• 제목/요약/키워드: Support width

검색결과 242건 처리시간 0.026초

The Most Massive Active Galactic Nuclei at 1

  • Jun, Hyunsung
    • 천문학회보
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    • 제42권2호
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    • pp.44.2-44.2
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    • 2017
  • We obtained near-infrared spectra of 26 SDSS quasars at 0.7${\sim}10^{{\wedge}{10}}M{\odot}$ to critically examine the systematic effects involved with their mass estimations. We find that active galactic nuclei (AGNs) heavier than $10^{{\wedge}{10}}M{\odot}$ often display double-peaked $H{\alpha}$ emission, extremely broad FeII complex emission around MgII, and highly blueshifted and broadened CIV emission. The weight of this evidence, combined with previous studies, cautions against the use of MBH values based on any emission line with a width over 8000 km/s. Also, the MBH estimations are not positively biased along the presence of ionized narrow line outflows, anisotropic radiation, or the use of line FWHM instead of ${\sigma}$ for our sample, and unbiased with variability, scatter in broad line equivalent width, or obscuration for general type-1 quasars. Removing the systematically uncertain MBH values, ${\sim}10^{{\wedge}{10}}M{\odot}$ BHs in 1${\sim}10^{{\wedge}{9.5}}M{\odot}$ BHs, although current observations support they are intrinsically most massive, and overmassive to the host's bulge mass.

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저열량탄의 휘발분과 산소농도가 Tar와 Soot의 발생률에 미치는 영향 (Effect of volatile matter and oxygen concentration on tar and soot yield depending on low calorific coal in Laminar Flow Reactor)

  • 정태용;김진호;이병화;송주헌;전충환
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
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    • pp.209-212
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    • 2012
  • This study was performed to analyze coal flames and measure tar and soot yields and structures of chars for two coals depending on the volatile content by the LFR(Laminar Flow Reactor) which can be applied to a variety of coal researches. The results show that volatile contents and oxygen concentration have significant influence on length and width of the soot cloud and it also indicate that the length and width of the cloud in condition of combustion decrease than those of pyrolysis atmosphere. Until the sampling height reach at 50 mm, the tar and soot yields of Berau (Sub-bituminous) coal contained relatively lots of volatile matters are less than those of Glencore A.P. (Bituminous) coal. On the other hand, tar and soot yields of Berau coal are higher than those of Glencore A.P. coal by reacted residual volatile matter. In addition, the images of samples obtained from the particle separation system of the sampling probe support for above results with the yields, and the pore development of char surface by devolatilization.

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초콜릿 소재의 3차원 프린터 개발에 관한 연구 (A Study on Development of Three-Dimensional Chocolate Printer)

  • 김규언;박근;이치범
    • 한국정밀공학회지
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    • 제34권4호
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    • pp.293-298
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    • 2017
  • In this study, we developed a 3D chocolate printer and studied the conditions needed for chocolate printing. Because chocolate is a mixture of cocoa mass, cocoa butter and sugar particles, its properties vary with temperature, and care is required in melting and extrusion. A chocolate supply unit is composed of a heating block and a syringe pump. It is integrated with a 3-axis linear robot. In order to be more accurate than the existing 3D chocolate printer is, the system was configured so that the printing line width became $430{\mu}m$. Printing performance was studied according to various parameters. The condition needed for printing lines with a stable width was discovered by the experimental design method and has been confirmed by a 2D line test. These 3D printing experiments showed that it was possible to build a 3D shape with an inclination angle of up to $45^{\circ}$ without support. Further, chocolate printing of a 3D shape has been successfully verified with the developed system.

Does apical root resection in endodontic microsurgery jeopardize the prosthodontic prognosis?

  • Cho, Sin-Yeon;Kim, Euiseong
    • Restorative Dentistry and Endodontics
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    • 제38권2호
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    • pp.59-64
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    • 2013
  • Apical surgery cuts off the apical root and the crown-to-root ratio becomes unfavorable. Crown-to-root ratio has been applied to periodontally compromised teeth. Apical root resection is a different matter from periodontal bone loss. The purpose of this paper is to review the validity of crown-to-root ratio in the apically resected teeth. Most roots have conical shape and the root surface area of coronal part is wider than apical part of the same length. Therefore loss of alveolar bone support from apical resection is much less than its linear length.The maximum stress from mastication concentrates on the cervical area and the minimum stress was found on the apical 1/3 area. Therefore apical root resection is not so harmful as periodontal bone loss. Osteotomy for apical resection reduces longitudinal width of the buccal bone and increases the risk of endo-perio communication which leads to failure. Endodontic microsurgery is able to realize 0 degree or shallow bevel and precise length of root resection, and minimize the longitudinal width of osteotomy. The crown-to-root ratio is not valid in evaluating the prosthodontic prognosis of the apically resected teeth. Accurate execution of endodontic microsurgery to preserve the buccal bone is essential to avoid endo-perio communication.

