• Journal of Radiation Protection and Research
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• v.28 no.3
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• pp.255-261
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• 2003

An environmental radiation monitoring system based on high pressurized ionization chamber has been used for on-line gamma monitoring surrounding the KAERI (Korea Atomic Energy Research Institute), which transmits the dose data measured from ion chamber on the site via radio frequency to a central processing computer and stores the transmitted real-time data. Although communication using radio frequency has several advantages such as effective and economical transmission, storage, and data process, there is one main disadvantage that data loss during transmission often happens because of unexpected communication problems. It is possible to restore the loss data by off-line such as floppy disk but the simultaneous process and display of current data as well as the backup data are very difficult in the present on-line system. In this work, a new electronic circuit board and the operation software applicable to the conventional environmental radiation monitoring system are developed and the automatical synchronization of the ion chamber unit and the central processing computer is carried out every day. This system is automatically able to restore the backup data within 34 hours without additional equipments and also display together the current data as well as the transmitted backup data after checking time flag.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.05a
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• pp.200-203
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• 2001

감성평가 실험시 피험자가 받는 작업부하의 영향을 실시간으로 평가하기 위하여 측정된 심전도 신호로부터 R-peak를 자동적으로 검출하여 심전도 관련 파리미터를 분석하는 시스템을 개발하였다. 이 시스템은 심전도 증폭기, A/D변환기, PC로 구성되었으며 National Instrument 사의 LabVIEW를 사용하여 소프트웨어를 개발하였다. 시스템 동작환경은 Microsoft사의 Window OS를 기반함으로서 시스템 이용자들에게 보다 친숙한 실험환경을 제시할 수 있다. 구현된 시스템은 실시간 HRV, Lorentz plot, LF/HF, HRV power spectrum의 3차원 선도를 디스플레이할 수 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 1989.07a
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• pp.89-94
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• 1989

본 연구는 하천 수질의 종합관리를 위한 sotware 시스템과 hardware 시스템을 개발하는 것이다. Software 시스템은 하천의 오염실태 조사분석 자료를 활용하여 예측모형의 반응식과 제 계수를 도출하고, 수질변동 및 예측모형의 중요지표 수질인자들에 대한 시각적 화면 display 를 위한 그래픽 모듈과 우리나라 오염심화 하천에 알맞는 종합수질 관리용 컴퓨터 프로그램을 개발하므로서 궁극적으로 하천의 한정된 수자원의 최적 활용을 위한 정량적, 정성적 종합수질 관리 시스템을 개발하는 것이다. 또한, Hardware 시스템은 지표 수질인자들을 자동 측정하여 on line, real time 으로 운영 될수 있는 computer supported monitoring network system 과 수질관리를 위한 지역적 수질정보를 위한 network system 을 연구하므로서 control computer system 및 programmable process controllers system 을 구축하고자 한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2009.01a
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• pp.255-258
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• 2009

본 논문은 USN시스템을 이용해서 실시간으로 병원의 각 병실에 대한 센서에서 측정된 정보를 관리자에게 실시간으로 모니터링 할 수 있도록 해주며 노드의 설정이나 프로그램 전송을 다른 프로그램을 사용하지 않고도 센서에 전송할 수 있게 한다. 또한 이 시스템에서는 단순한 모니터링뿐만 아니라 제어장비를 통해서 환경을 자동으로 제어할 수 있도록 하는 일체형 시스템 구축을 목표로 한다. 본 논문에서는 제안한 시스템과 기존의 병원 시스템과 비교해 보았다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.625-626
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• 2017

장시간 앉아 생활을 하는 직장인이나 학생들은 시간 경과에 따른 집중력 저하는 필수적으로 동반되며, 이를 모니터링하여 집중력을 향상시키기 위한 다양한 시도들이 연구되고 있다. 본 연구에서는 간편하게 착용이 가능한 무선뇌파계측 시스템기반이 실시간 집중력 모니터링 시스템을 구현하고자 하였으며, 이를 위하여 블루투스기반의 무선뇌파 측정시스템과 스마트폰 기반의 뇌파분석 어플리케이션을 개발하였다. 어플리케이션에서는 실시간 스펙트럼분석을 통해 집중력 파라미터를 추출하고 집중력의 저하를 인지하면 자동으로 피드백할 수 있도록 시스템을 구성하였다. 구현된 시스템의 평가를 위해 집중상태를 유발하고 각각의 상태별 뇌파스펙트럼 파라미터의 상관관계를 분석하였으며, 실험결과 본 연구에서 제시한 기법을 통해 실시간 집중상태 모니터링이 가능함을 확인하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.8
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• pp.1051-1057
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• 2013

