• 한국항행학회논문지
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• 제16권6호
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• pp.997-1004
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• 2012

본 논문에서는 CDMA2000 1x 단말기 신호의 품질 측정을 위한 알고리즘을 제안하고 구현하였다. 제안된 알고리즘은 PC 기반 플랫폼에서 소프트웨어로 구현이 가능하도록 하였으며, 4배 오버샘플링된 입력 신호에 대하여 등화, PN 부호 동기 및 추적, 주파수 및 위상 오프셋 보상을 수행하여 수신 신호가 추출되고, 추출된 신호로부터 역확산, 복조를 통해 측정에 사용될 기준 신호를 재생성한다. 이 재생성된 신호와 추출된 신호를 이용하여 단말기의 신호 품질을 측정한다.

• Journal of Positioning, Navigation, and Timing
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• 제10권4호
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• pp.341-351
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• 2021

In this paper, a GNSS error generation simulator for Signal Quality Monitoring (SQM) is implemented by using Matlab based on mathematical models derived from the effect of GNSS signal and measurement errors. The GNSS signal measurement errors of interest in this paper include three cases such as Evil Wave Form (EWF), Multipath (MP) and Radio Frequency Interference (RFI). In order to verify the validity of the generated measurement errors, a simple form of metrics for detecting and monitoring GNSS errors is included in the simulator. The GNSS errors generated by the simulator are added to the GNSS measurement data from commercial GNSS receiver in real time, and then, the SQM is tested for various scenarios of each case configured by scenario setting of the user.

• 한국산학기술학회논문지
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• 제11권9호
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• pp.3428-3434
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• 2010

논문에서는 IS-95 역방향링크 신호의 품질 측정을 위한 알고리즘을 제안하고 구현하였다. 수신 신호의 품질을 측정하기 위해서는 등화, 반송파 주파수 및 위상 오프셋 추정, 타이밍 동기가 반드시 필요하며, 모든 신호처리는 기저대역에서 수행된다. 등화기는 칩간 간섭(InterChip Interference)을 제거하기 위해, 4배 오버샘플링된 샘플에 대해서 동작하도록 설계되었다. 반송파 주파수 및 위상 오프셋 추정은 데이터 및 타이밍 정보 없이도 가능하도록 하였기 때문에, 타이밍 동기 이전에 수행된다. 타이밍 동기 시에 사용되는 보간 수(Interpolation Number)에 따라 측정의 정확도가 증가하지만, 계산량도 증가하게 된다. 따라서, 제안된 알고리즘이 구현될 플랫폼 성능에 따라 보간 수를 적절히 선택해야한다.

• 대한산업공학회지
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• 제30권2호
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• pp.84-92
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• 2004

A process control procedure is proposed when 100% inspection is performed in a process with excellent capability. Only the incomplete measurement data is assumed to be available, i.e. the specific measurement value of the quality characteristic is not available for each item but it can be determined to be smaller or larger than any prescribed value. In the suggested model, a signal limit is introduced to determine whether the process under study is in control or not. If the quality characteristic of an incoming item exceeds the upper signal or the lower signal limit, the process is determined to be stopped or not by comparing the number of consecutively accepted items with a predetermined threshold number. The procedure is designed based on the type I and II errors. The performance of the model is evaluated by the expected number of items produced under the in-control and out-of-control states until the process is stopped.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권9호
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• pp.3559-3571
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• 2015

This paper addresses the problem of signal acquisition with a sparse representation in a given orthonormal basis using fewer noisy measurements. The authors formulate the problem statement for randomly measuring with strong signal noise. The impact of white Gaussian signals noise on the recovery performance is analyzed to provide a theoretical basis for the reasonable design of the measurement matrix. With the idea that the measurement matrix can be adapted for noise suppression in the adaptive CS system, an adapted selective compressive sensing (ASCS) scheme is proposed whose measurement matrix can be updated according to the noise information fed back by the processing center. In terms of objective recovery quality, failure rate and mean-square error (MSE), a comparison is made with some nonadaptive methods and existing CS measurement approaches. Extensive numerical experiments show that the proposed scheme has better noise suppression performance and improves the support recovery of sparse signal. The proposed scheme should have a great potential and bright prospect of broadband signals such as biological signal measurement and radar signal detection.

