• Title/Summary/Keyword: UT

Search Result 483, Processing Time 0.029 seconds

An MHD Simulation of the X2.2 Solar Flare on 2011 February 15

  • Inoue, Satoshi;Choe, Gwangson
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.39 no.1
    • /
    • pp.69.1-69.1
    • /
    • 2014
  • We perform an MHD simulation combined with observed vector field data to clarify an eruptive dynamics in the solar flare. We first extrapolate a 3D coronal magnetic field under a Nonlinear Force-Free Field (NLFFF) approximation based on the vector field, and then we perform an MHD simulation where the NLFFF prior to the flare is set as an initial condition. Vector field was obtained by the Soar Dynamics Observatory (SDO) at 00:00 UT on February 15, which is about 90 minutes before the X2.2-class flare. As a result, the MHD simulation successfully shows an eruption of strongly twisted lines whose values are over one-turn twist, which are produced through the tether-cut magnetic reconnection in strongly twisted lines of the NLFFF. Eventually, we found that they exceed a critical height at which the flux tube becomes unstable to the torus instability determining the condition that whether a flux tube might escape from the overlying field lines or not. In addition to these, we found that the distribution of the observed two-ribbon flares is similar to the spatial variance of the footpoints caused by the reconnection of the twisted lines being resided above the polarity inversion line. Furthermore, because the post flare loops obtained from MHD simulation well capture that in EUV image taken by SDO, these results support the reliability of our simulation.

  • PDF

Reform of sacrificial ritual model through the empirical tests of reformative model far Korean sacrificial rite (제례 재구성 모델의 실증적 검증을 통한 제례 모델 재구성)

  • 두경자
    • Journal of Families and Better Life
    • /
    • v.19 no.6
    • /
    • pp.241-263
    • /
    • 2001
  • The objectives of this study were empirically to test the reformative model for Korean sacrificial rite and to investigate the effects of demographic variables. the survey was conducted by means of questionnaire with 600 persons located in Seoul. Major findings were as follows ; 1, Sacrificial day ; was displayed (1) dead day (2) holiday in back and forth of dead day 2. Sacrificial time ; was showed (1) 8-9 h. p.m (2) 6-7 h. p.m 3. Sacrificial extent ; was displayed (1) grandparents and parents (2) only parents 4. Participative extent ; was showed (1) Cousin (2) only sons and daughters 5. Sacrificial procedure ; was displayed twice deep bow and 1 minute\`s silent prayer. 6. New year's and Chusok's rite ; was showed (1) simple foods (2) joint leisure time 7. Sacrificial table ; was displayed (1) boiled rice . water . gustoish articles. (2) omission of food table 8. rite\`s socialization ; was showed (1) delivery and marketing sale\`s food (2) special sacrificial restaurant. 9. Womens'and mens'difference ; women were active 7ut men were passive 10. Age's difference ; excepting 30-40, the all generations were more reformative. 11. Number of brothers ; small number of brothers were more reformative than a many number. 12. Sacrificial manager or not , managers were conservative than persons were not managers.

  • PDF

Modeling and Simulation on Ion Implanted and Annealed Indium Distribution in Silicon Using Low Energy Bombardment (낮은 에너지로 실리콘에 이온 주입된 분포와 열처리된 인듐의 거동에 관한 시뮬레이션과 모델링)

  • Jung, Won-Chae
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.29 no.12
    • /
    • pp.750-758
    • /
    • 2016
  • For the channel doping of shallow junction and retrograde well formation in CMOS, indium can be implanted in silicon. The retrograde doping profiles can serve the needs of channel engineering in deep MOS devices for punch-through suppression and threshold voltage control. Indium is heavier element than B, $BF_2$ and Ga ions. It also has low coefficient of diffusion at high temperatures. Indium ions can be cause the erode of wafer surface during the implantation process due to sputtering. For the ultra shallow junction, indium ions can be implanted for p-doping in silicon. UT-MARLOWE and SRIM as Monte carlo ion-implant models have been developed for indium implantation into single crystal and amorphous silicon, respectively. An analytical tool was used to carry out for the annealing process from the extracted simulation data. For the 1D (one-dimensional) and 2D (two-dimensional) diffused profiles, the analytical model is also developed a simulation program with $C^{{+}{+}}$ code. It is very useful to simulate the indium profiles in implanted and annealed silicon autonomously. The fundamental ion-solid interactions and sputtering effects of ion implantation are discussed and explained using SRIM and T-dyn programs. The exact control of indium doping profiles can be suggested as a future technology for the extreme shallow junction in the fabrication process of integrated circuits.

