• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.5
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• pp.1017-1022
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• 2018

In this paper, a single house fire alarm device, which can solve the problem of fire perception at midnight time and the attenuation of alarm signal due to the wall between rooms based on the wireless communication, was developed. The radio controlled fire alarm device was designed to allow fire to be recognized quickly and accurately by monitoring the temperature and $CO_2$ concentration based on the temperature sensor and gas sensor, by detecting the fire in the house and by transmitting the fire alarm to the individual wireless alarms of other rooms using the wireless transmission/reception module. Using the Arduino as a main control device, three independent fire alarm device prototypes were made, and their usefulness was verified by the correct operations in temperature and gas tests.

• The Transactions of the Korea Information Processing Society
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• v.13 no.9
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• pp.444-452
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• 2024

This study proposes a deep learning architecture optimized for fire detection derived through Layer Importance Evaluation. In order to solve the problem of unnecessary complexity and operation of the existing Convolutional Neural Network (CNN)-based fire detection system, the operation of the inner layer of the model based on the weight and activation values was analyzed through the Layer Importance Evaluation technique, the layer with a high contribution to fire detection was identified, and the model was reconstructed only with the identified layer, and the performance indicators were compared and analyzed with the existing model. After learning the fire data using four transfer learning models: Xception, VGG19, ResNet, and EfficientNetB5, the Layer Importance Evaluation technique was applied to analyze the weight and activation value of each layer, and then a new model was constructed by selecting the top rank layers with the highest contribution. As a result of the study, it was confirmed that the implemented architecture maintains the same performance with parameters that are about 80% lighter than the existing model, and can contribute to increasing the efficiency of fire monitoring equipment by outputting the same performance in accuracy, loss, and confusion matrix indicators compared to conventional complex transfer learning models while having a learning speed of about 3 to 5 times faster.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.4
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• pp.325-332
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• 2001

The vestibular system located in the inner ear controls reflex body posture and movement, It has the semicircular canals sensing an angular acceleration and the otolith organs sensing a linear acceleration. With this organic signal, medical doctor decide if a person has disease or not. To obtain this data, a precision stimular system is considered. Robust control is needed to obtain eye signals induced by off-vertical axis rotation because of an unbalanced load produced by tilting the axis of the system upto 30 degrees. In this study, off-vertical axis rotatory system with visual stimulation system are developed. This system is consisted of head mounted display for generating horizontal, vertical, and three dimensional stimulus patterns. Furthermore wireless recording system using RF modem is considered for noiseless data transmission. Detailed data was described.

• Journal of Sensor Science and Technology
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• v.7 no.2
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• pp.83-89
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• 1998

$TiO_{2-x}$ thin film humidity sensors have been fabricated by sputtering method and their physical and hygroscopic characteristics have been investigated. The sputtering conditions and sintering conditions affect the sensor's sensitivity toward humidity. AES and SEM micrographs were taken for the analysis of crystal structures, surface morphology caused by adsorbed water vapour. $TiO_{2-x}$ humidity sensors showed negative impedance-humidity characteristics and the sensor which was fabricated by experimental condition 2(rf power of 200W) showed higher sensitivity and linearity than others. Then the slope of the sensor was about $0.794\;K{\Omega}/%RH$ and the response time of $TiO_{2-x}$ humidity sensors was about 2 min. for adsorption and about 3 min. for desorption at the operating temperature of $30^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.40 no.10
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• pp.973-980
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• 2003

The effects of additives in n-type semiconducting SnO$_2$-based gas sensors on oxidizing gases were investigated. The resistivity of SnO$_2$ sensors decreased when exposed to reducing gases, which act as electronic donors. However, the resistivities of the SnO$_2$ sensors increased when exposed to oxidizing gases, which act as electronic accepters. The products formed from the reaction of oxidizing gases ever SnO$_2$-based powders were analyzed by gas chromatography as compared with those formed from the reaction of reducing gases of alcohols. The SnO$_2$ sensors doped with PdCl$_2$ or A1$_2$O$_3$ showed unique dual response patterns toward oxidizing gases of $CH_3$CN and $CH_3$NO$_2$ depending on the operating temperature. The combination of these two sensors along with proper pattern recognition technique could enhance the selectivity for the gases with electron-accepting groups.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.11
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• pp.7-13
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• 2002

