• Title/Summary/Keyword: Sensor Control

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The Scientific Analysis of Aged' Shoe for Health Promotion (노인 건강증진용 신발의 운동과학적 효과분석)

  • Jin, Young-Wan;Kwak, Yi-Sub
    • Journal of Life Science
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    • v.21 no.9
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    • pp.1336-1345
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    • 2011
  • The purpose of this study was to analyze and compare the effects of exercise science of shoes for Aged' health promotion. Kinematic and kinetic data were collected using cinematography and the Zebris system (Zebris Emed Sensor Platform, GR-DVL9800) to analyze pressure of foot and ground reaction force. Subjects recruited were 20 healthy elderly men. They walked at 1.36m/sec velocity wearing type A (domestic), type B (foreign) and walking shoes (A company). One-way ANOVA was used to analyze statistics. The results were as following: no significant differences were observed in gait variables among the three groups (p<0.05). There was a significant difference in max pronation angle of heels examined among the three groups (p<0.05). There were no significant differences in kinetic variables (ground reaction force and max pressure) among the three groups (p<0.05). A physiology study was performed to analyze the effects of walking with shoes with silver added to them on percent body fat, resting metabolic rate and energy expenditure. Sixty adults males were recruited from the public health center. They were divided into four groups. C: control group (n=20), EY: elderly Y group (n=20), and EO: elderly O group (n=20). The results of this study were as follows: percent body fat was decreased following each exercise period, however, not all the groups showed a significant difference. The change of resting metabolic rate was significantly increased in HI (high intensity) and LI (low intensity) periods in the C and EY groups. However, there was no significant difference in the EO group. The mean energy expenditure during and after exercise were significantly lowered in all periods compared to the control group.

USN's Efforts to Rebuild its Combat Power in an Era of Great Power Competition (강대국 간의 경쟁시대와 미 해군의 증강 노력)

  • Jung, Ho-Sub
    • Strategy21
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    • s.44
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    • pp.5-27
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    • 2018
  • The purpose of this paper is to look at USN's efforts to rebuild its combat power in the face of a reemergence of great powers competition, and to propose some recommendations for the ROKN. In addition to the plan to augment its fleet towards a 355-ships capacity, the USN is pursuing to improve exponentially combat lethality(quality) of its existing fleet by means of innovative science and technology. In other words, the USN is putting its utmost efforts to improve readiness of current forces, to modernize maintenance facilities such as naval shipyards, and simultaneously to invest in innovative weapons system R&D for the future. After all, the USN seems to pursue innovations in advanced military Science & Technology as the best way to ensure continued supremacy in the coming strategic competition between great powers. However, it is to be seen whether the USN can smoothly continue these efforts to rebuild combat strength vis-a-vis its new competition peers, namely China and Russian navy, due to the stringent fiscal constraints, originating, among others, from the 2011 Budget Control Act effective yet. Then, it seems to be China's unilateral and assertive behaviors to expand its maritime jurisdiction in the South China Sea that drives the USN's rebuild-up efforts of the future. Now, some changes began to be perceived in the basic framework of the hitherto regional maritime security, in the name of declining sea control of the USN as well as withering maritime order based on international law and norms. However, the ROK-US alliance system is the most excellent security mechanism upon which the ROK, as a trading power, depends for its survival and prosperity. In addition, as denuclearization of North Korea seems to take significant time and efforts to accomplish in the years to come, nuclear umbrella and extended deterrence by the US is still noting but indispensible for the security of the ROK. In this connection, the naval cooperation between ROKN and USN should be seen and strengthened as the most important deterrents to North Korean nuclear and missile threats, as well as to potential maritime provocation by neighboring countries. Based on these observations, this paper argues that the ROK Navy should try to expand its own deterrent capability by pursuing selective technological innovation in order to prevent this country's destiny from being dictated by other powers. In doing so, however, it may be too risky for the ROK to pursue the emerging, disruptive innovative technologies such as rail gun, hypersonic weapon... etc., due to enormous budget, time, and very thin chance of success. This paper recommends, therefore, to carefully select and extensively invest on the most cost-effective technological innovations, suitable in the operational environments of the ROK. In particular, this paper stresses the following six areas as most potential naval innovations for the ROK Navy: long range precision strike; air and missile defense at sea; ASW with various unmanned maritime system (UMS) such as USV, UUV based on advanced hydraulic acoustic sensor (Sonar) technology; network; digitalization for the use of AI and big data; and nuclear-powered attack submarines as a strategic deterrent.

