\section{INTRODUCTION}

	Workplace accidents in the mining industry reduce production,
	increase costs, and result in debilitating injuries or death to
	mine workers.	  Accidents are a major concern in day-to-day
	mining operations and are expensive in terms of cost and employee
	morale.

	One of the most important tools for on-the-job accident prevention
	is worker training.  However, the cost of accident prevention
	training is high, particularly when the training method attempts to
	provide a realistic representation of risks associated with
	mining vehicle operation and the proper  techniques that
	avoid or manage those risks.  Preparing  video demonstrations,
	conducting safety training tours of work sites, and conducting
	on-site safety briefings are all effective training tools. But
	these methods can be expensive and disruptive to daily operations.

	Virtual reality (VR) is a technology for developing training tools
	that offer an excellent approach to reducing both job accidents
	and the high cost of training.	     Two such tools developed at
	the University of Nevada are the Mine Vehicle Inspection Simulator
	(MVIS) and the Mine Vehicle Driving Simulator (MVDS). These
	tools address the training issues of pre-operational vehicle
	inspection and driver training.

	These products have been developed using PC-based real-time
	3D graphics and cutting edge VR input devices. These products,
	designed for the Microsoft Windows NT platform, offer mining
	companies a cost effective alternative to traditional training
	methods.

	In Section~\ref{sec:MVIS} we discuss the pre-operational vehicle
	inspection and the development of the Mine Vehicle Inspection
	Simulator as well as its features and future improvements that
	we are planning.  In Section~\ref{sec:MVDS} we present the
	Mine Vehicle Driving Simulator and discuss how it can assist
	in operator training.  This is followed by conclusions in
	Section~\ref{sec:conclusions} and acknowledgments.

\section{PRE-OPERATIONAL VEHICLE INSPECTION}
\label{sec:MVIS}

	Mining companies around the world agree that pre-operational
	vehicle inspections are effective in decreasing haulage-related
	accidents. Performed prior to taking a vehicle into the
	field, inspections by the vehicle operator identify hazardous
	damages that occur from normal use. The cost benefits of these
	inspections are twofold. First, they make the workplace safer by
	keeping faulty equipment out of the field and helping to reduce
	haulage related accidents. Second, pre-operational inspections
	extend vehicle longevity as an additional component to vehicle
	maintenance routines. However, training employees to correctly
	perform pre-operational inspections is expensive.  Traditional
	training methods such as written material, videos, seminars,
	and live inspections suffer from one of two problems. Either
	the training method poorly conveys critical information (written
	and spoken) or is extremely expensive to conduct (live vehicle
	inspections). The need for a cost-effective training method
	appropriate for teaching pre-operational inspections has led
	to the development of the Mine Vehicle Inspection Simulator
	(MVIS). By using state of the art PC and VR technologies,
	MVIS combines the learning experience gained from live vehicle
	inspections with the cost effectiveness of written material and
	video training aids.

	     \begin {figure}
		\centerline{\psfig{figure=figs/MVIS2.ps,width=112mm}}
		\caption{Screen Shot of MVIS.\hspace*{2.2in}}
		\label{fig:MVIS-SCREEN-SHOT}

	\hspace*{5pt}
	     \end{figure}

	MVIS is a VR simulation of the pre-operational vehicle
	inspection designed for mid to high-end PC-class computers
	running the Microsoft Windows NT operating system. A screen
	shot of MVIS is shown in Figure~\ref{fig:MVIS-SCREEN-SHOT}. As
	a feature-rich software package, MVIS brings together 
	PC-based computing and VR technology to offer mining companies
	a cost-effective alternative to traditional training techniques
	in terms of time, initial investment, and training effectiveness.

        The key to MVIS's effectiveness as a training tool is the virtual
        reality environment in which the trainee works. MVIS successfully
        implements virtual reality using 3D graphics and input devices
        suitable for movement in  3D space.

