• Title/Summary/Keyword: Sensor System

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A Study on the Use of Drones for Disaster Damage Investigation in Mountainous Terrain (산악지형에서의 재난피해조사를 위한 드론 맵핑 활용방안 연구)

  • Shin, Dongyoon;Kim, Dajinsol;Kim, Seongsam;Han, Youkyung;Nho, Hyunju
    • Korean Journal of Remote Sensing
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    • v.36 no.5_4
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    • pp.1209-1220
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    • 2020
  • In the case of forest areas, the installation of ground control points (GCPs) and the selection of terrain features, which are one of the unmanned aerial photogrammetry work process, are limited compared to urban areas, and safety problems arise due to non-visible flight due to high forest. To compensate for this problem, the drone equipped with a real time kinematic (RTK) sensor that corrects the position of the drone in real time, and a 3D flight method that fly based on terrain information are being developed. This study suggests to present a method for investigating damage using drones in forest areas. Position accuracy evaluation was performed for three methods: 1) drone mapping through GCP measurement (normal mapping), 2) drone mapping based on topographic data (3D flight mapping), 3) drone mapping using RTK drone (RTK mapping), and all showed an accuracy within 2 cm in the horizontal and within 13 cm in the vertical position. After evaluating the position accuracy, the volume of the landslide area was calculated and the volume values were compared, and all showed similar values. Through this study, the possibility of utilizing 3D flight mapping and RTK mapping in forest areas was confirmed. In the future, it is expected that more effective damage investigations can be conducted if the three methods are appropriately used according to the conditions of area of the disaster.

A Study on an Adaptive Guidance Plan by Quickest Path Algorithm for Building Evacuations due to Fire (건물 화재시 Quickest Path를 이용한 Adaptive 피난경로 유도방안)

  • Sin, Seong-Il;Seo, Yong-Hui;Lee, Chang-Ju
    • Journal of Korean Society of Transportation
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    • v.25 no.6
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    • pp.197-208
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    • 2007
  • Enormously sized buildings are appearing world-wide with the advancement of construction techniques. Large-scaled and complicated structures will have increased difficulties for dealing with safety, and will demand well-matched safety measures. This research introduced up-to-date techniques and systems which are applied in buildings in foreign nations. Furthermore, it proposed s direct guidance plan for buildings in case of fire. Since it is possible to install wireless sensor networks which detect fires or effects of fire, the plan makes use of this information. Accordingly, the authors completed a direct guidance plan that was based on omnidirectional guidance lights. It is possible to select a route with concern about both time and capacity with a concept of a non-dominated path. Finally, case studies showed that quickest path algorithms were effective for guiding efficient dispersion routes and in case of restriction of certain links in preferred paths due to temperature and smoke, it was possible to avoid relevant links and to restrict demand in the network application. Consequently, the algorithms were able to maximize safety and minimize evacuation time, which were the purposes of this study.

Development of Information Technology Infrastructures through Construction of Big Data Platform for Road Driving Environment Analysis (도로 주행환경 분석을 위한 빅데이터 플랫폼 구축 정보기술 인프라 개발)

  • Jung, In-taek;Chong, Kyu-soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.3
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    • pp.669-678
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    • 2018
  • This study developed information technology infrastructures for building a driving environment analysis platform using various big data, such as vehicle sensing data, public data, etc. First, a small platform server with a parallel structure for big data distribution processing was developed with H/W technology. Next, programs for big data collection/storage, processing/analysis, and information visualization were developed with S/W technology. The collection S/W was developed as a collection interface using Kafka, Flume, and Sqoop. The storage S/W was developed to be divided into a Hadoop distributed file system and Cassandra DB according to the utilization of data. Processing S/W was developed for spatial unit matching and time interval interpolation/aggregation of the collected data by applying the grid index method. An analysis S/W was developed as an analytical tool based on the Zeppelin notebook for the application and evaluation of a development algorithm. Finally, Information Visualization S/W was developed as a Web GIS engine program for providing various driving environment information and visualization. As a result of the performance evaluation, the number of executors, the optimal memory capacity, and number of cores for the development server were derived, and the computation performance was superior to that of the other cloud computing.

