• Title/Summary/Keyword: 항성

Search Result 638, Processing Time 0.025 seconds

ON THE DYNAMICAL STRUCTURE OF THE JET SYSTEM IN THE DISK WITH THE KEPLERIAN ROTATION (회전 원반계 내 제트 현상의 역학적 구조)

  • 정경숙;최윤정;최규홍;최승언
    • Journal of Astronomy and Space Sciences
    • /
    • v.6 no.1
    • /
    • pp.17-28
    • /
    • 1989
  • The classical solar wind theory proposed by Parker(1963) explains well the dynamics of the wind pheonomena such as stellar wind and accretion disk. While the stellar wind system like the solar wind has the spherically symmetric wind structure, there are various jet phenomena which collimate the system into the narrow space. We can find these dynamical structures in SS433, in the optical jet of M87, and around the active galactic nulei. We present the dynamical structure of the jet system in disks, which conserves the angular monetum, with the Keplerian rotation and the strong relation between the geometrical cross section and the physical change of the jet stream on the basis of the hydrodynamic equations.

  • PDF

Relationship between Body Mass Index and Insulin Resistance and Beta Cell Function by Obesity Type in Obese Middle-Aged Men (비만 중년 남성의 비만 유형별 체질량지수와 인슐린저항성 및 베타세포 기능간의 관련성)

  • Shin, Kyung-A
    • Journal of the Korea Convergence Society
    • /
    • v.11 no.10
    • /
    • pp.155-162
    • /
    • 2020
  • This study wanted to confirm the relevance between body mass index(BMI) and insulin resistance and beta-cell function based on abdominal obesity in obese middle-aged men. This study targeted 797 obese middle-aged men who had undergone health checkups at general hospitals in Gyeonggi-do from January 2018 to June 2020. There were 327 in the group with abdominal obesity and 470 in the group without abdominal obesity. Glucose(p<0.001), HbA1c(p=0.003), insulin(p<0.001), HOMA-IR(p<0.001) was different between groups. BMI was a factor affecting insulin resistance and beta cell function regardless of the with or without of abdominal obesity. BMI was associated with the onset of disease of insulin resistance and beta cell functional degradation regardless of the with or without of abdominal obesity. Therefore, it is considered necessary to manage the indicators of the BMI through exercise programs and regular checkups for health management of middle-aged obese men.

STELLAR POPULATION SYNTHESIS OF THE ELLIPTICAL GALAXY NGC 4649 (타원은하 NGC 4649의 종족합성)

  • 천문석;김문환;손영종
    • Journal of Astronomy and Space Sciences
    • /
    • v.18 no.3
    • /
    • pp.175-190
    • /
    • 2001
  • We investigated population of the elliptical galaxy NGC 4649 using the spectral synthesis technique based on the linear program in the spectral regions between $3160\AA$to $10800\AA$. We used the spectral data of stars obtained by Gunn & Striker (1983), and the integrated spectrum of NGC 4649 observed by Bertola et al. (1982). Among four models with different main sequence turn-off points, G8-K0V main sequence turn-off model is best fitted to the integrated spectrum of NGC 4649. We also found that super metal rich K giants are needed to describe the absorption lines in the long wavelength regions of integrated spectrum of NGC 4649. The mass to absolute light ratio obtained from the spectral synthesis is ~ 20 similar to those calculated dynamically.

  • PDF

Effect of Health Exercise Program on Insulin Resistant and Blood Lipid of Elderly Women Through Convergence (융복합을 활용한 고령여성의 건강운동프로그램이 인슐린저항성 및 혈중지질에 미치는 영향)

