• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3A
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• pp.240-247
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• 2008

In this paper, we propose a digitally implementable synchronization method for the UWB system. This is achieved by manipulating the frequency components of a synchronizing signal which is the sequence of pulses of periodicity. We analyze the dependancy of the number of pulses and pulse interval on the intrinsic synchronization accuracy. Moreover, through the computer simulation, the performance of the proposed method is examined via varying system parameters.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.3
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• pp.453-460
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• 2010

For high quality image acquisition, compensating air-vehicle motion is essential for airborne SAR system. This paper describes a timing control based motion compensation method for airborne SAR system. Efficient timing control is critical for SAR system since it maintains many timing signals and timing setting for the signals should be updated frequently. This paper proposes Timing Cluster method as an efficient means for timing control of SAR system. Moreover, this paper suggests a simple and efficient method to compensate air-vehicle motion based on the Timing Cluster method. Timing Cluster method enables SAR system to control the timing in a timing noncritical way just maintaining little amount of information.

• Proceedings of the KIPE Conference
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• 2002.11a
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• pp.25-28
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• 2002

In this paper, 2 phase modulated SRPP-PWM(Separately Random Pulse Position PWM) is proposed. This PWM technique is based on the 2 phase modulated SVPWM(Space Vector Pulse Width Modulation). In according to the theory of SVPWM, 2 phase modulated SVPWM uses two pulses, not three pulses as in 3 phase modulated SVPWM. In the proposed SRPP-PWM scheme, each of two phase pulses is located randomly in each switching interval. The experimental results show that the voltage and switching noise harmonics are spread to a wide band area. Also, the performance of the proposed 2 phase modulated SRPP-PWM and the conventional SVPWM are compared to each other In result, the speed response is nearly similar to each other from the viewpoint of the v/f constant control.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.6
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• pp.1091-1096
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• 2011

The main factors of radar signals used in electronic warfare are Radio Frequency(RF), Pulse Repetition Interval(PRI), Pulse Width(PW), Scan Parameter(SP) and so on. This radar signals may have some important information for the electronic warfare. So, there is a necessity for making a threat database to decide whether the radar signal is a threat or not. When the electronic support system collects some threat radar signals, it needs the search band to control the receivers and filter banks of the system. In this paper we propose search band implementation considering the type and center frequency of the receivers of the electronic support system.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.16 no.2
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• pp.59-70
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• 2012

Objectives : Pulse diagnosis by Expert is the only way to classify 8 Constitutions so the study to supplement classifying method by the questionnaire has developed and modified and ECM-32 System has designed in 2010. But analyzing with Decision tree had many nodes and 32 important questions omitted while processing the data. So this study was to classify the 8 constitution patients into 2 groups first and analyze its characters in consecutive order. Methods : The participants of this study were 1027 patients who classified into one of the 8 constitutions according to pulse diagnosis and answered 251 questionnaires in 2010. They were divided into sympathetic nerve acceleration constitution and parasympathetic nerve acceleration constitution and analyzed with decision tree. Results : The reponses of the questionnaire were analyzed with 4 methods of 5 scales interval method from 0 to 5, Na, Low(1,2), Medium(3), High(4,5), average value, Y/N dichotomy. Average Value had no significance. 1. From the 5 scale interval method 6 questionnaires with 7 nodes (F5e, B1d, F7f, F2a, F1b, C4L) were significant. The accuracy was 92.5%. 2. From L, M, H method 7 questionnaires with 7 nodes(F5e, B1d, F7f, F1a, B1c, C4L, P3d) were significant. The accuracy was 92.5%. 3. From Y/N dichotomy 9 questionnaires with 9 nodes( F5e, B1d, F7f, F1a, B1c, C4L, B1b, P1i, B2a) were significant. The accuracy was 93.18%. Conclusions : Based on this study, Yes or No dichotomy method was most significant and categorized among the 4 methods. Unlike previous studies which used interval scale method only, Y/N dichotomy method was more statistically significant with the questionnaire to supplement the method of pulse diagnosis. For further study by analyzing decision tree method in consecutive order, the patients can be divided into 8 Constitutions with higher significance with less questionnaires.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2879-2882
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• 2003

