• Title/Summary/Keyword: car noise

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Driver's Status Recognition Using Multiple Wearable Sensors (다중 웨어러블 센서를 활용한 운전자 상태 인식)

  • Shin, Euiseob;Kim, Myong-Guk;Lee, Changook;Kang, Hang-Bong
    • KIPS Transactions on Computer and Communication Systems
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    • v.6 no.6
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    • pp.271-280
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    • 2017
  • In this paper, we propose a new safety system composed of wearable devices, driver's seat belt, and integrating controllers. The wearable device and driver's seat belt capture driver's biological information, while the integrating controller analyzes captured signal to alarm the driver or directly control the car appropriately according to the status of the driver. Previous studies regarding driver's safety from driver's seat, steering wheel, or facial camera to capture driver's physiological signal and facial information had difficulties in gathering accurate and continuous signals because the sensors required the upright posture of the driver. Utilizing wearable sensors, however, our proposed system can obtain continuous and highly accurate signals compared to the previous researches. Our advanced wearable apparatus features a sensor that measures the heart rate, skin conductivity, and skin temperature and applies filters to eliminate the noise generated by the automobile. Moreover, the acceleration sensor and the gyro sensor in our wearable device enable the reduction of the measurement errors. Based on the collected bio-signals, the criteria for identifying the driver's condition were presented. The accredited certification body has verified that the devices has the accuracy of the level of medical care. The laboratory test and the real automobile test demonstrate that our proposed system is good for the measurement of the driver's condition.

Failure Examples Study Including with timing belt, Constant Velocity Boot and Weather strip on a Car (자동차의 타이밍벨트, 등속조인트 부트, 웨더 스트립에 관련된 고장사례 고찰)

  • Lee, Il Kwon;Lee, Jong Ho;Hwang, Han Sub;Yim, Ha Young;You, Chang Bae;Kim, Young Kyu;Kim, Choo Ha
    • Journal of the Korean Institute of Gas
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    • v.19 no.1
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    • pp.6-11
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    • 2015
  • This paper is to study the examples for rubber damage and weaken reliability of timing belt, constant velocity joint boot and weather strip in vehicle. The first example, when the service man replaced the new timing-belt of rubber material, he assembled the belt that was weaken it's contact surface because of material transform. He knew the abnormally tearing failure by friction action between belt and sprocket. The second example, it certified the fact that the grease is leaked out boot protecting of constant velocity joint by split of rubber surface because of durability badness. The third example, the weather stripe took the minutely tearing because of damage produced the material transform by crack of chemistry change. It certified the production phenomenon of a tiny noise by coming with outside air because of overlapped the rubber of weather stripe when driving after closing the door. Therefore, the driver must always manage the rubber system part of vehicle.

Design of 77 GHz Automotive Radar System (77 GHz 차량용 레이더 시스템 설계)

  • Nam, Hyeong-Ki;Kang, Hyun-Sang;Song, Ui-Jong;Cui, Chenglin;Kim, Seong-Kyun;Nam, Sang-Wook;Kim, Byung-Sung
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.24 no.9
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    • pp.936-943
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    • 2013
  • This work presents the design and measured results of the single channel automotive radar system for 76.5~77 GHz long range FMCW radar applications. The transmitter uses a commercial GaAs monolithic microwave integrated circuit(MMIC) and the receiver uses the down converter designed using 65 nm CMOS process. The output power of the transmitter is 10 dBm. The down converter chip can operate at low LO power as -8 dBm which is easily supplied from the transmitter output using a coupled line coupler. All MMICs are mounted on an aluminum jig which embeds the WR-10 waveguide. A microstrip to waveguide transition is designed to feed the embedded waveguide and finally high gain horn antennas. The overall size of the fabricated radar system is $80mm{\times}61mm{\times}21mm$. The radar system achieved an output power of 10 dBm, phase noise of -94 dBc/Hz at 1 MHz offset and a conversion gain of 12 dB.

