• Title/Summary/Keyword: current detection

Search Result 2,519, Processing Time 0.027 seconds

A dynamic procedure for defection detection and prevention based on SOM and a Markov chain

  • Kim, Young-ae;Song, Hee-seok;Kim, Soung-hie
    • Proceedings of the KAIS Fall Conference
    • /
    • 2003.11a
    • /
    • pp.141-148
    • /
    • 2003
  • Customer retention is a common concern for many industries and a critical issue for the survival in today's greatly compressed marketplace. Current customer retention models only focus on detection of potential defectors based on the likelihood of defection by using demographic and customer profile information. In this paper, we propose a dynamic procedure for defection detection and prevention using past and current customer behavior by utilizing SOM and Markov chain. The basic idea originates from the observation that a customer has a tendency to change his behavior (i.e. trim-out his usage volumes) before his eventual withdrawal. This gradual pulling out process offers the company the opportunity to detect the defection signals. With this approach, we have two significant benefits compared with existing defection detection studies. First, our procedure can predict when the potential defectors could withdraw and this feature helps to give marketing managers ample lead-time for preparing defection prevention plans. The second benefit is that our approach can provide a procedure for not only defection detection but also defection prevention, which could suggest the desirable behavior state for the next period so as to lower the likelihood of defection. We applied our dynamic procedure for defection detection and prevention to the online gaming industry. Our suggested procedure could predict potential defectors without deterioration of prediction accuracy compared to that of the MLP neural network and DT.

  • PDF

Data Preprocessing Method for Lightweight Automotive Intrusion Detection System (차량용 경량화 침입 탐지 시스템을 위한 데이터 전처리 기법)

  • Sangmin Park;Hyungchul Im;Seongsoo Lee
    • Journal of IKEEE
    • /
    • v.27 no.4
    • /
    • pp.531-536
    • /
    • 2023
  • This paper proposes a sliding window method with frame feature insertion for immediate attack detection on in-vehicle networks. This method guarantees real-time attack detection by labeling based on the attack status of the current frame. Experiments show that the proposed method improves detection performance by giving more weight to the current frame in CNN computation. The proposed model was designed based on a lightweight LeNet-5 architecture and it achieves 100% detection for DoS attacks. Additionally, by comparing the complexity with conventional models, the proposed model has been proven to be more suitable for resource-constrained devices like ECUs.

Anti-islanding Method by Harmonic Injection for Utility Interactive Inverter with Critical Load (중요부하를 갖는 계통연계형 인버터의 고조파주입에 의한 단독운전방지 기법)

  • Oh, Hyeong-Min;Choi, Se-Wan;Kim, Tae-Hee;Lee, Gi-Pung;Lee, Tae-Won
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.17 no.4
    • /
    • pp.315-321
    • /
    • 2012
  • The utility-interactive inverter with critical loads should supply continuous and stable voltage to critical loads even during the grid fault. The conventional control method which performs current control for grid-connected mode and voltage control for stand-alone mode undergoes the critical load voltage variation during grid fault. The critical load voltage may have large transient when the inverter performs mode transfer after the islanding detection. Recently, the indirect current control method which does not have the transient state during not only islanding detection but also the mode transfer has been proposed. However, since the voltage control is maintained even during the grid-connected mode it is difficult to detect the islanding. This paper proposes an active anti-islanding method suitable for the indirect current control method which does not have NDZ(Non-Detection Zone).

The Space Vector Detection based Three-Phase Hybrid Series Active Power Filter for Compensating Dynamic Voltage Sag and Harmonic Current (순시전압 sag 및 고조파 전류 보상을 위한 공간벡터 검출법 기반의 3상 하이브리드 직렬형 능동전력필터)

  • 양승환;정영국;임영철
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.9 no.4
    • /
    • pp.303-310
    • /
    • 2004
  • In this paper, for compensating dynamic voltage sag and harmonic current, 3-phase hybrid series active power filter based on the space vector detection is proposed. The Space vector algorithm for detecting the voltage sag and the harmonic current in compared with conventional theory is a simple method for calculating the compensating reference without any coordinated transformation. The effectiveness of the proposed system is verified by the PSIM simulation in the steady state and the transient state, which the proposed system is able to simultaneously compensate harmonics and source voltage unbalance / sag.

