• Title/Summary/Keyword: 주파수-디지털 변환기

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Real-Time Head Tracking using Adaptive Boosting in Surveillance (서베일런스에서 Adaptive Boosting을 이용한 실시간 헤드 트래킹)

  • Kang, Sung-Kwan;Lee, Jung-Hyun
    • Journal of Digital Convergence
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    • v.11 no.2
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    • pp.243-248
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    • 2013
  • This paper proposes an effective method using Adaptive Boosting to track a person's head in complex background. By only one way to feature extraction methods are not sufficient for modeling a person's head. Therefore, the method proposed in this paper, several feature extraction methods for the accuracy of the detection head running at the same time. Feature Extraction for the imaging of the head was extracted using sub-region and Haar wavelet transform. Sub-region represents the local characteristics of the head, Haar wavelet transform can indicate the frequency characteristics of face. Therefore, if we use them to extract the features of face, effective modeling is possible. In the proposed method to track down the man's head from the input video in real time, we ues the results after learning Harr-wavelet characteristics of the three types using AdaBoosting algorithm. Originally the AdaBoosting algorithm, there is a very long learning time, if learning data was changes, and then it is need to be performed learning again. In order to overcome this shortcoming, in this research propose efficient method using cascade AdaBoosting. This method reduces the learning time for the imaging of the head, and can respond effectively to changes in the learning data. The proposed method generated classifier with excellent performance using less learning time and learning data. In addition, this method accurately detect and track head of person from a variety of head data in real-time video images.

Design of CFL Linearisation Chip for the Mobile Radio Using Ultra-Narrowband Digital Modulation (디지털 초협대역 단말기용 CFL 선형화 칩 설계)

  • Chong Young-Jun;Kang Min-Soo;Yoo Sung-Jin;Chung Tae-Jin;Oh Seung-Hyeub
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.7 s.98
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    • pp.671-680
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    • 2005
  • The CFL linearisation chip which is one of key devices in ultra-narrowband mobile radio transmitter using CQPSK digital modulation method is designed and implemented with $0.35{\mu}m$ CMOS technology. The reduced size and low cost of transmitter are available by the use of direct-conversion and CFL ASIC chip, which improve the power effi챠ency and linearity of transmitting path. In addition, low power operation is possible through CMOS technology The performance test results of transmitter show -25 dBc improvement of IMD level at the 3 kHz frequency offset and then satisfy FCC 47 CFR 90.210 E emission mask in the operation of CFL ASIC chip. At that time, the transmitting power is about PEP(Peak-to-Envelope Power) 5 W. The main parameters to improve the transmitting characteristic and to compensate the distortion in feed back loop such as DC-offset, loop gain and phase value are interfaced with notebook PC to be controlled with S/W.

Design of a Readout Circuit of Pulse Rate and Pulse Waveform for a U-Health System Using a Dual-Mode ADC (이중 모드 ADC를 이용한 U-Health 시스템용 맥박수와 맥박파형 검출 회로 설계)

  • Shin, Young-San;Wee, Jae-Kyung;Song, Inchae
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.9
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    • pp.68-73
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    • 2013
  • In this paper, we proposed a readout circuit of pulse waveform and rate for a U-health system to monitor health condition. For long-time operation without replacing or charging a battery, either pulse waveform or pulse rate is selected as the output data of the proposed readout circuit according to health condition of a user. The proposed readout circuit consists of a simple digital logic discriminator and a dual-mode ADC which operates in the ADC mode or in the count mode. Firstly, the readout circuit counts pulse rate for 4 seconds in the count mode using the dual-mode ADC. Health condition is examined after the counted pulse rate is accumulated for 1 minute in the discriminator. If the pulse rate is out of the preset normal range, the dual-mode ADC operates in the ADC mode where pulse waveform is converted into 10-bit digital data with the sampling frequency of 1 kHz. These data are stored in a buffer and transmitted by 620 kbps to an external monitor through a RF transmitter. The data transmission period of the RF transmitter depends on the operation mode. It is generally 1 minute in the normal situation or 1 ms in the emergency situation. The proposed readout circuit was designed with $0.11{\mu}m$ process technology. The chip area is $460{\times}800{\mu}m^2$. According to measurement, the power consumption is $161.8{\mu}W$ in the count mode and $507.3{\mu}W$ in the ADC mode with the operating voltage of 1 V.

HVS Model-based Watermarking Robust to Lossy Compression, Cropping, and Scaling (유손실 압축, 잘라내기 및 신축에 대해 견고한 HVS 모델 기반 워터마킹)

  • Hong, Su-Gi;Jo, Sang-Hyeon;Choe, Heung-Mun
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.38 no.5
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    • pp.548-555
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    • 2001
  • In this paper, we proposed a HVS(human visual system) model-based digital image watermarking which is not only invariant to rotation and translation but also more robust to lossy compression, cropping, and scaling as compared to the conventional method. Fourier transform and log-polar mapping is used to make the proposed algorithm invariant to rotation and translation, and in addition, watermark energy is embedded maximally based on spatial frequency sensitivity of HVS without the deterioration of the invisibility. As a result, the robustness of watermarking is improved both in general image processing operations such as cropping, low pass filtering, and lossy compression and in geometrical transforms such as rotation, translation, and scaling. And, by disjoint embedding of the watermark and the template without intersection, the deterioration of invisibility and robustness is prevented. Experimental results show that proposed watermarking is about 30~75 [%] more robust af compared to the conventional methods.

