• Title/Summary/Keyword: Dark current

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Mapping the Polarization of the Radio-Loud Lyman Alpha Nebula B3 J2330+3927

  • Yang, Yujin;You, Chang;Zabludoff, Ann;Smith, Paul;Jannuzi, Buell;Prescott, Moire
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.2
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    • pp.28.3-29
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    • 2015
  • $Ly{\alpha}$ nebulae, or "$Ly{\alpha}$ blobs", are extended (~100 kpc), bright (L[$Ly{\alpha}$] ~ 1044 erg/s) clouds of $Ly{\alpha}$-emitting gas. The origin of the $Ly{\alpha}$ emission remains unknown, but recent theoretical work suggests that measuring the polarization could discriminate among powering mechanisms. we will discuss current status of $Ly{\alpha}$ polarization observations at high-redshift and our on-going survey program. We will present the first narrow-band, imaging polarimetry of a $Ly{\alpha}$ blob, B3 J2330+3927 at z=3.09, with an embedded, radio-loud AGN (C. You et al. in prep.). The AGN lies near the blob's $Ly{\alpha}$ emission peak and its radio lobes align roughly with the blob's semi-major axis. With the SPOL polarimeter on the MMT telescope, we map the polarization in a grid of circular apertures of radius 0.6" (4.4 kpc), detecting a significant (>$2{\sigma}$) polarization fraction P% in 10 apertures and achieving strong upper-limits (as low as 2%) elsewhere. The degree of the polarization map increases from P% ~ 5% at ~5 kpc from the blob center to ~20% at the outer part (~30 kpc). The detections are distributed asymmetrically, roughly along the blob's major axis. The polarization angles (${\Theta}$) are mostly perpendicular to this axis. These results are consistent with the picture that $Ly{\alpha}$ photons produced at the AGN (or the host galaxy) are resonantly scattered away from the center. Higher polarization fraction on the radio jet suggests that the gas is more optically thin along the jet than the off-axis region.

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Compositional analysis by NIRS diode array instrumentation on forage harvesters

  • Andreashaeusler, Michael Rode;Christian, Paul
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1619-1619
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    • 2001
  • Ourwork aims to assess the content of dry matter, protein, cell wall parameters and water soluble carbohydrates in forages without having to handle samples, transport them to a laboratory, dry, grind and chemically analyze them. for this purpose, the concept of fresh forage analysis under field conditions by means of compact integrated NIRS InGaAs-diode array instruments on small plot harvesters is being evaluated for plant breeding trials. This work was performed with the world first commercial experimental forage plot harvester equipped with a NIRS module for the collection, compression, and scanning of forage samples (including automatic referencing and dark current measure ments). It was used for harvesting and analyzing a number of typical forage grass and forage legume plot trials. After NIRS measurements in the field each sample was again analyzed in the laboratory by means of a conventional grating spectrometer equipped with Si-and PbS-detectors. Conventional laboratory analysis of the samples was restricted to dry matter (DM) content by means of oven drying at 105. Routine chemometric procedures were then employed to assess the comparative accuracy and precision of the DM assessments in the spectral range between 950 and 1650nm by the NIRS diode array as well as by the conventional NIRS scanning instrument. The results of this study confirmed that the type of NIRS diode array instrument employed here functioned well even in rugged field operations. further refinements proved to be necessary for optimizing the automatic filling of the sample compartment to adjust for the wide variation in forage material under conditions of extremely low or high harvest yields. The error achieved in calibrating the apparatus for forages of typical DM content proved to be satisfactory (SECV < 1.0). Possibly as a consequence of higher sampling errors, its performance in atypical forages with elevated DM contents was less satisfactory. The error level obtained on the conventional grating NIR spectrometer was similar to that of the diode array instrument for both types of forage.

