• 제목/요약/키워드: PDE

검색결과 323건 처리시간 0.027초

Application of Dry Elixir System to Oriental Traditional Medicine: Taste Making of Peonjahwan by Coated Dry Elixir

  • Choi, Han-Gon;Kim, Chong-Kook
    • Archives of Pharmacal Research
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    • 제23권1호
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    • pp.66-71
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    • 2000
  • Peonjahwan, an oriental traditional medicine composed of crude herbal drugs and animal tissues is bitter and poorly water-soluble. To mask the bitterness of peonjahwan and enhance the release of bilirubin, one of the crude active ingredients of peonjahwan, peonja dry elixir (PDE), was prepared using a spray-dryer after extracting the crude materials in ethanol-water solution. coated peonja dry elixir (CPDE) was then prepared by coating the PDE with Eudragit acrylic resin. Panel assessed bitterness and release test of bilirubin from PDE and CPDE were carried out and compared with peonjahwan alone. PDE was found to have little effect upon the reduction of the bitterness of peonjahwan. However, the bitterness of CPDE was found to reduce to 1/4 of that of peonjahwan due to the encapsulation of crude active ingredients by the dextrin and Eudragit shell (P<0.05). The release rate of bilirubin from PDE and CPDE for 60 min increased about 3.5- and 2.5-fold, respectively, compared to peonjahwan at pH 1.2. It is concluded that CPDE, which masked the bitterness of peonjahwan and enhanced the release of bilirubin, is a preferable delivery system for peonjahwan.

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초기 매칭 에러를 통한 적응적 고속 움직임 예측 알고리즘 (An Adaptive and Fast Motion Estimation Algorithm using Initial Matching Errors)

  • 정태일
    • 한국멀티미디어학회논문지
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    • 제10권11호
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    • pp.1439-1445
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    • 2007
  • 본 논문에서는 기존의 PDE방법의 계산량을 줄이고 동시에 동일한 예측화질을 얻기 위해, 초기 매칭블록의 서브블록별 SAD값의 비교를 통한 고속 움직임 예측 알고리즘을 제안한다. 제안한 방법은 최초 매칭 블록의 서브블록별 매칭 에러의 복잡도의 비교를 통해 후보블록들의 매칭순서를 변경하여 불필요한 계산량을 줄이는 방법을 제안한다. 제안한 알고리즘은 예측 화질의 저하 없이 기존의 PDE(partial distortion elimination) 알고리즘을 이용한 전영역 탐색 방법에 비해 45%의 계산량을 줄였으며, MPEG-2 및 MPEG-4 AVC를 이용하는 비디오 압축 응용분야에 유용하게 사용될 수 있을 것이다.

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THE METHOD OF NONFLAT TIME EVOLUTION (MONTE) IN PDE-BASED IMAGE RESTORATION

  • Cha, Youngjoon;Kim, Seongjai
    • 한국통신학회논문지
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    • 제37A권11호
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    • pp.961-971
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    • 2012
  • This article is concerned with effective numerical techniques for partial differential equation (PDE)-based image restoration. Numerical realizations of most PDE-based denoising models show a common drawback: loss of fine structures. In order to overcome the drawback, the article introduces a new time-stepping procedure, called the method of nonflat time evolution (MONTE), in which the timestep size is determined based on local image characteristics such as the curvature or the diffusion magnitude. The MONTE provides PDE-based restoration models with an effective mechanism for the equalization of the net diffusion over a wide range of image frequency components. It can be easily applied to diverse evolutionary PDE-based restoration models and their spatial and temporal discretizations. It has been numerically verified that the MONTE results in a significant reduction in numerical dissipation and preserves fine structures such as edges and textures satisfactorily, while it removes the noise with an improved efficiency. Various numerical results are shown to confirm the claim.

적외선 열화상 메카니즘과 Flex-PDE 열해석을 통한 STS 결함구조물 진단 (STS Defect Structure Diagonis through the Infrared Thermography Mechanism and Flex-PDE Thermal Analysis)

  • 박영훈;양성모
    • 한국자동차공학회논문집
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    • 제22권4호
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    • pp.20-29
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    • 2014
  • This research aims to study the new paradigm of NDE measurement which allows the identification of defect locations and sizes of a certain structure by measuring its surface temperature after applying heat. STS which has a certain defect is applied by the heat of 70000W by a heater. Its difference of STS surface temperature is measured by using Infrared thermography. The estimated result of STS experiment and that of theoretical analysis of Flex-PDE are compared and analyzed to diagnose STS defect. Moreover, this study can save time and money and improve accuracy in contrast to the existing ultrasonic NDE experiment. In addition, the new paradigm of NDT/NDE by reverse-engineering will be valid if the data of thermal analysis and temperature distribution from the specifications of many materials is accumulated and verified.