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A Study on the Characteristics of the Parameters for the Statistical Analysis of Vibration Signal by Using Bearing Wear Test (베어링 마모시험을 이용한 진동신호의 통계적 파라미터 특성연구)

  • Jun, Oh-Sung;Hwang, Cheol-Ho;Yoon, Byung-Ok;Eun, Hee-Joon
    • The Journal of the Acoustical Society of Korea
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    • v.8 no.1
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    • pp.5-12
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    • 1989
  • This paper is concerned with the characteristics on the statistical parameters of vibration signal from bearing with changing its operating conditions as well as the spreading of faults. The rms, Kurtosis, crest factor, probability of exceedance and probability density function have been chose as the statistical parameters. To characterize of each, vibration signals have been recorded from four ball tester at different loads, operation speeds and time. The values of the statistical parameters for each frequency band have been calculated after A/D conversion and digital filtering of the recorded signals. It has been found that unlike rms values the statistical parameters such as Kurtosis etc. are almost unchanging with the change of the operating conditions such as load and speed. This suggests that the statistical parameters may be used for determining the development of faults independent of the operating conditions. In fact, the statistical parameters deviate considerably from their respective normal values when the faults developed under load conditions in the samples, conforming the suggestion.

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A Study on Reconstruction Performance of Phase-only Holograms with Varying Propagation Distance (전파 거리에 따른 위상 홀로그램 복원성능 분석 및 BL-ASM 개선 방안 연구)

  • Jun Yeong Cha;Hyun Min Ban;Seung Mi Choi;Jin Woong Kim;Hui Yong Kim
    • Journal of Broadcast Engineering
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    • v.28 no.1
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    • pp.3-20
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    • 2023
  • A computer-generated hologram (CGH) is a digitally calculated and recorded hologram in which the amplitude and phase information of an image is transmitted in free space. The CGH is in the form of a complex hologram, but it is converted into a phase-only hologram to display through a phase-only spatial light modulator (SLM). In this paper, in the process of including the amplitude information of an object in the phase information, when a technique that includes subsampling such as DPAC is used, we showed experimentally that the bandwidth of the phase-only hologram increases, and as a result, aliasing that was not present in the complex hologram can occur. In addition, it was experimentally shown that it is possible to generate a high-quality phase-only hologram by restricting the spatial frequency range even at a distance where the numerical reconstruction performance is degraded by aliasing.

Development of a Multichannel Eddy Current Testing Instrument(II) (다중채널 와전류탐상검사 장치 개발(II))

  • Lee, Hee-Jong;Nam, Min-Woo;Cho, Chan-Hee;Yoo, Hyun-Joo;Kim, In-Chel
    • Journal of the Korean Society for Nondestructive Testing
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    • v.31 no.5
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    • pp.552-559
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    • 2011
  • Recently, the eddy current testing(ECT), alternating current field testing, magnetic flux leakage testing and remote field testing have been used as a nondestructive evaluation method based on the electromagnetic induction phenomenon. The eddy current testing is now widely accepted as a NDE method for the heat exchanger tube in the electric power industry, chemical, shipbuilding, and military. The ECT system mainly consists of the synthesizer module, analog module, analog-to-digital converter, power supplier, and data acquisition and analysis program. In the previous study, the synthesizer module and the analog module which is essential to the ECT system were primarily developed, and in this study the data acquisition and analysis program were developed. The operation system for this program is based on the Windows 7, and optimized for the Korean users, and the specific feature of this program using setup wizard enables inspector to make a setup easily for acquisition and analysis of ECT data. In this paper, the configuration and functions of eddy current data acquisition and analysis program will be introduced.

Study on Analysis of Queen Bee Sound Patterns (여왕벌 사운드 패턴 분석에 대한 연구)

  • Kim Joon Ho;Han Wook
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.5
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    • pp.867-874
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    • 2023
  • Recently, many problems are occurring in the bee ecosystem due to rapid climate change. The decline in the bee population and changes in the flowering period are having a huge impact on the harvest of bee-keepers. Since it is impossible to continuously observe the beehives in the hive with the naked eye, most people rely on knowledge based on experience about the state of the hive.Therefore, interest is focused on smart beekeeping incorporating IoT technology. In particular, with regard to swarming, which is one of the most important parts of beekeeping, we know empirically that the swarming time can be determined by the sound of the queen bee, but there is no way to systematically analyze this with data.You may think that it can be done by simply recording the sound of the queen bee and analyzing it, but it does not solve various problems such as various noise issues around the hive and the inability to continuously record.In this study, we developed a system that records queen bee sounds in a real-time cloud system and analyzes sound patterns.After receiving real-time analog sound from the hive through multiple channels and converting it to digital, a sound pattern that was continuously output in the queen bee sound frequency band was discovered. By accessing the cloud system, you can monitor sounds around the hive, temperature/humidity inside the hive, weight, and internal movement data.The system developed in this study made it possible to analyze the sound patterns of the queen bee and learn about the situation inside the hive. Through this, it will be possible to predict the swarming period of bees or provide information to control the swarming period.