• BMB Reports
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• 제50권10호
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• pp.496-503
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• 2017

The human body loses several billions of cells daily. When cells die in vivo, the corpse of each dead cell is immediately cleared. Specifically, dead cells are efficiently recognized and cleared by multiple types of neighboring phagocytes. Early research on cell death focused more on molecular mechanisms of cell death regulation while the cellular corpses were merely considered cellular debris. However, it has come to light that various biological stimuli following cell death are important for immune regulation. Clearance of normal dead cells occurs silently in immune tolerance. Exogenous or mutated antigens of malignant or infected cells can initiate adaptive immunity, thereby inducing immunogenicity by adjuvant signals. Several pathogens and cancer cells have strategies to limit the adjuvant signals and escape immune surveillance. In this review, we present an overview of the mechanisms of dead cell clearance and its immune regulations.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 춘계학술대회 논문집
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• pp.241-245
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• 1995

This paper shows that the proposed fuzzy-sliding mode for SCARA robot control could reduce chattering problemed in sliding mode control and is robust against parameter uncertainties. It was very small quantities of chattering in the fuzzy-sliding mode control conpared with that in sliding mode control with two dead-band. In here, the sliding mode control with two dead-band is the method to reduce some chattering by changing into a continuous variable lower control input gain when a state value in pahase palne converged sithin two dead-band. But, the fuzzy-sliding mode control for more reducing chattering is the method to change control input by slicing mode into that by fuzzy rule within two dead-band. Simulations show that the effect of reducing chattering by the fuzzy-sliding mode is superior to sliding mode control with two dead-band.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.265-269
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• 1994

The switching dead time avoiding a bridge leg short circuit in PWM voltage source inverter produces distortions of the controlling inverter output performance such as current waveform, voltage vector, and torque. In this paper, the influence of dead time is investigated. The on-line space voltage vector modulation method is used for current controller. It is possible to compensate dead time by space voltage vector modulation which generates additional pulse compensating voltage distortion caused by dead time. In addition, narrow pulse which is generally neglected can be compensated. All the algorithms, including field-oriented control are performed by one chip microprocessor 80C196MC and DSP TMS320C31. Experimental results probe that the proposed scheme provides a good inverter output performance.

• 대한전기학회논문지
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• 제39권3호
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• pp.273-280
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• 1990

To prevent the shoot-through phenomena in a PWM inverter, a short dead time is usually provided between a pair of switching transistors in the same leg of the inverter. In this approach, the amount of the dead time is designed to meet the worst case condition of the inverter transistors and the base drive elements. So, in normal cases, relatively large portion of the dead time is unnecessary and it results in an undesirablecurrent waveform distortion and generates ripple torque on the motor shaft. In this paper, a new base drive method to remove the undesirable portion of the dead time is described. The method senses the transistor on/off states to interlock the other transistor of the leg without the external dead time. Also, for the transistors of large current rating, the Darlington drive circuit is combined to the proposed method and is tested to verify the effectiveness. The experimental results of the proposed method are described and compared with those of the conventional dead time method.

• 영어영문학
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• 제55권3호
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• pp.429-440
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• 2009

This paper does not follow the well-known critical practice of Charles Perke, Edward Brandabur and Phillip Herring who, regarding The Dead, James Joyce s earliest masterpiece, as the conclusion of Dubliners, classify Gabriel as one of the dead. Instead it concurs with such critics as William York Tindal, Kenneth Burke and Allen Tate who, interpreting The Dead as a story of Gabriel s spiritual maturation, discuss the famous snow vision at the end of the story as a signifier of his rebirth experience. A new reading of The Dead, which is the aim of this paper, examines the very processes which produce both form and content, thereby demonstrating that The Dead is a story of Gabriel s spiritual growth and that the supreme snow vision is prepared for his spirit which progresses towards a richer synthesis of life and death, a higher altitude of flight and wider horizons.

• 한국패류학회지
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• 제28권3호
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• pp.187-196
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• 2012

폐쇄 사육 시스템에서 고착성 무척추동물 특히 연체동물의 부착용 재료로서 이용되고 있는 dead rock과 live rock이 수질에 부가적으로 미치는 영향을 파악하고자 인도네시아로부터 수입된 dead rock과 live rock을 인공해수를 이용한 실험수조에 투입 한 후 수질변화를 관찰하였다. 두 종류의 rock들은 모두 pH 안정에 영향을 주었으며 질소화합물의 분해에도 일정한 영향을 주는 것으로 나타났다. dead rock의 경우 사용전 충분한 안정화 기간을 거침으로써 부착용 도구로서 뿐만 아니라 훌륭한 보조여과 기능을 담당할 수 있는 것으로 사료된다. live rock의 경우에는 이미 부착되어 서식하고 있는 조류나 박테리아에 의해 dead rock에 비해 더욱 높은 질소화합물 분해 능력을 나타냈으며 초기 투입 시 부착되어 있는 생물의 폐사나 해적생물의 유입에 따른 위험성을 제거 할 경우 사육시스템 내에서 단순한 부착용 재료로서 뿐만 아니라 다양한 목적에 이용가능 할 것으로 사료된다.

