• Journal of the Korean Institute of Landscape Architecture
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• v.22 no.2
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• pp.133-157
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• 1994

This study was executed to find out the succession stage and the ecological niche of Lindera erythrocarpa Markino. Four sites were selected by field investigation. They are Jeondungsa and Jeongsusa of Kanghwa Island, Mt. Suri of Anyang and Mt. Gaya of Chungcheongnamdo. They located in the region which have the similar temperature with Seoul region or lower average temperature for winter than that of adjacent Seoul. In the four sites, L, erythrocarpa was appeard in canopy layer at L. erythrocarpa community in Jeondungsa, L. erythrocarpa-Q. serrata, Z. serrata-L. erythrocarpa community in Jeongsusa, Castanea crenata-L, erythrocarpa community, L. erythrocarpa-Q. serrata community in Mt. Gaya and in the rest of the sites, it lives in subtree and shrub layer. And in the four sites but Jeongsusa area, it correspond with Chang(1991)'s study that L. erythrocarpa is dominant species in the site impacted by human. L. erythrocarpa lives with Quercus spp. such as Q. serrata, Q. variabilis, Q. mongolica and Carpinus laxiflora but it's presumably a passing phenomena.

• Journal of Internet Computing and Services
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• v.2 no.4
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• pp.83-90
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• 2001

Q+-reader, an E-Book reader system for XML based contents is introduced, The system is developed for the embedded platform, called Q+, which targets for the digital home electronics systems, The system supports XML contents and CSS based styling as described in Open e-book standard. The system renders the e-book contents for users, sc the contents are secured for a proper use. This will found an essential part of business infra for electronic books with copyright protection, The system was developed in Java language to be used in various platform;, and has an open architecture to be reusable for other standards as well.

• Journal of Plant Biology
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• v.33 no.3
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• pp.173-182
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• 1990

To investigate the structure of the plant community structure of Mt. Yongmun in Kyonggi-do, fifty-four plots were set up by the clumped sampling method. The classification by TWINSPAN and DCA ordination were applied to the study area in order to classify them into several groups based on woody plant and environmental variables. By both techniques, the plant community were divided into two groups by the aspect. the dominant species of south aspect were Pinus densiflora, Quercus aliena, Q. mongolica, Carpinus laxiflora and of north aspect were Q. ongolica, Fraxinus rhynchophylla. The successional trends of tree species in south aspect seem to be from P. densiflora through Q. serrata, Q. aliena, A. mongolica to C. laxiflora. As a result of the analysis for the relationship between the stand scores of DCA and environmental variables, they had a tendency to increase significantly from the P. densiflora and Q. mongolica community to C. laxiflora and F. rhynchophylla community that was the soil moisture, the amount of soil humus and soil pH.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.12
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• pp.5958-5967
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• 2012

The purpose of this study is to build a bioethical foundation for Paramedic students by identifying and explaining the subjective types and structures of the students' perception on abortion using Q-methodology. Forty statements as a Q sample are selected from the literature and in-depth interview, and P-sample consists of twenty nine junior Paramedic students. The collected data is analyzed by using a QUANL program. The analysis identified three types of the paramedic students' perception on abortion: The fetus-oriented decision type, The mother-oriented active decision type(n=15), The Type(n=9),and mother-oriented passive decision type(n=5). The three factors all had eigenvalues greater than 1.0 and explained 61.3% of the variance in responses. Based on the result of this research, type 1 focuses on the importance of life, whereas other types seem to demonstrate a self-centered mindse that puts more importance on self than the fetus. Therefore, bioethics courses, especially ones that deal with abortion, are crucial to those paramedic students who handle the lives of others.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.468-476
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• 2019

This paper presents the means of improving the strength of LTV's FRP structure for resolve and prevent quality problems. LTV secures enough kerb weight by applying FRP materials at hood and rear van assembly. However, because of FRP's inherent limitations, many initial quality problems such as crack at connections have occurred. Moreover, hood assy' is concerned about fall of endurance, because hood assy' have operated in abnormal condition. Therefore, this study executes lamination structure optimizations of FRP structure for improving bending strength. As a results, hood and rear van's bending strength at connections is improved 8.1 times and 1.5 times, respectively. Also hood assy's plate secures endurance life and improve 1.7 times of critical load about abnormal operating conditions through 1.4 times improvement of bending strength.

• Journal of Korean Association for Spatial Structures
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• v.21 no.1
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• pp.79-86
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• 2021

Control performance of a smart tuned mass damper (TMD) mainly depends on control algorithms. A lot of control strategies have been proposed for semi-active control devices. Recently, machine learning begins to be applied to development of vibration control algorithm. In this study, a reinforcement learning among machine learning techniques was employed to develop a semi-active control algorithm for a smart TMD. The smart TMD was composed of magnetorheological damper in this study. For this purpose, an 11-story building structure with a smart TMD was selected to construct a reinforcement learning environment. A time history analysis of the example structure subject to earthquake excitation was conducted in the reinforcement learning procedure. Deep Q-network (DQN) among various reinforcement learning algorithms was used to make a learning agent. The command voltage sent to the MR damper is determined by the action produced by the DQN. Parametric studies on hyper-parameters of DQN were performed by numerical simulations. After appropriate training iteration of the DQN model with proper hyper-parameters, the DQN model for control of seismic responses of the example structure with smart TMD was developed. The developed DQN model can effectively control smart TMD to reduce seismic responses of the example structure.

