• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.2
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• pp.33-39
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• 2015

Power supplying capacity of the distribution feeder should be maintained within thermal capacity of the wire. This paper presents the minimum spanning tree based load balancing technique to release multiple overloading of distribution feeders. In order to minimize number of involved backup feeders, Dijkstra and Prim algorithm are adopted to construct minimum spanning tree. Simulation testing result based on part of KEPCO's commercial distribution systems shows effectiveness of proposed scheme.

• Journal of Korean Society of Forest Science
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• v.95 no.5
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• pp.524-531
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• 2006

Neem tree (Azadirachta indica), native to the Indian sub-continent, has been known since the ancient time for its medicinal and insect repellent properties. In recent years, Neem has attracted global attention due to its potential as a source of natural drugs and also environment-friendly pesticides. In the households. The distribution and traditional practice on Neem can be important to the agriculturist, ethno-pharmaceutical developers and to the rural development practitioners in Bangladesh. An exploratory survey on the distribution and traditional practice on Neem tree in the rural homesteads of Chittagong coastal plain, Bangladesh, was conducted over a period of three months from September 2002 to November 2002. It was found that maximum, 64% households used seedling as planting material having 40% maximum sources Within the major tree species present in the homesteads, Neem accounted for 12% among the total individuals. It was found that the availability of Neem trees was found maximum, 31%, in the homesteads of medium sized households. Maximum, 42% individuals of Neem were found within the DBH of 10.1 to 20 cm; and 37% within the 3.1 to 6 m height classes. Neem trees were found to be used maximum, 88% for furniture. The findings of the study will be of immense importance for the rural development practitioners and ethno pharmacological developers in Bangladesh.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.1367-1369
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• 2013

Applying Application-Level Multicast technology (ALM) to Distributed Interactive Applications (DIAs) becomes more and more popular. Especially for DIAs embedded priority that the sender forwards data to receivers due to their respective priorities. The priority-based directed minimum spanning tree (PST) algorithm was designed for these DIAs. However, the PST has no efficient priority selection and filtering mechanism. The system will consume a tremendous amount of resource for reconstructing distribution tree and becomes unstable and unscalable. In this paper, First, We propose a novel priority-based application level multicast algorithm: Predict-and-Quantize for Priority with directed minimum Spanning Tree (PQPST), which can efficiently predict efficient priorities for the receivers and quantize the predicted priorities to build the multicast distribution tree. Second, we propose Priority Discrepancy Heuristic Mechanism (PDHM), which sets different thresholds of priority discrepancy within the priority discrepancy interval to control the distribution tree construction can efficiently decrease the repeated distribution tree construction, and we get the best heuristic priority discrepancy interval by PQPST. According to the simulation results, the PQPST and PDHM can efficiently improve the performance of the PST algorithm.

• Journal of Korean Society of Forest Science
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• v.108 no.2
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• pp.139-146
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• 2019

This study was conducted to determine the carbon (C) and nitrogen (N) distribution within tree components (i.e., stem, branches, leaves, and roots) of the Japanese larch (Larix kaempferi Carriere) plantation and natural oriental cork oak (Quercus variabilis Blume) stands. Fifteen Japanese larch and 15 oriental cork oak trees were destructively sampled to compare the C and N stocks in the components of the trees from three different regions-Hadong-gun, Hamyang-gun and Sancheong-gun-in Gyeongnam Province, South Korea. Species-specific allometric equations were developed to estimate the C and N contents in the tree components based on the diameter at breast height (DBH). There were differences in mean C and N concentrations between the Japanese larch and the oriental cork oak. The mean C concentrations of the tree componentswere significantly higher in Japanese larch than in oriental cork oak; whereas, the N concentration in the stems was significantly lower in Japanese larch than in oriental cork oak. The allometric equations developed for C and N content were significant (p < 0.05) with a coefficient of determination ($R^2$) of 0.76 to 0.99. The C and N stocks in the tree components do not appear to be affected by the species such as Japanese larch plantations and oriental cork oak stands. This study emphasizes the importance of C and N concentrations to estimate the C and N distribution according to tree components in different tree species.

• KIEE International Transactions on Power Engineering
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• v.5A no.2
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• pp.177-185
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• 2005

This paper proposes an expert system that can enhance the accuracy of real-time bus reconfiguration strategy by adopting the local minimum tree search method and that can minimize the spreading effect of the fault by considering the operating condition when a main transformer fault occurs in an automated substation. The local minimum tree search method is used to expand the best-first search method. This method has the advantage that it can improve the solution performance within the limits of the real-time condition. The inference strategy proposed expert system consists of two stages. The first stage determines the switching candidate set by searching possible switching candidates starting from the main transformer or busbar related to the event. The second stage determines the rational real-time bus reconfiguration strategy based on heuristic rules from the obtained switching candidate set. Also, this paper proposes generalized distribution substation modeling using graph theory, and a substation database based on the study results is designed.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.10
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• pp.565-572
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• 2004

This paper proposes an expert system which can enhance the accuracy of real-time bus reconfiguration strategy by adopting local minimum tree search method and minimize the spreading effect of the fault by considering totally the operating condition when a main transformer fault occurs in the automated substation. The local minimum tree search method to expand the best-first search method. This method has an advantage which can improve the performance of solution within the limits of the real-time condition. The inference strategy proposed expert system consists of two stages. The first stage determines the switching candidate set by searching possible switching candidates starting from the main transformer or busbar related to the event. And, second stage determines the rational real-time bus reconfiguration strategy based on heuristic rules for the obtained switching candidate set. Also, this paper studies the generalized distribution substation modelling using graph theory and a substation database is designed based on the study result. The inference engine of the expert system and the substation database is implemented in MFC function of Visual C++. Finally, the performance and effectiveness of the proposed expert system is verified by comparing the best-first search solution and local minimum tree search solution based on diversity event simulations for typical distribution substation.

