• Journal of the Korean Geographical Society
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• v.48 no.4
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• pp.545-556
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• 2013

This study sets up nodal regions for shopping and leisure with 424 district units located in Seoul and examines the characteristics of the vertical structure and the regional system. According to the higher-order analysis result, the trip for leisure forms a greater part, and about each of the nodal regions of the first stratum, major spots for origin and destination are located in the center, and those spots are connected to adjacent district units located nearby. As the factor's eigenvalue is bigger, the spatial range gets greater, too, and is located in outsides. And in the third or higher strata, either linkage between Gangnam and Gangbuk or leapfrogging linkage according to the bipolar factors is distinctive. Linkage between nodal regions centering around Jongro-gu, Jung-gu, Gangnam-gu, or Yeoungdeungpo-gu is not distinct, and in particular, the nodal regions of Jongro Geumcheon are maintained as the upper strata being independent from other nodal regions from the second or higher strata.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11C
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• pp.1044-1051
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• 2006

System level diagnosis algorithms use the properties of t-diagnosable system where the maximum number of the faults does not exceed 1. The existing diagnosis algorithms have limit when dealing with large fault sets in large multiprocessor systems. Somani and Peleg proposed t/k-diagnosable system to diagnose more faults than t by allowing upper bounded few number of units to be diagnosed incorrectly. In this paper, we propose adaptive hypercube diagnosis algorithm using t/k-diagnosable system. When the number of faults exceeds t, we allow k faults to be diagnosed incorrectly. Simulation shows that the performance of the proposed algorithm is better than Feng's HADA algorithm. We propose new algorithm to reduce test rounds by analyzing the syndrome of RGC-ring obtained in the first step of HADA/IHADA method. The proposed algorithm also gives similar performance compared to HYP-DIAG algorithm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.424-424
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• 2008

Dye-sensitized Solar Cell (DSC) is a new type of solar cell by using photocatalytic properties of $TiO_2$. The electric potential distribution in DSCs has played a major role in the operation of such cells. Models based on a built-in electric field which sets the upper limit for the open circuit voltage(Voc) and/or the possibility of a Schottky barrier at the interface between the mesoporous wide band gap semiconductor and the transparent conducting substrate have been presented. $TiO_2$ thin films were deposited on the FTO substrate by Nd:YAG Pulsed Laser Deposition(PLD) at room temperature and post-deposition annealing at $500^{\circ}C$ in flowing $O_2$ atmosphere for 1 hour. The structural properties of $TiO_2$ thin films have investigated by X-ray diffraction(XRD) and atomic force microscope(AFM). Thickness of $TiO_2$ thin films were controlled deference deposition time and measurement by scanning electron microscope(SEM). Then we manufactured a DSC unit cells and I-V and efficiency were tested using solar simulator.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.7
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• pp.3747-3765
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• 2017

Existing authentication mechanisms in cellular mobile communication networks are realized in the upper layer by employing cryptographic techniques. Authentication data are broadcasted over the air in plaintext, enabling attackers to completely eavesdrop on the authentication and get some information about the shared secret key between legitimate nodes. Therefore, reusing the same secret key to authenticate several times results in the secret key's information leakage and high attacking rate. In this paper, we consider the most representative authentication mechanism, Authentication and Key Agreement (AKA), in cellular communication networks and propose an enhanced AKA scheme based on Physical Layer Authentication (AKA-PLA). Authentication responses generated by AKA are no longer transmitted in plaintext but masked by wireless channel characteristics, which are not available to adversaries, to generate physical layer authentication responses by a fault-tolerant hash method. The authenticator sets the threshold according to the authentication requirement and channel condition, further verifies the identity of the requester based on the matching result of the physical layer authentication responses. The performance analyses show that the proposed scheme can achieve lower false alarm rate and missing rate, which are a pair of contradictions, than traditional AKA. Besides, it is well compatible with AKA.

• Research in Plant Disease
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• v.24 no.1
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• pp.81-85
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• 2018

Chinese artichoke (Stachys sieboldii Miq.) belongs to herbaceous perennial plants of Labiatea and is cultivated as edible and medicinal crops in China, Japan and Korea. A Chinese artichoke plant showing virus-like symptoms was collected in Chungju, Korea. Plant sap of the sample was inoculated in Nicotiana tabacum cv. Xanthi-nc, Chenopodium quinoa and Chenopodium amaranticolor. Necrotic local lesions were observed in the inoculated leaves of N. tabacum cv. Xanthi-nc and C. amaranticolor, C. quinoa with systemic chlorotic spots and mosaic symptoms on the upper leaves. The disease reactions on indicator plants suggested that the collected Chinese artichoke sample was mixed-infected with different viruses. We detected three viruses by RT-PCR analysis using genus- and species-specific primer sets for Alfalfa mosaic virus (AMV), Cucumber mosaic virus (CMV) and Tobacco mosaic virus (TMV). This study is the first report of a mixed infection of three viruses in Chinese artichoke in Korea.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.309-312
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• 2008

The advent of high resolution products of surface wind and temperature derived by satellite data has permitted us to investigate ocean and atmosphere interaction studies in detail. Especially the Kuroshio extension region of the western North Pacific is considered to be a key area for such studies. We have constructed gridded products of surface wind/wind stress over the world ocean using satellite scatterometer (Qscat/SeaWinds), available as the Japanese Ocean Flux data sets with Use of Remote sensing Observation (J-OFURO). Using new data based on improved algorithm which have been recently delivered, we are reconstructing gridded product with higher spatial resolution. Intercomparison of this product with the previous one reveals that there are some discrepancies between them in short-period and high wind-speed ranges especially in the westerly wind region. The products are validated by not only comparisons with in-situ measurement data by mooring buoys such as TAO/TRITON in the tropical Pacific and the Kuroshio Extension Observation (KEO) buoys, but also intercomparison with numerical weather prediction model (NWPM) products (the NRA-1 and 2). Our products have much smaller mean difference in the study areas than the NWPM ones, meaning higher reliability compared with the NWPM products. Using the high resolution products together with sea surface temperature (SST) data, we examine a new type of relationship between the lower atmosphere and upper ocean in the Kuroshio Extension region. It is suggested that the spatial relation between the wind speed and SST depends upon, more or less, the surrounding oceanic condition.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.2
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• pp.191-203
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• 1992