A Basic Study on Miniature Size Electrostatic Induction Meter (소형(小型) 정전(靜電) 유도형(誘導型) 모터의 기초(基礎) 연구(硏究))

  • Moon, Jae-Duk;Lee, Dong-Hoon
    • Journal of Sensor Science and Technology
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    • v.2 no.1
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    • pp.65-74
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    • 1993
  • A miniature size electrostatic induction motor has been fabricated and studied with emphasis on the role of the surface resistivity, the relative dielectric constant and the charge relaxation time constant of the rotor surface materials and the rotor liner materials, which, however, control the surface charge induction and relaxation on the rotor material surface and the field intensity between the rotor and the stator of the motor. It is found that the surface resistivity and/or the relative dielectric constant, and the charge relaxation time constant of the rotor surface material enfluenced significantly to motor speed controlled by the surface charge induction and relaxation on the rotor surface depending on the applied voltage and/or frequency changing. The resistivity of the rotor liner material is also found to be effected to the motor speed greatly by control of the field intensity between the rotor and the stator and of the surface charge distribution of the induced charge on the rotor. As a result, a maximum no load rotor speed of the motor tested was about 5500 rpm at the applied voltage of 4.5 kV and the frequency of 220 Hz for the case of the rotor surface material of $BaTiO_{3}$ 80% in the resin binder layered on the copper-foil rotor liner material.

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Design and Implementation of the Management System of Cultivation and Tracking for Agricultural Products using USN (유비쿼터스 센서 네트워크를 이용한 농산물 재배관리 및 이력추적 시스템의 설계 및 구현)

  • Yoo, Nam-Hyun;Song, Gil-Jong;Yoo, Ju-Hyun;Yang, Su-Yeong;Son, Cheol-Su;Koh, Jing-Wang;Kim, Won-Jung
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.9
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    • pp.661-674
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    • 2009
  • Recently, there has been much research and many attempts to enhance converged information technology services using new technology such as ubiquitous sensor networks (USN) in medical, environmental, industrial, and logistic areas. There has also been much research and various attempts to apply this new technology to agricultural areas. However, applications to the agricultural areas should be considered differently against the same areas such as medical, environmental, industrial, and logistics. Therefore, this paper suggests that an agricultural cultivating management and traceability system. This system is a unified system that supports the processes sowing seeds through selling agricultural products to consumers. Farmers can be provided with an effective calendar for cultivation and weather information in real time as well as the monitoring of the growth of farm products on the farm in real time using this system. Farmers can also control all equipment installed on the farm directly or remotely and the equipment can be controlled automatically when the measured values such as temperature and humidity deviate from the decent criteria which are set by farmers or this system. Additionally, the reliability for and the better quality of the agricultural products can be improved because farmers can use this unified system to cover all processes from sowing seeds to selling to consumers.

Performance Analysis of Sensor Network Real-Time Traffic for Factory Automation in Intranet Environment (인트라넷 환경에서의 공장자동화를 위한 센서 망 실시간 트래픽 성능 평가)

  • Song, Myoung-Gyu;Choo, Young-Yeol
    • Journal of Korea Multimedia Society
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    • v.11 no.7
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    • pp.1007-1015
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    • 2008
  • In order to provide real-time data from sensors and instruments at manufacturing processes on web, we proposed a communication service model based on XML(eXtensible Markup Language). HTML(Hyper Text Markup Language) is inadequate for describing real-time data from manufacturing plants while it is suitable for display of non-real-time multimedia data on web. For applying XML-based web service of process data in Intranet environment, real-time performance of communication services was evaluated to provide the system design criteria. XML schema for the data presentation was proposed and its communication performance was evaluated by simulation in terms of transmission delay due to increased message length and processing delay for transformation of raw data into defined format. For transformation of raw data into XML format, we proposed two structures: one is the scheme where transformation is done at an SCC(Supervisory Control Computer) after receiving real-time data from instruments. the other is the scheme where transformation is carried out at instruments before the data are transmitted to the SCC. Performances of two structures were evaluated on a testbed under various conditions such as six packet sizes and offered loads of 20%, 50% and 80%, respectively. Test results show that proposed schemes are applicable to the systems in Ethernet 100BaseT network if total message traffic is less than 7 Mbps.

