• 대한전자공학회논문지SD
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• 제43권9호
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• pp.38-43
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• 2006

CMOS image sensor는 집적회로 구현이 가능하여 사이즈를 줄일 수 있고 저전력으로 구현이 가능하며 효율적인 영상처리를 할 수 있다는 장점을 갖고 있다. 그러나 불량화소의 발생은 곧 화질의 저하로 연결되기 때문에 불량화소를 검출하는 방법에 대한 연구가 필요하다. 본 논문에서는 CMOS image sensor에 사용되는 효율적인 불량화소 검출 알고리듬과 그 하드웨어를 제안하였다. 불량화소를 검출하기 위하여 본 논문에서 제안한 방법은 Scan, Trace, Detection의 단계를 거친다. 시뮬레이션 결과 특정 조건에서는 99.99%의 불량화소 걸출 성공률을 나타냈다. 제안된 알고리듬은 Verilog HDL로 구현되었으며, 0.25 CMOS standard cell library에서 3.2k개의 게이트 수를 갖는다.

• 전력전자학회논문지
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• 제9권3호
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• pp.267-274
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• 2004

본 논문에서는 새로운 온라인 데드타임 전향보상기법을 제안한다. 데드타임 효과(dead-time effect)로 인한 출력 전압 오차를 외란전압으로 간주하고 이를 추정하여 전향보상한다. 외란전압의 크기를 시간지연제어기법을 이용하여 추정하고, 추정된 값과 측정된 전류와 위치 정보로써 외란전압을 계산한다. 데드타임 효과를 보상하기 위해 계산된 외란전압은 전압지령에 전향된다. 제안된 방법은 DSP TMS320C31을 사용하여 디지털방식으로 영구자석 동기 전동기 구동 시스템에 적용이 된다. 제안된 방법의 효용성을 검증하기 위해 이 시스템에서 실험을 수행하였고 그 결과는 제안된 방법의 효과를 잘 보여주고 있다.

• 전력전자학회논문지
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• 제20권2호
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• pp.115-121
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• 2015

Stand-alone inverter supplies constant voltage to loads. However, when a three-phase stand-alone inverter supplies unbalanced load, the generated output voltages also become unbalanced. The nonlinear characteristics of inverter dead time cause a more serious distortion in the output voltage. With unbalanced load, voltage distortion caused by dead time differs from voltage distortion under balanced load. Phase voltages in the stationary reference frame include unbalanced odd harmonics and then, d-q axis voltages in the synchronous reference frame have even harmonics with different magnitude, which are mitigated by the proposed multiple resonant controller. This study analyzes the voltage distortion caused by unbalanced load and dead time, and proposes a novel dead time compensation method. The proposed control method is tested on a 10-kW stand-alone inverter system, and shows that total harmonic distortion (THD) is reduced to 1.5% from 4.3%.

• 전력전자학회논문지
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• 제17권3호
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• pp.213-221
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• 2012

In a PWM inverter-fed IPMSM (Interior Permanent Magnet Synchronous Motor) drive, a dead time is inserted to prevent a breakdown of switching device caused by the short-circuit of DC link. This distorts the inverter output voltage resulting in a current distortion and torque ripple. In addition to the dead time, nonlinearity exists in switching devices of the PWM inverter, which is generally dependent on operating conditions such as the temperature, DC link voltage, and current. The voltage disturbance caused by the dead time and inverter nonlinearity directly influences on the inverter output performance, and it is known to be more severe at low speed. In this paper, a new compensation scheme for the dead time and inverter nonlinearity under the parameter variation is proposed for a PWM inverter-fed IPMSM drive. The overall system is implemented using DSP TMS320F28335 and the validity of the proposed algorithm is verified through the simulation and experiments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 E
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• pp.1715-1717
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• 1997

This paper deals with the dead operation characteristics of the earth leakage circuit breaker(ELB) caused by impulse voltages. The surge protective devices for electronic circuit and AC power lines are becoming more widely used. It is possible to give rise to the malfunction of ELB due to the operation of surge protective devices, and the interruption of AC power lines brings about several disadvantages such as low reliability of electronic and informational systems, economical loss, and etc. The dead operation characteristics of the ELB from impulse voltages were measured under the conditions of KS C 4613 and the test circuit with a varistor. As a result, the peak current value of the zero-phase sequence circuit of the ELB is increased as the surge voltage and stray capacitance increase. All of the ELBs used in this work were satisfied with the lightning impulse dead operation test condition defined in KS C 4613. However one specimen only did not cause dead operation in the condition of the test circuit with a varistor. There is high possibility that a large portion of the ELBs connected with the AC power lines having the surge protective devices bring about the dead operation.