Evaluation of PPG signals regarding to video attributes of smart-phone camera (스마트폰 카메라의 영상 속성에 따른 맥파 신호 평가)

  • Lee, Haena;Kim, Minhee;Whang, MinCheol;Kim, Dong Keun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.4
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    • pp.917-924
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    • 2015
  • In this study, we study that the video attributes captured by built-in camera in smart-phone can effect on the quality of PPG signal. The conditions of video attributes were composed of the bitrate, the resolution, the flash. As each condition, we measured a change in the red value of the video image and calculated a PPI(Pulse to Pulse Interval) for extracting the pulse wave signal. 20 subjects participated in the experiment and this experiment was carried out 18 tasks. The PPG signal was measured simultaneously for two minutes with the PPG sensor in the middle finger and Smart-phone in the forefinger of the right hand. By proceeding the correlation analysis, we obtained the highest correlation condition(83%, p=0.01), which the resolution was $640{\times}480$, bitrate was 5000kbps, flash was on. As a result, this study will be a useful guide for quality of signals in the pulse signal measurement system using built-in camera in smart-phone.

Development of Device Measuring Real-time Air Flow in Greenhouse (온실 공기유동 계측 시스템 개발)

  • Noh, Jae Seung;Kwon, Jinkyoung;Kim, Yu Yong
    • Journal of Bio-Environment Control
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    • v.27 no.1
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    • pp.20-26
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    • 2018
  • This study was conducted to develop a device for measuring the air flow by space variation through monitoring program, which acquires data by each point from each environmental sensor located in the greenhouse. The distribution of environmental factors(air temperature, humidity, wind speed, etc.) in the greenhouse is arranged at 12 points according to the spatial variation and a large number of measurement points (36 points in total) on the X, Y and Z axes were selected. Considering data loss and various greenhouse conditions, a bit rate was at 125kbit/s at low speed, so that the number of sensors can be expanded to 90 within greenhouse with dimensions of 100m by 100m. Those system programmed using MATLAB and LabVIEW was conducted to measure distributions of the air flow along the greenhouse in real time. It was also visualized interpolated the spatial distribution in the greenhouse. In order to verify the accuracy of CFD modeling and to improve the accuracy, it will compare the environmental variation such as air temperature, humidity, wind speed and $CO_2$ concentration in the greenhouse.

PRELIMINARY FEASIBILITY STUDY OF THE SOLAR OBSERVATION PAYLOADS FOR STSAT-CLASS SATELLITES

  • Moon, Yong-Jae;Cho, Kyung-Seok;Jin, Ho;Chae, Jong-Chul;Lee, Sung-Ho;Seon, Kwang-Il;Kim, Yeon-Han;Park, Young-Deuk
    • Journal of Astronomy and Space Sciences
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    • v.21 no.4
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    • pp.329-342
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    • 2004
  • In this paper, we present preliminary feasibility studies on three types of solar observation payloads for future Korean Science and Technology Satellite (STSAT) programs. The three candidates are (1) an UV imaging telescope, (2) an UV spectrograph, and (3) an X-ray spectrometer. In the case of UV imaging telescope, the most important constraint seems to be the control stability of a satellite in order to obtain a reasonably good spatial resolution. Considering that the current pointing stability estimated from the data of the Far ultraviolet Imaging Spectrograph (FIMS) onboard the Korean STSAT-1, is around 1 arc minutes/sec, we think that it is hard to obtain a spatial resolution sufficient for scientific research by such an UV Imaging Telescope. For solar imaging missions, we realize that an image stabilization system, which is composed of a small guide telescope with limb sensor and a servo controller of secondary mirror, is quite essential for a very good pointing stability of about 0.1 arcsec. An UV spectrograph covering the solar full disk seems to be a good choice in that there is no risk due to poor pointing stability as well as that it can provide us with valuable UV spectral irradiance data valuable for studying their effects on the Earth's atmosphere and satellites. The heritage of the FIMS can be a great advantage of developing the UV spectrograph. Its main disadvantage is that two major missions are in operation or scheduled. Our preliminary investigations show that an X-ray spectrometer for the full disk Sun seems to be the best choice among the three candidates. The reasons are : (1) high temporal and spectral X-ray data are very essential for studying the acceleration process of energetic particles associated with solar flares, (2) we have a good heritage of X-ray detectors including a rocket-borne X-ray detector, (3) in the case of developing countries such as India and Czech, solar X-ray spectrometers were selected as their early stage satellite missions due to their poor pointing stabilities, and (4) there is no planned major mission after currently operating Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) mission. Finally, we present a preliminary design of a solar X-ray spectrometer covering soft X-ray (2 keV) to gamma ray (10 MeV).

