• Journal of Powder Materials
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• v.24 no.4
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• pp.308-314
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• 2017

$Fe_3O_4$/Fe/graphene nanocomposite powder is synthesized by electrical wire explosion of Fe wire and dispersed graphene in deionized water at room temperature. The structural and electrochemical characteristics of the powder are characterized by the field-emission scanning electron microscopy, X-ray diffraction, Raman spectroscopy, field-emission transmission electron microscopy, cyclic voltammetry, and galvanometric discharge-charge method. For comparison, $Fe_3O_4$/Fe nanocomposites are fabricated under the same conditions. The $Fe_3O_4$/Fe nanocomposite particles, around 15-30 nm in size, are highly encapsulated in a graphene matrix. The $Fe_3O_4$/Fe/graphene nanocomposite powder exhibits a high initial charge specific capacity of 878 mA/g and a high capacity retention of 91% (798 mA/g) after 50 cycles. The good electrochemical performance of the $Fe_3O_4$/Fe/graphene nanocomposite powder is clearly established by comparison of the results with those obtained for $Fe_3O_4$/Fe nanocomposite powder and is attributed to alleviation of volume change, good distribution of electrode active materials, and improved electrical conductivity upon the addition of graphene.

• Journal of Broadcast Engineering
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• v.5 no.1
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• pp.102-112
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• 2000

The previous video structuring techniques are mainly limited to shot or shot group level. However, the shot level structure couldn't provide semantics within a video. So, researches on high level structuring are going on for getting over the drawbacks of shot level structure, recently. To overcome the drawbacks of shot level structure, we propose video scene segmentation technique based on color and motion features. For considering various color distribution, each shot is divided into sub-shots based on color feature. A key frame is extracted from each sub-shot. The motion feature in a shot is extracted from MPEG-1 video's motion vector. Moreover adaptive weights based on motion's property in search range are applied to color and motion features. The experiment results of proposed technique show the excellence in view of the over-segmentation and the reflection of semantics, comparing with those of previous techniques. The proposed technique decomposes video into meaningful hierarchical structure and provides video browsing or retrieval based on scene.

• Journal of Broadcast Engineering
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• v.15 no.4
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• pp.461-473
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• 2010

Since eco friendly and power saving products recently got into the limelight for the protection of environment, LED light technology has caught much of attention as the next generation broadcasting lighting. The newly introduced light source has such advantages as higher efficiency, longer life and its slim and compact forms leading to conveniency in installations. When combined with digital light control it gives more dynamic and various features to lighting. In this paper, used CIE standard for measuring light sources by their purposes and forms to make a comparative analysis of spectral distribution and color rendition of LED light source to those of existing lighting systems. By means of the cast shadowing and color reproduction tests I also tried to figure out the effects of LED lighting design on TV visuals where higher quality is crucial with the audience's increasing demands for quality image.

• Journal of Broadcast Engineering
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• v.19 no.1
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• pp.96-108
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• 2014

In case of contrast of the image enhancement by using the conventional histogram equalization, over-enhancement, false contouring and distortion such as the details disappearance of the image occurs due to the excessive brightness change. Especially, these distortion appears when the brightness distribution is concentrated in a particular brightness level. In order to solve these problems, improved histogram equalization methods to transform the input histogram by clipping using threshold have been proposed, but contrast enhancement effect is reduced because it does not consider the characteristics of the input image's histogram to apply the same threshold for the entire histogram, and unnatural image is obtained because it does not retain the characteristics of the image. In this paper, to solve the problems of existing methods, we propose new equalization method that suppress excessive brightness changes by applying to the differential compression according to the histogram frequency, and maintain the characteristics of the input image. In addition, we propose a more effectively method to improve contrast by controlling the strength of the compression ratio depending on the characteristics of the input image.

• Journal of Broadcast Engineering
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• v.18 no.5
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• pp.680-690
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• 2013

In this paper, we propose a real-time temporal synchronization and compensation algorithm in stereoscopic video. Many temporal asynchronies are caused in the video editing stage and due to different transmission delays. These temporal asynchronies can degrade the perceived 3D quality. The goal of temporal alignment is to detect and to measure the temporal asynchrony and recover synchronization of the two video streams. In order to recover synchronization of the two video streams, we developed a method to detect asynchronies between the left and the right video streams based on a novel spatiogram information, which is a richer representation, capturing not only the values of the pixels but their spatial relationships as well. The proposed novel spatiogram additionally includes the changes of the spatial color distribution. Furthermore, we propose a block-based method for detection of the pair frame instead of one frame-based method. Various 3D experiments demonstrate the effectiveness of the proposed method.

• Journal of Internet Computing and Services
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• v.14 no.3
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• pp.1-13
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• 2013

The recent emergence of diverse platform-based media devices such as smart phones and iPads has aroused interest of consumers all across the world. This interest has led to digitalization of paper books and a steep growth in the digital publishing industry at home and abroad. However, advent of various devices and content has caused the issue of compatibility and produced needs and demand for standardization to exchange and share content related to digital publication. Through collection of opinions of 16 stakeholders from the industrial, academic, research, and public sectors, this study aims to examine predictable future changes about content and its distribution, devices, standardization, technical protective measures, and obstacles in future digital publishing and eventually to draw out areas and elements for future standards development.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.8
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• pp.4072-4089
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• 2018

