• The Journal of the Acoustical Society of Korea
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• v.37 no.6
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• pp.489-498
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• 2018

In this paper, a target detection method based on beamspace-domain multichannel nonnegative matrix factorization is studied when an echo of continuous-wave ping is received from a low-Doppler target in reverberant environment. If the receiver of the continuous-wave active sonar moves, the frequency range of the reverberation is broadened due to the Doppler effect, so the low-Doppler target echo is interfered by the reverberation in this case. The developed algorithm analyzes the multichannel spectrogram of the received signal into frequency bases, time bases, and beamformer gains using the beamspace-domain multichannel nonnnegative matrix factorization, then the algorithm estimates the frequency, time, and bearing of target echo by choosing a proper basis. To analyze the performance of the developed algorithm, simulations were performed in various signal-to-reverberation conditions. The results show that the proposed algorithm can estimate the frequency, time, and bearing, but the performance was degraded in the low signal-to-reverberation condition. It is expected that modifying the selection algorithm of the target echo basis can enhance the performance according to the simulation results.

• Journal of Astronomy and Space Sciences
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• v.36 no.3
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• pp.159-168
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• 2019

In solstices during the solar minimum, the hemispheric difference of the equatorial ionization anomaly (EIA) intensity (hereafter hemispheric asymmetry) is understood as being opposite in the morning and afternoon. This phenomenon is explained by the temporal variation of the combined effects of the fountain process and interhemispheric wind. However, the mechanism applied to the observations during the solar minimum has not yet been validated with observations made during other periods of the solar cycle. We investigate the variability of the hemispheric asymmetry with local time (LT), altitude, season, and solar cycle using the electron density taken by the CHAllenging Minisatellite Payload satellite and the global total electron content (TEC) maps acquired during 2001-2008. The electron density profiles provided by the Constellation Observing System for Meteorology, Ionosphere, and Climate satellites during 2007-2008 are also used to investigate the variation of the hemispheric asymmetry with altitude during the solar minimum. During the solar minimum, the location of a stronger EIA moves from the winter hemisphere to the summer hemisphere around 1200-1400 LT. The reversal of the hemispheric asymmetry is more clearly visible in the F-peak density than in TEC or in topside plasma density. During the solar maximum, the EIA in the winter hemisphere is stronger than that in the summer hemisphere in both the morning and afternoon. When the location of a stronger EIA in the afternoon is viewed as a function of the year, the transition from the winter hemisphere to the summer hemisphere occurs near 2004 (yearly average F10.7 index = 106). We discuss the mechanisms that cause the variation of the hemispheric asymmetry with LT and solar cycle.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.293-296
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• 2016

In case of an emergency on a busy road of a city, drivers should make way for special vehicles such as police cars, fire engines, or ambulance as soon as possible. If road infrastructures recognize the movements of special vehicles, and transfer alert message to traffic signal controllers and normal cars through wireless network such as WAVE or TPEG, normal cars can prepare to make way in advance. As a result, it help special vehicles move faster. In this paper, we install a roof mark on the roof of a special vehicle, detect the mark through a mark recognition algorithm which includes perspective transformation, and get the inner information by decoding the digital pattern on it. The experiment results show that mark can be recognized 100% and 93.3% of inner digital data of the mark can be recognized, when the size of a mark is larger than $88cm{\times}88cm$ and the mark moves at a speed of 50km/s.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.30 no.3
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• pp.100-108
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• 2019

Objectives: Adolescence involves a number of developmental processes, as well as unique psychological characteristics and behaviors. An increased rate of internet and game addictions, school violence, and suicide may either represent aspects of adolescence or a psychopathological phenomenon. There is an urgent need to develop software programs that can prevent and resolve adolescent behavioral problems. We applied the mentalization theory to interpret and find solutions for problems faced by adolescent characters in literature. Methods: In Joan Rowling's novel "Casual Vacancy," Sukhvinder is a girl with problems representative of those encountered by modern adolescents; she is a victim of bullying and engages in self-mutilation. We targeted her problematic behaviors as representative of a prementalized state. Results: Born into an upper-class English family with Pakistani origins, Sukhvinder, unlike her siblings, fails her parents' expectations. Whenever she faces a psychological crisis, she regresses into the teleological mode (the most primitive pre-mentalization stage) and regains her sense of self by cutting herself. After her friend's suicide, however, she begins to communicate with her parents and moves toward mentalization. Conclusion: By analyzing Sukhvinder's behavior, we assessed patterns of attachment, empathy, and mentalization, and identified corrective approaches for problematic behaviors. We believe that the presented interpretation may serve as a foundation for the development of models for understanding adolescent deviant behaviors.

