• Fire Science and Engineering
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• v.22 no.5
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• pp.9-21
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• 2008

The objective of this study is to suggest a fire prevention measure for suppressing and preventing loss of precious human lives and property damages. The characteristics of incendiary fire are analyzed in terms of fire engineering to review a plan for promoting for coping with the risk. In this study, a medical aspect such as mental and psychological analysis of the motive or act of an incendiary and legal and administrative problems such as the penalty for the incendiary are not included in the scope of the study. Fire statistics data of Korea, Japan, and U.S. are investigated for analysis of actual states of incendiary fire occurrences. In particular, to quantitatively recognize the burning characteristics of common fire and the burning characteristics of incendiary fire, a fire model test and computer simulation were performed. And a plan for promoting the optimal incendiary fire prevention measure were suggest.

• Research in Plant Disease
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• v.13 no.1
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• pp.1-5
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• 2007

Major diseases of tobacco and farmer's control practices were surveyed in the Kyeongbuk province area from 2005 to 2006. Mosaic caused by potato virus Y and bacterial wilt caused by Ralstonia solanacearum were most severe during the harvest season. Compared with the disease occurrence of ten years ago, the damage by tobacco mosaic virus reduced but bacterial wilt increased. These changes in the disease occurrences may probably be due to releasing the resistant tobacco cultivar to the mosaic virus but susceptible to the bacterial wilt pathogen. More than thirty percentage of the farmers have misused fungicides and also have applied the continuous mono-cropping system for more than ten years, and have chosen the incorrect crops for the rotation.

• The Korean Journal of Applied Statistics
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• v.27 no.2
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• pp.277-290
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• 2014

We analyzed binary landslide data from the Boeun area with logistic regression. Since the number of landslide occurrences is only 9 out of 5000 observations, this can be regarded as a rare event data. The main issue of logistic regression with the rare event data is a serious bias problem in regression coefficient estimates. Two bias correction methods were proposed before and we quantitatively compared them via simulation. Firth (1993)'s approach outperformed and provided the most stable results for analyzing the rare-event binary data.

• The Korean Journal of Applied Statistics
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• v.30 no.5
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• pp.759-774
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• 2017

Earthquake concerns have grown after a remarkable earthquake incident on September 12th, 2016 in Gyeongju, Korea. Earthquake forecasting is gaining in importance in order to guarantee infrastructure safety and develop protection policies. In this paper, we adopt a power-law distribution model to fit past earthquake occurrences in Korea with various historical and modern seismological records. We estimated power-law distribution parameters using empirical distributions and calculated the future probabilities for large earthquake events based on our model. We provide the probability that a future event has a larger magnitude than given levels, and the probability that a future event over certain levels will occur in a given period of time. This model contributes to the assessment of latent seismological risk in Korea by estimating future earthquake probabilities.

• Biomolecules & Therapeutics
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• v.14 no.1
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• pp.19-24
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• 2006

Atrial chambers serve as mechanosensory systems during the haemodynamic or mechanical disturbances, which initiates arrhythmia. Atrial myocytes, lacking t-tubules, have two functionally separate sarcoplasmic reticulums (SRs): those at the periphery close to the surface membrane, and those at the cell interior (center) not associated with the membrane. To explore possible role of fluid pressure (FP) in the regulation of atrial local $Ca^{2+}$ signaling we investigated the effect of FP on subcellular $Ca^{2+}$ signals in isolated rat atrial myocytes using confocal microscopy. FP was applied to whole area of single myocyte with pressurized automatic micro-jet (200-400 $mmH_2O$) positioned close to the cell. Application of FP enhanced spontaneous occurrences of peripheral and central $Ca^{2+}$ sparks with larger effects on the peripheral release sites. Unitary properties of single sparks were not altered by FP. Exposure to higher FP often triggered longitudinal $Ca^{2+}$ wave. These results suggest that fluid pressure may directly alter excitability of atrial myocytes by activating $Ca^{2+}$-dependent ionic conductance in the peripheral membrane and by enhancing spontaneous activation of central myofilaments.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1619-1624
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• 2007

The rainfall frequency estimations are critical in the design of hydraulic structures (such as bridges and culverts) to ensure that they are built economically and safely. In other words, they are not over designed or under designed. However one of the main assumptions in the creation of these analysis is that the rainfall data for a site is stationary. That is, climatic trends and variability in a region have negligible effects on the curves. But as has been proved in recent history, climatic variability and trends do exist and their effects on precipitation have not been negligible. Increasing occurrences of the El Nino phenomenon have lead to droughts and floods around the world, and long term trends in rainfall, both increases and decreases, have been seen in all regions across Korea. The purpose of this paper is to investigate and evaluate impacts of ENSO on rainfall characteries and rainfall frequency estimations in Korea. In this paper, The available rainfall data were categorized into Warm(EL Nino), Cold(La Nina), Normal episodes based on the Cold & Warm Episodes by Season then 50 years of daily rainfall data were generated for each episodic events(EL Nino, La Nina)

