Welcome to the inaugural issue of the GoldSim Newsletter! Starting with this
issue, we will be publishing a quarterly e-newsletter and sending it to the
GoldSim community. Our goal is to provide information to help you get the most
out of GoldSim. We also hope that the Newsletter can act as a vehicle to build
connections between users within the GoldSim community.
Each newsletter will deliver the latest GoldSim news (e.g., regarding updates
and new versions), as well as a number of regular items. This will include a
Featured GoldSim Application, tips from the GoldSim developers, a list of new
models added to the GoldSim Model Library, a list of new GoldSim Knowledge Base
articles, and a description of new features that the GoldSim Development Team
is currently working on. Each Newsletter will be archived on our website so you
can revisit old issues.
Since this newsletter is for you, we encourage you to send us your comments and
contributions. If you send us a contribution and we use it, we will acknowledge
you in the Newsletter. Send your contributions to
The GoldSim Development Team
User Conference Rescheduled to April 2002
Due to the tragic events of September 11, the 2001 User Conference scheduled for
September was cancelled. The Conference has been rescheduled to April 2002. The
Conference will be held in Redmond, Washington on Thursday and Friday, April 25
- 26, 2002. Prior to the conference, a three-day GoldSim training course will
be held for new GoldSim users on April 22-24. In addition, for existing users,
a set of FREE advanced training seminars will be held on Wednesday, April 24.
The User Conference will be a terrific opportunity for users to share
experiences with each other and with the GoldSim developers, and to provide
input for the future development of GoldSim. We hope you can attend.
GoldSim Version 7.3 to be Released by Year End
The next version of GoldSim (Version 7.3) will be released by year end. In
addition to numerous minor changes, refinements and bug fixes, this version
will have a number of important modifications and new features, including the
Expressions entered into input fields within GoldSim are now color-coded (i.e.,
output names, functions, operators, and units are displayed in different
colors). This makes expressions much easier to read (and enter).
Several elements have been renamed. An Accumulator becomes an Integrator. An
Event Generator becomes a Timed Event. A Consequence Generator becomes a
The integration algorithms for Reservoirs and Integrators (formerly called
Accumulators) have been modified and improved. Both of these elements integrate
continuous signals. Version 7.3, however, encourages users to distinguish
between the movement (and integration) of materials and the movement (and
integration) of information. A Reservoir is intended to integrate materials and
represents a "stock" of something (e.g., water, widgets). An
Integrator simply integrates a signal (information). Because material and
information movement are conceptually and mathematically distinct (materials
are conserved, information is not), these are represented by two separate
Two powerful new Delay elements have been added: a Material Delay and an
Information Delay. These delay elements delay continuous signals (which can
optionally also be dispersed in transit). For example, to simulate the movement
of water through the unsaturated zone you would specify a flow rate into the
delay, the mean travel time required to move through the zone, and the degree
of dispersion in transit (which would be 0 for a plug flow system). The output
of the Material Delay would then be a delayed and dispersed flow rate. Material
Delays can be used for a wide variety of systems, such as the movement of parts
through a supply chain, the movement of vehicles in a transportation system, or
the movement of waste material around a mine. In addition to delaying material
flows, in some systems it is also important to delay information flows (e.g.,
an order is placed, but the order is not received for two days). Like
Reservoirs and Integrators, Material and Information Delays are conceptually
and mathematically distinct (materials are conserved, information is not), and
are therefore represented by two separate elements.
Two new input entry elements have been added: Material Input Histories and
Information Input Histories. These specialized look-up table elements are
designed to make input of large time histories (e.g., rainfall and other
historical records) very easy. You can enter data and identify what it
represents (e.g., a quantity, an instantaneous flow rate, a flow rate over next
time interval, discrete additions), and ask GoldSim to automatically convert
the data to a form that is appropriate for use in the model. For example, you
could enter a table of daily precipitation rates (i.e., a flow rate over a
specified interval), and GoldSim would correctly represent them as such,
regardless of the timestep used in the model.
A number of new elements to support discrete event simulation (Decision,
Milestone, Status, Triggered Event, Discrete Change Delay) have been added.
Coupled with a reworking of the mechanism for triggering elements (e.g, such as
Consequences, Conditional Containers, and Stochastics), these modifications
will be particularly useful for simulating decision logic and project
"Versioning" of a model file will be supported. Versioning allows you
to track changes to a model file over time, and is particularly useful for
large, complex models.
