• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.834-837
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• 2015

본 논문은 0-5 볼트의 범위에서 실시간 아날로그 ECG 신호를 생성하는 FPGA 하드웨어 기반 ECG 시뮬레이터를 설계하고 기능 및 특성을 기술하였다. 시뮬레이터에 의해 생성된 ECG 신호는 실험실 실험, 의료 기기 교정 및 연구에 사용되거나 다양하게 응용할 수 있다. 시뮬레이터의 ECG 신호는 신호 데이터를 생성하기 위하여 기존의 24bit 양자화로 획득한 후 실 데이터로 사용할 때에는 1kHz의 샘플링과 8비트로 분해, 양자화 되었다. 제안 시뮬레이터는 xilix Spartan-3를 이용하여 구현하였으며 PC와 설계 FPGA 시뮬레이터 간에 RS-232를 통하여 데이터를 전송할 수 있도록 하였다. 전송된 데이터는 메모리에 저장하고 저장된 데이터는 DAC(0808) 통하여 아날로그 ECG 신호로 출력되게 하였다. 또한 두 개의 버튼 수위를 통하여 심박수(HR)를 UP-DOWN할 수 있도록 하였다. 설계된 시스템의 평가를 위하여 기존의 심전도 입력을 사용하여 출력신호와 QRS파형의 획득을 위한 미분회로 통과 결과를 평가한 결과 적합한 결과를 얻을 수 있었다.

• Journal of Power Electronics
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• 제14권3호
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• pp.444-457
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• 2014

This paper presents the design and realization of a digital PV simulator with a Push-Pull Forward (PPF) circuit based on the principle of modular hardware and configurable software. A PPF circuit is chosen as the main circuit to restrain the magnetic biasing of the core for a DC-DC converter and to reduce the spike of the turn-off voltage across every switch. Control and I/O interface based on a personal computer (PC) and multifunction data acquisition card, can conveniently achieve the data acquisition and configuration of the control algorithm and interface due to the abundant software resources of computers. In addition, the control program developed in Matlab/Simulink can conveniently construct and adjust both the models and parameters. It can also run in real-time under the external mode of Simulink by loading the modules of the Real-Time Windows Target. The mathematic models of the Push-Pull Forward circuit and the digital PV simulator are established in this paper by the state-space averaging method. The pole-zero cancellation technique is employed and then its controller parameters are systematically designed based on the performance analysis of the root loci of the closed current loop with $k_i$ and $R_L$ as variables. A fuzzy PI controller based on the Takagi-Sugeno fuzzy model is applied to regulate the controller parameters self-adaptively according to the change of $R_L$ and the operating point of the PV simulator to match the controller parameters with $R_L$. The stationary and dynamic performances of the PV simulator are tested by experiments, and the experimental results show that the PV simulator has the merits of a wide effective working range, high steady-state accuracy and good dynamic performances.

• Journal of Power Electronics
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• 제15권4호
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• pp.1018-1025
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• 2015

This paper proposes a methodological scheme for the photovoltaic (PV) simulator design. With the advantages of a digital controller system, linear interpolation is proposed for precise fitting with higher computational efficiency. A novel control strategy that directly tackles two different duty cycles is proposed and implemented to achieve a full-range operation including short circuit (SC) and open circuit (OC) conditions. Systematic design procedures for both hardware and algorithm are explained, and a prototype is built. Experimental results confirm an accurate steady state performance under different load conditions, including SC and OC. This low power apparatus can be adopted for PV education and research with a limited budget.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 추계학술대회 논문집
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• pp.259-266
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• 1999

A study on the static type train simulator will include the training of new drives requires that the environment of the cab, controls placement, etc. must highly realistic so that driver can readily transfer his training experience to the real world. The simulator computer sends video disc speed command to a Video PC processor. A video switcher select the output of the on-line player. This selection is done with loss of vertical synchronization, meaning the picture will not noticeable roll or jump as the simulation mover from disc to disc. The video image quality remain contestant through the simulated speed range from zero to 100km/h. Flicker is avoided in the scene by the use of a TBC(Time Base Corrector) which causes the display of one video field at a time. Thus, no interfield jitter is present when the scene is stopped.

