• Title/Summary/Keyword: Abnormal signal

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A Study on a Healthcare System Using Smart Clothes

  • Lim, Chae Young;Kim, Kyungho
    • Journal of Electrical Engineering and Technology
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    • v.9 no.1
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    • pp.372-377
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    • 2014
  • Being able to monitor the heart will allow the diagnosis of heart diseases for patients during daily activities, and the detection of burden on the heart during strenuous exercise. Furthermore, with the help of U-health technology, immediate medical action can be taken, in the case of abnormal symptoms of the heart in daily life. Therefore, it appears to be necessary to develop the corresponding technology to monitor the condition of the heart daily. In this study, a novel wearable smart system was proposed, to monitor the activity of the heart in daily life, and to further evaluate the rhythm of arrhythmia. The wearable system includes three modified bipolar conductive fiber electrodes in the chest part, which can resolve the reduction problem of the magnitude of the signal, by magnifying the signal and removing the noise, to obtain high affinity and validity for medical-type usage (<0.903%). The biological signal acquisition and data lines, and the signal processing engine and communication consist of a conductive ink, and the pic18 and ANT protocol nRF24AP2, respectively. The proposed algorithm was able to detect a strong ECG, signal and r-point passing over the noise. The confidence intervals were 96 %, which could satisfy the requirement to detect arrhythmia under the unconstrained conditions.

Development of Fault Prediction System Using Peak-code Method in Power Plants (피크코드 기법을 이용한 발전설비 고장예측 시스템 개발)

  • Roh, Chang-Su;Do, Sung-Chan;Chong, Ui-Pil
    • Journal of the Institute of Convergence Signal Processing
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    • v.9 no.4
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    • pp.329-336
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    • 2008
  • The facilities with new technologies in the recent power plants become larger and need a lot of high cost for maintenance due to stop operations and accidents from the operating machines. Therefore, it claims new systems to monitor the operating status and predict the faults of the machines. This research classifies the normal/abnormal status of the machines into 5 levels which are normal-level/abnormal-level/care-level/dangerous-level/fault and develops the new system that predicts faults without stop operation in power plants. We propose the regional segmentation technique in the frequency domain from the data of the operating machines and generate the Peak-codes similar to the Bar-codes, The high efficient and economic operations of the power plants will be achieved by carrying out the pre-maintenance at the care level of 5 levels in the plants. In order to be utilized easily at power plants, we developed the algorithm appling to a notebook computer from signal acquisition to the discrimination.

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Monitoring of Machining State in Turning by Means of Information and Feed Motor Current (NC 정보와 이송축 모터 전류를 이용한 선삭 가공 상태 감시)

  • 안중환;김화영
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.1
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    • pp.156-161
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    • 1992
  • In this research a monitoring system for turning using NC information and the current of feed motor as a monitoring signal was developed. The overall system consists of modules such as learning process, NC data transmission, generation of forecast information, signal acquisition, monitoring and post process. In the learning process, the reference data and the cutting force equation necessary for monitoring are obtained from the accumulated monitoring results. In the generation of forecast information, the information of forecasted cutting forces is acquired from the cutting force equation and NC program and appended to each NC block as a monitor code. Reliability of monitoring is improved by using the monitor code in the real-time monitoring. Monitoring module is divided into two parts : the off-line monitoring where errors of NC program are checked and the on-line monitoring where the level of motor current is monitored during cutting operations. If the actual current level exceeds the limit value provided by the monitor code in the level monitoring, it is recognized as abnormal. In the event of abnormal status, the post processor sends the emergency stop signal to NC controller to stop the operation. Actual experiments have shown that the developed monitoring system works well.