   \subsection{\it The Inspection Process}

	When the simulation is started, trainees are presented with
	a 3D model of a vehicle.  Using the input device provided with
	the software, the trainee walks around the vehicle and performs
	a visual inspection. The trainee looks for parts
	that appear damaged or require a detailed inspection
	regardless of condition. To perform the inspection,
	the user identifies an item of interest by selecting it with the
	mouse. This action causes a window (dialog box) to be 
	displayed allowing
	the trainee to type in inspection information. This information
	would be a description of the process used to inspect that
	part.
	This information can then be used to determine if
	the trainee
		\begin{itemize}
		\item knows how to correctly identify parts of the
		vehicle that require inspection
		\item recognizes damaged parts
		\item knows the proper course of action to take in the
		case of a damaged part
		\end{itemize}
	Results are recorded by the simulator, and a report is 
	produced upon completion of the inspection. These results
	can then be reviewed by a qualified trainer for 
	evaluation purposes. Additional information recorded by the
	simulator includes the total time taken to perform an inspection,
	position in the scene where the trainee inspects an object and the
	number of attempts made to inspect each part.

   \subsection{\it Value-Added Features}

	During development of MVIS, several training professionals
	from the mining industry contributed ideas and suggestions for
	improvement. We have taken many of these suggestions and
	have either integrated them into our current implementation of
	MVIS or are planning to incorporate them in future versions.

	\subsubsection{\it VR interaction}

	The key to effective virtual reality is the ability to draw
	users into the simulation.  By making the simulation as real
	as possible, users will get more out of their experiences in
	VR. One major area of VR that affects its effectiveness is
	the interface used for movement in 3D space. MVIS 
	utilizes an input device more suitable for movement in
	3D than traditional computer input devices.  Traditional computer
	input devices (mouse, track balls, touch pads, and keyboard)
	are ineffective for moving in 3D space 
	because these devices limit movement to two dimensions in a single
	action. For example, the arrow keys on a keyboard can only be
	used to move in a single direction. This is fine for walking,
	but how does the user look down or up while walking forward? In
	order to change the viewing direction, the user must either
	use a different key or a combination of keys. The same applies
	when using a mouse-type device (mouse, track ball, joy stick). 
	These devices create a complicated
	user interface for 3D movement which can be confusing and
	discouraging. To alleviate this problem, we decided to take a
	different approach and use a 6-Degree-of-Freedom (6DOF) input
	device. As name implies, a 6DOF device allows for six types
	of movement: movement along the three axis (X, Y, Z)
	and rotation around these axis. Using this device, users can
	easily perform complex movements  such as
	moving forward while scanning for obstacles
	on the ground or for those hanging from a ceiling. Moreover, 
	all actions
	are performed using a single, intuitive, hand-held unit
	\cite{spacetec}.
	An example of a person using such a device with MVIS is shown 
	in Figure~\ref{fig:person}.

		\begin {figure}
   \centerline{\psfig{figure=figs/MVIS_6DOF.ps-bw,height=4in}}
   \caption{An Inspection with a 6DOF Device (SpaceOrb [6]). \hspace*{0.6in}}
		   \label{fig:person}
		\end{figure}

	\subsubsection{\it Inspection dialog box}

		\begin {figure}[b]
   \centerline{\psfig{figure=figs/MVIS_inspdlg.ps,width=112mm}}
	   \caption{MVIS with Inspection Box Open.\hspace*{1.3in}}
		   \label{fig:MVIS-INSPECTED-PARTS}
		\end{figure}
		
	The inspection dialog box in MVIS 
	(shown in Figure~\ref{fig:MVIS-INSPECTED-PARTS}) is a window 
	that allows
	trainees to enter inspection information for a vehicle part. In
	the first implementation of MVIS, this dialog box presented
	the user with a list of actions they could perform on a part
	being inspected. Mining professionals suggested that the dialog
	box be changed to query trainees for a description of how they
	would inspect a part rather than prompting them for a decision
	based on a list of options. This change was made based on the
	following reasons:
	\begin{enumerate}
	\item Providing a list of options to choose from is equivalent
	to a taking a multiple-choice test. Therefore, an individual 
	with good reasoning skills could deduce the correct 
	action. This does not give the trainer an accurate measure of 
	the trainee's knowledge.
	\item Inspecting an individual part often involves a process 
	rather than a single action.  Multiple-choice 
	tests are insufficient in these situations.
	\end{enumerate}
	Therefore, we re-implemented the inspection dialog to contain
	a text box in which trainees can type a description of how they
	would inspect the part selected. This could include either the
	process needed to inspect a particular part or what to look for
	when inspecting that part. Furthermore, this modification allows
	MVIS to support inspection processes specific to each
	mine site.


