• Journal of Korea Multimedia Society
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• v.3 no.1
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• pp.53-62
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• 2000

Digital watermarking has been considered as an important technique to protect the copyright of digital content. It is essential that a watermark embedded in a still or moving image resists against various attacks ranging from compression, filtering to cropping. In particular, as JPEG is a dominant still image compression standard for Internet applications, digital watermarking methods that are robust against the JPEG compression are especially required. Most digital watermarking methods proposed so far work by modulating pixels/coefficients without considering the quality level of JPEG, which renders watermarks readily removable. In this paper, we proposed a new digital watermarking method as follows. For providing the robustness against JPEG, the quality level of JPEG is used as parameter on watermarking so as to compute the loss of image caused by JPEG compression and we compute the difference of an original image resulted from JPEG compression. Also in proposed method, we compute the visual components that are derived from the information of edge within image and consideration of brightness discrimination which is one of human visual system's properties. Thus, we proposed new watermarking scheme that after constructing a watermark by considering the loss of image resulted from JPEG compression and visual components derived from the human visual system, the watermark is embedded into the image.

• Journal of Korea Multimedia Society
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• v.16 no.1
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• pp.50-55
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• 2013

This article presents a simple and reasonable in-service, real-time, and continuous single-ended objective video quality assessment model for DTV broadcasting using a multiburst signal at the bottom of the transient effect area, similar to Vertical Interval Test Signals. The issue of in-service video-quality monitoring in DTV broadcasting is addressed, and an effective method of quality monitoring is presented. The proposed method is also implemented and tested in a range of situations using a simulated HDTV broadcasting network.

• Journal of Korea Multimedia Society
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• v.21 no.3
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• pp.415-422
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• 2018

Advances of telecommunication technology bring various changes in journalism field. Reporters started to gather, edit, and transmit content to main server in media company using hand-held smart media and notebook computer. This paper tried to testify valid bit-rate of visual news content using LTE network and mobile phone. Field news like natural disasters need real-time transmission of video content. But broadcasting company normally use heavy ENG system and transmission satellite trucks. We prepared and experimented different types of visual content that has different bit-rates. Transmission tool was LU-60HD mobile system of LiveU Corporation. Transmission result shows that bit-rate of 2Mbps news content is not suitable for broadcasting and VBR (Variable Bit Rate) transmission has better definition quality than CBR (Constant Bit Rate) method. Three different bit-rate of VBR transmission result shows that 5Mbps clip has better quality than 1Mbps and 3Mbps. The higher bit-rate, the better video quality. But if the content has much movements, that cause delay and abnormal quality of video. So optimizing the balance between stability of signal and quality of bit-rate is crucial factor of real-time broadcasting news gathering business.

• Journal of architectural history
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• v.13 no.4 s.40
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• pp.35-54
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• 2004

Perception of architectural experience is different in different culture. This paper aims to identify how the experience of architecture is understood to be different in Eastern and Western culture. The discussion is based on the idea that the Western architecture placed more emphasis on visual perception, while the Eastern, on mutual responsiveness between man and built environment. The fact that the Western culture is more visually oriented than other culture, and therefore visual aspect of architecture, too, is considered to be very important, is already widely agreed among scholars. But, then, what had been considered to be important in the architectural experience in the East? It is the degree and quality of mutual responsiveness between man and architectural environment. This fact influenced much on the making of architecture of course, and the same fact played the key role in making the Eastern architecture different from that of the West. We are so used to the way of architecture of the West, that the quality of responsiveness is unknown if not forgotten. However, it is not the quality that was useful only in traditional society of the East, but necessary in our modem period as well. The quality for responsiveness, therefore, should be rediscovered and restored as the prime value and quality of architecture in the future architecture.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.170-174
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• 2021

The purpose of this study is descriptive survey to quality of life by dry eyes experience in university students. The Korean version of the National eye institute visual functioning questionnaire (NEI-VFQ) was used to evaluate the quality of life. As a result of the study, 18.4% of the participants were diagnosed with dry eyes, and 63.2% experienced subjective dry eyes experience. The findings showed that the factors influencing the visual quality of life was wearing glasses, and the explanatory power for this 13.6%. Further research is needed considering the length of wearing glasses, contact lenses and severity of dry eyes.

• Quality Improvement in Health Care
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• v.5 no.1
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• pp.128-138
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• 1998

Background : There is increased recognition that rigorous approach to functional assessment will complement the assessment of clinical status. This study is to develop the appropriate visual function index in Korean patients with cataracts by the assessment of the reliability, validity of visual function indexes including VF-14. Methods : An prospective study was performed with 92 patients who had undergone either one eye or both eye cataract surgery by 3 ophthalmologists practicing at a university hospital. Patients were interviewed. and clinical data were obtained. Doctors were questioned with self-entered questionnaire forms. Medical record was examined to understand surgery process. The survey was conducted at 1-2 days before cataract surgery. Results : We used following measures : 7 visual function indexes, global measures of patients' trouble and satisfaction with vision, and best-corrected visual acuity(VA) in each eye. 7 visual function indexes showed a high internal consistency reliability (Cronbach's alpha coefficients ${\geq}$ 0.86). The better visual acuity(operated eye, better eye), the higher patient satisfaction with vision, the lower symptom score, the lower patient trouble with vision was correlated with preoperative visual function index scores. Among 7 indexes, VF-12 with the exclusion of 2 items drivings from VF-14 is a high Cronbach's alpha coefficient and correlation coefficient and the highest $R^2$. Conclusion : We conclude that VF-12 is reliable and valid in Korea. So we suggest that in Korea, all items of VF-14, the visual function index, which is in use internationally, ought to be surveyed and VF-12 which has been excluded by 2 items of drivings from VF-14 ought to be used for analysis.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.106-123
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• 2024

