• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.137-137
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• 2000

In this research. we developed Tire Roller Prototype which is operated hydraulic transmission system. For develop the theoretically computer aided system, we practiced the simulation of hydraulic system and dynamic modeling and will compare with the experiment results of Tire Roller Prototype. We conceptualize the new hydraulic system and derive the equations of motion for dynamic analysis. Finally, we will design the controller, which can manage the hydraulic circuit of servo mechanism system. We define new hydraulic system and integrate modeling of Tire Roller through simulation of h\ulcornerdraulic system and design of controller. From above procedure. Hydraulic transmission system characteristics and target performance can be investigated. To follow the required performance, we select the parts of Tire Roller. We manufactured the prototype of Tire Roller, and will install the equipment for experiment.

• International Journal of Automotive Technology
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• 제7권2호
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• pp.161-166
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• 2006

This paper presents shift characteristics of a dual clutch transmission(DCT). To obtain the shift force, dynamic models of the DCT are constructed by using MATLAB/Simulink and considering the rotational inertia of every component and the target pre-select time. Dynamic models of the shift and clutch actuators are derived based on the experimental results of the dynamic characteristics test. Based on the dynamic model of the DCT synchronizer, control actuator and vehicle model, a DCT vehicle performance simulator is developed. Using the simulator, the shift force and speed of the relevant shafts are obtained. In addition, the torque and acceleration of actuators are calculated during the shift process by considering the engaging and disengaging dynamics of the two clutches. It is observed from the performance simulator that uninterrupted torque can be transmitted by proper control of the two clutches.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 춘계학술대회
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• pp.641-644
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• 2017

LTE(Long Term Evolution) 기술은 스마트폰 중심의 모바일 인터넷으로 상징되는 상용 통신을 넘어 산업 및 긴급 통신 분야로 사용이 확대되고 있다. 본 논문에서는 다양한 분야로 보급되고 있는 LTE 기술의 전송 성능을 응용 트래픽 수준에서 분석해 본다. 성능 분석은 NS-2를 기반으로 한 컴퓨터 시뮬레이션을 사용하여 수행하며, CBR(Constant Bit rate), VBR(Variable Bit Rate) 등의 트래픽을 분석 대상으로 한다. 본 논문의 결과와 방법은 LTE 기반 네트워크의 연구 및 개발에 활용될 수 있을 것으로 생각된다.

• ETRI Journal
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• 제37권5호
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• pp.898-905
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• 2015

In this paper, we consider a joint beamforming and jamming design to enhance physical layer security against potential multiple eavesdroppers in a multiple-input and single-output cellular broadcast channel. With perfect channel state information at the base station, we propose various design approaches to improve the secrecy of the target user. Among the proposed approaches, the combined beamforming of maximum ratio transmission and zero-forcing transmission with a combination of maximum ratio jamming and zero-forcing jamming (MRT + ZFT with MRJ + ZFJ) shows the best security performance because it utilizes the full transmit antenna dimensions for beamforming and jamming with an efficient power allocation. The simulation results show that the secrecy rate of this particular proposed approach is better than the rates of the considered conventional approaches with quality-of-service and outage probability constraints.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.598-599
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• 2007

The electricity supply industry for which high stability and quality of power are the primary aim of power company and the first order of business target. As the facilities of generations, transmissions and substations are increased every year, power system becomes more complex and hard to control. The complexity of the power system causes harmful influence on its security and power facilities. Moreover, difficulty of predicting weather condition in these days with its complexity increases the level of uncertainty of energy demand. Wide area online monitoring of power system offers lots of informations and solutions which clear the causes of insecurity in power system. In this paper, we presents the development of synchrophasor data measurement and transmission system using satellite network for power system online monitoring.

• Journal of Positioning, Navigation, and Timing
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• 제7권4호
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• pp.227-233
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• 2018

The purpose of satellite navigation meaconing jamming is to make the target GPS receiver calculate false navigation by meaconing the received satellite signals. At this time, since the received and transmitted signals have the same frequency, the back-lobe reduction level of antenna should be -160 dB when the Effective Radiated Power (ERP) is 1 Watt (30 dBm). Therefore, meaconing jamming is impossible by merely reducing the back-lobe level of antenna when the transmitter and receiver are in proximity to each other. In general, the transmitter and receiver are isolated by the time division method to eliminate such transmission/reception interference. This paper studied the optimal switching timing between transmitting and receiving when isolating the time division transmission and reception for GPS meaconing jamming.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2019년도 춘계학술대회
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• pp.456-458
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• 2019

본 연구에서는 LTE-R을 기반으로 하는 철도통신에서 응용서비스로서 스트리밍 오디오의 전송성능을 분석하고자 한다. 본 연구에서 성능분석은 NS(Network Simulator)-3에 기반한 컴퓨터 시뮬레이션을 사용하여 수행하며, 분석대상 응용서비스로는 MPEG(Moving Picture Experts Group)-4의 오디오 프레임을 사용한다. 본 연구의 결과는 LTE-R 네트워크 구축뿐 아니라 LTE-R 네트워크를 대상으로 하는 응용서비스 개발의 기초자료로 활용이 가능하다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.64-67
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• 2003

The authors have settled general modular design by analyzing related literatures, but general modular design are too massive to be applicable to all process devices. So, the common parts have to be selected, applied, and modified for the devices. We have chosen the dry pulverizing/mixing device for example. We have elected the target modules of this device such as flange, hinge, bolt, nut coupling. The remote assembling and disassembling possibilities of the selected modules have been analyzed from the viewpoints of visibility, interference, approach, weight and so on. We have presented final modular design proper to the target modules. The modular designs which have adopted the modular property been analyzed. The modular design points are comprised of common and unique points. Some points are common for several devices, such as bolt, flange and so on. Others are unique for each device, such as power transmission coupling. The experimental devices have been modified by these modular design points and the design drawings have been presented.

• 전기학회논문지
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• 제56권6호
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• pp.1111-1116
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• 2007

Antennas of the near field detection radar require little distortion in time domain caused by multi reflections between feed and open ends of the antenna, so that help to discriminate the target signal from the clutters. The resistive loading techniques have been used to reduce the late time distortions in order to prevent masking of target. In this paper, we design a microstrip antenna with two arms having sloted lines, which have inductance loading effect. Implemented antenna shows better performance on reducing late-time ringing, and the peak value of the received signal becomes 45% greater than the one by the antenna with two non-sloted lines.

• 한국자동차공학회논문집
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• 제4권2호
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• pp.90-105
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• 1996

A real tine simulator of running power train for a construction vehicle was developed. The simulator mainly consists of following two parts; (1) running power train part and (2) running load generation part. An optimal servo control algorithm was adopted for designing the multi-variable digital control system of the simulator. By experiments investigating response characteristics under step-wise variation or pre-determined scenario of target vehicle velocity and target load torque, it was verified that the simulator could reproduce physical situations at and actual vehicle with excellent similarity.