• 한국표면공학회지
• /
• 제45권2호
• /
• pp.53-60
• /
• 2012

Modulated Pulse Power (MPP) magnetron sputtering is a new high-power pulsed magnetron sputtering (HPPMS) technology which overcomes the low deposition rate problem by modulating the pulse voltage shape, amplitude, and the duration. Highly ionized magnetron sputtering can be performed without arcing because it can be controlled as multiple steps of micro pulses within one overall pulse period in the range of 500-3,000 ${\mu}s$. In this study, the various waveforms of discharge voltage and current for micro pulse sets of MPP were investigated to find the possibility of controlling the strongly ionized plasma mode. Enhanced ionization of the sputtered metal atoms was obtained by OES. Large grained columnar structure can be grown by the strongly ionized plasma mode in the AZO deposition using MPP. In the most highly ionized deposition condition, the preferred orientation of (002) plane decreased, and the resistivity, therefore, increased by the plasma damage.

• 전기학회논문지
• /
• 제56권8호
• /
• pp.1445-1449
• /
• 2007

This paper presents the DOD (Drop-On-Demand) characteristic using the electrostatic field induced inkjet printing system. In order to achieve the DOD characteristic of electrostatic field induced inkjet printing, applied the bias voltage of 1.4 kV and the pulse voltage of $2.0\;kV\;{\sim}\;2.7\;kV$ using high voltage pulse generator. Electrostatic field induced droplet ejection is directly observed using a high-speed camera and for investigated DOD characteristic, CNT ink used. The electrostatic field induced inkjet head system has DOD characteristic using pulse generator which can be applied pulse voltage. The bias voltage has a good condition which form meniscus and has micro dripping mode for small size micro droplet. Also, the droplet size decreases with increasing the applied pulse voltage. This paper shows DOD characteristic at electrostatic field induced inkjet head system, Therefore. electrostatic DOD inkjet head system will be applied industrial area comparing conventional electrostatic inkjet head system.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제15권4호
• /
• pp.493-500
• /
• 2015

A flyback converter operates with either pulse width modulation (PWM) or pulse frequency modulation (PFM) control scheme depending on the load current. At light load condition, PFM control is employed to reduce the switching frequency and thereby minimize the switching power loss. For heavier load, PWM control is used to regulate the output voltage of the flyback converter. The flyback controller has been implemented in a $0.35{\mu}m$ BCDMOS process and applied to a 40-W flyback converter. The light-load power efficiency of the flyback converter is improved up to 5.7-% comparing with the one operating with a fixed switching frequency.

• 대한전자공학회논문지
• /
• 제8권4호
• /
• pp.7-16
• /
• 1971

쌍트란지스터 회로에 의하면 전류제어형의 부성저항소자가 가능하다. 이와같은 부성소자를 사용한 구형파발진회로의 바이어스전류에 신호파를 중첩함으로써 펄스폭변조회로를 구성하였다. 신호파가 정인 경우에는 한쪽의 트란지스터의 바이어스전류만을 증가시키고, 또 신호파가 부인 경우에는 다른 한쪽의 바이러스만을 증가시키는 방법을 채택하였다. 따라서 신호회로로서 일종의 전파정류회로의 변형을 채용하였다. 발진주기의 이론적해석과 회로정수결정의 설계지침을 구명하고 실험회로를 제시하였다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
• /
• pp.544-544
• /
• 2000

From ancient times. the diagnosis method of the oriental medicine has been Performed by curing diseases by means of rectifying and adjusting the unbalance in the Physiological function of the five viscera and the six bowels of a human body. Diseases have been diagnosed by the condition of blood circulation that cycles a human body through blood vessels by dint of the vitality of the heart, Based on such a systematic pulse diagnosis method, the article presents parameters that will be beneficial to clinical application on the basis of its analysis of the filtering for eliminating noises from pulse signals inputted from sensor group the digital hardware dealing with signals necessary for recognition algorithm. and the structure of diagnosis algorithm and components of pulse waveform.

• 설비공학논문집
• /
• 제4권1호
• /
• pp.20-32
• /
• 1992

A numerical solution for heat transfer in the flue tube of a pulse combustion water heater was presented. The $k-{\varepsilon}$ turbulent model was adopted to describe turbulent characteristics and radiative heat transfer was calculated by P-N approximation. Three pulsating conditions equivalent to existing experimental studies were used for analysis. Pulsating pressure was specified at the inlet and outlet of flue tube and numerical procedure using control volume method and pressure boundary condition was presented. It was found that the present mathematical model and numerical method could predict effectively the flow field and heat transfer for the flue tube in pulse combustor.

