• Journal of KIISE:Computer Systems and Theory
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• v.29 no.3
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• pp.161-168
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• 2002

A secret sharing scheme is a cryptographic protocol to share a secret among a set of participants P in the way that only qualified subsets of P can reconstruct the secret whereas any other subset of P, non-qualified to know the secret, cannot determine anything about the secret. In this paper, we propose a new secret sharing scheme in hierarchical groups, whose hierarchy can be represented as a tree structure. In the tree structure, participants of higher levels have priorities to reconstruct the secret over participants of lower levels. In the absence of the participant of a higher level, it is possible for this participant to delegate the ability to reconstruct the secret to the child nodes of the next lower level through the transfer of his delegation ticket. This scheme has a dynamic access structure through the recursive delegation process from the root to lower levels where participants aren't absent.

• Journal of the Korean Ceramic Society
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• v.43 no.7 s.290
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• pp.393-401
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• 2006

The development of Korean glaze originated from the development of ash glazes. Ash not only has strong solubility but also can shows the glaze a variety of different colors according to what the glaze has in it as the main component. In addition, it gives a feeling of lucidness and softness. For these reasons, there are a lot of needs for ash and many potters want to take advantage of ashes as glaze. But natural ashes have not been widely used as glaze primarily because it is relatively hard to find or manufacture. Considering the difficulty of finding or manufacturing natural ashes, this study aims to formulate synthetic ash which not only is available to the potters in general but also has the sam ε characteristics as the natural ashes. To achieve this aim, this study examines the characteristics of the pine tree ash, the main component of the glaze of celadon porcelains, and the red pepper stem ash, the main component of the brown glaze, both of which have been used by the Korean traditional potters. In this study, the alkaline component of the glaze. A important ingredient when the ashes are synthesized, was supplied by mixing of $Na_2CO_3$, Chungju limestone and rice straw ash. Furthermore, the synthetic ash, when it shows no change of pH in its composition rate of 6:2:2, was found to be usable as the most stable material. In conclusion, the formula which frits some raw $materials-Na_2CO_3$, Chungju limestone and rice straw ash-can duplicate the synthetic ash which is simila to the natural ash.

• Journal of Korea Spatial Information System Society
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• v.6 no.2 s.12
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• pp.3-13
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• 2004

The TPR-tree exploits bounding rectangles based on the function of time in order to index moving objects. As time passes on, each edge of a BR expands with the fastest velocity vector. Since the expansion of the BR results in a serious overlaps between neighboring nodes, the performance of range query is getting worse. In this paper, we propose schemes to reorganize bounding rectangles of nodes. When inserting a moving object, we exploit a forced merging scheme to merge two overlapped nodes and re-split it. When deleting a moving object, we used forced reinsertion schemes to reinsert other objects of a node into a tree. The forced reinsertion schemes are classified into a deleted node reinsertion scheme and an overlapped nodes reinsertion scheme. The overlapped nodes reinsertion scheme outperforms the forced merging scheme and the deleted node reinsertion scheme in all experiments.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.11
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• pp.7-13
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• 2010

For swiftness and economic feasibility of parcel delivery, optimal location of mail exchanging centers considering not only section delivery distance but also some weights like the number of delivery vehicles are necessary. In this paper, a mechanism with section delivery distance and vehicle number for locating of mail distribution centers which connect some mail centers of major cities in Republic Korea by applying GOSST theory is proposed. This mechanism for locating mail exchange centers can make the total delivery distance of postal matters less than not only present method which assigns Daejun as mail exchange center, but also Steiner tree method which does not consider weights like number of delivery vehicles. The mechanism is good for protecting the environment as well as rapid and economic delivery. In experiment, the proposed mechanism could curtail total delivery distance by 2.52 percentages compared with Steiner tree method and by 6.66 percentages compared with present method. The mechanism may be used in electric power transmission routing, distribution line topology design, power relay station locating where various voltages and other weights should be considered.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.3B
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• pp.255-263
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• 2009

In this paper, we propose an adaptive beacon scheduling algorithm to control a reception period of actual data according to variation of amount of traffic in IEEE 802.15.4 LR-WPAN(Low Rate-Wireless Personal Area Network) with the cluster-tree topology. If a beacon interval is shortened, the amount of the traffic a node receives can be increased while consumption of the energy can be also increased. In this sense, we can achieve optimal on orgy consumption by controlling the beacon interval when the amount of data to be received is being decreased. The result of simulation using NS-2 shows that the proposed algorithm improves performances in terms of packet loss rate and end-to-end delay compared with algorithm using a fixed beacon interval. For a design of cluster-tree based LR-WPAN managing delay-sensitive services, the proposed algorithm and the associated results can be applied usefully.

