• Korean Journal of Remote Sensing
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• v.29 no.1
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• pp.11-20
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• 2013

Space-borne Synthetic Aperture Radar(SAR) has been one of the most effective tools for monitoring quantitative oceanographic physical parameters. The Doppler information recorded in single-channel SAR raw data can be useful in estimating moving velocity of water mass in ocean. The Doppler shift is caused by the relative motion between SAR sensor and the water mass of ocean surface. Thus, the moving velocity can be extracted by measuring the Doppler anomaly between extracted Doppler centroid and predicted Doppler centroid. The predicted Doppler centroid, defined as the Doppler centroid assuming that the target is not moving, is calculated based on the geometric parameters of a satellite, such as the satellite's orbit, look angle, and attitude with regard to the rotating Earth. While the estimated Doppler shift, corresponding to the actual Doppler centroid in the situation of real SAR data acquisition, can be extracted directly from raw SAR signal data, which usually calculated by applying the Average Cross Correlation Coefficient(ACCC). The moving velocity was further refined to obtain ocean surface current by subtracting the phase velocity of Bragg-resonant capillary waves. These methods were applied to Envisat ASAR raw data acquired in the East Sea, and the extracted ocean surface currents were compared with the current measured by HF-radar.

• The Journal of the Korea Contents Association
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• v.16 no.2
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• pp.633-642
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• 2016

This study looked into Japan's recognition of Korea in early modern era with particular focuses on discourse on Korea and contents in textbooks in those days. In doing so, the topics of nationality, historical recognition, and social aspects in Korea were established and discourse on these topics in educational journals and the contents of textbooks and teaching manuals projected with such discourse were investigated. As for nationality, a strong propensity to negative recognition was clearly observed, represented by the words lazy, enervate, and uncivilized. They defined Korea's history of passive, other-directed nature and described such incompetent national management resulted in negative nationality. Their recognition of Korean history went further away, stating Korea was incapable of maintaining its independence and was a threat to peace of Japan and Asia, hence the forced merger by Japan. The criteria for Japan to assess Korean society were Western civilization and they defined Korean society as a pre-modern society with lower levels of civilization and culture. Discourse in Japan over Korea in early modern era were strongly influenced by Japan's pride as a modern state and its dominating ideology of imperialism and such discussions were spread among students through textbooks and teaching manuals.

• The Journal of the Korea Contents Association
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• v.17 no.11
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• pp.143-155
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• 2017

In the mobile-first era, plenty of mobile apps have been created so that the number of apps owned in a smartphone have been increasing as well. However, users spend most of time with only a few apps and the rest of apps are just kept in their smartphones for future usage. Thus, in order to help users find the apps quickly it is important to study how users arrange apps in a mobile phone screen and find an app. In the literature, we extracted 5 user types to organize mobile apps. We further conducted user survey with 30 subjects and finalized major 3 user types categorized by relatedness(A), aesthetic(B), and external concepts(C). We found that most of subjects took less than 2 minutes when finding frequently-used-apps. However we identified difference in times taken to find a barely-used-apps across three user types; while A type users turns out to be the most effective in finding barely-used-apps, the B type uses tend to be the least effective among three types. For the A type users, an app's name is more important than an icon image because they tend to guess the functionality from the name of the app. The B type users use the color of app icon to find the app in the smartphone. For the C type users who tend to remain the original position of an app when first downloading it in the smartphone, the visibility of an app icon is important to catch users' eyes while they scan a page. The results of this study is expected to be useful for UX designers who improve the usability of app icon usage considering the user types.

• The Journal of the Korea Contents Association
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• v.20 no.5
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• pp.243-250
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• 2020

In the movie <12 Angry Men>, the prejudiced gaze of each jury with the title of "reasonable discussion" or "positive critical rationality" based on the theory of public opinion of Habermas constantly appears. Prejudice is a concept that cannot be judged right or wrong in itself, but as a current social and historical atmosphere, it is judged to be a hindrance to communication in the process of communication and public opinion and often causes social problems. Therefore, in this paper, the concept of prejudice is ultimately investigated by projecting Habermas' theory of public sphere in the movie, looking into the prejudices, and examining the prejudice through the discussion of the jury, that is, the process of resolving the conflict. We are going to draw realistic implications through the mediator of film about how to solve problem of 'prejudice' in the real world. As a result of the study, Habermas' ideal public opinion on the 'consensus for the community' and 'universal rationality' according to the theory of public sphere in Habermas appeared in the film, but partially from the complete prejudice by the 'wall of reality' in the film. It has been found that freedom from prejudice is difficult and that prejudice is a necessary evil in terms of mutual understanding and publicity.

• Journal of The Korean Association For Science Education
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• v.35 no.3
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• pp.383-393
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• 2015

This study analyzed the 6th grade elementary science textbook 'Science stories' reading process of students by utilizing eye movement tracking techniques. Participants read 3 articles in the new experimental science textbooks and solved 9 problems about each article. By understanding and academic achievement results, participants were divided into high-groups, middle-groups, and low-groups. The results of eye movement characteristics of the high-groups and low-groups had the following differences. Number of fixations and number of regressions were higher in high-groups. Average fixation duration and average regressive fixation duration were longer in low-groups. Fixation time for the key sentence of the article was longer in high-groups. Analysis of a scan path and post-interview, high-groups had frequent regression between sentences and they knew where the core of the article is and paid much attention there. In contrast low-groups are sequentially read most articles and some of them had a leap of abnormal range. Problem-solving approach is also different between groups. In conclusion reading style is associated with the science stories comprehension and students who had more regressions, much core search process, effective attention distribution, high concentration showed better understanding results. Also words or sentences used in textbooks are associated with science stories comprehension.

