• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.8
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• pp.767-773
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• 2008

Galileo is a new civil Global Navigation Satellite System(GNSS) developed by Europe. GIOVE-A, a satellite to test Galileo system performance, transmits navigation signal on orbit. Evaluation of Galileo system and development of Galileo receiver needs to analyze GIOVE-A signals. In this paper, we received GIOVE-A signals and processed it using GIOVE-A Interface Control Document(ICD). Signal acquisition, tracking and navigation message decoding made grasping current signal status possible. Bandwidth increase by BOC modulation is one of the difference from GPS. Therefore, we investigated feasibility of conventional GPS L1 RF front-end to receive GIOVE-A E1 signal by evaluation of receiving performance of navigation signal on each bandpass filter of RF front-end.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.6
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• pp.1-10
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• 2019

Traffic Signal Evaluation HILS is a system designed to evaluate a traffic signal system, and has a function of driving that simulates a real environment using a simulator that simulates a real traffic signal environment and an LCS that simulates a traffic signal controller. This study simulates the function of the traffic signal controller and is designed for design the LCS which is connected to the center system and the traffic simulator (VISSIM). The design of the LCS program uses a portable python language, and the code is designed in two versions running on Windows in the PC environment and unning on embedded environment, with a slight modification of the code. In this study, we analyzed the limitations of using LCS on Windows in PC environment and confirmed the ease of simulation Linux in embedded environment at large capacity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2745-2752
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• 2014

In recent years, Transport Demand Management has been conducted for the efficient management of transport. In ITS applications in particular, the prerequisite is accurate and reliable positioning. However, the major problems are satellite signal outage, and multipath. This paper proposes that outage and multipath measurement can be detected and estimated using elevation angle and signal to noise ratio data association relation in stand-alone GPS. In order to verify the performance of the proposed method, it is then evaluated by the car test. the evaluation test environment has low accuracy and unreliable positioning because of signal outage or multipath such as steep hill and high buildings. In the evaluation test result, 918times abnormal signal occurred and it was confirmed that the proposed method showed more improved 9.48m(RMS) horizontal positioning error than without proposed method.

• Journal of Advanced Navigation Technology
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• v.23 no.2
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• pp.142-150
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• 2019

Muzzle Velocity is one of the most important measurement items for evaluation of ammunition. The muzzle velocity is defined as the velocity when the projectile leaves the muzzle. Particularly, since the muzzle velocity is closely related to the performance of the propellant, precise measurement of muzzle velocity is required. Doppler radar is used to measure the muzzle velocity, but the quality of Doppler radar signal depends on the test site environment. In this paper, a method to remove the clutter that degrades the signal quality of Doppler radar by improving the structure of the test site and the signal processing method is suggested. For the application of the improved signal processing method, a program for acquiring Doppler radar's raw Doppler data was created. Statistical verification of the velocity data obtained through the improvement of the test site structure and signal processing method proved that the proposed method is effective for the removal of clutter as compared with the existing method.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.5
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• pp.50-57
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• 1994

In the non-destructive evaluation techniques using ultrasonic signal, backscattering noise from grain interface decreases the SNR of received signal. In this paper, SSP(split-spectrum processing) based on the constant FBR decomposition method has been applied to enhance the SNR. This algorithm helps to find optimal parameters of filter bank through a simple theory and has an advantage that reduce the signal processing time compared with the conventional constant bandwidth decomposition method. In this experiment, the 304 stainless steel sample is heat-treated and received ultrasonic signal is processed by SSP using the constand bandwidth decomposition method and the constand FBR decomposition method enhanced the SNR by 1.4 dB and reduced the required number of filters by 4 compared with the constant bandwidth decomposition method.

• Journal of the Korean Society of Safety
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• v.15 no.4
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• pp.134-138
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• 2000

Signal words such as DANGER, WARNING, CAUTION, etc. have been used in order to transmit a potential hazard easily and quickly. But they were applied to a number of the sites without consistency. Thus, this study took Quantification Method and Cluster Analysis in order to judge the signal words corresponding to the urgency of situations, and to analyze whether signal words are used properly or not. According to the result of Quantification Method II signal words were most affected by Understanding, Severity and Likelihood in both student group and industrial worker group. And in Quantification Method III CAUTION corresponded to Immediacy and Understanding whereas NOTICE did to Receptivity, WARNING, DEADLY and DANCER did to Likelihood, Dangerousness and Severity. Finally, Cluster Analysis showed that CAUTION and NOTICE were recognized as similar words.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.572-577
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• 2011

The acoustic emission (AE) technique is a well-known non-destructive test technique, both in research and for industrial applications. It is mainly used to monitor the onset of cracking processes in materials and components. Predicting and preventing the crack phenomenon has attracted the attention of many researchers and has continued to provide a large incentive for the use of condition monitoring techniques to detect the earliest stages of cracks. In this research, goal is in grasping features of AE signal caused by crack growth. The envelope analysis with discrete wavelet transform (DWT) is used to find the characteristic of AE signal. To estimate feature of divided into three by crack length, the time waveform and the power spectrum were generated by the raw signals and the transferred signal processed by envelope analysis with DWT.

• The Journal of the Acoustical Society of Korea
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• v.15 no.1
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• pp.93-101
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• 1996

In this paper, we implement the system for speech processing to provide the subscribers who are using the telephone network with better speech services. We develop the specified board which is processing speech signal and devise the system which carries out storing and replaying the speech signal under the condition that one master board controls multiple DSP(Digital Signal Processing) boards using VME bus. We use CPU30 board as a maste board and develop SPM(Signal Processing Module) board as a DSP board and then evaluate performance of the system.

• Journal of KSNVE
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• v.6 no.4
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• pp.499-502
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• 1996

Interior noise, engine speed and vehicle speed are measured under transient road-load condition and interior noise signal is transformed by using the transient signal analysis methods, such as the spectrogram and wavelet transform. Using the analyzed results, subjective noise metrics such as the loudness, sharpness and articulation index at each vehicle speed can be estimated and characteristics of interior noise for various running modes can be discussed in the viewpoint of noise quality.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2003.06a
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• pp.242-246
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• 2003

본 논문에서는 친사용자 환경의 시뮬레이션 환경을 제공하는 SPW 시뮬레이션 플랫포음을 이용하여 스마트 안테나 CDMA 이동통신 시스템을 구현하여 빔형성에 있어서 고정(non-adaptive)의 경우와 적응(adaptive)의 경우로 나누어 성능 분석을 수행하였다. 특히 적응인 경우는 LS(Least Square) 와 LMS (Least Mean Square) 의 적응 알고리즘을 비교하였으며 간섭 기지국의 각도 (Interferer signal angle) 변화에 따른 성능도 비교하였다. SPW 시뮬레이션 결과, 고정 경우보다는 적응 경우가 3［㏈］이상의 이득을 얻을 수 있었으며 LMS 보다는 LS 의 성능이 우수함을 알 수 있었다.