• Nuclear Engineering and Technology
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• v.20 no.2
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• pp.132-136
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• 1988

A strategic question in groundwater contaminant transport modeling is whether we need to treat waste packages or drums as individual, discrete sources or as approximately lumped sources. In this paper we present analyses of array sources in porous media. We analyze a planar array of sources in porous media with groundwater flow. We compare the concentration field predicted by a detailed model of individual point sources to concentration fields predicted by an infinite plane source and a single point source, all of the same equivalent strength. From this study we identified three regions: (1) a region close to the sources where the effects of adjacent sources are significant and individual source models should be used, (2) a region extending from a few meters to hundreds to thousands of meters downstream, where an equivalent source of infinite extent gives accurate results, and (3) a far-field region, where in an equivalent source of finite extent gives accurate results.

• Journal of Broadcast Engineering
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• v.26 no.3
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• pp.321-326
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• 2021

Blockchain is increasing in value as a platform for safe transmission of capital transactions or secure data. In addition, blockchain has the potential as a new platform that can safely store large amounts of data such as videos, music, and photos, and safely manage transaction details and service usage specifications. Since it is not possible to store large-capacity media data in a block, research on the performance of storing sound source information in a block and retrieving the stored sound source data by using the distributed storage system (IPFS) and the hash information of the sound source signature data was conducted. In this paper, we propose a sound source signature indexing method using a bloom filter that can improve the search speed suggested by previous studies. As a result of the experiment, it was confirmed that improved search performance (O(1)) than the existing search performance (O(n)) can be achieved.

• Asia pacific journal of information systems
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• v.20 no.2
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• pp.103-124
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• 2010

Social communications using information and communication technologies (ICT) for social interactions have been making a significant impact on task performance in organizations. However, most of the existing studies on ICT (e.g., telephone and email) have only focused on technical improvement of communication efficiencies (e.g., information exchange and storage). In this paper, we claim that ICT may be another alternative source of knowledge creation that enables employees to work, find solutions, and achieve their goals faster and better. We investigate the impact of ICT in terms of both tasks and social aspects with knowledge creation as task performance. Also, we investigate the moderating effect of media synchronicity on these relationships. This study contributes to the understanding of contemporary communications media usage and its performance in organizations. We collected and analyzed survey data of 248 company employees, using PLS. The results indicate that task urgency and social influence directly affect ICT usage, and even knowledge creation. Also the media synchronicity moderates the relationship between the characteristics of a given task and ICT usage and the relationship between ICT usage and knowledge creation. Theoretical and practical implications of these findings are also discussed in the paper.

• Hwankyungkyoyuk
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• v.9 no.1
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• pp.30-38
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• 1996

The purpose of this study was to survey on the awareness of teachers and students to mass media as a source for school environmental education. This study was performed with the questionnaire to 179 teachers who participated in certificate in-service training for $\ulcorner$Environment$\lrcorner$subject and to 635 students(primary: 177, middle: 179, high school students: 279). The results derived from this study were as follows: First, most teachers(86.6%) evaluated that mass media's effects on students were high and positive in terms of school environmental education, thus they thought that the application necessity and possibility of mass media for environmental education were so too. Second, many teachers evaluated that more program related with environment had to be produced(57.0%) and disseminated, and information on them had to be apprised teachers to activate school environmental education(44.1%). Third, both teachers(87.1%) and students(70.4%) evaluated that audio-visual media such as television, video, movie was better than others for environmental education because audio-visual media could be more realistic and dynamic(T: 48.0%, S: 41.7%). Fourth, we found that as the result of statistical analysis, students's friendliness. credibility and preference on media were different to school classes. But we could not analize the relationship between factors for the limit of sample.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.415-424
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• 2011

This research was conducted to verified the effectiveness of a sintered porous media coated with organic matter as nutrient source and microorganisms as decomposer effective in TPH decomposition for a closed-typed biopole system. The organic matter content in the sintered porous media which was developed with bentonite increased with increasing dilution ratio of pig slurry and the sintered porous media as well as decrease in the particle size of sintered porous media. The decomposition rate of TPH was significantly increased with increasing aeration than that under atmospheric condition. Also the sintered porous media containing organic matter and microorganisms proved that the decomposition was enhanced with addition of nutrients sources in addition to aeration periodically.

