• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.6
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• pp.2492-2512
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• 2018

Multicast communication can effectively reduce network resources consumption in contrast with unicast. With the advent of SDN, current researches on multicast traffic are mainly conducted in the SDN scenario, thus to mitigate the problems of IP multicast such as the unavoidable difficulty in traffic engineering and high security risk. However, migration to SDN cannot be achieved in one step, hybrid SDN emerges as a transitional networking form for ISP network. In hybrid SDN, for acquiring similar TE and security performance as in SDN multicast, we redirect every multicast traffic to an appropriate SDN node before reaching the destinations of the multicast group, thus to build up a core-based multicast tree substantially which is first introduced in CBT. Based on the core SDN node, it is possible to realize dynamic control over the routing paths to benefit traffic engineering (TE), while multicast traffic manageability can also be obtained, e.g., access control and middlebox-supported network services. On top of that, multiple core-based multicast trees are constructed for each multicast group by fully taking advantage of the routing flexibility of SDN nodes, in order to further enhance the TE performance. The multicast routing and splitting (MRS) algorithm is proposed whereby we jointly and efficiently determine an appropriate core SDN node for each group, as well as optimizing the traffic splitting fractions for the corresponding multiple core-based trees to minimize the maximum link utilization. We conduct simulations with different SDN deployment rate in real network topologies. The results indicate that, when 40% of the SDN switches are deployed in HSDN as well as calculating 2 trees for each group, HSDN multicast adopting MRS algorithm can obtain a comparable TE performance to SDN multicast.

• Journal of Plant Biology
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• v.15 no.4
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• pp.1-12
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• 1972

To study on the annual height growth of Pinus densiflora within natural pine stands in central Korea, twenty two pure closed Pinus densiflora stands were selected subjectively in the west-central region of Korea. In each stand twenty trees were chosen randomly. For each tree, abotu ten to fifteen measurements of internodal lengths were made from leader top to trunk base. A total of one hundred thirty four soil samples was collected. Each soil sample was bulked with three subsamples. The ranges of the growth measurements per stand, per tree and per observation were 14.9-35.4cm, 9.0cm-54.4cm and 2.4cm-69.0cm respectively. The total mean value was 23.5cm. The Student-Newman-Keul's tests for the multiple comparison among the mean values of the height growth per stand were very highly significant. The resutls of the analysis of variance of the height growth data for the selected fifteen stands among the twenty two stands indicate that sampling efficiency might be increased to 744% if measurement of the growth were made on fifteen trees per stand from twenty stands instead of twenty trees per stand from fifteen stands. The annual height growths of Pinus densiflora and Pinus koraiensis for the period from 1960 to 1968 were 21.74$\pm$5.29cm (10) and 20.56$\pm$5.59cm (10) respectively. The total means of easily-soluble phosphorus, total nitrogen, loss on ignition and pH for the soil samples were 2.8 ppm, 0.09%, 5.4% and 4.7 respectively. The ranges of those amounts were 18.7-1.7ppm, 0.17-0.05%, 11.6%-3.1%, 3.9-5.1 respectively. The relationship of the annual height growth of P. densiflora to soil was studied in terms of standard partial multiple regression. Among soil properties such as non-capillary pore space, capillary pore space, maximum field capacity, loss on ignition, soil reaction, total nitrogen and easily-soluble phosphoros investigated, the easily soluble phosphorus in one analysis and loss on ignition and soil reaction in the other analysis seem to have significant positive influence on the annual height growth.

• Journal of Forest and Environmental Science
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• v.39 no.2
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• pp.81-95
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• 2023

Due to the multiple ecosystem benefits that iconic large, old growth trees provide, forest managers are applying thinning treatments around these legacy trees to improve their vigor and reduce mortality, especially in the face of climate change and other forest health threats. One objectives of this study was to analyze sub-hourly stem fluctuations of legacy ponderosa (Pinus ponderosa Dougl. Ex P. & C. Laws) and sugar pines (Pinus lambertiana Dougl.) in the mixed-conifer forests of the Sierra Nevada in multiple different radius thinning treatments to assess the short-term effects of these treatments. Thinning treatments applied were: R30C0 (9.1 m radius), R30C2 (9.1 m radius leaving 2 competitors), and RD1.2 (radius equaling DBH multiplied by 1 ft/in multiplied by 1.25). The other objective was to assess climatic drivers of hourly stem fluctuations. Using the dendrometeR package, we gathered daily statistics (i.e. daily amplitude) of the stem fluctuations, as well as stem cycle statistics such as duration and magnitude of contraction, expansion, and stem radial increment. We then performed correlation analyses to assess the climatic drivers of stem fluctuations and to determine which radial thinning treatment was most effective at improving growth. We found an important role that mean solar radiation, air temperature, and relative humidity play in stem variations of both species. One of the main findings from a management perspective was that the RD1.2 treatment group allowed both species to contract less on warmer and higher solar radiation days. Furthermore, sugar pine put on more stem radial increment on higher solar radiation days. These findings suggest that the extended radius RD1.2 thinning treatment may be the most effective at releasing legacy sugar and ponderosa pine trees compared to the other forest management treatments applied.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.05a
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• pp.243-246
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• 2003

