• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.327-327
• /
• 2010

디스플레이 및 반도체 산업이 발전함에 따라 회로의 선폭이 점차 줄어들고 있으며, 이에 따라서 대표적인 오염원이 되는 오염입자의 임계 직경(critical diameter) 또한 작아지고 있다. 현재 반도체 및 디스플레이 산업에서 사용되는 측정방법은 레이저를 이용하여 공정 후 표면에 남아 있는 오염입자를 측정하는 ex-situ 방법이 주를 이루고 있다. Ex-situ 방법을 이용한 오염입자의 제어는 웨이퍼 전체를 측정할 수 없을 뿐만 아니라 실시간 측정이 불가능하기 때문에 공정 모니터링 장비로 사용이 어려우며 오염입자와 공정 간의 상관관계 파악에도 많은 제약이 따르게 된다. 이에 따라 저압에서 in-situ 방법을 이용한 실시간 오염입자 측정 기술 개발이 요구되고 있다. 본 연구에서는 저압 환경에서 실시간으로 입자를 모니터링 할 수 있는 장비를 입자의 광산란 원리를 이용하여 개발하였다. 빛이 입자에 조사되면 크게 산란 및 흡수현상이 일어나게 되는데, 이 때 발생하는 산란광은 입자의 크기와 관계가 있으며 Mie 이론으로 널리 알려져 있다. 현재 이를 이용한 연구가 국내 및 국외에서 진행되고 있다. 수 백 nm 대의 입자를 측정하기 위해서는 빛의 강도가일정 수준 이상 되어야 하며, 이를 측정할 수 있는 수신부의 감도 또한 중요하다. 본 연구에서는 빛의 직경을 100 um 이하까지 집속할 수 있는 광학계를 상용 프로그램을 이용하여 설계하였으며, 강도가 약한 산란광 측정을 위하여 노이즈 제거 필터링 기술 등이 적용된 수신부 센서를 개발하여 전체 시스템에 적용하였다. 교정은 상압과 저압에서 수행 하였으며 약 5%의 측정효율로 최소 300 nm 이하의 입자까지 측정이 가능함을 확인 하였다. 또한, 타사의 실시간 입자 측정 센서와의 비교 실험을 통하여 성능평가를 수행하였다. 기존 광산란 방식 센서보다 높은 성능의 센서를 개발하기 위하여 추후 연구를 진행할 계획이며, 약 200 nm 이하의 입자까지 측정이 가능할 것으로 기대된다.

• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.1
• /
• pp.68.2-68.2
• /
• 2012

한국우주전파관측망(KVN)을 이루는 각 망원경에 22GHz, 43GHz, 86GHz, 129GHz의 4개의 주파수 대역을 동시에 관측할 수 있는 전파 수신시스템을 구축하고 있다. 현재, 22GHz와 43GHz의 수신기가 설치되어 있고, 86GHz와 129GHz 수신기가 2012년 상반기에 설치 완료할 예정이다. 이들 중, 129GHz 수신기의 핵심인 초전도 전파수신소자에 공급하는 바이어스 전원의 공급 시스템을 2년에 걸쳐 설계 및 제작 완료하였다. 개발된 Bias Supply System은 주 보드, User Interface, 전용 정전압 모듈, Protection 모듈 등이 한 Sub-Rack에 결합되어 있다. 먼저, Bias Supply System 시제품 1set를 우선 제작하여 연세전파천문대의 129GHz수신기 초전도 전파수신소자 제어에 설제 적용하였다. 이를 바탕으로, 수정과 보완 및 Remote M&C 기능을 추가하여 새로 설계하고 제작한 최종 Bias Supply System 3set를 개발 완료하였고, 129GHz 수신기 3기의 초전도 전파수신소자 구동에 운용하고 있다. 본 발표에서는 그 개발 내용을 소개하고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2008.05a
• /
• pp.841-844
• /
• 2008

This paper describes technical method about remote control and monitoring of local system by use internet web connection system, which connect local system and system manager works in long distance office. The local system, which will be controlled remotely have constructed with analog/digital signal acquisition device, signal control board and their software. The local systems are constructed with several electronic modules need AC or DC power supply to operate the right way. We used NI labview software to control and monitoring of local system. The computer server for remote connection are constructed with Apache web server, PHP and MySQL ODBC. The experiment for the remote control are need internet web browser which load local control software. By use of web system, we have experimented control and monitoring of local electronic module.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.54 no.4
• /
• pp.35-43
• /
• 2017

In this paper, we propose indoor IoT monitoring system based on visible light communication using smart phone with attracting attentions in recent wireless communication. The main features and contributions of the proposed system developed in this paper are as follows. First, the actual data generated within indoor can be processed via the server by using only the visible light communication. Second, the collected data by using the visible light communication can be monitered by smart phone. Performance evaluation of the proposed system is performed under illumination of the normal fluorescent lamps. We first check successful transmission between transmitting module and receiving module of the data collection system. The monitoring system is tested according to the change of the degree of condensing and distance of the LED and the decoding success rate of the proposed smart phone application. We expect that the proposed system can be applied for indoor and outdoor IoT areas together.

