• Title/Summary/Keyword: abnormality detection system

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Cloud-based malware QR Code detection system (클라우드 기반 악성 QR Code 탐지 시스템)

  • Kim, Dae-Woon;Jo, Young-Tae;Kim, Jong-Min
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.9
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    • pp.1227-1233
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    • 2021
  • QR Code has been used in various forms such as simple business cards and URLs. Recently, the influence of Corona 19 Fundemik has led to the use of QR Codes to track travel routes through visits and entry / exit records, and QR Code usage has skyrocketed. In this way, most people have come to use it in the masses and are constantly under threat. In the case of QR Code, you do not know what you are doing until you execute it. Therefore, if you undoubtedly execute a QR Code with a malicious URL inserted, you will be directly exposed to security threats. Therefore, this paper provides a cloud-based malware QR Code detection system that can make a normal connection only when there is no abnormality after determining whether it is a malicious QR Code when scanning the QR Code.

Anomaly Detection for User Action with Generative Adversarial Networks (적대적 생성 모델을 활용한 사용자 행위 이상 탐지 방법)

  • Choi, Nam woong;Kim, Wooju
    • Journal of Intelligence and Information Systems
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    • v.25 no.3
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    • pp.43-62
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    • 2019
  • At one time, the anomaly detection sector dominated the method of determining whether there was an abnormality based on the statistics derived from specific data. This methodology was possible because the dimension of the data was simple in the past, so the classical statistical method could work effectively. However, as the characteristics of data have changed complexly in the era of big data, it has become more difficult to accurately analyze and predict the data that occurs throughout the industry in the conventional way. Therefore, SVM and Decision Tree based supervised learning algorithms were used. However, there is peculiarity that supervised learning based model can only accurately predict the test data, when the number of classes is equal to the number of normal classes and most of the data generated in the industry has unbalanced data class. Therefore, the predicted results are not always valid when supervised learning model is applied. In order to overcome these drawbacks, many studies now use the unsupervised learning-based model that is not influenced by class distribution, such as autoencoder or generative adversarial networks. In this paper, we propose a method to detect anomalies using generative adversarial networks. AnoGAN, introduced in the study of Thomas et al (2017), is a classification model that performs abnormal detection of medical images. It was composed of a Convolution Neural Net and was used in the field of detection. On the other hand, sequencing data abnormality detection using generative adversarial network is a lack of research papers compared to image data. Of course, in Li et al (2018), a study by Li et al (LSTM), a type of recurrent neural network, has proposed a model to classify the abnormities of numerical sequence data, but it has not been used for categorical sequence data, as well as feature matching method applied by salans et al.(2016). So it suggests that there are a number of studies to be tried on in the ideal classification of sequence data through a generative adversarial Network. In order to learn the sequence data, the structure of the generative adversarial networks is composed of LSTM, and the 2 stacked-LSTM of the generator is composed of 32-dim hidden unit layers and 64-dim hidden unit layers. The LSTM of the discriminator consists of 64-dim hidden unit layer were used. In the process of deriving abnormal scores from existing paper of Anomaly Detection for Sequence data, entropy values of probability of actual data are used in the process of deriving abnormal scores. but in this paper, as mentioned earlier, abnormal scores have been derived by using feature matching techniques. In addition, the process of optimizing latent variables was designed with LSTM to improve model performance. The modified form of generative adversarial model was more accurate in all experiments than the autoencoder in terms of precision and was approximately 7% higher in accuracy. In terms of Robustness, Generative adversarial networks also performed better than autoencoder. Because generative adversarial networks can learn data distribution from real categorical sequence data, Unaffected by a single normal data. But autoencoder is not. Result of Robustness test showed that he accuracy of the autocoder was 92%, the accuracy of the hostile neural network was 96%, and in terms of sensitivity, the autocoder was 40% and the hostile neural network was 51%. In this paper, experiments have also been conducted to show how much performance changes due to differences in the optimization structure of potential variables. As a result, the level of 1% was improved in terms of sensitivity. These results suggest that it presented a new perspective on optimizing latent variable that were relatively insignificant.

Wear Characteristic of Diamond Burs in Dentistry (치과용 다이아몬드 버의 마멸 특성)

  • 이근상;임영호;권동호;최만용;김교한;최영윤
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.80-84
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    • 1996
  • This paper aims at reviewing the Possibility application over normal or abnormal, detection used by AE and the wear characteristics of grinding process. In this study, when diamond bur in dentistry with chosen grinding conditions were tuned at grinding. The variation of grinding resistance and hE signal is detected by the use of AE measuring system. The tests are carried out in accordance with diamond burs and workpiece; arcyl and bovine. According to the experiment results, the following can be expected; AE has the possibility to detect the state normality and abnormality. However, the grinding resistance measuring can find it difficult to detect it. It can be accurately excerpted from AE occurrence pattern in contact start point of diamond bur and bovine, grinding condition and derailment point. It is known that AE$\_$rms/ is well compatible with grinding resistance. According to the increase of the material removal rate, the specific energy of the diamond bur is inclined to decrease and the grinding resistance has a tendency to increase.