	\subsubsection{\it Lost in space}

	During preliminary tests of MVIS, the scene in which a user
	was placed contained no visual clues (such as sky, ground,
	and horizon) that could be used to maintain orientation.  If a
	user got lost, it was difficult to regain orientation. Without
	a horizon, the user had no idea which way was up. With the
	addition of scenic elements, navigation in the VR world was
	much easier. However, we felt the addition of a second visual
	perspective would be useful to help users determine their
	position in complex scenes where they might be required to
	navigate between several landmarks. For these reasons, the Position
	Locator view was added to the user interface of MVIS. The Position
	Locator is a separate window that views the scene from a third
	person perspective, as shown in 
	Figure~\ref{fig:MVIS-LOCATION-WINDOW}. 
	An icon is used to represent the position
	and viewpoint direction in the scene. The Position Locator can
	toggle between two default viewing modes, top-down and front view,
	for convenience and ease of use, or the user can freely rotate
	the entire scene in the viewer to create their own view from the
	best possible vantage point. The Position Locator can be opened
	and closed throughout an inspection at the user's discretion.

		\begin {figure}[h]
   \centerline{\psfig{figure=figs/MVIS_poslocate.ps,width=112mm}}
	 \caption{MVIS with the Position Locator View Open.
		\hspace*{0.5in}}
		   \label{fig:MVIS-LOCATION-WINDOW}
		\end{figure}

	\subsubsection{\it Inspected part list}

	In real inspections, inspectors are often required to maintain
	an inspection log. However, because MVIS is computer based, the
	simulation records details of an inspection using the Inspection
	Dialog box. As an additional tool to aid trainees using MVIS,
	an Inspected Part List is provided. The Inspected Part List is a
	separate window that floats on top of the application and maintains
	a list of parts the trainee has inspected. This window also
	allows easy access to inspection details on a part-by-part
	basis so trainees can review their work before completing 
	the inspection. The Inspected Part List can be opened or closed
	throughout an inspection.  An example of the Inspected
	Part List can be seen in Figure~\ref{fig:MVIS-SCREEN-SHOT}.

	\subsubsection{\it Inspection administration}

	Although MVIS is primarily a training tool, it is equally
	effective for vehicle operator evaluation. For this reason,
	it is important that trainees using the software are unable
	to tamper with scenario configurations after an inspection has
	begun in an attempt to gain an advantage on their performance
	evaluation. Several safeguards are built into MVIS to ensure that,
	once an inspection has begun, all user interface elements (menus
	and buttons) that gain access to scenario configurations are
	locked and cannot be accessed until the inspection is complete.

	\subsubsection{\it Vehicle and vehicle configuration flexibility}

	Another benefit of MVIS is its configuration
	flexibility. MVIS uses a standard graphics file format to
	represent vehicles in VR. With this feature, a mine company can
	provide inspection models for every type of vehicle
	employees would encounter at a particular job site. Another
	feature of the file format used in MVIS is part configurations
	for individual vehicle components. In order to use this feature,
	defective part versions of inspectable parts must be defined in the
	inspection model. An example of a defective part might be a leaky
	or cracked strut. 
	Each part in a vehicle can have an unlimited number of defective
	part versions. At runtime MVIS uses vehicle configuration information
	to determine which defective part version will be used when the model
	is displayed. Data that defines a vehicle configuration
	is called a scenario and is stored in a file that accompanies a
	model. This file can store any number of scenarios for the vehicle
	it accompanies. To select a scenario at runtime, a menu option
	is available prior to starting an inspection that allows the MVIS
	administrator to select a scenario.
	As a second method for defining a vehicle
	scenario, a scenario configuration dialog is available. This
	dialog box displays a list of available parts as
	well as a list of defective part versions available for each part.
	The MVIS administrator can select individual defective parts to
	be included in a vehicle configuration.