  • Kim, Sang-Yeob
    • Journal of Digital Convergence
    • /
    • v.14 no.4
    • /
    • pp.487-494
    • /
    • 2016
  • The purpose of this study was to examine the effect of Health exercise program on insulin resistant and blood lipid factor of elderly women for 12 weeks. The two groups were classified into one group(exercise group: EG) with aerobics exercise and band exercise both, the other group(control group: CG) controled. The group of EG was applied to doing aerobics exercise and band exercise 4 times for 60 minutes a week. The intensity of the exercise was ACSM. Each measurement variable was measured before and after 12 weeks to investigate the effect. During this study the result came out with this step. First, EG have shown interaction with blood lipid(TC, HDL, LDL, TG) and blood pressure(SBP, DBP)factor. Second, EG have shown interaction with insulin resistant(insulin, glucose). Therefore, this study gives us positive result to effect of health exercise program on blood lipid factor and insulin resistant factor of elderly women for 12 weeks.

Spitzer (IRAC & MIPS)+AKARI (FIS) data를 이용한 원시항성의 물리적 성질 연구

  • Ha, Ji-Seong;Lee, Jeong-Eun;Jeong, Ung-Seop
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.35 no.2
    • /
    • pp.66.2-66.2
    • /
    • 2010
  • 별 탄생 초기 진화 단계에 있는 원시항성들은 별 주변 물질들에 의해 둘러싸여 있고, 낮은 온도로 인해 대부분의 에너지를 원적외선 영역에서 방출한다. 그러므로, 원시항성 진화 연구에서 진화단계와 물리적 특성을 바르게 유도하기 위해서는 원적외선 관측이 필수적이다. 본 연구는 원적외선 자료의 중요성을 정량적으로 보이기 위하여 이미 c2d 스피처 레거시 팀에서 동정한 원시성 중, IRAS Point Source Catalog에는 존재하지 않지만, AKARI FIS Catalog에는 존재하는 원시성들을 뽑아내어 AKARI 원적외선 플럭스의 유무에 따른 Bolometric Luminosity와 Bolometric Temperature의 차이를 비교하였다. 뿐만 아니라 AKARI 원적외선 플럭스의 유무에 따라 연속복사전달 모델로부터 얻어지는 물리량, 특히 성간복사장의 세기가 어떻게 달라지는지 연구하였다.

  • PDF

Thermoplastic-nanoimprint lithography 를 위한 유연한 고분자 몰드의 제작

  • Kim, Gang-In;Han, Gang-Su;Lee, Heon
    • Proceedings of the Materials Research Society of Korea Conference
    • /
    • 2010.05a
    • /
    • pp.24.2-24.2
    • /
    • 2010
  • 고분자 몰드를 이용한 nanoimprint lithography (NIL)는 고분자소재의 유연성과 투명성으로 인하여, 유기전자소자나 유연한 디스플레이소자 등 다양한 응용이 가능하다. 하지만, 고분자소재는 일반적으로 열저항성과 내구성이 낮아서, 고분자 몰드를 이용한 패턴형성 시, 자외선 경화방식이 주로 사용된다. 만약 복제가 쉽고, 가격이 저렴하며, 열저항성과 내구성이 강한 고분자 몰드를 제작한다면, thermoplastic-NIL 기술에 적용할 수가 있기 때문에, 고온을 요구하는 소자의 패턴형성 공정에 사용 가능하다. 본 연구에서는 이러한 고분자 몰드 제작을 위하여, 열저항성과 내구성이 강한 polyimide 필름과 polyurethane acrylate (PUA)를 기반으로 제작된 resin을 이용하였다. 먼저 Polyimide 필름 위에 자외선 노광을 사용하여, PUA resin 을 경화시킴으로써 패턴을 형성하였다. 이렇게 만들어진 몰드를 thermoplastic-NIL기술에 적용함으로써, Si 기판 위에 sub-마이크로 급 패턴을 형성하였다. 또한, 제작된 고분자 몰드를 사용하여 반복적인 NIL 공정을 수행함으로써 몰드의 내구성을 확인하였으며, 곡면 기판 위에 NIL을 함으로써 몰드의 유연성을 확인 할 수 있었다.