Note that the manuals will be significantly modified to reflect the changes in
this version, so if you were thinking about downloading and printing the
manuals, you may want to hold off until this version is released. In addition,
due to the large number of changes, some of which have the potential to affect
currently existing models (e.g., new integration algorithms), a short memo will
be produced to help users smoothly migrate to the new version.
GoldSim User Survey
Within the next week, we will be sending an electronic survey to each member of
the GoldSim User Community. The survey will include questions regarding your
general use of GoldSim and the support provided by the GoldSim Consulting
Group. Our hope is that the results of this survey will help us to better
understand the needs of our users. Each person that completes the survey will
be entered into a drawing to win a $100 gift certificate from Amazon.com.
Modeling Long-Term Health and Environmental Risk at the Nevada Test Site
Neptune and Company
Los Alamos, New Mexico USA
The Environmental Management office of the National Nuclear Security Agency at
the Nevada Test Site (NTS) manages low-level radioactive waste at facilities
near the town of Mercury, northwest of Las Vegas, Nevada. Management of these
facilities is entering a new phase following previously-conducted compliance
assessments. Post-compliance objectives fall under the domain of continued
maintenance and include closure, long-term monitoring and continuing disposal
operations. The new objectives require a complete probabilistic analysis of the
environmental system coupled with a model of cost and potential liabilities in
order to capture the impact of actions that might be taken to mitigate
long-term human health or environmental risks. Neptune and Company, an
environmental consulting firm, is currently implementing this fully coupled
environmental management system using GoldSim. One component of the management
system that is under construction is a fully probabilistic model of one type of
waste disposal configuration at the NTS, referred to as the Greater Confinement
Disposal boreholes. Some of these large diameter boreholes contain classified
transuranic waste buried below a depth of 21 m and backfilled with native
alluvium. The GoldSim model simulates the migration of contaminants from these
boreholes to the ground surface. The dominant contaminant transport processes
at this arid site are upward advection and biotic translocation.
If you want to determine if element A affects element B in a model that is very
complex, use the Affects list in combination with GoldSim's search feature.
Right-click on A and select Affects. When the browser appears, do a search for
B in the list. In version 7.3, a search bar will appear directly on the
browser. In previous versions, you can access the search by pressing Ctrl+F.
The GoldSim Model Library allows GoldSim users to build on the experience and
knowledge of others by sharing models. The Library is available from within the
GoldSim Members Area. If you have a model that you think would be worthwhile to
post to the library, please send it, along with text describing the model, to
You can search the Model Library by keyword and category
(e.g., Contaminant Transport, Financial, Water Resources).
We encourage you to visit the Library (and submit new
models). To keep you updated on additions to the Library, all new models added
to the Library will be summarized in the Newsletter each quarter.
The GoldSim Knowledge Base contains articles addressing frequently asked
questions, workarounds for known problems, and advice on applying GoldSim. The
Knowledge Base is available from within the GoldSim Members Area.
You can search the Knowledge Base by keyword and/or module.
We encourage you to visit the Knowledge Base, as even expert users are likely
to find useful information there. To keep you updated on additions to the
Knowledge Base, all new articles added to the Knowledge Base will be listed in
the Newsletter each quarter.
As most users are aware, we are constantly adding new features to GoldSim,
based on feedback from our own modelers, as well as those of our clients,
partners and customers.
In addition to the many minor improvements that we continuously make to the
software, we are currently working on two new GoldSim modules:
Replication Module. This module will represent our first step toward
integrating GoldSim with geographic information systems (GIS). Such a linkage
would enable a user to combine the spatial modeling tools of a GIS with the
dynamic modeling capabilities of GoldSim. In this first step, we will allow a
user to define template models (sub-models in containers) that GoldSim
automatically replicates across a user-specified grid. The template models will
be defined such that the replicated containers will be able to communicate
between grid cells (e.g., a model could reference an output from adjacent grid
Financial Module. This module will make simulating the financial aspects
of models (e.g., modeling a project or a company, evaluating investment and
financing decisions) much easier and more powerful. This first version of the
Financial Module will primarily consist of additional elements and features to
facilitate capital budgeting and cost accounting.
We hope to release both of these modules by the middle of 2002.
In addition, by early 2002, we expect to add an Index to all of the manuals, as
well as on-line Help and Tutorials.