• Title/Summary/Keyword: 스마트미터

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Enhancement of Penetration by Using Mechenical Micro Needle in Textile Strain Sensor (텍스타일 스트레인 센서에 마이크로 니들을 이용한 전도성입자 침투력 향상)

  • Hayeong Yun;Wonjin Kim;Jooyong Kim
    • Science of Emotion and Sensibility
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    • v.25 no.4
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    • pp.45-52
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    • 2022
  • Recently, interest in and demand for sensors that recognize physical activity and their products are increasing. In particular, the development of wearable materials that are flexible, stretchable, and able to detect the user's biological signals is drawing attention. In this study, an experiment was conducted to improve the dip-coating efficiency of a single-walled carbon nanotube dispersion solution after fine holes were made in a hydrophobic material with a micro needle. In this study, dip-coating was performed with a material that was not penetrated, and comparative analysis was performed. The electrical conductivity of the sensor was measured when the sensor was stretched using a strain universal testing machine (Dacell Co. Ltd., Seoul, Korea) and a multimeter (Keysight Technologies, Santa Rosa, CA, USA) was used to measure resistance. It was found that the electrical conductivity of a sensor that was subjected to needling was at least 16 times better than that of a sensor that was not. In addition, the gauge factor was excellent, relative to the initial resistance of the sensor, so good performance as a sensor could be confirmed. Here, the dip-coating efficiency of hydrophobic materials, which have superior physical properties to hydrophilic materials but are not suitable due to their high surface tension, can be adopted to more effectively detect body movements and manufacture sensors with excellent durability and usability.

A Study about Learning Graph Representation on Farmhouse Apple Quality Images with Graph Transformer (그래프 트랜스포머 기반 농가 사과 품질 이미지의 그래프 표현 학습 연구)

  • Ji Hun Bae;Ju Hwan Lee;Gwang Hyun Yu;Gyeong Ju Kwon;Jin Young Kim
    • Smart Media Journal
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    • v.12 no.1
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    • pp.9-16
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    • 2023
  • Recently, a convolutional neural network (CNN) based system is being developed to overcome the limitations of human resources in the apple quality classification of farmhouse. However, since convolutional neural networks receive only images of the same size, preprocessing such as sampling may be required, and in the case of oversampling, information loss of the original image such as image quality degradation and blurring occurs. In this paper, in order to minimize the above problem, to generate a image patch based graph of an original image and propose a random walk-based positional encoding method to apply the graph transformer model. The above method continuously learns the position embedding information of patches which don't have a positional information based on the random walk algorithm, and finds the optimal graph structure by aggregating useful node information through the self-attention technique of graph transformer model. Therefore, it is robust and shows good performance even in a new graph structure of random node order and an arbitrary graph structure according to the location of an object in an image. As a result, when experimented with 5 apple quality datasets, the learning accuracy was higher than other GNN models by a minimum of 1.3% to a maximum of 4.7%, and the number of parameters was 3.59M, which was about 15% less than the 23.52M of the ResNet18 model. Therefore, it shows fast reasoning speed according to the reduction of the amount of computation and proves the effect.

Distributed evacuation guide system based on positioning information of passengers in the subway station (승객 위치정보 기반 지하철 분산대피 안내 시스템)

  • Kim, Nammoon;Kim, Youngok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.7
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    • pp.4528-4535
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    • 2014
  • In this paper, a distributed evacuation system based on the positioning information of subway passengers is proposed. Recently, the subway station is becoming complicated by combining with shopping malls, and movie theaters. Compared to the increasing complexity of subway stations, evacuation systems are less complex. Subway passengers in each cell were estimated to use the access point in the subway cells and statistics information. The evacuation route is provided through a direction indicator and push alarm of a smart phone based on estimated the number of passengers and exit information of the subway station. Based on this schemes, a quick and safe evacuation system of subway passengers was proposed. The number of connection passengers was estimated using AP with OpenWrt embedded OS installed. The average error rate of the number of passenger was confirmed to be 15%, 17% and 23% at the confidence parameter of $1{\sigma}$, $2{\sigma}$, and $3{\sigma}$, respectively, through a simulation. The possibility of the system through a simple experiment was examined.