This paper introduces a scheme for optimizing the material properties of mass-spring systems of different resolutions to provide coherent behavior for reduced level-of-detail in MSS(Mass-Spring System) meshes. The global optimal material coefficients are derived to match the behavior of provided reference mesh. The proposed method also gives us insight into levels of reduction that we can achieve in the systematic behavioral coherency among the different resolution of MSS meshes. We obtain visually acceptable coherent behaviors for cloth models based on our proposed error metric and identify that this method can significantly reduce the resolution levels of simulated objects. In addition, we have confirmed coherent behaviors with different resolutions through various experimental validation tests. We analyzed spring force estimations through triangular Barycentric coordinates based from the reference MSS that uses a Gaussian kernel based distribution. Experimental results show that the displacement difference ratio of the node positions is less than 10% even if the number of nodes of $MSS^{sim}$ decreases by more than 50% compared with $MSS^{ref}$. Therefore, we believe that it can be applied to various fields that are requiring the real-time simulation technology such as VR, AR, surgical simulation, mobile game, and numerous other application domains.

• Journal of Microbiology and Biotechnology
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• v.2 no.2
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• pp.85-91
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• 1992

The intestinal microflora of humans is an extraordinarily complex mixture of microorganisms, the majority of which are anaerobic microorganisms. The distribution of amylolytic microorganisms in the human large intestinal tract was investigated in various individuals of differing ages using anaerobic culture techniques. A large percentage of the amylolytic microorganisms present belonged to the Genus Bifidobacteria. The number of Bifidobacteria increased significantly at two years of age. Adults and children above 2 years old carried about $0.8{\times}10^9-2.0{\times}10^{10}$ colony forming units (CFU/gram) of amylolytic Bifidobacteria. Among these amylolytic Bifidobacteria, Int-57 was chosen for further studies. Between 65% and 85% of the amylase produced was secreted and the remaining amylase was bound to the cell wall facing the outside. Amylase production could be induced by starch in a stable form. When cells were grown on maltose or glucose, amylase production was much lower than on starch and amylase activity disappeared after 24 hours growth on these media. Partially purified enzymes showed optimum activity at a temperature of $50^{\circ}C$ and at an optimum pH of 5.5, respectively. Heat treatment at $70^{\circ}C$ for 30 minutes almost completely inactivated amylase. The hydrolysis products of starch were mainly maltose and maltotriose. Soluble starch, amylose, amylopectin, and $\gamma$-cyclodextrin($\gamma$-CD) were easily hydrolyzed. The rate of hydrolysis of $\alpha$-CD and $\beta$-CD was slower than that of $\gamma$-CD. Carboxymethyl cellulose, $\beta$-1, 3-glucan and inulin were not hydrolyzed.

• Convergence Security Journal
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• v.17 no.1
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• pp.63-68
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• 2017

The Jasmine Revolution started from Tunisia in January 2011 has brought many changes into countries in North Africa and Middle East. We need to study the causes of the revolution. First, the kings and dictators in those countries oppressed the opposition parties and the media aiming for long-term seizure of power. The power concentrated on specific people produced illegalities and corruption. Secondly, most of the national income of those countries belonged to kings and dictators producing problems during the distribution of the income. Especially, with the decrease of oil price in 1990s and the increase of the price of daily necessities in 2000s people lost their credits on their governments. Lastly, the number of people in those countries using the Internet has increased by 4,863% from 2000 to 2010. The expansion of social network services such as Facebook and Twitter was one of factors that made the information control by those countries difficult. We should think about the possibility of sudden change in North Korea. It is necessary to compare and analyze the political, economic and social characteristics between those countries and North Korea. It shouldn't be just a simple comparison or analysis. It should provide basic data for objective and quantified index development in relation to sudden change in North Korea.

• Geophysics and Geophysical Exploration
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• v.7 no.1
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• pp.45-50
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• 2004

This paper describes a method of detecting formation boundaries, and permeable fractures, from frequency-domain Stoneley wave logs. Field data sets were collected between the depths of 330 and 360 m in well EE-4 in the Higashi-Hachimantai geothermal field, using a monopole acoustic logging tool with a source central frequency of 15 kHz. Stoneley wave amplitude spectra were calculated by performing a fast Fourier transform on the waveforms, and the spectra were then collected into a frequency-depth distribution of Stoneley wave amplitudes. The frequency-domain Stoneley wave log shows four main characteristic peaks at frequencies 6.5, 8.8, 12, and 13.3 kHz. The magnitudes of the Stoneley wave at these four frequencies are affected by formation properties. The Stoneley wave at higher frequencies (12 and 13.3 kHz) has higher amplitudes in hard formations than in soft formations, while the wave at lower frequencies (6.5 and 8.8 kHz) has higher amplitudes in soft formations than in hard formations. The correlation of the frequency-domain Stoneley wave log with the logs of lithology, degree of welding, and P-wave velocity is excellent, with all of them showing similar discontinuities at the depths of formation boundaries. It is obvious from these facts that the frequency-domain Stoneley wave log provides useful clues for detecting formation boundaries. The frequency-domain Stoneley wave logs are also applicable to the detection of a single permeable fracture. The procedure uses the Stoneley wave spectral amplitude logs at the four frequencies, and weighting functions. The optimally weighted sum of the four Stoneley wave spectral amplitudes becomes almost constant at all depths, except at the depth of a permeable fracture. The assumptions that underlie this procedure are that the energy of the Stoneley wave is conserved in continuous media, but that attenuation of the Stoneley wave may occur at a permeable fracture. This attenuation may take place at anyone of the four characteristic Stoneley wave frequencies. We think our multispectral approach is the only reliable method for the detection of permeable fractures.