• Journal of Navigation and Port Research
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• v.39 no.1
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• pp.7-13
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• 2015

The number of mobile terminals equipped with a GPS module is steadily increasing today. However, because they using code pseudorange measurements in positioning, the positioning accuracy of mobile terminals is lower than that of those receivers using carrier phases. Especially, the multipath signal causes more significant errors in code pseudoranges. Therefore, the techniques of multipath detection and elimination is necessary. In this study, as an initial analysis of multipath detection and elimination technique development, we tested the feasibility of multipath signal detection using GPS signal strength information. We found that the GPS signal strength increases as the elevation angle gets higher in the open-sky environment. Also, we found that the signal strength decreases when there were some signal reflectors nearby. We checked the repeatability of the signal strength variation characteristics by reflecting repeat time of GPS satellites. As a result, this characteristics repeats almost perfectly when GPS satellites pass the same orbit. Therefore, we found that it is not a temporary phenomenon and the multipath signal detection should be possible by using GPS signal strength information.

• Journal of Astronomy and Space Sciences
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• v.26 no.2
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• pp.229-236
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• 2009

KOorea Multi-purpose SATellite(KOMPSAT)-5 will be launched at 550km altitude in 2010. Accurate satellite position(20 cm) and velocity(0.03 cm/s) are required to treat highly precise Synthetic Aperture Radar(SAR) image processing. Ionosphere delay was eliminated using dual frequency GPS data and double differenced GPS measurement removed common clock errors of both GPS satellites and receiver. SAC-C carrier phase data with 0.1 Hz sampling rate was used to achieve precise orbit determination(POD) with ETRI GNSS Precise Orbit Determination(EGPOD) software, which was developed by ETRI. Dynamic model approach was used and satellite's position, velocity, and the coefficients of solar radiation pressure and drag were adjusted once per arc using Batch Least Square Estimator(BLSE) filter. Empirical accelerations for sinusoidal radial, along-track, and cross track terms were also estimated once per revolution for unmodeled dynamics. Additionally piece-wise constant acceleration for cross-track direction was estimated once per arc. The performance of POD was validated by comparing with JPL's Precise Orbit Ephemeris(POE).

• Journal of KIISE
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• v.42 no.5
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• pp.609-620
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• 2015

Viewers of videos are likely to absorb more information from the part of the screen that attracts visual attention. This fact has led to the visual attention models that are being used in producing and evaluating videos. In this paper, we investigate the factors that are significant to visual attention and the mathematical form of the visual attention model. We then estimated the visual attention probability using the statistical design of experiments. The analysis of variance (ANOVA) verifies that the motion velocity, distance from the screen, and amount of defocus blur affect human visual attention significantly. Using the response surface modeling (RSM), we created a visual attention score model that concerns the three factors, from which we calculate the visual attention probabilities (VAPs) of image pixels. The VAPs are directly applied to existing gradient based 3D effect perception measurement. By giving weights according to our VAPs, our algorithm achieves more accurate measurement than the existing method. The performance of the proposed measurement is assessed by comparing them with subjective evaluation as well as with existing methods. The comparison verifies that the proposed measurement outperforms the existing ones.

• Atmosphere
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• v.29 no.1
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• pp.105-112
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• 2019

Measurements of vertical air motion and microphysics are essential for improving our understanding of convective clouds. In this paper, the author reviews the current research on the retrieval of vertical air motions using the cloud radar. At radar wavelengths of 3 mm (W-band radar; 94-GHz radar; cloud radar), the raindrop backscattering cross-section (${\sigma}b$) varies between successive maxima and minima as a function of the raindrop diameter (D) that are well described by Mie theory. The first Mie minimum in the backscattering cross-section occurs at D~1.68 mm, which translates to a raindrop terminal fall velocity of ${\sim}5.85m\;s^{-1}$ based on the Gunn and Kinzer relationship. Since raindrop diameters often exceed this size, the signal is captured in the radar Doppler spectrum, and thus, the location of the first Mie minimum can be used as a reference for retrieving the vertical air motion. The Mie technique is applied to radar Doppler spectra from the surface-based and airborne, upward pointing W-band radars. The contributions of aircraft motion to the vertical air motion are also described and further the first-order aircraft motion corrected equation is presented. The review also shows that the separate spectral peaks due to the cloud droplets can provide independent validation of the Mie technique retrieved vertical air motion using the cloud droplets as a tracer of vertical air motion.

• Industry Promotion Research
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• v.6 no.2
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• pp.37-46
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• 2021

The purpose of this study is to examine the necessity of providing new perspectives by conveying the various psychological changes and realities experienced by victims of incest sexual violence after the incident, And it is meaningful to understand and record it through. The results of the analysis through the phenomenological methodology are as follows: First, participants were disturbed by the emotional neglect of their parents and forced violence, threats, and silence by their family members, resulting in disbelief in interpersonal relationships and low self-esteem and suffered constant difficulties in daily life. Second, the suffering and aftereffects of sexual violence experienced the conflict of roles by repeating the real maladjustment and social activity avoidance as the fear of being informed about the event, the negative thought about oneself, and the difficulty of interpersonal relationship. Third, the aftereffects of incest sexual violence in childhood·adolescence were found to be extreme with regard to PTSD. The PTSD experience has become a factor that forces participants to rely on substances, such as psychiatric medications and alcohol, and further avoids external activities with hallucinations and delusions. Fourth, the change through the adaptation process is a new perspective on life, facing and separating the events. During the adaptation program, they tried to express their words and feelings that they could not express because of the past hurts, to set goals for living their life, and to move forward. The experience of overcoming reality has enhanced participants' confidence in self-esteem, self-efficacy, and healthy self-control ability. In this study, it is meaningful to suggest a model in which the incest sexual violence trauma is reexperienced through the new daily crisis and the new adaptation process is repeated for each process.