• Title/Summary/Keyword: Vehicle Noise

Search Result 1,642, Processing Time 0.024 seconds

Recognition of Car License Plates Using Difference Operator and ART2 Algorithm (차 연산과 ART2 알고리즘을 이용한 차량 번호판 통합 인식)

  • Kim, Kwang-Baek;Kim, Seong-Hoon;Woo, Young-Woon
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.13 no.11
    • /
    • pp.2277-2282
    • /
    • 2009
  • In this paper, we proposed a new recognition method can be used in application systems using morphological features, difference operators and ART2 algorithm. At first, edges are extracted from an acquired car image by a camera using difference operators and the image of extracted edges is binarized by a block binarization method. In order to extract license plate area, noise areas are eliminated by applying morphological features of new and existing types of license plate to the 8-directional edge tracking algorithm in the binarized image. After the extraction of license plate area, mean binarization and mini-max binarization methods are applied to the extracted license plate area in order to eliminated noises by morphological features of individual elements in the license plate area, and then each character is extracted and combined by Labeling algorithm. The extracted and combined characters(letter and number symbols) are recognized after the learning by ART2 algorithm. In order to evaluate the extraction and recognition performances of the proposed method, 200 vehicle license plate images (100 for green type and 100 for white type) are used for experiment, and the experimental results show the proposed method is effective.

A Study on an Impedance Matching Technique for Rail Power Line Communication (레일 전력선통신을 위한 임피던스 정합방안 연구)

  • Seo, Ill-Kwon;Ahn, Seung-Ho;Kim, Chul-Su
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.11
    • /
    • pp.202-207
    • /
    • 2016
  • An auxiliary real-time train communications system among drivers, train-traffic controllers and field workers is necessary to share hazard information (i.e. rockfall detection, track maintenance) in low visibility zones (long tunnels and steep curved track). To develop the appropriate communication system, this paper proposes a new way of power line communication using the rail track (Rail - PLC), which has little noise and distortion of attenuation. Therefore, it is important to measure the impedance of the rail and to apply an impedance matching technique to increase the transmission characteristic of the Rail - PLC. This study would evaluate the reflection and the transmission characteristics of the rail using a network analyzer and an impedance matching transformer. The suitable impedance matching ratio was 1:3.28 from the result of back-to-back testing. The results confirmed that the transformer can improve the performance of the transmission signal in Rail - PLC using an impedance matching technique.

Radius-Measuring Algorithm for Small Tubes Based on Machine Vision using Fuzzy Searching Method (퍼지탐색을 이용한 머신비전 기반의 소형 튜브 내경측정 알고리즘)

  • Naranbaatar, Erdenesuren;Lee, Sang-Jin;Kim, Hyoung-Seok;Bae, Yong-Hwan;Lee, Byung-Ryong
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.35 no.11
    • /
    • pp.1429-1436
    • /
    • 2011
  • In this paper, a new tube-radius-measuring algorithm has been proposed for effectively measuring the radii of small tubes under severe noise conditions that can also perform well when metal scraps that make it difficult to measure the radius correctly are inside the tube hole. In the algorithm, we adopt a fuzzy searching method that searches for the center of the inner circle by using fuzzy parameters for distance and orientation from the initial search point. The proposed algorithm has been implemented and tested on both synthetic and real-world tube images, and the performance is compared to existing circle-detection algorithms, such as the Hough transform and RANSAC methods, to prove the accuracy and effectiveness of the algorithm. From this comparison, it is concluded that the proposed algorithm has excellent performance in terms of measurement accuracy and computation time.

