• Title/Summary/Keyword: Sensor life time

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Optical Resonance-based Three Dimensional Sensing Device and its Signal Processing (광공진 현상을 이용한 입체 영상센서 및 신호처리 기법)

  • Park, Yong-Hwa;You, Jang-Woo;Park, Chang-Young;Yoon, Heesun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2013.10a
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    • pp.763-764
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    • 2013
  • A three-dimensional image capturing device and its signal processing algorithm and apparatus are presented. Three dimensional information is one of emerging differentiators that provides consumers with more realistic and immersive experiences in user interface, game, 3D-virtual reality, and 3D display. It has the depth information of a scene together with conventional color image so that full-information of real life that human eyes experience can be captured, recorded and reproduced. 20 Mega-Hertz-switching high speed image shutter device for 3D image capturing and its application to system prototype are presented[1,2]. For 3D image capturing, the system utilizes Time-of-Flight (TOF) principle by means of 20MHz high-speed micro-optical image modulator, so called 'optical resonator'. The high speed image modulation is obtained using the electro-optic operation of the multi-layer stacked structure having diffractive mirrors and optical resonance cavity which maximizes the magnitude of optical modulation[3,4]. The optical resonator is specially designed and fabricated realizing low resistance-capacitance cell structures having small RC-time constant. The optical shutter is positioned in front of a standard high resolution CMOS image sensor and modulates the IR image reflected from the object to capture a depth image (Figure 1). Suggested novel optical resonator enables capturing of a full HD depth image with depth accuracy of mm-scale, which is the largest depth image resolution among the-state-of-the-arts, which have been limited up to VGA. The 3D camera prototype realizes color/depth concurrent sensing optical architecture to capture 14Mp color and full HD depth images, simultaneously (Figure 2,3). The resulting high definition color/depth image and its capturing device have crucial impact on 3D business eco-system in IT industry especially as 3D image sensing means in the fields of 3D camera, gesture recognition, user interface, and 3D display. This paper presents MEMS-based optical resonator design, fabrication, 3D camera system prototype and signal processing algorithms.

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Implementation of CNN Model for Classification of Sitting Posture Based on Multiple Pressure Distribution (다중 압력분포 기반의 착석 자세 분류를 위한 CNN 모델 구현)

  • Seo, Ji-Yun;Noh, Yun-Hong;Jeong, Do-Un
    • Journal of the Institute of Convergence Signal Processing
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    • v.21 no.2
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    • pp.73-78
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    • 2020
  • Musculoskeletal disease is often caused by sitting down for long period's time or by bad posture habits. In order to prevent musculoskeletal disease in daily life, it is the most important to correct the bad sitting posture to the right one through real-time monitoring. In this study, to detect the sitting information of user's without any constraints, we propose posture measurement system based on multi-channel pressure sensor and CNN model for classifying sitting posture types. The proposed CNN model can analyze 5 types of sitting postures based on sitting posture information. For the performance assessment of posture classification CNN model through field test, the accuracy, recall, precision, and F1 of the classification results were checked with 10 subjects. As the experiment results, 99.84% of accuracy, 99.6% of recall, 99.6% of precision, and 99.6% of F1 were verified.

Design of Fire Evacuation Guidance System using USN Mesh Routing in High-Rise Buildings (초고층 건물 화재에서 USN 메쉬 라우팅을 이용한 피난유도 시스템 설계)

  • Choi, Yeon-Yi;Joe, In-Whee
    • Fire Science and Engineering
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    • v.22 no.3
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    • pp.278-286
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    • 2008
  • When big fire in high rise building and multiplex happens, the needs for high prevention system of disaster are being increased for getting the real-time scene state, quick lifesaver, and safe life security. In this paper the proposed evacuation guidance algorithm which analyzed the feature and danger of fire in high rise buildings, gave simplicity and scalability. Our research shows as fire and disaster occur in high rise buildings we construct sensor networks and sense realtime location information on fire alive people, and the situation information for fire instructed quick and safe escaping route by using mesh routing algorithm scheme relative to exit sign.

