• 대한수학회지
• /
• 제58권4호
• /
• pp.849-871
• /
• 2021

A (positive definite integral) quadratic form is called even 2-universal if it represents all even quadratic forms of rank 2. In this article, we prove that there are at most 55 even 2-universal even quadratic forms of rank 5. The proofs of even 2-universalities of some candidates will be given so that exactly 20 candidates remain unproven.

• 천문학회보
• /
• 제44권2호
• /
• pp.66.1-66.1
• /
• 2019

We study cosmological shock waves in and around protoclusters at cosmic noon in the Horizon Run 5 Simulation (HR5), one of the world's largest hydrodynamic cosmological simulations. We select the local peaks of X-ray luminosity at z=2.5-3 in the HR5 lightcone volume as protocluster candidates. We find shock waves with Ms > 1.3 within the virial radii of the HR5 protocluster candidates by applying several shock-finding algorithms based on the Rankine-Hugoniot jump condition. We compare the properties of shock waves from different shock-finding algorithms.

• Genomics & Informatics
• /
• 제10권1호
• /
• pp.33-39
• /
• 2012

High-throughput genomic technologies (HGTs), including next-generation DNA sequencing (NGS), microarray, and serial analysis of gene expression (SAGE), have become effective experimental tools for cancer genomics to identify cancer-associated somatic genomic alterations and genes. The main hurdle in cancer genomics is to identify the real causative mutations or genes out of many candidates from an HGT-based cancer genomic analysis. One useful approach is to refer to known cancer genes and associated information. The list of known cancer genes can be used to determine candidates of cancer driver mutations, while cancer gene-related information, including gene expression, protein-protein interaction, and pathways, can be useful for scoring novel candidates. Some cancer gene or mutation databases exist for this purpose, but few specialized tools exist for an automated analysis of a long gene list from an HGT-based cancer genomic analysis. This report presents a new web-accessible bioinformatic tool, called CaGe, a cancer genome annotation system for the assessment of candidates of cancer genes from HGT-based cancer genomics. The tool provides users with information on cancer-related genes, mutations, pathways, and associated annotations through annotation and browsing functions. With this tool, researchers can classify their candidate genes from cancer genome studies into either previously reported or novel categories of cancer genes and gain insight into underlying carcinogenic mechanisms through a pathway analysis. We show the usefulness of CaGe by assessing its performance in annotating somatic mutations from a published small cell lung cancer study.

• 천문학회보
• /
• 제38권2호
• /
• pp.68.2-68.2
• /
• 2013

Camera for QUasars in EArly uNiverse (CQUEAN) is an optical CCD camera system made by Center for Exploration of the Origin of the Universe (CEOU). CQUEAN is developed for follow-up observation of red sources such as high-redshift quasar candidates ($z{\geq}5$), gamma-ray bursts (GRB), brown dwarfs and young stellar objects. The CQUEAN is composed of a science camera with deep-depletion CCD chip which is sensitive at around $1{\mu}m$, a set of custom-made wide-band filters for detection of quasar candidates at z~5, and a guide camera. A focal reducer was developed to secure $4.8^{\prime}{\times}4.8^{\prime}$ field of view, and an in-house user software for efficient data acquisition. CQUEAN was attached to 2.1m Otto Struve Telescope in McDonald Observatory, USA, in August 2010. About 1000 quasar candidates including 3 confirmed with follow-up spectroscopy, have been observed so far, and many high-z galaxy cluster candidates, GRBs and supernovae were also observed. And monitoring of HBC 722, a young stellar object, is under way since 2011. Further enhancement of CQUEAN including the introduction of narrow-band filters is planned.

• 인지과학
• /
• 제19권3호
• /
• pp.297-310
• /
• 2008

화행은 화자의 의도를 내포하기 때문에 지능형 대화 시스템을 구현할 때 화행 분석은 필수적이다. 본 논문에서는 효과적인 화행 분석을 위한 2단계 모델을 제안한다. 첫 번째 단계에서 기계 학습 기반의 신경망 모델과 확률 기반의 예측도 모델을 이용하여 개별적으로 화행 후보를 생성한다. 두 번째 단계에서는 신경망 모델이 출력한 화행 후보들을 예측도 모델이 출력한 화행 후보들로 필터링한 후, 남겨진 후보들 중에서 최대값을 가지는 화행을 선택한다. 일정관리 영역에서의 실험 결과, 제안한 2단계 모델링 방법이 기계 학습 모델이나 확률 모델만을 사용하는 기존의 방법들보다 좋은 성능을 보였다.

• 한국언론정보학보
• /
• 제42권
• /
• pp.79-106
• /
• 2008

이 연구는 제17대 대통령선거 과정에서 미디어 정치에 대한 유권자의 인식을 조사하고 대중매체가 유권자의 후보인식에 미치는 영향에 대하여 제3자 효과를 중심으로 온라인 서베이를 실시하였다. 연구 결과, 미디어가 후보자의 이미지 형성에 미친 영향의 정도에서 제3자 효과가 검증되었으며, 신문, TV, 인터넷과 같은 각 매체가 후보자 선택에 미치는 영향에서도 제3자 효과가 다르게 나타났다. 후보자 선택에서는 신문의 영향력이 큰 것으로 나타났고, 후보 이미지 형성에서는 TV가 상대적으로 영향력이 크게 나타났다. 또 다른 주목할 만한 연구결과는 이명박, 정동영, 이회창 후보의 지지자는 후보 이미지 속성에 따라 지지여부와 달리 이미지 속성별로 다른 후보를 높게 평가함으로써 용모와 말솜씨, 도덕성과 같은 일부 이미지 속성이 유권자의 투표행위에 직접적인 영향을 주지 않았음을 시사하고 있다.

