• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.112-112
• /
• 2017

Rice blast caused by Magnaporthe oryzae is one of the most serious diseases that affect the quantity and quality of rice production. The use of resistant rice varieties would be the most effective way to control the rice blast. However R gene incorporation into the rice variety takes time and pathogen could overcome the R gene effects after for a while. For monitoring the rice blast resistance gene distribution in Korean varieties, the four major blast resistance genes against M. oryzae were screened in a number of Korean rice varieties using molecular markers. Of the 120 rice varieties tested, 40 were found to contain the Pi-5 gene, 25 for the Pi-9 gene, 79 for Pi-b and 40 for the Pi-ta gene. None of these rice varieties includes tested 4 R genes. 3 R genes combination, Pi-5/Pi-9/Pi-b, Pi-5, Pi-9.Pi-ta, or Pi-9/Pi-b/Pi-ta were found in 12 varieties, the rice blast disease severity were showed as resistant in the rice verities containing Pi-9/Pi-b/Pi-ta R genes combination, respectively. Also pathogenic diversity of M. oryzae isolates collected in the rice field from 2004 to 2015 in rice field in Korea were analyzed using rice blast monogenic lines, each harboring a single blast resistance gene. Compatibility of blast isolates against rice blast monogenic lines carrying the resistance genes Pi5, Pi9, Pib, and Piz showed dynamic changes by year. It indicates that pathogen has high evolutionary potential adapted host resistances to increase fitness and would lead to rice blast resistance bred into the cultivar becoming ineffective eventually.

• BMB Reports
• /
• v.34 no.5
• /
• pp.446-451
• /
• 2001

The interaction of cytochrome c with binary phospholipid mixtures was investigated by solid-state $^2H$- and $^{31}P$-NMR. To examine the effect of the interaction on the glycerol backbones, the glycerol moieties of phosphatidylcholine (PC), and cardioliph (CL) were specifically deuterated. On the binding of cytochrome c to the binary mixed bilayers, no changes in the quadrupole splittings of each of the components were observed for the PC/PG, PE/CL and PE/PG liposomes. In contrast, the splittings of CL decreased on binging of protein to the PC/CL liposomes, although those of PC did not change at all. This showed that cytochrome c specifically interacts with CL in PC/CL bilayers, and penetrates into the lipid bilayer to some extent so as to perturb the dynamic structure of the glycerol backbone. This is distinctly different from the mode of interaction of cytochrome c with other binary mixed bilayers. In the $^{31}P$-NMR spectra, line broadening and a decrease of the chemical shift anisotropy were observed on the binding of cytochrome c for all binary mixed bilayers that were examined. These changes were more significant for the PC/CL bilayers. Furthermore, the line broadening is more significant for PC than for CL in PC/CL bilayers. Therefore, it can be concluded that with the polar head groups, not only CL but also PC are involved in the interaction with cytochrome c.

• Journal of Korea Multimedia Society
• /
• v.11 no.8
• /
• pp.1129-1137
• /
• 2008

E-learning as a new education trend is being applied not only to cyber school but also various education fields such as employee training for companies or interactive learning for consumers. Users of the E-learning can take online tests individually anywhere, to evaluate their achievement level. Because users who are taking the online tests may show their own IDs or passwords to others, the possibility of cheating is very high. Therefore, it is very important to authenticate the users. In this paper, we propose an adaptive-keyboard authentication method which depends on user behavior patterns through the use of IDs and passwords. This method does not need any additional devices or special effort. An adaptive method to update patterns in which IDs and passwords are entered was previously suggested and this new method has proved to be better than previous methods through simulations and implementation.

• Polymer(Korea)
• /
• v.38 no.2
• /
• pp.225-231
• /
• 2014

The rheological properties of highly concentrated polymer bonded explosive simulant were studied by using poly(ethylene-co-vinyl acetate) with 30 and 60% vinyl acetate (VA) content as a binder, respectively. Calcium carbonate and Dechlorane, whose physical properties are similar to resarch department explosive (RDX)'s, were used as fillers. The suspensions were mixed in a batch melt mixer and it was possible to fill 75 v% at maximum. From dynamic mechanical analysis, Dechlorane showed higher interaction with binder resins than that with calcium carbonate fillers. The effects of microstructural change on the rheological properties of the suspensions were investigated by a plate-plate rheometer with constant shear rate and constant shear stress modes, respectively. The theoretical maximum packing fraction of EVA31/Dechlorane suspension obtained from Krieger-Dougherty equation was 70 v% and it was thought that 2000 Pa was proper shear stress condition for this melt processing.

• Journal of KIISE
• /
• v.45 no.3
• /
• pp.288-293
• /
• 2018

There have recently been several studies investigating how to apply a privacy preserving technique to publish data. Differential privacy can protect personal information regardless of an attacker's background knowledge by adding probabilistic noise to the original data. To perform differentially private k-means clustering, the existing algorithm builds a differentially private histogram and performs the k-means clustering. Since it constructs an equi-width histogram without considering the distribution of data, there are many buckets to which noise should be added. We propose a k-means clustering algorithm using a quad-tree that captures the distribution of data by using a small number of buckets. Our experiments show that the proposed algorithm shows better performance than the existing algorithm.

