• Title/Summary/Keyword: Current detection

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Enzyme Based Biosensors for Detection of Environmental Pollutants-A Review

  • Nigam, Vinod Kumar;Shukla, Pratyoosh
    • Journal of Microbiology and Biotechnology
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    • v.25 no.11
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    • pp.1773-1781
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    • 2015
  • Environmental security is one of the major concerns for the safety of living organisms from a number of harmful pollutants in the atmosphere. Different initiatives, legislative actions, as well as scientific and social concerns have been discussed and adopted to control and regulate the threats of environmental pollution, but it still remains a worldwide challenge. Therefore, there is a need for developing certain sensitive, rapid, and selective techniques that can detect and screen the pollutants for effective bioremediation processes. In this perspective, isolated enzymes or biological systems producing enzymes, as whole cells or in immobilized state, can be used as a source for detection, quantification, and degradation or transformation of pollutants to non-polluting compounds to restore the ecological balance. Biosensors are ideal for the detection and measurement of environmental pollution in a reliable, specific, and sensitive way. In this review, the current status of different types of microbial biosensors and mechanisms of detection of various environmental toxicants are discussed.

Malfunction detection in plasma etching process using EPD signal trace (EPD 신호검출에 의한 플라즈마식각공정의 이상검출)

  • 이종민;차상엽;최순혁;우광방
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1360-1363
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    • 1996
  • EPD(End Point Detection) is used to decide etching degree of layer which must be removed at wafer etching process in plasma etching process which is one of the most important process in semiconductor manufacturing. In this thesis, the method which detects malfunction of etching process in real-time will be discussed. Several EPD signal traces are collected in normal plasma etching condition and used as reference EPD signal traces. Critical points can be detected by applying differentiation and zero-crossing techniques to reference EPD signal. Mean and standard deviation of critical parameters which is memorized from reference EPD signal are calculated and these determine the lower and higher limit of control chart. And by applying statical control chart to EPD signals which are collected in real etching process malfunctions of process are detected in real-time. By means of applying this method to the real etching process we prove our method can accurately detect the malfunction of etching process and can compensate disadvantage of current industrial method.

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Winding Turn-to-Turn Faults Detection of Fault-Tolerant Permanent-Magnet Machines Based on a New Parametric Model

  • Liu, Guohai;Tang, Wei;Zhao, Wenxiang
    • Journal of international Conference on Electrical Machines and Systems
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    • v.2 no.1
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    • pp.23-30
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    • 2013
  • This paper proposes a parametric model for inter-turn fault detection in a fault-tolerant permanent-magnet (FTPM) machine, which can predict the effect of the short-circuit fault to various physical quantity of the machine. For different faulty operations, a new effective stator inter-turn fault detection method is proposed. Finally, simulations of vector-controlled FTPM machine drives are given to verify the feasibility of the proposed method, showing that even single-coil short-circuit fault could be exactly detected.

A Matlab and Simulink Based Three-Phase Inverter Fault Diagnosis Method Using Three-Dimensional Features

  • Talha, Muhammad;Asghar, Furqan;Kim, Sung Ho
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.16 no.3
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    • pp.173-180
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    • 2016
  • Fault detection and diagnosis is a task to monitor the occurrence of faults and pinpoint the exact location of faults in the system. Fault detection and diagnosis is gaining importance in development of efficient, advanced and safe industrial systems. Three phase inverter is one of the most common and excessively used power electronic system in industries. A fault diagnosis system is essential for safe and efficient usage of these inverters. This paper presents a fault detection technique and fault classification algorithm. A new feature extraction approach is proposed by using three-phase load current in three-dimensional space and neural network is used to diagnose the fault. Neural network is responsible of pinpointing the fault location. Proposed method and experiment results are presented in detail.

Nanoparticle-based Detection Technology for DNA Analysis

  • Park, Hyun-Gyu
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.8 no.4
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    • pp.221-226
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    • 2003
  • With the current rapid development of nanotechnology and synthesis technology for designed oligonucleotides or oligonucleotide-modified nanoparticle conjugates, the combined strategies have become one of the most valuable methods in detection technology for DNA analysis. Using the uniquely recognizable interactions of pre-designed DNA molecules in assembling nanoparticles, various novel approaches have been recently developed towards detecting specific DNA sequences. Here we describe the key fundamentals and issues of this promising strategies ranging from the initial findings of rationally designed DNA-based assembly of nanoparticles to the extended chip-based detection system. Some limitations of these new strategies and possible approaches will be also discussed for the practical application in the area of DNA microarray detection.