• 전기학회논문지
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• 제66권1호
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• pp.55-60
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• 2017

Capacitor Charging Power Supply(CCPS) is one of the most important components of a pulsed power system. The CCPS is widely used in source of lasers, accelerators and plasma generators. This paper presents design of a dead time control circuit and operation characteristics for stable high repetition rate of high voltage CCPS. The CCPS consists of battery, high voltage transformer and controller with a dead time control circuit. A dead time control circuit was simulated by PSpice. The performance test of the CCPS was carried out with a 7[nF] load capacitor at output voltage of 50[kV] and a pulse repetition frequency of 100[Hz]. As a result, we can verify that charging and discharging waveform is stable at 100[Hz]. The experiment results indicate that 3[ms] dead time made it possible for stable high repetition rate of 100[Hz]. This paper paves the way for designing an advanced CCPS which is more applicable outside experiments.

• Journal of Chest Surgery
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• 제18권4호
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• pp.771-779
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• 1985

It has been recognized that the proper matching of ventilation and perfusion within the lung is essential for the efficient exchange of gases following open heart surgery. Physiologic shunt reflects the amount of blood going to lung units with inadequate ventilation and these are also areas of the lung with adequate ventilation but inadequate blood flow. This can be quantified by measuring physiological dead space. From January to August 1985, The physiologic dead space and shunt during postoperative course had been taken in 30 patients of open heart surgery in Soonchunhyang University Hospital. Twenty cases had congenital heart disease and acquired valvular heart disease were noticed in 10 cases. The physiological dead space and shunt during postoperative periods were calculated and we made 5 items of conclusion: 1. There is high probability of ventilation-perfusion mismatch in the acquired heart disease group compared to the congenital group. 2. Duration of the CPB can exert significant influences in the physiological dead space but less in the shunt fraction. 3. There is positive relationship between Qs/Qt and Vd/Vt in the group B [CPB>90 min.] but less reliable in correlation. 4. Perfusion impairment is more significant in the diminished pulmonic blood flow group compared to the increased pulmonic blood flow [Qp/Qs>2.0] group. 5. There is no significant ventilation-perfusion mismatch within the lung during all postoperative courses.

• 대한간호학회지
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• 제31권1호
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• pp.31-42
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• 2001

This study was done to evaluate the effect reducing artificial dead space on intubated children. Data were collected from July 1st, 1998 to August 31st, 1999. The subjects were selected from a pediatric intensive care unit of 'S' hospital and intubated with 3.5 mm or 4.5 mm endotracheal tube after open heart surgery. They were composed of 34 patients : 17 patients were assigned to the experimental group and the rest of them were placed in the control group. The artificial airway volume was minimized in the experimental group, and the control group maintained the artificial airway volume. ETCO2, PaCO2, SPO2 were measured as indicators of pulmonary ventilation. The tools of this study were GEM-Premier and Space-Lab patient monitors. The data were analyzed using the SPSS/PC+ program. The $\chi$2 -test was used to find general characteristics. The t-test was used to test the homogenety of the pulmonary ventilation status and mechanical ventilation setting before intervention between the two groups. Also, the paired t-test was used to examine the hypothesis. The results can be summerized as : 1. CO2 can be expelled effectively from the body in case artificial dead space was decreased. 2. As the artificial dead space was reduced, the difference between ETCO2 and PaCO2 was decreased, in other words pulmonary ventilation was improved. 3. If the artificial dead space occupied above 15 percent of tidal volume, the effect of CO2 was retention revealed in the body. 4. If the artificial dead space occupied below effect. Based on the results, the following is suggested to be applied practically : 1. A kind of the ventilator circuit acting artificial dead space should be removed from the intubated children with mechanical ventilaion. 2. The endotracheal tube should not be cut because extra-body space of the endotracheal tube did not have an effect on the dead space of the intubated children. Since the researcher could not cover this aspect in the study, they recommend the following. 1. The study should be extended to the other pulmonary disease patients for the effect of improving pulmonary ventilation. 2. Also, further studying with a more narrow interval in the extra-body space of the artificial airway will be able to explain the point of artificial dead space with proper ventilation.

