• 제목/요약/키워드: TECHNIQUE

검색결과 60,903건 처리시간 0.063초

A New Random PWM Technique for Conducted-EMI Mitigation on Cuk Converter

  • Krishnakumar, C.;Muhilan, P.;Sathiskumar, M.;Sakthivel, M.
    • Journal of Electrical Engineering and Technology
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    • 제10권3호
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    • pp.916-924
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    • 2015
  • Electromagnetic Interference (EMI) is a system to system or environment to system phenomenon. The literature survey proved that the Randomized Pulse Width Modulation (RPWM) technique is a promising technique to reduce EMI. A new Constant Trailing Edge, Randomized Pulse Width Modulation (CTERPWM) technique is proposed in this paper. The effect of the proposed RPWM technique for mitigation of conducted-EMI on Cuk converter operating in Continuous Conduction Mode (CCM) is simulated and tested. In this paper, the analytical expressions for the Power Spectral Density (PSD) are derived for the proposed RPWM technique and are validated by experimental measurements. The effectiveness of the proposed RPWM technique on the mitigation of conducted-EMI is verified comparing simulation and experimental results and it is identified that both the results are almost similar with allowable experimental deviations. The comparative investigation proves that the proposed RPWM technique can mitigate and spread the dominant peaks of conducted-EMI over the complete spectrum for the Cuk converter. Based on the investigation the CTERPWM technique is recommended for adoption.

An Iterative Technique for Real-Time Tracking of Power System Harmonics

  • Sidhu, T.S.;Zadeh, M.R.D.;Pooranalingam, P.J.;Oh, Yong-Taek
    • Journal of Electrical Engineering and Technology
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    • 제6권3호
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    • pp.319-327
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    • 2011
  • An iterative technique based on orthogonal filters and frequency tracking is proposed to estimate harmonic components in power systems. The technique uses frequency interpolation to estimate fundamental frequency and harmonics when the nominal frequency of the signal is a non-integer value. Due to the number of computations involved during the generation of filter coefficients, an offline computation is suggested. Beneficial features of the proposed technique include fixed sampling rate and fixed data window size. The performance of the proposed technique is examined by simulating different power system operating conditions and evaluating the data from these simulations. A technique based on Fast Fourier Transform is also used to estimate the harmonic components for all the simulated signals. These estimates are compared with those obtained from the proposed technique. Results show that the proposed technique can converge to the accurate fundamental frequency and therefore, provide accurate harmonic components even when the fundamental frequency is not equal to the nominal frequency.

디지털 유방확대촬영술에서 Air gap technique의 유용성 평가 (Evaluation of the Usefulness for Air Gap Technique in Digital Magnification Mammography)

  • 김미영
    • 대한방사선기술학회지:방사선기술과학
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    • 제37권2호
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    • pp.101-107
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    • 2014
  • 이 연구는 디지털 유방확대촬영술에서 방사선 피폭을 감소시키며 영상의 질을 유지하기 위한 최적의 촬영조건을 알아보았다. 자동노출방식의 평균유선선량이 수동노출방식에 비해 높은 것으로 나타났다. 자동노출방식은 그리드(grid) 사용 여부에 따라 평균유선선량과 화질평가에 차이가 많았으나, 수동노출방식은 팬텀영상평가 점수에서만 차이가 있었다. 그러나 air gap technique을 사용할 경우 모든 노출방식에서 신호대잡음비의 증가가 뚜렷하게 나타났다. 따라서 유방확대촬영 시 air gap technique을 사용한다면 환자의 평균유선선량을 감소시키고 신호대잡음비를 높여 양질의 화질을 유지할 수 있을 것이다.

"동의보감(東醫寶鑑)"에 기재된 위법(熨法)의 활용에 대한 조사 (The Study for Application of the Hot Medicinal Compress Technique of the Donguibogam)

  • 권오상;백승민;김슬기;최선미
    • Korean Journal of Acupuncture
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    • 제28권4호
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    • pp.137-145
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    • 2011
  • Objectives : This research dealt with the content of the hot medicinal compress technique in Donguibogam in order to develope the hot medicinal compress technique as a new therapy technique. Methods : In this research, we searched for the hot medicinal compress treatment in Donguibogam. Results : The hot medicinal compress technique mainly cures the diseases on the body surface and it can be applied to digestive troubles and gynecologic diseases. The hot medicinal compress technique is operated mainly at wound around the affected parts and it is applied to the constitutional symptom at the abdominal region. In the hot medicinal compress technique was used much more with medication, and the herbs used in the treatment consists of hot tastes and the warm characteristics. In the hot medicinal compress method with direct heating the herbs was mainly used. Conclusions : The hot medicinal compress technique is considered as treatment which can be utilized easily and it can be used an easy and useful self-treatment.