Object Detection in a Still FLIR Image using Intensity Ranking Feature (밝기순위 특징을 이용한 적외선 정지영상 내 물체검출기법)

  • Park Jae-Hee;Choi Hak-Hun;Kim Seong-Dae
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.42 no.2 s.302
    • /
    • pp.37-48
    • /
    • 2005
  • In this paper, a new object detection method for FLIR images is proposed. The proposed method consists of intensity ranking feature and a classification algerian using the feature. The intensity ranking feature is a representation of an image, from which intensity distribution is regularized. Each object candidate region is classified as object or non-object by the proposed classification algorithm which is based on the intensity ranking similarity between the candidate and object training images. Using the proposed algorithm pixel-wise detection results can be obtained without any additional candidate selection algorithm. In experimental results, it is shown that the proposed ranking feature is appropriate for object detection in a FLIR image and some vehicle detection results in the situation of existing noise, scale variation, and rotation of the objects are presented.

A Study on Link Analysis of Telemetry Rocket-borne Antenna (텔레메트리 로켓 탑재 안테나의 회선 분석에 관한 연구)

  • 김성완;황수설;이재득
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.15 no.3
    • /
    • pp.311-318
    • /
    • 2004
  • It is required to design the RF link with sufficiently stable signal margin to minimize bit errors and improve the quality of received data in the telemetry system modulated digitally like PCM/FM. In case of the vehicle flying at a high speed, the variation of the gain pattern between transmitting and receiving antenna and the fee space loss due to flight distance cause the fluctuation of link. In this paper, KSR(Korea Sounding Rocket)- III, the first domestic liquid rocket which was successfully launched in Nov. 2002 is introduced. The SNR(signal-to-noise ratio) variation of the telemetry signal which was measured at S-band ground station, the one which was simulated considering the flight trajectory, and the attitude variation such as roll, pitch and yaw are compared, analyzed, and agree very well. In addition, two virtual flying situations are simulated and evaluated-only one antenna is equipped in one case, and rocket is roll-free in the other.

Design of a Low-Power RF Transceiver for Small UAVs Using Switching Power (전원 스위칭을 이용한 저전력 소형무인기용 RF 송수신기 설계)

  • Kim, Hyo-Jong;Lee, Jong-Wook
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.28 no.10
    • /
    • pp.779-787
    • /
    • 2017
  • In this paper, we designed a RF transceiver for small unmanned aerial vehicle(UAV) using power switching method. To apply for the UAV, several characteristics such as size, weight, and power consumption are very important. To reduce power consumption, we propose a new power switching method. Using the proposed method, we fabricated the RF transceiver needed to establish the data link for a small UAV. The fabricated RF transceiver shows an output power of +25 dBm, a noise figure of 4.56 dB and a received signal strength of -100 dBm. By performing power measurement of proposed switching method, 25 % of power could be reduced. The size of the fabricated RF transceiver is $100{\times}60{\times}5.7mm^3$ and the weight is as small as 38 g.

Monitoring in-service performance of fibre-reinforced foamed urethane sleepers/bearers in railway urban turnout systems

  • Kaewunruen, Sakdirat
    • Structural Monitoring and Maintenance
    • /
    • v.1 no.1
    • /
    • pp.131-157
    • /
    • 2014
  • Special track systems used to divert a train to other directions or other tracks are generally called 'railway turnout'. A traditional turnout system consists of steel rails, switches, crossings, steel plates, fasteners, screw spikes, timber bearers, ballast and formation. The wheel rail contact over the crossing transfer zone has a dip-like shape and can often cause detrimental impact loads on the railway track and its components. The large impact also emits disturbing noises (either impact or ground-borne noise) to railway neighbors. In a brown-field railway track where an existing aged infrastructure requires renewal or maintenance, some physical constraints and construction complexities may dominate the choice of track forms or certain components. With the difficulty to seek for high-quality timbers with dimensional stability, a methodology to replace aged timber bearers in harsh dynamic environments is to adopt an alternative material that could mimic responses and characteristics of timber in both static and dynamic loading conditions. A critical review has suggested an application of an alternative material called fibre-reinforced foamed urethane (FFU). The full-scale capacity design makes use of its comparable engineering characteristics to timber, high-impact attenuation, high damping property, and a longer service life. A field trial to investigate in-situ behaviours of a turnout grillage system using an alternative material, 'fibre-reinforced foamed urethane (FFU)' bearers, has been carried out at a complex turnout junction under heavy mixed traffics at Hornsby, New South Wales, Australia. The turnout junction was renewed using the FFU bearers altogether with new special track components. Influences of the FFU bearers on track geometry (recorded by track inspection vehicle 'AK Car'), track settlement (based on survey data), track dynamics, and acoustic characteristics have been measured. Operational train pass-by measurements have been analysed to evaluate the effectiveness of the replacement methodology. Comparative studies show that the use of FFU bearers generates higher rail and sleeper accelerations but the damping capacity of the FFU help suppress vibration transferring onto other track components. The survey data analysis suggests a small vertical settlement and negligible lateral movement of the turnout system. The static and dynamic behaviours of FFU bearers appear to equate that of natural timber but its service life is superior.

