• Journal of KIISE:Information Networking
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• v.33 no.3
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• pp.193-200
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• 2006

The security feature is essential in wireless sensor network such as intrusion detection or obstacle observation. Sensor nodes must have shared secret between nodes to support security such as privacy. Many methods which provide key pre-distribution need too many keys or support poor security. To solve this problem, probabilistic key pre-distribution is proposed. This method needs a few keys and use probabilistic method to share keys. However, this method does not guarantee key sharing between nodes, and neighbor nodes nay not communicate each other. It leads to waste of network resource such as inefficient routing, extra routing protocol. In this paper, we propose new key distribution method using quorum system which needs a few keys and guarantee key sharing between nodes. We also propose extension of the method which needs fewer keys and guarantee key sharing when node deployment knowledge is well known.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.3
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• pp.57-69
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• 2016

In this study, we analyzed the extreme rainfall distribution scenarios based on probable rainfall calculation and applying various time distribution models over the landslide high risk zones in urban areas. We used observed rainfall data form total 71 ASOS (Automated Synoptic Observing System) station and AWS (Automatic Weather Station) in KMA (Korea Meteorological Administration), and we analyzed the linear trends for 1-hr and 24-hr annual maximum rainfall series using simple linear regression method, which are identified their increasing trends with slopes of 0.035 and 0.660 during 1961-2014, respectively. The Gumbel distribution was applied to obtain the return period and probability precipitation for each duration. The IDF (Intensity-Duration-Frequency) curves for landslide high risk zones were derived by applying integrated probability precipitation intensity equation. Results from IDF analysis indicate that the probability precipitation varies from 31.4~38.3 % for 1 hr duration, and 33.0~47.9 % for 24 hr duration. It also showed different results for each area. The $Huff-4^{th}$ Quartile method as well as Mononobe distribution were selected as the rainfall distribution scenarios of landslide high risk zones. The results of this study can be used to provide boundary conditions for slope collapse analysis, to analyze sediment disaster risk, and to use as input data for risk prediction of debris flow.

• Journal of Environmental Impact Assessment
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• v.24 no.3
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• pp.260-277
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• 2015

The object of this study was the climate change sensitivity assessment of Korean Fir and Khinghan Fir as a representative subalpine plant in South Korea. Using species distribution models, we predicted the probability of current and future species distribution. According to this study, potential distribution that have been predicted based on the threshold (MTSS) is, Khinghan Fir was higher loss rate than Korean Fir. And in the climate change sensitivity assessment using the scalar sensitivity weight ($W_{is}$), $W_{is}$ of Korean Fir was higher relatively than the sensitivity of Khinghan Fir. When using the species distribution models as shown in this study may vary depending on the probability of presence data and spatial variables. Therefore should be prior decision studies on the ecological environment of the study species. Based on this study, if it is domestic applicable climate change sensitivity assessment method is developed. it would be important decision-making to climate change and biological diversity of adaptation policy.

• The Journal of Fisheries Business Administration
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• v.37 no.2 s.71
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• pp.61-83
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• 2006

In Side of Supply and Demand of Fisheries Products, The Aquacultural Industry stayed in subsidized situation for the whole fishery industry of korea when it's dawned. But now a day, the Aquacultural Industry has been developed to unique industry itself, and it could be said the Hoe - korean style Sashimi or Sushi culture of korea can't exist without its aquacultural industry. So it could be said that the Aquacultural industry is not only a part of the fishery industry but also inevitable unique industry. The main objective of this paper is to analysis the present situation for production of Flatfish, distribution of Flatfish, and consumption structure of Flatfish. Especially, the production for aquacultural Flatfish in 2005 has been raised over 38 times against the production in 1990, and it takes the status as the major fish which leads the domestic aquacultural industry compare with others. The distribution of Flatfish can be divided to the domestic and export mainly. In field of its domestic distribution, Flatfish is the major item with Rockfish, and the deal of its over 90% happens in Similarity Fishery Wholesale Markets such as In-chon, Ha-nam, and Bu-san Fishery Wholesale Market not in the common distribution process of the fishery products. At present, the exporting of Flatfish take 13.9% among the whole Aquacultural Industry of korea, and Flatfish mainly export to Japan. Also, through the development of chinese economy, Hoe consumption culture is expanded gradually. And the future of exporting Flatfish is very bright because of developing of the U.S. market. The brief introduction of the consumption style of live fish is as belows. According to the research, generally the most of korean consumers prefer individual item as their food to combination style in korean Hoe consumption culture and the favorite item of korean consumers are Flatfish and Rockfish.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.7
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• pp.439-445
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• 2015

We established the emulsion method using membrane filter with precise control of LC droplet distribution in PDLC. PDLC cells with various LC droplet size distributions such as single droplet sizes of $1.0{\mu}m$, $1.9{\mu}m$ and $3.5{\mu}m$, the mixture of two different LC droplet sizes and the mixture of three different LC droplet sizes were fabricated and the electro-optical properties of the emulsion type PDLC cells with various droplet size distribution were investigated. In the appropriate droplet size range, the PDLCs with the single droplet sizes distributions have good electro optical properties than those with the mixture of three different LC droplet sizes. In addition, the PDLC cells with the mixture of two different LC droplet sizes have the better electro optical properties than those with single droplet sizes distribution. The PDLC cell with dual droplet size distribution of $1.0+1.9{\mu}m$ shown the best electro optical properties than the PDLC cells with other size distributions. This method enabled us to find the proper LC droplet size distribution for achieving both high transmittance and contrast ratio.

