• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.2
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• pp.217-221
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• 2012

As a part of basic research to improve screen quality, which deteriorates when strain occurs within optical sheets in LCD modules for laptop computers, a measurement system is needed to analyze the influence of heat and moisture, which are the main factors causing the strain. It is assumed that the existence of an air gap less of than 0.5 mm inside the LCD module causes humid air from outside to permeate through the module. To investigate this phenomenon, in this study a thin printed circuit board (PCB) of compact sensors that measure temperature and humidity is inserted into LCD modules, and thus, the changes in temperature and humidity can be analyzed in real time. The results can be used as basic data for simulation of the deformation behavior and structural design of LCD modules in the future.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.899-904
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• 2022

As the world becomes an aging society due to a decrease in the birth rate and an increase in life expectancy, a system for health management of the elderly population is needed. Among them, various studies on occupancy and activity types are being conducted for smart home care services for indoor health management. In this paper, we propose a random forest model that classifies activity type as well as occupancy status through indoor temperature and humidity, CO2, fine dust values and UWB radar positioning for smart home care service. The experiment measures indoor environment and occupant positioning data at 2-second intervals using three sensors that measure indoor temperature and humidity, CO2, and fine dust and two UWB radars. The measured data is divided into 80% training set data and 20% test set data after correcting outliers and missing values, and the random forest model is applied to evaluate the list of important variables, accuracy, sensitivity, and specificity.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.1191-1202
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• 2013

The former researches on earthwork automation were mainly focused on GPS and sensor application, environment modelling, equipment path planning, work information management, and remote control etc. Recently, reducing $CO_2$ emission becomes one of main focuses for an automation research. In the case of earthwork operations, many kinds of construction machines or robots are involved, which can cause high level of $CO_2$ in a construction site. An effective earthwork plan and construction machine operation can both increase productivity and safety and decrease $CO_2$ emission level. In this research, some automation concepts for green earthworks are suggested such as a 3D construction site model, a 3D earthwork distribution based on two different earthwork methods, and an earthwork package construction method. A excel-based simulator is developed to generate the 3D earthwork distribution and to estimate the level of $CO_2$ emission for the given earthwork.

• Journal of IKEEE
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• v.27 no.3
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• pp.225-233
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• 2023

This paper implements a system that monitors human body lifting information in the event of a marine accident. The monitoring system performs ultrasonic communication through a lifting device controller that transmits underwater environment information, and LoRa communication is performed on the water to provide GPS information within 10 km to the control center or mother ship. The underwater lifting controller transmits pneumatic sensor, gyro sensor, and temperature sensor information. In an environment where the underwater conditions increase by one atmosphere of water pressure every 10m in depth, and the amount of air in the instrument decreases by half compared to land, a model of a 60kg underwater mannequin is used. Using one 38g CO2 cartridge in the lifting appliance SMB(Surface Maker Buoy), carry out a lifting appliance discharge test based on the water level rise conditions within 10 sec. Underwater communication constitutes a data transmission environment using a 2,400-bps ultrasonic sensor from a depth of 40m to 100m. The monitoring signal aims to ensure the safety and safe human structure of the salvage worker by providing water depth, water temperature, and directional angle to rescue workers on the surface of the water.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.569-574
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• 2014

We developed and evaluated a fluorescence-based optical DO sensor (OS-100, Global Optical Communication Ltd., Korea) for long-term monitoring of the dissolved oxygen concentration in waste water treatment. Fluorescent sensing membrane containing $Ru(Dpp)_3{^{2+}}$ (tris(4,7diphenyl-1, 10-phenanthroline) ruthenium(II)) was prepared with GA sol-gel matrix and coated on a quartz plate by sprayed method. Properties of sensor film exhibit deviation about ${\pm}1%$ under wide range of DO concentration from 3 to 10. The developed optical DO sensor was actually mounted in waste water from dyeing industry and successfully applied for on-line DO monitoring. Online monitoring results showed the changes of DO concentrations in wastewater treatment processes with accuracy better than ${\pm}2%$ during the 6 months measurements period in vicious environmental conditions.

