• Journal of the Korea Society for Simulation
• /
• v.25 no.4
• /
• pp.117-126
• /
• 2016

We suggest the C2 modeling method to develop a simulation model for training command groups which consist of commanders and staffs. By using C2 models in constructive simulation models, combat entities or units directly receive and execute orders from a command group without mediating human role players. We also compare combat results from suggested modeling method with the results of existing models by building and implementing a simulation model with C2 models. Our analysis by comparison demonstrates advantages of suggested method to model C2 for computer assisted exercises.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2003.11a
• /
• pp.185-192
• /
• 2003

Digital Manufacturing-based production could be very effective in shipbuilding in order to save costs and time, to increase safety for workers, and to prevent bottleneck processes in advance. Digital shipbuilding system, a simulation-based production tool, is being developed to achieve such aspects in Korea. To simulate material flow in a subassembly line at a shipyard, the product, process and resources was modeled for the subassembly process which consisted of several sub-processes such as tack welding, piece alignment, tack welding, and robot welding processes. The analysis and modeling were carried out by using the UML(Unified Modeling Language), an object-oriented modeling method as well as IDEF(Integration DEFinition), a functional modeling tool. Initially, the characteristics of the shop resources were analyzed using the shipyard data, and the layout of the subassembly line was designed with the resources. The production process modeling of the subassembly lines was performed using the discrete event simulation method. Using the constructed resource and process model, the productivity and efficiency of the line were investigated. The number of workers and the variations In the resource performance such as that of a new welding robot were examined to simulate the changes in productivity. The bottleneck process floated according to the performance of the new resources. The proposed model was viewed three-dimensionally in a digital environment so that interferences among objects and space allocations for the resources could be easily investigated

• Journal of the Korean Society of Systems Engineering
• /
• v.20 no.1
• /
• pp.76-84
• /
• 2024

This study investigates the design of an optical observation system for continuously tracking unknown space object targets within the telescope's field of view at a short cycle rate of several to tens of frames per second. Through modeling and integrated simulation by design variables, we aim to identify combinations that satisfy the performance effectiveness scale. The study demonstrates the effectiveness of a model-based simulation analysis approach in rapidly identifying design parameters that meet specific performance requirements. By leveraging numerical models tailored to the desired performance analysis level, the approach provides a robust foundation for decision-making, eliminating reliance on empirical methods or vague estimations.

• Transactions of Materials Processing
• /
• v.29 no.5
• /
• pp.265-271
• /
• 2020

The purpose of this paper is to analyze the numerical simulation accuracy according to the CFRP modeling method in the CFRP-Al alloy SPR (Self-Piercing Rivet) joint process. The mechanical properties of the CFRP, aluminum sheet are precisely obtained from the tensile test according to the loading direction. Additionally, the hardening curve of rivet was calculated from the inverse analysis of the machined rivet-ring compression test. For the CFRP-Al alloy SPR simulation, two kinds of the CFRP modeling methods were established based on the continuum and layer-by-layer approaches. The simulation results showed that the CFRP layer-by-layer modeling method can provide more reliable prediction shape of the fractured sheets and deformed rivet. This simulation technique can be used in evaluating the CFRP-Metal SPR performance and designing the SPR process conditions.

• Proceedings of the KIPE Conference
• /
• 2000.07a
• /
• pp.525-528
• /
• 2000

This paper presents a circuit analysis and cotnrol example of favored configuration 6/4 SRM. SRM modeling and analysis are necessary for experiment. Thus this paper proposes a SRM modeling with PI controller (of driving converter) input voltage chopping and inductance profile when rotor position transformed. Through this simulation the designer can predict operating states of systems over a broad range of operating conditions.

• Journal of the Korea Society for Simulation
• /
• v.3 no.1
• /
• pp.151-165
• /
• 1994

Broadband network based on the Asynchronous Transfer Mode(ATM) concept are becoming the target technology for the emerging Broadband Integrated Services Digital Network(B-ISDN). Since B-ISDN is very complex and requites a great amount of investment, optimum design and performance analysis of such systems are very important. Simulation can be widely used to analyze and examine the broadband network behavior. However, for the complicated system like broadband networks it is extremely difficult and time-consuming to develop a complete model for simulation. In this paper, an object-oriented modeling approach for the broadband network simulation is presented for the effective and efficient modeling. Object-oriented approaches can provide a good structuring capability for complicated simulation models and facilitate the development of reusable and extensible simulation models. We have developed an object-oriented model which consists of object model and behavior model. In the object mode., the components of the broadband network and both constant bit rate(CBR) and variable bit rate(VBR) traffic types of call level, burst level, and cell level are modeled as object classes. In the behavior model, the dynamic features for each object class are represented using the state transition diagram. It has been shown by illustration that objectoriented modeling is an effective tool for modeling the complicated B-ISDN.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.36 no.11
• /
• pp.1112-1120
• /
• 2008