• Radiation Oncology Journal
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• v.1 no.1
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• pp.11-19
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• 1983

Interaction between high energyelectrons and matters had many complex reactions and the high energy electrons lost their energies with collision and scattering, therefore, electrons distribution in matters was shown as various situation by scattering, exciting and ionizing with moleculars. We experimentally studies with 13 MeV Linear Accelerator and thermoluminescence dosimeter using aluminium and Teflon, etc., and measured energy loss of electrons, electron range, electron scattering and dose distribution in matter. We compared the results with theoretical formular, between 4-qw MeV, the energy loss of electrons was decreased by 2 MeV per $1g/cm^2$ but under 1MeV it was rapidly decreased. Electron range in matter reached to $0.5/cm^2$ per 1MeV of incident energy at 6-12MeV. The dose distribution in matter was increased slightly to some depth by total distribution i.e., the combined intensity of primary and secondary radiant and it was rapidly decreased near the maximum range of electrons. Energy loss of electrons and electron range measured by experiment were coincided with theoretical equations of L. Landau and Feather under 5 and 3% errors respectively. The dose distribution of electrons in matter was similar to L.V. Spencer formular, however, we had found that it was quite different in accordance with the field size and that new formular of dose distribution was induced as empirical function contained experimental factors according to field size.

• KIEAE Journal
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• v.15 no.6
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• pp.19-26
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• 2015

Purpose: The repair would require to conserve and improve the building function and performance since built. Each household is responsible for maintaining the public facilities and paying the required cost. Therefore, it needs to get the tool or method to forecast the required cost in the future. Before the repair cost is provided, it needs to catch the repair cost distribution and provide the unit cost for the repair cycle. In this study, it aimed at providing the repair cost unit and analyzing the repair cost distribution in a roof proofing work, elevator work and building painting, which are divided into a fully work and partly change. Results of this study are shown that first, the average repair cost for roof proofing work is provided with $166.59{\times}10^3won/household$ and $1.59{\times}10^3won/m^2$ of a full change, $33.22{\times}10^3won/household$ and $0.33{\times}10^3won/m^2$ for a partly work. In addition, elevator work is $557.45{\times}10^3won/household$ and $5.38{\times}10^3won/m^2$ for a full change, $32.92{\times}10^3won/household$ and $0.56{\times}10^3won/m^2$ for a partly repair. Painting has a $304.48{\times}10^3won/household$ and $2.94{\times}10^3won/m^2$. Second, the distribution pattern of repair unit cost has a weibull-typed distribution which has a long tail to the right.

• Journal of the Korean Geotechnical Society
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• v.32 no.1
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• pp.35-43
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• 2016

The time distribution of rainfall is one of the most important considerations for evaluating soil slope stability. In order to study the rainfall-induced slope failure, the rainfall pattern has generally been assumed as uniform rainfall intensity for rainfall duration. However, it should be noted that the time distribution of the design rainfall method has a significant effect on the soil slope instability. The study implemented Mononobe, Huff, and uniform method as three types of time distribution method of the design rainfall to estimate the factor of safety of soil slopes by rainfall duration. As a result, the difference of soil suction and unsaturated hydraulic properties in a soil by rainfall pattern was found through the application of an appropriate time distribution method to numerical simulation for rainfall-induced slope stability.

• Journal of the Korean Society for Railway
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• v.11 no.2
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• pp.151-157
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• 2008

The DPF temperature distribution which has a great effect on regenerating the ceramic filter effectively was measured at 30 locations using K-type thermocouples. Five partitioned electric heaters were used for heating the ceramic filter and they are switched ON/OFF in order. Also, the temperature distribution in the ceramic filter was measured with varying the electrical power supply to the heaters and the mass flow rate of the air supply from a blower. The uniform distribution of the air flow velocity at the inlet of the DPF make that of the temperature in the ceramic filter. The difference in heating ability between the partitioned heaters had a great effect on the temperature distribution in the ceramic filter.

• Journal of Astronomy and Space Sciences
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• v.27 no.1
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• pp.1-10
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• 2010

The distance distribution in our planetary system has been a controversial matter. Two kinds of important issues on Titius-Bode's relation have been discussed up to now: one is if there is a simple mathematical relation between distances of natural bodies orbiting a central body, and the other is if there is any physical basis for such a relation. We have examined, by applying it to exo-planetary systems, whether Titius-Bode's relation is exclusively applicable to our solar system. We study, with the $X^2$ test, the distribution of period ratios of two planets in multiple planet systems by comparing it with that derived from not only Titius-Bode's relation but also other forms of it. The $X^2$ value between the distribution of the orbital period derived from Titius-Bode's relation and that observed in our Solar system is 12.28 (dof=18) with high probability, i.e., 83.3 %. The value of $X^2$ and probability resulted from Titius-Bode's relation and observed exo-planetary systems are 21.38 (dof=26) and 72.2 %, respectively. Modified forms we adopted seem also to agree with the planetary system as favorably as Titius-Bode's relation does. As a result, one cannot rule out the possibility that the distribution of the ratio of orbiting periods in multiple planet systems is consistent with that derived from Titius-Bode's relation. Having speculated Titius-Bode's relation could be valid in exo-planetary systems, we tentatively conclude it is unlikely that Titius-Bode's relation explains the distance distribution in our planetary system due to chance. Finally, we point out implications of our finding.