• 제목/요약/키워드: MIR

검색결과 303건 처리시간 0.025초

Extragalactic Research Highlights of AKARI - From Nearby Galaxies to Quasars in the Early Universe -

  • 임명신
    • 천문학회보
    • /
    • 제35권1호
    • /
    • pp.77.1-77.1
    • /
    • 2010
  • I summarize highlights from extragalactic research activities performed with AKARI infrared space telescope. The main emphasis will be given to the works carried out by Korean astronomers. The activities span a wide range of topics, such as MIR properties of nearby galaxies in cluster environment, MIR diagnosis of star-forming galaxies at z=0 through z=2 in the North Ecliptic Pole (NEP) survey field, the Extended Groth Strip (EGS), and the First Look Survey (FLS) field, and the NIR spectroscopy of Luminous Infrared Galaxies (LIRGs) and Active Galactic Nuclei/Super-massive Black Holes at low redshift as well as near the re-ionization epoch of z~6. I describe FIR and MIR all sky data which can be used as a precious resource for extragalactic research, and other future and ongoing works with AKARI. These AKARI results will form a strong basis for future studies using other facilities, such as infrared surveys with UKIRT, FIR study of dusty universe with Herschel, and the SPICA mission.

  • PDF

표면층 제거에 대한 비정질 금속 $\textrm{Co}_{66}\textrm{Fe}_{4}\textrm{NiB}_{14}\textrm{Si}_{15}$의 자기임피턴스 효과 (Magnetoimpedance(MI) Effect due to the Removal of Skin Layer in Amorphous Metal $\textrm{Co}_{66}\textrm{Fe}_{4}\textrm{NiB}_{14}\textrm{Si}_{15}$)

  • 조완식;김종오;이희복
    • 한국재료학회지
    • /
    • 제7권9호
    • /
    • pp.728-732
    • /
    • 1997
  • 비정질 금속 $Co_{66}$F $e_{4}$Ni $B_{14}$S $i_{15}$ 의 표면층 제거에 대한 자기임피턴스 효과는 시료의 길이방향에 평행한 일축자기장에 대하여 측정하였다. MIR(Magnetoimpedance Ratios)은 비정질 금속의 두께가 얇아짐에 따라 감소하고, 전류에 비례하여 증가하는 경향을 나타내었다. 인가전류 주파수에 대한 MIR과 자기장의 감도는 모든 시료에서 주파수에 비례하여 증가하며 수 MHz 부근에서 최대값을 가지고 점차 감소하는 경향을 나타내었다. 시료의 표면층제거에 기인한 이방성자기장의 변화는 MI $R_{Max}$을 나타내는 외부 자기장을 감소시키지만, MIR은 표면층 제거에 따른 부피효과에 기인하여 감소하였다....

  • PDF

THEORY AND PRINCIPLES OF NEAR INFRARED SPECTROSCOPY

  • Barton, Franklin E.
    • 한국근적외분광분석학회:학술대회논문집
    • /
    • 한국근적외분광분석학회 2001년도 NIR-2001
    • /
    • pp.1012-1012
    • /
    • 2001
  • The elegant early experiments of Herschel demonstrated that there is light after the visible spectrum in a region we call the near infrared (NIR). This was followed by the work which showed that the spectrum went further into what we call the mid infrared (MIR). The MIR has been used for many years as a qualitative and quantitative region to measure constituent values. The MIR region contains the fundamental vibrations which can be theoretically calculated from symmetry rules and harmonic oscillator equations. The NIR is not as straight forward because the region from 400-2500 nm does not contain any of the fundamental vibrations only combination bands and overtones. Over the past fifty years efforts to understand the NIR have largely been ignored while the quantitative aspects of the region have been utilized. This presentation will focus on the efforts to define terms for NIR, examine the calculation of combination bands and overtones and ways to interpret the spectra. The interpretation of the NIR has been aided greatly in recent years by the use of two dimensional spectroscopy which allows the correlation of bands in one spectral region with that of the NIR.

