• Title/Summary/Keyword: source region

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Catalog of the Paα-emitting Sources observed in the Carina Region

  • Kim, Il-Joong;Pyo, Jeonghyun;Jeong, Woong-Seob
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.2
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    • pp.66.2-66.2
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    • 2021
  • We list up the Paα-emitting sources observed in the Carina Region (l = 276°-296°) using the MIRIS Paα Galactic Plane Survey data. A total of 201 sources are cataloged. Out of them, 118 sources are coincident with those in the WISE H II region catalog. 52 H II region candidates are newly confirmed as definite H II regions by detecting the Paα recombination lines. For the remaining 83 sources, we search the corresponding objects in the SIMBAD database. 26 point-like sources are associated with planetary nebulae or emission-line stars (such as Wolf-Rayet and Blue supergiant stars). Also, we carry out aperture photometry to measure Paα fluxes for the sources that show circular features without overlapping with other bright sources. For the whole Galactic Plane, the complete Paα-emitting source catalog is in progress.

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A SOURCE EXTRACTION METHOD FOR THE AKARI MID-IR FAINT SOURCE CATALOGUE

  • Nakamichi, Keichiro;Ishihara, Daisuke;Kaneda, Hidehiro;Oyabu, Shinki;Kondo, Toru;Amatsutsu, Tomoya;Sano, Hidetoshi;Onaka, Takashi
    • Publications of The Korean Astronomical Society
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    • v.32 no.1
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    • pp.29-31
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    • 2017
  • We plan to produce a faint source catalogue from the AKARI mid-infrared (IR) all-sky diffuse maps. In the publicly-available AKARI mid-IR point source catalogue (PSC), sources were extracted from single-scan images, and confirmed by using the other scan images. By stacking multiple scan images, we can detect fainter sources which are not listed in the PSC. We optimized the source extraction process using a $6^{\circ}{\times}6^{\circ}C$ area around the star-forming region, Cepheus B. Then, we divided the all-sky data into three seasonal images, and checked the positions and the fluxes of the detected sources on the images. As a result, our new source extraction method works well; 90% of the sources are also identified in the WISE catalogue. In this method, we obtain the detection limit twice deeper than that of the PSC. The number of sources increases by a factor of 2, as compared with the PSC.

Avalanche Hot Source Method for Separated Extraction of Parasitic Source and Drain Resistances in Single Metal-Oxide-Semiconductor Field Effect Transistors

  • Baek, Seok-Cheon;Bae, Hag-Youl;Kim, Dae-Hwan;Kim, Dong-Myong
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.12 no.1
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    • pp.46-52
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    • 2012
  • Separate extraction of source ($R_S$) and drain ($R_D$) resistances caused by process, layout variations and long term degradation is very important in modeling and characterization of MOSFETs. In this work, we propose "Avalanche Hot-Source Method (AHSM)" for simple separated extraction of $R_S$ and $R_D$ in a single device. In AHSM, the high field region near the drain works as a new source for abundant carriers governing the current-voltage relationship in the MOSFET at high drain bias. We applied AHSM to n-channel MOSFETs as single-finger type with different channel width/length (W/L) combinations and verified its usefulness in the extraction of $R_S$ and $R_D$. We also confirmed that there is a negligible drift in the threshold voltage ($V_T$) and the subthreshold slope (SSW) even after application of the method to devices under practical conditions.

Improvement of ESD Protection Performance of High Voltage Operating EDNMOS Device with Double Polarity Source (DPS) Structure (DPS(Double Polarity Source) 구조를 갖는 고전압 동작용 EDNMOS 소자의 정전기 보호 성능 개선)

  • Seo, Yong-Jin;Yang, Jun-Won
    • Journal of Satellite, Information and Communications
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    • v.9 no.2
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    • pp.12-17
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    • 2014
  • In this paper, modified EDNMOS device with DPS (double polarity source) structure are suggested to realize stable and robust ESD (electrostatic discharge) protection performance of high voltage operating microchip. This DPS structure inserts the P+ diffusion layer on N+ source side, which in intended to block lateral extension of the electron rich region from N+ source side. Based on our simulation results, the inserted P+ diffusion layer effectively prevents the formation of deep electron channeling induced by high electron injection. As a result, our proposed DPS_EDNMOS devices could overcome the double snapback effect of conventional Std_EDNMOS device.