This paper dealt with the statistical values including mean, standard deviation, variance and coefficient of variation for 14 soil parameters available of Lade's double work-hardening model in order to predict the behaviour of granular soil. 27 sets of all 14 parameters for Baekma river sand were determined by regression using raw data acquired from 12 isotropic compression tests and 9 triaxial compression tests with the variation of confining pressure of 1, 2, and $4kg/cm^2$ respectively 3 times performed during this study. The characteristics of each parameters were investigated. By determining the range of the upper and lower bound dependent on the increase and decrease of the standard deviation from mean value of parameters, sensitivity of all the parameters was scrutinized, by which in turn the influence of experimental error generated inevitably during tests on the determination of soil parameters was also examined.

• Proceedings of the Mineralogical Society of Korea Conference
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• 2000.05a
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• pp.19-19
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• 2000

;Ultramafic xenoliths found in alkali basalts from Jeju-do, Korea are mostly spinel Iherzolites composed of olivine, orthopyroxene, clinopyroxene and spinel. A subordinate amount of spinel harzburgites and pyroxenites are also found. Temperatures for these xenoliths were estimated from the compositions of coexisting pyroxenes (Wood '||'&'||' Banno 1973; Wells 1977; Bertrand '||'&'||' Mercier 1985; Brey '||'&'||' Kohler 1990), the AI-solubility in orthopyroxene coexisting with olivine and spinel (Sachtleben '||'&'||' Seck 1981; Webb '||'&'||' Wood 1986), and from Fe/Mg partitioning between olivine and spinel (Ballhaus et al. 1991). Temperature estimates from the thermometers by Wells (1977) and Brey and Kohler (1990) are compatible. Average equilibrium temperatures by these two methods for spinel peridotites range from 890 to 1030$^{\circ}$C. Pressures for spinel peridotites were estimated from the geobarometer by Kohler and Brey (1991) derived from the equilibrium Ca content of olivine coexisting with clinopyroxene, and fall within the range of 12.9 to 26.3 kbar. The combination of the thermometer by Brey and Kohler (1990) and the geobarometer by Kohler and Brey (1991) yields P- T estimates for Jeju-do spinel peridotites that fall in experimentally determined spinel lherzolite field in CFMASCr system (O'Neill 1981). These P-T data sets have been used to construct the Quaternary Jeju-do geotherm, which is significantly different from the conventional conductive geotherm. The xenolith-derived geotherm has a higher T gradient at low P (13 kbar) than at high P, which may be due to perturbation of the conductive heat flow by magma underplating or overplating at the crust-mantle boundary. Temperature estimates and statistics on the xenoliths indicate that the crust/mantle boundary in Jeju-do lies at about 11 kbar (~39 km). Spinellherzolite is inferred as a main constituent rock of the uppermost lithospheric mantle beneath Jeju-do. Pyroxenites were intercalated in peridotites in similar depth and temperature as re-equilibrated veins or lens.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.6
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• pp.48-63
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• 2008

This research is to apply suitable natural ecosystem evaluation criteria in order to develop the ecosystem conservation, restoration and ways to build substitute habitats as a compensation plan for damaged soundly natural ecosystems in small-scale projects such as resource recovery facility, filtration, etc. The environmental ecology evaluation i.e. generally based on their actual vegetation, community structure, wildlife, water system survey were measured the primary plans for reflecting unique natural environment level of site. As a result, it is necessary to conserve the land in fallow type of wetland, good conservative condition of deciduous forest, wetlanded watercourse for amphibia and reptiles crossing. However, the plan of filtration plant was destroyed wetland(sound ecosystem), natural forest, asian toad spawning area. According to the result of it schemed to build alternative wetland and spawning area, plan to healthy ecosystem and surface soil transplantation as compensation plan. The alternative wetland and spawning area are not only created a various water levels like depth of water is $0{\sim}30cm,\;30{\sim}60cm$, more than 1.5m but also it leads to asian toad spawning and wildlife inhabitant. Moreover, the ecosystem and surface soil transplantation be applied to use the Quercus acutissima forest resources(114 upper trees, 71 canopy trees, 401 shrubs) and surface soil$(5,072m^3)$ in ecology creation sets.

• Journal of the Korean Association of Geographic Information Studies
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• v.13 no.3
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• pp.1-13
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• 2010

The aim of this study is to analyze gold-silver mineral potential in the Taebaeksan mineralized district, Korea using a Geographic Information System(GIS) and an artificial neural network(ANN) model. A spatial database considering Au and Ag deposit, geology, fault structure and geochemical data of As, Cu, Mo, Ni, Pb and Zn was constructed for the study area using the GIS. The 46 Au and Ag mineral deposits were randomly divided into a training set to analyze mineral potential using ANN and a test set to verify mineral potential map. In the ANN model, training sets for areas with mineral deposits and without them were selected randomly from the lower 10% areas of the mineral potential index derived from existing mineral deposits using likelihood ratio. To support the reliability of the Au-Ag mineral potential map, some of rock samples were selected in the upper 5% areas of the mineral potential index without known deposits and analyzed for Au, Ag, As, Cu, Pb and Zn. As the result, No. 4 of sample exhibited more enrichments of all elements than the others.