• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1992.08a
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• pp.21-21
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• 1992

The paper is devoted to one of the branches tsunami. wave hydrodynamics. The theory of propagation, transformation and runup of tsunami waves taking into account the nonlinearity and the dispersion is exposed. The available data on real tsunamis are reviewed.(omitted)

• Communications for Statistical Applications and Methods
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• v.6 no.3
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• pp.821-830
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• 1999

In This paper we calculate the probabilities of binomial and Poisson distributions when n or${\mu}$ is large. Based on this calculation we consider the normal approximation to the binomial and binomial approximation to Poisson. We implement this approximation via CGI and dynamic graphs. These implementation are made available through the internet.

• Journal of the speleological society of Korea
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• no.8
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• pp.65-76
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• 1998

This article is based upon a talk given at the 1983 National Caving Conference explaining the types of personal computers available, their main features and how they could be used in connection with caving. There may be two groups of readers particularly interested in this subject, those covers with use of a computer who want some ideas on using it and others who want to know if getting a computer to use in connection with caving might be worth their while.

• Journal of Korea Multimedia Society
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• v.19 no.3
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• pp.567-572
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• 2016

N-screen is an emerging technology to support multimedia multicasting, content sharing and content mobility. N-screen service providers should obtain the technology that provides the highest quality content seamlessly. Distributed nature of WiMedia distributed-MAC protocol can provide full mobility support, and achieves seamless medium access method in contrast to IEEE 802.15.3. So, in this paper, WiMedia distributed-MAC protocol is adopted and an asynchronous multicast transmission (AMT) technology is proposed to enhance performance of seamless N-screen wireless service based on distributed-MAC. The ACK frame transmissions are not required for multicast transmissions. By using this property in AMT, if a device is a multicast receiver, its reserved time slots can be reserved by the other devices with 1-hop distance. Furthermore, each N-screen device broadcasts and shares the information including an order in asynchronous traffic reservations to reduce conflicts in determining the transmission order of asynchronous N-screen packets. Therefore, AMT scheme expands the number of time slots available and throughputs for multicast and asynchronous traffic reservations when comparing with the distributed-MAC standard system. N-screen communications based on distributed-MAC with the proposed AMT shows a new framework for realizing N-screen wireless service with the full content mobility.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.102-105
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• 1999

Mineralization of organic N is an important factor in determining the appropriate rate of organic matter application to paddy fields. A kinetic analysis was conducted for nitrogen mineralization of rice, barley, Chinese milk Ovetch (Astragalus sinicus L.; MV) and narrow leaf vetch straw in paddy soil. Nitrogen immobilization occurred rapidly and its rate increased in straw with high C/N ratio. The amount of nitrogen mineralization was rapid in the first year of rice-vetch cropping system. The rate constant (K) depended on the C/N ratio of organic matter. Mineralization of straw increased at high temperature. The amount of available N increment resulted in fast mineralization of straw, especially in rice and barley straw. Chinese milk vetch had the greatest mineralization rate at all temperatures and fertilization levels followed by narrow-leaf vetch. However, rice and barley straws with high C/N ratio immobilized the soil N at the initial incubation duration. Chinese milk vetch or narrow leaf vetch was not effectively mineralized in mixed treatments with rice or barley straw. The mineralization rate of organic matter was mostly affected by the C/N ratio of straw and temperature of incubation. Organic matter with low C/N ratio should be recommended to avoid the immobilization of soil N and the increasing mineralization rate of straw.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.6
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• pp.407-416
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• 2003

Although the requirement and optimum soil level of Si for oriental melon are still not well understood, silicate fertilizer is commonly applied to the oriental melon in plastic film houses where soil silicate level is relatively high. In this research the effects of silicate fertilizer on growth, fruit yield and fruit quality of oriental melon, and soil properties were investigated in plastic film house where the soil available silicate was $212mg\;SiO_2\;kg^{-1}$. Silicate fertilizer was applied in the rates of 100, 200, and $300kg\;10a^{-1}$. The application of silicate fertilizer could not increase the early growth of oriental melon, and also the fruit yield and quality were not different among the treatments. Available Si and P contents in soils and also Si and P contents in leaf of oriental melon of the different treatments were not significantly different. In the relationship between total Si in oriental melon leaf and soil silicate extracted by 1 N sodium acetate, optimum soil available silicate level for oriental melon was found to be around $100mg\;SiO_2\;kg^{-1}$. These results indicate that the additional silicate fertilization in soils of available silicate higher than $100mg\;SiO_2\;kg^{-1}$ is unnecessary, and such application of silicate can not have any beneficial effect on the growth and fruit yield of oriental melon.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.2
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• pp.50-59
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• 2006