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Image System Using Dual Energy Detector (이중 에너지 검출기를 이용한 영상 시스템)

  • Yeo, Hwa-Yeon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.9
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    • pp.3517-3523
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    • 2010
  • Single exposure dual X-ray imaging can be used to separate soft and dense-material images for medical and industrial applications. This study keep focusing baggage inspection system(BIS) specifically. New detector modules for single exposure dual X-ray imaging are consisted of low energy detector (LED) and high energy detector (HED). First, the optimized thickness of copper filter coupled HED to separate low energy and high energy was simulated by the given X-ray energy (140 kVp, 1 mA) using Monte Carlo simulation codes, MCNPX. So as a result of simulation, the copper filter thickness is 0.7 mm. For the design of PIN photodiode, ATLAS device simulation tool was used. 16 channels PIN photodiode of 1.5 mm ${\times}$ 3.2 mm for Dual X-ray imaging detector was fabricated in the process of ETRI. And its dark current and quantum efficiency, terminal capacitance were measured. It was proven that the Lanex Fast B coupled HED were a sufficient candidate to replace the CsI(Tl) commerced in dual X-ray system, since these give a strong signal, overcoming system noise. Finally dual X-ray image was acquired through correction of the LED X-ray Image and the HED X-ray Image.

Primary Malignant Melanoma in the Pineal Region

  • Park, Jae-Hyun;Hong, Yong-Kil
    • Journal of Korean Neurosurgical Society
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    • v.56 no.6
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    • pp.504-508
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    • 2014
  • A 59-year-old male patient had 5-month history of gait disturbance and memory impairment. His initial brain computed tomography scan showed $3.5{\times}2.8cm$ sized mass with high density in the pineal region. The tumor was hypointense on T2 weighted magnetic resonance images and hyperintense on T1 weighted magnetic resonance images with heterogenous enhancement of central portion. The tumor was totally removed via the occipital transtentorial approach. Black mass was observed in the operation field, and after surgery, histopathological examination confirmed the diagnosis of malignant melanoma. Whole spine magnetic resonance images and whole body 18-fluoro-deoxyglucose positron emission tomography could not demonstrate the primary site of this melanoma. Scrupulous physical examination of his skin and mucosa was done and dark pigmented lesion on his left leg was found, but additional studies including magnetic resonance images and skin biopsy showed negative finding. As a result, final diagnosis of primary pineal malignant melanoma was made. He underwent treatment with the whole brain radiotherapy and extended local boost irradiation without chemotherapy. His preoperative symptoms were disappeared, and no other specific neurological deficits were founded. His follow-up image studies showed no recurrence or distant metastasis until 26 weeks after surgery. Primary pineal malignant melanomas are extremely rare intracranial tumors, and only 17 cases have been reported since 1899. The most recent case report showed favorable outcome by subtotal tumor resection followed by whole brain and extended local irradiation without chemotherapy. Our case is another result to prove that total tumor resection with radiotherapy can be the current optimal treatment for primary malignant melanoma in the pineal region.

Sclerosing Meningioma : Radiological and Clinical Characteristics of 21 Cases

  • Kang, Ho;Kim, Jin Wook;Se, Young-Bem;Dho, Yun-Sik;Choi, Seung Hong;Park, Sung-Hye
    • Journal of Korean Neurosurgical Society
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    • v.59 no.6
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    • pp.584-589
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    • 2016
  • Objective : A rare subtype of meningioma, sclerosing meningioma is not included in the current World Health Organization classification of meningiomas and is classified into the category of other morphological variation subtypes. Sclerosing meningioma is often misdiagnosed to other non-benign meningioma or malignant neoplasm, so it is important to diagnose sclerosing type correctly. We analyzed the radiological and clinical characteristics of a series of sclerosing meningiomas. Methods : Twenty-one patients who underwent surgery in one institute with a histopathologically proven sclerosing meningioma were included from 2006 to 2014. Eighteen tumors were diagnosed as a pure sclerosing-type meningioma, and 3 as mixed type. Magnetic resonance image was taken for all patients including contrast enhancement image. Computed tomography (CT) scan was taken for 16 patients. One neuroradiologist and 1 neurosurgeon reviewed all images retrospectively. Results : In the all 16 patients with preoperative CT images, higher attenuation was observed in the meningioma than in the brain parenchyma, and calcification was observed in 11 (69%). In 15 of the 21 patients (71%), a distinctive very low signal intensity appeared as a dark color in T2-weighted images. Nine of these 15 tumors (60%) exhibited heterogeneous enhancement, and 6 (40%) exhibited homogeneous enhancement that was unlike the homogeneous enhancing pattern shown by conventional meningiomas. Ten patients had a clear tumor margin without peritumoral edema. Conclusion : Although these peculiar radiological characteristics are not unique to sclerosing meningioma, we believe that they are distinctive features that may be helpful for distinguishing sclerosing meningioma from other subtypes.

