• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.444-447
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• 2004

A heart diagnosis system adopts hundreds of Superconducting Quantum Interface Device(SQUID) sensors for precision MCG(Magnetocardiogram) or MEG(Magnetoencephalogram) signal acquisitions. This system requires correct and real-time data acquisition from the sensors in a required sampling interval, i.e., 1 mili-second. This paper presents our hardware design and test results, to acquire data from 256 channel analog signal with 1-ksample/sec speed, using 12-bit 8-channel ADC devices, SPI interfaces, parallel interfaces, and 8-bit microprocessors. We chose to implement parallel data transfer between microprocessors as an effective way of achieving such data collection. Our result concludes that the data collection can be done in 250 ${\mu}sec$ time-interval.

• New & Renewable Energy
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• v.18 no.2
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• pp.18-25
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• 2022

In this study, we propose a wind power generation prediction system that applies machine learning and data mining to predict wind power generation. This system increases the utilization rate of new and renewable energy sources. For time-series data, the data set was established by measuring wind speed, wind generation, and environmental factors influencing the wind speed. The data set was pre-processed so that it could be applied appropriately to the model. The prediction system applied the CNN (Convolutional Neural Network) to the data mining process and then used the LSTM (Long Short-Term Memory) to learn and make predictions. The preciseness of the proposed system is verified by comparing the prediction data with the actual data, according to the presence or absence of data mining in the model of the prediction system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.1
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• pp.22-33
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• 2005

In this paper, an efficient signal interference control technique to improve the high convergence speed of LMS algorithms is introduced in the adaptive transversal filter of DS/SS. The convergence characteristics of the proposed algorithm, whose coefficients are multiply adapted in a symbol time period by recycling the received data, is analyzed to prove theoretically the improvement of high convergence speed. According as the step-size parameter ${\mu}$ is increased, the rate of convergence of the algorithm is controlled. Also, an increase in the stop-size parameter ${\mu}$ has the effect of reducing the variation in the experimentally computed learning curve. Increasing the eigenvalue spread has the effect of controlling which is downed the rate of convergence of the adaptive equalizer. Increasing the steady-state value of the average squared error, proposed algorithm also demonstrate the superiority of signal interference control to the filter algorithm increasing convergence speed by (B+1) times due to the data-recycling LMS technique.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.5A
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• pp.517-525
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• 2006

In this paper, we present a high-speed RFID data filtering engine designed to carry out filtering under the conditions of massive data and massive filters. We discovered that the high-speed RFID data filtering technique is very similar to the high-speed packet classification technique which is used in high-speed routers and firewall systems. Actually, our filtering engine is designed based on existing packet classification algorithms, Bit Parallelism and Aggregated Bit Vector(ABV). In addition, we also discovered that there are strong temporal relations and redundancy in the RFID data filtering operations. We incorporated two kinds of caches, tag and filter caches, to make use of this characteristic to improve the efficiency of the filtering engine. The performance of the proposed engine has been examined by implementing a prototype system and testing it. Compared to the basic sequential filter comparison approach, our engine shows much better performance, and it gets better as the number of filters increases.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.2
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• pp.152-167
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• 2018

The high-speed weigh-in-motion system can collect the traveling speed and load information of individual vehicles, which can be used in a variety of ways for the traffic surveillance. However, it has a limit to apply the high-speed weigh-in-motion data directly to a safety analysis because high-speed weigh-in-motion's raw data are point measured data. In order to overcome this problem, this paper proposes a method to calculate the conflict rate and the Impulse severity based on surrogate safety measures derived from the detection time, detection speed, vehicle length, vehicle type, vehicle weight. It will be possible to analyze and evaluate the risk of rear-end collision on freeway traffic. In addition, this study is expected to be used as a fundamental for identifying crash risks and developing policies to enhance traffic safety on freeways.