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Development of a Trial Product for Irrigation Management in Substrate Culture (고형배지경 급액관리 시작기 개발)

  • Kim, Sung-Eun;Sim, Sang-Youn;Lee, Sang-Don;Kim, Young-Shik
    • Journal of agriculture & life science
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    • v.44 no.5
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    • pp.129-135
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    • 2010
  • This experiment was carried out to commercialize an irrigation control system by finding out problems and solving them in application of a nutrient supply system through this experiment. Its efficiency had been tested through hydroponic cultivation of tomato and cucumber using this system in the farmer's plastic house (1-2W, 20a : Yanggyo-ri, Oseong-myeon Gyeonggi-do) from November. 2006, too. In the first cultivation, tomato seeds (cultivar Coco, Takii Seed Co. Japan) were sowed on November 8, 2006, and transplanted on January 8, 2007. and then, in the second, cucumber (Chuichong, Nongwoo Seed Co.) were cultivated in the same plastic house (sowing date : June 27, transplanting date : July 13). In the third, another cucumber cultivar (Jo-woon, Dongbu-hannong Seed Co.) were cultivated (sowing date : September 5, transplanting date : September 23). All of seedlings were transplanted on perlite bag ($W340{\times}L1,200{\times}H150mm$, 40L). By using this system, 971 boxes (5 kg/box) of tomato were produced and sold, and then total income was 5,466 thousand won per 10a. On the second cultivation, total amount of cucumber production was 489 boxes (50 ea/box), and total income was 7,380 thousand won. On the third cultivation, total amount of production was 67 boxes (100 ea/box), and total income was 1,854 thousand won. On the other hand, this system saved irrigated water by 50% ($4,000{\rightarrow}2,000L/10a/day$) in tomato cultivation, and by 44%($4,500{\rightarrow}2,500L/10a/day$) in cucumber cultivation. It also saved cost of nutrients by 50% in tomato ($1,648{\rightarrow}824thousand\;won/10a$), and 44% in cucumber ($1,648{\rightarrow}725thousand\;won/10a$). Furthermore this irrigation system maintained moisture content in perlite bag stable during cultivation period. Therefore, this system was successfully applied on farmer's greenhouse without a problem and can be commercialized for farmers.

Evaluation of International Quality Control Procedures for Detecting Outliers in Water Temperature Time-series at Ieodo Ocean Research Station (이어도 해양과학기지 수온 시계열 자료의 이상값 검출을 위한 국제 품질검사의 성능 평가)

  • Min, Yongchim;Jun, Hyunjung;Jeong, Jin-Yong;Park, Sung-Hwan;Lee, Jaeik;Jeong, Jeongmin;Min, Inki;Kim, Yong Sun
    • Ocean and Polar Research
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    • v.43 no.4
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    • pp.229-243
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    • 2021
  • Quality control (QC) to process observed time series has become more critical as the types and amount of observed data have increased along with the development of ocean observing sensors and communication technology. International ocean observing institutions have developed and operated automatic QC procedures for these observed time series. In this study, the performance of automated QC procedures proposed by U.S. IOOS (Integrated Ocean Observing System), NDBC (National Data Buy Center), and OOI (Ocean Observatory Initiative) were evaluated for observed time-series particularly from the Yellow and East China Seas by taking advantage of a confusion matrix. We focused on detecting additive outliers (AO) and temporary change outliers (TCO) based on ocean temperature observation from the Ieodo Ocean Research Station (I-ORS) in 2013. Our results present that the IOOS variability check procedure tends to classify normal data as AO or TCO. The NDBC variability check tracks outliers well but also tends to classify a lot of normal data as abnormal, particularly in the case of rapidly fluctuating time-series. The OOI procedure seems to detect the AO and TCO most effectively and the rate of classifying normal data as abnormal is also the lowest among the international checks. However, all three checks need additional scrutiny because they often fail to classify outliers when intermittent observations are performed or as a result of systematic errors, as well as tending to classify normal data as outliers in the case where there is abrupt change in the observed data due to a sensor being located within a sharp boundary between two water masses, which is a common feature in shallow water observations. Therefore, this study underlines the necessity of developing a new QC algorithm for time-series occurring in a shallow sea.