Obstructive Sleep Apnea(OSA) is a representative symptom of sleep disorder which is caused by airway obstruction. OSA is usually diagnosed through the laboratory based Polysomnography(PSG) which is uncomfortable and expensive. In this paper, the detection method for OSA events, using ECG, has been developed. The proposed method uses the ECG data sets provided from Physionet. The features for OSA events detection are the average and standard deviation of 1 minute R-R interval, power spectrum of R-R interval and S-pulse amplitude from data sets. These features are applied to the input of Neural Network. To evaluate the method, we used the another ECG data sets. And we achieved sensitivity of 89.66％, specificity of 95.25％. So, we can know that the features proposed in this paper are important to detect OSA.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.65.4-65
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• 2002

In this paper, RSF+RPP(Random Switching Frequency Ran-domized Pulse Position) PWM for three-phase voltage-controlled inverter is proposed. The LLPWM(Lead-Lag PWM) technique is that three switching pulses are located randomly back and forth in each switching interval But with the restriction of random distribution, the harmonic spectrum cannot be dispersedly and continuously distributed. To tackle this problem , First, the switching frequency is varied randomly. Next, the duty ratio is calculated under the first circumstance. Finally, the switching pulses are located randomly in the switching interval. To verify the validity of the proposed technique, Simulation Study is tried Using Matlab/Si...

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.3
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• pp.230-238
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• 2003

In this paper, Inverter drives adopting 2 phase space vector SRP-PWM (Separately Randomized Pulse Position PWM) with fixed switching frequency is proposed. The proposed 2 phase space vector SRP-PWM scheme is based on the 3 phase SRP-PWM. In the proposed SRP-PWM scheme, each of two phase pulses is located randomly in each switching interval. The experimental results show that the voltage and acoustic noise harmonics are spread to a wide band area. Also, the performance of the proposed 2 phase SRP-PWM and the conventional center aligned SVM are compared to each other. In result, the speed response is nearly similar to each other from the viewpoint of the v/f constant control.

• Journal of the Korean Institute of Navigation
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• v.19 no.4
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• pp.1-8
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• 1995

Although ship's draught information onboard is substantial for both the safety of navigation and the estimation of loaded cargoes, its accuracy depends, in conventional surveying method, on the skillfulness of observers and the condition of the sea surface round the vessel. To obtain more accurate information accessibly, measuring instruments with sophisticated sensors such as mechanical, electronic and ultrasonic transducers have been developed. However, they have still limitation in accuracy and in making up a system due to the complexity of processing signal. In this paper, we propose a new technique for analyzing ultrasonic pulse signal, in order to improve the measurement accuracy and simplify a remote sensing system of draught by ultrasonic waves. In this technique, pulse signal is translated into phase curve which is composed of the phase value defined in time domain. Then, the time interval between two signals different in waveform, is waveform, is analytically determined by calculating average time difference on phase curves. Also, analytical procedure can be carried out in real time with the successive five data sampled at T/4, for high speed digital processing with computer and A/D converter. This technique is useful for measuring draught under the influence of sea condition and for interfacing its data briefly to the integrated bridge system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.12
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• pp.1100-1107
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• 2015

In this paper, we propose an algorithm to identify Wobble PRI and Sinusoidal PRI among Radar pulses. We applied not only the DTOA(Difference Time Of Arrival) concept of radar pulse signals incoming to antennas but also a rising and falling cub characteristic of those PRIs. After making a program by such algorithm, we input each 40 data to Wobble PRI's and Sinusoidal PRI's identification programs and in result, those programs fully processed the data the according to expectations. In the future, those programs can be applied to the ESM, ELINT system.