• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.3
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• pp.107-113
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• 2016

Visual discomfort is a common problem in three-dimensional videos. Among the methods to overcome visual discomfort presented in current research, disparity adjustment methods provide little guidance in determining the condition for disparity control. We propose a diaprity adjustment based on the characteristics of disparity distribution on visual comfort, where the visual comfort level is used as the adjustment paramter, in parallax barrier type auto-stereoscopic 3D display. In this paper, we use the horizontal image shift method for disparity adjustment to enhance visual comfort. The speeded-up robust feature is used to estimate the disparity distribution of 3D sequences, and the required amount for disparity control is chosen based on the pre-defined characteristics of disparity distribution on visual comfort. To evaluate the performance of the proposed method, we used a 3D equipment. Subjective tests were conducted at the fixed optimal viewing distance. The results show that comfortable videos were generated based on the proposed disparity adjustment method.

• Journal of the Korea Computer Graphics Society
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• v.25 no.3
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• pp.65-73
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• 2019

Recently commercial mixed-reality devices have be launched and a variety of mixed-reality content has produced, but narrow field of view, which appear to be hardware technical limitations, are mentioned as an important issue for hindering immersion and limiting the scope of use. We propose a new innovative system that cooperate multiple beam projectors and a number of mixed reality devices. Using this technology, users can maximize immersion and minimize frustration of narrow viewing angles through 3D object rendering on background of large 2D screens. This system, named BtS (Beyond the Sight), is implemented on a client-server basis and includes the ability to calibrate between devices, share spatial coordinate systems, and synchronize real-time renderings as core modules. In this paper, each configuration module is described in detail and the possibility of its performance and application is shown through the introduction of mixed reality content case created using BtS system.

• The Journal of the Korean dental association
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• v.57 no.2
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• pp.52-63
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• 2019

Technological advances in contemporary medicine has discovered the causes of countless diseases and recorded a noticeable medical performance. As technology develops, the role of hospitals is expanding to include disease prevention of inpatients, on top of their fundamental role of treating diseases. Recently, hospitals are becoming more influential as they create environments to provide comfort and stability to patients. In this regard, contemporary hospitals are increasingly shifting their focus to create a patient-centric environment as well as develop into humanistic establishments. The same goes to dentists, as well. Since inpatients often have fear and frustration over treatment, hospitals should figure out the environmental factors that are more effective and relaxing for patients and design medical services to provide them. The patients' movement and spaces during their treatment were categorized by stages and collected for gazing information using eye tracking. It analyzed users' gaze information according to Heatmap analysis of distribution and frequency and was determined the presence or absence of stimuli on the components of space. This research is an advanced research to study and enhance treatment environment based on the analysis of patients' gazes. It attempted to create an opportunity to get closer to patient-centric environment by understanding the stimulants and obstacles and controlling the background settings.

• Journal of Broadcast Engineering
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• v.25 no.6
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• pp.882-897
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• 2020

Recently, the use of immersive media contents representing Panorama and 360° video is increasing. Since the viewing angle is limited to generate the content through a general camera, image stitching is mainly used to combine images taken with multiple cameras into one image having a wide field of view. However, if the parallax between the cameras is large, parallax distortion may occur in the stitched image, which disturbs the user's content immersion, thus an image stitching overcoming parallax distortion is required. The existing Seam Optimization based image stitching method to overcome parallax distortion uses energy function or object segment information to reflect the location information of objects, but the initial seam generation location, background information, performance of the object detector, and placement of objects may limit application. Therefore, in this paper, we propose an image stitching method that can overcome the limitations of the existing method by adding a weight value set differently according to the type of object to the energy value using object detection based on deep learning.

• Journal of Broadcast Engineering
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• v.25 no.6
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• pp.836-844
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• 2020

A very large number of pixels is required to generate a computer generated hologram (CGH) with a large-size and wide viewing angle equivalent to that of an analog hologram, which incurs a very large amount of computation. For this reason, a high-performance computing device and long computation time were required to generate high-definition CGH. To solve these problems, in this paper, we propose a technique for generating high-definition CGH by arraying the pre-calculated low-definition CGH and multiplying the appropriately-shifted concave lens function. Using the proposed technique, 0.1 Gigapixel CGH recorded by the point cloud method can be used to calculate 2.5 Gigapixels CGH at a very high speed, and the recorded hologram image was successfully reconstructed through the experiment.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.7
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• pp.2513-2530
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• 2021

With the fast development of information and communication technologies, video streaming services and applications are increasing rapidly. However, the network condition is volatile. In order to provide users with better quality of service, it is necessary to develop an accurate and low-complexity model for Quality of Experience (QoE) prediction of time-varying video. Memory effects refer to the psychological influence factor of historical experience, which can be taken into account to improve the accuracy of QoE evaluation. In this paper, we design subjective experiments to explore the impact of Short-Term Memory (STM) on QoE. The experimental results show that the user's real-time QoE is influenced by the duration of previous viewing experience and the expectations generated by STM. Furthermore, we propose analytical models to determine the relationship between intrinsic video quality, expectation and real-time QoE. The proposed models have better performance for real-time QoE prediction when the video is transmitted in a fluctuate network. The models are capable of providing more accurate guidance for improving the quality of video streaming services.