RF Seeker LOS Rate Estimation Method using Covariance and Signal Management (공분산 및 신호관리를 이용한 RF탐색기 시선각 변화율 추정기법)

  • Moon, Gwan-Young;Jun, Byung-Eul
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.4
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    • pp.292-299
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    • 2012
  • The line-of-sight(LOS) rate is estimated using Kalman filter in Radio-Frequency(RF) seeker. For the two axis gimbaled seeker, proper system modeling is considered and the basic filter structure is set up. The main issue for Kalman filter is choosing the proper process and measurement noise. For the measurement process, the signal to noise ratio(SNR) and other components are introduced. To cope with the eclipse problem or other abnormal seeker status, the pseudo input signal concept is proposed. By conditioning abnormal signals, the LOS rate estimation performance is increased. The process noise is also an important factor in the propagation phase. The analytical approach on a process noise component is performed and a reliable region for the filter is calculated based on the eigenvalue analysis. Some numerical simulations are performed to check the validity of suggested algorithm.

Acute High-Altitude Cerebral Edema Presenting as Extensive Microbleeds along the Corpus Callosum without T2 Hyperintensity: A Case Report and Literature Review (T2 고신호강도가 동반되지 않은 뇌량의 광범위한 미세출혈의 형태로 나타난 고산병: 증례 보고 및 문헌 고찰)

  • Jin Young Son;Jee Young Kim;Sanghyuk Im
    • Journal of the Korean Society of Radiology
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    • v.82 no.4
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    • pp.953-958
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    • 2021
  • High-altitude cerebral edema (HACE) is a potentially fatal neurological syndrome that develops in persons traveling to a high altitude. We report the case of a 49-year-old male who had traveled to a high altitude, and lost consciousness for a few hours. Susceptibility-weighted images revealed multiple, fine black pepper like microbleeds along the corpus callosum with several microbleeds in the left frontal and parietal subcortical white matter. The T2-weighted images did not show any abnormal signal intensities along the corpus callosum. The diffusion-weighted images revealed small nodular high signal intensities in the basal ganglia. This report describes the atypical radiologic findings of HACE showing multiple microbleeds along the corpus callosum, without abnormal high-signal intensity on T2-weighted images.

Evaluation by Contrast-Enhanced MR Imaging of the Lateral Border Zone in Reperfused Myocardial Infarction in a Cat Model

  • Ae Kyung Jeong;Sang Il Choi;Dong Hun Kim;Sung Bin Park;Seoung Soo Lee;Seong Hoon Choi;Tae-Hwan Lim
    • Korean Journal of Radiology
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    • v.2 no.1
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    • pp.21-27
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    • 2001
  • Objective: To identify and evaluate the lateral border zone by comparing the size and distribution of the abnormal signal area demonstrated by MR imaging with the infarct area revealed by pathological examination in a reperfused myocardial infarction cat model. Materials and Methods: In eight cats, the left anterior descending coronary artery was occluded for 90 minutes, and this was followed by 90 minutes of reperfusion. ECG-triggered breath-hold turbo spin-echo T2-weighted MR images were initially obtained along the short axis of the heart before the administration of contrast media. After the injection of Gadomer-17 and Gadophrin-2, contrast-enhanced T1-weighted MR images were obtained for three hours. The size of the abnormal signal area seen on each image was compared with that of the infarct area after TTC staining. To assess ultrastructural changes in the myocardium at the infarct area, lateral border zone and normal myocardium, electron microscopic examination was performed. Results: The high signal area seen on T2-weighted images and the enhanced area seen on Gadomer-17-enhanced T1WI were larger than the enhanced area on Gadophrin-2-enhanced T1WI and the infarct area revealed by TTC staining; the difference was expressed as a percentage of the size of the total left ventricle mass (T2= 39.2 %; Gadomer-17 =37.25 % vs Gadophrin-2 = 29.6 %; TTC staining = 28.2 %; p < 0.05). The ultrastructural changes seen at the lateral border zone were compatible with reversible myocardial damage. Conclusion: In a reperfused myocardial infarction cat model, the presence and size of the lateral border zone can be determined by means of Gadomer-17- and Gadophrin-2-enhanced MR imaging.

