• Korean Journal of Soil Science and Fertilizer
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• 제46권4호
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• pp.276-280
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• 2013

D. kaki and D. lotus are used as rootstocks for astringent persimmons in Korea but characteristics of their seedlings have not been determined. In this experiment, their seeds were sown in 3-L pots on April 18 and the seedlings were grown until October 24. Growth and nutrient absorption were compared at the end of the season after destructively harvesting the seedlings. Seedling growth of D. lotus was much faster than that of D. kaki in terms of total stem length, stem diameter, and number of leaves. However, chlorophyll value and specific leaf weight were higher in D. kaki than in D. lotus. Dry weight of D. lotus was 3.6- and 3.7-fold higher than that of D. kaki in above-ground parts and the root, respectively. D. kaki seedlings were characterized by higher concentrations of N, P, K, Ca, and Mg in the leaves, stem, or the root. However, total contents of the elements were 1.8- to 3.7-fold higher in a D. lotus seedling due to its greater dry weight. Since D. lotus seedlings absorbed more inorganic elements on a tree basis and grew more vigorously than D. kaki seedlings, the level of fertilization for astringent persimmons should be adjusted depending on rootstocks to maintain the trees at the optimum vigor.

• Proceedings of the KIEE Conference
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• 대한전기학회 1998년도 하계학술대회 논문집 D
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• pp.1481-1483
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• 1998

we have investigated the effect of aromatic compounds and tree inception and growth in low density polyethylene, for AC voltage and Impulse voltage. 2kinds of aromatic compounds are selected. Each additive (m-cresol, aniline) was mixed in low density polyethylene. For AC voltage, 10wt% $\sim$ 15wt% m-cresol can be shown to be the effective inhibitor to tree initiation. But, For Impulse voltage, 10wt% $\sim$ 15wt% aniline is effective inhibitor to tree initiation.

• Proceedings of the KIEE Conference
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• 대한전기학회 1997년도 하계학술대회 논문집 C
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• pp.1507-1509
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• 1997

Property of insulation of electric machine is severely affected by process of electrical tree growing. Partial discharges(PD) have been used to determine degradation of insulations. In this paper, PD quantities detected and analyzed are PD magnitudes, repetition rates, phase angle distribution of PD pulses, and wavelet transformation. The wavelet transformation is an extended method of fourier transformation. The fourier transformation is a powerful tool for signal analysis, but it can't include informations for time. However the wavelet transformation analysis can include on the informations of time and frequencies at the same time. This paper discusses correlation between process of electrical tree growing and characteristics of PD in LDPE specimens.

• Journal of Life Science
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• 제26권11호
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• pp.1341-1344
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• 2016

Dendropanax morbifera is an endemic tree species of Korea, it is restricted to the southern parts of Korea. The internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA) for Dendropanax morbifera grown at Bogil-do, Korea was determined. We investigated the sequence-based phylogenetic relationships of plants related and clarified its taxonomical position. The determined sequences consisted of 689 residues. ITS1 was 222 bp long while ITS2 was 233 bp long. The 5.8S rDNA was 160 bp long. The ITS region sequences of the Dendropanax species included in this study were obtained from GenBank. Oreopanax polycephalus was used as the outgroup. A pairwise alignment was calculated using the Clustal X program. A phylogenetic tree was constructed by the neighbor-joining method using the Tree view program. Sequence similarities among species including D. morbifera Bogil-do isolate showed the range 92.6 to 99.7% in sequence-based phylogenetic analysis using total 615 base pairs of ITS1, 5.8S rDNA and ITS2. D. morbifera Bogil-do isolate exhibited the highest degree of relatedness to D. chevalieri, sharing 99.7% ITS region similarity. D. morbifera Bogil-do isolate also showed to D. trifidus, sharing 99.4% ITS region similarity.

• ETRI Journal
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• 제30권2호
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• pp.341-343
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• 2008

This letter presents an angular minimum spanning tree (AMST) algorithm for topology control in multi-hop wireless ad hoc networks. The AMST algorithm builds up an MST for every angular sector of a given degree around each node to determine optimal transmission power for connecting to its neighbors. We demonstrate that AMST preserves both local and network-wide connectivity. It also improves robustness to link failure and mitigates transmission power waste.

• Journal of The Korean Association of Information Education
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• 제1권1호
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• pp.49-59
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• 1997

In this thesis, To provide the base of effective data access methods, performance of some indexing techniques used gent-Tally are compared. They are classified as primary key and multikey. For primary key method, made a comparative analysis on Static index. Dynamic index and Hashing. For multikey indexing method K-d tree, K-d-B tree, Inverted file and Grid file of which characteristics are compared. In many applications, multikey indexings are more requested, but are not supplied enough. So, to satisfy users' request - more fast, more exact and to be applied according to the trend of being huge database systems, it is requested more study about multikey data access methods.

