• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.3
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• pp.57-69
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• 2011

This study examined the relationship between Phragmites australis' growth and sediment properties at mud tidal flat of Donggum-ri, Gilsang-myeon, Gangwha-gun, Incheon city. Field survey was carried out from May, 2010 to October, 2010. Water content, soil texture, electric conductivity and water table depth for sediment, density, height, dry weight and flowering for P. australis were examined at several plots from the starting point (the coastal embankment) to the end point of the two populations. The result was as follows. Firstly, the water table increased along distance from the embankment at one line (N-line) but was similar at the other line (S-line) in a P. asustralis population. Water tables were higher out of than within a P. australis population at two populations. Secondary, in N-line, the height and dry weight of P. australis decreased along the distance from embankment but, in S-line, those were similar in its population. P. australis' growth was dependent on electric conductivity at lower layer (water table level) rather than upper one (the surface). Thirdly, density of P. australis changed during growing season and was similar in a population, except for the end point of patch. In summary, the growth and distribution of P. australis were dependent on salt content of tidal flat's sediment (water table level) and this was affected by fresh water of the inland.

• International Journal of Contents
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• v.5 no.1
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• pp.51-55
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• 2009

In this paper, we present a structure of personalized e-Learning system to study for a test formalized by uniform multiple-choice using on/off line mixed estimations as is the case of Driver :s License Test in Korea. Using the system a candidate can study toward the license through the Internet (and/or mobile instruments) within the personalized concept based on IRT(item response theory). The system accurately estimates user's ability parameter and dynamically offers optimal evaluation problems and learning contents according to the estimated ability so that the user can take possession of the license in shorter time. In order to establish the personalized e-Learning concepts, we build up 3 databases and 2 agents in this system. Content DB maintains learning contents for studying toward the license as the shape of objects separated by concept-unit. Item-bank DB manages items with their parameters such as difficulties, discriminations, and guessing factors, which are firmly related to the learning contents in Content DB through the concept of object parameters. User profile DB maintains users' status information, item responses, and ability parameters. With these DB formations, Interface agent processes user ID, password, status information, and various queries generated by learners. In addition, it hooks up user's item response with Selection & Feedback agent. On the other hand, Selection & Feedback agent offers problems and content objects according to the corresponding user's ability parameter, and re-estimates the ability parameter to activate dynamic personalized learning situation and so forth.

• Journal of applied mathematics & informatics
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• v.33 no.1_2
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• pp.185-191
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• 2015

This paper considers a discrete-time buffer system with session-based arrivals, an infinite storage capacity and one unreliable output line. There are multiple different types of sessions and the output line is governed by a finite state Markov chain. Based on a generating functions approach, we obtain an exact expression for the mean buffer content.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.11a
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• pp.265-270
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• 2000

Injection molding is a very important industrial process for the manufacturing of plastics objects. During an injection molding process of composites, the fiber-matrix separation and fiber orientation are caused by the flow of molten polymer/fiber mixture. As a result, the product tends to be nonhomogeneous and anisotropic. Hence, it is very important to clarify the relations between separation· orientation and injection molding conditions. So far, there is no research on the measurement of fiber orientation using image processing. In this study, the effects of fiber content ratio and molding condition on the fiber orientation-angle distributions are studied experimentally. Using the image processing method, the fiber orientation distribution of weld-line parts in injection-molded products is assessed. And the effects of fiber content and injection molding conditions on the fiber orientation functions are also discussed

• YAKHAK HOEJI
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• v.44 no.5
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• pp.455-462
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• 2000

To investigate how the aqueous extracts of Epimedium koreanum Nakai (EK) affects pigmentation of skin, the aqueous extract of EK at various concentrations were incubated with 1 $\times$ 10$^{5}$ melanoma cells per well for 72 h. The morphology and number of cell line were not changed, but the aqueous extract of EK increased the tyrosinase activity and the content of melanin polymer in the cell line. These results indicate that the aqueous extract of EK promotes melanogenesis of Bl6 mouse melanoma cell line.

• Journal of Multimedia Information System
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• v.2 no.1
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• pp.163-170
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• 2015

Many overlay texts are artificially superimposed on the broadcasting videos by humans. These texts provide additional information to the audiovisual content. Especially, the overlay text in news videos contains concise and direct description of the content. Therefore, it is most reliable clue for constructing a news video indexing system. To make the automatic person indexing of interview video in the TV news program, this paper proposes the method to only detect the name text line among the whole overlay texts in one frame. The experimental results on Korean television news videos show that the proposed framework efficiently detects the overlaid name text line.