A HIGH FREQUENCY TYPE II SOLAR RADIO BURST ASSOCIATED WITH THE 2011 FEBRUARY 13 CORONAL MASS EJECTION

  • Cho, Kyungsuk;Gopalswamy, Nat;Kwon, Ryunyoung;Kim, Roksoon;Yashiro, Seiji
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.37 no.2
    • /
    • pp.111.1-111.1
    • /
    • 2012
  • We examine the relationship between a type II radio burst that started from an unusually high frequency of 425 MHz (fundamental component) and an associated white-light coronal mass ejection on 2011 February 13. The radio burst had a drift rate of 2.5 MHz/sec, indicating a relatively high shock speed. From SDO AIA observations we find that a loop-like erupting front sweeps across high density coronal loops near the start time of the burst (17:34:15 UT). We find fragmented structures of the type II burst, which indicates the signature of the shock propagating through the multiple loops. The deduced distance of shock formation (0.06 Rs) from flare center and speed of the shock (1100 km $s^{-1}$) using the measured density from AIA/SDO observations are comparable to the height (0.05 Rs, from the solar surface) and speed (700 km $s^{-1}$) of the CME leading edge observed by STEREO/EUVI. We conclude that the type II burst could be onset even in the low corona (41 Mm or 0.06 Rs, above the solar surface) if a fast CME shock passes through the high density loops.

  • PDF

Cloning and Expression of a Full-Length Glutamate Decarboxylase Gene from Lactobacillus plantarum

  • Park, Ki-Bum;Oh, Suk-Heung
    • Preventive Nutrition and Food Science
    • /
    • v.9 no.4
    • /
    • pp.324-329
    • /
    • 2004
  • In order to investigate the molecular mechanism of $\gamma$-aminobutyric acid (GABA) production in lactic acid bacteria, we cloned a glutamate decarboxylase (GAD) gene from Lactobacillus plantarum using polymerase chain reaction (PCR). One PCR product DNA was obtained and inserted into a TA cloning vector with a T7 promoter. The recombinant plasmid was used to transform E. coli. The insertion of the product was con­firmed by EcoRI digestion of the plasmid purified from the transformed E. coli. Nucleotide sequence analysis showed that the insert is a full-length Lactobacillus plantarum GAD and that the sequence is $100\%$ and $72\%$ identical to the regions of Lactobacillus plantarum GAD and Lactococcus lactis GAD sequences deposited in GenBank, accession nos: NP786643 and NP267446, respectively. The amino acid sequence deduced from the cloned Lactobacillus plantarum GAD gene showed $100\%$ and $68\%$ identities to the GAD sequences deduced from the genes of the NP786643 and NP267446, respectively. To express the GAD protein in E. coli, an expression vector with the GAD gene (pkk/GAD) was constructed and used to transform the UT481 E. coli strain and the expression was confirmed by analyzing the enzyme activity. The Lactobacillus plantarum GAD gene obtained may facilitate the study of the molecular mechanisms regulating GABA metabolism in lactic acid bacteria.

The Design of Video Compression Browsing for Low Capacity and High Quality (저용량, 고화질 비디오 압축 브라우징에 대한 설계)

  • 강진석;김무영;김장형
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 1999.11a
    • /
    • pp.193-198
    • /
    • 1999
  • In the 21th century, everyone feels that the multimedia system is close at hand in real life due to the rapid advance of the computer processing ability and high speed and high guality of communication services. Also the limited frequencies resource will be optimized due to rapid advances in digital video technology which is believed superior to analogue technology in information engineering. MEPG-2 has been introduced for broadcasting use such as digital TV Thus it features the high-definition and hyper-low bit rate. But, because of much throughput it has been implemented by high-priced private ASIC chip and is not in general use yet. But in this research, noticing the rapid enhancement of PC processor performance comparing with the price. MPEG-2 was developed by real time software MPEG-2 had been known impossible to implement with S/W, but the research proved the possibility of the S/W implementation and below are the pictures also in the research was improved 'Motion Vector and Compensation' Algorithm which requires the most operations and UT was made possible real time process. Multimedia Info Society has settled and accompanied by the rapid advance of image-processing technology and lots of standards.