Numerical Analysis on Biogenic Emission Sources Contributing to Urban Ozone Concentration in Osaka, Japan

  • Nishimura, Hiroshi;Shimadera, Hikari;Kondo, Akira;Akiyama, Kazuyo;Inoue, Yoshio
    • Asian Journal of Atmospheric Environment
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    • v.9 no.4
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    • pp.259-271
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    • 2015
  • This study conducted analyses on biogenic volatile organic compounds (BVOC) emission sources contributing to urban ozone ($O_3$) concentration in Osaka Prefecture, Japan in summer 2010 by using the Weather Research and Forecasting model (WRF) version 3.5.1 and the Community Multiscale Air Quality model (CMAQ) version 5.0.1. This prefecture is characterized by highly urbanized area with small forest area. The contributions of source regions surrounding Osaka were estimated by comparing the baseline case and zero-out cases for BVOC emissions from each source region. The zero-out emission runs showed that the BVOC emissions substantially contributed to urban $O_3$ concentration in Osaka (10.3 ppb: 15.9% of mean daily maximum 1-h $O_3$ concentration) with day-by-day variations of contributing source regions, which were qualitatively explained by backward trajectory analyses. Although $O_3$ concentrations were especially high on 23 July and 2 August 2010, the contribution of BVOC on 23 July (35.4 ppb: 25.6% of daily maximum $O_3$) was much larger than that on 2 August (20.9 ppb: 14.2% of daily maximum $O_3$). To investigate this difference, additional zero-out cases for anthropogenic VOC (AVOC) emissions from Osaka and for VOC emissions on the target days were performed. On 23 July, the urban $O_3$ concentration in Osaka was dominantly increased by the transport from the northwestern region outside Osaka with large contribution of $O_3$ that was produced through BVOC reactions by the day before and was retained over the nocturnal boundary layer. On 2 August, the concentration was dominantly increased by the local photochemical production inside Osaka under weak wind condition with the particularly large contribution of AVOC emitted from Osaka on the day.

Efficient Sound Source Localization System Using Angle Division (영역 분할을 이용한 효율적인 음원 위치 추정 시스템)

  • Kim, Yong-Eun;Cho, Su-Hyun;Chung, Jin-Gyun
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.2
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    • pp.114-119
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    • 2009
  • Sound source localization systems in service robot applications estimate the direction of a human voice. Time delay information obtained from a few separate microphones is widely used for the estimation of the sound direction. Correlation is computed in order to calculate the time delay between two signals. Inverse cosine is used when the position of the maximum correlation value is converted to an angle. Because of nonlinear characteristic of inverse cosine, the accuracy of the computed angle is varied depending on the position of the specific sound source. In this paper, we propose an efficient sound source localization system using angle division. By the proposed approach, the region from $0^{\circ}$ to $180^{\circ}$ is divided into three regions and we consider only one of the three regions. Thus considerable amount of computation time is saved. Also, the accuracy of the computed angle is improved since the selected region corresponds to the linear part of the inverse cosine function. By simulations, it is shown that the error of the proposed algorithm is only 31% of that of the conventional a roach.

Detection of Fatigue Damage in Aluminum Thin Plates with Rivet Holes by Acoustic Emission (리벳 구멍을 가진 알루미늄 박판구조의 피로손상 탐지를 위한 음향방출의 활용)

  • Kim, Jung-Chan;Kim, Sung-Jin;Kwon, Oh-Yang
    • Journal of the Korean Society for Nondestructive Testing
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    • v.23 no.3
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    • pp.246-253
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    • 2003
  • The initiation and growth of short fatigue cracks in the simulated aircraft structure with a series of rivet holes was detected by acoustic emission (AE). The location and the size of short tracks were determined by AE source location techniques and the measurement with traveling microscope. AE events increased intermittently with the initiation and growth of short cracks to form a stepwise increment curve of cumulative AE events. For the precise determination of AE source locations, a region-of-interest (ROI) was set around the rivet holes based on the plastic zone size in fracture mechanics. Since the signal-to-noise ratio (SNR) was very low at this early stage of fatigue cracks, the accuracy of source location was also enhanced by the wavelet transform do-noising. In practice, the majority of AE signals detected within the ROI appeared to be noise from various origins. The results showed that the effort of structural geometry and SNR should be closely taken into consideration for the accurate evaluation of fatigue damage in the structure.

