• Korean Journal of Bronchoesophagology
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• v.1 no.1
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• pp.109-115
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• 1995

High frequency Jet ventilation (HFJV) via cricothyroid membrane puncture contols frequency of ventilation as 20-200/min and persuits adequate gas exchange. HFJV was known to have advantages such as improvement of PaO$_2$, lesser barotrauma, stable hemodynamic effects, good operative field and lesser movement of head. The purpose of this study was to clarify the advantages of HFJV in cases of microlaryngeal surgery which operating time was expected even within 30 minutes. Twenty-eight patients were divided two groups : 1)control group : general endotracheal Intubation anesthesia. 2)experimental group : HFJV via cricothyroid membrane puncture with intravenous anesthesia, frequency 40/min, I/E ratio 40%, driving pressure 40 psi. We analyzed blood pressure, arterial blood gas, score of general condition and recovery time after operation. In conclusion, HFJV via cricothyroid membrane puncture had a good score of general condition and rapid recovery of consciousness, although some accumulation of P$CO_2$and elevation of blood pressure.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.19 no.2
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• pp.263-271
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• 2006

Objective : This study describes the cases of sensorineural hearing loss (SSNHL) patients with marked or complete recovery. Methods : Three patients received oriental medical treatments continuously for more than 1 month and measured the hearing recovery. For diagnosis on these cases, pure tone audiometry (GSI 38, Welch allyn company) was used. For treatment, acupuncture, herbal-medicine and moxibustion treatment were applied. Results : All patients of this report had the recovery of hearing. In 2 cases, the pure-tone 5 frequency (0.25, 0.5, 1, 2, 4 KHz) average improved by more than 35 dB (Marked recovery). In 1 case, it was within the normal limits after oriental medical therapy (Complete recovery). In addition, tinnitus and vertigo decreased in all patients. Conclusions : We may expect that the oriental medical therapy improvers the hearing recovery in the patients of SSNHL.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.4
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• pp.568-576
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• 2017

This paper presents a clock and data recovery circuit with an adaptive loop bandwidth calibration scheme and the idle power saved frequency acquisition. The loop bandwidth calibration adaptively controls injection currents of the main loop with a trimmable bandgap reference circuit and trains the VCO to operate in the linear frequency control range. For stand-by power reduction of the phase detector, a clock gating circuit blocks 8-phase clock signals from the VCO and cuts off the current paths of current mode D-flip flops and latches during the frequency acquisition. 77.96% reduction has been accomplished in idle power consumption of the phase detector. In the jitter experiment, the proposed scheme reduces the jitter tolerance variation from 0.45-UI to 0.2-UI at 1-MHz as compared with the conventional circuit.

• Journal of IKEEE
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• v.23 no.3
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• pp.858-864
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• 2019

A clock system is proposed to eliminate data loss due to frequency difference between sensor nodes in a sensor utility network. The proposed clock system for each sensor node consists of a bust clock-data recovery (CDR) circuit, a digital phase-locked loop outputting a 32-phase clock, and a digital frequency synthesizer using a programmable open-loop fractional divider. A CMOS oscillator using an active inductor is used instead of a burst CDR circuit for the first sensor node. The proposed clock system is designed by using a 65 nm CMOS process with a 1.2 V supply voltage. When the frequency error between the sensor nodes is 1%, the proposed burst CDR has a time jitter of only 4.95 ns with a frequency multiplied by 64 for a data rate of 5 Mbps as the reference clock. Furthermore, the frequency change of the designed digital frequency synthesizer is performed within one period of the output clock in the frequency range of 100 kHz to 320 MHz.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.7
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• pp.1214-1220
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• 2010

This paper proposes an efficient under frequency relay load shedding scheme for the korea power system which is more than two times than the system size and its capacity of the power system 10 years ago. The proposed method is keeping the power system stability and supports for the operating system during critical situations such as big disturbances and unstable in supply and demand. In order to determine the number of load shedding steps, the load to be shed per step, and frequency level, it is necessary to investigate and analyze maximum losses of generation due to the biggest contingency, maximum system overload, maximum keeping frequency, maximum load to be shed, and recovery frequency. The proposed method is applied to Off-peak load(25,400MW) and Peak load(62,290MW) of Korea Electric Power Corporation to demonstrate its effectiveness.

