• Title/Summary/Keyword: Key-frame

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Design of a Real-Time Visual Loop Closure Detector using Key Frame Images (키 프레임 영상을 이용한 실시간 시각 루프 결합 탐지기의 설계)

  • Kim, Hye-Suk;Kim, Joo-Hee;Kim, Dong-Ha;Kim, In-Cheol
    • Proceedings of the Korea Information Processing Society Conference
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    • 2014.11a
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    • pp.809-812
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    • 2014
  • 본 논문에서는 키 프레임 영상을 이용한 효과적인 실시간 시각 루프 결합 탐지기를 제안한다. 시각 루프 결합 탐지기는 과거에 지나온 위치들 중 하나를 다시 재방문하였는지를 판단하기 위해, 새로운 입력 영상을 이미 지나온 위치들에서 수집한 과거 영상들과 모두 비교해 보아야 한다. 따라서 새로운 위치나 장소를 방문할수록 비교 대상 영상들이 계속해서 증가하기 때문에, 일반적으로 루프 결합 탐지는 높은 정확도와 실시간성을 동시에 만족하기 어렵다. 이러한 문제점을 극복하기 위해, 본 시스템에서는 입력 영상들 중에서 키 프레임들만을 골라 비교함으로써, 루프 결합 탐지에 필요한 비교 연산량을 효과적으로 줄이는 방법을 채택하였다. 또한 본 시스템에서는 루프 결합 탐지의 정확도와 효율성을 높이기 위해, 키 프레임 영상들을 시각 단어들의 집합(BoW)으로 표현하고, DBoW 데이터베이스 시스템을 이용해 키 프레임 영상들에 대한 색인을 구성하였다. TUM 대학의 벤치마크 데이터들을 이용한 성능 분석 실험을 통해, 본 논문에서 제안한 시각 루프 결합 탐지기의 높은 성능을 확인할 수 있었다.

Definition and Generation of Level 0 Product for KOMPSAT-2

  • Shin, Ji-Hyeon;Kim, Moon-Gyu;Park, Sung-Og
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.810-814
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    • 2002
  • According to the image level definition for KOMPSAT-2 in KOMPSAT-2 Ground Station Specification, the level 0 is frame formatted, unprocessed data at full resolution; any and all communications artifacts (e.g., synchronization frames, communications headers) removed. The level 0 is used for two purposes: 1) exchange of imagery between image receiving & processing element (IRPE), and 2) image transfer from the Receiving & Archiving Subsystem to Search & Processing Subsystem. On-board processing of imagery data of KOMPSAT-2 includes JPEG-like compression and encryption besides conventional CCSDS packetization. The encryption is used to secure imagery data from any intervention during downlink and compression allows real-time downlink of image data reducing data rate produced from the camera. While developing ground receiving system for KOMPSAT-2, it was necessarily to define level 0 products. In this paper, we will suggest level 0 product definition for KOMPSAT-2 and explain reasons of the decisions made. The key factor used while defining the level 0 products is the efficiency of whole ground receiving system. The latter half of the paper will explain the implementation of software that generates level 0 products. The necessary steps to produce level 0 products will be explained, and the performance achieved will be presented.

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Importance of family segregation in the American College of Medical Genetics and Genomics and Association of Molecular Pathology guidelines: Case of a Korean family with autosomal dominant polycystic disease

  • Kwon, Won Kyung;Kim, Suhee;Jang, Ja-Hyun;Kim, Jong-Won
    • Journal of Genetic Medicine
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    • v.17 no.1
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    • pp.51-54
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    • 2020
  • Since the American College of Medical Genetics and Genomics and Association of Molecular Pathology published their guidelines in 2015, most interpretations of genetic tests have followed them. However, all variants have only limited evidence along 28 interpretation standards, especially de novo variants. When de novo variants, which are classified as variants of uncertain significance (VUS) due to lack of evidence, are detected, segregation in the affected family could provide an important key to clarifying the variants. Autosomal dominant polycystic kidney disease is the most common inherited kidney disorder with pathogenic variants in the PKD1 or PKD2 genes. We detected a novel in-frame deletion variant in the PKD1 gene, c.7575_7577del (p.(Cys2526del)), which was interpreted as a VUS. We analyzed this variant in a Korean family to decide for segregation. Here, we report the variant as a likely pathogenic variant based on the evidence of segregation in three affected relatives and two unaffected members.

