• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2300-2305
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• 2009

Recently, Telecommunication companies have introduced a new network architecture that assigns network resources consistent and protects their systems more secure. Now, they provide multimedia services through various types of access networks. In this study, I'd like to introduce IP address assignment method based on the Dynamic Host Configuration Protocol (DHCP) and find out how success or failure of Ip address assignment will be taken place according to the booting order of xDSL modem, AP and PC.

• Journal of Korea Multimedia Society
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• v.11 no.12
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• pp.1722-1729
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• 2008

This paper describes the contents about the efficient routing technique for improvement of transmission in Wireless Sensor Networks. Existing flat-based routing protocols have several problems like data overlap and implosion. Gossiping Algorithm in WSN is able to reduce the overhead and transmit packets through already set up the path but it takes place the data delivery and problem of worst-case. In this paper, we try to solve two problems that are data delivery and worst-case by selecting neighbor nodes using RSSI and number of linkage. The proposed model is available to real-mote and we confirmed the improvement of the performance against existing models.

• Bulletin of the Korean Chemical Society
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• v.20 no.10
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• pp.1209-1212
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• 1999

The entropies and chemical potentials of hard-sphere solutes solvated in hard-sphere solids were calculated by Monte Carlo method using the radial free-space distribution function. This method is based on calculating the entropy by comparing the free volume of a molecule with that of an ideal gas, and is applicable even when the size of solute is very large and the solvent is a solid. When the diameter of hard-sphere solute is small the solute molecule behaves as like as a fluid in solid structures, but when the diameter of solute becomes large, a fluid-to-solid phase transition takes place. The fluid-to-solid phase transition occurs at the region of the smaller size of solute with the more increase of solvent density. The least square fit values of analytical form of the radial free-space distribution functions of solute molecules are presented for future uses.

• Journal of Plant Biology
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• v.27 no.2
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• pp.51-60
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• 1984

Jisimdo is an island where evergreen broadleaved forests are well preserved. Soil environments and forest structures of Jisimdo were investigated, and an actual vegetation map and profile diagrams were drawn out. The natural vegetation of Jisimdo was divided into two stand units, one was evergreen broadleaved forest and the other was Pinus thunbergii forest. 26 species were identified as evergreen broadoeaved trees, and among them, Camellia japonica was the dominont of the tree layer of evergreen broadleaved forest. Profile diagram shows that Camellia japonica, with average height of 7∼8m, formed lower tree layer, and laurels like Cinnamomum japonicum, Machilus thunbergii, and Neolitsea sericea formed upper tree layer. In Pinus thunbergii forest, plants of shrub and herb layers were abundant because of much light penetrated into the forest floor, and these layers were largely composed of evergreen broadleaved trees. This fact shows the possibility of succession from Pinus thunbergii forest into evergreen broadleaved forest. Jisimdo is geographically adjacent to Jangseungpo and Okpo, and this increases the economic value of Jisimdo as a place of public resort. It will be necessary from being destroyed by land development and human interferences.

• The Journal of Korea Robotics Society
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• v.16 no.3
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• pp.245-249
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• 2021

In this paper, we present novel simulation contents for drone racing and autonomous flight of drone. With Depth camera and SLAM, we conducted mapping 3 dimensional environment through RTAB-map. The 3 dimensional map is represented by point cloud data. After that we recovered this data in Unreal Engine. This recovered raw data reflects real data that includes noise and outlier. Also we built drone racing contents like gate and obstacles for evaluating drone flight in Unreal Engine. Then we implemented both HITL and SITL by using AirSim which offers flight controller and ROS api. Finally we show autonomous flight of drone with ROS and AirSim. Drone can fly in real place and sensor property so drone experiences real flight even in the simulation world. Our simulation framework increases practicality than other common simulation that ignore real environment and sensor.