Fundamental Research of Preservation & Utility Facilities in Wetland Protected Area - 5 Wetland Protected Areas were Used as Main Subjects - (습지보호지역의 습지보전·이용시설 현황에 관한 기초 연구 - 5개 습지보호지역을 대상으로 -)

  • Cho, Dong-Gil;Park, Yong-Su;Shim, Yun-Jin;Lee, Ji-Hyun;Lee, Dong-Jin;Kim, Sang-Hyuk;Cha, Jin-Yeol;Park, Mi-Young;Song, Yu-jin;Nam, Chun-hee;Kim, Jong-cheol;Moon, Sang-kyun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.19 no.1
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    • pp.25-43
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    • 2016
  • This research was completed to provide fundamental data regarding the guidelines to installing and managing utility facilities & structures in wetland protected area to advance the functions and sustainable use of ecology services by preserving the ecology within wetland protected area. There were 5 on-site researching areas that were used as the main subject with these areas chosen and considered from 21 inland wetlands that have been designated and are being managed from the Ministry of Environment and by their designated dates as a wetland protected area. The utility facilities in these wetland areas were categorized by their types and a detailed on-site investigation was proceeded with investigation items chosen whereas these facilities are working by their roles from their location, size, used materials, types, information contents and etc., The results showed that regarding informational structures, several locations of information boards were distanced from the main exploring routes which did not consider the visitor's eye level which had their readability dropped and by sunlight, time lapse and water penetration, many information boards were damaged or corrupted so that it was hard to confirm the information noticed or understanding an image. Insufficient observation and educational structures were installed that considered the ecological characteristics of wild animals and their living conditions. Regarding convenience facilities, there were parking lots that were installed on the fore-land and to decrease non-point solution sources, some parking lots needed to be located in protected lowlands while some facilities' shape and colors did not harmonize with their natural surroundings, creating a sense of awareness, which will need some more consideration. As for safety facilities, they were very insufficient compared to other facilities. This means that additional safety structures are needed so that related personnel can be aware of where a visitor is located when an accident occurs. Protectional facilities strongly needed new structures and a management system to cut off entrances and do surveillance so that visitors do not go into areas outside of the managed areas and bring damages to restricted locations. Research labs needed to expand the use of automatic weather systems and water gauge equipments to build fundamental data regarding floodgates that are intimated to the forming of wetlands. Sensor cameras and other types of monitoring systems are needed to monitor the majority types of animals living in the wetlands as well.

Adoption of the Use of Smart Technology by Health-care Workers in Nursing Homes: an Exploratory Study (노인요양시설의 스마트 기술 도입에 대한 탐색적 연구 -요양시설 종사자 답변을 중심으로-)

  • Lee, Sunhyung;Ahn, Joonhee
    • The Journal of the Korea Contents Association
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    • v.14 no.8
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    • pp.156-171
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    • 2014
  • The purpose of this exploratory study is to examine if the application of smart technology(ST) would assist adjustment to the nursing home facilities in the elderly. Since there is not much previous research on this subject, we generated survey questionnaires on our own. Data were collected from the survey of 127 employees at 6 nursing homes including geriatric care workers, social workers and nurses who provide direct as well as indirect care services. Results showed that the utilization of ST would benefit the areas of family relationship support, health support, leisure support, and physical environment adjustment. As for physical environment adjustment, study participants reported that ST would help elders familiarize employees and find directions for specific space the most. As for health support, ST would be best utilized as a security sensor and program alarm system. As for support for family relationship, ST was expected to be utilized as looking at family pictures and playing with self pictures/videos. As for leisure support, ST was expected to assist elders to listen to music and watch movies/TV. These results were different according to the characteristics of the participants and the smartifacts. These results of the study will show the direction for more in-depth studies on application of smart technology for the elderly in the future.

