• Science of Emotion and Sensibility
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• v.14 no.1
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• pp.147-156
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• 2011

Basic emotions such as happiness, sadness, anger, fear, and disgust have been widely used to investigate emotion-specific autonomic nervous system activity in many studies. On the contrary, surprise emotion, Suggested also as one of the basic emotions suggested by Ekman et al. (1983), has been least investigated. The purpose of this study was to provide a description of cardiovascular responses on surprise stimulus using electrocardiograph (ECG) and photoplethysmograph (PPG). ECG and PPG were recorded from 76 undergraduate students, as they were exposed to a visuo-acoustic surprise stimulus. Heart rate (HR), standard deviation of R-R interval (SD-RR), root mean square of successive R-R interval difference (RMSSD-RR), respiratory sinus arrhythmia (RSA), finger blood volume pulse amplitude (FBVPA), and finger pulse transit time (FPTT) were calculated before and after the stimulus presentation. Results show significant increase in HR, SD-RR, and RMSSD-RR, decreased FBVPA, and shortened FPTT. Evidence suggests that surprise emotion can be characterized by vasoconstriction and accelerated heart rate, sympathetic activation, and increased heart rate variability, parasympathetic activation. These results can be useful in developing an emotion theory, or profiling surprise-specific physiological responses, as well as establishing the basis for emotion recognition system in human-computer interaction.

• Tuberculosis and Respiratory Diseases
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• v.70 no.6
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• pp.498-503
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• 2011

Background: The causes of exertional desaturation in patients with COPD can be multifactorial. We aimed to investigate factors predict exertional desaturation in patients with moderate to severe COPD. Methods: We tested 51 consecutive patients with stable COPD (FEV1/FVC, $40{\pm}13%$ predicted). Patients performed a six minute walk test (6MWT). Pulse oxymetric saturation (SpO2) and pulse rate were recorded. Results: Oxygen desaturation was found in 15 subjects after 6MWT, while 36 subjects were not desaturated. Lung diffusing capacity was significantly lower in desaturation (DS) group ($62{\pm}18%$ predicted) compared with not desaturated (ND) group ($84{\pm}20$, p<0.01). However there was no statistical difference of FEV1/FVC ratio or residual volume between two groups. The pulse rate change was significantly higher in the desaturated compared with the not desaturated group. Six minute walking distance, subjective dyspnea scale, airflow obstruction, and residual volume did not predict exertional oxygen desaturation. Independent factors assessed by multiple logistic regression revealed that a pulse rate increment (odd ratio [OR], 1.19; 95% confidence interval [CI], 1.01~1.40; p=0.02), a decrease in baseline PaO2 (OR, 1.105; 95% CI, 1.003~1.218; p=0.04) and a decrease in lung diffusing capacity (OR, 1.10; 95% CI, 1.01~1.19; p=0.01) were significantly associated with oxygen desaturation. Receiver operator characteristic (ROC) analysis showed that an absolute increment in pulse rate of 16/min gave optimal discrimination between desaturated and not desaturated patients after 6MWT. Conclusion: Pulse rate increment and diffusion capacity can predict exertional oxygen desaturation in stable COPD patients with moderate to severe airflow obstruction.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.3
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• pp.41-46
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• 2011

The tire damage classification method is researched by periodicity detection of ultrasonic envelope signals to occur at the driving vehicle tire. Because periodic signals is generated by rotations of the damaged tire, it should convert to pulse for using the density function. After time intervals of pulses are represented by the density function, the dominant periodicity is detected. The threshold to make a pulse is calculated by moving average of envelope signals. The result of time density function in case of one damage material, the first peak's time is equals to tire's rotation period, 162ms and 102ms, about the speed of 50km/h and 80km/h. In case of more than one damage material, the sum of each peak's time is equals to tire's rotation period about the speed.

• Journal of Environmental Science International
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• v.26 no.6
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• pp.779-788
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• 2017

In this study, we analyzed the changes in the echolocation and prey-capture behavior of the horseshoe bat Rhinolophus ferrumequinum from search phase to capture time. The experiment was conducted in an indoor free-flight room fitted with an ultra-high-speed camera. We found that the bats searched for food while hanging from a structure, and capturing was carried out using the flight membrane. In addition, it was confirmed that the mouth and uropatagium were continuously used in tandem during the capturing process. Furthermore, using Constant Frequency (CF), we confirmed that the prey catching method reflected the wing morphology and echolocation pattern of R. ferrumequinum. The echolocation analysis revealed that the pulse duration, pulse interval, peak frequency, start-FM-bandwidth, and CF duration decreased as the search phase approached the terminal phase. Detailed analysis of echolocation pulse showed that the end-FM bandwidth, which increases as it gets nearer to the capture time of prey, was closely related to the accurate grasp of the location of an insect. At the final moment of prey capture, the passive listening that stopped the divergence of the echolocation was identified; this was determined to be the process of minimizing the interruption from the echo of the echolocation call emitted from the bat itself and sound waves emitted from the prey.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1257-1264
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• 2019

