• Title/Summary/Keyword: Low face

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A Real-time Face Recognition System using Fast Face Detection (빠른 얼굴 검출을 이용한 실시간 얼굴 인식 시스템)

  • Lee Ho-Geun;Jung Sung-Tae
    • Journal of KIISE:Software and Applications
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    • v.32 no.12
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    • pp.1247-1259
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    • 2005
  • This paper proposes a real-time face recognition system which detects multiple faces from low resolution video such as web-camera video. Face recognition system consists of the face detection step and the face classification step. At First, it finds face region candidates by using AdaBoost based object detection method which have fast speed and robust performance. It generates reduced feature vector for each face region candidate by using principle component analysis. At Second, Face classification used Principle Component Analysis and multi-SVM. Experimental result shows that the proposed method achieves real-time face detection and face recognition from low resolution video. Additionally, We implement the auto-tracking face recognition system using the Pan-Tilt Web-camera and radio On/Off digital door-lock system with face recognition system.

Analysis of Instructors' Evaluations and Experiences in Non-Face-to-Face Online Classes at the College of Engineering (공과대학 비대면 온라인 수업의 교수자 평가와 경험 분석)

  • Lee, HyunKyung
    • Journal of Engineering Education Research
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    • v.24 no.5
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    • pp.53-64
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    • 2021
  • The purpose of this study is to provide implications for designing and implementing non-face-to-face online classes at the College of Engineering in the post-corona era by analyzing the instructors' evaluations and experiences of non-face-to-face online classes operated in the COVID-19 pandemic. According to the overall evaluation results of non-face-to-face online classes from instructors at the College of Engineering, 'instructional design' was the highest among the five areas including instructional design, learning management, learning support, learning evaluation, and instructional outcomes. In addition, the effectiveness of non-face-to-face online experimental or practical classes was found to be relatively low. The results of this study imply that the instructors need to consider several instructional strategies such as active interaction with learners, clear explanation, and the use of technology in non-face-to-face online engineering classes.

The Effect of Learners' Interactions on Learning Satisfaction in Non-face-to-face Classes

  • Min Ju, Koo;Jong Keun, Park
    • International Journal of Advanced Culture Technology
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    • v.10 no.4
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    • pp.304-315
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    • 2022
  • The effect on learning satisfaction was compared and analyzed according to the interaction of learners in non-face-to-face classes. 38 students enrolled in the Department of Chemistry Education at G University in Gyeongnam were selected for the study. As a result of analyzing the change in learning satisfaction according to learners' interactions, positive correlations between them were shown in non-face-to-face classes. The type of classes mainly consisted of non-face-to-face real-time classes, and despite the non-face-to-face classes environment, learners focused on classes and put a lot of effort to strengthen learning. Among learners' interactions, the effect of learner-content interaction on learning satisfaction was relatively the highest, while the effect of learner-learner interaction and learner-instructor interaction on learning satisfaction was low. It was found that learners' teaching-learning in non-face-to-face classes relied heavily on learning content, and interactions with fellow learners and instructors were very limited.

Performance Analysis of Face Recognition by Face Image resolutions using CNN without Backpropergation and LDA (역전파가 제거된 CNN과 LDA를 이용한 얼굴 영상 해상도별 얼굴 인식률 분석)

  • Moon, Hae-Min;Park, Jin-Won;Pan, Sung Bum
    • Smart Media Journal
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    • v.5 no.1
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    • pp.24-29
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    • 2016
  • To satisfy the needs of high-level intelligent surveillance system, it shall be able to extract objects and classify to identify precise information on the object. The representative method to identify one's identity is face recognition that is caused a change in the recognition rate according to environmental factors such as illumination, background and angle of camera. In this paper, we analyze the robust face recognition of face image by changing the distance through a variety of experiments. The experiment was conducted by real face images of 1m to 5m. The method of face recognition based on Linear Discriminant Analysis show the best performance in average 75.4% when a large number of face images per one person is used for training. However, face recognition based on Convolution Neural Network show the best performance in average 69.8% when the number of face images per one person is less than five. In addition, rate of low resolution face recognition decrease rapidly when the size of the face image is smaller than $15{\times}15$.

