• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.10
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• pp.1493-1500
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• 2015

For efficient and economical train operation in low-density railway line, on-board oriented train control system, which reduces expensive wayside equipment, is being developed. In this paper, we discuss a tram signal priority strategy which enables efficient and safe train operation when the developing system is applied to train-tram railway environment. Based on the well-known transit signal priority strategies, we develop a tram signal priority algorithm and conduct simulations by using model-based systems engineering (MBSE) tool. Various considerations such as operation procedure, linkage to existing road traffic system, applicability with respect to crossroad types, and so on, are also dealt with.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.1
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• pp.162-171
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• 2017

Low frequency noise components causes the baseline drift in the ECG signals. In this paper, a morphological operation and smoothing spline technique are used for ECG signal processing in order to accomplish baseline correction. Removing the baseline drift from ECG signal using morphology operation, the feature of original signal may be distorted. To resolve this distortion problem, we applied a smoothing spline operation after morphology operation. In order to compare with existing morphology operation method for baseline correction, we apply proposed method to ECG data in MIT/BIH database. Compared to other existing method, our proposed method achieved low data distortion on the original signal.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.148-150
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• 1988

The output characteristics of VSI by transistor depend upon bias signal with drive circuit. As the CTI is one of the VSI, takes case PWM output voltage. This Inverter operation is based upon position and negative of sinusoldal PWM signal by carrier triangular wave and compared sine one. Besides, the Inverter operation system required digital signal for microprocessor, sampling method of Inverter driver signals study for get rid of generated signal is error. In the paper, the method of 3 level PWM signal for CTI was studied. This method of signals depend upon caculated switching position of natural sampling with $10^{-6}$ modulation error for time flowchart programs.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.8
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• pp.1064-1069
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• 2014

The railway signalling system plays an essential role in the headway and routing control for a safe and efficient train operation. The reliable and safe operation of the system is very important because the failure of the railway signalling system can lead to the collision, derailment, or unexpected stop of a train. So far, the conventional wayside signal mode (ATS: Automatic Train Stop) has been generally used as the railway signalling system. However, this system is highly linked to a risk of major accidents resulted from human mistakes such as missing a signal or careless control of train speed. Accordingly, the onboard signal mode (ATC: Automatic Train Control) as an alternative of ATS has been recently introduced and applied to transmit effectively the information on speed control of a train by using computers and communication equipment. In the process of replacing the obsolete signal system, it is necessary to switch over the system while providing passengers with normal services. Therefore, the integration of a railway signaling system compatible for both ATS and ATC and its interface is discussed in this study. In particular, the implementation scenario required for operation planning of the integrated system was designed, and the results as well as effects of its applicability test were also presented.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1054-1060
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• 2010

LRT(Light Rail Transit) is currently adopting a more upgraded signal system these days. This latest signal system is a train on-board signal system with moving block based on the realtime bi-directional wireless communications. The system applies RF-CBTC(Radio Frequency - Communication Based Train Control System) in order th execute fully automated manless operation. This paper reviews the performance requirements and safety of RF-CBTC that will be applied to the fully automated manless operation for LRT.

• Journal of Biomedical Engineering Research
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• v.17 no.2
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• pp.209-214
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• 1996

The display of biological signals in raster scan monitors often involves a multirate sampling operation which consists of decimation .and interpolation. All electroencephalouaphic (EEG) samples of 10 to 30 seconds (2, 500 to 7, 500 samples at 250[Hz] sampling frequency) must be displayed in the computer screen to keep the aspect ratio of the paper polygraph output. Since the current afrorclable display technology Plots at most 2, 000 Pixels Per row, sDme signal samples need to be discarde4 This Paper studies methods to perform this operation characterizing them from the signal processing viewpoint and compares the display quality among several decimation techniques. Experimental results show that a nonlinear operation such as the peak detection method could be preferable to the canonical linear filtering to reduce aliasing.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.11
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• pp.3789-3809
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• 2014

Radio environment maps (REMs) and geolocation database represent an important source of information for the operation of cognitive radio networks, replacing or complementing spectrum sensing information. This paper provides a survey of methods for constructing the radio frequency layer of radio environment map (RF-REM) using distributed measurements of the signal levels at a given frequency in space and time. The signal level measurements can be obtained from fixed or mobile devices capable of sensing radio environment and sending this information to the REM. The signal measurements are complemented with information already stored in different REM content layers. The combined information is applied for estimation of the RF-REM layer. The RF-REM construction methods are compared, and their advantages and disadvantages with respect to the spatial distribution of signal measurements and computational complexity is given. This survey also indicates possible directions of further research in indirect RF-REM construction methods. It emphasizes that accurate RF-REM construction methods should in the best case support operation with random and clustered signal measurements, their operation should not be affected by measurements outliers, and it must estimate signal levels comparably on all RF-REM locations with moderate computational effort.

• Journal of the Ergonomics Society of Korea
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• v.28 no.3
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• pp.63-71
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• 2009

A car navigation system as an in-vehicle route guidance information (RGI) offers a state-of-the-art technological solution to driver navigation in an unfamiliar area. However, the RGI is provided by some pre-determined options in terms of the interface between a driver and a car navigation system. Drivers occasionally pass the target intersection owing to non- or late- recognizing it. This paper is examined the position of driver's turn signal operation and intersection recognition approaching at the target intersection which is difficult to identify, as a fundamental research on developing the additional RGI connecting with the turn signal control. The field experiment was conducted to measure distances of the turn signal operation and the intersection recognition from the target intersection according to left turns, right turns, and landmarks at adjacent intersection. And glance behavior to the car navigation display was evaluated by using an eye camera. The results of the field study indicate that, most case of driving, drivers operate the turn signal until 40m to 50m before coming to the target intersection. The driving simulator experiment was performed to examine the effectiveness of providing the additional RGI when drivers did not operate the turn signal approaching at the target intersection based on the results of the field study. To provide the additional RGI is effective for the intersection identification and recognition, and expected to improve the traffic safety and the comfort for drivers.

• Current Optics and Photonics
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• v.2 no.5
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• pp.413-421
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• 2018

We propose a novel methodology based on the multiplication function to improve the signal-to-noise ratio (SNR) for vibration detection in a phi optical time-domain reflectometer system (phi-OTDR). The extreme-mean complementary empirical mode decomposition (ECEMD) is designed to break down the original signal into a set of inherent mode functions (IMFs). The multiplication function in terms of selected IMFs is used to determine a vibration's position. By this method, the SNR of a phi-OTDR system is enhanced by several orders of magnitude. Simulations and experiments applying the method to real data prove the validity of the proposed approach.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.6
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• pp.127-136
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• 2013

In order to improve the safety and efficiency of traffic signal operation, several core projects of advanced transportation operating systems were implemented in Changwon City. This project included 10 units such as the expansion of roundabout, the permitted left-turn signal operation and the effectiveness of the projects was assessed using before and after studies. This paper presented the quantitative and qualitative evaluation results for three projects: roundabout, permitted left-turn signal operation, and left-turn actuated signal operation. From the analysis results, average travel speed was improved by 16.8% from the installation of roundabouts and average travel time and control delay were reduced by 12.4% and 41.6% respectively, from permitted left-turn operation. It was found that average control delay was reduced about 26.7% from left-turn actuated signal operation. In addition, more than 57.7% of the surveyed people was satisfied with the operational performance of the roundabout implemented. It is expected that the operational performance of traffic signal can be greatly improved by incorporating the proper projects of advanced transportation operating systems in other cities.