• Journal of the Korea Society of Computer and Information
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• v.16 no.1
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• pp.53-59
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• 2011

In many face recognition applications such as security systems, it is assumed that upright faces are given to the system. In order for the system to be used in more general environments, the system should be able to deal with the rotated faces properly. It is a generally used approach to rotate the face detection window and apply face detector repeatedly to detect a rotated face in the given image. But such an approach requires a lot of computation time. In this paper, a method of extracting the axis of symmetry for a given set of points is proposed. The axis of symmetry for the edge points in the face detection window is extracted in a way that is fast and accurate, and the face detector is applied only for that direction. It is shown that the mean and standard deviation of the symmetry detection error is $0^{\circ}$ and $3^{\circ}$ respectively, for the database used.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.6
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• pp.800-807
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• 2016

We propose a fast algorithm using Extreme Contour Point (ECP) to detect the angle of rotated images, is implemented by rotation feature of one covered frame image that can be applied to correct the rotated images like in image processing for real time applications, while CORDIC is inefficient to calculate various points like high definition image since it is only possible to detect rotated angle between one point and the other point. The two advantages of this algorithm, namely compatibility to images in preprocessing by using Sobel edge process for pattern recognition. While the other one is its simplicity for rotated angle detection with cyclic shift of two $1{\times}n$ matrix set without complexity in calculation compared with CORDIC algorithm. In ECP, the edge features of the sample image of gray scale were determined using the Sobel Edge Process. Then, it was subjected to binary code conversion of 0 or 1 with circular boundary to constitute the rotation in invariant conditions. The results were extracted to extreme points of the binary image. Its components expressed not just only the features of angle ${\theta}$ but also the square of radius $r^2$ from the origin of the image. The detected angle of this algorithm is limited only to an angle below 10 degrees but it is appropriate for real time application because it can process a 200 degree with an assumption 20 frames per second. ECP algorithm has an O ($n^2$) in Big O notation that improves the execution time about 7 times the performance if CORDIC algorithm is used.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.9
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• pp.2819-2832
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• 1996

The estimation of the remaining life for the aged components in power plant as well as chemical and petroleum plants has been recently concerned. The raw materials used in this study are the 1Cr-1Mo-0.25V steel which intensified P and S compositions along with the nominal compositions of ASTM A 470 standard. Five kinds of specimens with the different degradation levels were prepared by isothermal aging heat treatment at 630.deg.C. The mechanical properties and rotated bending fatigue strength of virgin and aged 1Cr-1Mo-0.25V steel have been investigated through the hardness, tensile, fatigue test, SEM fractograph and EDS analysis at 538.deg.C and room temperature, respectively. Thus the data of aged specimens were compared with those of virgin specimen to evaluate the aging effects. The main results obtained in this study are as follows ; The decrease of the yield and tensile strength due to degradation was distinguished until 50, 000hrs simulated service time. And it was confirmed that the considerable amount of P, Mn, Cr and S was precipitated at the grain boundary of aged material through the SEM and EDS analysis. The rotated bendingd fatigue strength at 538.deg.C of virgin, 25, 000, 50, 000, 75, 000 and 100, 000 hrs aged material was decreased 44.6 %, 49.6 %, 51.5 %, 52.4% and 53.8% than that of virgin material at 10$_{7}$cycles of room temperature, respectively. The major cracks of virgin and aged materials mainly initiated at the inclusions including Si, P and Mn compositions which were located at the outer periphery of the specimen.n.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.114.1-114.1
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• 2014

Copper is considered to be the most promising substrate for the growth of high-quality and large area graphene by chemical vapor deposition (CVD), in particular, on the (111) facet. Because the interactions between graphene and Cu substrates influence the orientation, quality, and properties of the synthesized graphene, we studied the interactions using angle-resolved photoemission spectroscopy. The evolution of both the Shockley surface state of the Cu(111) and the p band of the graphene was measured from the initial stage of CVD growth to the formation of a monolayer. Graphene growth was initiated along the Cu(111) lattice, where the Dirac band crossed the Fermi energy ($E_F$) at the K point without hybridization with the d-band of Cu. Then two rotated domains were additionally grown as the area covered with graphene became wider. The Dirac energy was about 0.4 eV and the energy of the Shockley surface state of Cu(111) shifted toward the $E_F$) by 0.15 eV upon graphene formation. These results indicate weak interactions between graphene and Cu, and that the electron transfer is limited to that between the Shockley surface state of Cu(111) and the p band of graphene. This weak interaction and slight lattice mismatch between graphene and Cu resulted in the growth of rotated graphene domains ($9.6^{\circ}$ and $8.4^{\circ}$), which showed no significant differences in the Dirac band with respect to different orientations. These rotated graphene domains resulted in grain boundaries which would hinder a large-sized single monolayer growth on Cu substrates.