• Journal of the Korea Convergence Society
• /
• v.9 no.10
• /
• pp.61-67
• /
• 2018

This study covers the results obtained after three years of development work of real - time gas safety monitoring app. In order to reduce the risk of accidents in the gas workplace, it is essential to provide information so that operators can recognize the location of dangerous substances, dangerous facilities, safety procedures, and the temperature and humidity of the workplace. Therefore, this study was conducted to develop a monitoring app that allows the main system to efficiently receive the information in the field where the information is continuously updated. As a result of quantitative and qualitative research and analysis on app scenarios based on the research done in the past and web screen of the main system, it was modified and improved in terms of ease of use, readability, and intuitiveness. Especially, we made many improvements at low depth, which is a sub-area of ease of use. As a result of conducting a user satisfaction survey on the finally derived app scenarios, the average score of 98.5 was obtained in terms of functionality, convenience and readability.

• Journal of IKEEE
• /
• v.26 no.3
• /
• pp.396-400
• /
• 2022

In this study, an ICT-based underwater communication monitoring device for underwater structures is implemented based on lifting fixture that transport human bodies found on the seabed to sea level. The lifting fixture is packaged with a retback, sideback, and cartridge that injects air. Monitoring systems are developed in a mobile manner in a portable structure. The underwater ultrasonic sensor signal is supplied using a USB port, and the O/S consists of Linux. For the underwater communication dong test, a measurement test was conducted in real time from 6m to 40m in depth on the east coast. The ultrasonic sound sensor is converted to 2,400 bps to verify the transmission error according to the duality. The communication speed of sensor to monitoring is 115,200 bps, and the speed of communication from controller to receiver is 2,400 bps. In the commercialization stage of the lifting device, it is easy to develop a low-end type and the compatibility is wide.

• Journal of the Korea Society of Computer and Information
• /
• v.27 no.12
• /
• pp.141-149
• /
• 2022

In this paper, we propose a design of CCTV enlcosure record management system based on blockchain. Since CCTV video records are transferred to the control center through enclosure, it is very important to manage the enclosure to prevent modulation and damage of the video records. Recently, a smart enclosure monitoring system with real-time remote monitoring and opening and closing state management functions is used to manage CCTV enclosures, but there is a limitation to securing the safety of CCTV video records. The proposed system detect modulated record and recover the record through hash value comparison by distributed stored record in the blockchain. In addition, the integrity verification API is provided to ensure the integrity of enclosure record received by the management server. In order to verify the effectiveness of the system, the integrity verification accuracy and elapsed time were measured through experiments. As a result, the integrity of enclosure record (accuracy: 100%) was confirmed, and it was confirmed that the elapsed time for verification (average: 73 ms) did not affect monitoring.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.11 no.4
• /
• pp.361-371
• /
• 2009

Resistivity tomography is very effective geophysical method to find out the resistivity distribution and its change in time around a tunnel. Thus, the resistivity tomogram can provide helpful information which is necessary for the effective maintenance of the tunnel. However, an air filled tunnel severely distorts tomography data, especially when the current or potential electrode is placed near the tunnel. Moreover, the distortion can often lead to misinterpretation of tomography monitoring data. To solve these problem, we developed a resistivity modeling and time-lapse inversion program which include a tunnel. In this study, using the developed program we assured that the inversion including a tunnel gives much more accurate image around a tunnel, compared with the conventional tomogram where the tunnel is not included. We also confirmed that the time-lapse inversion of resistivity monitoring data defines well resistivity changed areas around a tunnel in time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.05a
• /
• pp.343-346
• /
• 2012

Today, According to it widely used that third generation mobile networks service, WCDMA module development technology and its utilization is expanding increasingly and thus to IT Convergence industries is a trend that a lot of appears. This paper, OBD-II communications to bring a vehicle information use and data to an external server transfer and it was developed that vehicle status monitoring from other external devices can be system. From the various sensors inside a vehicle using the OBD-II connector read the information, after converting the user easier to see, WCDMA module using the car status monitoring system to transfer to an external data server was implemented. Developed to test the performance of the system using virtual's state vehicle simulator, which occurs in the real car that will generate the data. It was sent to the OBD-II connector to be occurred data, vehicle status monitoring system was confirmed that Data was received without error. In addition, When this data using WCDMA transmit data to an external server the same data was confirmed that it was received without error. In the future, this technology using the OBD-II vehicle IT convergence technology can be used in a wide range.

• Journal of the Institute of Convergence Signal Processing
• /
• v.20 no.1
• /
• pp.16-23
• /
• 2019

Fine particulate matter known as PM 2.5 refers to the atmospheric particulate matter that has a diameter less than 2.5 micrometer identified as dangerous element for human health and its concentration can provide us a clear picture about air dust concentration. Humans stay indoor almost 90% of their life time and also there is no official indoor dust concentration data, so our study is focused on measuring the indoor air quality. Indoor dust data monitoring is very important in hospital environments beside that other places can also be considered for monitoring like classrooms, cements factories, computer server rooms, petrochemical storage etc. In this paper, visible light communication system is proposed by Manchester encoding technique for electromagnetic interference (EMI)-free indoor dust monitoring. Important indoor environment information like dust concentration is transferred by visible light channel in wide range. An average voltage-tracking technique is utilized for robust light detection to eliminate ambient light and low-frequency noise. The incoming light is recognized by a photo diode and are simultaneously processed by a receiver micro-controller. We can monitor indoor air quality in real-time and can take necessary action according to the result.