• Journal of Positioning, Navigation, and Timing
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• 제7권2호
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• pp.73-90
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• 2018

Various navigation systems are integrated with the Global Navigation Satellite System (GNSS) to improve navigation performance so that continuous navigation information can be obtained even when navigation performance is degraded or navigation is not available due to the outage of GNSS. Time and cost can be reduced by evaluating performance of the integrated navigation system through Modeling and Simulation (M&S) software prior to the deployment of the integrated navigation system. The measurements of the navigation system should be generated to evaluate performance through of the navigation system M&S software. This paper proposes a method of designing a navigation environment generation module in M&S software of the integrated navigation system. To show applicability of the proposed method to M&S software design of the integrated navigation system, functions are verified through MATLAB. And then visual C++ based M&S software for the integrated navigation system is implemented to check the operation of the navigation environment generation module. The reference trajectory is generated and true measurements of Global Positioning System (GPS), Korea Positioning System (KPS), and enhanced Long range navigation (eLoran) are generated from the reference trajectory. The navigation results obtained from the true measurements are compared with the reference trajectories. The results show that the measurements generated using the design generation module by the proposed method are valid and the navigation environment generation module can be applied to M&S software of the integrated navigation system.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 춘계학술대회
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• pp.289-290
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• 2021

최근 4차 산업혁명의 도래로 로봇의 역할이 커지고 있으며, 서비스 분야에도 로봇의 활용이 증가하고 있다. 로봇과 관련된 비선형(nonlinear) 연구에 있어서 가장 대중적인 모델이 역진자(inverted pendulum) 시스템이라 할 수 있다. 역진자 시스템을 응용한 밸런싱 로봇(balancing robot)은 대표적인 비선형 시스템으로 제어이론 및 기타 기구학적 구조를 연구하는 데 주로 활용되고 있다. 본 논문에서는 밸런싱 로봇제어를 위하여 필요한 3축 가속도 센서(ADXL345) 및 3축 디지털 출력 자이로 센서(ITG-3200) 또는 HMC5883L를 활용하여 로봇의 상태를 계측하도록 하며, ESP32-WROOM-32 모듈을 활용하여 밸런싱 로봇을 제어할 수 있는 MCU 모듈을 설계하고자 한다. 또한 ESP32-WROOM-32 MCU 모듈을 활용하여 밸런싱 로봇의 상태를 WiFi 또는 Bluetooth 기반으로 모니터링할 수 있는 MCU 모듈을 설계하고자 한다.

• Transactions on Electrical and Electronic Materials
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• 제15권5호
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• pp.279-283
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• 2014

In this paper, we present an economical and practical standard to install a bypass diode in a thin-film PV module. This method helps to reduce heat generation and to prevent module degradation due to excess current from reverse bias. The experimental results confirm that for different numbers of solar cells, there is a relation between the excess reverse current and the degradation of solar cells in a-Si:H modules. The optimal number of solar cells that can be connected per bypass diode could be obtained through an analysis of the results to effectively suppress the degradation and to reduce the heat generated by the module. This technique could be expanded for use in high power crystalline Si PV modules.

• ETRI Journal
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• 제20권3호
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• pp.284-300
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• 1998

A new thermosyphon cooling module (TSCM) has designed, fabricated and tested to cool the multi-chip module consists of a cold plate and an integrated condenser. With an allowable temperature rise of $56^{\circ}C$ on the surface of the heater, the cooling module TSCM can handle a heat flux of about 2.7 $W/cm^2$ using R11 as working fluid. The transient characteristics of the cooling module have been proved to be excellent: that is, when a heat load is applied inside of the system, steady state can be achieved within 10 to 15 minutes. It has been found that the length of the vapor channel between the cold plate and the condenser in addition to the ambient and the condenser temperatures affect the system performance.

• ETRI Journal
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• 제42권4호
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• pp.527-533
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• 2020

High-level synthesis (HLS), which automatically synthesizes a register-transfer level (RTL) circuit from a behavioral description written in a high-level programming language such as C/C++, is becoming a more popular technique for improving design productivity. In general, HLS tools often generate a circuit with a larger area than those of hand-designed ones. One reason for this issue is that HLS tools often generate multiple instances of the same module from a function. To eliminate such a redundancy in circuit area in HLS, HLS tools are capable of sharing modules. Function-level module sharing at a behavioral description written in a high-level programming language may promote function reuse to increase effectiveness and reduce circuit area. In this paper, we present two HLS techniques for module sharing at the function level.

• 한국초전도ㆍ저온공학회논문지
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• 제20권1호
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• pp.15-18
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• 2018

In this paper, the magnetizing characteristics of the current limiting reactor (CLR) using $high-T_C$ superconducting (HTSC) module were analyzed. Since the saturation of iron core comprising the CLR using HTSC module deteriorates its current limiting operation, the design of the CLR using HTSC module considering the magnetizing characteristics is needed. For the analysis on the magnetizing characteristics, the flux linkage and the magnetizing current of this CLR using HTSC module were derived from its electrical equivalent circuit. Through the analysis on the linkage flux versus the magnetizing current, obtained from the short-circuit tests, the suppressing effect of the iron core's saturation was discussed.

• 한국정밀공학회지
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• 제17권10호
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• pp.170-179
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• 2000

The objective of this study is to develop an analytical module for the prediction of burr formation during cutting process using the finite element method. This module is based on the rigid-plastic finite element method, ductile fracture criterion, fracture propagation technique and node separation criterion. The sequence of burr formation from burr initiation through end of burr formation is simulated and investigated by this module. The effect of material properties, such as AL6061-T6, AL2024-T4 and Copper, and cutting condition, such as rake angle and cutting depth, on burr formation is also discussed in this study. To validate this module the analysis results are compared with experimental ones.

• 한국정밀공학회지
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• 제21권8호
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• pp.50-56
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• 2004

The directional ability of an automobile has an influence on driver directly, and hence it must be given most priority. Alignment factors of automobile such as the camber, caster and toe directly affect the directional ability of a vehicle. The above mentioned factors are determined by the pose of interlinks in the assembly of an automobile front chassis module. Measuring the position of center point of ball joints in the front lower arm is very difficult. A method to determine this position is suggested in this paper. Pose estimation for front chassis module and dimensional evaluation to find the rotational characteristics of front lower arm were developed based on fundamental geometric techniques. To interpret the inspection data obtained for front chassis module, 3-D best fit method is needed. The best fit method determines the relationship between the nominal design coordinate system and the corresponding feature coordinate system. The least squares method based on singular value decomposition is used in this paper.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.955-959
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• 2010

The statistical analysis module is developed for the part of the new standardized geotechnical database computer program. The purpose of this module is that the geotechnical engineers can optimize the underground construction process of the underdeveloped urban area rehabilitation by this module providing the statistical information for the geotechnical decision making and risk assessment. This module will be modified to offer the statistical information sustainable for the newly adapted geotechnical limit-state design methods.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1574_1575
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• 2009

This paper investigates the reduction of RE(Radiated Emission) noise in a high power LED module circuit using PWM(Pulse Width Module) switching controller circuit. Poorly designed LED lighting module can experience the RE and CE(Conducted Emission) noise problem. This paper propose the reduction of noise source and improvement of EMI filter design in a high power LED lighting module. The experimental and simulation results showed that reduce the RE noise level effectively.