• Journal of Korean Academy of Nursing
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• v.2 no.1
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• pp.49-61
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• 1971

The purpose of this study is to observe the administering of analgesics and sedatives to cases of surgery, the influence of the patients'situational variables on the use of these drugs, and the required number of recovery days in relation to the patients'situational variables and general conditions. Fifty patients in the age range of 15 through 65 who had undergone general surgery at Seoul national University Hospital. Woo Sok University Hospital and Koryo Hospital between May and August of 1971 were chosen for this study. They were observed with regard to the frequency of postoperative uses of analgesics and sedatives age, the required period of recovery in comparison with the situational variables of patients such as sex, age, marital status, the type and duration of anesthesia, experience of previous operation, history of other diseases, preoperative period of hospitalizations and the general conditions of patients such as sleep, stomach condition, bowel condition, urination, interest in surroundings, strength and energy, self-assistance and appetite. The study results were reviewed in a statistical method to obtain the following findings: 1. There was a significant decrease in the frequency of analgesic uses according to the number of days passed after operation. 2. The mean postoperative recovery days were 5.31 days and mote than half of the patients have never used analgesics until recovery. 3. There was a significant decrease in the frequency of sedative uses according to the number of days passed after operation. 4. The rank-order correlation between the frequency of analgesic use and that of sedative use following surgery observes in relation to the number of postoperative days was a low and negative one. 5. All of the patients except one hate used sedatives only once a day for the whole recovery period. 6. The longer they stayed in the hospital before surgery, the less have they used analgesics after surgery. 7. There were significant differences in use of analgesics after surgery by age groups; the 25-44 age group used more analgesics than the 15-24 and 45-65 age groups. 8. There were no significant differences in use of analgesics after surgery by all situational variables except the number of days of hospitalization and age. 9. The longer they stayed in the hospital before surgery, the earlier have they recovered from the surgery. 10. There were no significant differences in the number of required recovery days by all situational variables except the length of preoperative hospitalization. 11. There were no significant differences in the number of required postoperative recordedly days by the general conditions of patients.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.5
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• pp.640-645
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• 2012

DC-DC converter and DC-AC inverter in a hybrid electric vehicle (HEV) generate the switching noise. It may be generated by the reverse recovery operation of the power diode in the switching circuit of the converter or the inverter. The shape of the reverse recovery region may be determined by both reverse time and recovery time in the diode. So, in this paper, the frequency spectrum of switching noise was estimated by the shape of the reverse recovery region and compared with the measured results. It shows that the meaningful region of the frequency spectrum is directly related with the reverse time.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.251-255
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• 1997

The conventional high frequency phase-shifted full bridge dc/dc converter has a disadvantage that a circulating current flows through transformer and switching devices during the freewheeling interval. Due to this circulating current, RMS current stress, conduction losses of transformer and switching devices are increased. To alleviate this problem, this paper provides a circulating current free type high frequency soft switching phase-shifted full bridge (FB) dc/dc converter with energy recovery snubber (ERS) attached at the secondary side of transformer. The energy recovery snubber (ERS) adopted in this study is consisted of three fast recovery diode(Ds1, DS2, Ds3), two resonant capacitor (Cs1, Cs2)

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1219-1225
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• 2001

In this Paper we describe the design of synchronization algorithms for burst QPSK receiver, which are applicable to BWLL uplink. The demodulator consists of digital down converter, matched filter and synchronization circuits. For symbol timing recovery we ufo Gardner algorithm. And we use forth power method and decision directed method for carrier frequency recovery and phase recovery, respectively. For the sake of performance analysis, we compare simulation results with the board implemented by FPGA which is APEX20KE series chip for Alter. The performance results show it works quite well up to the condition that a frequency offset equal to 4.7% of symbol rate.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.6
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• pp.1043-1048
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• 2011

In this paper, a newsynchronization technique applied to burst-mode communication is proposed. A synchronization technique is to estimate carrier frequency and phase offsets in a noisy channel environment. A fundamental problem for estimating the parameters(carrier phase and frequency offsets) in burst-mode transmission is that the ways of pursuing estimation accuracy and transmission efficiency are always trade-off. To solve this problem, a new carrier recovery technique is proposed to improve the transmission efficiency with reliable performance especially at low S/N. In the proposed technique, the synchronization parameters are first estimated based on a data-aided feed-forward estimation scheme. Then, a phase tracker using decision-directed DPLL estimates the phase offset for the data portion of the burst data. From simulation results, it shows fast synchronization with shorter preamble maintaining reasonable BER performance at low S/N.