Study on DEVS Based Development that GPS Location Tracking System (DEVS 기반의 GPS 위치추적 시스템 개발에 관한 연구)

  • Seo, Hee Suk;Ju, Seung Hwan;Lee, Eun Jung;Lee, Seung Jae
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.6 no.3
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    • pp.1-8
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    • 2010
  • Recently, the missing due to the heinous crimes occurred in succession has been the focus of attention, so measures for these are urgently needed. So, it is necessary that we need to check and take care the weak like children, women, the elderly with dementia and insane person to prevent these social problems. This study is location-based service that suggests the tracking system and way to guard a family and property from the various risk factors which are possible in our life. To acquire the location of the user who is in motion, a communications network technologies were integrated and the system will be able to be monitoring in real time through the website. So, it is convenient and safe because it is possible to use anywhere. Concretely, it was described around location-based service, GPS system, tracking system, process of the service solution and composition for the system. Also, the way to activate the system will be suggested. The final suggested system was verified the possibility through the placement. With this, i will offer effective measures which is more convenient to use and reliable.

Wireless Buoy System with Remote Sensing and Access Capability (원격탐지기능을 갖는 무선부표시스템)

  • Kwon, Won-Hyun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.5B
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    • pp.549-556
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    • 2011
  • In this paper, high performance radio buoy system for inshore and deep sea fishery is proposed and implemented. Binary FSK modulation technique is used for real-time communication & control between buoys and buoy finder, and optimum access protocol is adopted for minimizing the power consumption of radio buoy system. Using the GPS and sensor techniques, location and environments of radio buoy can be accurately monitored and traced by the mother ship. Developed buoy system with 10 W transmitting power can cover over 120km coastal range and operate more than 73 days of battery life. Proposed digital coding methods can also assure high security from burglary and loss.

Development of Heat Shielding Part for RFID Tag using Porous Aluminum Alloy (알루미늄 다공성소재를 이용한 RFID Tag용 열차폐부품 개발)

  • Bang, Jae-Oh;Lee, Hyo-Soo;Jung, Taek-Kyun;Lee, Min-Ha;Kim, Bum-Sung;Jung, Seung-Boo
    • Journal of Powder Materials
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    • v.18 no.2
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    • pp.135-140
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    • 2011
  • The RFID (Radio-Frequency Identification) is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders. Some RFID tags have been used in severe environment of temperature ranged from $200^{\circ}C$ to $250^{\circ}C$ for a long time and may cause serious problems such as signal error, short life cycle and explosion. Conventionally, the RFID tags for high temperature applications consisted of Fe-alloy housing part, ceramic powder and RFID sensor. However, it has disadvantage of heavy weight, signal noise and heat shield capability. In this study, we newly applied the aluminum porous materials fabricated by polymer leaching process into RFID tags in order to improve heat shielding ability, and compared the properties of RFID tag inserted by aluminum porous with the conventional one.

Implementation of an Integrated Monitoring System for Constructional Structures Based on SaaS in Traditional Towns with Local Heritage (SaaS(Software as a Service) 기반 지방유적도시 구조물 유지관리계측 통합모니터링시스템 구현)

  • Min, Byung-Won;Oh, Yong-Sun
    • Proceedings of the Korea Contents Association Conference
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    • 2015.05a
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    • pp.15-16
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    • 2015
  • Measuring sensor, equipment, ICT facilities and their software have relatively short life time comparing to constructional structure so that we should exchange or fix them continuously in the process of maintenance and management. In this paper, we propose a novel design of integrated maintenance, management, and measuring monitoring system applying the concept of mobile cloud. For the sake of disaster prevention for constructional structures such as bridge, tunnel, and other traditional buildings in the village of local heritage, we analyze status of these structures in the long term or short term period as well as disaster situations. Collecting data based on mobile cloud and analyzing future expectations based on probabilistic and statistical techniques, we implement our integrated monitoring system for constructional structures to solve these existing problems. Final results of this design and implementation are basically applied to the monitoring system for more than 10,000 structures spread over national land in Korea. In addition, we can specifically apply the monitoring system presented here to a bridge of timber structure in Asan Oeam Village and a traditional house in Andong Hahoe Village to watch them from possible disasters. Total procedure of system design and implementation as well as development of the platform LinkSaaS and application services of monitoring functions implemented on the platform. We prove a good performance of our system by fulfilling TTA authentication test, web accommodation test, and operation test using real measuring data.