Fabrication and characterization of CdS photoconductive cell by the print/sintering method (인쇄/소결 방법에 의한 CdS 광전도 셀 제작과 특성)

  • Jeong, Tae-Soo;Kim, Taek-Sung;Jeong, Cheol-Hoon;Lee, Hoon;Shin, Yeong-Jin;Hong, Kwang-Joon;Yu, Pyeong-Yeol
    • Journal of Sensor Science and Technology
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    • v.7 no.5
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    • pp.350-355
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    • 1998
  • We fabricated a photoconductive cell made of polycrystalline CdS thick film which has high photo-sensitivity using a print/sintering method. The resultant grain size is about $4\;{\mu}m$. When $CuCl_2$ of 0.06 to 0.12 mg is added, the sensitivity and the ratio of photocurrent to dark current are 0.8 and $10^5$, respectively. The response wavelength is 511 nm. The rise and decay response times are 50 and 20 ms, respectively. In addition, the maximum power dissipation is beyond 80mW. We noticed that the addition of $CuCl_2$ between 0.06 and 0.12 mg to 1g of CdS results in a reliable formation of photoconductive sensor.

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The Characteristics of Achromatic & Chromatic Color Coordination In Current Women's Fashion -Centered on the Collections of Paris, Milan, New York, London - (현대 패션에 나타난 무채색과 유채색 코디네이션 특성 - 파리, 밀란, 뉴욕, 런던 컬렉션 중심으로 -)

  • Kwon, Hae-Sook
    • Journal of Fashion Business
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    • v.12 no.4
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    • pp.73-87
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    • 2008
  • The main objective of this research was to investigate the characteristics of achromatic & chromatic color coordination of contemporary female fashion by reviewing 'pre-a-porter Collections' of four collections (i. e. cities) - Paris, Milan, New York, London - from the periods of 2002 S/S to 2006/7 A/W. The data was collected by reviewing 'pre-a-porter Collections' magazine and total 677 observations were made. Statistical analysis of frequency and also qualitative interpretation of achromatic & chromatic color coordination characteristics were completed. The main findings were; (1) The achromatic & chromatic color coordination was identified as one of most used color coordination in contmeporary women's fashion collections. (2) Black and white mainly used for achromatic color, and brown used the most often, then followed by blue, red, yellow, green and the others for chromatic color in achromatic & chromatic coordination of contmeporary women's fashion collections. (3) The characteristics of achromatic & chromatic color coordination of modern women's fashion collections from 2002 S/S to 2006/07 A/W showed various images according to chromatic colors and tone variation. The combination of achromaticand brown color variations produced an intelligent and sophisticated image. The soft or light chromatic color and chromatic color combination projected soft, feminine and subtle feeling, while the combination of vivid or strong chromatic color and achromatic color projected a clean and strong feeling through contrasting tones of clear and bright colors. The chromatic color of deep or dark tone and black combination demonstrated supernatural and gloomy image. (4)In all four collections, Paris showed most use of two color coordination and then followed by Milan, N.Y, and London. N.Y showed higher rate of using achromatic & chromatic color coordination, and then followed by Paris, London and Milan.