BSCT 320${\times}$240 IRFPA detector module is implemented, which is a key component in uncooled thermal imaging systems. The detector module consists of two parts, infrared sensitive pixel array and read-out integrated circuit(ROIC). The BSCT 320${\times}$240 pixels are made by laser scribe process and 10-${\mu}m$ micro-bump to satisfy 50-${\mu}m$ pitch and 95-% fill-factor. The ROIC has been designed to electrically address the pixels sequentailly and to improve signal-to-noise ratio with single transistor amplifier, HPF, tunable LPF and clamp circuit. The fabricated hybrid chip of detector and ROIC has been mounted on the TEC built-in ceramic package for more stable operation and tested for lots of electrical and optical properties. The IRFA sample has shown successful properties and met with good results of fill-factor, detectivity and responsivity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.1
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• pp.211-220
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• 2018

The standard data link layer encryption provided by CCSDS has a structure that encodes HDLC frame into it using an AES algorithm. However, CCSDS is standard method has a structure in which the receiving side cannot request a re-activation when noise interference occurs over an unstable channel. SES Alarmed has a structure that enables the receiving side to additionally detect errors and perform re-activation requests in an operational structure similar to that of link encryption in CCSDS. The SES Alarmed related paper was intended to identify the optimum range of thresholds and identify data corruption due to channel noise. In this paper, the focus was on reducing the re-activation process if the HDLC frame, excluding the password Sync code, consistently exceeds any threshold levels. The HDLC frame order was changed and the results of using SES Alarmed were proposed and compared.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.53-56
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• 2019

본 논문에서는 화력을 이용하는 대형 파워 플랜트 설비의 미세먼지 발생량을 저감시키고 능동적으로 제어 할 수 있는 효율적인 시스템을 제안한다. 이 시스템은 기존의 고정형으로 설계된 집진기 방식의 고정부하량 한계점과 극복하고 초미세먼지 PM2.5, 미세먼지 PM10의 발생량에 따라 IoT센서 감지에 의해 지능형 알고리즘으로 효율적으로 저감 제어 처리량을 극대화하고, 미세먼지 발생량을 최소화한다. 또한 이 시스템의 차별성은 기존의 집진기에서 잡혀지지 않는 초미세먼지를 새로운 형태의 물질인 FAA(Fine-dust Adsorption Agent)를 통해 연료 연소 시 발생되는 초미세먼지 미세입자 자체를 크게 만들어 기존 설비 집진기 필터에 포집되게 하는 혁신적인 방식이다. 이번 연구를 통해 350도~1000도 열원에서 작용할 수 있는 화학물질 FAA 용액(Agent)을 개발 하였으며 지능형 AI 분사장치를 통해 연료에 첨가되어 연소 시 미세먼지를 20배~50배까지 볼륨을 확대시켜 기존 집진필터에 포집될 수 있게 동작된다. 이때, 기존 설계된 집진기의 한계(부하)용량에 상관없이 미세먼지 발생량을 상황인식 반응형 알고리즘(AI제어) 통해 분사량을 능동적으로 조절하여 미세먼지 발생량을 저감하는 진보적 혁신성을 지닌다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.12
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• pp.1287-1295
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• 2015

Recently, fieldbus communication technologies have been widely deployed for industrial automation because they are profitable in providing easy system integration and management for multiple devices, as well as high-speed communication. It is essential for smart encoders to support fieldbus connectivity, where the device configuration and various types of information related to position are exchanged between an external controller and multiple encoders over the communication link. In this study, we implemented the CiA 406 device profile for smart encoders from the CANopen standards by extending an open-source CANopen standard-compliant framework, called CanFestival. The CiA 406 functionalities implemented in this study were validated on a test-bed consisting of a CANopen master and virtual CANopen encoders with our CiA 406 extension module.

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.103-111
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• 2011

The research has increased the role of physical activity in promoting health and preventing chronic disease. Estimating algorithm of physical activity energy expenditure was implemented by using a tri-axial accelerometer motion detector of the SVM(Signal Vector Magnitude) of 3-axis(x, y, z). COUNT method has been proven through experiments of validity Freedson, Hendelman, Leenders, Yngve was implemented by applying the SVM method. A total of 10 participants(5 males and 5 females aged between 20 and 30 years). The activity protocol consisted of three types on treadmill; participants performed three treadmill activity at three speeds(3, 5, 8 km/h). These activities were repeated four weeks. Customized estimating algorithm for energy expenditure of physical activities were implemented with COUNT and SVM correlation between the data.