Low Resistance Indium-based Ohmic Contacts to N-face n-GaN for GaN-based Vertical Light Emitting Diodes (GaN계 수직형 발광 다이오드를 위한 N-face n-GaN의 인듐계 저저항 오믹접촉 연구)

  • Kang, Ki Man;Park, Min Joo;Kwak, Joon Seop;Kim, Hyun Soo;Kwon, Kwang Woo;Kim, Young Ho
    • Korean Journal of Metals and Materials
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    • v.48 no.5
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    • pp.456-461
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    • 2010
  • We investigated the In-based ohmic contacts on Nitrogen-face (N-face) n-type GaN, as well as Ga-face n-type GaN, for InGaN-based vertical Light Emitting Diodes (LEDs). For this purpose, we fabricated Circular Transfer Length Method (CTLM) patterns on the N-face n-GaN that were prepared by using a laser-lift off method, as well as on the Ga-face n-GaN that were prepared by using a dry etching method. Then, In/transparent conducting oxide (TCO) and In/TiW schemes were deposited on the CTLM in order for low resistance ohmic contacts to form. The In/TCO scheme on the Ga-face n-GaN showed high specific contact resistance, while the minimum specific contact resistance was only 3${\times}$10$^{-2}$ $\Omega$-cm$^{2}$ after annealing at 300${^{\circ}C}$, which can be attributed to the high sheet resistance of the TCO layer. In contrast, the In/TiW scheme on the Ga-face n-GaN produced low specific contact resistance of 2.1${\times}$10$^{5}$ $\Omega$-cm$^{2}$ after annealing at 500${^{\circ}C}$ for 1 min. In addition, the In/TiW scheme on the N-face n-GaN also resulted in a low specific contact resistance of 2.2${\times}$10$^{-4}$ $\Omega$-cm$^{2}$ after annealing at 300${^{\circ}C}$. These results suggest that both the Ga-face n-GaN and N-face n-GaN.

The effect of changes in the difficulty level of concepts by semester and changes in class types on academic achievement by level

  • Min Ju Koo;Dong-Seon Shin;Jong Keun Park
    • International Journal of Advanced Culture Technology
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    • v.11 no.3
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    • pp.211-224
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    • 2023
  • This study surveyed 2nd graders of B high school and 1st graders of A university in Gyeongnam on factors such as behavior control and interaction in non-face-to-face classes, easy or difficult concepts presented in chemistry I and general chemistry textbooks. Based on the results of the survey, the effect of changes in the difficulty level of concepts presented in chemistry I and general chemistry and changes in class types (face-to-face and non-face-to-face) on students' academic achievement by level was compared and analyzed. In the face-to-face class, the average score between the first and second semesters was similar according to the change in the difficulty of the concepts presented in chemistry I and general chemistry. In the non-face-to-face class, the average score of chemistry I in the second semester was quite low, and the average score of general chemistry was rather high. In non-face-to-face classes, the average score of chemistry I in the second semester of low-level students was significantly lowered due to changes in the difficulty of the concept and changes in class types on academic achievement by level. In the case of 10% of students at the lower level, the academic achievement of chemistry I decreased in both the second semester regardless of the changes in the difficulty level of concepts and the changes in class types.

A variation of face recognition rate according to the reduction of low dimension in PCA method (PCA 저차원 축소에 따른 조명 있는 얼굴의 인식률 변화)

  • Song, Young-Jun;Kim, Dong-Woo;Kim, Young-Gil;Kim, Nam
    • Proceedings of the Korea Contents Association Conference
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    • 2006.11a
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    • pp.533-535
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    • 2006
  • In this paper, we experiment a face recognition rate of the shaded faces except to low dimension feature vectors; first, second, third dimension. It is known to robust the face recognition against illumination. But, it isn't obvious what is effect to recognition in terms of low dimension. We are analysis to the effect of low dimension(first, second, third dimension, and combination of these) under the shaded faces.