• Korean Journal of Remote Sensing
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• v.37 no.1
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• pp.161-167
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• 2021

This paper presents the method to quantitatively evaluate the uncertainty of the semi-empirical Bidirectional Reflectance Distribution Function (BRDF) model for Himawari-8/AHI. The uncertainty of BRDF modeling was affected by various issues such as assumption of model and number of observations, thus, it is difficult that evaluating the performance of BRDF modeling using simple uncertainty equations. Therefore, in this paper, Monte-Carlo method, which is most dependable method to analyze dynamic complex systems through iterative simulation, was used. The 1,000 input datasets for analyzing the uncertainty of BRDF modeling were generated using the Second Simulation of a Satellite Signal in the Solar Spectrum (6S) Radiative Transfer Model (RTM) simulation with MODerate Resolution Imaging Spectroradiometer (MODIS) BRDF product. Then, we randomly selected data according to the number of observations from 4 to 35 in the input dataset and performed BRDF modeling using them. Finally, the uncertainty was calculated by comparing reproduced surface reflectance through the BRDF model and simulated surface reflectance using 6S RTM and expressed as bias and root-mean-square-error (RMSE). The bias was negative for all observations and channels, but was very small within 0.01. RMSE showed a tendency to decrease as the number of observations increased, and showed a stable value within 0.05 in all channels. In addition, our results show that when the viewing zenith angle is 40° or more, the RMSE tends to increase slightly. This information can be utilized in the uncertainty analysis of subsequently retrieved geophysical variables.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.12
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• pp.1816-1825
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• 2022

In this paper, we propose a new approach for tracking each human in a surveillance camera network with various resolution cameras. When tracking human on multiple non-overlapping cameras, the traditional appearance features are easily affected by various camera viewing conditions. To overcome this limitation, the proposed system utilizes facial information along with appearance information. In general, human images captured by the surveillance camera are often low resolution, so it is necessary to be able to extract useful features even from low-resolution faces to facilitate tracking. In the proposed tracking scheme, texture-based face descriptor is exploited to extract features from detected face after face frontalization. In addition, when the size of the face captured by the surveillance camera is very small, a super-resolution technique that enlarges the face is also exploited. The experimental results on the public benchmark Dana36 dataset show promising performance of the proposed algorithm.

• Issues in Feminism
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• v.12 no.2
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• pp.69-103
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• 2012

By reviewing relatively recent theory of coercive control, which considers gender as a key concept to conceptualize domestic violence, this article explores battered women's experiences with police responses and institutional law enforcement. Using data and interviews from Korea Women's Hotline, this article analyzes the effects of state intervention which fails to support battered women and sends a message to the community that domestic violence is not such a serious crime. Specifically, this study found some problematic responses and attitudes of police and legal system: first, police is equating domestic violence with physical attacks or serious harms. Second, police and law enforcement personnel blame victims based on her gender performance or gender roles. Third, by individualizing the problem of domestic violence, state intervention ignores important structural factors that cause and perpetuate it. Finally, police and the justice system disempower and discourage battered women by exacerbating victim's fears and risks. Viewing domestic violence as a liberty crime, this study concludes that enhanced understanding of the nature of domestic violence only can contribute to solving the problem and protecting women's human rights.

• Journal of The Korean Astronomical Society
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• v.56 no.2
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• pp.293-299
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• 2023

The Wide-Angle Polarimetric Camera (PolCam) is installed on the Korea's lunar orbiter, Danuri, which launched on August 5, 2022. The mission objectives of PolCam are to construct photometric maps at a wavelength of 336 nm and polarization maps at 461 and 748 nm, with a phase angle range of 0°-135° and a spatial resolution of less than 100 m. PolCam is an imager using the push-broom method and has two cameras, Cam 1 and Cam 2, with a viewing angle of 45° to the right and left of the spacecraft's direction of orbit. We conducted performance tests in a laboratory setting before installing PolCam's flight model on the spacecraft. We analyzed the CCD's dark current, flat-field frame, spot size, and light flux. The dark current was obtained during thermal / vacuum test with various temperatures and the flat-field frame data was also obtained with an integrating sphere and tungsten light bulb. We describe the calibration method and results in this study.