• 융합신호처리학회 학술대회논문집
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• 한국신호처리시스템학회 2000년도 하계종합학술대회논문집
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• pp.333-336
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• 2000

In this paper, a profile management system consisting of global and local range finders is presented for the automat ion of material pile handling. A global range finder detects range data of the front part of the piles of material and a profile map is obtained from a 3D profile detection algorithm. A local range finder attached on the side of the arm of the reclaimer detects range data with the handling function dynamically, and a local profile patch is acquired from the range data A yard profile map manager constructs a map by using the 3D profile of the global range finder and revises the map by replacing it with the local profile patch obtained Iron the local range finder. The developed vision system was applied to a simulator and the results of test show that it is appropriate to use for automating the material handling.

• 전자공학회논문지
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• 제54권5호
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• pp.90-96
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• 2017

낮은 비용으로 넓은 관측 범위를 갖는다는 장점으로 최근 해양 감시 시스템 개발을 위해 HF 레이더를 이용한 선박 검출 및 추적 연구가 수행되고 있다. HF 레이더를 이용한 해양 감시를 위해 수많은 선박 관측과 추적 알고리즘이 개발되었지만, 각 연구에 사용된 데이터는 선박의 이동 경로와 크기 등 대상 선박에 대한 조건이 다르기 때문에 동등한 조건에서 그 성능을 비교할 수 없다. 본 논문에서는 선박 크기와 이동 경로에 따른 데이터를 생성할 수 있는 콤팩트 HF 레이더 기반 데이터 생성 시뮬레이터를 제안한다. 이를 통해 생성된 데이터를 이용하면 동일한 선박 조건에서 성능 비교가 가능할 것이다. 실험에서는 제안하는 시뮬레이터에서 생성된 데이터와 SeaSonde HF 레이더 사이트에서 실제 관측된 데이터를 비교하였다. 비교 결과, 제안하는 시뮬레이터를 사용하여 생성된 데이터와 실제 환경에서 획득된 데이터가 유사함을 확인할 수 있었다. 그러므로 선박의 크기 및 이동 경로에 따라 생성된 시뮬레이션 데이터를 사용함으로써, 알고리즘의 검출 및 추적 성능을 각각 비교, 분석 할 수 있을 것이다.

• 한국음향학회지
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• 제37권6호
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• pp.451-456
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• 2018

최근 장거리 수중음향통신 연구가 활발하게 진행되고 있다. 장거리 수중음향통신 연구를 위한 해상실험은 해양환경의 영향을 크게 받고 높은 비용과 많은 시간이 소요된다. 따라서 장거리 환경에서 수중음향통신 시스템의 성능을 예측하고 검증하기 위한 시뮬레이터에 대한 연구가 필요하다. 본 논문에서는 장거리 수중음향통신 시뮬레이터의 개발을 목적으로 중장거리 다중송신환경에서 수중음향통신 시뮬레이터로서 VirTEX(Virtual Time series EXperiment)의 성능을 분석하고, 해상 실험 결과와 비교 검증하였다. 송신 신호는 탐침을 위한 Chirp신호와 16QAM 방식으로 변조된 통신 신호를 사용하였다. VirTEX를 통해 수신 신호를 모의하고 다중송신환경에 의해 발생하는 채널 간 간섭을 적응 수동형 시역전을 이용하여 보상하여 통신 성능을 분석하였다. 또한 2005년 7월 이탈리아의 Elba island 북쪽 해역에서 수행한 FAF05(Focused Acoustic Field 2005) 실험 데이터와 비교하여 이를 검증하였다.

