• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.5
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• pp.518-528
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• 2014

In this paper, we propose a method to recognize the action direction of human by developing 4D space-time (4D-ST, [x,y,z,t]) features. For this, we propose 4D space-time interest points (4D-STIPs, [x,y,z,t]) which are extracted using 3D space (3D-S, [x,y,z]) volumes reconstructed from images of a finite number of different views. Since the proposed features are constructed using volumetric information, the features for arbitrary 2D space (2D-S, [x,y]) viewpoint can be generated by projecting the 3D-S volumes and 4D-STIPs on corresponding image planes in training step. We can recognize the directions of actors in the test video since our training sets, which are projections of 3D-S volumes and 4D-STIPs to various image planes, contain the direction information. The process for recognizing action direction is divided into two steps, firstly we recognize the class of actions and then recognize the action direction using direction information. For the action and direction of action recognition, with the projected 3D-S volumes and 4D-STIPs we construct motion history images (MHIs) and non-motion history images (NMHIs) which encode the moving and non-moving parts of an action respectively. For the action recognition, features are trained by support vector data description (SVDD) according to the action class and recognized by support vector domain density description (SVDDD). For the action direction recognition after recognizing actions, each actions are trained using SVDD according to the direction class and then recognized by SVDDD. In experiments, we train the models using 3D-S volumes from INRIA Xmas Motion Acquisition Sequences (IXMAS) dataset and recognize action direction by constructing a new SNU dataset made for evaluating the action direction recognition.

• Journal of The Korean Association For Science Education
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• v.33 no.1
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• pp.193-207
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• 2013

The purpose of this study was to investigate middle school and science-gifted students' conceptions about motion of objects on the surface of the earth and the moon. The subjects were 61 first-, 51 second-, 51 third-year students, for a total of 163 in a middle school and 32 science-gifted students from a university-affiliated sciencegifted education center for secondary school students. The research contents were conceptions about motion of objects by the vertical direction, an inclined plane and horizontal plane on the surface of the earth and the moon. The questions were as follows: If two balls, same size but different mass, were put on, thrown over, by the vertical direction, an inclined plane and a horizontal plane on the surface of the earth and the moon at the same time and speed, which one would arrive faster than the other?; In the same mass in the earth and the moon, how fast could the object reach to which location, the earth or the moon? The results showed that science-gifted students offer meaningful difference on the concept of objects in motion at the vertical direction, an inclined plane and a horizontal plane on the earth and at the vertical direction on the moon than general middle school students. There were meaningful difference on the vertical up direction, an inclined plane and a horizontal plane in the same situation in the earth and the moon. Finally, based on the results of our study, we discuss possible educational implications for teaching the concept of objects in motion.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.5
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• pp.1109-1122
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• 1996

Generally, moving images contain the various components in motions, which reange from a static object and background to a fast moving object. To extract the accurate motion parameters, we must consider the various motions. That requires a wide search egion in motion estimation. The wide search, however, causes a high computational complexity. If we have a few knowledge about the motion direction and magnitude before motion estimation, we can determine the search location and search window size using the already-known information about the motion. In this paper, we present a local adaptive motion estimation approach that predicts a block motion based on spatio-temporal neighborhood blocks and adaptively defines the search location and search window size. This paper presents a technique for reducing computational complexity, while having high accuracy in motion estimation. The proposed algorithm is introduced the forward and backward projection techniques. The search windeo size for a block is adaptively determined by previous motion vectors and prediction errors. Simulations show significant improvements in the qualities of the motion compensated images and in the reduction of the computational complexity.

• Journal of Navigation and Port Research
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• v.38 no.6
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• pp.683-688
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• 2014

The vessel should prevent dragging anchor against the external forces by utilizing the anchor and secure the stability of it. A fundamental understanding on the embedding motion and holding power of the anchor is necessary to perform the safe operating of anchor work. In this study, the embedding motion and holding power of the anchor according to an initial position in an experimental tank of 6m long in sand are tested by using two types of different anchor models(ASS and AC-14), which are generally applied to the commercial vessel nowadays. The anchor flukes seem to rotate and to be embedded into soil up to the maximum depth and maintaining a constant depth in case of the same direction and perpendicular to the towing direction, regardless of the form of an anchor. In case of the opposite direction to the towing direction, it is noted that the coefficient of holding power becomes smaller than the other initial positions.