The Hand Region Acquistion System for Gesture-based Interface (제스처 기반 인터페이스를 위한 손영역 획득 시스템)

  • 양선옥;고일주;최형일
    • Journal of the Korean Institute of Intelligent Systems
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    • v.8 no.4
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    • pp.43-52
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    • 1998
  • We extract a hand region by using color information, which is an important feature for human vision to distinguish objects. Because pixel values in images are changed according to the luminance and lighting source, it is difficult to extract a hand region exactly without previous knowledge. We generate a hand skin model at learning stage, and extract a hand region from images by using the model. We also use a Kalman filter to consider changes of pixel values in a hand skin model. A Kalman filter restricts a search area for extracting a hand region at next frame also. The validity of the proposed method is proved by implementing the hand-region acquisition module.

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PROPERTIES OF THE MOLECULAR CLUMP AND THE ASSOCIATED ULTRACOMPACT H II REGION IN THE GAS SHELL OF THE EXPANDING H II REGION SH 2-104

  • Minh, Young Chol;Kim, Kee-Tae;Yan, Chi-Hung;Park, Yong-Sun;Lee, Seokho;Lal, Dharam Vil;Hasegawa, Tatsuhiko;Zhang, X.Z.;Kuan, Yi-Jeng
    • Journal of The Korean Astronomical Society
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    • v.47 no.5
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    • pp.179-185
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    • 2014
  • We study the physical and chemical properties of the molecular clump hosting a young stellar cluster, IRAS 20160+3636, which is believed to have formed via the "collect and collapse" process. Physical parameters of the UC H II region associated with the embedded cluster are measured from the radio continuum observations. This source is found to be a typical Galactic UC H II region, with a B0.5 type exciting star, if it is ionized by a single star. We derive a CN/HCN abundance ratio larger than 1 over this region, which may suggest that this clump is being affected by the UV radiation from the H II region.

Improvement on Management of Non-point Source Pollution for Reasonable Implementation of TMDL - Focusing on Selection of Non-point Source Pollution Management Region and Management of Non-point Source Pollutant - (수질오염총량관리제의 합리적인 시행을 위한 비점오염원관리 개선방안 - 비점오염원 관리지역 선정 및 비점오염물질 관리를 중심으로 -)

  • Yi, Sang-Jin;Kim, Young-Il
    • Journal of Korean Society of Environmental Engineers
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    • v.36 no.10
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    • pp.719-723
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    • 2014
  • For effective implementation of total maximum daily load (TMDL), this study presented the improving plans of non-point source pollution management including the classification of non-point source pollution, calculation of non-point source pollution load (generated, discharged), selection of non-point source pollution management regions and management of non-point source pollutant. First of all, the definition of point source pollution and non-point source pollution based on the legal and scientific viewpoint should be precisely classified and managed. Especially, the forest, grassland and river without occurrence of environmental damage by activity of business and human should be separately classified natural background pollutants. The unit for generated and discharged non-point source pollution should be preferentially changed according to actual condition of watershed. The calculation methods of generated and discharged non-point source pollution should be corrected consideration on the amount and duration of rainfall. While the TMDL is implemented, non-point source pollution management regions should be selected in the watersheds exceed the targeted water quality standards by the rainfall. The non-point source pollution management regions should be selected in the minimal regions where have high values of discharged non-point source pollution density in the urban area, farmland and site area except forest, grassland in the whole watershed. The non-point source pollutant treatment facilities, which take into consideration non-point source pollution load per unit area, duration of the excess concentration, realizable possibility of treatment, effectiveness of treatment cost versus point source pollutant, should be established in the regions with a large generated non-point source pollution load and a high concentration of water quality exceed the targeted water quality standards by the rainfall.