• 한국정보통신학회논문지
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• 제3권4호
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• pp.819-830
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• 1999

NAVTEX system is an international automated direct-printing service, broadcast on 5181kHz and 490kHz, for the promulgation of navigational and meteorological warnings and urgent information to ships. With our government's adoption of the international convention for SAR(Search and Rescue) in 1993, various trials for the installation of NAVTEX system have been executed by the government committee, relating laboratory and experts. An important consideration of the installation for NAVTEX system is the availability that could broadcast messages written in korean letter. Also, the receiver which can process the signal demodulated from the two frequencies, 518kHz and 490kHz, should be developed and supplied in domestic. In this paper, the code table and algorithm for conversions between NAVTEX characters and Korean Letters are studied, and signal processing techniques of code conversion are developed. Circuit design and implementation of the NAVTEX simulator using the Direct Digital Synthesizer are discussed, code conversion algorithm and signal processing technique of the NAVTEX transmission are programmed in its circuits. For evaluating the its functional characteristics, receiving module which has I-Q channel structure is designed. From the measurements of simulator, the characteristics show the frequency stability of the $(\pm)2Hz$ and Spurious free dynamic range is -63dBc. And the simulator can generate simultaneously wanted signal and several interfere signals. So, its capability is valuable for designers of the transmitting system and NAVTEX receiver, for provider as testing facilities of the type approval.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.216-221
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• 2003

A thermal vacuum chamber is mainly used to simulate thermal environments of a test satellite in satellite orbits in which daily temperature variations range from 80K to above 400K depending on solar radiation under the vacuum below $10^{-4}$ torr. The test facility is quite complex and consists of expensive parts. So any modification of control software is discouraged in fear of unexpected system failure. The purpose of this study is to develop a realtime dynamics model of the thermal vacuum chamber in view of controller design and simulate its electrical inputs and outputs for interface with a PLC (programmable logic controller). A PLC program that was used in the thermal vacuum chamber is applied to the realtime simulator. The realized simulator dynamics is found to be quite similar to that of the thermal vacuum chamber and serve to an appropriate plant to verify the control performance of a programmed PLC.

• 대기
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• 제24권2호
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• pp.173-188
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• 2014

The KMA has cooperated with the Oklahoma University in USA to develop a Polarimetric Radar Data (PRD) simulator to improve the microphysical processes in Korea Local Analysis and Prediction System (KLAPS), which is critical for the utilization of PRD into Numerical Weather Prediction (NWP) field. The simulator is like a tool to convert NWP data into PRD, so it enables us to compare NWP data with PRD directly. The simulator can simulate polarimetric radar variables such as reflectivity (Z), differential reflectivity ($Z_{DR}$), specific differential phase ($K_{DP}$), and cross-correlation coefficient (${\rho}_{hv}$) with input of the Drop Size Distribution (DSD) and scattering calculation of the hydrometeors. However, the simulator is being developed based on the foreign observation data, therefore the PRD simulator development reflecting rainfall characteristics of Korea is needed. This study analyzed a potential application of the 2-Dimension Video Disdrometer (2DVD) data by calculating the raindrop axis ratio according to the rain-types to reflect Korea's rainfall characteristics into scattering module in the simulator. The 2DVD instrument measures the precipitation DSD including the fall velocity and the shape of individual raindrops. We calculated raindrop axis ratio for stratiform, convective and mixed rainfall cases after checking the accuracy of 2DVD data, which usually represent the scattering characteristics of precipitation. The raindrop axis ratio obtained from 2DVD data are compared with those from foreign database in the simulator. The calculated the dual-polarimetric radar variables from the simulator using the obtained raindrop axis ratio are also compared with in situ dual-polarimetric observation data at Bislsan (BSL). 2DVD observation data show high accuracies in the range of 0.7~4.8% compared with in situ rain gauge data which represents 2DVD data are sufficient for the use to simulator. There are small differences of axis ratio in the diameter below 1~2 mm and above 4~5 mm, which are more obvious for bigger raindrops especially for a strong convective rainfall case. These differences of raindrop axis ratio between domestic and foreign rainfall data base suggest that the potential use of disdrometer observation can develop of a PRD simulated suitable to the Korea precipitation system.