• Journal of Information Processing Systems
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• v.16 no.3
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• pp.663-676
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• 2020

Plant leaf classification is a significant application of image processing techniques in modern agriculture. In this paper, a multi-granular angle description method is proposed for plant leaf classification and retrieval. The proposed method can describe leaf information from coarse to fine using multi-granular angle features. In the proposed method, each leaf contour is partitioned first with equal arc length under different granularities. And then three kinds of angle features are derived under each granular partition of leaf contour: angle value, angle histogram, and angular ternary pattern. These multi-granular angle features can capture both local and globe information of the leaf contour, and make a comprehensive description. In leaf matching stage, the simple city block metric is used to compute the dissimilarity of each pair of leaf under different granularities. And the matching scores at different granularities are fused based on quotient space theory to obtain the final leaf similarity measurement. Plant leaf classification and retrieval experiments are conducted on two challenging leaf image databases: Swedish leaf database and Flavia leaf database. The experimental results and the comparison with state-of-the-art methods indicate that proposed method has promising classification and retrieval performance.

• Journal of Mechanical Science and Technology
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• v.17 no.6
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• pp.914-924
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• 2003

The interaction and breakdown of vortices over the Leading Edge Extension (LEX) - Delta wing configuration has been investigated through wing-surface pressure measurements, the off-surface flow visualization, and 5-hole probe measurements of the wing wake section. The description focused on analyzing the interaction and the breakdown of vortices depending on the angle of attack and the sideslip angle. The Effect of angle of attack and sideslip angle on the aerodynamic load characteristics of the model is also presented. The sideslip angle was found to be a very influential parameter of the vortex flow over the LEX-delta wing configuration. The introduction of LEX vortex stabilized the vortex flow, and delayed the vortex breakdown up to a higher angle of attack. The vortex interaction and breakdown was promoted on the windward side, whereas it was suppressed on the leeward side.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.3
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• pp.77-86
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• 2002

An experimental study of the vortex interaction characteristics of a delta wing/LEX configuration was conducted in a wind tunnel using the micro water droplet and laser beam sheet visualization technique. The main focus of this study was to analyze the effect of the angle of attack and sideslip angle on the vortex interaction and vortex breakdown. These tests were accomplished at angles of attack between $16^{\circ}$ and $28^{\circ}$ and sideslip angle between $0^{\circ}$ and $-15^{\circ}$ at free-stream velocity of 6.2 m/s. Flow visualization data provide a description of the vortex interaction between LEX and wing vortices, and of the vortex breakdown. The introduction of LEX vortex stabilized the vortical flow, and delayed the vortex breakdown up to higher angle of attack. The vortex interaction and breakdown was promoted on the windward side, whereas they are suppressed on the leeward side.

• East Asian mathematical journal
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• v.26 no.2
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• pp.115-140
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• 2010

The purpose of this paper was to develop manipulative materials to teach the angle concepts and construct a teaching-learning program by using that. Furthermore, this study analyzed how does the program affect students understanding of the angle concepts. To check the effects of learning activities with manipulative materials on the understanding of an angle concepts, applied observation during class and write a mathematics journal writing, a description of students impressions at the end of the class and analyzed before and after test paper. We find that students approached the subject more friendly and knew well about the mathematical concepts by using materials. Furthermore, this activity helped that way to solve add and subtract of the angle, estimate ability, round angle concept, positive response in mathematics learning.

• Journal of the Korean Data and Information Science Society
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• v.21 no.5
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• pp.901-908
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• 2010

A geometrical description method is proposed to represent the process of the forward selection and backward elimination methods among many variable selection methods for multiple regression models. This graphical method shows the process of the forward selection and backward elimination on the first and second quadrants, respectively, of half circle with a unit radius. At each step, the SSR is represented by the norm of vector and the extra SSR or partial determinant coefficient is represented by the angle between two vectors. Some lines are dotted when the partial F test results are statistically significant, so that statistical analysis could be explored. This geometrical description can be obtained the final regression models based on the forward selection and backward elimination methods. And the goodness-of-fit for the model could be explored.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.12
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• pp.90-97
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• 1997

This paper presents a new algorithm for surface segmentation and feature description. The algorithm extracts the signature of an edge image based on the signature technqique[12] in the first stage. If there exists a range in the angle axis where more than two signatures form a closed curve, we can conclude there is a surface inside the range. Using this feature of the signature, surfaces can be segmented. The surface features such as number of vertices, number of edges, and type of surfaces can also be extracted by finding the signatures of individual surfaces. This algorithm has distinguished advantages: it can easily recover the lost part occuring in the edge iage using the curve fitting method and it can extract surface features even when surfaces are rotated in 3-D space.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.3 s.106
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• pp.267-271
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• 2006

In this paper, we use the OFDM transmission channel model applied to the MIMO antennas considering spatial propagation property to evaluate and investigate the ergodic capacity of the channel. Specially, we have applied our results to 3GPP TR 25.99 V1.1.0 case 1 LOS off channel description and calculated ergodic capacity with parameters, cluster angle spread and angle of arrival(AOA). Our results show that as the cluster angle spread increase the channel capacity increase until 35 degree, but for more than 35 degree channel capacity does not improved.

• Communications for Statistical Applications and Methods
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• v.2 no.2
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• pp.310-319
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• 1995

We represent graphically the relationship of hierachical log linear models by regarding the values of the likelihood ratio statistics as the squared norm of the corresponding vectors. Right angled triangles, tetrahedrons, and modified polyhedrons are used for graphical description. We find that the angle between the two vectors depends on the coefficient of determination and the partial coefficent of determination. Thess graphical descriptions could be applied to the model selection method.

• 전기의세계
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• v.27 no.6
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• pp.63-68
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• 1978

To convert into multiphase from single phase are often necessary for industry field. In oder to convert of phase, phase shifted voltages are first buileded by single phase and then must combine with these voltages adequately. This paper aims at the description of the way of phase shift by means of turning on or turning off through natural commutation and forced commutation methods with firing angle of thyristor pating a role of switching controlled adequately. Experimental result of the Phase Shift with the Thyristors Utilized has been turned out to shift the phase to 60.deg., 90.deg., 120.deg., and other angles.

• Economic and Environmental Geology
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• v.23 no.3
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• pp.359-366
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• 1990

Field sampling requires statistical description to draw inferences from data. Field data, or linear structures, are commonly analyzed by the graphical presentations, such as streonets and rose diagrams. For this purpose the DROPOL program is developed to analyze the data more efficiently with personal computer. DROPOL program written in FORTRAN 77 plots the structural data in points, poles or great circle on equalarea (Schmidt net) or equal-angle (Wulff net) projection surface. It is also capable to project the data from upper or lower hemisphere of stereonet and to draw pole contour diagrams from the plotted data. The rose diagram, representing the frequency of the strike and dip angle, can also be drawn in general or smooth type using $5^{\circ}$ or $10^{\circ}$ degrees interval.