• Title/Summary/Keyword: SG Measurement

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Detecting Anomalies in Time-Series Data using Unsupervised Learning and Analysis on Infrequent Signatures

  • Bian, Xingchao
    • Journal of IKEEE
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    • v.24 no.4
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    • pp.1011-1016
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    • 2020
  • We propose a framework called Stacked Gated Recurrent Unit - Infrequent Residual Analysis (SG-IRA) that detects anomalies in time-series data that can be trained on streams of raw sensor data without any pre-labeled dataset. To enable such unsupervised learning, SG-IRA includes an estimation model that uses a stacked Gated Recurrent Unit (GRU) structure and an analysis method that detects anomalies based on the difference between the estimated value and the actual measurement (residual). SG-IRA's residual analysis method dynamically adapts the detection threshold from the population using frequency analysis, unlike the baseline model that relies on a constant threshold. In this paper, SG-IRA is evaluated using the industrial control systems (ICS) datasets. SG-IRA improves the detection performance (F1 score) by 5.9% compared to the baseline model.

Effect of Weak-part Strengthening Training and Strong-part Relaxation Therapy on Static Balance, Muscle Strength Asymmetry, and Proprioception in the Gluteus Medius: Immediate Effect Analysis

  • Choi, Eun-Bi;Jung, Yu-Jin;Lee, Dongyeop;Hong, Ji-Heon;Yu, Jae-Ho;Kim, Jin-Seop;Kim, Seong-Gil
    • Journal of the Korean Society of Physical Medicine
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    • v.17 no.2
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    • pp.11-20
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    • 2022
  • PURPOSE: This study investigated the immediate effects of gluteus medius strengthening training and relaxation therapy on the static balance, muscle strength asymmetry, and proprioception. METHODS: In this research, 38 healthy adults were assigned randomly to strengthening groups (SG) and relaxation groups (RG). The static balance, muscle strength asymmetry, and proprioception were measured as a pre-measurement. The same measurements were performed after the intervention and follow-up. An independent sample t-test was used to compare each group, and one-way repeated ANOVA was used to compare the changes within the group. RESULTS: In the static balance, the comparison between groups SG was more significant than RG, and only SG showed significant differences in the intra-group comparisons. There was no significant difference in muscle strength asymmetry between SG and RG. On the other hand, the comparison within the group revealed only SG to be significant. In proprioception, SG produced more significant results than RG, and only SG had significant values in the within-group comparison. CONCLUSION: Strengthening training affects the changes in static balance, muscle strength asymmetry, and proprioception.

An investigation on the in si.tu measurement of the oil-concentration

  • Kim, Chang-Nyeun;Park, Young-Moo
    • International Journal of Air-Conditioning and Refrigeration
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    • v.9 no.1
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    • pp.20-28
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    • 2001
  • In order to predict thermodynamic performance of refrigeration system, it is required to know the oil concentration of the refrigerant/oil mixture. The current method is to extract the working mixture and then to measure the oil weight. In this study, oil concentration is measured in si.tu way without any extraction of the working fluid. Based on the measurement, a working equation is presented as follows, C=a +b x t +c x $t^2$ +(d + e x t +f x $t^2$) x SG. C is oil concentration, t is temperature($^{\circ}C). SG Is specific gravity of mixture and a~f is coefficients The oil concentration ranges over 0~l2 wt% and the temperature ranges over 20~50$^{\circ}C. The specific gravity and temperature are measured using the on-line densimeter and thermometer. This working equation enables to predict the oil concentration without any extraction of the mixture. This equation can be applied for R-12/Naphthenic oil and R-134a/P0E oil liquid mixtures.

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An investigation on the in si·tu measurement of the oil-concentration with densimeter (밀도계를 이용한 비추출식 냉동기유농도 측정에 관한 연구)

  • Kim, S.H.;Kim, C.N.;Park, Y.M.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.1
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    • pp.31-37
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    • 1999
  • In order to predict thermodynamic performance of refrigeration system, it is required to know the oil concentration of the refrigerant/oil mixture. The current method to measure the oil concentration is to extract the working mixture and then to measure the oil weight. However, it is Quite necessary to estimate oil concentration without any extraction of the working fluid. In this study a new method and working equation is presented as follows. It is based on the measurement of spedific gravity and temperature : $$C=a+b{\times}t+c{\times}t^2+(d+e{\times}t+f{\times}t^2){\times}SG$$ C is oil concentration, t is temperature($^{\circ}C$), SG is specific gravity of mixture and a~f is coefficients. The oil concentration ranges over 0~12 wt% and the temperature ranges over $20{\sim}50^{\circ}C$. The specific gravity and temperature are measured using the on-line densimeter and thermometer. This working equation enables to predict the oil concentration without any extraction of the mixture. This equation can be applied for R-12/Naphthenic oil and R-134a/POE oil oiquid mixtures.

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An investigation on the in si.tu measurement of the oil-concentration

  • Kim, Chang-Nyeun;Park, Young-Moo
    • International Journal of Air-Conditioning and Refrigeration
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    • v.8 no.2
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    • pp.80-88
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    • 2000
  • In order to predict thermodynamic performance of refrigeration system, it is required to know the oil concentration of the refrigerant/oil mixture. The current method is to extract the working mixture and then to measure the oil weight. In this study, oil concentration is measured in si.tu way without any extraction of the working fluid. Based on the measurement, a working equation is presented as follows, C=a +b x t +c x $t^2$ +(d + e x t +f x $t^2$) x SG. C is oil concentration, t is temperature($^{\circ}C). SG Is specific gravity of mixture and a~f is coefficients The oil concentration ranges over 0~l2 wt% and the temperature ranges over 20~50$^{\circ}C. The specific gravity and temperature are measured using the on-line densimeter and thermometer. This working equation enables to predict the oil concentration without any extraction of the mixture. This equation can be applied for R-12/Naphthenic oil and R-134a/P0E oil liquid mixtures.