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Geometrically nonlinear analysis of sandwich beams under low velocity impact: analytical and experimental investigation

  • Salami, Sattar Jedari;Dariushi, Soheil
    • Steel and Composite Structures
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    • v.27 no.3
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    • pp.273-283
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    • 2018
  • Nonlinear low velocity impact response of sandwich beam with laminated composite face sheets and soft core is studied based on Extended High Order Sandwich Panel Theory (EHSAPT). The face sheets follow the Third order shear deformation beam theory (TSDT) that has hitherto not reported in conventional EHSAPT. Besides, the two dimensional elasticity is used for the core. The nonlinear Von Karman type relations for strains of face sheets and the core are adopted. Contact force between the impactor and the beam is obtained using the modified Hertz law. The field equations are derived via the Ritz based applied to the total energy of the system. The solution is obtained in the time domain by implementing the well-known Runge-Kutta method. The effects of boundary conditions, core-to-face sheet thickness ratio, initial velocity of the impactor, the impactor mass and position of the impactor are studied in detail. It is found that each of these parameters have significant effect on the impact characteristics which should be considered. Finally, some low velocity impact tests have been carried out by Drop Hammer Testing Machine. The contact force histories predicted by EHSAPT are in good agreement with that obtained by experimental results.

The Effect of Factors such as Changes in the Degree of Difficulty of Concepts Presented in the Chemistry I Textbook, Changes in Class Types, etc. on Academic Achievement by Level

  • Min Ju Koo;Dong-Seon Shin;Jong Keun Park
    • International Journal of Advanced Culture Technology
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    • v.11 no.2
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    • pp.210-220
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    • 2023
  • We analyzed and compared factors such as changes in the degree of difficulty of concepts presented in Chemistry I textbook, changes in class types (non-face-to-face, face-to-face), etc. on academic achievement by level (upper, middle, and lower). Students from A high school in Gyeongsangnam-do were selected for the subjects of the study. As a result of analyzing the change in the degree of difficulty of concepts, the total score of chemistry I combined by non-face-to-face and face-to-face classes during the second semester was lower than that of the first semester. As a result of analyzing the impact of factors such as changes in conceptual difficulty, changes in class types, etc. on academic achievement by level, students' grades at the 'lower level' by non-face-to-face classes were lower than those by face-to-face classes. In particular, at the lower level of the second semester, there was a large difference in grades between non-face-to-face and face-to-face classes. In the results of these studies, it was found that instructors' active feedback is important to identify difficulties in understanding learning contents for students with low levels of academic achievement and improve them at the same time.

Analysis characters of distortion of inclined mechanical face seal (경사진 기계평면시일의 변형거동 특성 해석)

  • 조승현;고영배;김청균
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.11a
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    • pp.341-349
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    • 2001
  • Heat distortion of the non-contacting mechanical face seal is affected by friction heat between primary seal and seal sheet. The fluid or gas in mechanical face seal maintains operating gap, cooling friction heat and lubricates at the face of seal. So we designed face of seal for inclined face. inclined face of seal improves fluid or gas flow at the face of seal and it increases circumferential velocity at outer radius of the seal so temperature of the seal is decreased by low heat transfer coefficient at there. In this paper, inclined face seal are analysed numerically using finite element method for proof improve inclined face seal performance. Angle of the incline face used for FEA is from 50$^{\circ}$to 90$^{\circ}$and for explaining the effects of inclined face in seal, we get temperature, face distortion, and stress in the seal with variable operating gap and rotating speeds. Result of analysis shows that angle of the incline face is 60$^{\circ}$come to good thermal distortion characteristics.

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