• Journal of the Korean Ceramic Society
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• v.36 no.3
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• pp.237-243
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• 1999

스크린 프린팅법을 이용하여 NOX 감지용 WO3 후막형 가스센서를 제조하였다. 본 실험에서는 감지막의 소성 온도에따른 감도변화 및 Ru을 첨가함으로써 감도의 증진을 중점적으로 조사하였다. 또한 NO2 50 ppm하에서 CO, H2, CH4 그리고 i-C4H10등의 가스에 대하여 cross sensitivity를 조사하였다. WO3 가스센서는 소성온도 50$0^{\circ}C$, 작동온도 30$0^{\circ}C$에서 최대감도를 얻었다. 순수한 WO3에 Ru(0.004 wt%)을 첨가시 NO2 및 NO 가스에 대한 감도가 크게 증진되었다. 그러나 순수한 WO3 센서는 Ru(0.004 wt%)이 첨가된 WO3 센서보다 더 우수한 cross sensitivity를 보였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1506-1514
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• 2015

In this paper, we proposed a forest fires prediction and detection system. It could provide a situation of fire prediction and detection methods using context awareness sensor. A fire occurs wide range of sensing a fire in a single camera sensor, it is difficult to detect the occurrence of a fire. In this paper, we propose an algorithm for real-time by using a temperature sensor, humidity, Co2, the flame presence information acquired and comparing the data based on multiple conditions, analyze and determine the weighting according to fire in complex situations. In addition, it is possible to differential management of intensive fire detection and prediction for required dividing the state of fire zone. Therefore we propose an algorithm to determine the prediction and detection from the fire parameters as an temperature, humidity, Co2 and the flame in real-time by using a context awareness sensor and also suggest algorithm that provide the path of fire diffusion and service the secure safety zone prediction.

• Applied Chemistry for Engineering
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• v.25 no.2
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• pp.193-197
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• 2014

The electrode for gas sensor was prepared by using pitch-based activated carbon fibers and polyvinyl alcohol (PVA) to investigate the toxic gas sensing characteristics. The physicochemical properties of activated carbon fibers electrode for gas sensor were analyzed with SEM and BET. Toxic gases sensing property of the electrode was also identified by different toxic gases such as $NH_3$, NO and $CO_2$. The specific surface area of activated carbon fibers electrode for gas sensor was decreased by 33% owing to PVA used as a binder compared with the activated carbon fibers. However, its pore size distribution of the ACF electrode was not greatly influenced by PVA. The activated carbon fibers electrode for gas sensor responded to toxic gases by electron hopping unlike semiconductor based gas sensors. In this study, activated carbon fibers electrode was decreased to 7.5% in resistance for the NH3 gas of the 100 ppm concentration and its $NH_3$ gas sensing property was confirmed the most excellent compared with other toxic gases.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.425-426
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• 2023

지난 5년 (2016~2020년) 간 고속도로 교통사고 사망자 1,035명 중 약 70%(722명)가 졸음 및 주시 태만으로 인해 발생하였다. 졸음운전 사고를 예방하기 위해 졸음 쉼터나 휴게소 등이 있지만 활용률이 높은 편은 아니다. 해당 문제 해결을 위해 본 논문에서는 자동차 내부에서 즉각적으로 졸음을 판별해 알람을 제공하는 알람 기능을 구현하였다. 차량에 웹캠과 CO₂ 농도 측정기를 설치하여 웹캠으로는 운전자의 눈 종횡비를 계산하여 졸음을 판단하고 CO₂ 센서로 차량 내부 CO₂ 농도를 측정하여 운전자의 졸음을 판단하여 경고음과 음성 경고 메시지를 출력함과 동시에 창문 개폐 기능으로 잠을 깨워주기 때문에 교통사고 발생률 저하에 기여할 것으로 기대된다.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.551-558
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• 2021

In this paper, we made the integrated intelligent air ventilation of the actuator module that can be remotely controlled based on IoT and sensors. we implemented a ventilation window system by configuring an algorithm design and a driving circuit to control the operation of the actuator to open and close the ventilation port based on a predetermined number of data that detects indoor gas/CO2/humidity temperature and outdoor fine dust related indoor/outdoor environment. It is difficult to store, manage, and analyze data due to the large number of sensors and conditions for the transmission data of indoor air circulation module. The remote monitoring and remote wireless control screens were constructed to automate the separation and operation conditions by extracting and managing the state. We apply MQTT to enhance big data transmission and construct the system using Rocket MQ to ensure safe transmission of operational big data against system errors.