• Journal of Korean Society on Water Environment
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• 제33권6호
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• pp.689-695
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• 2017

This study was carried out to investigate the physicochemical and adsorptive characteristics of black carbon (BC) materials for cesium in case of severe nuclear accidents. The BC was prepared with a xylem of oak and pine trees incompletely combusted with different ramp rate and final temperature. Carbon (C), hydrogen (H) and oxygen (O) atomic ratios, BET, pore structure, and zeta potential were characterized for the produced BC. A low cesium concentration ($C_w{\approx}10^{-7}M$) was used for sorption batch experiments. The H/C and O/C ratios of BC decreased with the increase of final temperature, which indicates a carbonization of the wood materials regardless of ramp rate and tree species. However, SEM images showed different pore structures depending on tree species such as steric and plate-like for oak-BC and pine-BC, respectively. The greatest sorption distribution coefficients of $K_{d,Cs}{\approx}1,200{\sim}1,800L\;kg^{-1}$ were observed for the oak-BC produced at $400^{\circ}C$, while comparatively low $K_{d,Cs}$ < $100L\;kg^{-1}$ for pine-BC. In addition, the sorption capabilities of BC declined with the increase of combustion temperature up to $600^{\circ}C$, because high temperature destroyed surface functionalities with the rise of ash components in the BC. Therefore, the sorption processes of BC for radioactive cesium are predominantly controlled by final production temperature of BC as well as raw materials (e.g., tree species).

• The KIPS Transactions:PartD
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• 제8D권2호
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• pp.145-153
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• 2001

The Pyramid-Technique is based on mapping n-dimensional space data into one-dimensional data and expressing it as B-tree ; and by solving the problem of search time complexity the pyramid technique also prevents the effect \"phenomenon of dimensional curse\" which is caused by treatment of hypercube range query in n-dimensional data space. The Spherical Pyramid-Technique applies the pyramid method’s space division strategy, uses spherical range query and improves the search performance to make it suitable for similarity search. However, depending on the size of data and change in dimensions, the two above technique demonstrate significantly inferior search performance for data sizes greater than one million and dimensions greater than sixteen. In this paper, we propose a new index-structured PdR-Tree to improve the search performance for high dimensional data such as multimedia data. Test results using simulation data as well as real data demonstrate that PdR-Tree surpasses both the Pyramid-Technique and Spherical Pyramid-Technique in terms of search performance.

• Journal of Environmental Science International
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• 제12권8호
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• pp.853-860
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• 2003

Plants sequester atmospheric CO$_2$, a major agent of climate change, during the growing periods and mitigate its rising accumulation in the atmosphere. Pinus densiflora and Quercus mongolica are the native tree species dominant in the temperate forests of Korea. This study quantified the annual CO$_2$ uptake by the two species at forest sites in Chuncheon in the middle of the country. The quantification was based on seasonal measurements of CO$_2$ exchange rates under natural conditions by an infrared gas analyzer over the growing season (1999). The monthly CO$_2$ uptake per unit leaf area ranged from 1.6-6.7 mg/d㎡/h for P. densiflora and from 3.7-8.9 mg/d㎡/h for Q. mongolica, with a maximum in mid-summer. An equation for each species was generated to estimate easily the annual CO$_2$ uptake by total leaf area per tree, which subtracted the CO$_2$ release (i.e. respiration) by leaves and woody organs from the gross CO$_2$ uptake (diurnal uptake and release by leaves). Annual CO$_2$ release by leaves and woody organs accounted for 58-73％ of the gross CO$_2$ uptake across tree specimens. Annual CO$_2$ uptake per tree increased with increasing dbh (stem diameter at breast height) for the study diameter range, and was greater for Q. mongolica than for P. densiflora in the same dbh sizes. This was mainly associated with a greater total leaf area in the former. For example, the annual CO$_2$ uptake by one tree with dbh of 25 cm was 35.6 kg/yr for P. densiflora and 47.9 kg/yr for Q. mongolica. The results from this study can be applied to evaluate an atmospheric CO$_2$ reduction of woody plants by forest type and age class.

• Proceedings of the KIEE Conference
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.178-182
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• 2002

For action selection as well as teaming, simple associations between stimulus and response have been employed in most of literatures. But, for successful task accomplishment, it is required that artificial life system can team and express behavioral sequences. In this paper, we propose a novel action-selection-mechanism to deal with behavioral sequences. For this, we define behavioral motivation as a primitive node for action selection, and then hierarchically construct a tree with behavioral motivations. The vertical path of the tree represents behavioral sequences. Here, such a tree for our proposed ASM can be newly generated and/or updated, whenever a new behavioral sequence is learned. To show the validity of our proposed ASM, three 2-D grid world simulations will be illustrated.