• 정보저장시스템학회논문집
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• 제1권1호
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• pp.53-57
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• 2005

In order to measure signal quality of optical disc such as CD or DVD, jitter is used traditionally. The signal attained from a disc by optical pick-up is processed by analog circuits. And then, binary signal can be obtained by using proper silcer. After the signal is changed into binary format, jitter is calculated as a time difference between the binary signal and the reference time. Jitter is used to express the signal quality. In this paper, a new method that is able to offer more precise measurement of the signal quality fur high density optical disc than the jitter is proposed. We named it LPSNR (Level Peak Signal to Noise Ratio). The relationship between bER (bit error rate) and LPSNR is shown in the paper.

• 한국정보통신학회논문지
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• 제20권7호
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• pp.1283-1289
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• 2016

전력은 현대 사회를 구성하는데 있어 필수적인 자원이다. 최근, 전력에 대한 수요가 급격하게 증가하였으며 전력 수요 증가는 전력 품질의 저하를 야기하였다. 현대 사회에서 전력 품질은 일반 가정과 산업 전반에 걸쳐 큰 문제를 일으킬 수 있는 중요한 요소가 되었다. 전력 품질 문제를 예방하기 위해서는 전력 품질에 대한 계측과 초기 대응이 중요하다. 본 논문에서는 실시간으로 전력 품질을 계측하고 고조파를 분석하여 모니터링 할 수 있는 시스템 제안한다. 마이크로칩의 dsPIC33FJ256GP710A칩을 이용한 DM240001보드를 이용하여 최대 3상 3선에 해당하는 배선 방식의 전력 품질을 계측하는 시스템을 설계하였고, 계측 알고리즘의 최적화로 전력 품질의 순간적인 변화를 측정할 수 있도록 하였다. 또한, 최대 31차에 해당하는 고조파들에 대하여 전압과 전류의 왜율과 수요 전류 왜율에 대해서도 측정 가능하도록 설계하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1717-1720
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• 2002

Objective quality measurement schemes that in- corporate properties of the human auditory system. The basilar membrane(BM) acts as a spectrum analyzer, spatially decomposing the signal into frequency components. Each filterbank is an implementation of the ERB, gam-machirp function. This filterbank is level-dependent asymmetric compensation filters. And for the validation of the auditory model, we calculate the CPD. Quality measurement is obtained from the result.

• 한국연소학회지
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• 제1권1호
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• pp.75-82
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• 1996

Laser induced incandescence, LII, recently developed technique for measuring soot concentration in flames, can overcome most of limitations of conventional laser extinction measurement. In this study, experiments were performed to investigate the effect of laser intensity, detection wavelength, and also laser beam quality on both LII signal at a particular position and peak-to-centerline LII signal ratio. The results of LII signal with increasing laser intensity shows its near-independence of laser intensity once threshold level of laser intensity has been reached. However, this near-independence depends on laser beam quality and the incident optical setup. The peak-to-centerline LII signal ratio slowly but continuously increases with laser power. This fact is due to the dependence of LII signal on particle mean diameter. LII signal is attenuated during it passes through the flame containing soot particles. The attenuation rate is inversely proportional to detection wavelength. In this study, LII signal at 680 nm band is 10% greater than the signal at 400 nm band.

• 한국항공운항학회지
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• 제18권1호
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• pp.11-18
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• 2010

GNSS(Global Navigation Satellite System) Ground Station performs GNSS signal acquisition and processing. This system generates error correction information and distributes them to GNSS users. GNSS Ground Station consists of sensor station which contains receiver and meteorological sensor, monitoring and control subsystem which monitors and controls sensor station, control center which generates error correction information, and uplink station which transmits correction information to navigation satellites. Monitoring and control subsystem acquires and processes navigation data from sensor station. The processed data is transmitted to GNSS control center. Monitoring and control subsystem consists of data acquisition module, data formatting and archiving module, data error correction module, navigation determination module, independent quality monitoring module, and system maintenance and management module. The independent quality monitoring module inspects navigation signal, data, and measurement. This paper introduces independent quality monitoring and performs the analysis using measurement data.