• Journal of IKEEE
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• v.8 no.1 s.14
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• pp.128-135
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• 2004

This paper proposes a phase measurement algorithm which is based on the recursive implementation of sliding-DFT. The algorithm is designed to have a robust behavior against the erroneous factors of frequency drift, additive noise, and twiddle factor approximation. The size of phase error caused by the finite wordlength implementation of DFT twiddle factors is shown significantly lower than that of magnitude error. The drastic reduction of the phase error is achieved by the exploitation of the quadruplet symmetry characteristics of the approximated twiddle factors in the complex plane. Four channel power-line phase measurement system is also designed and implemented based on the time-multiplexed sharing architecture of the proposed algorithm. The operation of the developed system is also verified by the experiment performed under the test environment implemented with the multi-channel function generator and the on-line interfaced host processor system. The proposed algorithm's features of phase measurement accuracy and its robustness against the finite wordlength effects can provide a significant impact especially for the ASIC or microprocessor based embedded system applications where the enhanced processing speed and implementation simplicity are crucial design considerations.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.163-174
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• 2002

Speeding has been reported as one of the major causes for fatal traffic accidents in Korea. The resolution against this dangerous speeding comes to make the automated speed enforcement system an enforcement tool. The speed detection device, which measures speeds of each incoming vehicles using double loop sensors, requires high accuracy. The object of this study is to develop an accurate speed measurement algorithm using double loop detectors. Some important findings are summarized as follows: 1) It was found that speed measurement errors are caused by scanning rate, distance of two loops, irregular vehicle trajectories, multiple vehicles in detection zone. 2) A proposed algorithm using two signal set proved to reduce variance as well as mean of speed measurement. 3) A proposed filtering algorithm was effective to filter irregular driving vehicles and multiple vehicles in detection zone. A comprehensive field test of developed algorithm resulted in significant improvement of speed measurement accuracy.

• Journal of Sasang Constitutional Medicine
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• v.22 no.4
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• pp.20-29
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• 2010

1. Objectives Our goal is to observe the feasibility of constitution discrimination from computing quantitative roughness index from dynamic friction coefficients and their gradients with the measurement device of skin friction with 3-Axis load cell sensor. 2. Methods In the traditional Korean medicine, skin diagnosis is one of the examination methods to discriminate Sasang constitution since it was known that Tae-eumin has rough skin, and Soyangin has smooth one. It is based on the skin roughness on the back of one's hand for the discrimination. The measurement device of skin friction with 3-axis load cell sensor has been developed in order to provide quantitative skin roughness through dynamic friction coefficients. The effective interval of the coefficients is obtained from the automatic sampling algorithm to use their curvature and slope. Then, Fisher's discriminant function of them makes the discrimination. 3. Results The success rate of extracting the effective interval was about 90% and the discriminant accuracy between Tae-eumin and Soyangin was 70% and 68% for men and women, respectively. The entire methods showed the possibility to distinguish between Tae-eumin and Soyangin by using stochastic properties of roughness index, which can make the entire system to include the measurement, the computation of the roughness index and the discrimination of constitution automatical. 4. Conclusions The measurement device, the automatic sampling algorithm of dynamic friction coefficients and the constitution discrimination algorithm were developed, respectively, and their combination can become the serial and automatic procedure for quantitative and objective skin diagnosis, which mimics the movement of the Oriental medical doctors' skin diagnosis. It can be applied to healthcare as well as the diagnosis of constitution in a u-Health system soon.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.2
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• pp.431-438
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• 2017

In this paper, the abdomen ECG(AECG) is employed to measure the mother's ECG instead of the conventioanl thoracic ECG measurement. The fetus ECG signal can be extracted from the AECG using an algorithm that utilizes the mobile fetal ECG measurement platform, which is based on the BLE (Bluetooth Low Energy). The algorithm has been implemented by using a replacement processor processed directly from the platform BLE instead of the large statistical data processing required in the ICA(Independent component analysis). The proposed algorithm can be implemented on a mobile BLE wireless ECG system hardware platform to process the maternal ECG. Wireless technology can realize a compact, low-power radio system for short distance communication and the IOT(Intenet of Things) enables the transmission of real-time ECG data. It was also implemented in the form of a compact module in order for mothers to be able to download and store the collected ECG data without having to interrupt or move the logger, and later link the module to a computer for downloading and analyzing the data. A mobile ECG measurement prototype is manufactured and tested to measure the FECG for pregnant women. The experimental results verify a real-time FECG extraction capability for the proposed system. In this paper, we propose an ECG measurement system that shows approximately 91.65% similarity to the MIT database and the conventional algorithm and SNR performance about 10% better.

