• Journal of the Korean Institute of Telematics and Electronics A
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• v.28A no.11
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• pp.910-914
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• 1991

This paper describes the improvement of frequency characteristic of crystal oscillator I.C using Ti-Salicide. The characteristics of transistor(drive current) using Ti-Salicide process are better than Poly-Si process, because the mobility. To know frequency characteristic of oscillator I.C, the simulation is performed using inverter buffer chain of Fan-out 10 TTL. Its result shows at once the generation of normal clock pulse in input signal and the improvement of rising and falling time.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.115.3-115
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• 2002

To improve the performance of the tracked vehicle system, we examined the feasibility of using the preview control for the tracked vehicles suspension system. We proposed a method to apply a linear optimal preview control to the tracked vehicle system. To avoid the complexity of modeling the track subsystem and kinematical nonlinearity in the trailing arm suspension, we classified these as unknown dynamics and disturbances. We used the Time Delay Control(TDC) method to make sprung mass dynamics follow that of linear preview controlled tracked vehicle model by compensating the uncertainties and disturbances. We have verified by the computer simulation that the proposed method shows good robus...

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.29-32
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• 2002

In this paper the wheeled mobile robot is studied. The kinematic and dynamic modeling of the robot is presented via LPD(Linear Parameter Dependent) framework. A path-planning algorithm which is optimized in the sense of robot mobility and distance is presented. And by using PI controller we show that the presented algorithm and model is work very well in the computer simulation and experiment.

• Journal of Communications and Networks
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• v.11 no.5
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• pp.509-517
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• 2009

This work proposes a new distributed and self-organized authentication scheme for mobile ad-hoc networks (MANETs). Apart from describing all its components, special emphasis is placed on proving that the proposal fulfils most requirements derived from the special characteristics of MANETs, including limited physical protection of broadcast medium, frequent route changes caused by mobility, and lack of structured hierarchy. Interesting conclusions are obtained from an analysis of simulation experiments in different scenarios.

• ETRI Journal
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• v.27 no.6
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• pp.798-801
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• 2005

This Letter proposes a scheme that supports a fast handover effectively in hierarchical mobile IPv6 networks (F-HMIPv6) by optimizing the associated data and control flows during the handover. By NS-2 simulation, we show that the proposed scheme can give better handover performance than a simple combination of existing schemes.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1647-1649
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• 2003

The electric fields of the sheath region in an argon do discharge were measured using a laser optogalvanic spectroscopy in a pressure range from 0.88 to 10 Torr, where collisions are significant in the sheath region. The sheath width is estimated as the position where the electric field becomes zero, and the pressure dependence of the measured sheath width was obtained to be $(pressure)^{-1/3}$. The measured electric fields agree well with one-dimensional simulation results but are slightly different from collisional sheath theory in the mobility limited region.

• Journal of the Korea Society for Simulation
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• v.27 no.1
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• pp.61-73
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• 2018

In the defense modeling and simulation, for the detailed analysis of the communication system, many studies have carried out the analysis under the C3 SoS(system of systems) which consists of C2(command and control) and C(communication). However, it requires time and space constraints of the C2 system. To solve this problem, this paper proposes a communication analysis method in the standalone system environment which is combined with the C system after abstracting the C2 system. In the abstraction process, we hypothesize the traffic model and mobility model for C system analysis and learn the parameters in the model based on machine learning. Through the proposed method, it is possible to construct traffic and mobility model with different output according to the battlefield. This case study shows how the process can be applied to the C3 SoS and the enhanced accuracy than the existing method. We expect that it is possible to carry out the efficient communication analysis against many experimental scenarios with various communication parameters.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.267-270
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• 2002

The fluoescent lamp has been successfully modeled by employing the radial variation of particle density and considering driving circuit effects on the characteristics of discharge process. The electron energy distribution is assumed to have a Maxwellian. The electron mobility and the ambipolar diffusion coefficients are considered to vary with an electron energy rather than a simple uniform value. Energy states of mercury atom in the discharge process are regarded as six levels rather than simple 4 or 5 levels. These discharge processes have been accurately solved by numerically employing mixed the FDM and the 2nd Runge-Kutta method. This model was applied to analyzing real circuit. Simulation and experimental results were presented to verify the feasibility of the modeling. Simulation and experimental results were presented to verify the feasibility of the modeling.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.1
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• pp.93-102
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• 1994

This paper, presents SECRET(SEC REliability Tool), which predicts reliability problems related to the hot-carrier and electromigration effects on the submicron MOSFETs and interconnections. To simulate DC and AC lifetime for hot-carrier damaged devices, we have developed an accurate substrate current model with the geometric sensitivity, which has been verified over the wide ranges of transistor geometries. A guideline can be provided to design hot-carrier resistant circuits by the analysis of HOREL(HOT-carrier RFsistant Logic) effect, and circuit degradation with respect to physical parameter degradation such as the threshold voltage and the mobility can also be expected. In SECRET, DC and AC MTTF values of metal lines are calculated based on lossy transmission line analysis, and parasitic resistances, inductances and capacitances of metal lines are accurately considered when they operate in the condition of high speed. Also, circuit-level reliability simulation can be applied to the determination of metal line width and-that of optimal capacitor size in substrate bias generation circuit. Experimental results obtained from the several real circuits show that SECERT is very useful to estimate and analyze reliability problems.

• KIEAE Journal
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• v.12 no.2
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• pp.33-38
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• 2012

This study aims to evaluate the structural safety of the balcony photovoltaic systems easily installed or moved on the buildings. Also, the systems are controlled by solar altitudes focused on its mobility rather than high efficiency generation performance thereof. The results of the study are as follows. Two types of typical photovoltaic systems which can be mounted on the balcony are proposed, and, the sizes of the systems are designed to be adjusted within certain ranges of the frames in order to attach the various rail sizes. To evaluate the structural safety of the proposed systems, several simulation evaluations are performed on the safety evaluation standards by the Ministry of Construction-Transportation and KCI 2007. The results are that the proposed plans are reasonable in terms of stress and deflection in the structural aspects at the wind pressures of $1,907(N/m^2)$ of external wall surface under the condition of wind velocity higher than 25(m/s).