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Air Force Institute of Technology

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Articles 3721 - 3750 of 5699

Full-Text Articles in Engineering

Swarming Reconnaissance Using Unmanned Aerial Vehicles In A Parallel Discrete Event Simulation, Joshua J. Corner Mar 2004

Swarming Reconnaissance Using Unmanned Aerial Vehicles In A Parallel Discrete Event Simulation, Joshua J. Corner

Theses and Dissertations

Current military affairs indicate that future military warfare requires safer, more accurate, and more fault-tolerant weapons systems. Unmanned Aerial Vehicles (UAV) are one answer to this military requirement. Technology in the UAV arena is moving toward smaller and more capable systems and is becoming available at a fraction of the cost. Exploiting the advances in these miniaturized flying vehicles is the aim of this research. How are the UAVs employed for the future military? The concept of operations for a micro-UAV system is adopted from nature from the appearance of flocking birds, movement of a school of fish, and swarming …

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Prepositioned Trailers For Aircraft Battle Damage Support, Scott M. Murray Mar 2004

Prepositioned Trailers For Aircraft Battle Damage Support, Scott M. Murray

Theses and Dissertations

Air superiority is essential in today's wartime environment. Aircraft that are damaged and not returned to combat can have a considerable impact on the quest for dominance in the air. To maintain operational effectiveness, an organization must have the capability to quickly repair damaged aircraft. The purpose of an Aircraft Battle Damage Repair (ABDR) program is to rapidly and effectively repair damaged aircraft to fly additional operational sorties and further contribute to wartime objectives. This capability must consist of providing the necessary tools and equipment for the rapid repair of aircraft. When an ABDR team deploys in support of an …

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A Demand Side Requirements Model To Forecast C-17 Mobility Aircraft Availability, Joseph R. Huscroft Jr. Mar 2004

A Demand Side Requirements Model To Forecast C-17 Mobility Aircraft Availability, Joseph R. Huscroft Jr.

Theses and Dissertations

Current aircraft forecasting methods of the Air Mobility Command (AMC) Directorate of Logistics are reliant on the experience of personnel and lead to after the fact, labor-intensive analysis. These deficiencies led AMC to the development of a Mobility Aircraft Availability Forecasting (MAAF) model. The purpose of the MAAF model is threefold: predict aircraft availability in order to provide the Tanker Airlift Control Center (TACC) with a forecast of aircraft that will be available for AMC mission requirements, provide what if capabilities that analyze the effects of tasking and policy changes, and to provide foresight into problems associated with aircraft availability …

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Theoretical Models For Aircraft Availability: Classical Approach To Identification Of Trends, Seasonality, And System Constraints In The Development Of Realized Models, David B. Wall Mar 2004

Theoretical Models For Aircraft Availability: Classical Approach To Identification Of Trends, Seasonality, And System Constraints In The Development Of Realized Models, David B. Wall

Theses and Dissertations

This research provides forecasting models that will enable the AMC Directorate of Logistics analysis section to predict aircraft availability and provide the TACC with a monthly forecast of the number of aircraft that will be available to fulfill AMC mission requirements.

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Effect Of Dimple Pattern On The Suppression Of Boundary Layer Separation On A Low Pressure Turbine Blade, John P. Casey Mar 2004

Effect Of Dimple Pattern On The Suppression Of Boundary Layer Separation On A Low Pressure Turbine Blade, John P. Casey

Theses and Dissertations

Three dimple patterns were investigated to ascertain their relative effectiveness on controlling boundary layer separation from a low-pressure turbine blade. The three cases included a single row of dimples at 65% of the axial chord with 2.22 cm spacing, a single row of dimples at 65% of the axial chord with 4.44 cm spacing, and a two-row staggered pattern with rows at 65% and 76% of the axial chord with 4.44 cm spacing. The multiple row case was such that the center of the upstream dimple set at the midpoint between two downstream dimples. The dimple spacing was measured center-on-center. …