In this paper, We are going to propose the fire protection system using CAN(Controller Area Network). The larger, higher and deeper buildings an, the more dangerous people are when fire happens. We should be aware of the problems of prior fire protection system. Therefore, we construct the embedded system based on CAN communication that is capable of N to N communication, and build independent fire protection system. If the fire is occurred on the building, the problem is that how fast we can detect the fire and put it on by using available system, this is major factor that reduces damage of our wealth. Therefore in this studies, We would like to design more stable system than current system. This system is based on CAN communication which is available N to N communication constructs and designed to compensate for each fault, so that our aim is to reduce the wires of system, cost of installation and to suppose future type fire protection system.

• The Korean Journal of Ecology
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• v.10 no.3
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• pp.129-138
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• 1987

In a red pine (Pinus densiflora) forest, changes of pH, electric conductivity, total carbon, total nitrogen, available phosphate and available potassium in soil and runoff have been studied at intervals for 1 year after early spring fire. Phytimasses of herb and shrub were measured following the current and the subsequent year. The pH, E.C., total nitrogen and phosphate of soil in burned site wee 1.1, 1.5, 1.6 and 2.0 times higher than in unburned site, respectively. But potassium showed no significant difference. A rise in pH, E.C., and total nitrogen in burned site were maintained throught the study period while phosphate maintained 4 months after the fire. The E.C., total carbon, $NO_2-N$ and $NH_4-N$ of runoff in burned site were 1.3, 1.3, 1.3 and 29.0 times higher than in unburned site, respectively, while $NO_3-N$ in unburned site was 4 times higher than in burned site. In burned site, phytomasses of herb and shrub were 148 and 33% of unburned site in a current year and 107 and 51% in a subsequent year, respectively. The considerable amount of increase in soil nutrient after the fire was conserved by the uptake of the fast regrowing plants and by the immobilization of $NH_4=N$.

• Journal of Applied Biological Chemistry
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• v.49 no.1
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• pp.28-32
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• 2006

Effect of organic-C on immobilization and nitrification patterns in acidic soil was examined during 20 weeks incubation period to verify if organic amendments such as composted material can increase soil retention of N by stimulating microbial immobilization of $NH_4^+$. Four treatments were laid out: control without fertilizer N and glucose (treatment code: S), ammonium sulfate (SN), ammonium sulfate with single glucose at the commencement (0 week) of incubation (SNG), and ammonium sulfate with double glucose at 0 and 4 weeks of incubation (SNGG). Glucose application (SNG) significantly increased microbial immobilization of $NH_4^+$ within 1 week of incubation over SN. Immobilization was followed by remineralization thereafter; however, second-application of glucose (SNGG) restored $NH_4^+$ immobilization. At the same time, nitrification was significantly inhibited by glucose application as indicated by consistently low $NO_3^-$ concentration in SNG and SNGG soils, suggesting that microbial assimilation of $NH_4^+$ is predominant compared to nitrification when available C-source is abundant. These results suggest application of chemical fertilizer-N with organic amendment would have beneficial effect on soil-N retention and environmental conservation by reducing production of $NO_3^-$ which is likely to be lost through leaching or denitrification.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.06a
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• pp.119-126
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• 1999

The rolling fatigue lives (RFL) of five kinds of silicon nitride balls were investigated. Four kinds of Si$_3$N$_4$ balls were fabricated using different raw materials, sintering aids and sintering conditions, Commercially available Si3N4 ball was also studied for comparison. All the balls were finished up to the dimensional accuracy of Grade 10 defined in KS B 2001 (Steel Balls for Ball Bearings) with a size of 9.525mm. RFL tests were then conducted under the initial theoretical maximum contact stress 6.38 GPa and the spindle speed 10,000 rpm. Gear oil was provided by oiled race as lubricant. The results of RFL test indicated the prerequisitic conditions for the long rolling life of Si$_3$N$_4$ball : (1) the high density, (2) mjcrostructures consisted of small uniformly distributed grains, (3) little glassy phase in grainboundary, and (4) little crystalline phase and secondary phase that induces residual thermal stress due to the differences of thermal expansion coefficient with Si$_3$N$_4$Phase.