• Honam Mathematical Journal
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• v.41 no.4
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• pp.837-849
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• 2019

Extended elementary cellular automata (EECA) is used to analyze the pattern of genetically modified (GM) gene dispersion to wild genes. Pollination of GM maize mainly occurs by wind. Wind direction was set to two directions left to right and up to down on the cells. Sixteen cases were analyzed to show six kinds of classes of pattern for sixteen iterations. Wind directions were fixed for the simulations to see the effect of the GM maize dispersion by the wind.

• Korean Journal of Remote Sensing
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• v.3 no.2
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• pp.81-87
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• 1987

The study was to analysis the dispersion of the cooling water of Kori atomic power station using thermal infrared data. The dispersion pattern of the cooling water analysis clearly on the LANDSAT TM band 6. It was changed due to tidal current, that is, the cooling water disperses north-eastern direction during the low tide and southweatern direction during the high tide. The relative temperature distribution was mapped through the density slicing method on the images.

• Journal of information and communication convergence engineering
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• v.20 no.4
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• pp.235-241
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• 2022

A dispersion map was proposed to improve the compensation effect of a distorted WDM (wavelength division multiplexed) channel in a dispersion-managed link coupled with optical phase conjugation. The dispersion map is an origin-symmetric structure around the optical phase conjugator in the middle of the transmission path. In addition, the dispersion map has a form in which a constant dispersion accumulation pattern is repeated regularly. Through simulation, we confirmed that the application of the origin-symmetric dispersion map with a repetitively shaped configuration was more effective in compensating for the distorted WDM channel than in the dispersion-managed link with a conventional dispersion map. In addition, we confirmed that the compensation effect could be increased when the cumulative dispersion distribution of the origin-symmetric distribution map had a positive value in the first half section and a negative value in the second half section. Further, we observed that as the number of repeated dispersion accumulation patterns increased, the residual dispersion per span should also be increased.

• Nuclear Engineering and Technology
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• v.56 no.6
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• pp.2039-2049
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• 2024

The radioactive pollutant could migrate to the downstream urban area under the action of atmospheric dispersion due to the turbulent mixing under actual pollution accidents. A scenario in which radioactive contaminants from the upstream (for example, a nearshore nuclear power plant accident) migrates to the downstream urban blocks have been considered in this study. Numerical simulations using computational fluid dynamics (CFD) are then conducted to investigate the effects of the urban morphology (building packing density and layout) on the atmospheric dispersion of radioactive pollutants in this scenario. The building packing density and structure can significantly affect urban areas' mean flow pattern and the turbulent kinetic energy (TKE). The flow pattern and the TKE distribution influence the radioactive pollution dispersion. It is found that the radioactive pollution at the urban canyons is significantly affected by the vertical transport at the canyon. A comparison of the distributions of radioactive and traditional non-radioactive pollutants is also provided.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.12
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• pp.1325-1333
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• 2014

The dispersion pattern of a near miss neutralizer has a great effect on the disablement of a threatening projectile. This study numerically investigated the dispersion pattern of cylindrical tungsten impactors by an explosion in the near miss neutralizer. The mass and shape of the explosive were considered as influencing factors on the dispersion pattern. The explosives were set using two shape models: a parallel shape with the same upper and lower thicknesses and a tapered shape with different upper and lower thicknesses. In the simulation results, the dispersed impactors formed a ring-shaped pattern on a two-dimensional plane in an arbitrary space. In addition, the fire net area increased with the explosive mass when the explosive shapes were identical. In particular, the tapered shape explosive formed a larger fire net area than the parallel shape explosive. Based on the analysis of the fire net area along with the dispersion density, both the explosive mass and shape representing the physical characteristics should be considered for controlling the dispersion pattern of impactors in a near miss neutralizer.

• Journal of information and communication convergence engineering
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• v.12 no.2
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• pp.75-82
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• 2014

Dispersion management (DM), optical phase conjugation (OPC), and the combination of DM and OPC are promising techniques to compensate for optical signal distortion due to group velocity dispersion and nonlinear Kerr effects. The system performance improvement in DM links combined with OPC has been reported; however, the fixed residual dispersion per span (RDPS) usually used in these links restricts the flexibility of link configuration. Thus, in this paper, a flexible optical link configuration with artificially distributed single-mode fiber (SMF) lengths and RDPS in the combination of DM and OPC is proposed. Simulation results show that the best artificial distribution pattern is the gradually descending distribution of SMF lengths and the gradually ascending distribution of RDPS, as the number of fiber spans is increased, regardless of the average RDPS, the optimal net residual dispersion, and the dispersion coefficient of the dispersion compensating fiber.

• Journal of information and communication convergence engineering
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• v.15 no.4
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• pp.205-211
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• 2017

Combining dispersion-managed optical links with midway optical phase conjugation (OPC) is a possible method of compensating for optical signal distortion due to group velocity dispersion and nonlinear Kerr effects. Although an improvement in the performance of these optical links has been reported, the fixed residual dispersion per span (RDPS) that is typically used restricts the flexibility of link configurations. Thus, in this paper, a flexible dispersion-managed link configuration, comprising artificial distributions of linearly/nonlinearly incremented RDPS, is proposed. Simulations show that a descending distribution of RDPS before the midway OPC, and an ascending distribution of RDPS after the midway OPC, gives the best artificial distribution pattern as the number of fiber spans is increased, regardless of the RDPS incrementation method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.625-626
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• 2015

The optimal distribution pattern for the compensation for the distorted WDM signals due to the group velocity dispersion (GVD) and the nonlinear Kerr effects is induced in $80km{\times}50spans$ optical link with an artificial distributions of single mode fiber (SMF) lengths and residual dispersion per span (RDPS).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.655-658
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• 2012

Optimal net residual dispersion (NRD) and distribution pattern of (SMF) length and residual dispersion per span (RDPS) in optical transmission links with artificial distribution of SMF length and RDPS required to flexibly design of optical links in dispersion management (DM) technique for compensating the distorted 960 Gbps optical signals due to interaction of group velocoty dispersion (GVD) and optical nonlinear effects are induced.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.5
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• pp.59-76
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• 2009

This study was conducted to supply basic data for restoration and management of forests in Civilian Control Zone, with surveying naturalized plants around abandoned military camps. The total study sites are 72 abandoned military camps, from Gosung in east region to Paju in west region of Civilian Control Zone. The naturalized index of total area is 12.6%, and naturalized index of east and middle regions are 12.1% and 8.4%. But its index of west region is 15.9%. These results are due to geographical characteristics. The east and middle regions are in steep mountainous districts, and so but west region is flat district, and so naturalized plants was imported by only army. But west region is in flat districts, and so imported method of naturalized plants is very various. The main naturalized plants are Ambrosia trifida and Ambrosia artemisiifolia var. elatior in Civilian Control Zone. The main dispersion pattern of naturalized plants are gravity dispersion pattern ($D_4$) and wind and water dispersion pattern ($D_1$). The all naturalized plants are photophilic plants in survey sites. And so, if abandoned military camps are recovered to forests, the naturalized plants are disappeared because of the change of sunlight condition. So it is necessary to manage and recover forests, even if that area is Civilian Control Zone.