한국 재래닭의 부화 후 성장단계별 넙다리뼈와 정강뼈 성장에 관한 연구 (The growth stage study on the femur and tibia of Korean native chicken after hatching)

  • 태현진
    • 한국동물위생학회지
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    • 제38권3호
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    • pp.181-188
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    • 2015
  • Skeletal development of chicken has been widely discussed in industrial forums and various research reports. However, these studies were emphasis on the commercial chicken strains for improve egg and meat production whereas the skeletal quiet remains as a potential weak link related to facilitating in the physical support of heavier carcasses at ever younger ages. For that, the study of standardization of skeletal development is important but it was rarely reported in Korean native chicken (KNC). The study was investigated the skeletal characteristics of KNC for international standardization. We studied in KNC at 2, 14, 28, 42, 56, 70, 84, 98, 112, 126, 147, 168, 196, 224, 336 and 448 days after hatch (male and female, n=13 for each group). We measured the body weight (BW), and after sacrifice measured organs and remove muscle from femur & tibia and measured bone weight. Data were analyzed by ANOVA, Duncan test, correlation analysis and regression analysis of SAS 9.1. We analyzed the data of BW, femur & tibia and made growth curve also. The BW was significantly increased up to 147 days after hatch (male, $1,927.88{\pm}68.92g$; female, $1,456.00{\pm}50.11g$), and then increased gradually. At 336 days, these growth was stop (male, $2,467.00{\pm}42.84g$; female, $1,568.71{\pm}62.62g$). The growth of femur & tibia length and width was stop on 98~126 days after hatch. At 98 days, we measured the length and width of femur & tibia in male were $132.39{\pm}3.18mm$ & $25.98{\pm}0.59mm$ whereas in female at 112 days the length of femur & tibia was $116.40{\pm}1.55mm$ and at 126 days width was $21.41{\pm}0.38mm$. Our study suggests that the growth of male KNC was classified pre-puberty (0~98 days), puberty (98~336 days) and maturity (after 336 days), meanwhile female was shown similar trend however puberty period of KNC was 112 or 126 days after hatch.

스펙트럼 군집화에서 블록 대각 형태의 유사도 행렬 구성 (Magnifying Block Diagonal Structure for Spectral Clustering)

  • 허경용;김광백;우영운
    • 한국멀티미디어학회논문지
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    • 제11권9호
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    • pp.1302-1309
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    • 2008
  • K-means나 퍼지 군집화와 같은 전통적인 군집화 기법들이 원형(prototype)을 기반으로 하고 볼록한 형태의 집단들에 적합한 반면, 스펙트럼 군집화(spectral clustering)는 국부적인 유사성을 기반으로 전역적인 집단을 찾아내는 기법으로 오목한 형태의 집단들에도 적용할 수 있어 커널을 기반으로 하는 SVM과 더불어 각광을 받고 있다. 하지만 SVM이 그러하듯이 스펙트럼 군집화에서도 커널의 폭은 성능에 지대한 영향을 끼치는 요인으로, 이를 결정하기 위한 다양한 방법이 시도되었지만 여전히 휴리스틱에 의존하는 실정이다. 이 논문에서는 유사도 행렬이 보다 명백한 블록 대각 형태를 가지도록 하기 위해 국부적인 커널의 폭을 거리 히스토그램을 바탕으로 적응적으로 결정하는 방법을 제시한다. 제안한 방법은 스펙트럼 군집화에 사용되는 유사도 행렬(affinity matrix)이 블록 형태의 대각 행렬을 이룰 때 이상적인 결과를 낸다는 사실에 기반하고 있으며, 이를 위해서 전통적인 유클리디안 거리와 무작위 행보 거리(random walk distance)를 함께 사용한다. 제안한 방법은 기존의 방법들에서 사용하는 유사도 행렬에 비해 명확한 블록 대각 행렬을 나타내고 있음을 실험 결과를 통해 확인할 수 있다.

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Evaluation of accuracies of genomic predictions for body conformation traits in Korean Holstein

