• Title/Summary/Keyword: comparing region

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TRAO Survey of Nearby Filamentary Molecular Clouds, the Universal Nursery of Stars (TRAO FUNS). III. Dynamics of filaments in different star forming environments

  • Chung, Eun Jung;Kim, Shinyoung;Yoo, Hyunju;Lee, Chang Won
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.69.2-69.2
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    • 2019
  • Recent high resolution IR observations reveal that molecular clouds are filamentary and such a structure is ubiquitous over various star-forming environments, and it is clear that filaments play a crucial role in the formation of cores and stars. However, the formation process of dense cores in the filaments are still unknown. To investigate this issue in detail, we have carried out TRAO FUNS (TRAO survey of nearby Filamentary molecular clouds, the Universal Nursery of Stars) toward various star forming filamentary molecular clouds. In this presentation, we will report the first look results of filaments and dense cores in MCLD 123.5+24.9 and IC 5146, which are known as a quiescent, non-star-forming region and an active, high-mass star forming region, respectively. By comparing the kinematic properties of filaments and dense cores in different star forming environments, we verified the formation scenario of filaments and dense core, i.e., gravoturbulent fragmentation via supersonic motions.

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Analysis of the Manufacturing Process using Multiple Comparison Procedure (다중비교 절차를 이용한 제조공정의 분석)

  • 최봉욱;김광섭
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.20 no.44
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    • pp.333-341
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    • 1997
  • The purpose of this paper is to compare the manufacturing process with random covariate using multiple comparison procedure. The methodology that compares each manufacturing process by inspecting the number of nonconforming items out of k-treatment, has serveral limitations and problems according to the method and contect of the analysis. The proper way of analysis, therefore, could be obtained by the multiple comparison procedure of simultaneous confidence region of variance components. Effections that affect a manufactuing process may be predictive of responce to treatments are called covariates. In the study of comparing several treatments, prsense of covariate may bias the estimates of treatment effects.

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DUST SHELL MODELS FOR LOW MASS-LOSS RATE OXYGEN-RICH AGB STARS

  • SUH KYUNG-WON
    • Journal of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.267-270
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    • 2005
  • We investigate the spectral energy distributions (SEDs) of low mass-loss rate O-rich asymptotic giant branch (AGB) stars using the infrared observational data including the Infrared Space Observatory (ISO) data. Comparing the results of detailed radiative transfer model calculations with observations, we find that the dust formation temperature is much lower than 1000 K for standard dust shell models. We find that the superwind model with a density-enhanced region can be a possible alternative dust shell model for LMOA stars.

Theoretical recognition thresholding decision of Han-geul character in Rapid Transform region (R-변환 영역에서 한글 문자의 인식한계 결정)

  • Chin, Yong-Ohk
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.936-940
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    • 1987
  • This paper describes the recognition boundary of Hangeul character to interpret variance factor in accordance with various combination. When the recognition algorithm based on comparing the MSE value with the one of the standard pattern in $16{\times}16$ images is performed, we come to a conclusion that we have towe must make a decision MSE value above 34 in order to achive theve recognition rate larger than 90%. Also we understand that varing component coordinates method based on statistical process of each character pattern is preferred.

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Simulation of Optimum Irrigation Water of Upland Crops by Evapotranspiration Calculation Methods (증발산량 산정기법에 따른 밭작물의 적정 관개량 모의)

  • Kim, Sun-Joo;Lee, Joo-Yong;Kim, Phil-Shik
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2003.10a
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    • pp.271-274
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    • 2003
  • The objectives of this study are for finding an optimal calculation method comparing observed evapotranspiration with calculated evapotranspiration by Blaney-Criddle, Penman and Penman-Monteith method which are used in many place of Korea. And after appling optimal calculation method, optimal irrigation is presented through calculation of effective rainfall and requirement water considering characteristics of region, crop and soil.