• Korean journal of applied entomology
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• v.29 no.4
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• pp.238-243
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• 1990

These studies were conduced to investigate the effects of temperatures on development of each stage and distribution within tree and overwintering of mulberry scale, Pseudaulacaspis pentagona Tar. & Tozz. Growth ratio of each stage with different temperatures was not significant within range of optimum temperatures of growth. Developmental threshold and effective temperatures of each stage were $12.3^{\circ}C$ and 46.9 degree day in eggs, $10.8^{\circ}C$, and 183.8 degree day in first nymph, $9.8^{\circ}C$ and 188.2 degree day in second nymph, $10.3^{\circ}C$ and 383.0 degree day in gross nymphal stage, respectively. Longevity of female adults were 39.6 days in $18^{\circ}C$, 28.4 days in $22^{\circ}C$, 18.1 days in$26^{\circ}C$, and 15.7 days in$30^{\circ}C$. Average number of eggs in ovary and laid by individual female were 83.3 and 75.7, respectively. Optimum temperatures of growth were $22^{\circ}C$-$26^{\circ}C$ but all the eggs were not hatched at $35^{\circ}C$. Distribution of each stage within tree in summer was great at lower part of branch and overwintering adults was dominantly located in NE-SE followed by SE-SW, SW-NW and NW-NE. Percent mortality due to cold weather was 36.2.

• Journal of the Korean Wood Science and Technology
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• v.25 no.3
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• pp.37-42
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• 1997

This study was carried out to track the heated-air flows within the tree disk through measuring the distribution of wood temperatures during explosing the 7.5mm-thick Japanese cedar disk and to investigate the effects of the time for the first explosion cycle and the number of explosion cycles on the improvement of permeability of tree disk. If the tree disk are explosed when the temperatures of the shell and core of it are not equilibrium yet, all of the inflated airs in the shell after explosion don't flow out toward the autoclave and some of them flow into the core of which the air pressures are lower than those of the shell. It is very effective for the improvement of permeability of tree disk to make the first explosion cycle when the temperatures of the shell and the core equilibrate at the setting temperature of steam in the autoclave. The more tree disks were explosed under the same conditions of first explosion, the more their permeabilities were improved.

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.345-352
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• 1998

A Korean endemic and evergreen small tree ' Dendropanax morbifera $L_{EV}$.(Araliaceae)' is a component of evergreen forest and mainly idstributein sourthern region and islands in Korea. A local population of D. morbifera which is located between evergreen and deciduous forest within 50m x 50m quadrate was investigated to ascertain the change of population structure, emergence and growth dynamics of seedlings and saplings, and pattern of spatial distribution by the temproal and spatial expansion of population . The result of analysis of population structure by Importnace Value(IV), evergreen forest showed a high species diversity of evergreen tree species such as Cinnamomum japonicum, Machilus japonica, Neolitsea serica, Daphniphyllum macropodum, Ligustrum japonicum, and etc, in middle and under story than in upper story where Camelia japonica and Quercus acuta were dominant. And in conterminous deciduous fores, the major component of evergreen forest in this region, Camellia japonica, Quercus acuta, evergreen tree of Lauraceae and etc. were abundant in only under story. IV of D. morbifera differed from among three story. In comparative analysis of emergence and growth dynamics of D. morbifera seedlings and saplings between evergreen and deciduous forest, emergece and density of seedlings were significantly greater in evergreen than in deciduous forest, and growth of height and basal diameter of seedlings and saplings were slightly larger in evergreen than in deciduous forest. The spatial distribution patterns by Moristia's index mapping of indivuduals using a lattice method of XY axis within this population showed that seedlings(age up to 2 years) and saplings (age>2 years and height<1m) both evergreen and deciduous forest were more or less aggregated apart from mature trees, and thougth intermediate trees(height>1m and dbh<10cm) had a aggregated distribution pattern, mature trees(dbh>10cm were uniform. In conclusion , the expansion of D. morbfera population from evergreen to deciduous forest accompanied with a mumber of evergreen woody species, and also, emergence and recruitment, and growth of seedlings were greatly influenced moisture and canopy by around community structure.

• Korean journal of applied entomology
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• v.36 no.2
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• pp.150-155
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• 1997

Distribution of pine needle gall midge infestations was analyzed from data collected in young Japanese red pine stands during 1992, and 1995-1996 in Kangwon-do. No significant differences in percentages of infested needle pairs were found among trees and between terminal and lateral shoots within a tree. However, the mean percentages of infested needle pairs increased significantly from the lower crown to the upper. Percentages of infested needle pairs on sample units, consisting 1 terminal and 2 lateral shoots, in the midcrown were best predictors of whole-tree percentages than were other crown levels. Therefore, a sample unit consisting of 1 terminal shoot and 2 lateral shoots per branch were fixed from the midcrown level. Number of tree and sample unit combinations needed to estimate pine needle gall midge infestations with given two levels of precision were determined.