Ergo Overview

Welcome

When Ergo is first launched, the welcome screen appears. From the welcome screen, users can select to read an overview of information about Ergo, follow built-in tutorials, or just begin working in Ergo (by selecting Workbench which will take you to the main Ergo screen, also known as the Workbench). See figure above.

Workbench Layout

The Ergo workbench consists of a number of Views, each containing information about a specific part of Ergo. Each view is like a sub-window within the Ergo workbench window, and can be minimized, maximized, moved, or even torn away from the main window into its own window. These interactions are done by clicking the minimize and maximize view icons in the view's title bar, or by clicking and dragging on the view's border or title bar.

See the image below for the most commonly used views in Ergo.

Scenario View

The Scenario View is where you will find a list of all the data for the scenario or scenarios that you are currently working with. Each scenario that you are working with is listed as a top-level item in this view, which can be expanded by clicking the plus (plus) icon next to its name, to see the details of the scenario. Inside each scenario, you can see a list of the Mappable Data and Scenario Data. All data listed in Mappable Data are the layers of data that appear in your rendered map whereas all the data listed in the Scenario Dataincludes all non-renderable data for the scenario (e.g. tables).

The Scenario View is also where you would go to do the major operations on your scenarios: adding an earthquake hazard or other data, running damage analyses, etc.

Visualization View

The Visualization Window Views are where the rendered maps of your scenario will appear. Each scenario can have its own rendered 2d and 3d map, so you can see the visualization multiple scenarios simultaneously if desired. It is here that you can get a quick visual overview of the results of your analyses. You can control the camera position by using the mouse, or click the view control buttons in the toolbar.

Data Catalog View

The Catalog View is a list of all the data that is available for you to use in your scenarios. It is organized first by repositories, which are stores of Ergo data. Repositories can represent local data, or data stored on a remote server. Within each repository, the data is organized by the type of data that it is. To add data to a scenario, you can navigate to and find the data within this view, then drag it into either the Visualization View for your scenario, or onto the scenario's name in the Scenario View. Before data can be made available to your scenario, it must be ingested into a repository and assigned a type. You can find instructions on ingesting building data here.

Style Editor View

The Style Editor is used to adjust the way in which a layer of data is displayed in the Visualization View. If the Style Editor is not visible, you can show it by right clicking a Mappable Data layer in the Scenario View, and selecting Change Layer Style. Once this view is showing, you can adjust the color, shape, opacity, and other display characteristics of the map layer. To apply your style changes, you must click the Apply button ( ) in the view's toolbar.

Other Views

Although these are some of the main views you will use, there are a few other views that are shown at various times while using Ergo and we'll discuss them below.

Table View

The Table View is used to display tabular data such as the attributes of a set of inventory data or analysis results. The most common way to see this view is by right-clicking a Mappable Data layer in the Scenarios View and selecting Show Attribute Table.

Reports View

By right-clicking on a scenario name in the Scenarios View, and selecting Reports..., you can access the Select Report View. By default there are two report types available for every result based on the metadata for each result type, the Default Summary Report and Default Detail Report. The summary report will provide a summary of results and the detail report will provide explicit detail about each result (e.g. building by building results). To run a report, select the report you wish to run, right-click on it and select the Run Report option. The selected report will be generated and displayed. From that point, you can choose to print or save the report.

Fragility View

If you right-click a fragility dataset from the Catalog View, you can select View Fragility to access the Fragility View. The Fragility View shows a list of fragility types that you can drill down into to select and view a particular fragility curve. When you have found the fragility curve that you want to view, right-click it and select View Fragility Set to view a graph of the fragility curve. See the image below.

Ergo Tutorial

Example Scenario

In this demonstration, we will use Ergo as a specific stakeholder would use the tool. Consider the stakeholder to be an Emergency Manager who wishes to determine possible impacts of earthquake hazards on Shelby County Tennessee buildings. The Emergency Manager wishes to investigate the impact of a specific speculated earthquake on the existing building stock in Memphis and Shelby County Tennessee. Consider this analysis to be preliminary, and therefore limit the scope of the study by neglecting single family residences. For this analysis we will use a fictitious moment magnitude 7.7 event located at Marked Tree Arkansas.