   \subsection{\it Future Enhancements}

	MVIS is an ongoing project that is continually being enhanced
	and modified to reflect the needs of our customers and the
	latest trends in the mine safety industry. Enhancement ideas
	that we have received from mining professionals that are slated
	for addition to MVIS include improved inspection evaluation,
	proximity selection, inspection ordering, model and scenario
	customization, and an enhanced inspection dialog box.

	\subsubsection{\it Improved inspection evaluation}

	At this time, inspection results are produced in the form of a
	report. This form of performance evaluation is suitable when the
	number of inspection points is small but becomes cumbersome as
	the number of inspection points grows. To make the process
	of evaluating an inspection easier, an inspection performance
	evaluation program is in development. This program will allow
	evaluators to gain access to valuable information as quickly
	as possible using an intuitive graphical user interface. As an
	added feature, this software will also give the evaluator access
	to information that was previously inaccessible.  For example,
	the package will allow the reviewer to play back an animation
	of the path the trainee took while inspecting a vehicle. As a
	training aid, this information is useful in determining if the
	trainee is taking the most efficient path around a vehicle
	during an inspection.

	\subsubsection{\it Proximity selection}

	One of the major challenges facing mine safety trainers is
	conveying the importance of performing the actual inspection
	to new employees. All to often, vehicle operators perform
	cursory inspections and overlook important details that can
	be identified only by close examination. To help better train
	vehicle inspectors, proximity selection is being added to
	MVIS. In the current version of MVIS, objects can be inspected
	from any distance in the VR world. A bed pin on haul truck could
	conceivably be inspected from three miles away (provided the
	user can choose the part with the mouse). Proximity selection
	is a way to enforce maximum distances between the user and the
	part before a part can be selected.  In the bed pin example, the
	MVIS administrator could enforce the policy that inspectors must
	be within three feet of a bed pin before it can be inspected. The
	distance from which a part can be selected will be defined in
	an inspection scenario definition on a part-by-part basis.

	\subsubsection{\it Inspection order}

	Most mining companies design their own process for performing
	the pre-operational vehicle inspections. It is the goal of
	MVIS to accommodate as well as complement the various ways to
	perform inspections and to aid trainers in teaching the process
	of inspections. A soon-to-be-added feature of MVIS is the ability
	to enforce the order in which groups of parts are inspected. For
	example, a mine might require that the front left wheel assembly
	(strut, steering linkage, wheel, tire, etc.) be inspected
	before all other parts. However, according to mining professionals,
	it is inconsequential in what order the parts within a group are
	inspected. The inspection order allows a training administrator
	to define groups of parts, as well as an order in which the
	groups are inspected.  The unique aspect of this feature
	is that parts within a group can be inspected in any order,
	while group inspection order is enforced.  Inspection of a
	group is not complete until all parts in that group have been
	inspected. This feature will be controlled from within the
	inspection scenario definition.

	\subsubsection{\it Model and scenario customization}

	Although model data files used by MVIS are standardized,
	the composition of the model data within the file is highly
	proprietary to MVIS. Therefore, we are currently designing a
	software tool that will allow mine companies to convert existing
	CAD/CAM models of vehicles and equipment (including defective
	parts) to the format supported
	by MVIS.  This package will allow a
	scene designer to decompose a vehicle into inspectable parts and
	non-inspectable parts for use with MVIS and to identify where
	defective parts will be included in the model. This package will
	also be capable of designing and storing the scenario definition
	file for a specific model.