전진 속도를 가지는 부유체 운동 문제에 대한 방사기법 비교 연구 (Comparative Study on the Radiation Techniques for the Problem of Floating Body Motion with Forward Speed)

  • 오승훈
    • 대한조선학회논문집
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    • 제56권5호
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    • pp.396-409
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    • 2019
  • In this paper, a comparative study on the radiation techniques for the motion analysis of the three dimensional floating structure with the forward speed was carried out. The Sommerfeld radiation condition, the damping technique, and the point shift technique were used for the comparative study. Radiated wave patterns and hydrodynamic coefficients of the heave motion of floating structure with the forward speed were compared and analyzed. The characteristics and limitations of each radiation technique were analyzed through the calculation results. To overcome the limitations of conventional radiation techniques, the hybrid radiation technique combining the Sommerfeld radiation condition with the damping technique was proposed. It is confirmed that the proposed method, the Hybrid radiation technique, improves the limitation of the speed range and the dissipation of the wave of the conventional radiation technique. The motion analysis code of the three dimensional floating structure with the forward speed based on the Rankine source method with hybrid radiation technique was developed. In order to validate the developed code, hydrodynamic analyses were carried and compared with published experiments.

McSpadden Technique의 근관폐쇄효과에 대한 실험적 연구 (A STUDY ON THE SEALING ABILITY OF McSpadden TECHNIQUE)

  • 이상탁;이정식
    • Restorative Dentistry and Endodontics
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    • 제10권1호
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    • pp.127-134
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    • 1984
  • This study was conducted to evaluate the sealing ability of McSpadden technique compared with lateral condensation and Engine reamer technique, and according to the degree of canal enlargement and the use and nonuse of sealer. Seventy single-rooted teeth were divided into 14 groups and each tooth was enlarged and obturated according to the purpose of this study. Obturated teeth were infiltrated by Indian ink and decalcified and cleared. The apical sealing ability was evaluated by measuring the degree of ink penetration into the canal. The results were as follows: 1. All the teeth filled by lateral condensation using gutta-percha cone and sealer proved better in canal sealing ability than McSpadden technique and Engine reamer technique, showing less ink penetration. 2. In the McSpadden technique, there was less ink penetration detected in using the sealer than not. 3. In all of the experimental methods, the difference of the degree of ink penetration according the degree of canal enlargement could not be accepted. 4. There was no significant difference in ink penetration degree between Engine reamer technique using sealer and McSpadden technique without sealer.

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도재전장주조관의 제작방법에 따른 순측 치경부 변연 적합도에 관한 주사전자현미경적 연구 (A SCANNING ELECTRON MICROSCOPIC STUDY ON THE LABIAL MARGINAL FIT OF METAL CERAMIC CROWNS MADE BY DIFFERENT TECHNIQUES)

  • 윤일중;장완식;양재호;이선형
    • 대한치과보철학회지
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    • 제24권1호
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    • pp.151-164
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    • 1986
  • The purpose of this study was to evaluate the marginal fit of metal ceramic crowns made by different techniques. The techniques were metal butt margin technique, platinum foil technique, shoulder powder techniques and wax technique. The latter three techniques were for the fabrication of collarless metal ceramic crowns. Ten crowns were made of each techniques, and marginal fit was evaluated using scanning electron microscope under X200 magnification. The results were as follows. 1. The marginal fit in the descending order were wax technique shoulder powder technique, platinum foil technique and metal butt margin, before cementation, and wax technique, shoulder powder technique, metal butt margin, and platinum foil technique, after cementation. 2. The fit of collarless metal ceramic crowns was comparable to metal ceramic crowns with metal butt margins. 3. There were no statistically significant differences between marginal fit of metal ceramic crowns made by different techniques.