A Stabilization of MC-BCS-SPL Scheme for Distributed Compressed Video Sensing (분산 압축 비디오 센싱을 위한 MC-BCS-SPL 기법의 안정화 알고리즘)

  • Ryu, Joong-seon;Kim, Jin-soo
    • Journal of Korea Multimedia Society
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    • v.20 no.5
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    • pp.731-739
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    • 2017
  • Distributed compressed video sensing (DCVS) is a framework that integrates both compressed sensing and distributed video coding characteristics to achieve a low complexity video sampling. In DCVS schemes, motion estimation & motion compensation is employed at the decoder side, similarly to distributed video coding (DVC), for a low-complex encoder. However, since a simple BCS-SPL algorithm is applied to a residual arising from motion estimation and compensation in conventional MC-BCS-SPL (motion compensated block compressed sensing with smoothed projected Landweber) scheme, the reconstructed visual qualities are severly degraded in Wyner-Ziv (WZ) frames. Furthermore, the scheme takes lots of iteration to reconstruct WZ frames. In this paper, the conventional MC-BCS-SPL algorithm is improved to be operated in more effective way in WZ frames. That is, first, the proposed algorithm calculates a correlation coefficient between two reference key frames and, then, by selecting adaptively the reference frame, the residual reconstruction in pixel domain is performed to the conventional BCS-SPL scheme. Experimental results show that the proposed algorithm achieves significantly better visual qualities than conventional MC-BCS-SPL algorithm, while resulting in the significant reduction of the decoding time.

Effect of crack location on buckling analysis and SIF of cracked plates under tension

  • Memarzadeh, Parham;Mousavian, Sayedmohammad;Ghehi, Mohammad Hosseini;Zirakian, Tadeh
    • Steel and Composite Structures
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    • v.35 no.2
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    • pp.215-235
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    • 2020
  • Cracks and defects may occur anywhere in a plate under tension. Cracks can affect the buckling stability performance and even the failure mode of the plate. A search of the literature reveals that the reported research has mostly focused on the study of plates with central and small cracks. Considering the effectiveness of cracks on the buckling behavior of plates, this study intends to investigate the effects of some key parameters, i.e., crack size and location as well as the plate aspect ratio and support conditions, on the buckling behavior, stress intensity factor (SIF), and the failure mode (buckling or fracture) in cracked plates under tension. To this end, a sophisticated mathematical code was developed using MATLAB in the frame-work of extended finite element method (XFEM) in order to analyze the buckling stability and collapse of numerous plate models. The results and findings of this research endeavor show that, in addition to the plate aspect ratio and support conditions, careful consideration of the crack location and size can be quite effective in buckling behavior assessment and failure mode prediction as well as SIF evaluation of the cracked plates subjected to tensile loading.

A Case Study on Big Data Analysis Systems for Policy Proposals of Engineering Education (공학교육 정책제안을 위한 빅데이터 분석 시스템 사례 분석 연구)

  • Kim, JaeHee;Yoo, Mina
    • Journal of Engineering Education Research
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    • v.22 no.5
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    • pp.37-48
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    • 2019
  • The government has tried to develop a platform for systematically collecting and managing engineering education data for policy proposals. However, there have been few cases of big data analysis platform for policy proposals in engineering education, and it is difficult to determine the major function of the platform, the purpose of using big data, and the method of data collection. This study aims to collect the cases of big data analysis systems for the development of a big data system for educational policy proposals, and to conduct a study to analyze cases using the analysis frame of key elements to consider in developing a big data analysis platform. In order to analyze the case of big data system for engineering education policy proposals, 24 systems collecting and managing big data were selected. The analysis framework was developed based on literature reviews and the results of the case analysis were presented. The results of this study are expected to provide from macro-level such as what functions the platform should perform in developing a big data system and how to collect data, what analysis techniques should be adopted, and how to visualize the data analysis results.