Estimation of the Dimensions of Horticultural Products and the Mean Plant Height of Plug Seedlings Using Three-Dimensional Images (3차원 영상을 이용한 원예산물의 크기와 플러그묘의 평균초장 추정)

  • Jang, Dong Hwa;Kim, Hyeon Tae;Kim, Yong Hyeon
    • Journal of Bio-Environment Control
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    • v.28 no.4
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    • pp.358-365
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    • 2019
  • This study was conducted to estimate the dimensions of horticultural products and the mean plant height of plug seedlings using three-dimensional (3D) images. Two types of camera, a ToF camera and a stereo-vision camera, were used to acquire 3D images for horticultural products and plug seedlings. The errors calculated from the ToF images for dimensions of horticultural products and mean height of plug seedlings were lower than those predicted from stereo-vision images. A new indicator was defined for determining the mean plant height of plug seedlings. Except for watermelon with tap, the errors of circumference and height of horticultural products were 0.0-3.0% and 0.0-4.7%, respectively. Also, the error of mean plant height for plug seedlings was 0.0-5.5%. The results revealed that 3D images can be utilized to estimate accurately the dimensions of horticultural products and the plant height of plug seedlings. Moreover, our method is potentially applicable for segmenting objects and for removing outliers from the point cloud data based on the 3D images of horticultural crops.

A Study on the Power Converter Control of Utility Interactive Photovoltaic Generation System (계통 연계형 태양광 발전시스템의 전력변환기 제어에 관한 연구)

  • Na, Seung-Kwon;Ku, Gi-Jun;Kim, Gye-Kuk
    • Journal of the Korea Society of Computer and Information
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    • v.14 no.2
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    • pp.157-168
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    • 2009
  • In this paper, a photovoltaic system is designed with a step up chopper and single phase PWM(Pulse Width Modulation) voltage source inverter. Where proposed Synchronous signal and control signal was processed by one-chip microprocessor for stable modulation. The step up chopper operates in continuous mode by adjusting the duty ratio so that the photovoltaic system tracks the maximum power point of solar cell without any influence on the variation of insolation and temperature because solar cell has typical voltage and current dropping character. The single phase PWM voltage source the inverter using inverter consists of complex type of electric power converter to compensate for the defect, that is, solar cell cannot be developed continuously by connecting with the source of electric power for ordinary use. It can cause the effect of saving electric power. from 10 to 20[%]. The single phase PWM voltage source inverter operates in situation that its output voltage is in same phase with the utility voltage. In order to enhance the efficiency of photovoltaic cells, photovoltaic positioning system using sensor and microprocessor was design so that the fixed type of photovoltaic cells and photovoltaic positioning system were compared. In result, photovoltaic positioning system can improved 5% than fixed type of photovoltaic cells. In addition, I connected extra power to the system through operating the system voltage and inverter power in a synchronized way by extracting the system voltage so that the phase of the system and the phase of single-phase inverter of PWM voltage type can be synchronized. And, It controlled in order to provide stable pier to the load and the system through maintaining high lurer factor and low output power of harmonics.

Comparison of Feature Point Extraction Algorithms Using Unmanned Aerial Vehicle RGB Reference Orthophoto (무인항공기 RGB 기준 정사영상을 이용한 특징점 추출 알고리즘 비교)

  • Lee, Kirim;Seong, Jihoon;Jung, Sejung;Shin, Hyeongil;Kim, Dohoon;Lee, Wonhee
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.44 no.2
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    • pp.263-270
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    • 2024
  • As unmanned aerial vehicles(UAVs) and sensors have been developed in a variety of ways, it has become possible to update information on the ground faster than existing aerial photography or remote sensing. However, acquisition and input of ground control points(GCPs) UAV photogrammetry takes a lot of time, and geometric distortion occurs if measurement and input of GCPs are incorrect. In this study, RGB-based orthophotos were generated to reduce GCPs measurment and input time, and comparison and evaluation were performed by applying feature point algorithms to target orthophotos from various sensors. Four feature point extraction algorithms were applied to the two study sites, and as a result, speeded up robust features(SURF) was the best in terms of the ratio of matching pairs to feature points. When compared overall, the accelerated-KAZE(AKAZE) method extracted the most feature points and matching pairs, and the binary robust invariant scalable keypoints(BRISK) method extracted the fewest feature points and matching pairs. Through these results, it was confirmed that the AKAZE method is superior when performing geometric correction of the objective orthophoto for each sensor.