• 한국멀티미디어학회논문지
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• 제23권11호
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• pp.1372-1382
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• 2020

This paper proposes a core technology for a micro river monitoring terminal device suitable for flood monitoring in small rivers and valleys. Our proposed device is basically equipped with a 77GHz radar, gyro and accelerometer sensors. To measure the flow velocity and water level, we proposed a signal processing technique that extracts pure water energy components from the observed Doppler velocity and reflection intensity from the radar. And to determine the stability of the river structure equipped with our device, we constantly monitor the displacement of the measured values of the gyro and accelerometer sensors. Experimental result verified that our method detects pure water energy in various river environments and distinguishes between flow velocity and water level well. And we verified that vibration and position change of structures can be determined through a gyro sensor. In future research, we will work to build a secure digital twin river network by lowering the cost of supplying RF-WAV devices. Also we expect our device to contribute to securing a preventive golden time in rivers.

• 한국전기전자재료학회논문지
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• 제21권1호
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• pp.85-89
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• 2008

An objective of this paper is to develop a partial discharge (PD) measurement device for monitoring gas insulated switches installed in power distribution system. A capacitive voltage probe was studied and designed to detect PD pulse without an electrical connection. The PD measurement device consists of the capacitive voltage probe attached outside of a bushing, a coupling network which attenuates AC voltage by 270 dB, and a low noise amplifier with the gain of 40 dB in ranges of 500 kHz${\sim}$20 MHz. The sensitivity of the prototype device calculated by a calibrator was 1.98 m V /pc. An application experiment was carried out in a 25.8 kV gas insulated switch and the peak pulse of 76.7 pC was detected. From the experimental results, it is expected that the PD measurement device can be applied to online monitoring system of gas insulated switches.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.273-280
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• 2008

Debris flow has been considered as one of the major natural hazards and possesses tens to hundreds times higher destructive potential than that of slope failure. In the past 5 years, its occurrence frequency was and is likely to increasing due to the global warming. Although various methods such as basin vegetation or structural dams can be implemented to counter measure the debris flow, these methods are not always the right answer to the problem when magnitude of debris flow is far bigger than could be defended. Land use regulations to avoid the hazard or early debris flow warning system to evacuate the expected inundated area can be more economical and practical actions for those cases. In this study, an early debris flow warning system composed of rainfall measuring device, debris flow sensing device and video camera is introduced. The system is designed to issue the warning when rainfall threshold is exceeded or debris flow is sensed by sensing device. Developed monitoring system can be used to cope promptly with the debris flow risk.

• Journal of Information Processing Systems
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• 제16권3호
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• pp.733-741
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• 2020

A smart dust monitoring system is useful for obtaining information on rough terrain that is difficult for humans to access. One of ways to deploy sensors to gather information in smart dust environment is to use an aircraft in the Amazon rainforest to scatter an enormous amount of small and cheap sensors (or smart dust devices), or to use an unmanned spacecraft to throw the sensors on the moon's surface. However, scattering an enormous amount of smart dust devices creates the difficulty of managing such devices as they can be scattered into inaccessible areas, and also causes problems such as bottlenecks, device failure, and high/low density of devices. Of the various problems that may occur in the smart dust environment, this paper is focused on solving the bottleneck problem. To address this, we propose and construct a three-layered hierarchical smart dust monitoring system that includes relay dust devices (RDDs). An RDD is a smart dust device with relatively higher computing/communicating power than a normal smart dust device. RDDs play a crucial role in reducing traffic load for the system. To validate the proposed system, we use climate data obtained from authorized portals to compare the system with other systems (i.e., non-hierarchical system and simple hierarchical system). Through this comparison, we determined that the transmission processing time is reduced by 49%-50% compared to other systems, and the maximum number of connectable devices can be increased by 16-32 times without compromising the system's operations.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2002년도 학술발표회 발표논문집
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• pp.137-140
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• 2002

The monitoring system for integrated management of on-site wastewater treatment plants(biofilter) was designed and its operation program was developed. In design process, the research on monitoring parameters which will be able to represent condition and operation of the pilot plants was accomplished, and these parameters came to reveal with ORP(Oxidation-Reduction Potential), water level, pump and power on/off. Proposed monitoring system is composed with measurement, control, communication and display device, and PCB(Prototype Circuit Boards) and microcontroller (PIC16F877) technique are applied to its design of control device for performing specific function. also, The operation program of PC setup is developed in order to provide a convenience to the manager.

• 대한전기학회논문지:전력기술부문A
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• 제53권11호
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• pp.581-588
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• 2004

Power qualify monitoring system is devoted to more concern than before, because the innovation of industrial technology needs more accurate instruments and more advanced power quality. This paper was studied on using data of the protective relay by Power Quality Monitor. This paper was proposed the wave storage condition and monitoring clauses of the protective relay as a power quality monitoring device. The protective relay will have problem to save data for PQM analysis because the protective relay memory is limited. Therefore this paper was proposed new a data compression of data got from the protective relay. This method is wave compression comparison algorithm using the DFT. The compression rate is higher than any other established method. This method can be real time storage. This algorithm is verified using the comparison among other compression rate and proved by Real Time Digital Simulator (RTDS).

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.122-122
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• 2000

Polishing work of a free-curved surface die demands simple and repetitive operations but requires a considerable amount of time for high precision. In out previous study, to reduce the polishing time and solve the problem of the shortage of skilled workers, the automatic polishing system was developed. However, in the polishing process of die, workers have to stay still in factory to monitor the polishing process for a long time in the poor environment. Therefore, this study proposes the remote operation and monitoring system of the automatic polishing robot. The developing system offer worker monitoring functions and teleoperating functions, as following: system state check, manual manipulation mode, automatic mode, manual teaching mode, automatic teaching mode, simulation by virtual manufacturing device. And automatic teaching system is developed to easily obtain a teaching data.

• 한국입자에어로졸학회지
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• 제15권2호
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• pp.67-78
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• 2019

Since existing measurement sites are required to construct a high-cost PM measuring device and a measuring site of a large area, there is a limit to the construction of a high-resolution measurement network. Therefore, it is necessary to develop a low-cost, high-performance PM measuring device (as an alternative technology) that can increase the resolution of PM measurement, and it is necessary to establish a base to provide real-time PM information for whole people. Therefore, in this study, the alternative technique (light scattering method) for achieving the above object was examined, performance evaluation was carried out, and it was verified that the light scattering method was usable. Various PM measurement results were compared and analyzed to find PM monitoring points and resolutions we would like to propose.

• 대한설비관리학회지
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• 제23권4호
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• pp.21-27
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• 2018

This paper proposed the real-time monitoring methodology of a traffic signal controller. The proposed methodology is based on the simulation technology, and it is necessary to construct a simulation model imitating the behavior of a traffic signal controller. By executing the simulation model, we can obtain the 'nominal system trajectory' of the traffic signal controller. On the other hand, an IoT(Internet of Things)-based monitoring device is implemented in a traffic signal controller. Through the monitoring device, it is possible to obtain the 'actual system trajectory'. By comparing the nominal system trajectory and the actual system trajectory, we can estimate the degree of deterioration of a traffic signal controller.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.455-460
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• 2007

A self-sensing circuit for piezo inkjet has been designed in order to monitor the operating condition during printing. In order to verify the circuit, both ink droplet images from strobe LED and vibration signals from the laser vibrometer were measured and compared with self-sensing signal. Experimental results show that self-sensing signal was effective in detecting the pressure wave change due to the bubble trapped in inkjet printhead.