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.3
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• pp.217-223
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• 2014

With precise sensor position, attitude element, and imaging resolution, a simulated geospatial image can be generated. In this study, a satellite image is simulated using SPOT ortho-image and global elevation data, and the geometric similarity between original and simulated images is analyzed. Using a SPOT panchromatic image and high-density elevation data from a 1/5K digital topographic map data an ortho-image with 10-meter resolution was produced. The simulated image was then generated by exterior orientation parameters and global elevation data (SRTM1, GDEM2). Experimental results showed that (1) the agreement of the image simulation between pixel location from the SRTM1/GDEM2 and high-resolution elevation data is above 99% within one pixel; (2) SRTM1 is closer than GDEM2 to high-resolution elevation data; (3) the location of error occurrence is caused by the elevation difference of topographical objects between high-density elevation data generated from the Digital Terrain Model (DTM) and Digital Surface Model (DSM)-based global elevation data. Error occurrences were typically found at river boundaries, in urban areas, and in forests. In conclusion, this study showed that global elevation data are of practical use in generating simulated images with 10-meter resolution.

• Economic and Environmental Geology
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• v.13 no.4
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• pp.205-213
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• 1980

Stannite is mainly found in hypothermal ore deposits, whereas mawsonite and stannoidite occur characteristically with bornite and chalcopyrite in subvolcanic (xenothermal) ore deposits. Mawsonite always shows the replacement on the rims of stannoidite grains or along the grain boundaries of stannoidite, bornite and chalcopyrite. In the Tada mine, Japan, the following mineral assemblages of the Cu-Fe-Sn-S minerals were observed. 1) bornite-stannoidite; 2) stannoidite-chalcopyrite; 3) stannite-chalcopyrite; 4) bornite-mawsonite-stannoidite; 5) bornite-stannoidite-chalcopyrite; 6) mawsonite-stannoidite-chalcopyrite; 7) stannoidite-stannite-chalcopyrite; 8) bornite-mawsonite-stannoidite-chalcopyrite The heating and D.T.A. experimental results indicate that natural stannoidite containing 3 weight percent of zinc decomposes to bornite, stannite and chalcopyrite at above $500^{\circ}C$, whereas zinc-free synthetic stannoidite is stable up to $800^{\circ}C$. The stability temperature of zincian stannoidite depends on the zinc content. Mawsonite is stable at temperatures below $390^{\circ}C$ and decomposed to stannoidite, bornite and chalcopyrite above it. According to the sulfur fugacity determination by the electrum tarnish method the univariant assemblage of mawsonite, bornite, stannoidite and chalcopyrite requires a higher sulfur fugacity than that of bornite, stannoidite and chalcopyrite assemblage.

• Applied Microscopy
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• v.46 no.2
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• pp.83-88
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• 2016

Structural differentiation of the connective stalk in giant duckweed, Spirodela polyrhiza, was examined to reveal the anatomical and ultrastructural characteristics within reduced shoot. The study focuses primarily on structural features of the connective stalk (CT), which connect offspring to their mother fronds. Photoautotrophic offspring fronds remained connected by stalks to mother fronds in the reproductive pockets until separation. The CT originated from the meristematic region of the abaxial frond and joined the fronds laterally with two abscission layers. The most notable features of the CT were polymorphic mitochondria, random occurrences of fibrillar structures in intercellular spaces, and great variability in cell wall thickness. Vascular tissues in CTs were highly reduced, demonstrating only a central vascular strand. Grana with 2 to 4 thylakoids and starch grains were found in the chloroplasts. A chlorophyll assay indicated high chlorophyll concentrations in daughter fronds and low concentrations in CTs. The frond and CT, while physically connected to each other, functioned independently. Despite great reduction in S. polyrhiza, the CT has proven to be very efficient for separating offspring from the mother frond, which lends to its capacity for rapid vegetative reproduction. The ultrastructural aspects of CTs in S. polyrhiza were characterized for the first time in this study.

• Journal of Internet Computing and Services
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• v.8 no.2
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• pp.89-94
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• 2007

Even though lots of research have been doing about spam mail blocking technologies and their systems, the emergence of spam mails of new types causes the spam mail filtering rate to decrease and the occurrences of false-positive mails to increase. Therefore, existing spam mail filtering algorithms suffer from increasing load to be processed and decreasing reliability in spam mail blocking systems due to the shortage of newly developed algorithms and their research. This paper presents the Fit-FA Finder which is able to select appropriate algorithms to be applied and their procedures, and the development of the SMBC platform. The Fit-FA Finder is developed and implemented in the SMBC platform in which recovering process based on privacy information is employed for false-positive mails