Fault Detection and Diagnosis of Winding Short in BLDC Motors Based on Fuzzy Similarity

  • Bae, Hyeon;Kim, Sung-Shin;Vachtsevanos, George
    • International Journal of Fuzzy Logic and Intelligent Systems
    • /
    • v.9 no.2
    • /
    • pp.99-104
    • /
    • 2009
  • The turn-to-turn short is one major fault of the motor faults of BLDC motors and can appear frequently. When the fault happens, the motor can be operated without breakdown, but it is necessary to maintain the motor for continuous working. In past research, several methods have been applied to detect winding faults. The representative approaches have been focusing on current signals, which can give important information to extract features and to detect faults. In this study, current sensors were installed to measure signals for fault detection of BLDC motors. In this study, the Park's vector method was used to extract the features and to isolate the faults from the current measured by sensors. Because this method can consider the three-phase current values, it is useful to detect features from one-phase and three-phase faults. After extracting two-dimensional features, the final feature was generated by using the two-dimensional values using the distance equation. The values were used in fuzzy similarity to isolate the faults. Fuzzy similarity is an available tool to diagnose the fault without model generation and the fault was converted to the percentage value that can be considered as possibility of the fault.

A Study on the Detection of Indication of Accident in Electric Equipments with Incandescent Lamps Using Current Monitor (전류 모니터를 이용한 백열등 부하 전기설비에서 사고 징후 검출에 관한 연구)

  • Jee, Seung-Wook;Ok, Kyung-Gea;Kim, Shi-Kuk;Lee, Chun-Ha;Lee, Kwang-Sik
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.23 no.1
    • /
    • pp.109-115
    • /
    • 2009
  • This paper describes an early detection for indication of electric accident using current waveform which is measured in electric equipments consisted incandescent lamps. At first, it analyzes characteristics of current monitor in resistive electric circuit. In second, the electric equipment is consisted of incandescent lamps. And the electric accident is simulation of tracking according to KS C IEC(Korea Standard C International Electrostatic Commission) 60112 at some part of the electric equipment. The indication of the electrical accident is detected to analyzing current waveform measured by current monitor. As the tracking breakdown, electric accident, processes, as current pulse is bigger and ratio of appearance also is increased irrespective of amount of load.

Arc Detection and Interruption Algorithm Design for Fire Protection (화재 방지를 위한 아크전류 검출 제어기 설계)

  • Ban, Gi-Jong;Won, Young-Jin;Lim, Seung-Ha
    • Journal of the Institute of Electronics Engineers of Korea TE
    • /
    • v.42 no.3
    • /
    • pp.19-24
    • /
    • 2005
  • Arc Fault Current is an electric discharge which is occurred in two opposite electrode. In this paper, arc current control algorithm is designed for the interruption of arc fault current which is occurred in the local electric network. This arc is one of the main causes of electric fire. Arc fault in electrical network has the characteristics of low current, high impedance and high frequency. Conventional arc current controller does not have the arc current interrupt function. Hence, Controller of arc current is designed for the interruption of arc fault current which has the modified arc characteristics.

A Novel Non-contact Measurement Method for the Detection of Current Flowing Through Concealed Conductors

  • Yang, Fan;Liu, Kai;Zhu, Liwei;Hu, Jiayuan;Wang, Xiaoyu;Shen, Xiaoming;Luo, Hanwu;Ammad, Jadoon
    • Journal of Magnetics
    • /
    • v.22 no.1
    • /
    • pp.43-48
    • /
    • 2017
  • In order to detect the current flowing through concealed conductor, this paper proposes a new method based on derivative method. Firstly, this paper analyzes the main peak characteristic of the derivative function of magnetic field generated by a current-carrying conductor, and a relationship between the current flowing through the conductor and the main peak of the derivative function is obtained and applied to calculate the current. Then, the method is applied to detect the conductor current flowing through grounding grids of substations. Finally, the numerical experimental and field experiment verified the feasibility and accuracy of the method, and the computing results show that the method can effectively measure the conductor current of grounding grids with low error, and the error is within 5 %.

Single Current Sensor Technique considering a Snubber Current and a Modified SVPWM Inverter for AC Motor Drives (스누버 전류를 고려한 개선된 SVPWM 인버터를 이용한 상전류센서없는 전동기 구동)

  • 주형길;신휘범;안희욱;윤명중
    • Proceedings of the KIPE Conference
    • /
    • 1999.07a
    • /
    • pp.399-402
    • /
    • 1999
  • The single sensor technique reconstructing phase currents from the dc-link current without phase current sensors in proposed. When the duration of active vector is too short for the snubber current to reduce, the dc-link current including the snubber current gives large detection error. The solution is presented by analyzing the snubber current and modifying the switching sequences. This scheme is simple, requires only one sampling a period and has good results for detecting the phase currents.

  • PDF

Spin Signals in Lateral Spin Valves with Double Nonmagnetic Bottom Electrodes

  • Lee, B.C.
    • Journal of Magnetics
    • /
    • v.13 no.3
    • /
    • pp.81-84
    • /
    • 2008
  • Spin injection and detection in lateral spin valves with double nonmagnetic bottom electrodes are investigated theoretically. Spin-polarized current injected from a magnetic electrode is split to two bottom electrodes, and nonlocal spin signals between the other magnetic electrode and the nonmagnetic electrodes are calculated from drift-diffusion equations. It is shown that the spin signal is approximately proportional to the associated current in the electrode.