  • PDF

Resistance of Varieties to Rice Blast in Korea 2. Tongil Type of Rice Varieties (한국(韓國) 수도품종(手稻品種)의 도열병(稻熱病) 저항성(抵抗性)에 관(關)하여 2. 통일형(統一型) 품종(品種))

  • Choi, Jea Eul;Park, Jong Seong;Park, Nam Kyu
    • Korean Journal of Agricultural Science
    • /
    • v.16 no.2
    • /
    • pp.129-137
    • /
    • 1989
  • This experiment was undertaken to clarify derivation of resistance of Tongil type of rice varieties to rice blast in Korea and to classify Tongil type of rice varieties on the basis of their rice blast reactions in th blast nursery test. 1. The resistance of Tongil, Josaengtongil, Yeongnamjosaeng, Hwanggeumbyeo, Honamjosaeng, Noupung, Milyang 21, Milyang 22, Milyang 23, Raekyung, Manseogbyeo, Yongmunbyeo and Yongjubyeo to rice blast was derived from IR 8 or IR 24. 2. The resistance of Milyang 20, Nampungbyeo and Milyang 42, and Samseongbyeo, Seogwangbyeo, Pungsanbyeo and Shingwangbyeo to the rice blast was derived from IR 946 and IR 1539, and IR 1545, respectively. 3. The resistance of Palgwangbyeo, Sujeongbyeo, Hangangchalbyeo, Baegunchalbyeo, Samgangbyeo and Weonpungbyeo, and Taebaegbyeo and Chupungbyeo, and Kayabyeo to the rice blast was derived from IR 2061(IR 29), IR 747 and IR 32, respectively. 4. Cheongcheongbyeo, and Jungweonbyeo and Namyeongbyeo, and Changseongbyeo to the rice blast was derived from IR 2035, IR 5533, and HR 2797 and HR 1671, respectively. 5. Tongil type of rice varieties was classified into Tongil group, Milyang 30 group, Baegyangbyeo group and Taebaegbyeo group.

  • PDF

DISK OF Be STAR WITH EMISSION (Hα 방출선을 통한 Be 항성 원반)

  • Ahn, Dae-Gun;Bae, Jang-Ho;Lee, Sang-Gak;Shin, Young-Woo;Ko, Yeon-Gyung;Kang, Suk-Chul
    • Publications of The Korean Astronomical Society
    • /
    • v.22 no.4
    • /
    • pp.133-140
    • /
    • 2007
  • We have determined the disk size of Be stars by using $H{\alpha}$ emission. We observed spectra of Be stars with telescope in SNU, equipped with SB SGS (Santa Babara Self Guided Spectrograph) and CCD ST-8. The size of disk of Be stars was estimated with the Be star model of Grundstrom & Gies (2006). This study suggests that the medium resolution spectra taken with small telescope equipped with commercial spectrograph are useful to estimate the approximate size of the $H{\alpha}$ emitting disk around Be stars.

의상고성(儀象考成) 항성황적경위도표(恒星黃赤經緯度表)에 실린 별들의 동정

  • Jeon, Jun-Hyeok;Kim, Dong-Bin;Lee, Yong-Sam
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.36 no.1
    • /
    • pp.25.2-25.2
    • /
    • 2011
  • 의상고성(儀象考成)에 수록된 항성황적경위도표(恒星黃赤經緯度表)는 청대(靑代) 흠천감(欽天監) 감정(監正)이었던 대진현(戴進賢, Ignatius Koegler, 1680-1746)이 3083개의 별들의 위치와 등급을 수록하여 1752년에 출판한 성표이다. 우리는 Yale Bright Star Catalogue 5차본을 이용하여 의상고성에 실린 별들을 동정하였다. 동정의 결과를 통해 성표의 정확도를 파악하였고, 일부 데이터가 오기되었거나 중복 기록되었음을 확인하였다. 그리고 황경에 따른 황위의 오차 분포를 통해 당시에 황적도 좌표 변환에 사용된 황도 경사각 값을 추정하였다.

  • PDF