• Korean Journal of Environment and Ecology
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• v.9 no.1
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• pp.15-29
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• 1995

To investigate plant community structure of Uiryung valley, Harujae valley, Kugi valley, Songchu valley, Tobongsan valley in Bukhansan National Park, each thirty eight, forty, twenty six. twenty eight, thirty six plots (plot size 100$m^2$) were set up and surveyed. The surveyed data were integrated and classification by TWINSPAN and DCA ordination techniques were applied to the study area. The plant community were divided into nine groups in seventy nine plots by TWINBPAN and the dividing groups were Carpinus laxiflora community(I), Quercus mongolica community(II), Pinus densiflora community(III), Q. mongolica-P. densiflora community(IV) Q. mongolica-Q. serrata- Prunus sargentii community(V), Q. mongolica Q. variabilis community(Ⅵ), Robinia pseudoacacia-Q. serrata community(Ⅶ). P. rigida-Q. serrata community(Ⅷ), Q. mongolica- Q. variabilis- Styrax obassia community(Ⅸ). So the successional trends of tree species at the natural forest seem to be from P. densiflora to Q. mongolica and at the artificial forest seem to be from R. pseudoacacia, P. rigida to Q. acutissima, Fraxinus rhynchophylla in canopy layer And in the subtree and shrub layer, it wag supposed that from Deotzia prunifolia, Rhus trichocarpa. Rhododendron yedoense var. poukhasleilse, Euonymus oxyphyllous to Magnolia sieboldii, Acer psuedo-sieboldianum, Lindera obtusiloba. In comparing successional trends with past study, it was postulated that successtion is not progressed by human disturbance and soil acidification by the air pollution.

• Applied Chemistry for Engineering
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• v.7 no.2
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• pp.379-386
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• 1996

Photosensitive compound, 1-methyl-4-[2-(4-diethylacetylphenyl)ethenyl] pridinium methosulfate(SbQ-A salt), was synthesized from dimethyl sulfate, terephthalaldehyde mono-(diethylacetal) and 4-picoline. SbQ-A salts were reacted with poly(vinyl alcohol)s, (PVA) in aqueous solution with phosphoric acid as catalyst to give photosensitive PVA-SbQ with different SbQ content and molecular weight. Relative photosensitivity of PVA-SbQ was determined by gray scale(GS) method. The rotative sensitivity of PVA-SbQ increased with increasing amount of bound SbQ in the case of high molecular weight(MW=77,000-79,000g/mol) as substrate and decreased with decreasing molecular weight of PVA with about constant(1.3mol%) amount of bound SbQ. The most sensitive polymer was obtained when SbQ group content in PVA-SbQ reached about 2.63mol% in the case of high molecular weight(77,000-79,000g/mol) PVA. This sample showed 90 times greater sensitivity than dichromated PVA as reference photosensitive system. PVA-SbQ photosensitive polymer synthesized was applied to the photolithographic screening process of phosphor on the panel of cathode ray tube(CRT). Phosphor slurry was made with PVA-SbQ, phosphor, a small amount of surfactant and other additives using water as medium. The slurry was coated onto panel, dried by heater, exposed to UV light and then developed by distilled water. When a small amount of cationic surfactant such as cetyltrimethylammonium chloride was used in the slurry formulation, the sharpness of phosphor pattern was equal to or better than that of dichromated PVA photosensitive polymer system used currently.

• Geophysics and Geophysical Exploration
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• v.12 no.2
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• pp.199-207
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• 2009

From 329 earthquake data in the Korean Peninsula, we separated the intrinsic and scattering quality factor ($Q_i^{-1}$ and $Q_s^{-1}$) using the Multiple Lapse Time Window Analysis (MLTW) method. For the homogeneous velocity structure, $Q_i^{-1}$ reduces the amplitudes of both direct and coda waves; $Q_s^{-1}$ diminishes the direct wave amplitude but enlarges the coda wave amplitude. Based on this phenomenon, MLTW method analytically derives theoretical curves and obtains $Q_i^{-1}$ and $Q_s^{-1}$ by least square fit with observation curves. This study is the first approach for the seismic stable region by MLTW method, and show that $Q_i^{-1}$ and $Q_s^{-1}$ in the Korean Peninsula are very low at lower than frequencies of 5 Hz. This low value seems to be related to the inactive tectonism of the Korean Peninsula.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.10
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• pp.2065-2071
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• 2011

The external quality factor ($Q_e$) is controlled by coupling condition between resonator and input/output ports in design of microwave filter. In this paper, we represent extracting method of external quality factor using phase response for resonator with input/output ports according to position of feed line from microstrip line resonator. The results regarding to position, coupling gap and line width for tapped line and coupled line structure are represented, and we got the exact $Q_e$ value from the this method. This results will be applied to coupled resonator filter design.