• Title/Summary/Keyword: Backgrounds

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Hand Raising Pose Detection in the Images of a Single Camera for Mobile Robot (주행 로봇을 위한 단일 카메라 영상에서 손든 자세 검출 알고리즘)

  • Kwon, Gi-Il
    • The Journal of Korea Robotics Society
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    • v.10 no.4
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    • pp.223-229
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    • 2015
  • This paper proposes a novel method for detection of hand raising poses from images acquired from a single camera attached to a mobile robot that navigates unknown dynamic environments. Due to unconstrained illumination, a high level of variance in human appearances and unpredictable backgrounds, detecting hand raising gestures from an image acquired from a camera attached to a mobile robot is very challenging. The proposed method first detects faces to determine the region of interest (ROI), and in this ROI, we detect hands by using a HOG-based hand detector. By using the color distribution of the face region, we evaluate each candidate in the detected hand region. To deal with cases of failure in face detection, we also use a HOG-based hand raising pose detector. Unlike other hand raising pose detector systems, we evaluate our algorithm with images acquired from the camera and images obtained from the Internet that contain unknown backgrounds and unconstrained illumination. The level of variance in hand raising poses in these images is very high. Our experiment results show that the proposed method robustly detects hand raising poses in complex backgrounds and unknown lighting conditions.

Mathematical Knowledge for Teaching and Teachers' Backgrounds: A study of U.S. Teachers (교수를 위한 수학적 지식과 교사의 배경: 미국 교사에 관한 연구)

  • Kim, Yeon
    • School Mathematics
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    • v.15 no.3
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    • pp.533-550
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    • 2013
  • Teachers' mathematical knowledge for teaching (MKT) strongly influence student achievement (Hill, Rowan, & Ball, 2005). However, there is generally no record that shows the levels of teachers' MKT in schools and districts. Because of the limited resources, schools and districts need some criteria to decide how to distribute their resources to help teachers improve MKT. This study explores what factors in teachers' backgrounds are related to their levels of MKT. This article examines the relationships between the MKT of 336 elementary teachers and their demographic, educational, and teaching backgrounds. To measure MKT, I used a series of multiple-choice problems. The number of years teaching mathematics is not critical to these measures. Implications are discussed with regard to policy for mathematics teacher education.

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Semantic crack-image identification framework for steel structures using atrous convolution-based Deeplabv3+ Network

  • Ta, Quoc-Bao;Dang, Ngoc-Loi;Kim, Yoon-Chul;Kam, Hyeon-Dong;Kim, Jeong-Tae
    • Smart Structures and Systems
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    • v.30 no.1
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    • pp.17-34
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    • 2022
  • For steel structures, fatigue cracks are critical damage induced by long-term cycle loading and distortion effects. Vision-based crack detection can be a solution to ensure structural integrity and performance by continuous monitoring and non-destructive assessment. A critical issue is to distinguish cracks from other features in captured images which possibly consist of complex backgrounds such as handwritings and marks, which were made to record crack patterns and lengths during periodic visual inspections. This study presents a parametric study on image-based crack identification for orthotropic steel bridge decks using captured images with complicated backgrounds. Firstly, a framework for vision-based crack segmentation using the atrous convolution-based Deeplapv3+ network (ACDN) is designed. Secondly, features on crack images are labeled to build three databanks by consideration of objects in the backgrounds. Thirdly, evaluation metrics computed from the trained ACDN models are utilized to evaluate the effects of obstacles on crack detection results. Finally, various training parameters, including image sizes, hyper-parameters, and the number of training images, are optimized for the ACDN model of crack detection. The result demonstrated that fatigue cracks could be identified by the trained ACDN models, and the accuracy of the crack-detection result was improved by optimizing the training parameters. It enables the applicability of the vision-based technique for early detecting tiny fatigue cracks in steel structures.

Educational Support for Low-Performing Students with Multicultural Backgrounds with Reference to Basic Academic Competency of Elementary/Middle School Students (초·중 다문화 가정 학습 부진 학생 교과 교육 지원을 위한 기초 연구)

  • Goo, Youngsan
    • The Journal of the Korea Contents Association
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    • v.16 no.5
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    • pp.361-374
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    • 2016
  • The study aims to gain information for developing educational content to support LPSMBs (low-performing students with multicultural backgrounds) in elementary and middle schools. The procedure involved surveying students about their personal characteristics, attitudes related to learning, and learning environment. I analyzed responses from 1,147 students from 200 elementary schools and 3,760 students from 320 middle schools who were LPSMBs and NPSMBs (normally performing students with multicultural backgrounds). LPSMBs in both elementary and middle school showed statistically significant lower scores on most questionnaires related to learning and learning environment than NPSMBs. LPSMBs in elementary schools showed higher scores on teachers' learning support, LPSMBs in middle school showed higher scores on classmates' learning support. LPSMBs born in foreign countries need to be given opportunities to learn Korean as well as their father's and mother's culture. I give suggestions for how to support LPSMBs' learning and learning environment based on the survey results.