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Improving The Estimation Of Military Worth Of The Advanced Tactical Laser Through Simulation Aggregation, Michael T. Cook Mar 2004

Improving The Estimation Of Military Worth Of The Advanced Tactical Laser Through Simulation Aggregation, Michael T. Cook

Theses and Dissertations

Fielding High Energy Laser (HEL) weapon systems presents technological challenges as well as employment and financial challenges. The risk associated with the challenges mandates the development process include computer simulation models capable of predicting weapon system performance from the engineering level to assessing the military worth of employing HEL systems in combat scenarios. This research effort focuses on developing laser performance data at a higher fidelity engagement model and integrating the performance data into a mission level model. The propagation of the laser from the transmitting aperture to the target is modeled at the engagement level through the employment of …

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Value-Focused Thinking In The Presence Of Weight Ambiguity: A Solution Technique Using Monte Carlo Simulation, Timothy W. Porter Mar 2004

Value-Focused Thinking In The Presence Of Weight Ambiguity: A Solution Technique Using Monte Carlo Simulation, Timothy W. Porter

Theses and Dissertations

When a Decision Maker is asked to provide his or her preferences, the response represents a snapshot in time. While their preference structure elicited at any given moment may represent their revealed preferences at that point in time, it may change over time. These changing preferences over time represent ambiguity in the decision maker's preferences. Other sources of ambiguity may exist. One weakness of many decision analysis techniques today is the inability to incorporate ambiguity into the basic decision model. The existence of the problem has been known and commented on for many years. This research addresses that problem. It …

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An Investigation Of The Optimal Sensor Ensemble For Sensor Fusion, Paul P. Clemans Mar 2004

An Investigation Of The Optimal Sensor Ensemble For Sensor Fusion, Paul P. Clemans

Theses and Dissertations

This thesis continues the research begun by Storm, Bauer and Oxley in 2003 into the fusion of classifiers. It examines the fusion of up to three correlated classifiers using three different fusion techniques. The overall objective was to determine the optimal ensemble of classifiers to maximize the expected classification accuracy. The ISOC fusion method (Haspert, 2000), the ROC Within fusion method (Oxley and Bauer, 2002) and a Probabilistic Neural Network were the three fusion techniques employed in these set of experiments. Performance of the classifiers and the fusion methods is measured via ROC curves. Two possible configurations of feature correlations …

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Modeling And Simulation Of The Military Intelligence Process, Carl R. Pawling Mar 2004

Modeling And Simulation Of The Military Intelligence Process, Carl R. Pawling

Theses and Dissertations

There is concern within U.S. space and intelligence organizations that the current Tasking, Processing, Exploitation, and Dissemination processes may be insufficient to support current and future Intelligence, Surveillance, and Reconnaissance systems. As part of a larger intelligence process, more detailed analysis becomes critical to determine what portions need to be improved. This analysis can be accomplished by simulation, which is appropriate due to the complexity of the process and the ability to compare variations in the process. We construct a high level model of a generalized military intelligence process based in part on the Intelligence Cycle outlined in Joint Publications. …

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Atmospheric Simulation Using A Liquid Crystal Wavefront Controlling Device, Matthew R. Brooks Mar 2004

Atmospheric Simulation Using A Liquid Crystal Wavefront Controlling Device, Matthew R. Brooks

Theses and Dissertations

Test and evaluation of laser warning devices is important due to the increased use of laser devices in aerial applications. In this thesis, an atmospheric aberrating system is developed to enable in-lab testing of laser warning devices. This system employs laser light at 632.8nm from a Helium-Neon source and a spatial light modulator (SLM) to cause phase changes using a birefringent liquid crystal material. Before the system can be used, the SLM phase response must be quantified to ensure proper manipulation of index of refraction. Additionally, diffraction from the SLM and real-world system scaling are addressed. Once completed, the atmospheric …

