Se Jung Kwon

Measurement of Effectiveness for an Anti-torpedo Combat System Using a Discrete Event Systems Specification-based Underwater Warfare Simulator

Modeling and simulation (M&S) has long played an important role in developing tactics and evaluating the measure of effectiveness (MOE) for the underwater warfare system. In simulation-based acquisition, M&S technology facilitates decisions about future equipment procurements, such as a mobile decoy or a torpedo. In addition, assessment of submarine tactical development, during an engagement against a torpedo, can be conducted using M&S techniques. This paper presents a case study that applies discrete event systems specification-based M&S technology to develop a simulation of an underwater warfare system, specifically, an anti-torpedo combat system, to analyze the MOE of the system. The entity models required for M&S are divided into three sub-models: controller, maneuver, and sensor model. The developed simulation allows us to conduct a statistical evaluation of the overall underwater warfare system under consideration, an assessment of the anti-torpedo countermeasure’s effectiveness, and an assessment of tactics development of the underwater vehicle. Moreover, it can be utilized to support the decision-making process for future equipment procurements. In order to analyze the system effectiveness, we performed extensive combat experiments by varying parameters, such as various tactics and weapon performance. The experimental results show how the factors influence the MOEs of the underwater warfare system.

Effectiveness Analysis of Anti-torpedo Warfare Simulation for Evaluating Mix Strategies of Decoys and Jammers

Modeling and Simulation (M&S) engineering has been widely used for design and evaluation of underwater warfare systems. M&S engineering enables more efficient procurement of military equipment by analyzing these systems with simulations. This paper extends previous work, which used an anti-torpedo simulator with only decoys. To facilitate more diverse simulations of anti-torpedo combat, we design and add a simple jammer model, because the jammer is one of the most effective counter-measures against torpedo attacks. Utilizing this proposed model, we collect experimental data about the survivability of surface-ships that use anti-torpedo strategies and analyze the proper parameter values of jammers that satisfy the required Measure of Effectiveness (MOE). The experimental results show both the required performance of jammers and the efficiency of jammers with decoys. The results can be utilized to support the decision-making process for future equipment procurement.

Modeling and Simulation Methodology for Defense Systems Based on Concept of System of Systems

Tag Gon Kim․Se Jung Kwon․Bonggu KangDepartment of Electrical Engineering, KAISTA complex system such as defense systems is in a form of System of Systems (SoS) in which each component is a system being independent of other component systems. Dynamical behavior of SoS is represented by a composition of behaviors of component systems. Thus, a M&S tool/environment would not be efficient for deve-lopment of heterogeneous models nor for simulation in a centralized environment. Moreover, such an envi-ronment restricts reusability and composability. This paper presents an interoperation method for M&S of defense systems as SoS. The approach first develops component system models using tools, each specialized to M&S of each component system. It then interoperates such simulations together to simulate a whole system as SoS. HLA/RTI is employed for such interoperation, which is a DoD/IEEE standard to support interoperation. We will introduce a case study for interoperable simulation of defense systems, which consists of a wargame simulator and a communication simulator.

Integrated Hybrid Modeling Methodology and Simulation Engine Design Based on HDEVS Formalism

A hybrid system is a combination of sub systems which have different types of state and time: a typical example is a combination of discrete event and continuous systems. A HDEVS(Hybrid DEVS) formalism was proposed for modeling and analyzing a hybrid system. The HDEVS formalism allows modelers to construct a hierarchical and modular model based on the mathematical set theory. Because the HDEVS formalism was applied to the distributed and interoperated simulators, modelers should make several heterogenous models dividing a target system. Hence, this paper proposes an extended hybrid coupled model of HDEVS formalism and an integrated hybrid modeling methodology in contrast to the existing simulation framework on interoperable simulators. By applying the proposed modeling method, a target system can be translated to a hybrid model in a similar form as the target system. This paper also contains a simulation engine design for the proposed modeling methodlogy and a case study which simulates water tank control systems.

Design, Implementation and Performance Analysis of Event-oriented Execution Environment for DEVS

DEVS(Discrete Event Systems Specification) is a set theoretic formalism developed for specifying discrete event system. For execution of DEVS, we need an execution environment, which consists of simulation engine and models interpreted by the simulation engine. Common existing environments use hierarchical scheduling algorithm for DEVS execution. This hierarchical scheduling is a proper algorithm for DEVS execution because of hierarchical and modular characteristics. But this algorithm has overheads owing to message passing and time management. To overcome these overheads, we apply event-oriented simulation to DEVS execution and we remove hierarchical overheads. In eventoriented simulation, the scheduling of model execution is performed by events and event list. We propose three event-oriented execution environments for DEVS and experiment about the performance of our proposed environments in comparison with the existing execution environment using the hierarchical scheduling. The experimental results show our environments works better than existing environment using the hierarchical scheduling.

Adaptive Discrete Event Simulation Systems to Embrace Changes of Requirements Using Event Control Models

During the development or deployment of discrete event simulation systems, many sudden changes in requirements emerge. To embrace the changes rapidly and reduce development costs, attaching reusable, and black-boxed components to existing systems has been regarded as one of the most effective approaches because modifications at the code level are generally costly and risky. However, since this approach requires components that are an exact fit, it may not be easy to avoid the modifications at the source code level actually. Moreover, the required components may not exist. Hence, this paper applies black-box extensibility to simulation systems in order to avoid the modifications. This paper proposes adaptive discrete event simulation systems using event control models for extending and modifying semantics through event-based simulation interface. With the proposed work, the simulation events are modulated, deleted, and generated by the event-oriented control functions in the event control model to embrace the changes of requirements. It can substitute for the modifications at the code level and extend the existing behavioral semantics. As a result, the proposed work provides a new alternative step in the development process with reusable components to avoid modifications at the source code level. The new step will lead to rapid adaptations of existing simulation systems. To support the effectiveness of this approach, this paper will describe applicable examples based on our empirical studies.

Multi-fidelity Modeling and Simulation Methodology to Enhance Simulation Performance of Engineering-level Defense Model

This paper presents multi-fidelity modeling and simulation (M&S) methodology to enhance simulation performance of engineering-level defense models. In this approach, a set of models with varying degrees of fidelity is exercised to reduce computational expense maintaining a similar level of system effectiveness. For multi-fidelity M&S principles, this paper defines model fidelity from two perspectives (i.e., model behavior and execution), and suggests the Fidelity Change Point (FCP) to specify the fidelity conversion. With these concepts, this paper centers on three ideas: 1) two models’ structure which are the Behavioral-Fidelity Interchangeable Model (B-FIM) and the Executional-Fidelity Interchangeable Model (E-FIM), 2) modeling formalism, and 3) a simulation algorithm to support them. From an

Extendable Simulation Framework for Virtual World Environment Based on the DEVS Formalism

A virtual world is an interactive virtual environment in which users interact with each other with computers, and can be used as a platform for virtual training activities. In order to enhance the trainee’s immersive experience, domain-specific simulation models are required for virtual world services. For this reason, we propose an extendable simulation framework for the virtual world. The simulation framework is composed of Core Simulation Framework and Virtual Level Architecture. By utilizing the Core Simulation Framework and the Virtual Level Architecture, the content creator of the virtual world can create extendable simulations for domain-specific content.