• Journal of Korea Multimedia Society
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• v.25 no.2
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• pp.297-310
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• 2022

Road facilities such as CCTV poles have potential risk of collision accidents with a car. A collision detection algorithm installed in the facility allows the collision accident to be known remotely. Most collision detection algorithms are operated by simply focusing on whether a collision have occurred, because these methods are used to measure only acceleration data from a 3-axis sensor to detect collision. However, it is difficult to detect other detailed information such as malfunction of the sensor, collision direction and collision strength, because it is not known without witness the accident. Therefore, we proposed enhanced detection algorithm to get the collision direction, and the collision strength from the tilt of the facility after accident using a 9-axis sensor in this paper. In order to confirm the performance of the algorithm, an accuracy evaluation experiment was conducted according to the data measurement cycle and the invocation cycle to an detection algorithm. As a result, the proposed enhanced algorithm confirmed 100% accuracy for 50 weak collisions and 50 strong collisions at the 9-axis data measurement cycle of 10ms and the invocation cycle of 1,000ms. In conclusion, the algorithm proposed is expected to provide more reliable and detailed information than existing algorithm.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.2
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• pp.151-159
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• 2002

The method of accumulating a sequence of focused images is usually used for reconstruction of 3D object\\`s shape. To acquire a focused image, the conventional methods must calculate the focus measures of all pixels resulting in a long measurement time. This paper proposes a new method of reducing the computation time spent for deciding the focused pixels in the input image, which predicts the area in the image to calculate the focus measure based on a priori information on the object to be measured. The proposed algorithm estimates the area to consider in the next measurement based on the focused area in the present measurement. As the focus measure, Laplacian measure was used in this paper and the experiments have shown that the preposed algorithm may significantly reduce the calculation time. Although, as implied, this algorithm can be applied to only simple objects at this stage, advanced representation schemes will eliminate the restrictions on application domain.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3428-3434
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• 2010

In this paper, we proposed and implemented a quality measurement algorithm for IS-95 reverse-link signal. To measure the quality of the received signal, equalization, carrier frequency/phase offset estimation, and timing synchronization are essential. And, all signal processing are carried out with baseband signal. The equalizer works with 4-oversampled samples to remove ICI(InterChip Interference). The frequency/phase offset estimator is followed by timing synchronizer since it can work without aid of data and timing information. As the number of interpolation in timing synchronization increases, the measurement accuracy improves, but computation load increases simultaneously. Therefore, one need to choose adequately the number of interpolation regarding to the platform performance to be used for the proposed algorithm.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.2
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• pp.113-119
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• 2011

A frequency in electrical power system changes by the load fluctuation in utility grid, has an influence on a connected generator, and ultimately brings a big trouble in the power system. Therefore, a quick measurement of system frequency and governor control of power system is a very important factor in the reliability and the economic feasibility. Electromagnetic frequency relays in the past had the large power consumption and the difficulty of accurate measurement. After Researched and developed digital relays are very affected by the noise and the distortion, and the recently developed Microprocessor relays have problems of expensive device and time when measuring the frequency at 50[ms]. In this study, An improve algorithm that measures the power system frequency quickly and accurately is suggested, simulated by using Matlab and programmed using C code through DSP6713 KIT. This algorithm is tested to the arbitrary voltage waveform input. The results show that the suggested algorithm is effective in the accurate and quick frequency measurements.

• Geomechanics and Engineering
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• v.22 no.1
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• pp.81-95
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• 2020

Measurement of the unconfined compressive strength (UCS) of the rock is critical to assess the quality of the rock mass ahead of a tunnel face. In this study, extensive field studies have been conducted along 3,885 m of the new Nagasaki tunnel in Japan. To predict UCS, a hybrid model of artificial neural network (ANN) based on genetic algorithm (GA) optimization was developed. A total of 1350 datasets, including six parameters of the Measurement-While- Drilling data and the UCS were considered as input and output parameters respectively. The multiple linear regression (MLR) and the ANN were employed to develop contrast models. The results reveal that the developed GA-ANN hybrid model can predict UCS with higher performance than the ANN and MLR models. This study is of great significance for accurately and effectively evaluating the quality of rock masses in tunnel engineering.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.72-74
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• 2000

This paper presents the linear model of the measurement system with Phasor Measurement Units (PMU's) and the parallel processing technique to determinate state vectors of a power system. The conventional model of the PMU measurement system is in a dilemma that it is not applicable to optimal PMU placements and it needs more PMU to apply this model. In order to improve this defect, in this paper, the extended linear model which adaptable to optimal PMU placements considering the feature of zero injection bus is proposed. Because the proposed model is expressed as over-determined measurement equation, the efficient algorithm is needed. This paper proposed the partitioning scheme and the process algorithm for parallel determinating state vectors of a power system efficiently. The performance of the proposed linear model and the parallel processing algorithm is evaluated with IEEE sample systems.