• The Transactions of the Korea Information Processing Society
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• v.1 no.1
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• pp.81-91
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• 1994

A DCT map and new cldebook design algorithm based on a two-dimension discrete cosine transform (2D-DCT) is presented for coder of image vector quantizer. We divide the image into smaller subblocks, then, using 2D DCT, separate it into blocks which are hard to code but it bears most of the visual information and easy to code but little visual information, and DCT map is made. According to this map, the significant features of training image are extracted by using the 2D DCT. A codebook is generated by partitioning the training set into a binary tree based on tree-structure. Each training vector at a nonterminal node of the binary tree is directed to one of the two descendants by comparing a single feature associated with that node to a threshold. Compared with the pairwise neighbor (PPN) and classified VQ(CVQ) algorithm, about 'Lenna' and 'Boat' image, the new algorithm results in a reduction in computation time and shows better picture quality with 0.45 dB and 0.33dB differences as to PNN, 0.05dB and 0.1dB differences as to CVQ respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.201-204
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• 2017

People live in their everyday life busy with studies, part-time jobs, and searching for an ideal job. In their busy routine, they try to find time for themselves and expose their emotions through diverse social network services(SNS). We made a service that we can plant a virtual tree in places we daily visit and go by. You can keep note on the virtual tree and look through the past records. It is a reality based mobile application service that can be used like a diary.In this project we chose the tree as the metaphor and tried to express time passing in a specific place. As our memory is a part of our daily life, we emphasized the meaning of space important.

• KIISE Transactions on Computing Practices
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• v.21 no.8
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• pp.572-577
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• 2015

Generally, the existing Artificial Intelligence (AI) systems were designed for specific purposes and their capabilities handle only specific problems. Alternatively, Artificial General Intelligence can solve new problems as well as those that are already known. Recently, General Video Game Playing the game AI version of General Artificial Intelligence, has garnered a large amount of interest among Game Artificial Intelligence communities. Although video games are the sole concern, the design of a single AI that is capable of playing various video games is not an easy process. In this paper, we propose a GreedyUCB1 algorithm and rollout method that were formulated using the knowledge from a game analysis for the Monte-Carlo Tree Search game AI. An AI that used our method was ranked fourth at the GVG-AI (General Video Game-Artificial Intelligence) competition of the IEEE international conference of CIG (Computational Intelligence in Games) 2014.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.3
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• pp.85-98
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• 2021

In this study, the characteristics of tree growth and soil environment were analyzed at 5 sites that had been planted on the back slope of dam for more than 15 years in Korea. First, as a result of investigating the growth of 15 trees planted on the back slope of the dam, the average height was 10.6m, diameter at roots was 27.3cm, and DBH was 22.9cm, showing good growth status of most of the trees. In particular, the growth levels of pine, hackberry, and oak were similar or better than those of general forests and artificial ground. As a result of excavating and investigating the roots of trees, horizontal roots grew well in the left and right directions of the back slope of the dam, and the growth of vertical roots was insufficient. Currently, the roots of trees do not directly affect dam safety, but they may continue to grow in the long term and interfere with dam management. Second, the physicochemical characteristics of the soil on the back slope of dam were generally above the intermediate level in terms of landscape design standards, and were similar to those of the domestic forest soil. Therefore, although it was judged to be suitable for plant growth, isolation of the site, soil acidification, and nutrient imbalance may affect tree growth and forest health in the long term. Through this study, it was possible to confirm the potential and applicability of planting area on the back slope of dam as an ecological base. Continuous monitoring is required for safety management and ecological value of dams in the future, and through this, it will be possible to secure the feasibility of planting trees on the slopes of new or existing dams and improving management.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.128-128
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• 2021

Most of the studies about stormwater low impact development technologies used generalized observations without fully understanding the mechanisms affecting the whole performance of the systems from catchment to the facility itself. At present, these LID technologies have been treated as black box due to fluctuating flow and environmental conditions affecting its operation and treatment performance. As such, the implications of microbial community to the overall performance of the tree-box filter were investigated in this study. Summer season was found to be the most suitable season for microorganism growth since more microorganism were found during this season. Least microorganism count was found in spring because of the plant growth during this season since plant penology influences the seasonal dynamics of soil microorganisms. Litterfall during fall season might have affected the microorganism count during winter since, during this season, the compositional variety of soil organic matter changes affecting growth of soil microbial communities. Microbial analyses of sediment samples collected in the system revealed that the most dominant microorganism phylum is Proteobacteria in all the seasons in both inlet and outlet comprising 37% to 47% of the total microorganism count. Proteobacteria was followed by Acidobacteria, Actinobacteria and Chloroflexi which comprises 6% to 20%, 9% to 20% and 2% to 27%, respectively of the total microorganism count for each season. These findings were useful in optimizing the design and performance of tree box filters considering physical, chemical and biological pollutant removal mechanisms.