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국내 응급실에서의 골수강내 주입법 사용 현황 (Current Status of Intraosseous Infusion Technique Use at Emergency Departments in Korea)

  • 최상천;박현수;김재우
    • Journal of Trauma and Injury
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    • 제20권1호
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    • pp.6-11
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    • 2007
  • Purpose: Gaining vascular access is difficult and time-consuming in critically ill children, so nowdays, in many countries, intraosseous vascular access is frequently used for rapid vascular access in critically ill children. Its pharmacokinetics is close to that of the peripheral intravenous route, but its infusion flow rate is faster. The purpose of this study was to determine how widely the intraosseous infusion technique was being used in Korean emergency departments. Methods: We telephoned forty-two (42) randomly selected university-affiliated hospitals. We asked physicians if they use the intraosseous infusion technique. Responders were emergency and pediatric residents and emergency faculty. If they responded that they were not using the intraosseous infusion technique, we asked the reason. Also, we asked about their experiences with the intraosseous infusion technique. Results: Forty-two (42) hospitals were enrolled in this study. No hospital used the intraosseous infusion technique on a regular basis. However, 8 hospitals used the intraosseous infusion technique occasionally. None of the responders had experience with the intraosseous infusion technique. Conclusion: The intraosseous infusion technique is currently underrepresented at emergency departments in Korea.

Enhancing Venous Anastomosis Visualization in Murine Kidney Transplants: The Two Stay Suture Technique

  • Jong-Min Kim
    • 한국임상수의학회지
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    • 제40권6호
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    • pp.423-428
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    • 2023
  • The mouse kidney transplantation model serves as an invaluable tool for exploring various aspects of the transplant process, including acute rejection, cellular and humoral rejection, ischemia-reperfusion injury, and the evaluation of novel therapeutic strategies. However, conducting venous anastomosis in this model poses a significant challenge due to the thin and pliable characteristics of the renal vein, which often obstruct clear visualization of the resected vein's edge. This study proposes the adoption of a two stay suture technique to enhance the visualization of the renal vein's edge, thereby facilitating efficient and successful venous anastomosis. A total of 22 mice served as kidney donors in this study. The conventional anchoring suture technique was employed for venous anastomosis in 11 of these mice, while the remaining 11 underwent the two stay suture technique. The anastomosis duration and completion rates were then compared between these two groups. The conventional anchoring suture technique yielded an average anastomosis time of 29 minutes and a completion rate of 64%. In contrast, the two stay suture technique demonstrated a substantial improvement, with an average anastomosis time of 14 minutes and a completion rate of 100%. The two stay suture technique offers a promising solution to enhance visualization during venous anastomosis in murine kidney transplantation. This technique may particularly benefit novices by enabling them to perform venous anastomosis more easily, swiftly, and successfully.

Bentall수술에서 inclusion technique 과 open technique의 비교 (Comparision of Inclusion TechnicRue with Open Technique in Patients with Bentall Procedures)

  • 김정택;문준호
    • Journal of Chest Surgery
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    • 제30권5호
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    • pp.506-511
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    • 1997
  • 1980년 10월부터 1995년 5월까지 대동맥근 치환을 받은 53명의 환자를 대상으로 inclusion technique(IT)과 open technique(OT)의 수술성적을 비교하였다 대동맥근 치환술의 원인으로 W군에서는 대동맥륜확장을 동반할 상3n대동맥 동맥류가 20례, 대동맥박리가 8례, 그리고 인공판막심내막염이 1례였다. 07군에서는 대동맥륜 가성동맥류가 1례 있었다. 수술방법으로 Bentall등이 기술한 방 확장이 9례, 대동맥박리가 14례, 상행대동맥 법 또: 약가 변형된 방법을 사용하였다. 수술사망은 W군에서 패혈증과 심실부정 맥으로 각각 1례가 사망하 o3고 07구에서는 출혈로 1례가 사망하였다. 만기합병증은 W군에서 8례 발생하였으며 Of군에서 2례 발생하다. 마기사망은 W군에서 7례,07군에서 1례 발생하였다. 12개월 event free는 W군과 07군에서 각각 87% 와 85%, 24개월 생존률은 각각 87% 와 95%로 W군이 24개월생존률이 약간 높았으나 두 군 간에 통계학적 이 유의성은 없었다. nan으로 대동맥륜확장을 동반한 상행대동맥류나 대동맥박리에서 composite valve를 이용한 대동맥근 치 화술으 마조할 만한 단기 수술결과를 보여주었으나 inclusionfwrap technique과 ope technique간에 통계학적으로 의미있는 차이는 발견할 수 없었다. 그러나 시간이 지남에 따라 prothesis와 관련된 만기 합병증의 빈도가 증가하기 때문에 수술 후 추적관찰에 대한 노력이 장기생존에 중요할 것으로 생각된다.

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