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Anomaly Diagnosis of Rotational Machinery Using Time-Series Vibration Data Based on Time-Distributed CNN-LSTM (시분할 CNN-LSTM 기반의 시계열 진동 데이터를 이용한 회전체 기계 설비의 이상 진단)

  • Kim, Min-Ki
    • Journal of Korea Multimedia Society
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    • v.25 no.11
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    • pp.1547-1556
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    • 2022
  • As mechanical facilities are interacting with each other, the failure of some equipment can affect the entire system, so it is necessary to quickly detect and diagnose the abnormality of mechanical equipment. This study proposes a deep learning model that can effectively diagnose abnormalities in rotating machinery and equipment. CNN is widely used for feature extraction and LSTMs are known to be effective in learning sequential information. In LSTM, the number of parameters and learning time increase as the length of input data increases. In this study, we propose a method of segmenting an input segment signal into shorter-length sub-segment signals, sequentially inputting them to CNN through a time-distributed method for extracting features, and inputting them into LSTM. A failure diagnosis test was performed using the vibration data collected from the motor for ventilation equipment installed at the urban railway station. The experiment showed an accuracy of 99.784% in fault diagnosis. It shows that the proposed method is effective in the fault diagnosis of rotating machinery and equipment.

Grinding Characteristics of Diamond Burs in Dentistry (치과용 다이아몬드 버의 연삭가공 특성)

  • Lee, Keun-Sang;Lim, Young-Ho;Kwon, Dong-Ho;Choi, Man-Yong;Kim, Kyo-Han;Choi, Young-Yun
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.12
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    • pp.66-72
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    • 1997
  • This paper aims at reviewing the possibility application over normal or abnormal, detection used by AE and the wear characteristics of grinding process. In this study, when diamond bur in dentistry with chosen grinding conditions were tuned at grinding. The variation of grinding resistance and AE signal is detected by the use of AE measuring system. The tests are carried out in accordance with diamond burs and workpiece: arcyl and bovine. According to the experiment results, the following can be expected: AE has the possibility to detect the state normality and abnormality. Hpwever, the grinding resistance measuring can find it difficult to detect it. It can be accurately excepted from AE occurrence pattern in contact start point of diamond bur and bovine, grinding condition and derailment point. It is known that AErms is well compatible with grinding resistance. According to the increase of the material removal rate, the specific energy of the diamond bur is inclined to dectease and the grinding resistance has a tendency to increase.

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Process Fault Probability Generation via ARIMA Time Series Modeling of Etch Tool Data

  • Arshad, Muhammad Zeeshan;Nawaz, Javeria;Park, Jin-Su;Shin, Sung-Won;Hong, Sang-Jeen
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.241-241
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    • 2012
  • Semiconductor industry has been taking the advantage of improvements in process technology in order to maintain reduced device geometries and stringent performance specifications. This results in semiconductor manufacturing processes became hundreds in sequence, it is continuously expected to be increased. This may in turn reduce the yield. With a large amount of investment at stake, this motivates tighter process control and fault diagnosis. The continuous improvement in semiconductor industry demands advancements in process control and monitoring to the same degree. Any fault in the process must be detected and classified with a high degree of precision, and it is desired to be diagnosed if possible. The detected abnormality in the system is then classified to locate the source of the variation. The performance of a fault detection system is directly reflected in the yield. Therefore a highly capable fault detection system is always desirable. In this research, time series modeling of the data from an etch equipment has been investigated for the ultimate purpose of fault diagnosis. The tool data consisted of number of different parameters each being recorded at fixed time points. As the data had been collected for a number of runs, it was not synchronized due to variable delays and offsets in data acquisition system and networks. The data was then synchronized using a variant of Dynamic Time Warping (DTW) algorithm. The AutoRegressive Integrated Moving Average (ARIMA) model was then applied on the synchronized data. The ARIMA model combines both the Autoregressive model and the Moving Average model to relate the present value of the time series to its past values. As the new values of parameters are received from the equipment, the model uses them and the previous ones to provide predictions of one step ahead for each parameter. The statistical comparison of these predictions with the actual values, gives us the each parameter's probability of fault, at each time point and (once a run gets finished) for each run. This work will be extended by applying a suitable probability generating function and combining the probabilities of different parameters using Dempster-Shafer Theory (DST). DST provides a way to combine evidence that is available from different sources and gives a joint degree of belief in a hypothesis. This will give us a combined belief of fault in the process with a high precision.