In this study, an automatic surface-strain measurement system called "ASIAS-bio" has been developed. This system can be used even in cases in which it is very difficult to apply a regular grid pattern necessary for measuring surface-strain, such as curved or uneven surfaces; surfaces damaged by corrosion or contamination; or soft materials such as rubber, foam, and biological tissues. This system works independently of the measurement conditions including the material and its surface condition, grid pattern and size, grid marking method, and degree of deformation. A comparison between the strain distributions of the sheet metal parts measured by using this system and those obtained by a commercial system showed that this system was sufficiently reliable. In addition, the deformation of the swine joint capsule and human knee skin was measured by using this system to demonstrate its usefulness.

• Journal of The Korean Society of Grassland and Forage Science
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• v.41 no.4
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• pp.295-301
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• 2021

In this study we developed the ground-based multispectral camera system to determine proper period to build and apply the calibration equation for dry matter of winter forage corps monitoring by unmanned aerial vehicle (UAV). Normalized difference vegetation index (NDVI) of rye, whole barley and Italian ryegrass (IRG) were measured and the growth period was divide by NDVI increasing period and decreasing period. Day of the maximum NDVI value of rye, whole barley and IRG were 8th, 9th and 5th April 2020. Regression analysis showed that the correlation coefficients (R²) between dry matter and NDVI were 0.84, 0.84, 0.78 during NDVI increasing period and 0.00, 0.02, 0.27 during NDVI decreasing period. Therefore, detailed NDVI monitoring is required to determine the proper period to build and apply the calibration equation and the ground-based multispectral camera system was effective tool for detailed NDVI monitoring.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.12
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• pp.987-995
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• 2020

Accurate alignment between high-performance payloads and attitude control sensors is essential factor to guarantee accurate attitude orientation and high pointing stability of the satellite. Space craft developers often use theodolite measurement system for satellite alignment during ground AIT(Assembly Integration and Test) phase. When measuring theodolite, errors may occur due to line of sight error, tilting axis error, vertical index error, and vertical axis error. In addition, errors that can occur during alignment measurements with multiple theodolites are analyzed through the alignment cube measurements test. Based on the alignment cube measurements test, a technical method that can improve the alignment measurement accuracy was suggested and it's measurements results satisfied the satellite design requirements.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.5
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• pp.1038-1044
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• 2011

In this paper, the multichannel intermediate frequency transceiver for broadband multimedia system is designed and the experimental results are analyzed. Basic elements of the transceiver such as frequency synthesizer, amplifier, mixer, automatic gain control amplifier are introduced. The analysis technique described here applies not only to amplifier but also to any other nonlinear components such as mixers and frequency doubler. Through the investigation of the power spectrum density of the transmitted signal, the phase noise of the local oscillator is evaluated below 70 dBc/kHz. The frequency characteristics of the modulated signal is flat within the system bandwidth. Also the effects of adjacent channel interference and supurious emission are analyzed. And the function of automatic gain control amplifier is well operated.

• Journal of Advanced Navigation Technology
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• v.25 no.6
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• pp.523-529
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• 2021

This paper shows the design and fabrication of antenna embedded in marine buoy for marine IoT service, especially automatic identification system of fishing gears. Frequency band of proposed antenna has dual band of 433 MHz and 920 MHz considering marine IoT extension. Dual pattern monopole type for 920 MHz and meander type for 433 MHz are adopted in the proposed antenna. Voltage standing wave ratio is obtained 1.548 at 433 MHz and obtained 1.5 of mean value at 920 MHz band by measuring the fabricated antenna. The maximum antenna gain of 3.83 dBi is measured at 902 MHz among 920 MHz band, while antenna gain of 433 MHz is obtained 1.18 dBi. Although antenna gain of 433 MHz is low than 920 MHz band, this gain is larger than desired value of -5 dBi. And, it is confirmed that other measured values meet the performance criteria for archiving communication distance of 10 km between marine buoy and fishing ship in automatic identification system of fishing gears.