  • Md Azizul Haque;Mohammad Zahangir Alam;Asif Iqbal;Yun Mi Lee;Chang Gwon Dang;Jong Joo Kim
    • Animal Bioscience
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    • 제37권4호
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    • pp.555-566
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    • 2024
  • Objective: This study aimed to assess the genetic parameters and accuracy of genomic predictions for twenty-four linear body conformation traits and overall conformation scores in Korean Holstein dairy cows. Methods: A dataset of 2,206 Korean Holsteins was collected, and genotyping was performed using the Illumina Bovine 50K single nucleotide polymorphism (SNP) chip. The traits investigated included body traits (stature, height at front end, chest width, body depth, angularity, body condition score, and locomotion), rump traits (rump angle, rump width, and loin strength), feet and leg traits (rear leg set, rear leg rear view, foot angle, heel depth, and bone quality), udder traits (udder depth, udder texture, udder support, fore udder attachment, front teat placement, front teat length, rear udder height, rear udder width, and rear teat placement), and overall conformation score. Accuracy of genomic predictions was assessed using the single-trait animal model genomic best linear unbiased prediction method implemented in the ASReml-SA v4.2 software. Results: Heritability estimates ranged from 0.10 to 0.50 for body traits, 0.21 to 0.35 for rump traits, 0.13 to 0.29 for feet and leg traits, and 0.05 to 0.46 for udder traits. Rump traits exhibited the highest average heritability (0.29), while feet and leg traits had the lowest estimates (0.21). Accuracy of genomic predictions varied among the twenty-four linear body conformation traits, ranging from 0.26 to 0.49. The heritability and prediction accuracy of genomic estimated breeding value (GEBV) for the overall conformation score were 0.45 and 0.46, respectively. The GEBVs for body conformation traits in Korean Holstein cows had low accuracy, falling below the 50% threshold. Conclusion: The limited response to selection for body conformation traits in Korean Holsteins may be attributed to both the low heritability of these traits and the lower accuracy estimates for GEBVs. Further research is needed to enhance the accuracy of GEBVs and improve the selection response for these traits.

A new bite block for panoramic radiographs of anterior edentulous patients: A technical report

  • Park, Jong-Woong;Symkhampha, Khanthaly;Huh, Kyung-Hoe;Yi, Won-Jin;Heo, Min-Suk;Lee, Sam-Sun;Choi, Soon-Chul
    • Imaging Science in Dentistry
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    • 제45권2호
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    • pp.117-122
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    • 2015
  • Purpose: Panoramic radiographs taken using conventional chin-support devices have often presented problems with positioning accuracy and reproducibility. The aim of this report was to propose a new bite block for panoramic radiographs of anterior edentulous patients that better addresses these two issues. Materials and Methods: A new panoramic radiography bite block similar to the bite block for dentulous patients was developed to enable proper positioning stability for edentulous patients. The new bite block was designed and implemented in light of previous studies. The height of the new bite block was 18 mm and to compensate for the horizontal edentulous space, its horizontal width was 7 mm. The panoramic radiographs using the new bite block were compared with those using the conventional chin-support device. Results: Panoramic radiographs taken with the new bite block showed better stability and bilateral symmetry than those taken with the conventional chin-support device. Patients also showed less movement and more stable positioning during panoramic radiography with the new bite block. Conclusion: Conventional errors in panoramic radiographs of edentulous patients could be caused by unreliability of the chin-support device. The newly proposed bite block for panoramic radiographs of edentulous patients showed better reliability. Further study is required to evaluate the image quality and reproducibility of images with the new bite block.

Out-of-plane buckling and bracing requirement in double-angle trusses

  • Chen, Shaofan;Su, Mingzhou
    • Steel and Composite Structures
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    • 제3권4호
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    • pp.261-275
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    • 2003
  • Truss members built-up with double angles back-to-back have monosymmetric cross-section and twisting always accompanies flexion upon the onset of buckling about the axis of symmetry. Approximate formulae for calculating the buckling capacity are presented in this paper for routine design purpose. For a member susceptible only to flexural buckling, its optimal cross-section should consist of slender plate elements so as to get larger radius of gyration. But, occurrence of twisting changes the situation owing to the weakness of thin plates in resisting torsion. Criteria for limiting the leg slenderness are discussed herein. Truss web members in compression are usually considered as hinged at both ends for out-of-plane buckling. In case one (or both) end of member is not supported laterally by bracing member, its adjoining members have to provide an elastic support of adequate stiffness in order not to underdesign the member. The stiffness provided by either compression or tension chords in different cases is analyzed, and the effect of initial crookedness of compression chord is taken into account. Formulae are presented to compute the required stiffness of chord member and to determine the effective length factor for inadequately constrained compressive diagonals.

병렬프로세서를 활용한 레이더 신호의 식별 (An Identification Method of Radar Signals using Parallel Processor)

  • 김관태;주영관;박상환;전중남
    • 전자공학회논문지
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    • 제54권4호
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    • pp.75-80
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    • 2017
  • 전자전지원 시스템(Electronic Warfare Support System)은 레이더 신호의 식별을 위해 수집한 신호의 주파수, 펄스폭, 펄스반복주기(PRI, Pulse Repetition Interval)등의 정보를 분석한 후 기존의 알려진 레이더 정보와 비교한다. 기존의 연구는 두 가지 단점이 있다. 첫 번째 단점은 기존의 알려진 레이더 정보를 마지막 비교단계에서만 비교한다는 점이다. 두 번째 단점은 PRI를 계산하기 위해 많은 연산이 필요하다는 점이다. 본 논문에서는 사전에 알려진 레이더 정보를 초기단계에서 활용하여 PRI를 계산하지 않고 수집된 신호에 미리 알고 있는 레이더 신호의 존재 여부를 식별하는 방법을 제안한다.