	\subsubsection{\it Enhanced inspection dialog box}

	One of the major challenges of providing a realistic inspection
	experience in VR is the representation of highly accurate models of
	vehicles. 
	It is difficult to obtain computer models of
	vehicles that have the kind of detail needed for performing a
	thorough inspection. These models are usually guarded secrets
	of the vehicle manufacturer. Furthermore, even if one of these
	models was available, the sheer complexity of the model would be
	beyond the capabilities of modern PC hardware to render in real
	time for VR. For these reasons, we are going to add a detail view
	to the inspection dialog box. The detail view is a subsection
	of the inspection dialog box that displays an actual picture of
	the part being inspected. This feature will help eliminate the
	need to have extremely detailed models of vehicles while still
	demonstrating to the trainee exactly what should be examined.


\section{DRIVING SIMULATOR}
\label{sec:MVDS}

	The second aspect of mine safety training being investigated at
	the University of Nevada is driver training.  The United States
	Occupational Safety and Health Administration (OSHA) stated in
	1995 that industrial trucks accidents are the second leading cause
	of fatalities in the private sector \cite{OSHA95}.  On average,
	there are 107 fatalities involving industrial trucks per year.
	The Mine Safety and Health Administration (MSHA) reports that over
	the last few years accidents involving operators of off-highway
	haulage vehicles in surface ground mining operations have
	resulted in between 15 and 20 fatalities per year and between
	350 and 450 near fatalities per year \cite{MSHA98}.

	Our team has developed a prototype
	simulator to assist in driver training appropriate to
	the surface mining industry. Our prototype package, the Mine
	Vehicle Driving Simulator (MVDS), is an attempt to determine the
	requirements of such a simulator with respect to technological
	challenges of software development and customer requirements. The
	prototype development of MVDS focused on two key areas: driving
	simulation and pit hazard simulation. MVDS is designed to train
	drivers on the skills necessary to safely operate power haulage
	in an open pit surface mine. MVDS accomplishes this by simulating
	vehicle operation in an open pit mine.

	\subsection{\it Product Overview}

	\begin {figure}[b]
   \centerline{\psfig{figure=figs/MVDS.ps,width=112mm}}
	   \caption{Screen Shot of MVDS Prototype.\hspace*{1.3in}}
	   \label{fig:MVDS-SCREEN}
	\end{figure}

		When a person begins their driver training with MVDS,
		they are seated in front of a computer screen on a desk
		with a steering device.  MVDS uses a consumer grade
		steering device with a steering wheel, simple gear shift,
		and gas and brake pedals.  On the screen, the trainee
		is presented with a 3D model of what they would see
		out of the front windshield of their vehicle when driving in
		a mine, as shown in Figure~\ref{fig:MVDS-SCREEN}.  
		MVDS can convert files containing mine layout
		data produced by mine software to a format it can use.
		This allows the trainee to view the pit in which they
		will be driving.

		The trainee is to drive around the mine (possibly
		fulfilling some task) while observing the ``rules of
		the road.'' These rules for mine vehicle operators
		differ considerably from Department of Motor Vehicle
		regulations for highway vehicles. For example, in most
		mines, operators are required to drive on the left rather
		than the right side of the road. 
		A simple representation of a dashboard is displayed at
		the bottom of the screen.  The dashboard shows the trainee
		several gauges including speedometer, gearing indicator,
		and tachometer.  The dashboard in combination with the
		steering device give the trainee a feel for where some of
		the gauges are located.  

		As the trainee drives, he/she is presented with hazards
		to avoid. MVDS supports two types of hazards, static
		and dynamic.  Each presents the trainee with different
		types of situations to deal with. Static hazards, such
		as parked pickups, can be hard for trainees to see.
		Dynamic hazards, such as moving people, present trainees
		with the problem of trying to figure out where the hazard
		will be moving and whether a change course is needed to
		avoid the hazard.