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INTERPRETATION OF ELECTROCHEMICAL NOISE PARAMETERS AS INDICATORS OF INITIATION AND PROPAGATION OF SCC OF AN ALLOY 600 SG TUBE AT HIGH TEMPERATURES

  • Kim, Sung-Woo;Kim, Hong-Pyo
    • Nuclear Engineering and Technology
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    • v.41 no.10
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    • pp.1315-1322
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    • 2009
  • The present article is concerned with the application of an electrochemical noise (EN) monitoring technique to analyze the initiation and propagation of Pb-assisted stress corrosion cracking (SCC) of an Alloy 600 material in a simulated environment of a steam generator (SG) sludge pile at high temperatures. A typical increase of electrochemical current noise (ECN) and electrochemical potential noise (EPN) was frequently recorded from the EN measurement in a caustic solution with such impurities as PbO and CuO, indicating that there are localized corrosion events occurring. With the aid of microscopic and spectral analyses, the EN data involving information on such stochastic processes as uniform corrosion and the initiation and propagation of SCC, were analyzed based on a stochastic theory.

Establishment of strain measurement system for evaluation of strain effect in HTS tapes under magnetic field

  • Dedicatoria, Marlon J.;Shin, Hyung-Seop
    • Progress in Superconductivity and Cryogenics
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    • v.13 no.4
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    • pp.14-17
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    • 2011
  • The evaluation of the electromechanical properties of HTS CC tapes is one of the foremost procedures to be done to ensure the applicability of superconducting wires to electric devices. A precise measurement of the stress and strain is important in deriving the mechanical properties under operating environment. Up to now, there is no standard test method yet for the electromechanical property evaluation of HTS tapes under self field and external magnetic field although there are already reports on the different devices used to evaluate these properties. Strain can be measured by adopting a strain gauge or a high resolution double extensometer. In this study, strain effect on $I_c$ in HTS CC tapes under magnetic fields was evaluated. Comparison of advantages and setback of strain measuring devices were discussed. In addition, a dual strain measurement system using both the SG and extensometer may be practical to lessen the burden in case one of the measuring devices does not work well.

Development of Intelligent AMI Sensing Technique Using ICT (기존 전력량계를 ICT 기반 지능형 AMI 센싱 장치로 변환 연구)

  • Sang-Ok Yoon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.18 no.1
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    • pp.23-28
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    • 2023
  • The installation rate of AMI(: Advanced Metering Infrastructure) capable of automatic electricity measurement is less than 43% nationwide and 10.5% in rural areas, which is very poor. Therefore, for the smart grid, automatic information recording of the watt-hour meter is required. For this purpose, it is necessary to develop a system capable of remote meter reading and use control by improving the existing watt-hour meter. In this paper, in order to enable the AMI function of the existing electricity meter, the remote meter reading and control technology of the existing electricity meter for AMI, the core of the smart grid, was developed using IoT and AI. The main research content was to recognize numbers using Tensorflow and Open-cv to convert it into a power meter sensing device for SG. We confirmed and checked the performance using the protyope system.

Development of Intelligent AMI Sensing Technique Using ICT (기존 전력량계를 ICT 기반 지능형 AMI 센싱 장치로 변환 연구)

  • Lee, Yang-weon;Ok, Youn-sang
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2022.10a
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    • pp.546-549
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    • 2022
  • The installation rate of AMI (advanced metering infrastructure) capable of automatic electricity measurement is less than 43% nationwide and 10.5% in rural areas, which is very poor. Therefore, for the smart grid, automatic information recording of the watt-hour meter is required. For this purpose, it is necessary to develop a system capable of remote meter reading and use control by improving the existing watt-hour meter. In this paper, in order to enable the AMI function of the existing electricity meter, the remote meter reading and control technology of the existing electricity meter for AMI, the core of the smart grid, was developed using IoT and AI. The main research content was to recognize numbers using Tensorflow and Open-cv to convert it into a power meter sensing device for SG. We confirmed and checked the performance using the protyope system.

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Using SG Arrays for Hydrology in Comparison with GRACE Satellite Data, with Extension to Seismic and Volcanic Hazards

  • Crossley David;Hinderer Jacques
    • Korean Journal of Remote Sensing
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    • v.21 no.1
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    • pp.31-49
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    • 2005
  • We first review some history of the Global Geodynamics Project (GGP), particularly in the progress of ground-satellite gravity comparisons. The GGP Satellite Project has involved the measurement of ground-based superconducting gravimeters (SGs) in Europe for several years and we make quantitative comparisons with the latest satellite GRACE data and hydrological models. The primary goal is to recover information about seasonal hydrology cycles, and we find a good correlation at the microgal level between the data and modeling. One interesting feature of the data is low soil moisture resulting from the European heat wave in 2003. An issue with the ground-based stations is the possibility of mass variations in the soil above a station, and particularly for underground stations these have to be modeled precisely. Based on this work with a regional array, we estimate the effectiveness of future SG arrays to measure co-seismic deformation and silent-slip events. Finally we consider gravity surveys in volcanic areas, and predict the accuracy in modeling subsurface density variations over time periods from months to years.