Data mining is a process of discovering useful patterns for decision making from an amount of data. It has recently received much attention in a wide range of business and engineering fields Classifying a group into subgroups is one of the most important subjects in data mining Tree-based methods, known as decision trees, provide an efficient way to finding classification models. The primary concern in tree learning is to minimize a node impurity, which is evaluated using a target variable in the data set. However, there are situations where multiple target variables should be taken into account, for example, such as manufacturing process monitoring, marketing science, and clinical and health analysis. The purpose of this article is to present several methods for measuring the node impurity, which are applicable to data sets with multiple target variables. For illustrations, numerical examples are given with discussion.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.4
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• pp.357-364
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• 1999

This study measures the influence of grass cover on water use and shoot growth of apple trees growing under different soil water regimes in temperate climate conditions and evaluates monthly crop coefficients of such conditions during four months of the growing season in 1995. To do so, double pot lysimeter experiments of 3-year-old Fuji' apple (Males domestica Borkh.) trees under a transparent rain shield were designed and installed. Trees were triplicate under three soil water regimes: (A) drip-irrigation at -50 kPa of soil matric potential (IR50). (B) drip-irrigation at -80 kPa of soil matric potential (IR80), and (C) constant shallow water table at 0.45 m below the soil surface (WT45). In each treatment, two soil surface conditions were tested: the soil surface bare, and covered with turf grasses. Mean monthly water use increased with increasing soil matric potential for drip irrigation and was greatest in the WT45 treatment. Monthly crop coefficients increased linearly in time for drip-irrigated apple trees ($r^2$ values of $0.953^{***}$ for turf grass-covered system and of $0.862^{***}$ for bare surface system), while those obtained in the WT45 treatment fluctuated, Duncan's multiple range tests for shoot growth showed that grass-covered IR50 was most favorable to apple trees. while bare surface waterlogged situation was most adverse at least in part due to a lack of oxygen in the root zone. Mid-season leaf Kjeldahl-N was higher in drip-irrigated apple trees than in WT45 trees, while soil Kjeldahl-N was not different irrespective of treatments.

• Bulletin of the Korean Mathematical Society
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• v.56 no.1
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• pp.31-44
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• 2019

A graph theoretical model called Roman domination in graphs originates from the historical background that any undefended place (with no legions) of the Roman Empire must be protected by a stronger neighbor place (having two legions). It is applicable to military and commercial decision-making problems. A Roman dominating function for a graph G = (V, E) is a function $f:V{\rightarrow}\{0,1,2\}$ such that every vertex v with f(v)=0 has at least a neighbor w in G for which f(w)=2. The Roman domination number of a graph is the minimum weight ${\sum}_{v{\in}V}\;f(v)$ of a Roman dominating function. In order to deal a problem of a Roman domination-type defensive strategy under multiple simultaneous attacks, ${\acute{A}}lvarez$-Ruiz et al. [1] initiated the study of a new parameter related to Roman dominating function, which is called strong Roman domination. ${\acute{A}}lvarez$-Ruiz et al. posed the following problem: Characterize the graphs G with equal strong Roman domination number and Roman domination number. In this paper, we construct a family of trees. We prove that for a tree, its strong Roman dominance number and Roman dominance number are equal if and only if the tree belongs to this family of trees.

• The Plant Pathology Journal
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• v.37 no.6
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• pp.543-554
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• 2021

To preventively control fire blight in apple trees and determine policies regarding field monitoring, the Maryblyt ver. 7.1 model (MARYBLYT) was evaluated in the cities of Chungju, Jecheon, and Eumseong in Korea from 2015 to 2020. The number of blossom infection alerts was the highest in 2020 and the lowest in 2017 and 2018. And the common feature of MARYBLYT blossom infection risks during the flowering period was that the time of BIR-High or BIR-Infection alerts was the same regardless of location. The flowering periods of the trees required to operate the model varied according to the year and geographic location. The model predicts the risk of "Infection" during the flowering periods, and recommends the appropriate times to control blossom infection. In 2020, when flower blight was severe, the difference between the expected date of blossom blight symptoms presented by MARYBLYT and the date of actual symptom detection was only 1-3 days, implying that MARYBLYT is highly accurate. As the model was originally developed based on data obtained from the eastern region of the United States, which has a climate similar to that of Korea, this model can be used in Korea. To improve field utilization, however, the entire flowering period of multiple apple varieties needs to be considered when the model is applied. MARYBLYT is believed to be a useful tool for determining when to control and monitor apple cultivation areas that suffer from serious fire blight problems.