• Journal of Microbiology
• /
• 제35권3호
• /
• pp.181-187
• /
• 1997

Filamentous cyanobacteria are an ecologically important group of bacteria because they are able to provide both organic carbon fixed nitrogen that can support the nutritional requirements for other microorganisms. Because of their prokaryotic nature, they can also be used as potentially powerful model systems for the analysis of oxygenic photosynthesis and nitrogen fixation. Gene transfer is an indispensable procedure for genetic analysis of filamentous cyanobacteria. Electroporation was used to introduce foreign DNA into cyanobacterial cells. In experiments designed to optimize the electroporation technique, the effects of the field strength (amplitude of pulse) and time constant (duration of pulse), DNA concentration and host restriction/modification of DNA on the efficiency of electro-transformation were investigated. The results of this research revelaed that a high voltage pulse of short duration was effective for the electro-transformation of Anabaene sp. M131. The maximal number of transformants was obtained at 6 kV/cm with a pulse duration of 5 msec. The efficiency of electro-transformation was also sensitive to concenetration of DNA; even small amounts of DNA (0.01 .mu.g/ml) were able to gie a large number of transformants (1.0 * 10$\^$3/ cfu/ml).

• 한국정밀공학회지
• /
• 제22권5호
• /
• pp.37-44
• /
• 2005

In this paper, wire electrochemical machining (Wire ECM) with ultra short pulses is presented. Platinum wire with $10{\mu}m$ diameter was used as a tool and 304 stainless steel was locally dissolved by electrochemical machining in 0.1M $H_{2}SO_4$ electrolyte. Wire ECM can be easily applied to the fabrication of arbitrarily shaped micro-grooves without tool wear. The change of machining gap according to applied pulse voltage, pulse on-time and pulse period was investigated and the optimal pulse condition for stable machining was obtained. Using this method, various micro-grooves with less than $20{\mu}m$ width were fabricated.

• 한국초전도ㆍ저온공학회논문지
• /
• 제14권4호
• /
• pp.50-53
• /
• 2012

This paper describes experimental study on GM-type pulse tube refrigerator (PTR). In a PTR, the pulse tube is only filled with working gas and there exists secondary flow due to a large temperature difference between cold-end and warm-end. The stability of secondary flow is affected by orientation of cold-head and thus, the cooling performance is deteriorated by gas mixing due to secondary flow. In this study, a single stage GM-type pulse tube refrigerator is fabricated and tested. The cooing performance of the fabricated PTR is measured as varying cold-head orientation angle and the results are used as reference data. Then, we divided interior space of pulse tube into three segments, and fixed the various size of screen mesh at interface of each segment to suppress the performance degradation due to secondary flow. For various configuration of pulse tube, no-load test and heat load test are carried out with the fixed experimental condition of charging pressure, operating frequency and orifice valve turns. From experimental results, the fine screen mesh shows the effective suppression of performance degradation for the large orientation angle, but the use of screen mesh cause the loss of cooling capacity rather than the case of no insertion into pulse tube. It should be compromised whether the use of screen mesh in consideration of the installation limitation of a GM-type pulse tube refrigerator.

• 대한한의진단학회지
• /
• 제9권2호
• /
• pp.10-24
• /
• 2005

Background and Purpose: Feeling the pulse is based on the pulse condition and alteration to observe the condition of the human body's health and by using a healthy person's pulse as a standard we are able to analyze the patient's pulse to find the attacked channel and collateral, viscera and bowels and understand the pathology such as diseases caused by exogenous evil, disorder of internal organs, and seven modes of emotions. Observing the color and shade of the patient's face, listening carefully to the sound of the patient, and feeling the pulse are methods in accordance with Su Wen 'Plain Questions', 'The Classic on Difficulty' (5th century B.C. Bianque), 'The Classic of Sphymology' (280 A.D. Wang Xi), 'Pulse Formulas' (1189 A.D. Cui Jiayan), and is systematically edited for those who have started studying to easily reach the profound state. Therefore, 'The Elementary Course for Medicine' has been used from ancient times as the textbook for diagnostics. Methods: In this Study, we will inspect commonly used pulse feeling methods, the inch, bar, cubit thesis, the viscera and bowels thesis from The Elementary Course for Medicine and inquire the difference of the text from 'Plain Questions of Huangdi's Internal Classic', 'Treatise on Febrile Diseases', 'Classic on Difficulty'. Results and Conclusion: 1. In 'The Elementary Course for Medicine' the site of the wrist along the pulsation of the radial artery is divided into inch, bar, cubit and has defined the inch, bar, cubit crossways. 2. In 'The Elementary Course of Medicine' the inch, bar, cubit for the left hand and right hand is subjected to each viscera and bowel. By assigning the left hand's inch, bar, cubit to the cardial orb, the hepatic orb, the renal orb, and the right hand's inch, bar, cubit to the pulmonic orb, the splenic orb, the vital gate it has been able to feel the pulse for each viscera and bowel by using the interpromoting and interacting relation of the five evolutive phases.