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Development of Hardware for Controlling Abnormal Temperature in PCS of Photovoltaic System (태양광발전시스템의 PCS에서 이상 온도 제어를 위한 하드웨어개발)

  • Kim, Doo-Hyun;Kim, Sung-Chul;Kim, Yoon-Bok
    • Journal of the Korean Society of Safety
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    • v.34 no.1
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    • pp.21-26
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    • 2019
  • This paper is purposed to develop hardware for controlling abnormal temperature that can occur environment and component itself in PCS. In order to be purpose, the hardware which is four part(sensing, PLC, monitoring and output) keep detecting temperature for critical components of PCS and can control the abnormal temperature. Apply to the hardware, it is selected to PV power generation facilities of 20 kW in Cheong-ju city and measured the data for one year in 2017. Through the temperature data, it is found critical components of four(discharge resistance, DC capacitor, IGBT, DSP board) and entered the setting value for operating the fan. The setting values for operating the fan are up to $130^{\circ}C$ in discharge resistance, $60^{\circ}C$ in DC capacitor, $55^{\circ}C$ in IGBT and DSP board. The hardware is installed at the same PCS(20 kW in Cheong-ju city) in 2018 and the power generation output is analyzed for the five days with the highest atmospheric temperature(Clear day) in July and August in 2017 and 2018 years. Therefore, the power generation output of the PV system with hardware increased up to 4 kWh.

Improvement of Abnormal Altitude Display of Radar Altimeter by Using Attenuation of Received Interference (수신 간섭의 신호 감쇠를 통한 전파고도계의 비정상 고도 시현 개선)

  • Kwon, Jung-Hyuk;Oh, Seung-Hyun;Seo, Byung-Il;Lee, Wang-Sang
    • Journal of Aerospace System Engineering
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    • v.16 no.2
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    • pp.39-48
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    • 2022
  • The purpose of this paper was to study how to improve the occurrence of abnormal altitude values of radio altimeter, due to RF interference signals during the flight of aircraft. In flight missions, since it performs a roll-out after several high maneuvers, accurate altitude must be displayed to effectively perform flight missions. Thus, a root cause analysis and trouble shooting were performed for the display of abnormal altitude values of radar altimeters, and a method of reducing RF interference signals by installing an attenuator was examined. Additionally, the verification results for the improvements are also described.

A Study on the Detection of the Abnormal Tool State for Neural Network in Drilling (신경망에 의한 공구 이상상태 검출에 관한 연구)

  • Shin, Hyung-Gon;Kim, Tae-Young
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.821-826
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    • 2001
  • Out of all metal-cutting processes, the hole-making process is the most widely used. It is estimated to be more than 30% of the total metal-cutting process. It is therefore desirable to monitor and detect drill wear during the hole-drilling process. One important aspect in controlling the drilling process is monitoring drill wear status. Accordingly, this paper deals with Basic system and Online system. Basic system comprised of spindle rotational speed, feed rates, thrust, torque and flank wear measured tool microscope. Online system comprised of spindle rotational speed, feed rates, AE signal, flank wear area measured computer vision. On-line monitoring system does not need to stop the process to inspect drill wear. Backpropagation neural networks (BPNs) were used for on-line detection of drill wear. This paper deals with an on-line drill wear monitoring system to fit the detection of the abnormal tool state.

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The Abnormal Condition Monitoring of Rotary Compressor using Acoustic Emission (AE 신호를 이용한 회전형 압축기의 이상상태 감시)

  • Lee Kam-Gyu;Jung Ji-Hong;Kim Jeon-Ha;Kang Myung-Chang;Kim Jeong-Suk
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.13 no.5
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    • pp.118-123
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    • 2004
  • The compressor has one of important roles in refrigeration cycle and it determines refrigeration efficiency and quality This paper aims to monitor rotary compressors for room air conditioners by using Acoustic Emission(AE) technique. The reliability of rotary compressors has been evaluated through visual inspection on them after long term test. This paper describes methods for acquisition and processing AE raw signal to monitor the state of rotary compressor. A detecting method of abnormal compressor in real time is suggested and special-purpose monitoring system which can be applied to automatic manufacturing line is developed using one-chip microprocessor at low cost.