• Journal of the Korean Association of Geographic Information Studies
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• v.3 no.4
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• pp.11-21
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• 2000

The travel behavior should be analysed microscopically for the traffic management of urban street. The car following theory which found out the correlation between the lead and the following vehicles is being widely used as basic data in many fields. As the vehicle position and its speed information can be received by GPS, this technique is recently applying to the various fields. For the case study the travel data were collected with two vehicles equipped with GPS receiver. The moving distance was calculated by the collected location data every 2 seconds and the speed variation was checked. And this study analysed and compared the acceleration and deceleration speed between the lead and the following vehicle. Finally, Regression model about the relationship between the acceleration and deceleration speed and the acceleration and deceleration distance was constructed. This model could be helpful for the road design and the regulation for the safe traffic management.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.6
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• pp.483-489
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• 2019

For machine learning techniques, a large amount of high-quality material property data should be accumulated. In this study, several data for an alumina tape casting process were produced with the variables of slurry viscosity, gap size, and coating speed. The alumina tapes were manufactured in the range of 1,000~6,000 cps for slurry viscosity, $300{\sim}1,000{\mu}m$ for gap size, and 0.5~2.0 m/min for coating speed. As a result, the lower the viscosity, coating speed, and gap size, the more pore-free tapes could be manufactured. The viscosity of the slurry limited the minimum thickness of the tape. Green sheets with high packing density were manufactured from the slurry of 100~6,000 cps slurry viscosity, coating speed of 0.5 m/min, and a $300{\sim}500{\mu}m$ gap size.

• Korean Journal of Applied Biomechanics
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• v.31 no.3
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• pp.162-167
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• 2021

Objective: This study aimed to identify the different wind speed categories and competitive level among windsurfers through GPS variables to provide the useful information on the development of training programs for enhancing windsurfers' performance. Method: Data from 69 female athletes who participated in 27 races during the 2018-2019 windsurfing season were used for the analysis. Average board speed, total race time, total distance, upwind race time, downwind race time, beam reach race time were collected through GPS. Unconfirmed data were excluded along with penalty point data. The wind conditions were classified as light, light to medium, medium, medium to heavy, and heavy wind, the competitive levels were classified as level 1, level 2, and level 3. Results: As for the average board speed, the level 1 or level 2 group showed higher board speed than the level 3 group in all wind conditions except for the light wind. The total race time and upwind race time showed less time in level 1 or level 2 group than level 3 group in all wind conditions. The total distance, downwind race time and beam reach race time showed less distance and time in level1 group than level 3 group under sufficient wind conditions. Conclusion: Our results show that the aerobic capacity to sustain pumping during upwind course in wind conditions below 15 kts effects performance. In wind conditions of 15 kts or more, indicated that the board control for the fast board speed and small distance required during up, down, beam reach courses had an effect on competition performance. This information can be provided to windsurfers and coaching as basic data for training programs to improve performance.

• Journal of the Society of Disaster Information
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• v.15 no.1
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• pp.76-83
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• 2019

Purpose: The purpose of this study is to present data of density and speed through the experiment of the counterflow by firefighter in corridor. Method: Experimental setup including a corridor in building was prepared for measuring data with 1.5m and 2m width. Normal flow and counterflow were created for each. Data were measured using camera and acquired by video image analysis. Results: The counterflow in corridor resulted in increasing average density of about $0.55P/m^2$ and decreasing average movement speed of about 0.61 m/s. These data measured during the time when the counterflow occurred. Conclusion: It was found that counterflow by firefighter in corridor momentary increasing the density and decreasing walking speed of evacuee. Further experiments of the counterflow effect in the total evacuation time are needed.

• Journal of Korean Society of Steel Construction
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• v.18 no.1
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• pp.47-51
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• 2006

Measuring the track geometry of a high-speed railway is the most important task in track construction and track maintenance work. Measuring accuracy is particularly sign the formulation of the maintenance plan and in the assessment of the work quality, and because it can set the train speed limit. To determine the track geometry of a high-speed railway, it is important to use KNR's track recording coach (EM-120). According to the result of the spectrum analysis, noise near the 1-m wave band was found on the track recording data. A new filter was thus applied to remove the noise from the track recording data. A similar result can be acquired when this method is used in real track geometry.