• Journal of Information Science Theory and Practice
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• v.11 no.4
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• pp.1-13
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• 2023

Being one of the first and hardest hit countries by the coronavirus, Iran still continues to preserve its place among nations with the highest rates of infection and COVID-19 related deaths. While on the surface, such worrying status evinces the failure of the authorities in handling the crisis, at deeper levels, it points to the fundamentalist nature of the government and political system of the country. In this view, the current devastating condition in Iran is a clear indication of the all-out influence of the Islamic regime's ideologies on officials' decision-making and their political agendas throughout the pandemic. Accordingly, the staterun mainstream media, as the most preeminent institution of power, have been incessantly engaged in disseminating a series of ideology-laden information around the issues concerning the coronavirus, and in line with the developing political discourses during pandemic. Far from being based on factual accounts or scientific facts, these disseminated messages inevitably grew into a source of disinformation, ultimately resulting in overall public confusion and skepticism. Through examining the data gathered from some of the most prominent online news agencies run by the government, this study identifies five major discursive trends through which the mainstream media propagated ambiguous and manipulative information about COVID-19. These findings are then explained in the light of media system dependency theory, leading to the argument that within autocratic nation-states, public reliance on media during a national/global crisis brings about new opportunities for state exploitation, and further distressing consequences for the people.

• Journal of the Korea Computer Graphics Society
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• v.17 no.2
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• pp.11-16
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• 2011

In computer graphics, shadows play a very important role as a hint of inter-object distance as well as themselves in terms of realism. To represent shadows, some traditional methods such as shadow mapping and shadow volume have been frequently used for the purpose. However, the rendering results are not natural since they assume the point light. On the contrary, an area light can render soft-shadows, but its computation is too burdensome due to integral over the whole light source surface. Many alternatives have been introduced, back-projection of occluder onto the light source to get visibility of light or filtering of shadow boundary by calculating size of penumbra. But they also have problems of light bleeding or ringing effects because of low order approximation, or low performance. In this paper, we describe a method to improve those problems using shadow atlas.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.3
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• pp.1228-1248
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• 2020

Steganalysis & steganography have witnessed immense progress over the past few years by the advancement of deep convolutional neural networks (DCNN). In this paper, we analyzed current research states from the latest image steganography and steganalysis frameworks based on deep learning. Our objective is to provide for future researchers the work being done on deep learning-based image steganography & steganalysis and highlights the strengths and weakness of existing up-to-date techniques. The result of this study opens new approaches for upcoming research and may serve as source of hypothesis for further significant research on deep learning-based image steganography and steganalysis. Finally, technical challenges of current methods and several promising directions on deep learning steganography and steganalysis are suggested to illustrate how these challenges can be transferred into prolific future research avenues.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.203-206
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• 2009

This paper represents an efficient algorithm to segment objects from the background using multiple images of distinct luminous intensities. The proposed algorithm obtains images with different luminous intensities using a camera flash. From the multiple intensities for a pixel, a saturated luminous intensity is estimated together with the slope of intensity rate. Then, we measure the sensitivities of pixels from their slopes. The sensitivities show different patterns according to the distances from the light source. Therefore, the proposed algorithm segments near objects using the sensitivity information by minimizing an energy function. Experimental results on various objects show that the proposed algorithm provides accurate results without any user interaction.

• Atmosphere
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• v.24 no.2
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• pp.253-263
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• 2014

The Korea Meteorological Administration has recently focused on the promotion of the meteorological industry in the private sector. Broadcast meteorology has provided the main source of income to the Meteorological industry in the United States with The Weather Channel (TWC) being the most prominent enterprise. TWC has 31 years of history and has become an icon of innovation in the U.S. meteorological industry. TWC's success story was reviewed for the possible adaptation of Korea's meteorological media industry. Expected roles for public, academic, and private sectors were suggested for boosting industrial meteorology for the media at present and in the future.