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Target Recognition Using Linear Classification Of High Range Resolution Radar Profiles, Ricardo A. Diaz Mar 2004

Target Recognition Using Linear Classification Of High Range Resolution Radar Profiles, Ricardo A. Diaz

Theses and Dissertations

High Range Resolution (HRR) radar profiles map three-dimensional target characteristics onto one-dimensional signals that represent reflected radar intensity along target extent. In this thesis, second through fourth statistical moments are extracted from HRR profiles and input to Fisher Linear Discriminant (FLD) classifiers. An iterative classification process is applied that gradually minimizes required a priori knowledge about the target data. It is found that the second through fourth statistical moments of HRR profiles are useful features in the FLD classification of dissimilar targets and they provide reasonable discrimination of similar targets. Greater than 69% correct classification for two-target scenarios and greater …

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Reconstruction Algorithm Characterization And Performance Monitoring In Limited-Angle Chromotography, Kevin C. Gustke Mar 2004

Reconstruction Algorithm Characterization And Performance Monitoring In Limited-Angle Chromotography, Kevin C. Gustke

Theses and Dissertations

Hyperspectral data collection and analysis is an increasing priority with the growing need to obtain greater classification precision than offered by traditional spatial imagery. In this thesis, trends in hyperspectral chromotomographic reconstruction are explored where reconstruction is performed using a series of spatial-chromatic images. Chromotomography involves capturing a series of two-dimensional images where each image is created by placing a prism in front of the focal plane array; causing spectral dispersion corresponding to a series of prism angles over a single rotation. Before testing reconstruction, synthetic data is produced, approximating what would be produced from prism dispersion on the focal …

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Microprocessor-Based Systems Control For The Rigidized Inflatable Get-Away-Special Experiment, David C. Moody Mar 2004

Microprocessor-Based Systems Control For The Rigidized Inflatable Get-Away-Special Experiment, David C. Moody

Theses and Dissertations

As the demand for space based communications and faster data throughput increase, satellites are becoming larger. Larger satellite antennas help to provide the needed gain to increase communications in space. Compounding the performance and size trade-offs are the payload weight and size limit imposed by the launch vehicles. Inflatable structures offer a cost saving opportunity since the structure is significantly lighter and has a reduced storage volume. This allows for smaller launch vehicles and for increased performance capabilities. Inflatable structures offer possibilities for increased satellite lifetimes, increased communications capacity, and reduce launch costs. This thesis develops and implements the computer …

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Magnetogasdynamic Flow Control Of A Mach Reflection, Brian E. Earp Mar 2004

Magnetogasdynamic Flow Control Of A Mach Reflection, Brian E. Earp

Theses and Dissertations

Two-dimensional regular and Mach reflections have been studied in the Mach 4.96 dual-solution domain for a 25° and 26° double-fin inlet. The steady-state computational Mach and regular reflections were subjected to magnetogasdynamic forces to determine whether these forces could be used as a possible flow control mechanism. The numerical code employed for this research solved the inviscid Euler equations with added source terms for the ponderomotive force and accompanying energy interactions. The 25° regular reflection was determined to be extremely sensitive to a decelerating Lorentz force. Transient application of the force led to the transition of the regular reflection to …

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Characterization Of The Target-Mount Interaction In Radar Cross Section Measurement Calibrations, Donald W. Powers Mar 2004

Characterization Of The Target-Mount Interaction In Radar Cross Section Measurement Calibrations, Donald W. Powers

Theses and Dissertations

Radar Cross Section (RCS) measurements are quintessential in understanding target scattering phenomenon. The reduced RCS of modern weapons systems stresses the capability of current RCS measurement ranges. A limiting factor that has recently become more significant is the electromagnetic coupling between a test target and the mounting hardware used to support it and control its orientation during the RCS measurement. Equally important is the electromagnetic coupling between the RCS calibration artifact and its mount, which provides an opportunity to explore the coupling phenomena without delving into operationally sensitive areas. The primary research goal was to characterize the interaction between a …

