• Journal of Broadcast Engineering
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• v.9 no.3
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• pp.207-213
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• 2004

The layered depth image (LDI) is an efficient approach to represent three-dimensional objects with complex geometry for image-based rendering (IBR). LDI contains several attribute values together with multiple layers at each pixel location. In this paper, we propose an efficient preprocessing algorithm to compress depth information of LDI. Considering each depth value as a point in the two-dimensional space, we compute the minimum distance between a straight line passing through the previous two values and the current depth value. Finally, the minimum distance replaces the current attribute value. The proposed algorithm reduces the variance of the depth information , therefore, It Improves the transform and coding efficiency.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.533-536
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• 2008

It is on increasing trend to employ H-rolled beams as main flexural members of bridges and of temporary structures owing to their handiness for construction, maintenance, and management. But in the case of applying H-rolled beams to bridges, maximum length of bridge span is around 20m. Therefore, to develop simplified steel-concrete composite bridge having long span using H-rolled beam needs new cross girder system at internal supports, optimization of bridge system without cross beams between supports and steel-concrete composite bridge deck. This study performs mechanical analysis of cross girder system for H-rolled beam steel-concrete composite bridge with long span and verifies its usefulness.

• Journal of the Korea Computer Graphics Society
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• v.7 no.2
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• pp.29-35
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• 2001

In general, image-based virtual environment is represented by panoramic images created by image mosaic algorithm. The cylindrical panoramic image supports the fixed-viewpoint navigation due to the constraints of construction. Shum proposed concentric mosaics to allow users to navigate freely within a circular area[10]. It is constructed by a sequence of images which is acquired from a regularly rotating camera. Concentric mosaics technique, proposed by Shum, is considered as 3D plenoptic function which is defined three parameters : distance, height and angle. In this paper, we suggest an effective method for creating concentric mosaics, in which we first align a set of strip images on the cylinder plane and stitch the aligned strips to build a panoramic image. The proposed method has no constraints such as regular panning motion of camera. Furthermore, our proposed method minimizes the use of interpolation image to create a novel view images from the concentric mosaics. It allows the result image on a novel view to have better quality with respect to the number of input images.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.20 no.3
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• pp.91-96
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• 2014

TTI was applied to monitor the quality changes of fish displayed at a mock store. Chilled fishes were displayed with TTI on a styrofoam box filled with crushed ice. The ice was periodically refilled to maintain the fish freshness. The color of TTI and the qualities of mackerel and Alaska pollack were measured during displaying. VBN and Pseudomonas spp. were used as the quality factors of mackerel and Pollack, respectively. The spoilage time was regarded as when the factors reached their critical levels. The fishes were spoiled when the color of TTI reached an end-point. It was therefore found out that it is possible to predict the fish spoilage by observing the TTI color change.

• Journal of Broadcast Engineering
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• v.24 no.6
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• pp.1053-1063
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• 2019

Recently, tile-based streaming that transmits one 360 video in several tiles, is actively being studied in order to transmit these 360 video more efficiently. In this paper, for the transmission of high-definition 360 video corresponding to user's viewport in tile-based streaming scenarios, a system of assigning the quality of tiles at each tile by applying the saliency map generated by existing network models is proposed. As a result of usage of Motion-Constrained Tile Set (MCTS) technique to encode each tile independently, the user's viewport was rendered and tested based on Salient360! dataset, streaming 360 video based on the proposed system results in gain to 23% of the user's viewport compared to using the existing high-efficiency video coding (HEVC).

• KDI Journal of Economic Policy
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• v.14 no.1
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• pp.61-87
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• 1992

Reducing the level of greenhouse gas emissions is necessary to mitigate global warming. One of the most feasible methods to reduce emissions would be to conserve energy and substitute fossil fuels. Yet reducing emissions entails huge financial costs, so it is advisable to employ cost-effective economic instruments such as a carbon tax or tradeable emissions permits. Assuming that the proper economic tools will be used in the future, we calculated the optimal level of emissions reduction for Korea. We applied to our cost-benefit analysis Nordhaus' scenario regarding the economic damage from a $3^{\circ}C$ rise in global temperatures, which is the calculated result when the greenhouse gas level doubles. The result of our analysis based on the 1990 data indicates that the optimal level of emissions reduction ranges from 2% to 15 % of current emissions depending on the value of damage parameters. We also found that the amount of emissions must be reduced will increase if action is postponed, when the development of climate engineering technology or more efficient use of energy is expected. In addition, we discussed the advantages and disadvantages of the economic instruments available to implement emissions reduction. Tradeable permits and carbon tax are equivalent in their cost-effectiveness, but have different implications in practice.