Implementation and Performance Analysis of PLC Scheme based on SISO/MIMO-OFDM using MRC (최대비 합성법을 이용한 SISO/MIMO-OFDM 기반 전력선 통신 방식 구현 및 성능분석)

  • Yoo, Jeong-Hwa;Choe, Sang-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.2B
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    • pp.176-183
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    • 2011
  • In this paper, we propose the implementation and performance analysis of power line communication based on SISO/MIMO-OFDM which focuses on high speed data transmission in smart grid and future power line grid. We employ Zimmermann frequency model and Middleton Class A model as the multipath power line fading channel and impulse noise channel, respectively. In this paper, in order to improve the three-phase or single-phase PLC performance, we introduce a new MRC (called a&f-MRC) which effectively sums up multiple antenna diversity gain and multipath fading diversity gain. Via simulation, we prove the performance advantage over existing SISO/MIMO systems. In addition, we offer the tradeoff on system design through comparing with MRC, EGC and SC.

Positioning Method Using a Vehicular Black-Box Camera and a 2D Barcode in an Indoor Parking Lot (스마트폰 카메라와 2차원 바코드를 이용한 실내 주차장 내 측위 방법)

  • Song, Jihyun;Lee, Jae-sung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.1
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    • pp.142-152
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    • 2016
  • GPS is not able to be used for indoor positioning and currently most of techniques emerging to overcome the limit of GPS utilize private wireless networks. However, these methods require high costs for installation and maintenance, and they are inappropriate to be used in the place where precise positioning is needed as in indoor parking lots. This paper proposes a vehicular indoor positioning method based on QR-code recognition. The method gets an absolute coordinate through QR-code scanning, and obtain the location (an relative coordinate) of a black-box camera using the tilt and roll angle correction through affine transformation, scale transformation, and trigonometric function. Using these information of an absolute coordinate and an relative one, the precise position of a car is estimated. As a result, average error of 13.79cm is achieved and it corresponds to just 27.6% error rate in contrast to 50cm error of the recent technique based on wireless networks.

Development of Wireless Data Acquisition Device for Individual Load to Improve Function of Smart Meter Applied to AMI (AMI 적용 스마트 미터 기능향상을 위한 개별부하 상세 데이터 무선 취득장치 개발)

  • Sung, Byung-Chul;Bae, Sun-Ho;Park, Woo-Jae;Jeon, Seung-Wook;Park, Jung-Wook
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.10
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    • pp.1795-1803
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    • 2011
  • Advanced Metering Infrastructure (AMI) is one of the important components to form a smart-gird, which is an advanced power system by combining the power system with the communication systems. This AMI makes it possible to exchange information between operators and consumers for the efficient and reliable operation of the power system through a smart meter or a In-Home Display. However, according to the increase of the demanded information such as the power quality, the accurate load-profile, and the billing data to help customers manage their power consumption, it is necessary to gather more accurate analytical data from each house appliances and transfer it to the smart meter for synthesizing the information and controlling each loads. In this paper, the development of the wireless data acquisition device for the individual load data metering, which is connected with the smart meter for advanced functions, is proposed. AVR, a kind of microcontroller, and Bluetooth are used and integrated into the proposed the wireless data acquisition device to transmit the detailed power data (voltage and current) to the smart meter. To verify the effectiveness of the proposed system, a hardware experiment is carried out including the confirmation of the possibility for providing the more various information by applying analysis algorithms to the obtained data. Also, the application structure of the wireless data acquisition device to gather the data from the various house appliances is presented.