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Demonstrating Optothermal Actuators For An Autonomous Mems Microrobot, Francis R. Szabo Mar 2004

Demonstrating Optothermal Actuators For An Autonomous Mems Microrobot, Francis R. Szabo

Theses and Dissertations

There are numerous applications for microrobots which are beneficial to the Air Force. However, the microrobotics field is still in its infancy, and will require extensive basic research before these applications can be fielded. The biggest hurdle to be solved, in order to create autonomous microrobots, is generating power for their actuator engines. Most present actuators require orders of magnitude more power than is presently available from micropower sources. To enable smaller microrobots, this research proposed a simplified power concept that eliminates the need for on-board power supplies and control circuitry by using actuators powered wirelessly from the environment. This …

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Using Value-Focused Thinking To Evaluate The Effectiveness Of Air Force Utility Privatization, Carlos Braziel Mar 2004

Using Value-Focused Thinking To Evaluate The Effectiveness Of Air Force Utility Privatization, Carlos Braziel

Theses and Dissertations

The majority of the Air Force s stateside utility systems are old, obsolete, and unreliable. The cost to upgrade and repair these systems is currently estimated at over $4 billion. In response, the Air Force began efforts to convey ownership of these utility systems to the private sector through privatization efforts. However, privatization critics believe that newly privatized entities of government will cost the public more money and provide a lower level of service. Therefore, independent audits are a necessity to ensure government initiatives, meet their intended goals. However, the Air Force currently lacks an effective auditing tool to ensure …

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Characterization Of Microbial Processes That Degrade Chlorinated Solvents In A Constructed Wetland Using Organic Acid And Inorganic Anion Concentration Profiles, Chad B. Bondurant Mar 2004

Characterization Of Microbial Processes That Degrade Chlorinated Solvents In A Constructed Wetland Using Organic Acid And Inorganic Anion Concentration Profiles, Chad B. Bondurant

Theses and Dissertations

Chlorinated solvents have been used in industrial cleaning and degreasing processes in the United States since the early 1900s, and their induction into the environment increased significantly with the growth of industrial processes over the past century. PCE, TCE and their daughter products have been associated with a number of human health concerns and are currently the most common contaminants found in groundwater in the United States. Wetlands possess characteristics necessary for the complete degradation of chlorinated ethenes by microorganisms via anaerobic and aerobic regions that foster the necessary oxidation-reduction conditions. Organic acid and inorganic anion concentrations were evaluated in …

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Developing Team Cohesion: A Quasi-Field Experiment, John F. Costello Mar 2004

Developing Team Cohesion: A Quasi-Field Experiment, John F. Costello

Theses and Dissertations

Within military organizations, research findings have lent support to the positive influence cohesion has on group performance in combat and non-combat areas, Beyond performance, research findings show that cohesion influences the job satisfaction, and health of military members, particularly under highly stressful conditions, such as those encountered in combat or extended deployments. The purpose of this research effort is to further analyze the strategies that should be used to develop cohesiveness among Air Force members. This was done by testing the extent to which cohesion changed when familiarization and challenging situations were coupled in a technical training course geared towards …

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Recovering From A Stalled Change Initiative: A Case Of Correcting Implementation Mistakes, Ellen L. Dorey Mar 2004

Recovering From A Stalled Change Initiative: A Case Of Correcting Implementation Mistakes, Ellen L. Dorey

Theses and Dissertations

Amid an age of increasing technology, innovation, and global business competition, there is no question that the pace organizational changes are introduced will increase, as well. With this pace of change, organizational leaders might find themselves short on the time and resources necessary to properly create readiness by utilizing implementation strategies. Frequently, a change initiative that is not introduced properly will meet resistance within the organization. When strong resistance is encountered, the initiative is often abandoned and replaced with some other effort. However, in some situations, the initiative can not be abandoned and implementation must continue. This research effort sought …