  • PDF

천리안2A호를 이용한 다목적실용위성3A호 중적외선 밝기 온도 편향오차 개선 가능성 연구 (A Study on Possibility of Improvement of MIR Brightness Temperature Bias Error of KOMPSAT-3A Using GEOKOMPSAT-2A)

  • 김희섭
    • 한국항공우주학회지
    • /
    • 제48권12호
    • /
    • pp.977-985
    • /
    • 2020
  • 2015년 발사된 다목적실용위성 3A호는 3.3~5.2㎛ 파장의 중적외선 영상을 제공한다. 다목적실용위성 3A호는 지상 물체의 밝기 온도를 추정하기 위한 고해상도 영상을 제공하지만 기존 자연 과학 목적으로 개발된 위성과 차이가 있다. 다목적실용위성 3A호의 단일 채널의 중적외선 영상으로 지표 밝기 온도를 추정하기 위해서는 대기 보정 과정이 필수적이다. 하지만 대기 보정 이후에도 여러 요인으로 인하여 밝기 온도 추정 오차가 존재한다. 본 논문에서는 다목적실용위성 3A호 카메라의 물리적인 특성으로부터 영상 처리까지 신호 흐름을 추적하여 밝기 온도 추정 오차 요인을 분석하였다. 또한, 천리안위성 2A호를 이용하여 다목적실용위성 3A호와 밝기 온도 편향 오차 개선 가능성을 연구하였다. 큰 편향 오차를 가지고 있는 야간 영상에 대하여 편향 오차를 보상한 이후 다목적실용위성 3A호와 천리안위성 2A호의 지표 밝기 온도가 상관성이 있음을 확인하였다. 다목적실용위성 3A호 중적외선 밝기 온도 편향 오차를 개선하는데 천리안위성 2A호 영상이 도움이 될 것으로 예상된다.

A WISE View of E+A Galaxies

  • 고종완;황호성;손영종
    • 천문학회보
    • /
    • 제36권2호
    • /
    • pp.66.1-66.1
    • /
    • 2011
  • E+A galaxies are interpreted as post-starburst systems because of strong Balmer absorption lines but any emission lines indicating the lack of current star formation activities, thus they are one of key populations for understanding how star formation activities evolve in galaxies. We present mid-infrared (MIR) spectral energy distributions of E+A galaxies using the Wide-field Infrared Survey Explorer (WISE) preliminary released data. Furthermore, we investigate the role of environment with respect to the MIR properties of E+A galaxies.

  • PDF

건설 분야 신뢰성 향상을 위한 경영표준 운영 방안 (On the Standardization of Management System for Improving Reliability in Construction Industry)

  • 김종걸;박용수
    • 대한안전경영과학회:학술대회논문집
    • /
    • 대한안전경영과학회 2004년도 추계학술대회
    • /
    • pp.253-258
    • /
    • 2004
  • Domestic construction industry (including plant engineering industry) faces severe competition with world-wide leading companies under WTO (World Trade Organization) system. To survive in this competition, domestic construction company should establish and operate standardization system efficiently. In this paper, check list is presented to prepare the efficient reliability management system in domestic construction. And then, the check list is applied in MIR(Maturity Index on Reliability) estimation item to estimate reliability management level of company quantitatively.

  • PDF

Association of mir-499 and mir-149 Polymorphisms with Cancer Risk in the Chinese Population: Evidence from Published Studies

  • Zhang, You-Gai;Shi, Jian-Xiang;Song, Chun-Hua;Wang, Peng;Dai, Li-Ping;Zhang, Jian-Ying;Shi, Jia-Chen
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제14권4호
    • /
    • pp.2337-2342
    • /
    • 2013
  • Meta-analyses have shown that microRNA polymorphisms have variable effects in different population. Yet, no meta-analysis investigated the association of two common polymorphisms of miRNA, mir-499 rs3746444 polymorphism and mir-149 rs2292832 polymorphism, with cancer risk in the Chinese population. We searched the PubMed, Web of Knowledge, MEDLINE, CNKI databases, as well as Cochrane library, updated on December 31, 2012 for assays regarding cancer risk association with these two common polymorphisms in the present meta-analysis. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to explore the strength of associations. The results showed that rs3746444 polymorphism was associated with increased cancer risk (dominant model: GG/AG vs. AA: OR = 1.43, 95% CI: 1.14-1.80; recessive model: GG vs. AG/AA: OR = 1.54, 95% CI: 1.04-2.30; homozygote model: GG vs. AA: OR = 1.69, 95% CI: 1.10-2.60; heterozygote model: AG vs. AA: OR = 1. 35, 95% CI: 1.09-1.67), and rs3746444 was associated with liver cancer in the subgroup of cancer types. For the rs2292832 polymorphism, the results showed no significant risk association in both overall pooled analysis and subgroup of cancer types, smoking status, gender and tea drinking status in the Chinese population. This meta-analysis suggested that the rs3746444 GG genotype is associated with increased cancer risk, especially liver cancer, while the rs2292832 polymorphism showed no association with cancer risk in Chinese.