• 유기물자원화
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• 제23권1호
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• pp.70-81
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• 2015

Helicase는 NTP 결합의 화학적 에너지를 이용하여 이중가닥의 DNA와 RNA를 단일가닥으로 분해하여 다양한 생체반응에 기여하는 단백질로 알려져 있으며, 이 중 DEAD-box의 단백질은 주로 RNA와 관련된 대부분의 생화학적 반응에 작용하는 ATP 의존성 helicase로 알려져 있다. 또한 이 단백질 부류에 속하는 DEAD-box3 (DDX3) gene은 척추동물뿐만 아니라 무척추동물에서의 유성 생식과 무성 생식에서 생식세포 발달 및 재생과정 중 줄기세포 분화에 중요한 역할을 하는 인자로 알려져 있다. 이에 본 연구는 강한 재생능력을 가진 것으로 알려져 있는 팔딱이 지렁이(Perionyx excavatus)에서 DDX3 gene을 동정하고 그 발현양상을 알아보고자 환대를 포함하는 성체 지렁이의 두부를 절단하여 total RNA를 추출하고, 이를 주형으로 RT-PCR을 수행하여 full length의 DDX3 gene인 Pe-DDX3를 검출하였다. Pe-DDX3는 607개 아미노산 서열로 이루어져 있으며, DEAD-box 단백질 그룹 내에서 특이적으로 보존되어 있는 9개의 motif가 존재하고 있다. 다른 분류군에 속하는 동물들과의 multiple alignment를 통해 서열 내에 보존되어 있는 아미노산 서열을 확인할 수 있었으며, 아미노산 차원에서의 계통수 분석을 통해 DDX3 (PL10) 하부그룹에 속하는 것을 알 수 있었으며, 또한, 같은 그룹에 속하는 동물 중 P. dumerilii의 PL10a, b 단백질과 가장 가까운 유연관계를 확인 할 수 있었다.

• 대한임상독성학회지
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• 제8권1호
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• pp.16-23
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• 2010

Purpose: Organophosphate insecticide poisoning is common in Korea, but there is no definitive guideline for determining the severity of the poisoning and the predictive factors. Therefore, we evaluated the organophosphate poisoned patients and we divided them into two groups, the survivors and the dead, and the results might be useful for treating organophosphate poisoning patients. Methods: We performed a retrospective analysis of 68 organophosphate poisoned patients who visited the Chosun University Hospital Emergency Medical Center during a 24-month period from January, 2007 to December, 2008. We made a work sheet of the patients' characteristics and the collected data was analyzed and we compared this data between the survivor group and the dead patient group. Results: There were significant differences between the survivor group and the dead patient group for the mean age, the alcohol intake state and the typically expressed signs. The dead patients had lower blood pressure, tachycardia and a lower Glasgo Coma Score (GCS) score than the survivor group. On the arterial blood gas analysis, the dead patients had more severe acidemia and they had lower saturations. Increased serum amylase levels were found in the dead patients. The survivors'initial and follow up serum pseudocholinesterase activity (after 6~8 days) was significantly higher than that of the dead group. The total amount of atropine injected to patient was less in the survivors than that in the dead patients. Conclusion: Old age and expressing the typical intoxication signs, a lower GCS score and blood pressure, showing acidosis on the gas analysis and low serum cholinesterase activity may be useful as poor prognostic indicators for patients with organophosphate poisoning. We suggest that physicians must pay careful attention to the signs and prognostic factors of organophosphate insecticide poisoned patients.