• Fire Science and Engineering
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• v.33 no.1
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• pp.92-98
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• 2019

To determine if water-jet nozzle moves and water jetting are effective according to the location of the fire, this study examined the automatic fire-tracking water cannon system and aan indoor hydrant system, such as water jet centered directivity, water jet range maintainability and water jet shape uniformity. First, an examination to find the center of fire accurately from this system design showed that the water jet centered test was accurate. Second, the water jet range test results showed that when water is jetted at the maximum water jet radius, the water jet shows an inaccurate result but within the allowable tolerance range. Finally, the water-jet shape test result confirmed that there are no problems in setting the block from the algorithm design.

• Journal of the Korea Society for Simulation
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• v.28 no.1
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• pp.23-39
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• 2019

The use of drone-bots is demanded in times regarding the reduction of military force, the spread of the life-oriented thought, and the use of innovative technology in the defense through the fourth industrial revolution. Especially, the drone's surveillance and reconnaissance are expected to play a big role in the future battlefield. However, there are not many cases in which the concept of operation is studied scientifically. In this study, We propose search algorithms for reconnaissance drone through simulation analysis. In the simulation, the drone and target move linearly in continuous space, and the target is moving adopting the Random-walk concept to reflect the uncertainty of the battlefield. The research investigates the effectiveness of existing search methods such as Parallel and Spiral Search. We analyze the probabilistic analysis for detector radius and the speed on the detection probability. In particular, the new detection algorithms those can be used when an enemy moves toward a specific goal, PS (Probability Search) and HS (Hamiltonian Search), are introduced. The results of this study will have applicability on planning the path for the reconnaissance operations using drone-bots.

• Cross-Cultural Studies
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• v.50
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• pp.453-482
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• 2018

This study is about the French preposition de. This preposition is considered to have no meaning in the French language, and to have only the grammatical function in its use. This study begins with doubts about such views regarding this preposition. We organize and classify general descriptions of the uses of this preposition. The uses are classified as 'expressing starting point,' 'giving characteristics' and 'performing grammatical functions' and this data is analyzed in terms of the associated cognitive grammar. In the case of expressing the starting point, it is assumed that the trajector moves from the starting point, to the destination point, in the domain of space and in the domain of time. Therefore, it is noted in this case that the preposition de has a dynamic concept. On the other hand, it is significant to understand that the preposition of the 'giving characteristics' defines an outline of a particular class by giving the class's characteristics. The preposition de has a static concept in this case. For the preposition de which introduces the infinitive, all of these dynamic and static concepts are faded and extremely grammaticalized.

• Journal of Convergence for Information Technology
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• v.11 no.1
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• pp.20-27
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• 2021

Eye tracking is one of the NUI technologies, and it finds out where the user is gazing. This technology allows users to input text or control GUI, and further analyzes the user's gaze so that it can be applied to commercial advertisements. In the eye tracking system, the allowable range varies depending on the quality of the image and the degree of freedom of movement of the user. Therefore, there is a need for a method of estimating the accuracy of eye tracking in advance. The accuracy of eye tracking is greatly affected by how the eye tracking algorithm is implemented in addition to hardware variables. Accordingly, in this paper, we propose a method to estimate how many degrees of gaze changes when the pupil center moves by one pixel by estimating the maximum possible movement distance of the pupil center in the image.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.12
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• pp.1726-1733
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• 2019

Movement is everything in life and music is with our whole lives. Based on movement and sound, art has developed and reflected the times with close ties to technology and is creating new cultural content in the digital age. The absence of experts and research institutes with academic knowledge and experience in various fields compared to the frequency with which music and body movements are interwoven in the intermedia art and education of convergence is a real problem. Introducing the Rhythmik that studied the most basic principles of music and exercise through the precedent of foreign universities, we raise the need to introduce music physiology, musicians' Medicine and music performance science, the areas we studied together. It presents a new direction in the convergence era and education in pioneering research areas in which the only "I myself" systematically recognizes the movement to become the subject through physiology and medicine and scientifically moves and expresses music as a medium.

• Journal of Broadcast Engineering
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• v.25 no.6
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• pp.965-972
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• 2020

Depth maps have distance information of objects. They play an important role in organizing 3D information. Color and depth images are often simultaneously obtained. However, depth images have lower resolution than color images due to limitation in hardware technology. Therefore, it is useful to upsample depth maps to have the same resolution as color images. In this paper, we propose a novel method to upsample depth map by shifting the pixel position instead of compensating pixel value. This approach moves the position of the pixel around the edge to the center of the edge, and this process is carried out in several steps to restore blurred depth map. The experimental results show that the proposed method improves both quantitative and visual quality compared to the existing methods.