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A Study Of Information Exchange Between United States Air Force Bases And Their Surrounding Communities, Andrew C. Clewett Mar 2004

A Study Of Information Exchange Between United States Air Force Bases And Their Surrounding Communities, Andrew C. Clewett

Theses and Dissertations

Data, information, and knowledge are exchanged daily from United States Air Force (USAF) bases to surrounding communities. The purpose of this research is to aid managers and commanders in gaining a better understanding of their information flow and bettering their information management practices. The research specifically seeks answers to the questions of where information is exchanged, why information is exchanged, and to whom information is exchanged with.

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The Application Of Value Focused Thinking To Utilities Privatization Source Selection, J. Heath Duncan Mar 2004

The Application Of Value Focused Thinking To Utilities Privatization Source Selection, J. Heath Duncan

Theses and Dissertations

The Department of Defense's utility systems have suffered from under-funding and lack of technology investment, thereby creating a service gap between these DoD systems and systems operated by commercial providers. In order to overcome this gap and refurbish their systems, the DoD has focused its efforts on privatization of these systems. The utilities privatization decision is extremely vital and permanent and thus warrants backup source selection methodologies. Since awarding contracts in the utilities privatization arena requires a decision considering tradeoffs between multiple competing objectives, a value-focused thinking approach was used to create a structured, standardized value model taking into account …

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Policy Analysis Of Chapter 101a, Readiness And Range Preservation, Of The National Defense Authorization Act For Fiscal Year 2004, William E. Sitzabee Mar 2004

Policy Analysis Of Chapter 101a, Readiness And Range Preservation, Of The National Defense Authorization Act For Fiscal Year 2004, William E. Sitzabee

Theses and Dissertations

This research analyzed the United States Air Force's ability to meet the two conditions required for exemptions of critical habitat designations that are authorized under the National Defense Authorization Act for Fiscal Year 2004. The research was limited to natural resources management on United States Air Force training ranges. Department of Defense exemptions can only be achieved if two conditions exist: the management activities must meet the intent of the Endangered Species Act and conserve the threatened and endangered species identified on the lands managed under an Integrated Natural Resources Management Plan (INRMP), and the plan must ensure that there …

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Application Of Horizontal Flow Treatment Wells For In Situ Treatment Of Mtbe-Contaminated Groundwater, Preston F. Rufe Mar 2004

Application Of Horizontal Flow Treatment Wells For In Situ Treatment Of Mtbe-Contaminated Groundwater, Preston F. Rufe

Theses and Dissertations

This study utilized a three-dimensional numerical model to evaluate the potential application of HFTWs to manage MTBE-contaminated groundwater. HFTWs consist of two dual-screened treatment wells. One well operates in an upflow mode, with MTBE-contaminated water extracted from an aquifer through a screen in the deep portion of an aquifer and injected into the aquifer through a shallow well screen, while the adjacent well operates in a downflow mode, extracting water from the shallow zone of the aquifer and injecting it into the deep zone. As the MTBE-contaminated water flows through the wells, an electron acceptor and/or another electron donor is …

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Performance Study Of Two-Stage-To-Orbit Reusable Launch Vehicle Propulsion Alternatives, Marc A. Brock Mar 2004

Performance Study Of Two-Stage-To-Orbit Reusable Launch Vehicle Propulsion Alternatives, Marc A. Brock

Theses and Dissertations

This study investigated the performance of five Two-Stage-To-Orbit reusable launch vehicles (RLV), with stages propelled by rocket engines, turbojet engines and Rocket Based Combined Cycle (RBCC) engines. Horizontal versus vertical takeoff launch and direct versus lifting ascent trajectories were also studied. A method was conceived using a 3 degree of freedom optimization program, stage inert mass fractions, and a fixed gross takeoff weight (GTOW) of 1,000,000 lbf to determine each RLVs performance based on payload weight delivered to orbit and total vehicle inert weight. RLV trajectory constraints, mass fractions, engine performance, and aerodynamics were assumed from literature of similar RLVs …

