• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.3
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• pp.176-184
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• 1998

We present a sequential factorization method using singular value decomposition (SVD) for recovering both the three-dimensional shape of an object and the motion of camera from a sequence of images. We employ paraperpective projection [6] for camera model to handle significant translational motion toward the camera or across the image. The proposed mthod not only quickly gives robust and accurate results, but also provides results at each frame becauseit is a sequential method. These properties make our method practically applicable to real time applications. Considerable research has been devoted to the problem of recovering motion and shape of object from image [2] [3] [4] [5] [6] [7] [8] [9]. Among many different approaches, we adopt a factorization method using SVD because of its robustness and computational efficiency. The factorization method based on batch-type computation, originally proposed by Tomasi and Kanade [1] proposed the feature trajectory information using singular value decomposition (SVD). Morita and Kanade [10] have extenened [1] to asequential type solution. However, Both methods used an orthographic projection and they cannot be applied to image sequences containing significant translational motion toward the camera or across the image. Poleman and Kanade [11] have developed a batch-type factorization method using paraperspective camera model is a sueful technique, the method cannot be employed for real-time applications because it is based on batch-type computation. This work presents a sequential factorization methodusing SVD for paraperspective projection. Initial experimental results show that the performance of our method is almost equivalent to that of [11] although it is sequential.

• The Journal of the Korea Contents Association
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• v.10 no.3
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• pp.1-9
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• 2010

In this paper, we propose a new method of improving accuracy of motion estimation in mobile environments, compared with Rosten's algorithm. The present method selects corners as feature points. The Rosten's algorithm uses simple addition and subtraction to detect the corners. Although it has the advantage of faster processing speed, Rosten's algorithm has a drawback of low performance in motion estimation. We use the NCC(Normalized Cross Correlation) coefficients to match the corners, and remove in two steps the outliers of inaccurate matching corners. We compare the proposed algorithm with Rosten's algorithm by applying both to the real images. We find that the proposed method shows better performance than Rosten's algorithm in motion estimation. In addition, we implement the present method on mobile devices and confirm that it works in mobile environments in real time.

• Journal of Astronomy and Space Sciences
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• v.22 no.4
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• pp.513-526
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• 2005

The objectives of this study are to perform extensive analysis on internal mass motion for a wider parameter space and to provide suitable design criteria for a broader applicability for the class of spinning space vehicles. In order to examine the stability criterion determined by a perturbation method, some numerical simulations will be performed and compared at various parameter points. In this paper, Ince-Strutt diagram for determination of stable-unstable regions of the internal mass motion of the spinning thrusting space vehicle in terms of design parameters will be obtained by an analytical method. Also, phase trajectories of the motion will be obtained for various parameter values and their characteristics are compared.

• Korean Journal of Applied Biomechanics
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• v.17 no.1
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• pp.175-184
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• 2007

The first purpose of this study was to compare kinematic variables during spinning motion with or without upper extremity and identify the most effective spinning method. The second purpose of this study was to compare functional difference between novice and elite dancers with the term of training. Ten experienced female dancers and ten novices were recruited as subjects for this study. Elite group was asked to perform turn motion with three types of upper extremity. Novice group has taken training of spotting technique for five weeks. Four Falcon HiRES cameras were used to analyze kinematic variables including head angular velocity and CG displacement during spinning. These data were sampled before training, after 3-week, and 5-week of training. Eight different events in two consecutive turns were defined for statistical comparison. One-way ANOVA was performed to compare among the kinematics of turning motion with three types of upper extremity. Independent t-test also used to compare kinematics between elite and novice at three different length of training. As results, spinning with both arm increased angular velocity and stability compared to the turning motion with one arm or with arm strapped and found out that the turn with both arm was the most effective way of spin. Also, for novice dancers, three weeks of training were needed to complete spinning motion.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.2
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• pp.114-126
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• 2009

The authors adopt the Unmanned Undersea Vehicle(UUV), which has taken the shape of manta(Sohn et al. 2006). They call here it Manta-type Unmanned Undersea Test Vehicle(MUUTV). MUUTV is based on the same design concept as UUV called Manta Test Vehicle, which was originally built and operated by the Naval Undersea Warfare Center(Lisiewicz and French 2000, Sirmalis et al. 2001). In order to evaluate manoeuvring motion characteristics of MUUTV, numerical simulation technique has been utilized. Previous mathematical model on manoeuvring motion of MUUTV(Sohn et al. 2006) is basically adopted. Result of static experiment carried out in circulating water channel and a part of NSRDC standard model(Feldman 1979) on rotational mode are supplemented. Some of the hydrodynamic derivatives are obtained from model experiment in circulating water channel and the rest of them are estimated.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.4
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• pp.301-314
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• 1990

This paper is an attempt to use vision-pattern recognition technique to analyzation on a hidden rigid body motion. Specially shaped rod, rigidly connected to the hidden body is extended to the ouside of hiding object so that a camera may catch the motion data. Every motion can be described with translatio and rotation. But translation can be explanied with ratation with a infinitly far centroid. Motion analysis is to find the instantaneous centroid and ratation angle. With this theory jaw motion is analyzed in this paper.