In the process, we will see how the Emergency Manager will launch the Ergo application, load the GIS data for Shelby County, and then generate earthquake hazard information based on the scenario he wants to investigate. After he has loaded this base information, he can interactively choose and display information for the specific items he wants to evaluate - the buildings, as well as load fragility information for these particular structures. From there, we will witness an analysis of the impact of the hazard. These factors have important social and economic impacts which can be investigated with more advanced analyses that Ergo has available.

Creating a New Scenario

Viewing the Scenario and Adding Data

At this point, your scenario has been created. You will see your scenario listed in the Scenario View and a blank outline of Shelby County has appeared in the Visualization View. See figure below.

Next, we will learn how to add data to our scenario, and how to manipulate the Visualization View.

First, we will add elevation data to the scenario. In the Catalog view (the lower-left view of your workbench is arranged in the default setting, as shown in the figure below), expand the Ergo Demo Data item, then Topography and finally Digital Elevation Model. Click and drag the Shelby County Topography item into the Visualization View.

At this point, an elevation map should have been added to the Visualization View. We will also add building information to the Scenario. Under the Catalog View, still under the Ergo Demo Data item, expand Buildings, then Building Inventory v5.0, then Shelby County No SF Buildings v5. Drag the dataset for Shelby County No SF Buildings v5, which excludes single family homes, into the Visualization View as well. Alternatively, you can right-click the item and select Load Dataset.
At this point, your Visualization View should look similar to the image below:

To make the buildings easier to see, we will adjust their map style. From the Scenario View, expand Shelby County, then Mappable Data. You should see the list of the data that you added to the Scenario. Right click on Shelby County No SF Buildings v5, and choose Change Layer Style.

In the Style Editor (see figure below), the Simple Style tab should be active. Click the black box labeled Color, and select a color that is easier to see, such as yellow. Click Ok in the color selection box and then to apply the style change, click the Apply Style button in the Style Editor's tab bar. ( )

Some visualization controls:

  1. To zoom/pan/etc, use the controls at the top of the Visualization View. Use these to adjust your view.
  2. To view a 3d rendered view of the same information, right click the entry for your Scenario, and choose Render in 3D (VTK). This will bring up a second Visualization View that shows the same map, but from a 3d rendered perspective.
  3. After adjusting your view, if you want to restore to the original default view in the Visualization, click the Zoom to full extent button in the toolbar ( )

Running an Analysis

Now that we have a basic map to look at, we will learn how to run an analysis. Analyses in Ergo consist of any sort of calculation that generates data. For example, generating a deterministic earthquake map based on a magnitude and epicenter would be considered one type of analysis. Using that earthquake map as well as building inventory data to generate information about building damage would be another type of analysis.

In this example, we want to find building damage results based on a deterministic earthquake hazard that we will specify.

Decision Support

In this section we are going to illustrate how to run the Building Decision Support analyses in Ergo. The analyses include the Building Decision Support Attributes Analysis, theEquivalent Cost Analysis(ECA), the Multi-Attribute Utility Analysis(MAUT) and the Individual Utility Analysis. The Building Decision Support analysis computes the decision attributes such as monetary loss, injuries, deaths and function loss that can be used by the Equivalent Cost Analysis to turn the non monetary attributes into monetary attributes for making decisions. Alternatively, these attributes can be given to the Multi-Attribute Utility Analysis to compute the overall utility of the results. The Individual Utility Analysisprovides the change in utility for retrofitting a single structure while leaving all other structures unchanged. This is useful for determining which building(s) give the best return for your investment.

Before going through the decision support process, there are a few things the user will need to get the most out of these analyses. For the equivalent cost analysis, the user will need conversion values for the non-monetary variables such as injuries, deaths and days of function loss or use the pre-defined values in Ergo. For the multi attribute utility analysis and the individual utility analysis, the user will need to define utility curves for each attribute as well as determine what the weight of each attribute is in the overall utility. Example curves are available, but will not provide good results because they are not defined to work with the dataset we have and were meant only for illustration purposes.

Decision Attributes

Let's use the building dataset we already have loaded to generate some decision attributes that we can then use in the ECA and MAUT analysis. We can choose to either use the damage datasets we have already generated or generate some new datasets. For now, we'll use what we already have since we will need to obtain the as-built decision attributes to find the incremental change in utility for upgrading structures one at a time.