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A Generalized Calorie Estimation Algorithm Using 3-Axis Accelerometer

  • Choi, Jee-Hyun;Lee, Jeong-Whan;Shin, Kun-Soo
    • Journal of Biomedical Engineering Research
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    • v.27 no.6
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    • pp.301-309
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    • 2006
  • The main purpose of this study is to derive a regression equation that predicts the individual differences in activity energy expenditure (AEE) using accelerometer during different types of activity. Two subject groups were recruited separately in time: One is a homogeneous group of 94 healthy young adults with age ranged from $20\sim35$ yrs. The other subject group has a broad spectrum of physical characteristics in terms of age and fat ratio. 226 adolescents and adults of age ranged from $12\sim57$ yrs and fat ratio from $4.1\sim39.7%$ were in the second group. The wireless 3-axis accelerometers were developed and carefully fixed at the waist belt level. Simultaneously the total calorie expenditure was measured by gas analyzer. Each subject performed walking and running at speeds of 1.5, 3.0, 4.5, 6.0, 6.5, 7.5, and 8.5 km/hr. A generalized sensor-independent regression equation for AEE was derived. The regression equation was developed fur walking and running. The regression coefficients were predicted as functions of physical factors-age, gender, height, and weight with multivariable regression analysis. The generalized calorie estimation equation predicts AEE with correlation coefficient of 0.96 and the average accuracy of the accumulated calorie was $89.6{\pm}7.9%$.

Algorithm Improving Network Life-time Based on LEACH Protocol (LEACH 프로토콜 기반 망 수명 개선 알고리즘)

  • Choo, Young-Yeol;Choi, Han-Jo;Kwon, Jang-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.8A
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    • pp.810-819
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    • 2010
  • This paper proposes an algorithm to improve total network lifetime for Wireless Sensor Network (WSN) application such as environmental condition monitoring systems based on LEACH protocol. Firstly, the algorithm had equal number of nodes allocated to each cluster at cluster set-up phase where it abided by LEACH protocol. Secondly, at cluster set-up phase, each node was determined the order to be cluster header of the cluster which it had joined. After then, the role of a cluster head delivers to the next node according to determined order when the cluster head has received certain number of packets. With above method energy consumption of each node made equal and overall network lifetime was increased. Simulation results shows that overall network lifetime of proposed algorithm was increased two times than that of LEACH and total energy consumption was one forth of that of LEACH protocol.

Vibration Analysis of Bladed Disk using Non-contact Blade Vibration System (비접촉 진동측정 시스템을 이용한 블리스크의 진동분석)

  • Joung, Kyu-Kang;Kim, Myeong-Kuk;Park, Hee-Yong;Chen, Seung-Bae;Park, Noh-Gill
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.132-139
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    • 2008
  • The blade vibration problem of bladed disk is the most critical subject to consider since it directly affects the stable performance of the engine as well as life of the engine. Especially, due to complicated vibration pattern of the bladed disk, more effort was required for vibration analysis and test. The research of measuring the vibration of the bladed disk, using NSMS(Non-intrusive stress measurement) instead of Aeromechanics testing method requiring slip ring or telemetry system with strain gauge, was successful. These testing can report the actual stresses seen on the blades; detect synchronous resonances that are the source of high cycle fatigue (HCF) in blades; measure individual blade mis-tuning and coupled resonances in bladed disks. In order to minimize the error being created due to heat expansion, the tip timing sensor is installed parallel to the blade trailing edge, yielding optimal result. Also, when working on finite element analysis, the whole bladed disk has gone through three-dimensional analysis, evaluating the family mode. The result of the analysis matched well with the test result.

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