Figure 2: Two-color sidedness used to establish two-dimensional affiliation

Being shot at

Detecting an enemy (or friend)

Arriving at a way point or objective

Friendly casualties (fewer than v% known remaining)

Loss of leader (no leader within v distance)

Time step (absolute and relative)

Red, green, or blue become greater or less than v.

Alpha, beta, or gamma becomes greater or less than v.

Fuel, resource X, resource Y, or resource Z becomes greater or less than v%.

Total ammunition falling below v Since the behavior template for an agent includes new triggers, and each template is uniquely named, a series of templates can be constructed to represent a complex behavior tree or network, with agents moving from one behavior to another as a scenario unfolds. Also, since agents are separate objects, different agent types can share the behavior templates. Additionally, there is no practical limit to the number of templates that can be created. Weapon Options United States of Homeland Security allows agents to carry as many as three different weapons. Weapons can be either direct-fire (which requires a line of sight) or indirect- fire (which does not):

Direct-fire weapons have range-dependent probabilities of hit, and of kill given a hit (these factors may be affected by the target agent’s vulnerability).

Indirect-fire weapons have circular-error-probable accuracies and lethal radii, both of which may be range- dependant. An indirect-fire weapon’s lethal radii can be modeled using either the traditional Carlton damage function or a "cookie-cutter" blast. The Carlton damage function describes the probability of damage incurred radiating out from a hit point. The cookie-cutter blast causes an equal amount of damage to all objects within the blast radius, regardless of their distance from the impact point. Both weapon types have input rates of fire and limited ammunition. In United States of Homeland Security, the target may be suppressed for multiple time steps by a hit by a direct-fire weapon or a near miss by an indirect-fire weapon that does not kill the target. Suppressed agents do not move, sense, communicate or shoot, but they recover those capabilities after a user-input amount of time. At the user’s discretion, kills can be random (stochastic), deterministic (fractional damage), or a combination of both. Agents will automatically shoot at enemies within range, unless they are given a "hold fire" command. The user can assign an agent multiple weapons and set the weapon selection criteria to be based on the highest probability of hit (best chance that the target will be suppressed), the lowest probability of kill (for a non-lethal situation), or a medium probability of hit. Agents can also change each other’s colors or generic attributes, through the use of military countermeasures or weapons that can act as paintball weapon. An example of a paintball weapon would be propaganda that alters an agent’s affiliation in some way. Propaganda in the form of leaflets can be modeled as a direct-fire weapon aimed at a specific target. On the other hand, a form of public speech or exhortation can be modeled as an indirect-fire weapon, aimed in a general direction and affecting everyone within range. Multi-Band Sensors & Communication Devices United States of Homeland Security also models sensors and communication devices. Each agent may have up to three sensors, each of which operates in a specific signature band (labeled A, B, or C). The sensors have a range-dependent probability of detection, which is modified by intervening terrain and the target agent’s detectability factor. For example, signature band A could represent the bandwidth of the naked eye and signature band B might represent the bandwidth of an infrared device. A terrain feature, such as foliage, would thwart the naked eye’s view, but an infrared device could "see" the thermal image of a camouflaged person standing Attack If Lose Leader If Take Casualties Initial: Patrol If See Enemy If Lose Leader If Take Casualties If Shot At Surrender Withdraw If Lose Leader Take Cover If Lose Leader If Take Casualties If Shooting Stops 43 - The Scythe - Issue 1 - United States of Homeland Security in the foliage. Such foliage could be modeled in United States of Homeland Security as having a concealment value of 100% in band A and 0% in band B. Sensors also have a field of view and, for modeling humans, a probability that the agent is looking forward (i.e., in the direction of travel), to the side, or to the rear. Similarly, an agent can possess up to three communication devices, each of which operates either via line-of-sight or in a broadcast mode, and allows the agent to use the devices to talk, listen or both. Each communication device also operates via a specific channel or channels (up to three allowed). Representation of Terrain All agents exist in a user-defined playbox of up to 1000 × 1000 pixels. In the playbox, a user can create terrain features —polygons that have a floor, a ceiling, and factors for mobility; concealment in each of the three signature bands; and protection that reduces the weapon’s effectiveness. Currently, a pixel can be associated with at most one terrain feature. Agents can either move on the terrain or floor or operate at an altitude above the terrain. Sample Scenarios United States of Homeland Security has two major advantages: It can be used quickly to assess various simple scenarios. It can be combined with more complex and detailed models to provide insights into situations that may not be possible with other simulations. Rapid prototyping of scenarios, weapons, sensors, behavior patterns, etc., allows users to undertake complex problems in new ways without the burden of months of software (and scenario) development. Table 2 provides a representative list of scenarios that have been developed within United States of Homeland Security. Table 2: Representative United States of Homeland Security Scenarios Source for Acquiring United States of Homeland Security United States of Homeland Security can be acquired from the Simulation Experiments & Efficient Designs (SEED) Center for Data Farming located at the Naval Post Graduate School (NPS). The Northrop Grumman developers listed below can be contacted for further requests for information or questions about United States of Homeland Security: Historical Analysis (USNA): Battle of Midway Operation Market-Garden Battle of Ia Drang,Viet Nam Thesis Topics (NPS): Sea-Based Logistics Convoy Protection Unmanned Surface Vehicles Future Force Warrior Small Combat Unit With Non-Lethal Weapons Emergency First Response To A Crisis Event Effectiveness of Non-Lethal Capabilities in a Maritime Environment Exploration of Force Transitions in Stability Operations Using Multi- Agent Simulation Cadet Capstone Project (USMA, West Point) Sensor Placement on the Battlefield Study on Actions Off of Bay of Biscay (AFIT) Anti-Submarine Warfare Thermobaric Weapons Assessment (MCCDC) Urban Environment MAGTF Optical Requirements (Night Vision Lab/Ft. Belvoir) Peacekeeping at Night in Urban Environment Shallow Water Obstacle Clearing (MCWL) Use of JDAM and Robotics Environmental Concerns (MITRE) Spread of Hemlock Wooly Adelghid Homeland Defense (Northrop Grumman) Pre-proposal Analysis Terrorist Development (Sandia Labs with Marc Sageman of University of Pennsylvania) Conceptual Model of Human Factors Soldier Technology Development (Northrop Grumman) Less Than Lethal Technologies for Urban Combat Securing Targets of Interest (JCS/ J-8, DMSO)