Equivalent Cost Analysis

Now that we have the as-built decision attributes, let's run the Equivalent Cost Analysis to assign the decision variables dollar values so we have a common unit that can be added to obtain total loss.

One useful visualization for these results is running a statistical analysis on the results. Do the following to bring up the statistics view.

Multi-Attribute Utility Analysis

Perhaps more informative than the Equivalent Cost Analysis is the Multi-Attribute Utility Analysis (MAUT). Instead of converting the non-monetary decision variables to monetary values as the common unit for addition, we convert the decision variables to utility values. Each decision variable is given a weight so that the overall utility adds to at most, 1.0. This can be very useful since assigning value to life can be difficult and can better be measured by acceptable and unacceptable consequences. The user also has more control over how each variable weighs into the overall utility. For example, maybe injury and death prevention are most important and monetary cost is least important. The decision maker can give more weight to the death/injury utilities so that if deaths and injuries are minimized, a higher utility value will be obtained thus allowing us to better judge the retrofit strategy.

This also makes it more clear why a decision maker must define their own utility curves. Every decision maker will have a different view on what are acceptable and unacceptable consequences. It is important for decision makers to define utility curves that describe their risk attitude so that the decision support tools can provide the best possible guidance. That being said, below we will outline how to use the sample utility functions that will illustrate how MAUT works.

Individual Utility Analysis

The last analysis for decision support that we want to illustrate is the Individual Utility Analysis. We already have the as-built damage so all we need to do is generate another damage dataset with building upgrades and its associated Building Decision Support Attributes dataset.

After the analysis finishes, you will have 5 additional columns. The utility column has the as-built utility value for the non-retrofit scheme. Following that are 3 columns, util_low,util_mod and util_high, which gives the change in utility if the building is upgraded to low code, to moderate code and to high code. The last column lists the best alternative based on the 3 utility values. For this to be useful we would have needed to do decision support attributes for moderate code and high code. You should see an attribute table similar to the one below if you used the settings we did

Analyzing Results

Now that the analyses that we were interested in have been completed, it's time to analyze and try to make sense of the results we obtained earlier. The lessons here will also help you with understanding the decision support results if you followed that part of the tutorial.

There are various ways of viewing and visualizing the results, which we will learn now.

Table View Results

3D Damage Bars

Aggregating Data

Filtering Results

Reporting

The last visualization we want to take a look at is generating reports for each dataset in Ergo. This operation is supported by the metadata that is specified for each dataset and result type so that Ergo can generate basic reports that contain the information that is important to the user without any customization required. For those users who have more specific needs, the reports can be customized. Metadata is defined for each result type that specify important result data including what should be graphed, what type of aggregation should be used to summarize the data, etc. In the next steps, we will demonstrate how a user will generate a report for the building damage.

Conclusion

Based on this simple building damage analysis, we can conclude that the Ergo tool helps to identify areas of high risk. Using the decision support tools for buildings in Ergo, we looked at some mitigation options that may be beneficial to consider. The only additional requirement would be that the decision maker define their risk tolerance in utility functions for Ergo to use in order to recommend mitigation options. From the analyses performed, the Emergency Manager in our example is able to take the information and results from this analysis and evaluate detailed options for specific buildings base on proprietary information in the department's databases and files. Furthermore, probabilistic scenarios can also be evaluated in addition to a deterministic earthquake such as the one we used in this example. The analysis could also be expanded to look at other components in the region such as the utility networks, schools (since these typically serve as temporary shelters), hospitals, police stations, etc. Some of these data are available with the default installation of Ergo and is left as an exercise to the user.

The Ergo tool provides an environment for visual exploration, analysis and evaluation of engineering options pertinent to investigating bridge and building retrofit options. These results for bridges and buildings can be fed into the traffic models and the decision support models to aid in selecting retrofit options, emergency routing, and pre/post mitigation planning. Furthermore, the Ergo Cyberenvironment enables Ergo users to more effectively collaborate and share results.

Please contact the Mid-America Earthquake Center for further information on Ergo.

Mid-America Earthquake Center
205 N. Mathews Avenue
1240 Newmark Lab
Urbana, IL 61801
Tel: (217) 244-6302 Fax: (217) 333-3821