• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.4
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• pp.171-188
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• 2013

Landuse changes and cadastral information error categories in the four major river areas were analyzed for the use of policy data as cadastral re-arrangement of national and public lands would be required, using high-resolution air-photographs and cadastral maps before and after the river development. The study sites were the river areas of 40km around four dams of the Nakdong river where their landuses were changed most. As the results, national and public lands reached 79.9% of land parcels and 93.3% of land areas of the study sites similar with those of the four river areas, 84.3% of land parcels and 85.5% of land areas. The landuse classification of the study sites before the four river development was consisted most of 'river'(71.6%) and 'rice field'(12.3%), but after the development the 'river' was reduced to 42.7% and 'park area'(19.6%) including sport fields and 'mixed lots'(20.8%) were increased. Also, 86.7% of land parcels before the development could be reduced after the development if administrative districts and land ownerships were not considered. Cadastral information error categories can be found as cadastral polygon missing, polygon overlap, location and boundary non-coincidence, small polygon generation, and non-coincidence between cadastral boundary and river boundary. Landuse change monitoring method using air-photographs will be useful to analyze landuse state through fast information aquisition and to manage properties of national and public lands such as river areas.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.4
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• pp.348-354
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• 2015

Urethane waterproofing materials which currently being used most commonly in the Korean domestic market have high applicability and construct layers without forming any joints, but under the influence of low temperature and low humidity, as well as the thickness of the applied layer, the curing time of this material may become extended in construction sites. To resolve these issues, a proposed method of using water-hardening type of polyurethane waterproofing materials are being developed. However, there currently lacks any standards or evaluation methods on determining an optimal mixture ratio of water for the water-hardening polyurethane waterproofing materials. Therefore, workers and construction workers are relying on their hands-on-skills and experience to determine this ratio and are not able to obtain a consistent performance quality out of these materials. Therefore, for the establishment of a board applicability of the water-hardening polyurethane waterproofing methods in construction sites, this study objectively analyzes the changes in the performance of these materials depending on the changes of the water mixture ratio and attempts to procure the optimal ratio on the basis of forming a provisionary standard. The study prepares mixtures of varying ratio(no water added, 5, 10, 15, 20, 25, 30, 40 and 50) and conducts comparative analysis respective mixtures' performances and their changes in the physical properties in an objective manner and proposes a provisional optimal value that can serve as a data base that can be used as a reference for future studies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.6
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• pp.1283-1293
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• 2014

In ubiquitous environment, data are changing rapidly and new data is coming as times passes. And sometimes all of the past data will be lost if there is not sufficient space in memory. Therefore, there is a need to make rules and combine it with new data not to lose all the past data or to deal with large amounts of data. In making decision trees and extracting rules, the weight of each of rules is generally determined by the total number of the class at leaf. The computational problem of finding a minimum finite state acceptor compatible with given data is NP-hard. We assume that rules extracted are not correct and may have the loss of some information. Because of this precondition. this paper presents a new approach for refining rules. It controls their weight of rules of previous knowledge or data. In solving rule refinement, this paper tries to make a variety of rules with pruning method with majority and minority properties, control weight of each of rules and observe the change of performances. In this paper, the decision tree classifier with extended data expression having static weight is used for this proposed study. Experiments show that performances conducted with a new policy of refining rules may get better.

• Journal of Digital Convergence
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• v.12 no.10
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• pp.317-327
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• 2014

To improve the efficiency of wireless channel, IEEE 802.11ac uses the DL MU-MIMO MAC scheme through which an AP transmits multiple frames to different mobile nodes simultaneously. IEEE 802.11ac DL MU-MIMO MAC needs a new step, called as TXOP sharing, between legacy IEEE 802.11n DL SU-MIMO's two operations, the obtaining an EDCA TXOP and the transmitting multiple frames for EDCA TXOP. In the TXOP sharing operation, both wireless channel destinations and frames transmitted for its TXOP period should are determined. So this paper deals with the TXOP sharing for improving IEEE 802.11ac MAC performance. However, the EDCA priority based method mentioned by IEEE 802.11ac standard document not fair among the buffers and the frames of buffers, and occurs in high_loss rate and high_delay about specific buffers. In this paper, we propose a new scheme of the TXOP sharing with sequencing p-AC, s-AC in similar properties, and all S-AC. This method provides a differentiated service without damage of EDCA characteristics.