• Journal of Korean Society of Steel Construction
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• v.14 no.5 s.60
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• pp.657-664
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• 2002

This paper described the ultimate strength and deformation limit of the new uniplanar T-joints in cold-formed square hollow sections. In the configuration of the new T-joint, only a branch member is orientated to a chord member at 45 degrees in the plane of the truss. This study focused on the branch-rotated T-joints that were governed by chord flange failure in previous studies. Test results of the T-joint in cold-formed square hollow sections revealed a deformation limit of 3%B for $16.7{\leq}2{\gamma}(=B/T){\leq}33.3$ and $0.27{\leq}{\beta}(=b1/B){\leq}0.6$. The existing strength formulae for traditional T-joint were determined and a new yield-line model for the branch-rotated T-joint proposed. Finally, the strength formula on the yield-line analysis was compared with test results and the application range of the proposed formula recommended.

• Journal of Korean Society of Transportation
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• v.27 no.1
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• pp.169-177
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• 2009

In this paper, the rotated hexagonal lattice model (RHLM) was proposed, which is applied to pedestrian flow, and developed the simulation model for the pedestrian counterflow. RHLM is an upgrade version of the square lattice model(SLM) and hexagonal lattice model(HLM). The simulation was performed at the hexagonal lattice $20{\times}20$ and evaluated by different speed, density and flow conditions. Simulation results are compared with SLM and show that RHLM can replicate the characteristics of pedestrian traffic more effectively and reliably than any other existing models from several perspectives. First, RHLM can explain the shortest-path movement of pedestrians and more realistic avoidance motion. If they cannot move straight direction, they can move shorter distance from previous position to destination. Second, RHLM reflects the characteristics that the pedestrian can move with higher capacity and the speed of pedestrian flow is hard to zero.

• Journal of Korea Multimedia Society
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• v.16 no.1
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• pp.42-49
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• 2013

The camera motion is accompanied with the translation and/or the rotation of objects in frames of a video sequence. An unnecessary rotation of objects declines the quality of the moving pictures and in addition is a primary cause of the viewers' fatigue. In this paper, a novel method for correcting rotated frames in video sequences is presented, where the modified Mojette transform is applied to the motion-compensated area in each frame. The Mojette transform is one of discrete Radon transforms, and is modified for correcting the rotated frames as follows. First, the bin values in the Mojette transform are determined by using pixels on the projection line and the interpolation of pixels adjacent to the line. Second, the bin values are calculated only at some area determined by the motion estimation between current and reference frames. Finally, only one bin at each projection is computed for reducing the amount of the calculation in the Mojette transform. Through the simulation carried out on various test video sequences, it is shown that the proposed scheme has good performance for correcting the rotation of frames in moving pictures.

• Journal of Korea Multimedia Society
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• v.17 no.9
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• pp.1070-1075
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• 2014

Due to a number of illegal copied videos, many video content markets have been threatened. Since this copied videos have intercepted the profits of the content holders, content developers lose the will to generate new contents. Therefore, video copy detection approaches have been developed to protect the copyrights of video contents. However, many illegal uploader who generate copied videos used video transformations to avoid video copy detection systems. Among of the video transformations, rotation and flipping did not distorted the quality of video contents. Thus, these two video transformations were adopt to generate copied video. In order to detect rotated or flipping copy videos, rotation and flipping robust region binary pattern (RFR) recently was proposed. But, this RFR has a weakness according to rotated angles. Therefore, in order to overcome this problem, multi region binary patterns are proposed in this paper. The proposed method has the similar performance with the original RFR. But, it showed much higher efficiency for memory spaces.

• Journal of the Korean Institute of Telematics and Electronics
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• v.10 no.3
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• pp.53-60
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• 1973

Calculations of the temperature coefficients of the elastic surface wave velocity and delay time were performed for the propagation along the X axis of rotated Y cut plane of the LiNbO3 and LiTaO3. Measurements of the temperature dependence of delay time of the elastic surface wave were also performed for the propagation along the X axis of a 130" rotated Y cut plane of the LiNb03 at the temperature range from liquid He to room temperature. Experimental value 70$\times$10-6/$^{\circ}C$ of the temperature coefficient of the delay time of the elastic surface wave agrees well with the calculated value 72.7$\times$10-a/$^{\circ}C$. The temperature coefficient of delay time of elastic surface wave propagating along the X axis of a 130$^{\circ}$ rotated Y cut plane o( the LiNbO3 is approximately 16$\times$10-6/$^{\circ}C$ at the near temperature of liquid He.d He.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.659-662
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• 2002

The present paper presents the experimental results for pressure drop in inclined tube bundles located in a rectangular duct. Measurements are made for pressure drop in triangular and rotated triangular tube arrays having P/d ratio of 1.6 and inclination angles of 30,45,60 and 90 degrees. The Reynolds number based on the free stream velocity and tube diameter ranges from $8{\times}10^2\;to\;6.3{\times}10^{4}$. The experimental results show that the magnitude of dimensionless pressure drop decreases significantly when the inclined angle is less than 45 degree. The measured data are compared with two existing correlations available in the literatures. The ESDU correlation agrees well with the present data far the triangular arrays. But some discrepancies are observed for the rotated triangular arrays when the inclined angles are 30 and 45 degrees. The Idel'chik correlation generally agrees well with the measured data for the rotated triangular arrays except for the inclined angle of 30 degree. The Idel'chik correlation needs modification for the triangular arrays. The modified Idel'chik correlation agrees well with the measured data within $10{\%}$. It is found that the present measured data can be applied to the evaluation and modification of previous correlations.