• Journal of Korean Philosophical Society
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• v.131
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• pp.105-130
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• 2014

In this paper I would like to examine critically technology in this age. In the first place, I discuss various dangerous aspects of contemporary technology. In the second and third section, I do research in Heidegger's and Ellul's philosophy of technique and appreciate them. Finally, as the result of it, I suppose the alternative perspective in social structure. This is my main intent.

• International journal of advanced smart convergence
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• v.10 no.2
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• pp.45-52
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• 2021

The surveillance camera market has developed and plays an important role in the field of video surveillance. However, in recent years, the identification of areas requiring surveillance has been limited by reflective light in the surveillance camera market. Cameras using polarization filters are being developed to reduce reflective light and facilitate identification. Programs are required to automatically adjust polarization filters. In this paper, we proposed an optimal angle extraction method from surveillance cameras using polarization filters through histogram analysis. First of all, transformed to grayscale to analyze the specifications of frames in multiple polarized angle images, reducing computational throughput. Then we generated and analyzed a histogram of the corresponding frame to extract the angle when the highlights are the fewest. Experiments with 0˚ and 90˚ showed high performance in extracting optimal angles. At this point, it is hoped this technology would be used for surveillance cameras in place like beach with a lot of reflective light.

• Bulletin of the Korean Chemical Society
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• v.16 no.3
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• pp.252-256
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• 1995

Semiempirical MO calculations using the PM3 method are performed on the reactions of acetate esters with substituted phenolate anions. The mechanistic change from rate-limiting formation to breakdown of the anionic intermediate is shown to occur in the gas-phase, especially for meta-nitrophenyl acetate. However the mechanistic change-over takes place at a lower basicity ($pK_0$) of the anion nucleophile than found for the corresponding formate. This lowering of $pK_0$ has been ascribed to the electron donating effect of the methyl group in the acetate. For the reactions involving rate-limiting breakdown of the intermediate, the large Bronsted coefficients, ${\beta}_X({\beta}_{nuc})$, are expected in general, but the magnitude increases to a larger value and the pK0 is lowered accordingly, when an electron-donating nonleaving group, like $CH_3$, is present. This type of nonleaving group effect provides a necessary condition for the carbonyl addition-elimination mechanism with rate-limiting breakdown of the intermediate.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.12-16
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• 2021

Soccer is one of the popular sports globally, and South Korea is no exception; the professional domestic soccer tournament has been held in South Korea since 1983. The national soccer team in South Korea has shown outstanding performances, hosting the 2002 World Cup and achieving a bronze medal at the London 2012 Olympic Games and second place at the 2019 U-20 World Cup. In addition, one of the South Korean soccer players, Heung-min Son, has played a remarkable role in the English Premier League. Like other global soccer clubs, South Korean domestic soccer clubs create and manage their own YouTube channel to interact with fans and keep them updated. In this study, we explore how and why Seoul E-Land Football Club (SEFC) utilizes its YouTube channel. SEFC is distinctive in that they are playing at the second division, their home ground is based in Seoul, and they are sponsored by a company run on Christian values. We analyze one of the soccer club's YouTube channels multi-dimensionally and discover the roles of YouTube.

• Mycobiology
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• v.50 no.3
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• pp.172-180
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• 2022

The new genus and species, Jejulea byssolomoides, is described from Jeju Island, Korea. This lichen is characterized by saxicolous, crustose, pale greenish-gray, partly finely filamentous, matt, smooth thallus, prominent convex brown to dark brown ascomata with a concolorous margin constricted at the dark brown base, 300-800 ㎛ diameter, 200-250 ㎛ high, without a distinct proper margin, adhering to the substratum ending in a minute byssoid white external part of cylindrical cells, fusiform 3-5 septate ascospores (17-23 × 4-5 ㎛). Phylogenetic analyses using ITS and mtSSU sequences place Jejulea in the Pilocarpaceae (Lecanorales). The new taxon is closely related to Byssoloma, a cosmopolitan group of foliicolous lichens, which is most diverse in the tropics. Like Byssoloma, Jejulea also forms a byssoid apothecial margin.