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Decentralized Structural Diagnosis and Monitoring System for Ensemble Learning on Dynamic Characteristics (동특성 앙상블 학습 기반 구조물 진단 모니터링 분산처리 시스템)

  • Shin, Yoon-Soo;Min, Kyung-Won
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.34 no.4
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    • pp.183-189
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    • 2021
  • In recent years, active research has been devoted toward developing a monitoring system using ambient vibration data in order to quantitatively determine the deterioration occurring in a structure over a long period of time. This study developed a low-cost edge computing system that detects the abnormalities in structures by utilizing the dynamic characteristics acquired from the structure over the long term for ensemble learning. The system hardware consists of the Raspberry Pi, an accelerometer, an inclinometer, a GPS RTK module, and a LoRa communication module. The structural abnormality detection afforded by the ensemble learning using dynamic characteristics is verified using a laboratory-scale structure model vibration experiment. A real-time distributed processing algorithm with dynamic feature extraction based on the experiment is installed on the Raspberry Pi. Based on the stable operation of installed systems at the Community Service Center, Pohang-si, Korea, the validity of the developed system was verified on-site.

Role of Magnetocardiography in Emergency Room (응급실에서 심자도의 역할)

  • Kwon, H.;Kim, K.;Kim, J.M.;Lee, Y.H.;Kim, T.E.;Lim, H.K.;Park, Y.K.;Ko, Y.G.;Chung, N.
    • Progress in Superconductivity
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    • v.8 no.1
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    • pp.40-45
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    • 2006
  • In emergency rooms, patients with acute chest pain should be diagnosed as quickly as possible with higher diagnostic accuracy for an appropriate therapy to the patients with acute coronary syndrome or for avoiding unnecessary hospital admissions. At present, electrocardiography(ECG) and biochemical markers are generally used to detect myocardial infarction and coronary angiography is used as a gold standard to reveal the degree of narrowing of coronary artery. Magnetocardiography(MCG) has been proposed as a novel and non-invasive diagnostic tool fur the detection of cardiac electrical abnormality associated with myocardial ischemia. In this study, we examined whether the MCG can be used fur the detection of coronary artery disease(CAD) in patients, who were admitted to the emergency room with acute chest pain. MCG was recorded from 36 patients admitted to the emergency room with suspected acute coronary syndrome. The MCG recordings were obtained using a 64-channel SQUID MCG system in a magnetically shielded room. In result, presence of CAD could be found with a sensitivity of 88.2 % in patients with acute chest pain without 57 elevation in ECG, demonstrating a possible use in the emergency room to screen CAD patients.

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Anomaly Detections Model of Aviation System by CNN (합성곱 신경망(CNN)을 활용한 항공 시스템의 이상 탐지 모델 연구)

  • Hyun-Jae Im;Tae-Rim Kim;Jong-Gyu Song;Bum-Su Kim
    • Journal of Aerospace System Engineering
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    • v.17 no.4
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    • pp.67-74
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    • 2023
  • Recently, Urban Aircraft Mobility (UAM) has been attracting attention as a transportation system of the future, and small drones also play a role in various industries. The failure of various types of aviation systems can lead to crashes, which can result in significant property damage or loss of life. In the defense industry, where aviation systems are widely used, the failure of aviation systems can lead to mission failure. Therefore, this study proposes an anomaly detection model using deep learning technology to detect anomalies in aviation systems to improve the reliability of development and production, and prevent accidents during operation. As training and evaluating data sets, current data from aviation systems in an extremely low-temperature environment was utilized, and a deep learning network was implemented using the convolutional neural network, which is a deep learning technique that is commonly used for image recognition. In an extremely low-temperature environment, various types of failure occurred in the system's internal sensors and components, and singular points in current data were observed. As a result of training and evaluating the model using current data in the case of system failure and normal, it was confirmed that the abnormality was detected with a recall of 98 % or more.

Development of Monitoring System for the LNG plant fractionation process based on Multi-mode Principal Component Analysis (다중모드 주성분분석에 기반한 천연가스 액화플랜트의 성분 분리공정 감시 시스템 개발)

  • Pyun, Hahyung;Lee, Chul-Jin;Lee, Won Bo
    • Journal of the Korean Institute of Gas
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    • v.23 no.4
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    • pp.19-27
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    • 2019
  • The consumption of liquefied natural gas (LNG) has increased annually due to the strengthening of international environmental regulations. In order to produce stable and efficient LNG, it is essential to divide the global (overall) operating condition and construct a quick and accurate monitoring system for each operation condition. In this study, multi-mode monitoring system is proposed to the LNG plant fractionation process. First, global normal operation data is divided to local (subdivide) normal operation data using global principal component analysis (PCA) and k-means clustering method. And then, the data to be analyzed were matched with the local normal mode. Finally, it is determined the state of process abnormality through the local PCA. The proposed method is applied to 45 fault case and it proved to be more than 5~10% efficient compared to the global PCA and univariate monitoring.