Poly(dimethylsiloxane) Mini-disk Extraction

  • Cha, Eun-Ju;Lee, Dong-Sun
    • Bulletin of the Korean Chemical Society
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    • 제32권10호
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    • pp.3603-3609
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    • 2011
  • A novel sampling method of the headspace poly(dimethylsiloxane) (PDMS) mini-disk extraction (HS-PDE) was developed, optimized, validated and applied for the GC/MS analysis of spices flavors. A prototype PDMS mini-disk (8 mm outer diameter, 0.157 mm thickness, 9.4 mg weight) has been designed and fabricated as a sorption device. The technique uses a small PDMS mini-disk and very small volume of organic solvent and less sample size than the solvent extraction. This new HS-PDE method is very simple to use, inexpensive, rapid, requires less labor. Linearities of calibration curves for ${\alpha}$-pinene, ${\beta}$-pinene, limonene and ${\gamma}$-terpinene by HS-PDE combined with GC/MS were excellent having $r^2$ values greater than 0.99 at the dynamic range of 6.06~3500 ng/mL. The limit of detection (LOD) and the limit of quantitation (LOQ) showed very low values. This method exhibited good precision and accuracy. The overall extraction efficiency of this method was evaluated by using partition coefficients ($K_p$) and concentration factors (CF) for several characteristic components from nutmeg and mace. Partition coefficients were in the range from $2.04{\times}10^4$ to $4.42{\times}10^5$, while CF values were 0.88-15.03. HS-PDE was applied successfully for the analysis of flavors compositions from nutmeg, mace and cumin. The HS-PDE method is a very promising sampling technique for the characterization of volatile flavors.

SOLVABILITY OF OVERDETERMINED PDE SYSTEMS THAT ADMIT A COMPLETE PROLONGATION AND SOME LOCAL PROBLEMS IN CR GEOMETRY

  • Han, Chong-Kyu
    • 대한수학회지
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    • 제40권4호
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    • pp.695-708
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    • 2003
  • We study the existence of solutions for overdetermined PDE systems that admit prolongation to a complete system. We reduce the problem to a Pfaffian system on a submanifold of the jet space of unknown functions and then express the integrability conditions in terms of the coefficients of the original system. As possible applications we present some local problems in CR geometry: determining the CR embeddibility into spheres and the existence of infinitesimal CR automorphisms.

Equalized Net Diffusion (END) for the Preservation of Fine Structures in PDE-based Image Restoration

  • Cha, Youngjoon;Kim, Seongjai
    • 한국통신학회논문지
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    • 제38A권12호
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    • pp.998-1012
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    • 2013
  • The article is concerned with a mathematical modeling which can improve performances of PDE-based restoration models. Most PDE-based restoration models tend to lose fine structures due to certain degrees of nonphysical dissipation. Sources of such an undesirable dissipation are analyzed for total variation-based restoration models. Based on the analysis, the so-called equalized net diffusion (END) modeling is suggested in order for PDE-based restoration models to significantly reduce nonphysical dissipation. It has been numerically verified that the END-incorporated models can preserve and recover fine structures satisfactorily, outperforming the basic models for both quality and efficiency. Various numerical examples are shown to demonstrate effectiveness of the END modeling.

A Content Adaptive Fast PDE Algorithm for Motion Estimation Based on Matching Error Prediction

  • Lee, Sang-Keun;Park, Eun-Jeong
    • Journal of Communications and Networks
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    • 제12권1호
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    • pp.5-10
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    • 2010
  • This paper introduces a new fast motion estimation based on estimating a block matching error (i.e., sum of absolute difference (SAD)) between blocks which can eliminate an impossible candidate block much earlier than a conventional partial distortion elimination (PDE) scheme. The basic idea of the proposed scheme is based on predicting the total SAD of a candidate block using its partial SAD. In particular, in order to improve prediction accuracy and computational efficiency, a sub-sample based block matching and a selective pixel-based approaches are employed. In order to evaluate the proposed scheme, several baseline approaches are described and compared. The experimental results show that the proposed algorithm can reduce the computations by about 44% for motion estimation at the cost of 0.0005 dB quality degradation versus the general PDE algorithm.

Thrust - Performance Test of Ethylene-Oxygen Single-Tube Pulse Detonation Rocket

  • Hirano, Masao;Kasahara, Jiro;Matsuo, Akiko;Endo, Takuma;Murakami, Masahide
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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    • pp.205-210
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    • 2004
  • The pulse detonation engine (PDE) has recently expected as a new aerospace propulsion system. The PDE system has high thermal efficiency because of its constant-volume combustion and its simple tube structure. We measured thrust of single-tube pulse detonation rocket (PDR) by two methods using the PDR-Engineering Model (full scale model) for ground testing. The first involved measuring the displacement of the PDR-EM by laser displacement meter, and the second involved measuring the time-averaged thrust by combining a load cell and a spring-damper system. From these two measurements, we obtained 130.1 N of time-averaged thrust, which corresponds to 321.2 sec of effective specific impulse (ISP). As well, we measured the heat flux in the wall of PDE tubes. The heat flux was approximately 400 ㎾/$m^2$. We constructed the PDR-Flight Mode] (PDR-FM). In the vertical flight test in a laboratory, the PDR-FM was flying and keeping its altitude almost constant during 0.3 sec.

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Synthesis and Biological Studies of Catechol Ether Type Derivatives as Potential Phosphodiesterase (PDE) IV Inhibitors

  • Rhee, Chung K.;Kim, Jong-Hoon;Suh, Byung-Chul;Xiang, Myung-Xik;Youn, Yong-Sik;Bang, Won-Young;Kim, Eui-Kyung;Shin, Jae-Kyu;Lee, Youn-Ha
    • Archives of Pharmacal Research
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    • 제22권2호
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    • pp.202-207
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    • 1999
  • New series of catechol ether type derivatives 5, 6 have been synthesized and applied to biological tests. Even though it is ap preliminary data, some of our target molecules show the promising result against PDE IV inhibition. SAR and biological studies with studies with synthetic compounds will be discussed in detail.

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