• Journal of applied mathematics & informatics
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• v.8 no.2
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• pp.651-658
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• 2001

The projection matrix plays an important role in the linear model theory. In this paper we derive an algebraic relationship between the projection matrices of submatrices of the design matrix. Using this relationship we can easily obtain the projection matrices of any submatrices of the design matrix. Also we show that every projection matrix can be obtained as a linear combination of Kronecker products of identity matrices and matrices with all elements equal to 1.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.177-180
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• 2000

In this paper, we studied efficiency improvement of linear ultrasonic motor using projection. The principle of ultrasonic motor is to use an elliptic motion generated at the side of the vibrator, and the elliptic motion of the ultrasonic motor was obtained by complex oscillation of L$_1$-B$_4$ mode. As the experimental results, the efficiency of linear ultrasonic motor without projection was 1.52[%] when applied voltage was 56[V] in resonance frequency 58.4[kHz]. The efficiency of linear ultrasonic motor using projection was 3.36[%] when applied voltage was 56[V] in resonance frequency 58.4[kHz]. The efficiency was improved by projection.

• Journal of the Korean Operations Research and Management Science Society
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• v.18 no.3
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• pp.101-111
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• 1993

The purpose of this paper is to show the graphic representation of a linear programming problem by a projection method. First, we develop a projection method which conserves the optimality in the projected space, and next we introduce an algorithm to visualize the feasible solution set and the solution process by the projection method. Finally, we give an example to represent a 4-dimensional linear programming problem graphically.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.979-980
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• 2008

In this paper we use the Isometric Projection, a linear subspace method, for manifold representation of the pose-varying-faces. Isometric Projection method for pose identification is evaluated on view varying faces and is compared with other global and local linear subspace methods.

• The Journal of the Korea Contents Association
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• v.9 no.9
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• pp.97-104
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• 2009

This paper describes comparison and analysis of methodology which enables us in order to search the projection technique of optimum for projection in the plane. For this methodology, we applies the high-dimensional facial motion capture data respectively in linear and nonlinear projection techniques. The one core element of the methodology is to applies the high-dimensional facial expression data of frame unit in PCA where is a linear projection technique and Isomap, MDS, CCA, Sammon's Mapping and LLE where are a nonlinear projection techniques. And another is to find out the methodology which distributes in this low-dimensional space, and analyze the result last. For this goal, we calculate the distance between the high-dimensional facial expression frame data of existing. And we distribute it in two-dimensional plane space to maintain the distance relationship between the high-dimensional facial expression frame data of existing like that from the condition which applies linear and nonlinear projection techniques. When comparing the facial expression data which distribute in two-dimensional space and the data of existing, we find out the projection technique to maintain the relationship of distance between the frame data like that in condition of optimum. Finally, this paper compare linear and nonlinear projection techniques to projection high-dimensional facial expression data in low-dimensional space and analyze it. And we find out the projection technique of optimum from it.

• Communications of the Korean Mathematical Society
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• v.19 no.2
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• pp.375-388
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• 2004

For solving symmetric systems of linear equations, it is shown that a new Krylov subspace method can be obtained. The new approach is one of the projection methods, and we call it the projection method for convenience in this paper. The projection method maintains the residual vector like simpler GMRES, symmetric QMR, SYMMLQ, and MINRES. By studying the quasiminimal residual method, we show that an extended projection method and the scaled symmetric QMR method are equivalent.

• Journal of the Korean Data and Information Science Society
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• v.5 no.1
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• pp.1-10
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• 1994

Projection pursuit(PP) is a computer-intensive method which seeks out interesting linear projections of multivariate data onto a lower dimension space by machine. By working with lower dimensional projections, projection pursuit avoids the sparseness of high dimensional data. We show through simulation that two projection pursuit discriminant mothods proposed by Chen(1989) and Huber(1985) do not improve very much the error rate than the existing methods and compare several classification procedures.

• Journal of Korean Foot and Ankle Society
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• v.19 no.4
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• pp.165-170
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• 2015

Purpose: The purpose of this study is to analyze the measurement differences of simple radiographs according to radiation projection angle using a phantom and to propose methods for objective analysis of simple radiographs. Materials and Methods: We took simple radiographs with different projection angles using a C-arm image intensifier and measured five parameters of the foot on the simple radiographic images. Five parameters include lateral tibiocalcaneal angle, lateral talocalcaneal angle, naviculocuboid overlap, lateral talo-first metatarsal angle, and lateral calcaneo-first metatarsal angle. Intraobserver and interobserver reliability were verified, and then intraclass correlations of parameters were analyzed. Results: Radiographic parameters of the foot showed high intraobserver and interobserver reliability. Lateral tibiocalcaneal angle has a strong negative linear relationship with rotation and a moderate negative linear relationship with tilt. Lateral talocalcaneal angle has a moderate positive linear relationship with rotation and a strong positive linear relationship with tilt. Naviculocuboid overlap has a strong positive linear relationship with rotation and a moderate positive linear relationship with tilt. Lateral talo-first metatarsal angle does not have a linear relationship with rotation and a moderate negative linear relationship with tilt. Lateral calcaneo-first metatarsal angle has a moderate positive linear relationship with rotation and tilt. Conclusion: More precise evaluation of the foot with a simple radiograph can be performed by understanding the changes of radiographic parameters according to radiation projection angle.

• Journal of the Korean Mathematical Society
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• v.55 no.2
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• pp.471-506
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• 2018

In this article, some projection methods (or fractional-step methods) are proposed and analyzed for the micropolar Navier-Stokes equations (MNSE). These methods allow us to decouple the MNSE system into two sub-problems at each timestep, one is the linear and angular velocities system, the other is the pressure system. Both first-order and second-order projection methods are considered. For the classical first-order projection scheme, the stability and error estimates for the linear and angular velocities and the pressure are established rigorously. In addition, a modified first-order projection scheme which leads to some improved error estimates is also proposed and analyzed. We also present the second-order projection method which is unconditionally stable. Ample numerical experiments are performed to confirm the theoretical predictions and demonstrate the efficiency of the methods.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.4
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• pp.81-88
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• 2007

The geometry of satellite image captured by linear CCD sensor is different from that of frame camera image. The fact that the exterior orientation parameters for satellite image with linear CCD sensor varies from scan line by scan line, causes the difference of image geometry between frame and linear CCD sensor. Therefore, we need the epipolar geometry for linear CCD image which differs from that of frame camera image. In this paper, we proposed a method of resampling linear CCD satellite image in epipolar geometry under the assumption that image is not formed in perspective projection but in parallel projection, and the sensor model is a 2D affine sensor model based on parallel projection. For the experiment, IKONOS stereo images, which are high resolution linear CCD images, were used and tested. As results, the spatial accuracy of 2D affine sensor model is investigated and the accuracy of epipolar resampled image with RFM was presented.