• The Korean Journal of Financial Management
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• v.25 no.3
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• pp.79-109
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• 2008

According to asymmetric information hypothesis (for example, Ross (1977), Myers and Majluf (1984)), the impact of seasoned equity offering (SEO) announcement on the stock price depends mainly on the informational market efficiency. Despite of the importance of this fact, most of the previous SEO-related studies have done under the assumption of equal informational market efficiency among sample firms. This study intends to solve this problematic assumption and explores the real impact of SEO announcement on the stock prices. For this purpose, we divide 122 SEO firms into two subgroups; one with firms from KOSPI200 and the other including firms from the rest of KOSPI, assuming the former is more informationally efficient than the latter. Different from the US market-based study demonstrating short-and long-term negative price impacts of SEO announcement, most of the Korean market-based ones show price increases up until the announcement and decreases just after the announcement and in the long run. These previous studies attribute this difference to the different market system and regulation between them. Our results indicate that this discrepancy can be attributed to the different degree of market efficiency as well as the different market system and regulation.

• Journal of the Korean GEO-environmental Society
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• v.11 no.10
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• pp.41-48
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• 2010

In this study, grain size distribution of dredged soil and suspended solid distribution of supernatant in containment area were measured and compared with design prediction for suitability evaluation on prediction of suspended solid concentration of supernatant in conventional design of containment area. In addition to that, relationship were also analyzed between current velocity and suspended solid concentration of supernatant. Evaluation results show a relatively good agreement between field measurement and design prediction. On contrast, field measurement and design prediction show a quite different value each other in the early stage of dredging or at a point that current velocity increases. It is believed that this is due to that conventional design method of containment area does not account for ponding depth and current velocity which change sensitively with dredging period. Since current velocity and distribution of suspended solid concentration measured simultaneously show a similar trend, it is observed that there exists a close relationship between current velocity and distribution of suspended solid concentration. Therefore, a new design method for containment area, which can consider sedimentation of suspended solid that changes with interface height of dredged soil, ponding depth, current speed of supernatant, is necessary in order to predict the situation change of containment area more precisely.

• Korean journal of communication and information
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• v.55
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• pp.74-99
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• 2011

This article tries to find out some regulatory facts to improve and vitalize roles of social media such as facebook, twitter, etc in the election campaign. For this goal, a theoretical approach is based on the agnostic and open aspects of the regulation system of election. Case study and in-depth interview were used as research methods in this article. The results are as follows. First, some differences are in the election regulatory system regarding the roles of social media in UK, US, Japan and Korea. The election public sphere systems of these countries categorized to the types of legal factors to control political communications in election public sphere; free-speech oriented system(UK. US), limited free-speech oriented system(Korea), normative-oriented system(Japan). Second, most respondents answered they agreed with some improvement ideas to reflect needs of netizen and academic who suggest to minimize regulatory burdens on social media in the political communication during the election campaign.

• Journal of Navigation and Port Research
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• v.35 no.1
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• pp.77-82
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• 2011

The export of the containers consists of two steps, carrying them into the container yard and, then, out to the ship. For the safety of the ship, the heavier container should be loaded at the lower part of the ship. Because of this, the container rehandling happens during carrying out to the ship, and the number of the rehandling container is an important factor for the loading and unloading capability. There has been many studies for utilizing the idle times after loading the containers in the container yard. This study suggests the method of decreasing the number of container rehandling by preprocessing the container using the information about the weight of the container. This method is the preprocessing one which can decrease, during carrying into the container yard, the number of container rehandling which can happen during carrying out to the ship, and, according to the simulation test, it showed to be more effective than other method.