• Title/Summary/Keyword: power of discrimination

Search Result 287, Processing Time 0.025 seconds

Verification Test of High-activity SMEs Using Technology Appraisal Items (기술력 평가항목을 이용한 고활동성 중소기업 판별)

  • Lee, Jun-won
    • Journal of Technology Innovation
    • /
    • v.28 no.1
    • /
    • pp.31-52
    • /
    • 2020
  • This study was started to verify the preliminary(Ex-ante) discrimination power of the firm's high-activity using the 'Forward-looking' oriented technology appraisal model used in technology financing. The analytical firms are classified into the industry (manufacturing / non-manufacturing) and the age of company (initial / non-initial). High-activity SMEs are defined as those that achieve at least twice the average asset turnover ratio of the cluster. As a result of the discriminant model by applying C5.0 method, which is one of decision tree models, classification accuracy is more than 99% in all industries and the age of company, and it is confirmed that the discriminant power of the model is stable. As a result, the management expertise, capital involvement and funding capacity items were identified as a critical variable for the high-activity SMEs. In addition, the technology management capability and technology life cycle were also confirmed to be the items to determine high-activity SMEs in the manufacturing industry. Through this, it was possible to confirm some possibility of prior discrimination and policy utilization of high-activity SMEs by using technology appraisal items.

A Study on Frequency Coordination between the Same or Different Wireless Systems based upon Minimum Coupling Loss (최소결합손실 기반의 동종 또는 이종 무선시스템 간의 주파수 조정에 대한 연구)

  • Suh, Kyoung-Whoan
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.18 no.2
    • /
    • pp.63-72
    • /
    • 2018
  • Theoretical modelling and computational results for frequency coordination are presented based upon minimum coupling loss regarding the same or different wireless systems. Essential parameters involved in frequency coordination are discussed in view of system characteristics, propagation model, availability and protection ratio, frequency dependent rejection or adjacent channel interference ratio, discrimination angle, and its computational results are also evaluated. To illustrate frequency coordination procedure, received interference power between fixed wireless system of victim and mobile base station of interferer are analyzed in urban or sub-urban area and also compared with maximum allowable interference power as functions of discrimination angle and distance for assumed system parameters. The proposed method will play a practical role in technical analysis on co-existence or interoperability for the various wireless systems needed for frequency coordination.

Faults Current Discrimination of Power System Using Wavelet Transform (웨이블렛 변환을 이용한 전력시스템 고장전류의 판별)

  • Lee, Joon-Tark;Jeong, Jong-Won
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.21 no.3
    • /
    • pp.75-81
    • /
    • 2007
  • Recently the subject of "wavelet analysis" has be drawn by both mathematical and engineering application fields such as Signal Processing, Compression/Decomposition, Wavelet-Neural Network, Statistics and etc. Even though its similar to Fourier analysis, wavelet is a versatile tool with much mathematical content and great potential for applications. Especially, wavelet transform uses localizable various mother wavelet functions in time-frequency domain. Therefore, wavelet transform has good time-analysis ability for high frequency component, and has good frequency-analysis ability for low frequency component. Using the discriminative ability is more easy method than other conventional techniques. In this paper, Morlet wavelet transform was applied to discriminate the kind of line fault by acquired data from real power transformation network. The experimental result presented that Morlet wavelet transform is easier, and more useful method than the Fast Fourier Transform(FFT).

Fault Location Technique of 154 kV Substation using Neural Network (신경회로망을 이용한 154kV 변전소의 고장 위치 판별 기법)

  • Ahn, Jong-Bok;Kang, Tae-Won;Park, Chul-Won
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.67 no.9
    • /
    • pp.1146-1151
    • /
    • 2018
  • Recently, researches on the intelligence of electric power facilities have been trying to apply artificial intelligence techniques as computer platforms have improved. In particular, faults occurring in substation should be able to quickly identify possible faults and minimize power fault recovery time. This paper presents fault location technique for 154kV substation using neural network. We constructed a training matrix based on the operating conditions of the circuit breaker and IED to identify the fault location of each component of the target 154kV substation, such as line, bus, and transformer. After performing the training to identify the fault location by the neural network using Weka software, the performance of fault location discrimination of the designed neural network was confirmed.

Second Toe to Finger Transfer in Traumatic Amputated Index (외상성 수지 절단에서 인지 재건을 위한 제 2 족지이식)

  • Lee, Kwang-Suk;Hahn, Seung-Beom;Lee, Seoung-Joon;Park, Sung-Joon
    • Archives of Reconstructive Microsurgery
    • /
    • v.11 no.1
    • /
    • pp.41-46
    • /
    • 2002
  • Purpose : To assess the clinical results of second toe-to-finger transfer in traumatic amputated index finger. Materials and Methods : For the clinical evaluation, we have analyzed 12 patients with ROM of finger joints, pinch power, static two point discrimination, life functional assessment, and patient's satisfaction. Results : In genral ROM was $54.4^{\circ}$ at MP joint, $17^{\circ}$ at PIP joint and $6.7^{\circ}$ at DIP joint. Pinch power was good in 3 cases, fair in 7 cases, and poor in 2 cases. Daily life activity and patient's acceptance were satisfactory. Conclusion : Although transfered toe function may be poorer than normal finger, the hand was restored to a useful, sensate and versatile functional unit.