  • PDF

Sensorless speed control of Permanent Magnet Synchronous Motor by Unscented Kalman filter (무향 칼만 필터에 의한 영구자석 동기 전동기 센서리스 속도제어)

  • Moon, Cheol;Kwon, Young-Ahn
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.16 no.5
    • /
    • pp.967-972
    • /
    • 2012
  • In order to implement good control of the permanent magnet synchronous motor(PMSM), the exact speed and rotor position information is needed.Recently, many studies have performed about sensorless speed control of the PMSM. This paper proposed sensorless speed controls of PMSM by using the Unscented Kalman Filter(UKF).The UKF is designed to eliminate the noise and get to the accuracy value and deals with the estimation of the speed and the rotor position of PMSM. Simulation and experiment have been performed for the verification of the proposed algorithm.

Changes in the Earth's Spin Rotation due to the Atmospheric Effects and Reduction in Glaciers

  • Na, Sung-Ho;Cho, Jungho;Kim, Tu-Hwan;Seo, Kiweon;Youm, Kookhyoun;Yoo, Sung-Moon;Choi, Byungkyu;Yoon, Hasu
    • Journal of Astronomy and Space Sciences
    • /
    • v.33 no.4
    • /
    • pp.295-304
    • /
    • 2016
  • The atmosphere strongly affects the Earth's spin rotation in wide range of timescale from daily to annual. Its dominant role in the seasonal perturbations of both the pole position and spinning rate of the Earth is once again confirmed by a comparison of two recent data sets; i) the Earth orientation parameter and ii) the global atmospheric state. The atmospheric semi-diurnal tide has been known to be a source of the Earth's spin acceleration, and its magnitude is re-estimated by using an enhanced formulation and an up-dated empirical atmospheric S2 tide model. During the last twenty years, an unusual eastward drift of the Earth's pole has been observed. The change in the Earth's inertia tensor due to glacier mass redistribution is directly assessed, and the recent eastward movement of the pole is ascribed to this change. Furthermore, the associated changes in the length of day and UT1 are estimated.

Analysis on the Threshold Voltage of Nano-Channel MOSFET (나노채널 MOSFET의 문턱전압분석)

  • 정정수;김재홍;고석웅;이종인;정학기
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.6 no.1
    • /
    • pp.109-114
    • /
    • 2002
  • In this paper, we have presented the simulation results ah)ut threshold voltage for Si-based MOSFETs with channel length of nano scale. We simulated the Si-based n channel MOSFETs with gate lengths from 180 to 30 nm in accordance to the constant voltage scaling theory and the lateral scaling. These MOSFETs had the lightly doped drain(LDD) structure, which is used for the reduction of electric field magnitude and short channel effects at the drain region. The stronger electric field at this region is due to scaling down. We investigated and analyzed the threshold voltage of these devices. This analysis will provide insight into some applicable limitations at the ICs and used for basis data at VLSI.

Reduction of AgCl to Ag by $Na_2CO_3$ ($Na_2CO_3$에 의한 AgCl의 Ag 환원)

  • 박경호;노범식;손정수
    • Resources Recycling
    • /
    • v.5 no.1
    • /
    • pp.29-33
    • /
    • 1996
  • The cominnn plocesses lor rccoremg silver irom silvcr conlaincd waster are the lcachmg silver hy HNO;. the srlcctive precipilillion of sliver ion lo AgCl and thc rcduchon of Ag wrfh ;I proper reductant. In this sludy, thc reduction of AgCI lo Ag was invesllngated by using Na, CO, as a rcd\icta~lt. The variations wcic reaction time. ttmpcrarure thc amount of NalCO, . and the resulls %, ere analyzcd by using sialist~c:d tecl~niques such as the ]polynomial rcgressiun analysis and the response surh~ce method. More than Yh% Ag analyzed was rcduced 1rtm AgCI at 62UT. I hour ullder condillon of 2 stnlchio~nctric ratio of Na iCO, !AgCI.

  • PDF