• Journal of Sensor Science and Technology
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• v.17 no.6
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• pp.447-453
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• 2008

Respiration rate is one of the important vital signs. Photo-plethysmography (PPG) measurement especially on a finger has been widely used in pulse oximetry and also used in estimating respiration rate. It is well known that PPG contains respiration-induced intensity variation (RIIV) signal. However, the accuracy of finger PPG method has been controversial. We introduced a new technique of enhancing motion artifact by respiration. This was achieved simply by measuring PPG on the thorax. We examined the accuracy of these two PPG methods by comparing with two existing methods based on thoracic volume and nostril temperature changes. PPG sensing on finger tip, which is the most common site of measurement, produced 6.1 % error. On the other hand, our method of PPG sensing on the thorax achieved 0.4 % error which was a significant improvement. Finger PPG is sensitive to motion artifact and it is difficult to recover fully small respiratory signal buried in waveform dominated by absorption due to blood volume changes. Thorax PPG is poor to represent blood volumes changes since it contains substantial motion artifact due to respiration. Ironically, this inferior quality ensures higher accuracy in terms of respiration measurement. Extreme low-cost and small-sized LED/silicon detector and non-constrained reflection measurement provide a great candidate for respiration estimation in ubiquitous or personal health monitoring.

• Journal of Korean Port Research
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• v.6 no.2
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• pp.33-42
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• 1992

In this paper we investigate the motion response of a moored ship in the fluid region sheltered by inclined breakwaters. The matched asymptotic expansion technique is employed to analyze the wave fields scattered by the inclined breakwaters. Fluid domain is subdivided into the ocean, entrance and sheltered regions. Unknown coefficients contained in each region can be determined by matching at the intermediate zone between two neighboring regions. The wave field generated by the ship motion can be analyzed in terms of Green's function method. To obtain the velocity jump across the ship associated with the symmetric motion modes, the sheltered region is further divided into near field of the ship and the rest field. The image method is introduced to consider the effect of the pier near the ship. The integral equation for the velocity jump is derived by the flux matching between the inner region and the outer region of a moored ship. Throughout the numerical calculation it is found that the inclined angle width of entrance of breakwaters as well as the location of moored vessel play an important role in the motion response of a moored ship.

• PNF and Movement
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• v.21 no.3
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• pp.319-326
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• 2023

Purpose: The purpose of this study was to investigate the effects of modified ankle movement patterns on participants' active dorsiflexion range of motion and leg muscle activity. Methods: This study recruited twenty-five participants, all of whom were healthy individuals with no abnormalities in the ankle or knee joints. The research methodology involved measuring the active dorsiflexion range of motion and muscle activity in each person's legs based on the presence or absence of toe extension while the subjects were in a comfortable, supine position. A statistical analysis was conducted using SPSS 25.0, and a paired samples t-test was employed. The significance level was set at 0.05. Results: When the participants demonstrated the modified ankle movement pattern with a controlled toe grip, there was an increase in their active dorsiflexion angle. However, during the proprioceptive neuromuscular facilitation technique without a controlled toe grip, a higher level of activity was observed in the leg muscles. Conclusion: The results of this study could be used as foundational data for establishing a rehabilitation exercise program designed to enhance range of motion and muscle activation in the ankle joint.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.3
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• pp.221-229
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• 2013

In this paper, the image formation by the motion compensation technique for Synthetic Aperture Radar system(SAR) were realized through the computer simulation. The motion compensation technique performed image data with the range compression, the compensation procedure, the azimuth compensation and the noise elimination procedure. The range compression procedure transform the SAR raw data into the frequency domain and correlate with the range reference function and then inversely transform into the time domain. The compensation procedure contain the aircraft fluctuations compensation and the radar image degrading effect elimination procedure which was caused by image formation algorithm itself. The aircraft fluctuations compensation procedure perform the first stage which correct the phase angle and the second stage which calculate the Doppler frequency and determine the coordinate of the received signal. The radar image degrading effect elimination procedure also perform range migration compensation and the image defocussing effect compensation. The azimuth compression procedure transform the compensation data to the frequency domain and correlate with the azimuth reference function. The azimuth correlated data are inversely transformed to the time domain which is called SAR image data. When the above procedure were completed, the image data contains the received signals mixed with noise. The threshold technique was applied to elimination the noise from the mixed image data.