Classifying Color Codes Via k-Mean Clustering and L*a*b* Color Model (k-평균 클러스터링과 L*a*b* 칼라 모델에 의한 칼라코드 분류)

  • Yoo, Hyeon-Joong
    • The Journal of the Korea Contents Association
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    • v.7 no.2
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    • pp.109-116
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    • 2007
  • To reduce the effect of color distortions on reading colors, it is more desirable to statistically process as many pixels in the individual color region as possible. This process may require segmentation, which usually requires edge detection. However, edges in color codes can be disconnected due to various distortions such as dark current, color cross, zipper effect, shade and reflection, to name a few. Edge linking is also a difficult process. In this paper, k-means clustering was performed on the images where edge detectors failed segmentation. Experiments were conducted on 311 images taken in different environments with different cameras. The primary and secondary colors were randomly selected for each color code region. While segmentation rate by edge detectors was 89.4%, the proposed method increased it to 99.4%. Color recognition was performed based on hue, a*, and b* components, with the accuracy of 100% for the successfully segmented cases.

Navy Leaders and Ethics (해군 리더와 윤리)

  • Jung, Ho-Sup
    • Strategy21
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    • s.42
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    • pp.293-317
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    • 2017
  • A series of immoral conducts are repeatedly occurring by some commanders and high-ranking officers in the ROK navy. They are seriously compromising not only harmony and solidarity of the organization, but also pride and morale of members of the service. They seem to be results of the fragile ethical background of the service as well as of failures in military education and training on ethics. This paper sees backgrounds of weak ethical foundations of the navy as follows: the enduring legacies of cultural factors, such as the toxic military culture of the Japanese colonization, dark side of mariners' traditions, the sea-aversive Confucian culture, and unique characteristics in any small organization or society, etc... This paper also suggests the current ethnic systems of the navy are primarily based on responsive measures against misdeeds, rather than fundamental prescriptions for immoral behaviors, in the absence of ethical instrument for warriors. The paper also emphasizes the importance of developing character-based leadership, founded on, above all, respects for human integrity and strong sense of honor. Moreover, the importance of accountability in charging the command, as advocated by the US navy, is also stressed in order to establish a more robust ethic ground within the navy. Based on these analyses, the author proposes that in order to become a stronger and healthier fighting force, the navy needs to make continuous command efforts and organizational innovations to improve ethic principle and moral standard of the service, to strengthen ethics of naval leaders by a robust system of ethical education and training programs, and ultimately to solidify a navy culture in which moral passions and energies are spreading over.

A Study on the Formative Characteristic and Visual Image of the Power Shouldered Jacket (파워 숄더 재킷의 조형적 특성과 시각적 이미지)

  • Kim, Jeong-Mee;Lee, Jung-Soon
    • Journal of the Korea Fashion and Costume Design Association
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    • v.11 no.3
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    • pp.125-134
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    • 2009
  • The purpose of this study is to analyze the formative characteristics of power-shoulder jacket shown in 08/09 F/W and 09/10 F/W London, Paris, Milan, New York collection and extract main expression words for development of semantic differential scales of visual image according to the change in shoulder angle and width of power-shoulder jacket. The result of this study is as follows. Power-shoulder jacket which were worn by 1980 business women have similar cutting with men's suit jacket, but have characteristics of exaggerating the body figure as exaggerated shoulder with pad and tight waist like an inverted triangle silhouette. Power-shoulder jackets shown in collections used glossy and glittering material and dark colors and formed slim silhouette with matches of shoulder line of temperate senses and casual wear. Like this, the power-shoulder jacket was expanded to daily casual wear from traditional formal wear. Main expression words of visual image of jackets according to the changes in angle and width of shoulder differ greatly depending on the expansion degree of angle and width of shoulder. Changes in shoulder angle may look tense, stiff and too much according to the amount of changes. However, it also has the image of sharp but dignified and charismatic. Also, it helps to show body figure more efficiently like being slim and looking taller. Related to the current trend emphasizing shoulder among women, it is evaluated to be stylish and trendy. When the expansion degree is not too much, changes in shoulder width partly show slim and slender waist under the influence of wider shoulder with basic tailored jacket image. However, when the expansion degree is enlarged, image related to the body figure is more definite compared to other visual images.

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