The traditional cuff-based method for BP(Blood Pressure) measurement is not suitable for continuous real-time BP measurement techniques. For this reason, the previous studies estimated various blood pressures by fusion with the electrocardiography (ECG) and photoplethysmogram (PPG) sensor signals. However, conventional techniques based on PPG bio-sensing measurement face many challenging issues such as noisy supply fluctuation, small pulsation, and drifting non-pulsatile. This paper proposed a novel BP estimation methods using PPG and ECG sensors, which can be derived from the relationship between PPG and ECG using PTT(Pulse Transit Time) and PWV(Pulse Wave Velocity). Unlike conventional height ratio features, which are extracted on the basis of the peaks in the PPG and ECG waveform. The proposed method can be reliably obtained even if there are missing peaks among the sensed PPG signal. The increased reliability comes from periodical estimation of the peak-to-peak interval time using ECG and PPG. After 250,000 times trials of the blood pressure measurement, the proposed estimation technique was verified with the accuracy of ±28.5% error, compared to a commercialized BP device.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.47-54
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• 2007

Since impulse-radio-based ultra wideband (IR-UWB) do not use carrier frequency but use very short pulse to transmit data it sends data not continuously but discretely and this feature gives the potential to reduce collision in multi-user environment. In this paper, we analyse characteristic of IR-UWB and propose a new collision paradigm, Collision Distribution which changes collision level from packet to pulse. In Collision Distribution mechanical each node sends data with its own pulse interval in random time, distributed manner. It prevents packet drop due to packet collision. We show that Collision Distribution can reduce packet error and can provide real time packet transmission with analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.6
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• pp.611-619
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• 2016

Success in modern war depends on electronic warfare. Therefore, It is very important to identify the kind of Radar PRI modulations in a lot of Radar electromagnetic waves. In this paper, I propose an algorithm to identify Linear up Sliding PRI, Non-Linear up Sliding PRI and Linear Down Sliding PRI, Non-Linear Down Sliding PRI among many Radar pulses. We applied not only the TDOA(Time Difference Of Arrival) concept of Radar pulse signals incoming to antennas but also a rising and falling curve characteristics of those PRI's. After making a program by such algorithm, we input each 40 data to those PRI's identification programs and as a result, those programs fully processed the data in according to expectations. In the future, those programs can be applied to the ESM, ELINT system.

• Korean Journal of Ecology and Environment
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• v.49 no.4
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• pp.385-392
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• 2016

Geographical isolation may lead to the populations having different ecological characteristics. Geographic isolation have been known to cause echolocation call differences in bats. In order to look at geographic differences of echolocation calls of Great Horseshoe Bats (Rhinolophus ferrumequinum), populations of inland and Jeju island habitats were examined in Korea. The study areas were some abandoned mines in the inland and caves of Jeju island, which were known as rest sites of Great Horseshoe Bats during the active season. Recording was done in two ways: Hand-held, Free-flying. Recording pulse was analyzed into five parameters: Maximum Frequency (FMAX), Minimum Frequency (FMIN), Peak Frequency (PF), Duration (D), Inter pulse Interval (IPI). Interestingly, The present study shows that the difference in echolocation between the inland and island populations. The PF of bats inhabited inland was 69 kHz. but, the PF of bats inhabited island (Jeju) was 71 kHz. There was a difference between regions. Discriminant analyses also showed clear difference between the inland and the island populations. Especially, PF of Korea population is lower than that of Europe (82 kHz) and higher than that of Japan (65 kHz).

• Journal of IKEEE
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• v.25 no.4
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• pp.721-727
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• 2021

This paper proposes a UWB (Ultar-wideband) impulse generator using the gated ring oscillator. The oscillator and PLL circuits which generate a several GHz LO signal for the conventional architecture are replaced with the gated ring oscillator. Therefore, the system complexity is decreased. The proposed architecture controls the duty of enable signal, which is used for the head switch of ring oscillator. The control of the duty enables to tun off the oscillator during the guard interval and stop wasting the power consumption. The pulse shaping method using the counter makes the small side lobe and preserves the bandwidth regardless of the change on the center frequency. Designed UWB impulse generator could change the center frequency from 6.0 GHz to 8.8 GHz with a digital bit control, while it preserves the bandwidth as about 1.5 GHz.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.10
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• pp.83-88
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• 2012

The pitch searching is a very important process in a vocoder. Generally, the method of pitch searching method is used by highlighting the periodicity, where a correlation is identified with the signal by changing the interval of two pulses. When the correlation value is highest, the pitch can be found by the pulse interval because it is the repetition interval with most striking period. There are many methods to solve this problem and search the pitch by dividing a frame into many subframes, but there is too much calculation to solve. A method in this paper is suggested to vary the number of subframes by predicting the amplitude change rate in a frame. If this method is applied, the general pitch searching performance will be improved because the accuracy may be enhanced without affecting the sound quality in the synthesized signal after parameter transmission; and the pitch searching time may be reduced.