• 제목/요약/키워드: POL

검색결과 282건 처리시간 0.026초

소형 마이크로스트립 패치 안테나 (A Small Microstrip Patch Antenna)

  • 장순범;박동국
    • 한국전자파학회논문지
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    • 제14권4호
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    • pp.351-355
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    • 2003
  • 본 논문에서는 누설 전계(fringing field)가 일어나는 패치 종단 부분은 그대로 두고 전송선로로 등가해석할 수 있는 패치 중앙 부분의 전기적인 경로를 변화시켜 안테나를 소형화하였다. 시뮬레이션 툴은 Ensemble을 사용하였으며 제안된 안테나를 일반적인 마이크로스트립 안테나와 소형화 정도, 이득, 대역폭, 복사패턴 등을 비교하였다. 결과적으로 제안된 안테나는 일반적인 정사각형 마이크로스트립 안테나에 비하여 대역폭이 감소되는 단점 이 있는 반면 안테나의 면적 이 44 % 가량 감소되었으며, X-pol 특성 이 40 dB 가량 개선되는 결과를 나타내었다.

Evaluation of Polarimetric Parameters for Flood Detection Using PALSAR-2 Quad-pol Data

  • Jung, Yoon Taek;Park, Sang-Eun;Baek, Chang-Sun;Kim, Dong-Hwan
    • 대한원격탐사학회지
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    • 제34권1호
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    • pp.117-126
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    • 2018
  • This study aims to evaluate the usability of polarimetric SAR measurements for discriminating water-covered area from other land cover types and to propose polarimetric parameters showing the better response to the flood. Flood-related changes in the polarimetric parameters were studied using the L-band PALSAR-2 quad-pol mode data acquired before and after the severe flood events occurred in Joso city, Japan. The experimental results showed that, among various polarimetric parameters, the HH-polarization intensity, the Shannon entropy, and the surfaces scattering component of model-based decomposition were found to be useful to discriminate water-covered areas from other land cover types. Particularly, an unsupervised change detection with the Shannon entropy provides the best result for an automated mapping of flood extents.

Roles of the Conserved Carboxylic Residues in the Active-Site of 5'-3' Exonuclease of Taq DNA Polymerase

  • Kim, Young-Soo;Shin, Joong-Chul
    • Journal of Microbiology and Biotechnology
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    • 제9권4호
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    • pp.381-385
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    • 1999
  • Taq DNA polymerase from Thermus aquaticus has been shown to be very useful in a polymerase chain reaction. Taq DNA polymerase has a domain at the amino terminus (residues 1 to 290) that has 5'-3' exonuclease activity and a domain at the C-terminus that catalyzes the polymerase reaction. Taq DNA polymerase is classified into the Pol I family, which is represented by E. coli DNA polymerase I. The alignment of amino acid sequences for the 5'-3' exonuclease domains of the Pol I family DNA polymerases shows ten highly conserved carboxylic amino acids. Crystallographic studies suggested that six of the carboxylic amino acids are clustered within a 7 $\AA$ radius by chelating three metal ions in the active site. Those six carboxylic residues are mutagenized to alanines in order to better understand their function. All six carboxylic residues, Asp l8, Glu1l7, Asp1l9, Asp120, Asp142, and Aspl44, are crucial for catalysis of 5'-3' exonuclease.

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A study on Synchronization method for Mutual Cooperative Control in the Chaotic UAV

  • Bae Young-Chul;Kim Chun-Suk;Koo Young-Duk
    • Journal of information and communication convergence engineering
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    • 제4권1호
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    • pp.28-35
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    • 2006
  • In this paper, we propose to synchronization method for mutual cooperative control method that have unstable limit cycles in a chaos trajectory surface in the chaotic UAVs. We assume all obstacles in the chaos trajectory surface have a Van der Pol equation with an unstable limit cycle. We also show computer simulation results of Arnold equation, Chua's equation trajectories with one or more Van der Pol as a obstacles. We proposed and verified the results of the method to make the embedding chaotic UAV to synchronization with the chaotic trajectory in any plane.

A Novel Type of Non-coding RNA, nc886, Implicated in Tumor Sensing and Suppression

  • Lee, Yong Sun
    • Genomics & Informatics
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    • 제13권2호
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    • pp.26-30
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    • 2015
  • nc886 (=vtRNA2-1, pre-miR-886, or CBL3) is a newly identified non-coding RNA (ncRNA) that represses the activity of protein kinase R (PKR). nc886 is transcribed by RNA polymerase III (Pol III) and is intriguingly the first case of a Pol III gene whose expression is silenced by CpG DNA hypermethylation in several types of cancer. PKR is a sensor protein that recognizes evading viruses and induces apoptosis to eliminate infected cells. Like viral infection, nc886 silencing activates PKR and induces apoptosis. Thus, the significance of the nc886:PKR pathway in cancer is to sense and eliminate pre-malignant cells, which is analogous to PKR's role in cellular innate immunity. Beyond this tumor sensing role, nc886 plays a putative tumor suppressor role as supported by experimental evidence. Collectively, nc886 provides a novel example how epigenetic silencing of a ncRNA contributes to tumorigenesis by controlling the activity of its protein ligand.

