• Composites Research
• /
• v.18 no.5
• /
• pp.27-33
• /
• 2005

In this research, the mathematical modelling of the pulse-CVI (Chemical Vapor Infiltration) for the preparation of siliconcarbide/carbon composite. Each pulse consists with the gas injection time, the reaction time and the evacuation time. Effects of the reaction time and the evacuation time were studied. Additionally, the effects of the reactant concentration and the pressure were observed. The benefits of the pulse-CVI such as the uniform infiltration of siliconcarbide into the carbon preform and the short reaction time were certified.

• Journal of the Korea Computer Industry Society
• /
• v.2 no.3
• /
• pp.363-368
• /
• 2001

This paper introduced cascading technique as a new technology composed of two pulse transformers and presented the experimental data and results. To obtain the stable pulse voltage adopted cascading technique, we designed and tested a compact pulse generator by adjusting the load resistors and input voltage. Adopting cascading technique to load, we found that average cascading voltage was about 62$\%$ of theoretical value. Cascading ratio was calculated at almost 19 compared with non cascading voltage.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.10A
• /
• pp.987-996
• /
• 2008

In this paper, the conventional anti-collision algorithms, such as Channel Monitoring algorithm and Pulse Protocol algorithm are analyzed. To decrease tag identification time, and increase system throughput and efficiency, we propose a new reader anti-collision algorithm, Pulse Protocol-based Hybrid Reader Anti-collision Algorithm, using Slot-occupied Probability under dense reader environment. The proposed algorithm uses Slot-occupied Probability to improve the performance of Pulse Protocol Algorithm. That is, A reader checks Slot-occupied Probability after generating random backoff time. If Slot-occupied Probability is greater than 0, it uses another new random backoff time to avoid reader collision. We also compare the performance of the proposed algorithm with those of Channel Monitoring and Pulse Protocol algorithms in respect of identification time system throughput, and system efficiency. Simulation results show that the proposed algorithm has an increment of 5% of identification time and system throughput as increasing the number of readers.

• Aerospace Engineering and Technology
• /
• v.8 no.2
• /
• pp.92-97
• /
• 2009

Two conventional speed detection methods (Elapsed-time method and Pulse-count method) are analyzed and compared for a high speed motor with digital tacho pulse with non-uniformity. In general, the elapsed-time method usually has better performance than a pulse-count method in case sufficiently high speed clock is used to measure the time difference. But if a tacho pulse non-uniformity exists in the reaction wheel - most of reaction wheel has a certain amount of non-uniformity - the accuracy of the elapsed-time method is degraded significantly. Thus the performance degradation is analyzed with respect to the level of non-uniformity of tacho pulse distribution and an allowable bound is suggested.

• Journal of Digital Convergence
• /
• v.20 no.4
• /
• pp.411-418
• /
• 2022

The purpose of this study is to investigate the relationship between sleep time and pulse pressure in Korean adults, and the research method used data from the 7th period (2016-2018) of the National Health and Nutrition Examination Survey. Subjects were 5,707 persons aged 20 years or older, and for frequency and percentage continuous data, mean and standard deviation, cross analysis and independent t-test, and stepwise logistic regression analysis for high pulse pressure were performed. SPSS WIN 18.0 version statistical program was used. was used. As a result of the study, the prevalence of hypertension was higher in the overall population (OR=1.344, 95% CI=1.002-1.803) and in women (OR=1.624, 95% CI=1.112-2.371) when sleeping for more than 9 hours compared to less than 6 hours. high, but not significant in males (OR=1.012, 95% CI=0.631-1.550). Therefore, considering the effects of inappropriate sleep time on health, public health education and management are necessary. Further research on the relationship between sleep time and pulse pressure will be needed.

• Journal of the Korean Magnetics Society
• /
• v.21 no.3
• /
• pp.104-107
• /
• 2011

We measured signals at the "Guan" region of a radially arterial pulse using the prototype of a clamping pulsimeter equipped with a Hall effect device, which is passed signals through the voltage detecting hard ware system. The important four different measuring times of the period, systolic, reflective, and notch peaks for a temporally pulse signal are obtained and compared each other from the analysis for an arbitrary pulse wave of one position of small size permanent magnet. It is possible to measure the reproducible pulse rate and blood pressure by using the cuffless clip type pulsimeter without an unpleasant oppressive feeling due to the use of pressurization.

• Proceedings of the KSMRM Conference
• /
• 2002.11a
• /
• pp.15-29
• /
• 2002

MRI에서 펄스 시퀀스(pulse sequence)란 고주파 RF(radiofrequency) 펄스 및 경사자장(gradient) 펄스를 가하고 MR 신호를 획득하는 순서를 시간대별로 도식화 한 pulse diagram을 이야기한다. 이러한 pulse sequence는 실제로 영상을 획득하기 위한 RF amplifier, gradient amplifier 등의 하드웨어를 순차적(sequential)으로 구동하는 역할을 한다. 따라서 이러한 pulse sequence는 현재 임상적으로 사용되는 다양한 영상기법들을 이해하는데 필수적이다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.2B
• /
• pp.151-161
• /
• 2009

The PULSE protocol can greatly reduce power consumption using a node's sleep state. But this protocol does not consider movement of a sink node in a sensor network. In the mobile sensor network a routing protocol must recover path error by movement of a sink node as quickly as possible. Therefore we have to achieve fast path recovery and power saving to support movement of a sink node in a sensor network. This paper proposes the Mobile PULSE protocol which is a improved routing protocol for a mobile sink node. And we evaluate Mobile PULSE and show that the Mobile PULSE reduces the recovery time about 40% compared with original PULSE protocol. Mobile PULSE increases energy consumption than PULSE as a maximum of 0.8%, which means Mobile PULSE is similar to PULSE in energy consumption. This paper shows mobile PULSE's capability in the mobile sensor network through evaluation of path recovery time and power consumption.

• The Journal of the Acoustical Society of Korea
• /
• v.37 no.3
• /
• pp.139-146
• /
• 2018

Monostatic sonar systems localize targets using the time information of pulse transmission and receipt. Whereas, in asynchronous bistatic sonar systems, receivers need to detect direct blast to localize targets, since a source doesn't share pulse information with receivers. In this paper, we propose a direct blast detection algorithm, which estimates PRI (Pulse Repetition Interval) of direct blast and adaptive thresholds. Experimental results show the proposed algorithm has robust direct blast detection performance in the environment where strong background noise and target signal exist.

• Korean Journal of Optics and Photonics
• /
• v.11 no.2
• /
• pp.102-107
• /
• 2000

We propose a new scheme for generating a pedestal-free, femtosecond soliton pulse train by utilizing quasI-adiabatic high order soliton pulse evolution in dispersion decreasing fiber in conjunction with the intermediate pedestal suppression stage. Compression factor over 280 was achieved from lOGHz sinusoidal input, to 176 is soliton pulse train. train.