Detection of Input Voltage Unbalance in Induction Motors Using Frequency-Domain Discrete Wavelet Transform

  • Ghods, Amirhossein;Lee, Hong-Hee;Chun, Tae-Won
    • Proceedings of the KIPE Conference
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    • 2014.07a
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    • pp.522-523
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    • 2014
  • Analysis of faults in induction motors has become a major field of research due to importance of loss and damage reduction and maximum online performance of motors. There are several methods to analyze the faults in an induction motor from conventional Fourier transform to modern decision-making neural networks. Considering detectability of fault among all methods, a new fault detection solution has been proposed; it is called as frequency-domain Discrete Wavelet Transform (FD-DWT). In this method, the stator current is decomposed through series of low- and high-pass filters and consequently, the fault characteristics are more visible, because additional components have been reduced. The objective of this paper is early detection of input voltage unbalance in induction motor using wavelet transform in frequency domain. Experimental results show the effectiveness of the proposed method in early detection of faults.

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Road Damage Detection and Classification based on Multi-level Feature Pyramids

  • Yin, Junru;Qu, Jiantao;Huang, Wei;Chen, Qiqiang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.2
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    • pp.786-799
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    • 2021
  • Road damage detection is important for road maintenance. With the development of deep learning, more and more road damage detection methods have been proposed, such as Fast R-CNN, Faster R-CNN, Mask R-CNN and RetinaNet. However, because shallow and deep layers cannot be extracted at the same time, the existing methods do not perform well in detecting objects with fewer samples. In addition, these methods cannot obtain a highly accurate detecting bounding box. This paper presents a Multi-level Feature Pyramids method based on M2det. Because the feature layer has multi-scale and multi-level architecture, the feature layer containing more information and obvious features can be extracted. Moreover, an attention mechanism is used to improve the accuracy of local boundary boxes in the dataset. Experimental results show that the proposed method is better than the current state-of-the-art methods.

On-line Shared Platform Evaluation Framework for Advanced Persistent Threats

  • Sohn, Dongsik;Lee, Taejin;Kwak, Jin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.5
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    • pp.2610-2628
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    • 2019
  • Advanced persistent threats (APTs) are constant attacks of specific targets by hackers using intelligent methods. All current internal infrastructures are constantly subject to APT attacks created by external and unknown malware. Therefore, information security officers require a framework that can assess whether information security systems are capable of detecting and blocking APT attacks. Furthermore, an on-line evaluation of information security systems is required to cope with various malicious code attacks. A regular evaluation of the information security system is thus essential. In this paper, we propose a dynamic updated evaluation framework to improve the detection rate of internal information systems for malware that is unknown to most (over 60 %) existing static information security system evaluation methodologies using non-updated unknown malware.

Network intrusion detection method based on matrix factorization of their time and frequency representations

  • Chountasis, Spiros;Pappas, Dimitrios;Sklavounos, Dimitris
    • ETRI Journal
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    • v.43 no.1
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    • pp.152-162
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    • 2021
  • In the last few years, detection has become a powerful methodology for network protection and security. This paper presents a new detection scheme for data recorded over a computer network. This approach is applicable to the broad scientific field of information security, including intrusion detection and prevention. The proposed method employs bidimensional (time-frequency) data representations of the forms of the short-time Fourier transform, as well as the Wigner distribution. Moreover, the method applies matrix factorization using singular value decomposition and principal component analysis of the two-dimensional data representation matrices to detect intrusions. The current scheme was evaluated using numerous tests on network activities, which were recorded and presented in the KDD-NSL and UNSW-NB15 datasets. The efficiency and robustness of the technique have been experimentally proved.

Abnormal Crowd Behavior Detection Using Heuristic Search and Motion Awareness

  • Usman, Imran;Albesher, Abdulaziz A.
    • International Journal of Computer Science & Network Security
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    • v.21 no.4
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    • pp.131-139
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    • 2021
  • In current time, anomaly detection is the primary concern of the administrative authorities. Suspicious activity identification is shifting from a human operator to a machine-assisted monitoring in order to assist the human operator and react to an unexpected incident quickly. These automatic surveillance systems face many challenges due to the intrinsic complex characteristics of video sequences and foreground human motion patterns. In this paper, we propose a novel approach to detect anomalous human activity using a hybrid approach of statistical model and Genetic Programming. The feature-set of local motion patterns is generated by a statistical model from the video data in an unsupervised way. This features set is inserted to an enhanced Genetic Programming based classifier to classify normal and abnormal patterns. The experiments are performed using publicly available benchmark datasets under different real-life scenarios. Results show that the proposed methodology is capable to detect and locate the anomalous activity in the real time. The accuracy of the proposed scheme exceeds those of the existing state of the art in term of anomalous activity detection.