• Journal of Biosystems Engineering
• /
• v.30 no.6 s.113
• /
• pp.366-372
• /
• 2005

The objective of this study was to evaluate the bump crossing and loading stability of a proto-type mini-forwarder under development. The evaluation was performed by computer simulation using a multi-body dynamic analysis program, Recur- Dyn 5.21. The proto-type was modeled and its properties such as mass, mass center, and mass moment of inertia were determined using 3D CAD modeler, Solid Edge 8.0. The $\%$ errors of masses, mass center, mass moment of inertia, and vertical motion of the model were within less than $10\%$ and the model's behavior agreed relatively well with those of the proto-type when traversing over a rectangular bump. Using the validated model, bump crossing of the proto-type was simulated and the loading limit was determined. It was found that effects of the shapes of bump on the bump crossing performance was insignificant within the practical heights of bumps. Stability of bump crossing increased with loading. However, loading of longer logs than 2.7 m made the crossing unstable because the ends of logs contacted ground when traversing over the bump. The maximum loading capacity of the proto-type was estimated to be 7.8 kN of 2.7 m long logs.

• Journal of Korea Spatial Information System Society
• /
• v.11 no.4
• /
• pp.47-55
• /
• 2009

As the wireless internet technology such as mobile phone, WIBRO, HSDPA develops, customized location-based services for traffic, tourism, shopping, and emergency relief has lately attracted attention. For giving customized services. we should consider dynamic characteristics of moving object which continuously change their location. In this paper, we define the context trigger type of moving object and design triggering method for processing context generated by moving object. Also we propose location-based push service platform including context trigger of moving object for supporting location-based information to user. The proposed system gathers moving object stream from the terminal based on MS-assisted or Stand-alone positioning mode of embedded GPS in terminal extract user context by user device agent, and send context information to server.

• Atmosphere
• /
• v.27 no.2
• /
• pp.133-150
• /
• 2017

This study evaluates CMIP5 model performance on rainy season evolution in the East Asian summer monsoon. Historical (1986~2005) simulation is analyzed using ensemble mean of CMIP5 19 models. Simulated rainfall amount is underestimated than the observed and onset and termination of rainy season are earlier in the simulation. Compared with evolution timing, duration of the rainy season is uncertain with large model spread. This area-averaged analysis results mix relative differences among the models. All model show similarity in the underestimated rainfall, but there are quite large difference in dynamic and thermodynamic processes. The model difference is shown in horizontal distribution analysis. BEST and WORST group is selected based on skill score. BEST shows better performance in northward movement of the rain band, summer monsoon domain. Especially, meridional gradient of equivalent potential temperature and low-level circulation for evolving frontal system is quite well captured in BEST. According to RCP8.5, CMIP5 projects earlier onset, delayed termination and longer duration of the rainy season with increasing rainfall amount at the end of 21st century. BEST and WORST shows similar projection for the rainy season evolution timing, meanwhile there are large discrepancy in thermodynamic structure. BEST and WORST in future projection are different in moisture flux, vertical structure of equivalent potential temperature and the subsequent unstable changes in the conditional instability.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.48 no.1
• /
• pp.24-30
• /
• 2011

We have developed a hand-held probe for an ophthalmic OCT system. The hand-held probe for imaging was designed to be compact and portable. The cornea and retinal images were acquired by replacing the objective lens at the front of the probe. To verify the performance of the hand-held OCT probe, we acquired two dimensional OCT image of the rat eye in vivo and reconstructed three dimensional rat eye rendering images. In vivo 3D OCT images were showed distinct structural information in the posterior and anterior chamber with minimal motion artifacts. Thereby, OCT imaging speed is suitable for an dynamic in vivo experiment.

• The Journal of Korean Academy of Prosthodontics
• /
• v.38 no.6
• /
• pp.782-790
• /
• 2000

The mainly used polymeric material for the denture is PMMA because of its cost and easiness to handle. So it was widely used material among dentists for past decades. But the acrylic-based denture materials have several common weak points such as shrinkage after curing and lack of strength. In order to solve these problems, we adapted one of hybrid system using acrylic polymer and vinyloligosilsesquioxane(POSS). POSS, which is a well known expandable monomer during polymerization process, may eventually suppress volumetric shrinkage. And the hybrid system makes it possible for the polymer to be stable in various severe conditions. Eight different kinds of samples were designed and synthesized. Each samples were characterized with dynamic mechanical analyser(DMA) to confirm their thermodynamic properties, fractured to analyze the cross-sectional morphology of the samples. And elongation, flexural and impact tests were also executed to evaluate the mechanical properties of the samples. From the results, hybrid composites had well defined crosslinked network structure compared to the widely used denture materials, and the mechanical strength improved without changing any surface condition as increment with POSS ratio in hybrid system. Fractured morphology showed homogeneous surfaces in spite of mutli component system, therefore we can conclude that the adoption of the POSS brought the reinforcement of the denture resin.