Comparison and Analysis of Fuel Consumption by CODAD, CODLOD and CODLAD System for Combat Support Ship (군수지원함의 CODAD, CODLOD 및 CODLAD 추진체계에 따른 연료 소비량 비교 및 분석)

  • Kim, Min-wook;Oh, Jin-seok
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.21 no.5
    • /
    • pp.1049-1059
    • /
    • 2017
  • After patrol corvett Cheonan was hit and sank on duty, the Republic of Korea Navy has tried to install hybrid propulsion system on naval ship to reduce vibration and noise problems during navigation. The hybrid propulsion system has advantage that propulsion motor can be propelled in low speed operation of the vessel. This can be a better quietness than a mechanical propulsion system which consists of a conventional internal combustion engines. And more economical operation is possible by using a propulsion motor in a low speed operation where a fuel efficiency of the internal combustion engine is poor. In this paper, we set up virtual ship on the basis of a combat support ship in the Republic of Korea Navy, economically compared and analyzed fuel consumption between conventional and hybrid propulsion system. As a result, it was confirmed that the fuel efficiency of hybrid propulsion system which use electric motor had been relatively improved.

Acoustic Loads Reduction of Composite Plates for Nose Fairing Structure (노즈 페어링 구조용 복합재 평판의 음향 하중 저감 특성)

  • 박순홍;공철원;장영순;이영무
    • Composites Research
    • /
    • v.17 no.3
    • /
    • pp.15-22
    • /
    • 2004
  • Acoustic load generated by rocket propulsion system is one of major dynamic loads during lift-off phase so that it causes the structural failure and electronic malfunction of payloads. Acoustic loads can be greatly reduced by an appropriate acoustical design of nose faring structures. This paper deals with the acoustical design of the nose fairing structure for launch vehicle. It is well known that a honeycomb sandwich structure is a poor sound insulator because of its high specific stiffness. In this paper, the sound transmission characteristics of four kinds of honeycomb structures for noise fairing were investigated by means of numerical and experimental ways. In order to estimate transmission loss, infinite plate theory by Moore and Lyon and statistical energy analysis (SEA) method were used. The predicted results showed a good agreement with measured ones. These enabled us to determine a proper core material for nose fairing, which shows good sound insulation performance per weight.

Dynamic Characteristics of Plastic Materials for Automobile Cockpit Module (자동차 칵핏 모듈용 플라스틱 소재의 열화 동특성 평가)

  • Woo, Chang Su;Park, Hyun Sung;Jo, Jin Ho;Kim, Ji Hoon;Choi, Ju Ho;Kim, Yeoung Kuk
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.36 no.12
    • /
    • pp.1585-1590
    • /
    • 2012
  • Engineering plastics are used in instrument panels, interior trim, and other vehicle applications, and the thermomechanical behaviors of plastic materials are strongly influenced by many environmental factors such as temperature, sunlight, and rain. As the material properties change, the mechanical parts create unexpected noise. In this study, the dynamic mechanical property changes of plastics used in automobiles are measured to investigate the temperature effects. Viscoelastic properties such as the glass transition temperature and storage modulus and loss factor under temperature and frequency sweeps were measured. The data were compared with the original ones before aging to analyze the behavior changes. It was found that as the temperature increased, the storage modulus decreased and the loss factor increased slightly.