• Journal of the military operations research society of Korea
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• v.28 no.2
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• pp.34-55
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• 2002

This paper deals with the multiple attribute decision making problem when a decision maker incompletely articulates his/her preferences about the attribute weight and alternative value. Furthermore, we consider the attribute tree which is structured hierarchically. Techniques for establishing dominance with linear partial information are proposed in a hierarchically structured attribute tree. The linear additive value function under certainty is used in the model. The incompletely specified information constructs a feasible region of linear constraints and therefore the pairwise dominance relationship between alternatives leads to intractable non-linear programming. Hence, we propose solution techniques to handle this difficulty. Also, to handle the tree structure, we break down the attribute tree into sub-trees. Due to there cursive structure of the solution technique, the optimization results from sub-trees can be utilized in computing the value interval on the topmost attribute. The value intervals computed by the proposed solution techniques can be used to establishing the pairwise dominance relation between alternatives. In this paper, pairwise dominance relation will be represented as strict dominance and weak dominance, which ware already defined in earlier researches.

• Journal of Korean Society of Forest Science
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• v.105 no.4
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• pp.422-428
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• 2016

Ginkgo (Ginkgo biloba L.) is one of the most appropriate roadside trees because of a good transplantation nature and ability to grow well in urban environment. Ginkgo is a dioecious species. Sex discrimination of ginkgo is possible through comparing morphological characters of reproductive organs. However, it needs more than about twenty years for reproductive organs to appear after sexual maturity. Until now, ginkgo trees for roadside plantation have been planted without discriminating the sex because ginkgo trees have been usually planted before sexual maturity. Ginkgo nuts from the female ginkgo trees planted along the roadside emit a foul odor, and make much pollution on the streets. Thus in this study a novel SCAR marker (SCAR-GBM) for the early sex discrimination was developed. Primers were developed on the basis of the sequence of male-specific RAPD variants reported previously. False-negative problem of SCAR marker, probably caused by dominant nature, was resolved by using multiplex PCR using primers of both the SCAR-GBM and a universal primer set of atp1 region in mitochondria DNA, which resulted in improved discrimination efficiency. The results showed that DNA bands of 1,039 bp were commonly amplified by the atp1 primer set in male and female trees, and SCAR-GBM markers of 675 bp were specifically amplified only in male trees. Reproducible and specific discrimination of the multiplex PCR was finally confirmed by applying multiple male and female individuals.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.2
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• pp.77-94
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• 2020

Gugok poems were an important material for studying the Gugok landscape garden(九曲園林). the landscape feature(景物)that emerges from poetry is an important material that expresses the sense of placefulness and garden consciousness(園林意識). However, many studies are passive about plant materials that can explore the perception of nature or the aesthetic embodiment process. Therefore, this study seeks to discover various symbolic meanings and reveal the context of plants that have appeared in Gugok poems in order to expand the research material of the Gugok culture. To carry out the purpose of the study, I collected a total of 25 related poems from 18 Gugoks and found a total of 20 species of trees. I used 'R-program' to derive the meaning of trees and examined the meaning of trees by intertextuality. According to the study, the 20 species of trees contained symbolic meanings of world of Taoist hermit, pursuit of study, constancy, true pleasure, dignity, honest poverty, reign of peace, nostalgia. Many species focused on the symbolism of the 'world of Taoist hermit' and then on the 'dignity' was the most frequent. A number of species, except for the peach, zelkova and oak, had multiple meanings. Among them, pine trees and lotus had a wide range of symbolic meanings and different meanings depending on the characteristics of the surrounding landscape. While the Gugok culture generally targets natural scenery, Yongsan, Toegye, Deoksan, and Jusan showed the characteristics of strengthening or reproducing symbolic meanings through artificial plating and gardening. In order to overcome the limitations of the peach tree, which symbolizes 'Mureungdowon(武陵桃園)', Gugok poems used maple trees and reeds as alternative species. In accordance with the above context, the trees appearing in the Gugok poems expressed their symbolic meaning differently according to the landscape features, acts and purposes of the Gugoks, rather than sticking to the traditional meaning.