• Journal of Digital Convergence
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• v.13 no.5
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• pp.337-344
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• 2015

Medicinal plants containing wellness-fusion-complex compound are increasingly being pursued as suitable alternative sources of various biological properties. In this study, inhibitory effect of Quintinia acutifolia, which is a New Zealand plant, on P388 murine lymphocytic leukemia cells using MTT [3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl-tetrazolium bromide] assay. Based on $^1H-NMR$, $^{13}C-NMR$ spectral data and other spectral analysis, 2,3,2'',3''-tetrahydroochanaflavone (1) and 2'',3''-dihydroochana-flavone (3) inhibited the leukemia cells were purified from the plants. 2,3,2'',3''-tetrahydroochanaflavone (1) and 2'',3''-dihydroochana-flavone (3) are biflavonoids possessing two basic flavonoids and actively inhibited growth of P388 murine lymphocytic leukemia cells with a 50% inhibitory concentration ($IC_{50}$) of $8.2{\mu}g/mL$ and $3.1{\mu}g/mL$, respectively. Specially, 2'',3''-dihydroochana-flavone (3) possessed unconjugated flavonone system, which isn't consist of a pair with B ring of 2,3,2'',3''-tetrahydroochanaflavone (1). Therefore, the two compounds could be considered as a candidate for development of anticancer drugs and need to much studies in the future.

• Journal of Digital Convergence
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• v.15 no.7
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• pp.159-167
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• 2017

According to the statistics of the National Industrial Security Center under the National Intelligence Service, 209 national technologies have been leaked abroad in the past 5 years. Small and medium-sized enterprises and leakage by insiders accounted for 73% and 80% of them, respectively. This suggests that all the capabilities for preventing leakage of industrial technology should be focused on small and medium-sized enterprises and leakage by insiders. Related studies have been actively conducted on legal consideration of industrial technology leakage crimes, improvement of industrial security policies, and industrial security measures for preventing leakage of industrial technology, but adequate empirical studies have not been carried out on factors of leakage of industrial technology. In particular, there have been few studies on the effect of the experience of industrial technology leakage and enterprise scale(large enterprise, small and medium-sized enterprise) on achieving results in leakage prevention. Therefore, this study extracted factors affecting performance to prevent industrial technology leakage by analyzing previous related papers and to empirically analyze relationships with performance by applying the TAM model after classifying variables into the TOE framework by characterizing these properties.

• Journal of the Korean Electrochemical Society
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• v.18 no.4
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• pp.161-171
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• 2015

High-yield zinc germanium oxide ($Zn_2GeO_4$) and zinc tin oxide ($Zn_2SnO_4$) nanowires were synthesized using a hydrothermal method. We investigated the electrochemical properties of these $Zn_2GeO_4$ and $Zn_2SnO_4$ nanowires as anode materials of lithium ion battery and sodium ion battery. The $Zn_2GeO_4$ and $Zn_2SnO_4$ nanowires showed excellent cycling performance of the lithium ion battery, with a maximum capacity of 1021 mAh/g and 692 mAh/g after 50 cycles, respectively, with a high Coulomb efficiency of 98 %. For the first time, we examined the cycling performance of $Zn_2GeO_4$ and $Zn_2SnO_4$ nanowires for sodium ion batteries. The maximum capacity is 168 mAh/g and 200 mAh/g after 50 cycles, respectively, with a high Coulomb efficiency of 97%. These nanowires are expected as promising electrode materials for the development of high-performance lithium ion batteries as well as sodium ion batteries.