A Obstacle Avoidance in the Chaotic Robot for Ubiquitous Environment

  • 배영철
    • 한국지능정보시스템학회:학술대회논문집
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    • 한국지능정보시스템학회 2005년도 공동추계학술대회
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    • pp.197-204
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    • 2005
  • In this paper, we propose a method to an obstacle avoidance of chaotic robots that have unstable limit cycles in a chaos trajectory surface in the ubiquitous environment. We assume all obstacles in the chaos trajectory surface have a Van der Pol equation with an unstable limit cycle. We also show computer simulation results of Chua's equation, Lorenz equation, Hamilton and Hyper-chaos equation trajectories with one or more Van der Pol as an obstacles. We proposed and verified the results of the method to make the embedding chaotic mobile robot to avoid with the chaotic trajectory in any plane.

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Obstacle Avoidance in the Chaos Mobile Robot

  • Bae, Young-Chul;Kim, Yi-Gon;Mathis Tinduk;Koo, Young-Duk
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2004년도 SMICS 2004 International Symposium on Maritime and Communication Sciences
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    • pp.100-105
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    • 2004
  • In this paper, we propose a method to avoid obstacles that have unstable limit cycles in a chaos trajectory surface. We assume all obstacles in the chaos trajectory surface have a Van der Pol equation with an unstable limit cycle. When a chaos robot meets an obstacle in a Lorenz equation or Hamilton equation trajectory, the obstacle reflects the robot. We also show computer simulation results for avoidance obstacle which fixed obstacles and hidden obstacles of Lorenz equation and Hamilton equation chaos trajectories with one or more Van der Pol obstacles

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Glass Ionomer Cement의 변록누출(邊綠漏出)에 관(關)한 실험적(實驗的) 연구(硏究) (AN EXPERIMENTAL STUDY ON THE MARGINAL LEAKAGE OF GLASS IONOMER CEMENT)

  • 주광섭;유근원
    • Restorative Dentistry and Endodontics
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    • 제7권1호
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    • pp.101-106
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    • 1981
  • The purpose of this study was to estimate the ability of the marginal fit of Glass ionomer cement. Using the human extracted teeth and 2% acqueous solution of methylene blue, the author investigated the marginal penetration of dye in restorative materials such as Amalgam, Hi-Pol, Glass ionomer cement, Estic microfill and Restodent. The results were as follows. 1. All filling materials showed some degree of marginal penetration. 2. Glass ionomer cement revealed nearly the same microleakage as Estic microfill and Hi-Pol, but showed inferior effect of the marginal seal as compared with Restodent. 3. It is appeared that Amalgam has more effective ability of the marginal fit than the others within a week.

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산(酸) 부식처리(腐蝕處理)된 치아표면(齒牙表面)에 대(對)한 복합(複合)레진의 침투(浸透)에 관(關)한 실험적(實驗的) 연구(硏究) (AN EXPERIMENTAL STUDY ON THE PENETRATION OF RESTORATIVE RESINS INTO ACID-ETCHED HUMAN ENAMEL)

  • 이승종
    • Restorative Dentistry and Endodontics
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    • 제5권1호
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    • pp.7-12
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    • 1979
  • After applying three types of composite resins - Hi-Pol composite with Enamel bond, Hi-Pol composite without Enamel bond, Restodent - to the intact and the ground surface of tooth that had been acid etched for one or two minutes, the author observed the penetration of these resins into the acid etched enamel surface with scanning electron microscope. The results were as follows. 1. All the experimented materials showed the penetration into the acid etched enamel surface, and the average depth of penetration was 7 microns. 2. There was no significant difference in the penetration of these three resins despite different etching, time. 3. The grinding of the Enamel surface before acid - etching was not effective in altering the depth of penetration of these materials.

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Filaments and Dense Cores in IC5146: Roles of Gravity, Turbulence, and Magnetic Field

  • Chung, Eun Jung
    • 천문학회보
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    • 제45권1호
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    • pp.42.1-42.1
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    • 2020
  • Filamentary structures pervade the whole kind of molecular clouds from low- to high-mass star-forming clouds, and the non-star-forming clouds. It is supposed to be a prerequisite stage of star formation, and hence how filaments and dense cores form is one of the critical questions in the early star formation study. We investigated the dynamics and chemistry of dense cores in IC5146 using TRAO FUNS (TRAO Survey of the nearby Filamentary molecular clouds, the Universal Nursery of Stars) data. In addition, we performed polarization observation using JCMT Pol-2 polarimetry to investigate the magnetic field morphology within a core-scale. In the presentation, we will present the result of TRAO FUNS and JCMT/Pol2 observation toward the filaments and dense cores in the IC5146. We aim to reveal the roles of gravity, turbulence, and magnetic field in the formation of dense cores in the western hub-filament structure of IC5146.

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