This article takes the talk show "Beast Town" as an example to introduce the overall technical solution, technical difficulties and countermeasures for the combination of cartoon virtual characters and virtual studio technology, providing reference and experience for the multi-scenario application of digital humans. Compared with the live broadcast that combines reality and reality, we have further upgraded our virtual production technology and digital human-driven technology, adopted industry-leading real-time virtual production technology and monocular camera driving technology, and launched a virtual cartoon character talk show - "Beast Town" to achieve real Perfectly combined with virtuality, it further enhances program immersion and audio-visual experience, and expands infinite boundaries for virtual manufacturing. In the talk show, motion capture shooting technology is used for final picture synthesis. The virtual scene needs to present dynamic effects, and at the same time realize the driving of the digital human and the movement with the push, pull and pan of the overall picture. This puts forward very high requirements for multi-party data synchronization, real-time driving of digital people, and synthetic picture rendering. We focus on issues such as virtual and real data docking and monocular camera motion capture effects. We combine camera outward tracking, multi-scene picture perspective, multi-machine rendering and other solutions to effectively solve picture linkage and rendering quality problems in a deeply immersive space environment. , presenting users with visual effects of linkage between digital people and live guests.

• Journal of Bio-Environment Control
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• v.6 no.4
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• pp.270-276
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• 1997

This experiment was conducted to develop a practical method to growth in hydroponics conditions. For this purpose, leaf lettuce (Lactuca sativa L., cv. 'Cheongchima') was cultivated under different temperature and light conditions in experimental fields of Sahmyook university from March, 1991 to May, 1996. The visual quality score(VQS), a quantitative parameter to evaluate harvested leaf lettuce quality. The leaf lettuce cultivated at $25^{\circ}C$ solution temperature showed the highest fresh weight pe, plant (59.7g/plant), but lowest visual quality score (5.2), while leaf lettuce cultivated at 15$^{\circ}C$ solution temperature showed lower fresh weight per plant (25.2g/plant) but highest visual quality score (7.2). In general, growth of leaf lettuce was retarded by low solution temperature, but quality was higher than those of other solution temperature. Different day/night temperature of nutrient solutions 20/2$0^{\circ}C$ and 25/2$0^{\circ}C$ was highest in yield, but leaf type was grow longer, and visual quality are inferior to low temperature. Yield was decreased as 10 and 25% at 60 and 80% shading treatment, respectively. Chlorophyll content was decreased by shading. but plant height and root length were increased of leaf lettuce growth with hydroponics.

• Journal of the Korea Computer Graphics Society
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• v.18 no.4
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• pp.1-8
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• 2012

We present improved deformation energy to enhance the visual quality of a shape deformation technique, where we preserve the local structure of an input planar shape. The deformation energy, in general, consists of several constraints such as Laplacian coordinate constraint to preserve the quality of deformed silhouette edges, mean value coordinates and edge length constraints to preserve the quality of deformed internal shape, and user-specified position constraints to control the shape deformation. When the positions of user-specified vertices change, shape deformation techniques compute the positions of the other vertices by means of nonlinear least squares optimization to minimize the deformation energy. When a user-specified vertex changes its position rapidly, it is frequently observed that the visual quality of the deformed shape decrease rapidly, which is mainly caused by unnecessary enlargement of the Laplacian vectors and unnecessary change of the edge directions along the boundary of the shape. In this paper, we propose improved deformation energy by prohibiting the Laplacian and edge length constraints from changing unnecessarily. The proposed deformation energy incorporated with well-known optimization technique can enhance the visual quality of shape deformation along the silhouette and within the interior of the planar shape while sacrificing only a little execution time.

• ETRI Journal
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• v.36 no.3
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• pp.479-489
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• 2014

This paper presents a model-based image steganography method based on Watson's visual model. Model-based steganography assumes a model for cover image statistics. This approach, however, has some weaknesses, including perceptual detectability. We propose to use Watson's visual model to improve perceptual undetectability of model-based steganography. The proposed method prevents visually perceptible changes during embedding. First, the maximum acceptable change in each discrete cosine transform coefficient is extracted based on Watson's visual model. Then, a model is fitted to a low-precision histogram of such coefficients and the message bits are encoded to this model. Finally, the encoded message bits are embedded in those coefficients whose maximum possible changes are visually imperceptible. Experimental results show that changes resulting from the proposed method are perceptually undetectable, whereas model-based steganography retains perceptually detectable changes. This perceptual undetectability is achieved while the perceptual quality - based on the structural similarity measure - and the security - based on two steganalysis methods - do not show any significant changes.