	    \subsection{\it Product Customization}

\begin {figure}[b]
   \centerline{\psfig{figure=figs/mvdss-finished.ps,width=112mm}}
   \caption{A Completed Scenario Created in MVDS Setup.\hspace*{0.3in}}
   \label{fig:MVDSS-COMPLETED}
\end{figure}

		Once the first prototype of MVDS was completed, the
		trainers that used it asked whether training scenarios
		could be added.  In order to allow on-site trainers to
		create new scenarios, we have developed the MVDS setup
		program, shown in Figure~\ref{fig:MVDSS-COMPLETED}.
		This program will allow on-site trainers to make new
		scenarios for trainees to navigate as the mine and
		operating regulations change.  It can also be used to
		familiarize current vehicle operators with pits with
		which they are not familiar.  The trainers will be able
		to change the mine by moving shovels, loaders, etc.
		and by closing routes the trainee may have used in 
		the past.

		When designing a scenario, the trainer can add static and
		dynamic hazards.  To place a hazard, the  trainer selects
		a location in the mine and chooses a hazard to go in
		that location.  If the
		trainer is placing a dynamic hazard, the location is a
		path (or series of locations) the hazard will follow at
		a pre-defined speed.  Figure~\ref{fig:MVDSS-DYNAMIC-PATH}
		shows the placement of a dynamic path in a mine scenario.
		The bubbles show the path being selected by the trainer
		for a dynamic hazard.  These can be turned on and off
		in the setup program.  Any object that is modeled in an
		Open Inventor-compatible file format can be added as a
		static or dynamic hazard.  We currently provide cones,
		people, pickups, loaders, and other vehicles.

\begin {figure}
   \centerline{\psfig{figure=figs/MVDSS_dynamic_path.ps,width=112mm}}
   \caption{Creation of a Dynamic Hazard Path.\hspace*{1.1in}}
   \label{fig:MVDSS-DYNAMIC-PATH}
\end{figure}

		Once a scenario is fully configured, this information
		can be saved to a file which is used by MVDS.  Scenarios
		can be modified to reflect changes in the mine and
		MSHA regulations over time.  This gives trainers the
		flexibility to build a library of scenarios used to 
		accurately test the skills of vehicle operators.

	\subsection{\it Future Enhancement}
	
		MVDS is an ongoing project that is continually being
		enhanced and modified to assist our customers in safety
		training.  We have begun the design of enhancements
		including an improved physics model, improved simulation
		interaction, an expanded feature set, and a distributed
		architecture that will allow multiple drivers in the
		same pit.

	    \subsubsection{\it Improved physics model}

		One of the key components of our next implementation
		of MVDS receiving the most attention is the physics
		model. The physics model of the simulation is responsible
		for interfacing user input with a simulated physical world
		in VR. The physics model determines vehicle simulation and
		environmental simulation. Vehicle simulation simulates the
		mechanical capabilities of the vehicle itself including
		turning radius, acceleration, braking capabilities, most
		of which change depending on whether the vehicle is 
		loaded or unloaded.
		Environmental simulation is responsible for managing
		the physics of environmental conditions present in
		a mine. Environmental conditions we are considering
		adding include rain, snow, and high wind.
		These poor weather conditions greatly affect a
		driver's ability to safely operate a vehicle. For example,
		rainy weather not only reduces a driver's visibility,
		which will be selectable by the trainer, but
		also degenerates haulage roads causing vehicles to respond
		much differently than in dry weather conditions. In our
		new physics model, these examples of simulated physics and
		more will be implemented to give drivers a more accurate
		image of not only how a vehicle handles, but also how
		to safely operate a vehicle in various weather conditions.

	    \subsubsection{\it Improved interaction}

		The effectiveness of any VR simulation is directly related
		to the level of realism of its user interaction.  We can
		improve the user interaction of MVDS with  the addition
		of force feedback steering wheels.  These steering wheels
		have a motor in them to allow the wheel to be forced in
		a certain direction.  If a mine vehicle driving down a
		haul road hits a berm on the side, the steering wheel
		will be forced very hard in the opposite direction.
		With a force feedback steering wheel, we can cause the
		wheel to do the same thing in the simulation.