• Journal of Physiology & Pathology in Korean Medicine
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• v.29 no.1
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• pp.27-32
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• 2015

Streptococcus mutans triggers dental caries establishment by two major factors. One is synthesis of organic acids which demineralize dental enamel and the other is synthesis of glucans which mediate the attachment of bacteria to the tooth surface. In the present study, we evaluated the effect of the ethanol extracts of Aconitum koreanum (A. koreanum ) on the growth and acid production of S. mutans. Ethanol extracts of the A. koreanum showed concentration dependent inhibitory activity against the growth and acid production of S. mutans, and produced significant inhibition at the concentration of 0.016 mg/ml compared to the control groups (p<0.05). The extracts inhibited S. mutans adherence to hydroxyapatite treated with saliva, and cell adherence was repressed by 50%, 54% at the concentration of 0.063, 0.125 mg/ml. On the study of activation of glucosyltransferase which synthesizes water insoluble glucan form sucrose, the ethanol extract of A. koreanum showed remarkable inhibition over the concentration of 0.016, 0.031, 0.063 and 0.125 mg/ml (p<0.05). Especially on the concentration of 0.063, 0.125 mg/ml, the extracts suppressed the glucan synthesis by 100%. We analyzed the component of the extracts of A. koreanum. The results showed that the extract of A. koreanum had strong phenolic compound, glycosides and organic acids. These results suggest that A. koreanum may inhibit the caries-inducing properties of S. mutans, and which may be related with strong phenolic compound, glycosides and organic acids.

• Applied Chemistry for Engineering
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• v.27 no.2
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• pp.221-226
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• 2016

Production of eco-friendly and biologically harmless materials is strongly required in all industries. In particular, reducing volatile organic compounds in coating processes is extremely important to secure worker's safety. During recent two decades, extensive research works on water-borne polyurethane dispersion (PUD) have been continuously developed as an alternative to solvent-borne polyurethane. However, PUD was shown inferior mechanical properties to the organic solvent-borne polyurethane due to a limit to the molecular weight increase, which resulted in the limit of applications. To overcome this drawback, several approaches have been examined such as polymer blends and thermal/radiation induced crosslinking. Among these methods, the radiation curing system was suitable for industrialization because of the high crosslinking density and fast curing speed. In this study, we overcame the drawback for PUD via introducing benzophenone radiation curable units to PUD. We synthesized PUD films which possessed good dispersion in water for 30 days, increased Tg and Td more than $5^{\circ}C$ after UV curing film as well as improved young's modulus more than double.

• Journal of the Korean Institute of Intelligent Systems
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• v.16 no.6
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• pp.747-752
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• 2006

In this paper, the adaptive fuzzy sliding mode controller with two systems is designed. The existing sliding mode controller used to $approximation{\^{u}}(t)$ with discrete sgn function and sat function for keeping the state trajectories on the sliding surface[1]. The proposed controller decrease the disturbance for uncertain control gain and This paper is concerned with an Adaptive Fuzzy Sliding Mode Control(AFSMC) that the fuzzy systems ate used to approximate the unknown functions of nonlinear system. In the adaptive fuzzy system, we adopt the adaptive law to approximate the dynamics of the nonlinear plant and to adjust the parameters of AFSMC. The stability of the suggested control system is proved via Lyapunov stability theorem, and convergence and robustness properties ate demonstrated. Futhermore, fuzzy tuning improve tracking abilities by changing some sliding conditions. In the traditional sliding mode control, ${\eta}$ is a positive constant. The increase of ${\eta}$ has led to a significant decrease in the rise time. However, this has resulted in higher overshoot. Therefore the proposed ${\eta}$ tuning AFSMC improve the performances, so that the controller can track the trajectories faster and more exactly than ordinary controller. The simulation results demonstrate that the performance is improved and the system also exhibits stability.