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Infrared Methods For Daylight Acquisition Of Leo Satellites, Joel E. Nelson Mar 2004

Infrared Methods For Daylight Acquisition Of Leo Satellites, Joel E. Nelson

Theses and Dissertations

Raven is an award-winning optical system design paradigm that couples commercially available hardware and software along with custom data analysis and control software to produce low-cost, autonomous, and very capable space surveillance systems. The first product of the Raven program was a family of telescopes capable of generating world-class optical observation data of deep-space satellites. The key to this system was the use of astrometric techniques for position and brightness data. Astrometry compares a satellite to the star background within the sensor field of view; since the position and brightness of the star-field is well known in star catalogs, accurate …

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Characterization And Ground Test Of An Inflatable Rigidizable Space Experiment, Steven N. Lindemuth Mar 2004

Characterization And Ground Test Of An Inflatable Rigidizable Space Experiment, Steven N. Lindemuth

Theses and Dissertations

As greater capability is demanded of space-based assets, their size and complexity are growing. Inflatable, rigidizable structures offer significant improvements in the areas of weight, size, and complexity over traditional mechanically deployed systems. These structures are not well understood and little testing of them has been done in the space environment. Widespread acceptance of these technologies will not be achieved without significant reduction in the risk of using inflatable, rigidizable structures in space. The goal of this experiment is to verify and validate ground testing of small tubular truss structures for use in space. This experiment builds on previous research …

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Isomer Energy Source For Space Propulsion Systems, Benjamin L. Johnson Mar 2004

Isomer Energy Source For Space Propulsion Systems, Benjamin L. Johnson

Theses and Dissertations

Presented in this work are the results of an investigation of alternative means for powering spacecraft and launch vehicles with energy sources other than chemical combustion. Nuclear thermal propulsion and the energy release of a nuclear spin isomer present potential for increased rocket performance with compact, high-energy fuel sources replacing the combustion engines of the Delta IV-H 1st and 2nd stage vehicles. Analysis of historical fission designs along with the isomer hafnium-178-m2 in a particle bed configuration was conducted. Energy storage levels of 1.3 GJ/g are possible with this material, though the successful triggering and maintenance of a chain reaction …

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Design Of A Space Borne Autonomous Infrared Tracking System, Matthew B. Kimsal Mar 2004

Design Of A Space Borne Autonomous Infrared Tracking System, Matthew B. Kimsal

Theses and Dissertations

Complete characterization of the space environment in support of the United States goal of space Situational Awareness is not currently achievable. When confronted with recent increases in the deployment and miniaturization of microsatellites by numerous nations, the questions of foreign space capabilities are magnified. This study sought to determine the feasibility of and experimentally demonstrate a microsatellite capability to autonomously loiter about and track a target satellite. Various methods of passive remote sensing were investigated to determine the best means of detecting and tracking a target in space. Microbolometer-based infrared sensors were identified as the best alternative. A representative system …

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Modeling And Analysis Of Post-Conflict Reconstruction, Damon B. Richardson Mar 2004

Modeling And Analysis Of Post-Conflict Reconstruction, Damon B. Richardson

Theses and Dissertations

The forces at play in reconstruction operations are a complex system of time phased interlocking cause and effect relationships that are not thoroughly understood. A model capable of capturing the general dynamics involved in post-conflict reconstruction would provide insight to decision makers regarding potential policy alternatives. This research effort demonstrates the viability of using systems dynamics modeling techniques to simulate the establishment of public order and safety in a post-conflict reconstruction operation (Phase IV operations). A high level generic framework is developed that can be used as a general template for modeling post-conflict reconstruction. It is then demonstrated with a …

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