  • PDF

A Study on a Fault Location Algorithm Using Wavelet Transform in Combined Transmission Systems (혼합송전계통에서 웨이브렛 변환을 이용한 고장점 탐색 알고리즘에 관한 연구)

  • Jeong, Chae-Gyun;Lee, Jong-Beom;Yun, Yang-Ung
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.51 no.5
    • /
    • pp.247-254
    • /
    • 2002
  • This paper describes a fault location algorithm in real combined transmission systems with underground power cable. The algorithm to calculate the fault location was developed using DWT wavelet transform and travelling wave occurred at fault point. And the proposed algorithm is also used the transient signal of one end in stead of the signal information of two ends. On the other hand, in this papers, the method to discriminate fault point between overhead line and cable section is also Proposed. Variety simulations were carried out to verify the accuracy and effectiveness of the proposed algorithm using EMTP/ATFDraw and Matlab. Simulation results show that the proposed method has the excellent ability for discrimination of fault section and fault location in combined transmission systems with power cables.

Insulation Aging Diagnostics of Submarine Medium Voltage Power Cables (배전급 해저케이블의 절연열화진단)

  • Mo, Jong-Myung;Yi, Dong-Young;Song, Kwang-Yong
    • Proceedings of the KIEE Conference
    • /
    • 2001.11b
    • /
    • pp.149-152
    • /
    • 2001
  • In this work, we have conducted insulation aging assessment and maintenance for submarine medium voltage power cable systems to discriminate and maintain bad cables economically. We have found that aging status of submarine cable systems are very poor and in progress. We have found that insulation status were improved with the replacement of cable terminations. We have confirmed with the electrical and structural analysis of terminations, that the poor aging status of cables are mainly caused not by the cable insulations but by the aging of cable terminations. From the above results, we have also confirmed that the domestic diagnostic system is successful and convenient for the discrimination and maintenance of the damaged cables economically.

  • PDF

A Development of Software about Short-circuit Calculation and Protective-coordination (고장계산 및 보호협조 판정 소프트웨어 개발)

  • Park, S.C.;Choe, J.H.;Seo, J.M.
    • Proceedings of the KIEE Conference
    • /
    • 2002.07a
    • /
    • pp.159-162
    • /
    • 2002
  • A software, called touch-one, is developed about the determination of short-circuit values and protective co-ordination in power system. The used solution algorithm reviewed intensively, and the protective co-ordination determination technique presented by using the circuit-breaker's current-limitation characteristic. The protective coordination concerns the behaviour of two devices placed in series in an electrical network, with a short-circuit downstream circuit-breaker. It has two basic principles: First, discrimination which is an increasing requirement of low voltage electrical distribution systems. Second, which is less well known: cascading, which consists of installing a device, whose breaking capacity is less than the three-phase short-circuit current at its terminals and helped by main circuit-breaker. With this software, we can construct a electric-power system which is reliable and economic according to user's purpose.

  • PDF

A Daubechies Wavelet Transform Based Criterion Logic Scheme for Discrimination Between Inter-Turn Faults and Magnetizing Inrush in Transformer (도비시 웨이브렛 변환을 이용한 변압기의 여자돌입과 내부 권선고장 판별논리 기법)

  • Kwon, Myong-Hyun;Park, Chul-Won;Shin, Myong-Chul
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.50 no.5
    • /
    • pp.211-217
    • /
    • 2001
  • This paper proposes a new fault detection criterion logic that extracts the features of magnetizing inrush and internal faults by making use of Daubechies Wavelet Transform which analyzes distinct features. To prove the effectiveness of proposed method, the paper constructs power system model including power transformer by using EMTP, and collects data through simulation using various fault inception angle and magnetizing inrush. The conclusions implemented by the C program and the Wavemenu of MATLAB Toolbos are more effective and simpler to distinguish inter-turn faults from magnetizing inrush states.

  • PDF

PD Classification by Neural Networks in Specimen of XLPE Power Cable (XLPE 전력용 케이블 시편의 부분방전원 분류)

  • 박성희;이강원;강성화;임기조
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.17 no.8
    • /
    • pp.898-903
    • /
    • 2004
  • In this paper, neural networks is studied to apply as a PD source classification in XLPE power cable specimen. For treeing discharge sources in the specimen, three defected models are made. And these data making use of a computer-aided discharge analyser, statistical and other discharge parameters is calculated to discrimination between different models of discharge sources. And also these parameter is applied to classify PD sources by neural networks. Neural Networks has good recognition rate for three PD sources.