	    \subsubsection{\it Expanded hazard options}

		During initial evaluation, training professionals began
		to ask for more hazard selections.  We are considering
		adding proximity-triggered hazards and time-triggered
		hazards.  A proximity-triggered hazard is one that would
		appear when training vehicle moved close to it.  
		For example, when
		the vehicle approached a surveyor's truck, the surveyor
		may walk out in front of the vehicle from behind his
		truck.
		A time-triggered hazard is one that occurs at a certain
		time in the simulation. For example, a truck may begin
		moving from a parked location, or a rock slide may occur.

	    \subsubsection{\it Distributed architecture}

		To further enhance the realism of the simulation, we
		are considering creating a distributed version of MVDS
		which will allow multiple trainees to be in the same
		simulation at the same time.   The trainees will have to
		interact with each other as well as with other hazards
		that may already be in the scenario.  Trainees will have
		to deal with unpredictable behavior of other trainees,
		completely eliminating the possibility of the trainee
		memorizing the situation being presented.

		A distributed version of MVDS will also allow trainers to
		watch the trainees from a separate room, where trainees
		will not be aware of the close monitoring.  The trainer
		will have multiple views of the simulation: one of the
		entire mine, with all of the trainees' positions, and one
		shadowing a specific trainee.  When shadowing a trainee,
		the trainer will be able to get detailed information on
		what the trainee is doing.  The trainer will be able
		to see the distance between the trainee's vehicle and
		other vehicles in the area, read all of the gauges on
		the trainee's dash, and have a small window showing the
		3D model of the mine that the trainee can currently see
		out of the windshield.	  This will allow the trainer
		to monitor those trainees that are just beginning more
		carefully than the experienced ones, without hanging
		over their shoulder.

		Another advantage of a distributed version of MVDS
		will be faster reaction to user input.	By taking
		the computationally intensive portions of MVDS and
		dedicating a machine to those processes, the graphics
		will be displayed on the trainee's machine at a much
		faster rate.  This will also allow the computationally
		intensive portions to run faster as well, since they will
		not be competing with the graphics for the machine the
		trainee is using.  By separating the graphics and other
		portions, we will be able to improve the performance and
		capabilities of the entire program.

%	\begin {figure}[h]
%   \centerline{\psfig{figure=mvdss-finished.ps,width=112mm}}
%	   \caption{Diagram of Distributed MVDS.\hspace*{1.5in}}
%	   \label{fig:DISTRIB-MVDS-DIAGRAM}
%	\end{figure}


\section{CONCLUSIONS AND OTHER PROJECTS}
\label{sec:conclusions}

	Initial responses to MVIS~\cite{MVIS} and MVDS~\cite{MVDSS} 
	have been extremely positive.
	The fact that these tools have been developed
	for the PC platform has been very appealing to the mining
	industry, since most companies use this platform.

	There remains a great deal of work that can be done with
	VR in the areas of mining and mine safety.  Besides the
	enhancements to the products we have outlined in this paper,
	we are also investigating applications for underground mines.
	Our investigations would complement the research already under 
	way in the development of the Mine Emergency Response Interactive
	Training Simulation (MERITS)~\cite{MERITS} being done at the
	NIOSH Pittsburgh Research Lab.

	Mine regulations require extensive emergency training for
	underground mine personnel.  Current training programs take
	considerable time and effort on the part of miners, supervisors,
	and trainers and do not adequately prepare mine personnel to
	handle complicating factors such as blocked routes, failure
	of lighting, and reduced visibility due to smoke.	A VR
	training system would improve the convenience and quality 
	of training, allowing a mine to better equip its personnel to
	handle emergencies.  VR training would also provide rescue teams
	better training for emergencies in many mines without having to
	visit those mines for training.

	Although virtual reality simulators are not new, employing such
	simulators to reduce training costs and accident rates
	is relatively new to the mining industry.
	VR training brings together the cost effectiveness of written
	and video-based training materials with the training 
	effectiveness of practical experience.


\section*{ACKNOWLEDGMENTS}

	This work was partially supported by  Newmont Gold Co., Echo
	Bay Minerals, the Nevada Division of Industrial Relations,
	and the Mine Safety Health Administration.

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