Investigation of major parameters affecting instablility of steel beams with RBS moment connections

  • Tabar, A.Moslehi;Deylami, A.
    • Steel and Composite Structures
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    • v.6 no.3
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    • pp.203-219
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    • 2006
  • One of the most promising ways through which a steel moment frame may attain high energy dissipating capability is to trim off a portion of the beam flanges near the column face. This type of moment connection, known as Reduced Beam Section (RBS) connection, has notable superiority in comparison with other moment connection types. As the result of the advantages of RBS moment connection, it has widely being used in practice. In spite of the good hysteretic behaviour, an RBS beam suffers from an undesirable drawback, which is local and lateral instability of the beam. The instability in the RBS beam reduces beam load-carrying capacity. This paper aims to investigate key issues influencing cyclic behaviour of RBS beams. To this end, a numerical analysis was conducted on a series of steel subassemblies with various geometric properties. The obtained results together with the existing experimental data are used to study the instability of RBS beams. A new slenderness concept is presented to control an RBS beam for combined local and lateral instability. This concept is in good agreement with the numerical and experimental results. Finally, a model is developed for the prediction of the magnitude of moment degradation owing to the instability of an RBS beam.

Stay or Return?: Key Decision Factors of Foreign STEM Talents in Korea

  • Kim, Jungbu;Oh, Seong Soo
    • STI Policy Review
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    • v.5 no.2
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    • pp.43-64
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    • 2014
  • Korea has pursued an aggressive policy of inviting more foreign-born students to its universities since the late 1990s in the wake of the globalization of education markets and its changing demographic structure. While increasingly more students from Asia come to Korea for study, more than half of the graduates return home upon graduation. Given the issues of brain drain, brain circulation, and knowledge transfer that are raised by such a high return rate, this paper examines the factors that frame the foreign students' decision on their post-graduation careers. By analyzing survey data, we report that Asian students majoring in science, technology, engineering, and mathematics (STEM) are more likely to return than non-STEM majors. This suggests that Korea's aggressive policies of inviting foreign-born students have contributed to brain circulation and knowledge transfer between Korea and the other Asian countries. We also find that scholarships from Korean sources and positive attitudes toward Korean culture and life increase their inclination to stay in the country upon graduation. These findings, however, raise more questions than answers, since it becomes obvious that their post-graduation decisions are highly affected by what Korea as a society provides.

A Study on the Development of the Contents in Corporate Education Programme - Focusing on the CSR Strategy in China (기업교육 컨텐츠 개발 연구 - 중국 진출을 위한 CSR 전략을 중심으로)

  • An, Hyoung-Tae;Kim, Ji-Young;Myung, Jae-Kyu
    • Journal of Practical Engineering Education
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    • v.10 no.2
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    • pp.149-157
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    • 2018
  • China evaluates corporate management activities based on the policies and assessment criteria of corporate social responsibility (CSR) based on the national development plan goals. This assessment should be understood in advance as a key issue for Korean companies into the Chinese market. Therefore, this research was presented to analyze the process, trends and related systems of CSR based on Chinese political specialties. Through this is aimed at utilizing this study as a CSR implementation strategy and CSR training frame for companies considering to China in order to understand the reality of CSR in China and applying it to business strategy.

Cumulative GHG Reduction Impact Analysis by the Diffusion of Solar Thermal Energy Concerning Technologies for the Residential Sector (주거용 건물부문 태양열 기술 보급에 따른 누적 온실가스 감축 효과 분석)

  • Rhee, Dong-eun;Kim, Seung Jin;Jeon, Eui-Chan
    • Journal of Climate Change Research
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    • v.5 no.3
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    • pp.267-275
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    • 2014
  • A key driver for climate change caused by global average temperature rise is greenhouse gas cumulative emissions that stay for long term in the atmosphere. Although at the moment there is no GHG emission, global warming will continue owing to GHG cumulative emission. In this study, scenarios are developed based on two types of optimistic and conservative diffusion goal. There were a total of 6 alternatives scenarios. The objective of this study are to compare scenarios in terms of GHG cumulative emissions and alternative fuels. An object of analysis is the residential buildings and time frame of scenarios is set up by 2030. And this study uses the LEAP model that is a bottom-up energy model. In conclusion, It is important to set specific diffusion pathway for mitigating climate change virtually.