Analysis of the Ecological Efficiency of Chinese Provincial Based on the Three-stage DEA Model (3단계 DEA모델을 이용한 중국의 에코 효율성 측정에 관한 연구)

  • Na, Sang Gyun;Niu, Jian Guang
    • Management & Information Systems Review
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    • v.36 no.2
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    • pp.307-327
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    • 2017
  • Ecological efficiency is an important index measuring and reflecting the sustainable development level of economy, resources and environment in a region. This paper makes an empirical study on the ecological efficiency of 31 provinces in China in 2014 with the three-stage DEA model. The results show that the three indexes, the total investment in environmental governance (Unit: hundred million Yuan), the second industry proportion(%), and per capita automobile ownership (car/ten thousand people) functioning as the external environmental variables have significantly impacted the regional ecological efficiency. Excluding the impact of the external environment and statistical noise, the technical efficiency of regional ecological efficiency has increased from 0.526 to 0.639, and the pure technical efficiency has increased from 0.650 to 0.858, with the scale efficiency decreased from 0.833 to 0.740, accurately reflecting the regional ecological efficiency level. 31 Chinese provinces are classified into four different types according to the pure technical efficiency and scale efficiency. Every region shall, according to the characteristics of its efficiency, emphasize differently on improving the management level or expanding the scale of production so as to improve the ecological efficiency.

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A Study on Lip-reading Enhancement Using Time-domain Filter (시간영역 필터를 이용한 립리딩 성능향상에 관한 연구)

  • 신도성;김진영;최승호
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.5
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    • pp.375-382
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    • 2003
  • Lip-reading technique based on bimodal is to enhance speech recognition rate in noisy environment. It is most important to detect the correct lip-image. But it is hard to estimate stable performance in dynamic environment, because of many factors to deteriorate Lip-reading's performance. There are illumination change, speaker's pronunciation habit, versatility of lips shape and rotation or size change of lips etc. In this paper, we propose the IIR filtering in time-domain for the stable performance. It is very proper to remove the noise of speech, to enhance performance of recognition by digital filtering in time domain. While the lip-reading technique in whole lip image makes data massive, the Principal Component Analysis of pre-process allows to reduce the data quantify by detection of feature without loss of image information. For the observation performance of speech recognition using only image information, we made an experiment on recognition after choosing 22 words in available car service. We used Hidden Markov Model by speech recognition algorithm to compare this words' recognition performance. As a result, while the recognition rate of lip-reading using PCA is 64%, Time-domain filter applied to lip-reading enhances recognition rate of 72.4%.

Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2014 (설비공학 분야의 최근 연구 동향: 2014년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.7
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    • pp.380-394
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    • 2015
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

Improved Method of License Plate Detection and Recognition using Synthetic Number Plate (인조 번호판을 이용한 자동차 번호인식 성능 향상 기법)

  • Chang, Il-Sik;Park, Gooman
    • Journal of Broadcast Engineering
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    • v.26 no.4
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    • pp.453-462
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    • 2021
  • A lot of license plate data is required for car number recognition. License plate data needs to be balanced from past license plates to the latest license plates. However, it is difficult to obtain data from the actual past license plate to the latest ones. In order to solve this problem, a license plate recognition study through deep learning is being conducted by creating a synthetic license plates. Since the synthetic data have differences from real data, and various data augmentation techniques are used to solve these problems. Existing data augmentation simply used methods such as brightness, rotation, affine transformation, blur, and noise. In this paper, we apply a style transformation method that transforms synthetic data into real-world data styles with data augmentation methods. In addition, real license plate data are noisy when it is captured from a distance and under the dark environment. If we simply recognize characters with input data, chances of misrecognition are high. To improve character recognition, in this paper, we applied the DeblurGANv2 method as a quality improvement method for character recognition, increasing the accuracy of license plate recognition. The method of deep learning for license plate detection and license plate number recognition used YOLO-V5. To determine the performance of the synthetic license plate data, we construct a test set by collecting our own secured license plates. License plate detection without style conversion recorded 0.614 mAP. As a result of applying the style transformation, we confirm that the license plate detection performance was improved by recording 0.679mAP. In addition, the successul detection rate without image enhancement was 0.872, and the detection rate was 0.915 after image enhancement, confirming that the performance improved.