• Journal of Fashion Business
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• v.19 no.3
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• pp.130-143
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• 2015

By studying 3-D virtual human modeling, motion-capturing and clothing simulation for easier and safer work clothes development, this research aimed (1) to categorize heavy manufacturing work motions; (2) to generate a 3-D virtual male model and establish painting work motions within a 3-D virtual clothing simulation system through computerized body scanning and motion-capturing; and finally (3) to suggest simulated clothing images of painting work clothes developed based on virtual male avatar body measurements by implementing the work motions defined in the 3-D virtual clothing simulation system. For this, a male subject's body was 3-D scanned and also directly measured. The procedures to edit a 3-D virtual model required the total body shape to be 3-D scanned into a digital format, which was revised using 3-D Studio MAX and Maya rendering tools. In addition, heavy industry workers' work motions were observed and recorded by video camera at manufacturing sites and analyzed to categorize the painting work motions. This analysis resulted in 4 categories of motions: standing, bending, kneeling and walking. Besides, each work motion category was divided into more detailed motions according to sub-work posture factors: arm angle, arm direction, elbow bending angle, waist bending angle, waist bending direction and knee bending angle. Finally, the implementation of the painting work motions within the 3-D clothing simulation system presented the virtual painting work clothes images simulated in a dynamic mode.

• Journal of Wind Energy
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• v.14 no.4
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• pp.87-97
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• 2023

Due to the limitations of onshore wind power, the wind power industry is currently transitioning to offshore wind power. There has been active research on the development of a floating LiDAR system (FLS) that is easy to install at a low cost. The Carbon Trust published a commercialization roadmap for FLS in 2013, and an updated version was released in 2018, taking into account industry experience. The roadmap divides the development maturity of FLS into three stages: Stage 1 (prototype), Stage 2 (pre-commercialization), and Stage 3 (commercialization), each of which requires availability and accuracy assessment. The results must meet the requirements of the Key Performance Index (KPI) for each stage. Therefore, when developing FLS, the motion compensation algorithm of the FLS is essential because the LiDAR can produce incorrect measurements of wind speed and direction due to the six degrees of freedom in motion. In this study, we implemented the FLS motion compensation algorithm developed by Nassif, F.B. et al. and validated it using data provided by Fraunhofer. In conclusion, the results showed that the determination coefficients of wind speed and wind direction were improved compared to those obtained from the met mast.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2685-2688
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• 2003

A PC-based system for both monitoring and controlling SAUV is developed. The developed system is located on a ship and communicate with the SAUV through optical link through which the system sends motion command and receives video data, SSBL and Digital I/O data. The motion command includes velocity data and direction data. The overall system is developed with the intention of easy operation for operator and safe motion of SAUV. The easy operation is realized by GUI-based interface and the safe motion is realized by fault tolerant capability.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.4 no.3
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• pp.58-66
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• 1995

It is very important to test motion accuracy and performance of NC machine tools as they affect that of all other machines machined by them in industry. In this paper, in has become possible to detect errors of linear displacement of radial direction for circular motion test using newly assembled magnetic type of linear scales so called Magnescale ball bar system, and to calculate time interval getting error motion data and revolution angle of circular motion in machining center using tick pulses come out from computer. And a set of error data gotten from test is expressed to a plot by computer treatment and to numerics of error motion by statistical treatment and results of test are compared with those of Renishaw ball bar system.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.161-163
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• 2005

In this paper, we propose an efficient motion vector recovery algorithm for the new coding standard H.264, which makes use of the Lagrange interpolation formula. In H.264/AVC, a 16$\times$16 macroblock can be divided into different block shapes for motion estimation, and each block has its own motion vector. In the natural video the motion vector is likely to move in the same direction, hence the neighboring motion vectors are correlative. Because the motion vector in H.264 covers smaller area than previous coding standards, the correlation between neighboring motion vectors increases. We can use the Lagrange interpolation formula to constitute a polynomial that describes the motion tendency of motion vectors, and use this polynomial to recover the lost motion vector. The simulation result shows that our algorithm can efficiently improve the visual quality of the corrupted video.

• Bulletin of the Society of Naval Architects of Korea
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• v.21 no.1
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• pp.3-12
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• 1984

Up to now, it has been common to treat the maneuvering motion of a ship as a 3-degree-freedom motion i.e. surge, sway and yaw on the sea surface, for the simplicity and mathematical calculation, and it is quite acceptable in the practical point of view. Meanwhile, considering the maneuverability of a ship under the special conditions such as in irregular waves, in wind or at high speed with small GM value, it is required that roll effect must be considered in the equation of ship motion. In this paper the author tried to build up the 4-degree-freedom motion equation by adding roll. And then, applying the M.M.G.'s mathematical model and with captive model test results the roll-coupled hydrodynamic derivatives were found. With these the author could make some simulating program for turning and zig-zag steering. Through the computer simulations, the effect of roll to the ship maneuver became clear. The effect of the wind force to the maneuverability was also found. Followings are such items that was found. 1) When roll is coupled in the maneuvering motion, the directional stability becomes worse and the turning diameter becomes smaller as roll becomes smaller as roll becomes larger. 2) When maneuver a ship in the wind, the roll becomes severe and the directional stability becomes worse. 3) When a ship turns to the starboard side, the wind blowing from 90 degree direction to starboard causes the largest roll and the largest turning diameter, and the wind from other direction doesn't change the turning diameter. 4) When a ship is travelling with a constant speed with rudder amidship, if steady wind blows from one direction, the ship turns toward that wind. This phenomenon is observed in the actual seaways.