Detection of Calibration Patterns for Camera Calibration with Irregular Lighting and Complicated Backgrounds

  • Kang, Dong-Joong;Ha, Jong-Eun;Jeong, Mun-Ho
    • International Journal of Control, Automation, and Systems
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    • v.6 no.5
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    • pp.746-754
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    • 2008
  • This paper proposes a method to detect calibration patterns for accurate camera calibration under complicated backgrounds and uneven lighting conditions of industrial fields. Required to measure object dimensions, the preprocessing of camera calibration must be able to extract calibration points from a calibration pattern. However, industrial fields for visual inspection rarely provide the proper lighting conditions for camera calibration of a measurement system. In this paper, a probabilistic criterion is proposed to detect a local set of calibration points, which would guide the extraction of other calibration points in a cluttered background under irregular lighting conditions. If only a local part of the calibration pattern can be seen, input data can be extracted for camera calibration. In an experiment using real images, we verified that the method can be applied to camera calibration for poor quality images obtained under uneven illumination and cluttered background.

End point Control of a Flexible Beam Actuated by Moving Coil and DC Motor (가동코일 및 DC 모터로 작동되는 유연 빔의 끝점 제어)

  • Yoo, Hwa-jun;Nam, Yoon-su
    • Journal of Industrial Technology
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    • v.21 no.B
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    • pp.117-123
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    • 2001
  • In a modern control field, a control engineer who has theoretical backgrounds with some practical knowledge is demanded. That is to say, an engineer who can understand and operate the various parts such as modeling, simulation, system analysis, signal processing, statistics, and hardware is required. In order to prove the theoretical backgrounds and operate various hardwares, a lot of experimental devices for students are designed in universities. Since the conventional experimental devices are manufactured abroad and the prices of the devices are too high, it is difficult to have. If a low cost experimental device can be developed, it will be very useful for a control engineering education. In Ibis paper, an experimental rig which has two control inputs and three sensor outputs to control the end point of a flexible beam is designed and manufactured. This rig can be used for a control field education.

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A Study on the Contents Production for a Clothing Design Analysis - Focused on the Image Medium of Chinese Historical Background - (의상디자인 분석을 위한 콘텐츠 제작에 관한 연구 - 중국역사배경 영상매체를 중심으로 -)

  • Yoon, Hae-Gyung
    • Journal of the Korea Fashion and Costume Design Association
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    • v.8 no.2
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    • pp.61-71
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    • 2006
  • The purpose of this study is to present a contents production process for costume design analysis by take advantage of the image media of Chinese historical backgrounds. The production process of contents for lectures on fashion design analysis can be summarized as follows: The contents for the design analysis of Chinese costumes can be divided into major media and supplementary media. Major media can be completed through the processes including the selection of Chinese historical backgrounds. images and media (video, DVD title or VOD), verification of image capture parts, image captures, and applications of PPT files. Supplementary media consist of production of analysis materials for each item and TPO, report preparation methods and discussions, and printed matters to be used at the stage of image comparison and verification. This way, a process applicable to the design analysis of Chinese costumes can be presented.

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A Study on the Concept of Topological Space shown Folding in Architecture (접힘 건축에 나타난 위상기하학적 공간 개념에 관한 연구)

  • 황태주
    • Korean Institute of Interior Design Journal
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    • v.13 no.3
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    • pp.69-75
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    • 2004
  • Since 1990s, several rising western architects have been moving their theoretical background from the modern paradigm to new science and philosophy. Architectural spaces are based on the philosophy and science of their own age and the architectural theories made by them. And specially, it seems that topological spaces are different to theoretical backgrounds from idealized spaces of modern architecture. From these backgrounds, this study was performed to search for the spacial relationship and characteristics shown in the recently folding architecture and the results of this study that starts this purpose are as follows. First, the architecture that introduced by the theory of topology has appeared as the circulation forms like as Mobius band or Klein bottle, and was made the space fused with structure pursuing liquid properties of matter. As follows, second, the concept of topological space made the division of traditional concept of floor, wall, ceiling disappeared and had built up the space by continual transformation. Third, about the relationship between two spaces in topological space, the two spaces were happened by transformation of these and they have always continuity and the same quality.

A Study on the Layout of Northern Wei Buddhist Temples in 『Luoyang Qielanji』 (『낙양가람기』에 나타난 북위 낙양 불교사원 배치에 관한 연구)

  • Hyun, Seung-Wook
    • Journal of architectural history
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    • v.23 no.3
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    • pp.35-42
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    • 2014
  • Luoyang Qielanji(洛陽伽藍記) is a document that describes Buddhist Temples in Luoyang, the capital of Northern Wei Dynasty. The purpose of this paper is to analyze the construction backgrounds, architectural elements and layout characteristics of Luoyang Temples in Northern Wei Dynasty. The results are as follows: The construction backgrounds of Luoyang Temples can be categorized into two types: the established-temple (創建型) and the converted-temple(捨宅爲寺型). The layout systems of Luoyang Temples can also be categorized into two main types: The front Pagoda-rear Buddhist Hall layout(前塔後殿), The front Buddhist Hall-rear Lecture Hall layout(前殿後堂). In Luoyang Temples, the pagoda was still an important element of the layout.