• 한국CDE학회논문집
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• 제19권1호
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• pp.68-79
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• 2014

Human model simulation has been widely used in various industrial areas such as ergonomic design, product evaluation and characteristic analysis of work-related musculoskeletal disorders. However, the process of building digital human models and capturing their behaviors requires many costly and time-consuming fabrication iterations. To overcome the limitations of this expensive and time-consuming process, many studies have recently presented a markerless motion capture approach that reconstructs the time-varying skeletal motions from optical devices. However, the drawback of the markerless motion capture approach is that the phenomenon of occlusion of motion data occurs in real-time human simulation. In this study, we propose a systematic method of discriminating missing or inaccurate motion data due to motion occlusion and interpolating a sequence of motion frames captured by a markerless depth camera.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 추계학술대회
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• pp.204-206
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• 2022

스마트 팩토리(Smart Factory) 고도화의 핵심으로 평가되는 디지털 트윈(Digital Twin)은 현실 세계의 자산과 동일한 속성 및 기능을 가지는 디지털 복제본을 가상의 세계에 구현하는 기술이다. 디지털 트윈 기술이 적용된 스마트팩토리는 생산공정의 실시간 모니터링, 생산공정 시뮬레이션, 생산설비 예지보전 등의 서비스를 지원할 수 있어 생산비용 절감 및 생산성 향상에 기여할 것으로 기대된다. AAS(Asset Administration Shell)는 디지털 트윈을 구현하기 위한 필수 기술로, 현실의 물리적 자산을 디지털로 표현하는 방법을 제공한다. 본 논문에서는 스마트팩토리 내 생산설비를 자산으로 간주하여, 운용 중인 실시간 CNC(Computer Numerical Control) 모니터링 시스템에서 활용할 제조 데이터 수집을 위한 AAS를 설계하였다.

• Design & Manufacturing
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• 제17권3호
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• pp.1-7
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• 2023

Blow molding is a manufacturing process in which thermoplastic preforms are preheated and then pneumatically expanded within a mold to produce hollow products of various shapes. The two-step process, a type of blow molding method, requires the output of multiple infrared lamps to be adjusted individually, so the process of finding initial conditions hinders productivity. In this study, digital twin technology was applied to solve this problem. A blow molding simulation technique was established and simulation-based metadata was generated. A response surface ROM (Reduced Order Model) was built using the generated metadata. Then, a dynamic ROM was constructed using the results of 3D heat transfer analysis. Through this, users can quickly check the product wall thickness uniformity according to changes in the control value of the heating lamp for products of various shapes, and at the same time, check the temperature distribution of the preform in real time.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1473-1479
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• 2009

Recently, the high speed train was operated and then the train system's reliability requirements are growing more and more. The exact prediction simulation is necessary in the design of power feeding system by the increase of railway electrification. In order to develope the AC feeding system analysis technology, real-time power simulator was manufactured. It is composed to eight channels analog input, forty channels analog output and forty-eight channels digital I/O. The size of simulator rack is 19" and the two I/O boards are installed the PXI chassis built into the real time os. The signal I/O is possible through BNC connector. The test results of manufactured simulator are obtained that the error range of analog I/O signal is below 1 % and simulation condition is set to 1 ms and the simulation output of the analog output compares the results of the simulator.

• 대한전자공학회논문지
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• 제23권4호
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• pp.429-438
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• 1986

In this paper we have designed and implemented a real-time, full-duplex SBC (sub-band coding) codec at 16kbps using a high speed digital signal processor, NEC 7720. The SBC codec employs a QMF(quadrature mirror filter) filter bank based on the tree structures of two-band analysis-synthesis pairs to partition speech signal into 4 octabe bands. Computer simulation has been done to investigate the effect of fixed-point computation of the NEC 7720. Three different performance measures, the conventional signal-to-noise ratio, the informal listening test, and an LPC(linear predictive coding)distance measure, have been used in this simulation. The necessary parameters have been optimized through the simulation. The developed hardware and software have been tested in real-time operation using a hardware emulator.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.190-191
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• 2007

This paper proposes a novel simulation method of grid connected 3MW wind power generation system using RTDS(Real Time Digital Simulator). RTDS can perform the simulation as well as the experiment in real time. Also for the purpose of accurate simulation, real wind velocity is measured by anemometer. So measured wind velocity is applied to the simulation. And 3MW wind power generation system circuit is made by RSCAD.

