• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.1
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• pp.83-93
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• 2017

Recently, the development of multi-purpose tunnel that has functions of roads and waterways has been attention for efficient utilization of underground space. However, there is no study on the multi-functional tunnels behavior for the convert of iterative function and change of water pressure. In this study, the vulnerable section was analyzed due to repeated functional change. A basic review was implemented for the operation of the multi-purpose double-deck tunnel. Also, the vulnerable section for convert of iterative function of multi-functional tunnel has been analyzed by simulation. Management of multi-functional tunnel should considered in various analyzed and some problems. The criteria for management of multi-functional tunnels is proposed.

• Advances in robotics research
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• v.1 no.1
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• pp.101-126
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• 2014

In this article we present modular neural control for a leg-wheel hybrid robot consisting of three legs with omnidirectional wheels. This neural control has four main modules having their functional origin in biological neural systems. A minimal recurrent control (MRC) module is for sensory signal processing and state memorization. Its outputs drive two front wheels while the rear wheel is controlled through a velocity regulating network (VRN) module. In parallel, a neural oscillator network module serves as a central pattern generator (CPG) controls leg movements for sidestepping. Stepping directions are achieved by a phase switching network (PSN) module. The combination of these modules generates various locomotion patterns and a reactive obstacle avoidance behavior. The behavior is driven by sensor inputs, to which additional neural preprocessing networks are applied. The complete neural circuitry is developed and tested using a physics simulation environment. This study verifies that the neural modules can serve a general purpose regardless of the robot's specific embodiment. We also believe that our neural modules can be important components for locomotion generation in other complex robotic systems or they can serve as useful modules for other module-based neural control applications.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.2
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• pp.8-17
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• 2008

This paper presents the Matlab/Simulink-based software-in-the-loop simulation(SILS) environment which is the co-simulator for temporal and functional simulations of control systems. The temporal behavior of a control system is strongly dependent on the implemented software and hardware such as the real-time operating system, the target CPU, and the communication protocol. The proposed SILS abstracts the system with tasks, task executions, real-time schedulers, and real-time networks close to the implementation. Methods to realize these components in graphical block representations are investigated with Matlab/Simulink, which is most commonly used tool for designing and simulating control algorithms in control engineering. In order to achieve a seamless development from SILS to rapid control prototyping (RCP), the SILS block-set is designed to support automatic code generation without tool changes and block modifications.

• Journal of the Korea Society for Simulation
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• v.19 no.4
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• pp.281-289
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• 2010

Recently the intelligent agent systems have been emerged as one of key issues for developing the defense M&S systems. However, most conventional agent architecture of M&S systems utilize the script-based models and can only deal with the individual behaviors so that they cannot suitably describe the precise tactical/strategic behavior and/or complex warfare environment. To overcome these problems, we have proposed the HEAP(Hierarchical Encapsulation and Abstraction Principle)-based hierarchical multi-agent system architecture that is able to intelligently cope with the complex missions based on the functional role of each agent on the hierarchy such as an intelligence officer, captain, commander.

• Journal of Magnetics
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• v.18 no.3
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• pp.245-249
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• 2013

A finite element model was built for MnBi/${\alpha}$-Fe nanocomposite permanent magnets, and the demagnetization curves of the magnets were simulated by micro-magnetic calculation. The microstructure of the cubic model is composed of 64 irregular grains with an average grain size of 20 nm. With the volume fraction of soft magnetic phase (t vol. %) ranged from 5 to 20 vol. %, both isotropic and anisotropic nanocomposite magnets show typical single-phase permanent magnets behavior in their demagnetization curves, illustrating good intergranular exchange coupling effect between soft and hard magnetic phases. With the increase of volume fraction of soft magnetic phase in both isotropic and anisotropic magnets, the coercive force of the magnets decreases monotonically, while the remanence rises at first to a peak value, then decreases. The optimal values of maximum energy products of isotropic and anisotropic magnets are 84 and $200kJ/m^3$, respectively. Our simulation shows that the MnBi/${\alpha}$-Fe nanocomposite permanent magnets own excellent magnetic properties and therefore good potential for practical applications.

• Journal of the Korea Society for Simulation
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• v.32 no.3
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• pp.9-21
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• 2023

The recent conflict between Russia and Ukraine underscores the significant of military logistics support in modern warfare. Military logistics support is intricate and specialized, and traditionally centered on the mission-level operational analysis and functional models. Nevertheless, there is currently increasing demand for military logistics support even at the engagement level, especially for resupply using unmanned transport assets. In response to the demand, this study proposes a task model of the military logistics support for engagement-level analysis that relies on the logic of ammunition resupply below the battalion level. The model employs a decisions tree to establish the priority of resupply based on variables such as the enemy's level of threat and the remaining ammunition of the supported unit. The model's feasibility is demonstrated through a combat simulation using OneSAF.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.1 no.1
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• pp.51-59
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• 1991

Early stage of GaAs nucleation on Si substrate was theoretically studied by computer simulation. Compared to the constant ledge interaction energy in conventional nucleation theory, functional behavior of ledge-ledge interaction resulted in small size clusters depending on the cluster size and shape. Among various kinds of clusters, the multilayer pyramidal shape GaAs cluster requires smallest excess free energy due to the formation of Ga(111) facet planes. There this result suggests that the defects involved in GaAs/Si are originated from the early stage nucleation.

• Carbon letters
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• v.25
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• pp.55-59
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• 2018

Carbon chain inserted carbon nanotubes (CNTs) have been experimentally proven having undergone pronounced property change in terms of electrical conductivity compared with pure CNTs. This paper simulates the geometry of carbon chain inserted CNTs and analyzes the mechanism for conductivity change after insertion of carbon chain. The geometric simulation of Pt doped CNT was also implemented for comparison with the inserted one. The results indicate that both modification by Pt atom on the surface of CNT and addition of carbon chain in the channel of the tube are effective methods for transforming the electrical properties of the CNT, leading to the redistribution of electron and thereby causing the conductivity change in obtained configurations. All the calculations were obtained based on density functional theory method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.9
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• pp.1642-1651
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• 2008

The dynamic behavior of power systems is affected by the interactions between linear and nonlinear components. To analyze those complicated power systems, the linear approaches have been widely used so far. Especially, a synchronous generator has been designed by using linear models and traditional techniques. However, due to its wide operating range, complex dynamics, transient performances, and its nonlinearities, it cannot be accurately modeled as linear methods based on small-signal analysis. This paper describes an application of the Takaki-Sugeno (T-S) fuzzy method to model the synchronous generator in a single-machine infinite bus (SMIB) system. The T-S fuzzy model can provide a highly nonlinear functional relation with a comparatively small number of fuzzy rules. The simulation results show that the proposed T-S fuzzy modeling captures all dynamic characteristics for the synchronous generator, which are exactly same as those by the conventional modeling method.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.625-626
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• 2006

This paper presents the new simulation model for the performance analysis of Surface-Mounted Permanent Magnet Synchronous Motor(SMPMSM) Drive System which is integrated with a controller and a power converter. To enhance reusability and compatibility, the system model is expressed by the association of independent sub-modules reflecting the real physical construction. This concept allows another independent sub-module to be effectively inserted in the model for the comprehensive analysis of larger systems such as a Machine Tool and HEV. The developed model which is composed of MATLAB/Simulink's basic blocks can rapidly analyze not only the entire behavior of system, but also the functional relationship between each components for the effective development of controller.