The real-time distributed simulation at the present age concentrates on the construction of a system development environment in order to accomplish a synthetic battlefield environment connected with Live-Virtual-Constructive simulation and to realize the Simulation Based Acquisition which supports the life cycle of weapon system. Accordingly this paper describes the development environment of the UML modeling and simulation which integrates the system analysis and design methods performed during the conceptual design phase of the reconnaissance UAV system development. An integrated framework linked with the UML simulation and X-plane visualization is suggested to efficiently perform the system analysis and design, and finally the implementation contents, the analysis of experiment results and concluding remarks are described.

• Journal of Advanced Navigation Technology
• /
• v.8 no.2
• /
• pp.155-162
• /
• 2004

Recently, significant interest is shown to creation rather inexpensive global systems communications on base of Low-Earth-Orbit Satellite Networks (LEOSN). One of problems of design and creation LEOSN is development of the stream control methods and estimation it's efficiency in such networks. The given problem is complicated, that the topology of the satellite networks varies in time. It essentially hinders the analytical decision of the given problem. An effective way of overcoming of these difficulties is simulation modeling. For realization of research experiments on learning the information streams routing algorithms in LEOSN a special program complex SANET was developed. In the given paper principles of development of LEOSN simulation models and architecture of the manager by the process of a simulation modeling of the unit are considered. Methods of promotion of modeling time and architecture of a simulator complex offered in the article allow to boost essentially efficiency of simulation analysis and to ensure simulation modeling of the satellite networks consisting of several hundreds space vehicles.

• Journal of Ocean Engineering and Technology
• /
• v.34 no.5
• /
• pp.316-324
• /
• 2020

This paper presents comparative studies of reliability analysis and meta-modeling using the sampling method of Monte Carlo simulation for the structure design of an automatic ocean salt collector (AOSC). The thickness sizing variables of structure members are considered as random variables. Probabilistic performance functions are selected from strength performances evaluated via the finite element analysis of an AOSC. The sampling methods used in the comparative studies are simple random sampling and Sobol sequences with varied numbers of sampling. Approximation methods such as the Kriging model is applied to the meta-model generation. Reliability performances such as the probability failure and distribution are compared based on the variation of the sampling method of Monte Carlo simulation. The meta-modeling accuracy is evaluated for the Kriging model generated from the Monte Carlo simulation and Sobol sequence results. It is discovered that the Sobol sequence method is applicable to not only to the reliability analysis for the structural design of marine equipment such as the AOSC, but also to Kriging meta-modeling owing to its high numerical efficiency.

• Steel and Composite Structures
• /
• v.10 no.2
• /
• pp.129-149
• /
• 2010

The objective of this study is to formulate a general 3D material-structural analysis framework for the thermomechanical behavior of steel-concrete structures in a fire environment. The proposed analysis framework consists of three sequential modeling parts: fire dynamics simulation, heat transfer analysis, and a thermomechanical stress analysis of the structure. The first modeling part consists of applying the NIST (National Institute of Standards and Technology) Fire Dynamics Simulator (FDS) where coupled CFD (Computational Fluid Dynamics) with thermodynamics are combined to realistically model the fire progression within the steel-concrete structure. The goal is to generate the spatial-temporal (ST) solution variables (temperature, heat flux) on the surfaces of the structure. The FDS-ST solutions are generated in a discrete form. Continuous FDS-ST approximations are then developed to represent the temperature or heat-flux at any given time or point within the structure. An extensive numerical study is carried out to examine the best ST approximation functions that strike a balance between accuracy and simplicity. The second modeling part consists of a finite-element (FE) transient heat analysis of the structure using the continuous FDS-ST surface variables as prescribed thermal boundary conditions. The third modeling part is a thermomechanical FE structural analysis using both nonlinear material and geometry. The temperature history from the second modeling part is used at all nodal points. The ABAQUS (2003) FE code is used with external user subroutines for the second and third simulation parts in order to describe the specific heat temperature nonlinear dependency that drastically affects the transient thermal solution especially for concrete materials. User subroutines are also developed to apply the continuous FDS-ST surface nodal boundary conditions in the transient heat FE analysis. The proposed modeling framework is applied to predict the temperature and deflection of the well-documented third Cardington fire test.