the city's condition
and resources. Beyond that, there is not much published in the way
of complete city and/or lifestyle simulation. This is probably partly
because most of this analysis can be done more simply using historical
data tracked by government statistical agencies, and because most
of the simulation writers are more busy simulating more interesting
things such as data\cite{ssfnet} and transportation networks\cite{CITYSIM}.

\vspace{0.15 truein}\noindent
{\bf Optimization of Mass Transit Operations.}
The goal of the optimization tool embedded within the simulation component
is to demonstrate a flexible modeling scheme that could
investigate the potential effectiveness of various mass transit topologies
and strategies, especially with regards to:

\begin{description}
\item{\bf 1.}
The distribution of and various loads generated by work nodes and
residential nodes.
\item{\bf 2.}
The size and connectivity constraints of various shared vehicle networks
shuttling people and goods between nodes.
\item{\bf 3.}
The ability for the passengers and cargo to make transfers between
different vehicles as well as modes of transit.
\end{description}

\vspace{0.1 truein}\noindent
As the urban area grows, we attempt to preserve an ideal population
density while also preserving the practical reach of the
transit system to prevent fragmenting the city.
For civic planning authorities, this traditionally involves zoning
and building out roads and utilities.
At some point along the city's growth, they might consider the efficiencies
of building infrastructure based on a futuristic arcology hyperstructure
in order to meet their urban development goals in a compact physical package.

\section{Scope and Contributions of this Work}

Chapter 2 describes the formulation of a generic arcology system model --
the result is a series of conceptual templates represented as classes
and relationships among classes.
Chapter 3 covers many of the practical details one needs to consider
in creating discrete event simulation environments with SimPy.
Chapter 4 is all about the system model.
Chapter 5 contains simulation scenarios and parametric analyses for
various mass-transit topologies.
The project conclusions and opportunities for
future work are covered in Chapter 6.

\vspace{0.1 truein}\noindent
The contributions of this work are as follows:

\begin{description}
\item{\bf 1.}
A hierarchical level-of-detail organization that allows available
data from both top-down parametric models to interact with data generated
from clusters of detailed simulation objects. This allows us to seed
detailed objects in a subsystem using available aggregate data 
and compare it to data generated by tallying up the individual contributions.
The hierarchical organization also makes the simulation
easier to partition across distributed compute nodes.
\item{\bf 2.}
Definition of a data interchange schema between elements of a multi-modal
transit infrastructure. The communication provides just enough information
about each piece of passenger, cargo, vehicle , and connectivity graphs
and defines minimal interfaces to allow them to report to and receive
suggestions from a global transit optimization engine.
\item{\bf 3.}
An inherent focus on meeting the needs and goals of the inhabitants.
Many transportation simulations focus on maximizing throughput or
minimizing delays or fuel expenditure. However, these metrics may
not serve to help evaluate the layout of the urban area itself. This
simulation infrastructure would ideally be used to measure the effectiveness
of optimizing the layout of an urban area to reduce the need to load
the transit infrastructure with commuters, people running petty errands,
and other frequent but necessary tasks.

$\eta=\frac{GDP}{E{\scriptstyle _{direct}}+E_{sustinence}}$

An ideal city would have a
higher {}``efficiency'' ratio, tracked by an admittedly somewhat
elusive {}``productivity'' metric divided by the amount of energy
needed to produce and nominally sustain it.
\end{description}

\vspace{0.1 truein}\noindent
A simple multimodal mass transit optimization solver coupled to the
simulation attempts to create a demand-responsive fleet schedule for
several types of defined vehicle types that service transit networks
within the sim. This tool aims to provide a quasi-optimal means to
transport people and goods around within city clusters.