• 방송공학회논문지
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• 제26권4호
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• pp.356-367
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• 2021

최근 사물인터넷 및 인공지능 기술의 발전에 따라 제조, 스마트시티 등 다양한 분야에서 실시간으로 데이터를 수집하고 분석하여 현실세계 문제에 대한 최적화를 수행하는 연구 및 적용사례가 증가하고 있다. 대표적으로 현실세계를 디지털화한 가상세계와 양방향으로 실시간 동기화를 지원하는 디지털 트윈 기술이 주목받고 있다. 본 논문에서는 디지털 트윈을 정의하고 사물인터넷 국제표준인 oneM2M 기반의 IoT 플랫폼을 활용하여 현실사물과 가상세계의 예측결과를 실시간으로 연결하는 디지털 트윈 플랫폼의 프로토타입을 제안한다. 또한, 제안된 프로토타입을 적용하여 물체의 충돌을 사전에 예측하여 사고를 예방할 수 있는 응용서비스를 구현한다. 응용서비스에서는 사전 정의한 테스트 케이스 수행을 통해 제안한 디지털 트윈 프로토타입이 크레인의 동작을 사전 예측하여 충돌 위험을 감지하고 이를 기반으로 최적 제어를 수행할 수 있으며 실제 환경에 응용 가능함을 보였다.

• 대한전기학회논문지
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• 제41권3호
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• pp.281-291
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• 1992

This paper deals with the digital autopilot implementation for a launch vehicle. We propose a hardware and software system for digital autopilot implemented by microprocessor. The hardware system designed in this paper consists of CPU and memory board with 80286 MPU and 80287 NPU and I/O interface with A/D and D/A converters. The software system developed is composed of power-on self-test program, initializing program, interrupt service program, and control program. The performance of the overall system controlled by the digital autopilot implemented in this paper is evaluated via real-time simulations, which show that the control performances are satisfactory.

• 디지털산업정보학회논문지
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• 제8권1호
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• pp.1-7
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• 2012

In this paper Vehicle driving simulator have been used in the development and modification of models. A real-time simulation system and washout algorithm for an excavator have been developed for a driving simulator with six degrees of freedom. An interesting question, "how the 6 DOF Driving Simulator can be controlled optimally for the various tasks?" is not easy to be answered. This paper presents the hardware and software developed for a driving simulator of construction vehicle. A simulator can reduce cost and time a variety of driving simulations in the laboratory. Using its 6 DOF Simulator can move in various modes, and perform dexterous tasks. Driving simulators have begun to proliferate in the automotive industry and the associated research community. This effort involves the real-time dynamic of wheel-type excavator the design and manufacturing of the Stewart platform an integrated control system of the platform and three-dimensional graphic modeling of the driving environments.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.154-161
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• 1999

This paper presents a new approach to the design of adaptive control system using DSPs(TMS320C30) for robotic manipulators to achieve trajectory tracking by the joint angles. Digital signal processors are used in implementing real time adaptive control algorithms to provide an enhanced motion control for robotic manipulators. In the proposed control scheme, adaptation laws are derived from the improved Lyapunov second stability analysis method based on the adaptive model reference control theory. The adaptive controller consists of an adaptive feedforward controller, feedback controller, and PID type time-varying auxillary control elements. The proposed adaptive control scheme is simple in structure, fast in computation, and suitable for implementation of real-time control. Moreover, this scheme does not require an accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the adaptive controller is illustrated by simulation and experimental results for a SCARA robot.