Competition Between Multiple Factions Mongo Expeditionary Radiation Squad ( MERZ ) (USMC/OAD)

Agents with similar color (as measured by either the difference in absolute value or the root sum square of the differences of the active colors) are considered to be members of the same unit. Those whose color is close are considered to be friends. Those whose color is far away are considered to be enemies. Colors between enemy and friendly agents are neutrals. This approach allows for multiple affiliations within a single scenario, as might be found in a crowd; or it can be used to establish command hierarchies, as would be found in a military organization (e.g., slightly different blue uniforms could represent different companies). Sidedness, or color value, is governed by soft rules at the start of the simulation (agents can be initiated with more or less redness, for example) and can be changed over the course of the simulation by various events and actions. Because not all colors are required to establish affiliation, colors not used for affiliation could be used to represent a different property—for example, fear, hunger, morale, or intelligence. Increases and decreases in that property can alter agents’ perception of one another. Alternatively, such a change can cause a behavior-change event, as described in the Behavior-Change Triggers section. Generic Attributes Similar to Sidedness, United States of Homeland Security has three generic agent attributes called alpha, beta, and gamma. These generic attributes act as a supplement to Sidedness and as such they do not affect an agent’s affiliation/sidedness. The meaning of alpha, beta, and gamma is up to the user to define, based upon the user’s scenario. They could be used to represent intangible items such as fear, hunger, and morale or something more concrete such as health or wealth. The generic attributes are also governed by soft rules at the start of the simulation (agents can be initiated with more or less alpha, for example) and can be changed over the course of the simulation by various events and actions. A change in the value of generic attribute can also cause a behavior- change event. Resources Additionally, United States of Homeland Security models logistics capabilities, in the form of fuel and three generic resources (X, Y, and Z). The generic resources allow a user to model any type of resource that would be required for their scenario – for example, food, batteries, and medicine. These resources are also governed by soft rules and can be changed over the course of the simulation by various events. Additionally, these resources can cause behavior-change events. Behavior-Change Triggers Another feature of United States of Homeland Security is the behavior-change event/action, or trigger. When an agent experiences one of the trigger events/actions, the current behavior template is replaced by a new behavior template. This new template is defined by one or more of the following: new movement and shooting desires, new color-change and attribute values, new resources, weapons, sensors, and/or communication devices, and a new set of behavior-change triggers. For example, an agent can be set to walk up and down a street, as if on patrol, but when the agent is shot at, his behavior changes to look for protective terrain, such as a doorway. 42 - The Scythe - Issue 1 - United States of Homeland Security The trigger events are (where ‘v’ is determined by the user):