• Smart Structures and Systems
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• v.5 no.3
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• pp.209-221
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• 2009

A control algorithm for seismic protection of building structures based on the theory of variable structural control or sliding mode control is presented. The paper focus in the design of sliding surface. A method for determining the sliding surface by pole assignment algorithm where the poles of the system in the sliding surface are obtained on-line, based on the frequency content of the incoming earthquake signal applied to the structure, is proposed. The proposed algorithm consists of the following steps: (i) On-line FFT process is applied to the incoming part of the signal and its frequency content is recognized. (ii) A transformation of the frequency content to the complex plane is performed and the desired location of poles of the controlled structure on the sliding surface is estimated. (iii) Based on the estimated poles the sliding surface is obtained. (iv) Then, the control force which will drive the response trajectory into the estimated sliding surface and force it to stay there all the subsequent time is obtained using Lyapunov stability theory. The above steps are repeated continuously for the entire duration of the incoming earthquake. The potential applications and the effectiveness of the improved control algorithm are demonstrated by numerical examples. The simulation results indicate that the response of a structure is reduced significantly compared to the response of the uncontrolled structure, while the required control demand is achievable.

• Magazine of the Korean Society of Agricultural Engineers
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• v.38 no.2
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• pp.123-132
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• 1996

The purpose of this study was to clarify the reflectance of soil and plant in order to extract the soil and vegetation informations using the satellite remote sensing data. The influence of soil moisture content and vegetation cover rate on the soil reflectance, and the relationship between vegetation reflectence and its vitality were discussed. The results obtained in this study were summarized as follows; I) The soil reflectance($R_{0.65}$) of wavelength ($0.65{\mu}m$) was closely related to the reflectance((($IR_{0.85}$) of wavelength $0.85{\mu}m$. This relationship could be expressed by soil line. 2) A point on the soil line was affected by the soil moisture ratio and the organic matter content. 3) The vegetation cover rate was formulated in terms of soil and vegetation reflectance at wavelengths pf $0.65{\mu}m$($R_{0.65}$) and ($0.85{\mu}m$) (($IR_{0.85}$). 4) The vegetation reflectence was strongly influenced by its vitality, which was related to the moisture content and the chlorophy [[-a concentration.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.282-282
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• 2017

The many factors such as sugar content, moisture, type of bacteria which predominate, buffering capacity, packing and sealing are known to be associated with silage fermentation quality. Among the sugar content are particularly important, because effective silage ensiling relies on the fermentation of sugar content to lactic acid by lactic acid bacteria. Sugar content is also known to affect the protein utilization of rumen. This study was conducted to observe the effect of water soluble carbohydrates on fermentation characteristics and in vitro digestibility of whole crop wheat silage. This experiment was used standard cultivars (Cheongwoo, Hordeum balgare L) and solid breeding line of whole crop wheat. The materials harvested at the 30 after heading day and chopped for making silage, and using this silage carried out in vitro digestibility for 6, 12, 24 and 48 hours. For the feed value, crude protein, NDF, ADF contents showed slightly higher than the before ensiling and TDN contents were slightly lower compared to the before ensiling, but did not show the significantly different. For the sugar contents, fructose and glucose contents were decreased in the after ensiling compared to the before ensiling, there were more reduced at the containing high sugar content wheat. The pH value was lower at containing high sugar content wheat. lactic acid content was significantly higher at the containing high sugar content wheat. Therefore, there was profitable to the production of high quality wheat silage at the higher the sugar content. In in vitro digestibility test, containing high sugar content HW34line showed significantly higher dry matter digestibility at 6 and 12 hours of incubation and amount of NH3-N lower other line in all incubation time. Therefore, there was profitable to the production of high quality wheat silage at the higher the sugar content.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.4
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• pp.1-7
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• 2006

Injection molding is a very important industrial process for the manufacturing of plastics objects. During an injection molding process of composites, the fiber-matrix separation and fiber orientation are caused by the flow of molten polymer/fiber mixture. As a result, the product tends to be nonhomogeneous and anisotropic. Hence, it is very important to clarify the relations between separation orientation and injection molding conditions. So far, there is no research on the measurement of fiber orientation using image processing. In this study, the effects of fiber content ratio and molding condition on the fiber orientation-angle distributions are studied experimentally. Using the image processing method, the fiber orientation distribution of weld-line in injection-molded products is assessed. And the effects of fiber content and injection mold-gate conditions on the fiber orientation are also discussed.