WAVE System Performance for Platooning Vehicle Service Requirements Under Highway Environments (고속도로 환경에서 군집주행 서비스 요구사항에 대한 WAVE 통신시스템 성능 분석)

  • Song, Yoo-seung;Choi, Hyun Kyun
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.16 no.1
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    • pp.147-156
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    • 2017
  • This paper analyzes the performance limit of WAVE system for the platooning service requirements which is referred from the de facto standards. The performance of the packet error rate and mean delay as key parameters in the wireless communication systems should be satisfied to provide safety to the platooning vehicles. The test scenarios are conducted by considering the following vehicle groups: platooning vehicles, vehicles within a hop distance and vehicles within two hop distance( called hidden node vehicles). The models of packet error rate and delay deals with the topology of aforementioned vehicle groups, vehicle speed and communication range. The numerical results are obtained in terms of packet size, packet arrival rate and data transmission rate. Finally, this paper suggests the robust range of packet error rate and delay for the WAVE system to provide the platooning vehicle service.

A Novel LTE Downlink Codebook for Rician Fading Channels (Rician 페이딩 채널에 적합한 새로운 LTE 하향링크 코드북)

  • Yan, Zhi Fei;Kim, Young-Ju
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.48 no.1
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    • pp.70-76
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    • 2011
  • LTE Re1-10 aims at peak. data rates of 1Gbits/s for the downlink and 500 Mbits/s for the uplink, which can be accomplished by not only wide spectrum but also advanced MIMO techniques such as precoded MIMO and cooperative relays. Considering some relays can have more direct signal paths than mobile stations do, LoS components are examined to build more efficient codebooks for Rician channels. The proposed codebooks perform better than the existing LTE codebooks as the criterium of LoS, K-factor increases. Conserving the advantages and max-min chordal distance of the existing LTE codebooks, the proposed ones also maximize the minimum chordal distances between codewords over Rician fading channels. Link-level simulation with LTE system parameters confirm the performance improvements as the value of K increases.

he deposition and analysis of ITO thin film by DC magnetron sputter at room temperature (DC 마그네트론 스펏터를 이용한 ITO 박막의 실온 증착 및 특성 분석)

  • Kim, Howoon;Yun, Jung-Oh
    • Journal of IKEEE
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    • v.24 no.1
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    • pp.59-66
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    • 2020
  • In this study, the characteristics of ITO thin film was investigated to finding a low cost and highly transparent electrodes for display of mobile communication devices. The ITO film was deposited by DC magnetron sputter. The experimental conditions were changed as follows: 1. ambient pressure changed 1 to 3 mTorr with 1mTorr step, 2. bias electric voltage changed with 10V step. The chamber was pumped out by rotary pump until 10-3Torr then the diffusion pump was used to lower the pressure of 10-6Torr. The results shows us the film growth was obvious when the bias voltage was larger than 300V, but the overall thickness tendency was existed: the more voltage is the thicker thickness. At 330V bias voltage condition, the deposition rate was the largest and apparent grain was showed.

Development and Performance Test of DC Smart Metering System for the DC Power Measurement of Urban Railway (도시철도 직류 전력량 계측을 위한 직류용 스마트미터링 시스템 개발 및 성능시험)

  • Jung, Hosung;Shin, Seongkuen;Kim, Hyungchul;Park, Jongyoung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.5
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    • pp.713-718
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    • 2014
  • DC urban railway power system consists of DC power network and AC power network. The DC power network supplies electric power to railway vehicles and the AC power network supplies electric power to station electric equipment. Recently, because of power consumption reduction and peak load shaving, intelligent measurement of regenerative energy and renewable energy adapted on DC urban railway is required. For this reason, DC smart metering system for DC power network shall be developed. Therefore, in this paper, DC voltage sensor, current sensor, and DC smart meter were developed and evaluated by performance test. DC voltage sensor was developed for measuring standard voltage range of DC urban railway, and DC current sensor was developed as hall effect split core type in order to install in existing system. DC smart meter possesses function of general intelligent electric power meter, such as measuring electricity and wireless communication etc. And, DC voltage sensor showed average 0.17% of measuring error for 2,000V/50mA, and current sensor showed average 0.21% of measuring error for ${\pm}2,000V/{\pm}4V$ in performance test. Also DC smart meter showed maximum 0.92% of measuring error for output of voltage sensor and current sensor. In similar environment for real DC power network, measuring error rate was under 0.5%. In conclusion, accuracy of DC smart metering system was confirmed by performance test, and more detailed performance will be verified by further real operation DC urban railway line test.