• 천문학회보
• /
• 제41권2호
• /
• pp.38.3-39
• /
• 2016

We present the results of a search for Very Low-Luminosity Objects (VeLLOs) in the Gould Belt (GB) clouds using infrared and sub-millimeter (sub-mm) data from 1.25 to $850{\mu}m$ and our N2H+ (J = 1-0) observations. We modified the criteria by Dunham et al. to select the VeLLOs in the GB clouds, finding 95 VeLLO candidates, 79 of which are newly identified in this study. Out of 95 sources, 44 were detected in both sub-mm continuum and N2H+ emission and were classified as Group A (the VeLLOs), and 51 sources detected in either sub-mm emission or N2H+ emission were classified with Group B as candidate VeLLOs. We find that these VeLLOs and the candidates are forming in environments different from those of the likely VeLLOs. Seventy-eight sources are embedded within their molecular clouds, and thus are likely VeLLOs forming in a dense environment. The remaining 17 sources are located in low-level extinction regions (Av < 1) connected to the clouds, and can be either background sources or candidate substellar objects forming in an isolated mode. The VeLLOs and the candidates are likely more luminous and their envelopes tend to be more massive in denser environments. The VeLLOs and the candidates are more populous in the clouds where more YSOs form, indicating that they form in a manner similar to that of normal YSOs. The bolometric luminosities and temperatures of the VeLLOs are compared to predictions of episodic accretion models, showing that the low luminosities for most VeLLOs can be well explained by their status in the quiescent phases of a cycle of episodic mass accretion.

• 공업화학
• /
• 제28권3호
• /
• pp.294-298
• /
• 2017

Dimethyl terephthalate (DMT) 생산과정의 부산물로서 폐기 처리되어왔던 methyl 4-formylbenzoate (MFB)를 출발 물질로하여 고급 형광증백제 family인 Uvitex FP와 동일한 4,4'-di((E)-styryl)-1,1'-biphenyl 기본 골격을 갖는 새로운 형광증백제(fluorescent whitening agent) 후보 물질 6종을 합성하였다. 후보 물질 6종은 MFB 및 그의 유도체와 tetraethyl biphenyl-4,4'-diylbis(methylene) diphosphonate (3)와 Wittig-Horner 반응을 이용하여 합성하였다. 합성된 6종에 대하여 형광증백제로의 가능성을 확인하기 위하여 UV spectrum을 기록하여 몰흡광 계수를 얻었으며, 6종 모두 Uvitex FP 127(log ${\varepsilon}$ 4.85)보다 낮은 몰흡광 계수(log ${\varepsilon}$ 3.95~2.60)를 보임으로서 형광증백제로는 적합하지 못한 것을 확인하였다.

• 대한임베디드공학회논문지
• /
• 제11권6호
• /
• pp.361-367
• /
• 2016

In this paper, we propose an improved single view metrology (SVM) algorithm to accurately measure the height of objects. In order to accurately measure the size of objects, vanishing points have to be correctly estimated. There are two methods to estimate vanishing points. First, the user has to choose some horizontal and vertical lines in real world. Then, the user finds the cross points of the lines. Second, the user can obtain the vanishing points by using software algorithm such as [6-9]. In the former method, the user has to choose the lines manually to obtain accurate vanishing points. On the other hand, the latter method uses software algorithm to automatically obtain vanishing points. In this paper, we apply image resizing and edge sharpening as a pre-processing to the algorithm in order to improve performance. The estimated vanishing points algorithm create four vanishing point candidates: two points are horizontal candidates and the other two points are vertical candidates. However, a common image has two horizontal vanishing points and one vertical vanishing point. Thus, we eliminate a vertical vanishing point candidate by analyzing the histogram of angle distribution of vanishing point candidates. Experimental results show that the proposed algorithm outperforms conventional methods, [6] and [7]. In addition, the algorithm obtains similar performance with manual method with less than 5% of the measurement error.

• 대한전자공학회논문지SP
• /
• 제38권6호
• /
• pp.721-734
• /
• 2001

제안된 연구는 유방촬영영상(Mammogram)에서 종양의 추출에 관한 연구로서, 맘모그램의 특성을 파악하여 종양에 대한 자동적인 추출을 시행하였다. 처리과정에서 동질성 특성을 이용하여 정상조직인 Cooper's ligament로부터 종양조직을 분리하였고 고밀도 후보에 대한 처리방법으로 다중 문턱값 적용방식을 사용하였다. 추출된 부분을 8-연결성 관계를 사용하여 1차 후보를 추출하였다. 1차 추출된 각 후보에 대하여 명암값을 지형적 높이정보로 해석한 이분화영상으로 표현하여 이중원형성과 분포 비율을 비교하는 방법을 통하여 2차 후보 추출을 시행하였다. 최종적인 종양의 결정은 공간원형성 판단을 위한 반구 형태의 템플리트를 생성하여 비교하는 방법을 이용하여 후보에 대한 순위를 결정하였다. 알고리즘을 실제 종양이 확진된 환자의 136 예에 적용하여 추출된 결과와 전문의가 지적한 결과를 비교하여 93.38%의 민감도를 얻었으며, 최종추출 단계에서는 124 예에서 1 순위로 종양을 추출하여 97.63%의 FP(False positive)의 결과를 나타냈다.