Elucidation of the Molecular Interaction between miRNAs and the HOXA9 Gene, Involved in Acute Myeloid Leukemia, by the Assistance of Argonaute Protein through a Computational Approach

  • Das, Rohit Pritam;Konkimalla, V. Badireenath;Rath, Surya Narayan;Hansa, Jagadish;Jagdeb, Manaswini
    • Genomics & Informatics
    • /
    • 제13권2호
    • /
    • pp.45-52
    • /
    • 2015
  • Acute myeloid leukemia is a well characterized blood cancer in which the unnatural growth of immature white blood cell takes place, where several genes transcription is regulated by the micro RNAs (miRNAs). Argonaute (AGO) protein is a protein family that binds to the miRNAs and mRNA complex where a strong binding affinity is crucial for its RNA silencing function. By understanding pattern recognition between the miRNAs-mRNA complex and its binding affinity with AGO protein, one can decipher the regulation of a particular gene and develop suitable siRNA for the same in disease condition. In the current work, HOXA9 gene has been selected from literature, whose deregulation is well-established in acute myeloid leukemia. Four miRNAs (mir-145, mir-126, let-7a, and mir-196b) have been selected to target mRNA of HOXA9 (NCBI accession No. NM_152739.3). The binding interaction between mRNAs and mRNA of HOXA9 gene was studied computationally. From result, it was observed mir-145 has highest affinity for HOXA9 gene. Furthermore, the interaction between miRNAs-mRNA duplex of all chosen miRNAs are docked with AGO protein (PDB ID: 3F73, chain A) to study their interaction at molecular level through an in silico approach. The residual interaction and hydrogen bonding are inspected in Discovery Studio 3.5 suites. The current investigation throws light on understanding of AGO-assisted miRNA based gene silencing mechanism in HOXA9 gene associated in acute myeloid leukemia computationally.

MID- AND FAR-INFRARED PROPERTIES OF LOCAL ACTIVE GALACTIC NUCLEI

  • Ichikawa, Kohei;Ueda, Yoshihiro;Terashima, Yuichi;Oyabu, Shinki;Gandhi, Poshak;Matsuta, Keiko;Nakagawa, Takao
    • 천문학논총
    • /
    • 제27권4호
    • /
    • pp.275-279
    • /
    • 2012
  • We investigate the mid-infrared (MIR) to far-infrared (FIR) properties of a nearly complete sample of local active galactic nuclei (AGNs) detected in the Swift/Burst Alert telescope (BAT) all-sky hard X-ray (14-195 keV) survey, based on the cross correlation with the infrared survey catalogs of AKARI, IRAS and WISE. Out of 135 non-blazar AGNs in the Swift/BAT 9-month catalog, we obtain the MIR photometric data for 128 sources in either the 9, 12, 18, 22, and $25{\mu}m$ band. We find a good correlation between their hard X-ray and MIR luminosities ranging three orders of magnitude (42 < log ${\lambda}L_{\lambda}$(9, $18{\mu}m$) < 45), which is tighter than that with the FIR luminosities at $90{\mu}m$. Both X-ray unabsorbed and absorbed AGNs follow the same correlation, implying isotropic infrared emission, as expected in clumpy dust tori models rather than homogeneous ones.

내용 기반 멀티미디어 정보 검색을 위한 근사 k-최근접 데이타 탐색 알고리즘 (An Approximate k-Nearest Neighbor Search Algorithm for Content- Based Multimedia Information Retrieval)

  • 송광택;장재우
    • 한국정보과학회논문지:데이타베이스
    • /
    • 제27권2호
    • /
    • pp.199-208
    • /
    • 2000
  • 내용 기반 멀티미디어 정보 검색에서 유사성에 기반한 k-최근접 데이타 탐색 질의는 매우 중요한 질의이다 일반적으로 멀티미디어 데이타는 고차원 특정 벡터로 표현되기 때문에 기존의 k-최근접 탐색 알고리즘은 멀티미디어 정보 검색에 효율적이지 못하다. 따라서 이러한 응용을 위해서는 다소 근사적 검색 결과를 가져오더라도 빠른 검색 성능을 제공하는 근사 k-최근접 탐색 알고리즘이 요구된다. 이를 위해 본 논문에서는 고차원 데이타를 위한 새로운 근사 k-최근접 탐색 알고리즘을 제안한다. 아울러, 제안하는 근사 k-최근접 탐색 알고리즘을 기존의 알고리즘과 검색 성능변에서 성능 평가를 수행한다. 성능 평가 결과, 기존 알고리즘의 검색 성능을 크게 개선할 수 있었다.

  • PDF