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A Unified Channel Thermal Noise Model for Short Channel MOS Transistors

  • Yu, Sang Dae
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.13 no.3
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    • pp.213-223
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    • 2013
  • A unified channel thermal noise model valid in all operation regions is presented for short channel MOS transistors. It is based on smooth interpolation between weak and strong inversion models and consistent physical model including velocity saturation, channel length modulation, and carrier heating. From testing for noise benchmark and comparing with published noise data, it is shown that the proposed noise model could be useful in simulating the MOSFET channel thermal noise in all operation regions.

A Graphical Method for Evaluating Mixture Designs with respect to the Slope

  • Jang, Dae-Heung;Na, Ho-Jun
    • Journal of Korean Society for Quality Management
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    • v.23 no.2
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    • pp.68-79
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    • 1995
  • Good estimation of the slopes of the mixture response function may be important as well as estimation of mean mixture response. It is possible to evaluate and compare several mixture designs with respect to the slope. A graphical method is proposed that allows us to evaluate a given design's support for the fitted model in terms of slope variance. We can plot variances of slopes along Cox direction according to existence of restriction of simplex region when comparing several different mixture designs.

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Application of Algebraic Stress Model to the Calculation of the Viscous Flow around a Ship (대수응력 난류 모델의 선체주위 점성유동해석에의 적용)

  • Oh K. J.;Choi J. E.
    • Journal of computational fluids engineering
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    • v.5 no.1
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    • pp.22-26
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    • 2000
  • The flow around a ship is complex, especially, at the stern region of a full ship, where highly curved streamlines, hook-shaped iso-velocity contours, and strong secondary flow exist. To resolve this complex flow, an Algebraic Stress Model(ASM) is applied. The calculations are performed for the HSVA Tanker. The results are improved comparing with those of standard k-ε turbulence model, but still show a little difference from the experiments.

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Effective Annealing and Crystallization of Si film for Advanced TFT System

  • Noguchi, Takashi
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.254-257
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    • 2009
  • The crystallization and activated annealing effect of Si films using an excimer laser and a new CW blue laser are described comparing with furnace annealing (SPC) for the application of advanced TFTs and future applications. Currently, pulsed ELA is used extensively as a LTPS process on glass substrates as the efficiency is high in UV region for thin Si film of 40- 60 nm thickness. ELA enables extremely low resistivity for both n- and p-typed Si films. On the other hand, CW BLDA enables the smooth Si surface having arbitral grains from micro-grains to anisotropic huge grain structure only controlling its power density.

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THE EFFECT OF DOPANT OUTDIFFUSION ON THE NEUTRAL BASE RECOMBINATION CURRENT IN Si/SiGe/Si HETEROJUNCTION BIPOLAR TRANSISTORS

  • Ryum, Byung-R.;Kim, Sung-Ihl
    • ETRI Journal
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    • v.15 no.3
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    • pp.61-69
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    • 1994
  • A new analytical model for the base current of Si/SiGe/Si heterojunction bipolar transistors(HBTs) has been developed. This model includes the hole injection current from the base to the emitter, and the recombination components in the space charge region(SCR) and the neutral base. Distinctly different from other models, this model includes the following effects on each base current component by using the boundary condition of the excess minority carrier concentration at SCR boundaries: the first is the effect of the parasitic potential barrier which is formed at the Si/SiGe collector-base heterojunction due to the dopant outdiffusion from the SiGe base to the adjacent Si collector, and the second is the Ge composition grading effect. The effectiveness of this model is confirmed by comparing the calculated result with the measured plot of the base current vs. the collector-base bias voltage for the ungraded HBT. The decreasing base current with the increasing the collector-base reverse bias voltage is successfully explained by this model without assuming the short-lifetime region close to the SiGe/Si collector-base junction, where a complete absence of dislocations is confirmed by transmission electron microscopy (TEM)[1].The recombination component in the neutral base region is shown to dominate other components even for HBTs with a thin base, due to the increased carrier storage in the vicinity of the parasitic potential barrier at collector-base heterojunction.

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