• 전기전자학회논문지
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• 제16권3호
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• pp.203-210
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• 2012

기존의 DC-DC 부스트 변환기에 사용되는 non-overlapping gate driver는 dead-time이 고정되어 있기 때문에 body-diode conduction loss 또는 charge-sharing loss가 발생하는 문제점을 가지고 있다. 이러한 loss에 의한 효율 감소를 줄이기 위해 본 논문에서는 dead-time 적응제어 기능을 갖는 PWM DC-DC 부스트 변환기를 설계하였다. 제안된 DC-DC 부스트 변환기는 CMOS $0.35{\mu}m$ 공정으로 설계되었고, 입력전압 2.5V를 받아서 3.3V의 출력전압으로 승압시킨다. 스위칭 주파수는 500kHz이며, 최대효율은 97.3%이다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 추계학술대회
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• pp.71-72
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• 2011

This paper presents a novel and direct dead time compensation method of the 3 phase inverter using space vector pulse width modulation(SVPWM) topology. In the turn on time calculation of the effective voltage, the dead time effect is directly compensated according to the current direction of the midium voltage reference. Since the turn on time of the effective voltage vector is affected by the dead time, the loss time is compensated to turn on time of the effective voltage vector. And the dead time is added to the calculated voltage vector switching times according to the current direction. For the more effective compensation, the direction of the midium phase current is considered by the practical direction and voltage drops in the power devices. The proposed method can compensate the dead time which is considered feedback error or direction of middle phase current without coordinate transform in added controller. The proposed dead time compensation scheme is verified by the computer simulation and experiments of 3 phase R L load.

• 대한임상검사과학회지
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• 제45권4호
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• pp.154-158
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• 2013

The unnatural dead body refers to a corpse which is suspicious of unusual death and the dead case has been occurred more than 20 thousands times every year during the recent five years and most of them are found decayed. Police Scientific Investigators investigate unnatural dead bodies and its surroundings in all-around way and determine whether the death is involved with a crime, and most of the Scientific Investigators are exposed to a danger to get infected with pathogenic bacteria which are generated during the decaying process of dead body and are mostly to cause serious injuries on human beings. In line with the fact, the present study conducted a bacterial analysis by collecting excretions from 60 dead bodies and culturing the bacteria to evaluate infection risk of the police agents. The study cultured bacteria from 60 bodies and classified pathogenic bacteria of 108 strains, and its main bacteria are found to be them (; Acinetobacter baumannii 20 strains (19%), Pseudomonas aeruginosa 19 strains (18%), E. coli 18 strains (17%), Klebsiella pneumoniae 11 strains (10%), Proteus mirabillis 10 strains (9%), Enterococcus faecium 10 strains (9%), Staphylococcus aureus 9 strains (8%), Bacillus spp. 5 strains (5%), Streptococcus pneumoniae 3 strains (3%), Candida albicans 2 strains (2%), Mycobacterium tuberculosis 1 strains (1%)). The study results are expected to be used as educational data for preventing the Police Scientific Investigator from infections with bacteria or as a minimum data for improving work environment of the agents.

• Journal of Power Electronics
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• 제14권2호
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• pp.249-256
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• 2014

A novel topology generation method for the no dead-time three-phase AC/DC converter is proposed in this study. With this method, a series of no dead time topologies are generated and their operation principles are analyzed. The classic three-phase bridge AC/DC converter can realize a bidirectional operation. However, dead-time should be inserted in the driving signals to avoid the shoot-through problem, which would cause additional harmonics. Compared with the bridge topology, the proposed topologies lack the shoot-through problem. Thus, dead time can be avoided. All of the no dead time three-phase AC/DC converters can realize bidirectional operation. The operating principles of the converters are analyzed in detail, and the corresponding control strategies are discussed. Comparisons of waveform distortion and efficiency among the converters are provided. Finally, 9 KW DSP-based principle prototypes are established and tested. Simulation and experimental results verify the theoretical analysis.