Body Temperature Monitoring Using Subcutaneously Implanted Thermo-loggers from Holstein Steers

  • Lee, Y.;Bok, J.D.;Lee, H.J.;Lee, H.G.;Kim, D.;Lee, I.;Kang, S.K.;Choi, Y.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.2
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    • pp.299-306
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    • 2016
  • Body temperature (BT) monitoring in cattle could be used to early detect fever from infectious disease or physiological events. Various ways to measure BT have been applied at different locations on cattle including rectum, reticulum, milk, subcutis and ear canal. In other to evaluate the temperature stability and reliability of subcutaneous temperature (ST) in highly fluctuating field conditions for continuous BT monitoring, long term ST profiles were collected and analyzed from cattle in autumn/winter and summer season by surgically implanted thermo-logger devices. Purposes of this study were to assess ST in the field condition as a reference BT and to determine any location effect of implantation on ST profile. In results, ST profile in cattle showed a clear circadian rhythm with daily lowest at 05:00 to 07:00 AM and highest around midnight and rather stable temperature readings (mean${\pm}$standard deviation [SD], $37.1^{\circ}C$ to $37.36^{\circ}C{\pm}0.91^{\circ}C$ to $1.02^{\circ}C$). STs are $1.39^{\circ}C$ to $1.65^{\circ}C$ lower than the rectal temperature and sometimes showed an irregular temperature drop below the normal physiologic one: 19.4% or 36.4% of 54,192 readings were below $36.5^{\circ}C$ or $37^{\circ}C$, respectively. Thus, for BT monitoring purposes in a fever-alarming-system, a correction algorithm is necessary to remove the influences of ambient temperature and animal resting behavior especially in winter time. One way to do this is simply discard outlier readings below $36.5^{\circ}C$ or $37^{\circ}C$ resulting in a much improved mean${\pm}$SD of $37.6^{\circ}C{\pm}0.64^{\circ}C$ or $37.8^{\circ}C{\pm}0.55^{\circ}C$, respectively. For location the upper scapula region seems the most reliable and convenient site for implantation of a thermo-sensor tag in terms of relatively low influence by ambient temperature and easy insertion compared to lower scapula or lateral neck.

Analysis on the Assist Characteristics for the Knee Extension Motion of Lower Limb Orthosis Using Muscular Stiffness Force Feedback (근육 강성도 힘 피드백을 이용한 하지 보조기의 무릎 신전 운동 보조 특성 분석)

  • Kim, K.;Kang, S.R.;Jeong, G.Y.;Joo, S.J.;Kim, N.G.;Kwon, T.K.
    • Journal of Biomedical Engineering Research
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    • v.31 no.3
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    • pp.217-226
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    • 2010
  • The lower limb orthosis with a pneumatic rubber actuator, which is intended for the assistance and the enhancement of muscular activities of lower limbs was developed in this study. Compared to other knee extension assistive devices being developed by other researchers, our device is designed especially for the elderly people and intended only for slight assistance so that the subjects can keep their muscular strength. For the effectiveness of system, muscular activities of major muscles in lower limbs during sit-to-stand (STS) and squat motion were measured and analyzed. Subjects were performed the STS and squat motion with and without lower limb orthosis. We made comparison muscular activities between with and without lower limb orthosis. Lower limb orthosis was controlled using muscular stiffness force feedback that is controlled by muscular activities of the measured muscle from force sensor. For analysis of muscular activities, electromyography of the subjects was measured during STS and squat motion, and these were measured using MP 150(BIOPAC Systems, Inc.). Muscles of interest were rectus femoris(RF), vastus lateralis(VL), vastus medialis(VM) and vastus intermedius(VI) muscles in lower limbs of the right side. A biodex dynamometer was used to measure the maximal concentric isokinetic strength of the knee extensors of wearing and not wearing orthosis on right side. The test were performed using the concentric isokinetic mode of test with the velocity set at 60°/s for muscles around the knee joints. The experimental result showed that muscular activities in lower limbs wearing orthosis using muscular stiffness force of a vastus medialis muscle was reduced and knee extension torque of an knee joint wearing lower limb orthosis was increased. With this, we confirmed the effectiveness of the developed lower limb orthosis.