• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.880-884
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• 2014

RT (reverberation time) of outdoor spaces surrounded by multi-storey buildings depends on many designable factors such as the openness, volume and building layouts, etc. This study therefore aims to clarify the influential factors for RT in outdoor spaces surrounded by buildings with complicated topographical conditions. A series of measurements were carried out for 15 outdoor spaces in 6 apartment complexes with different building layouts. An Empirical method considering the openness, averaged ray length and building high is also suggested, to predict RT approximately in the outdoor spaces. The overall results suggest that RT in outdoor spaces of apartment complexes is significantly influenced by source-receiver distance and building layouts.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.03a
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• pp.205-218
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• 2002

Recently, the water pollution of coastal sea area including harbor, bay and inland sea has been very serious and it causes various environmental impacts. In this study, water flow system of Danghang Bay, which has the narrow and long topographical characteristics with the narrow bay mouth and its flow is influenced principally by the tidal current, is investigated experimentally and numerically. In order to understand the tidal system of Danghang Bay, harmonic analysis is performed based on measured tidal range and flow velocity In addition, numerical model for tidal exchange is developed considering conditions of Danghang Ray. Calculated results show good agreement with measurements. Lastly. based on the proposed numerical model, exchange ratio of seawater volume in Danghang Bay is predicted.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.906-909
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• 2000

Conventional caption extraction methods use the difference between frames or color segmentation methods from the whole image. Because these methods depend heavily on heuristics, we should have a priori knowledge of the captions to be extracted. Also they are difficult to implement. In this paper, we propose a method that uses little heuristics and simplified algorithm. We use topographical features of characters to extract the character points and use KMST(Kruskal minimum spanning tree) to extract the candidate regions for captions. Character regions are determined by testing several conditions and verifying those candidate regions. Experimental results show that the candidate region extraction rate is 100%, and the character region extraction rate is 98.2%. And then we can see the results that caption area in complex images is well extracted.

• Macromolecular Research
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• v.11 no.5
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• pp.387-392
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• 2003

The ablation effects of Ar-plasma treatment and alkali-decomposition behavior in NaOH solution of polyethylene terephthalate (PET) film were investigated. The modifications were evaluated by analysis of atomic force microscopy topographical changes, and by the measurement of decomposition yield in conjunction with heats of formation and electron densities of acyl carbon calculated by Parameterization Method 3 method. It has shown that the alkali-decomposition is hampered by plasma treatment and its decomposition yield is closely related with plasma treatment conditions such as exposure time to plasma. Plasma-treated PET films exhibited lower decomposition yield, compared to that of virgin PET. Increasing plasma exposure time contributes positively to decrease the decomposition yield. It has also shown that the topography of PET surface was affected by the base-promoted hydrolysis as well as Ar-plasma treatments. These behaviors are attributed to the decreased nucleophilicity of acyl carbon damaged by the ablation of Ar-plasma.

• Journal of Navigation and Port Research
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• v.26 no.2
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• pp.227-233
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• 2002

Recently, the water pollution of coastal sea area including harbor, bay and inland sea has been very serious and it causes u\\various environmental impacts. In this study, water flow system of Danghnag Bay, which has the narrow and long topographical characteristics with the narrow bay mouth and its flow is influenced principally by the tidal current, is investigated experimentally and numerically. In order to understand the tidal system of Danghang Bay, harmonic analysis is performed based on measured tidal range and flow velocity. In addition, numerical model for tidal exchange is developed considering conditions of Danghang Bay. Calculated results show good agreement with measurement. Lastly, based on the proposed numerical model, exchange ratio of seawater volume in Danghang Bay is predicted.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.5
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• pp.86-92
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• 2002

The benefits of high performance retention systems have been long recognized by the paper maker. The inter-relation between chemical retention and drainage and their effect on paper production efficiency and paper quality is significant. The subject of this paper is a summary of recent studies comparing three microparticle programs made under highly controlled pilot and commercial paper machine conditions. The results presented in this paper suggest that, in addition to improvements in machine operation, the retention, drainage and formation program can have a marked influence on the paper quality. Improvement of the topographical characteristics of the base paper was observed when the microparticle was a colloidal borosilicate inorganic oxide.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.2
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• pp.139-148
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• 2023

Safety standards for long-range artillery ammunition test and training sites follow the US artillery shooting range safety zone standards. Although the South Korean geographical conditions of shooting ranges are different from those of the United States, there is no safety standard reflecting the South Korean topographical characteristics. Probable error associated with the shooting range, trajectory should be considered in establishing the safety standards. In this study, we present the safety standards for the ammunition testing site suitable for the Korean situation, with applying a concept of trajectory and probable error differed by ammunition type, which are currently confirmed by the South Korean Army's artillery shooting.

• Journal of the Korean housing association
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• v.10 no.2
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• pp.213-222
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• 1999

This study, from conditions connected with water in Feng-Shui theory, is to find out their influence of the location and spatial composition of the studied villages, Hawei and Yangdong, and then to offer the result as basic data for the study of the traditional village in the future. The study method is to analyze topography by the map and present state of villages studied, to interprete them on the base of location, spatial composition, and chi, and then to analyze the relevancy of Feng-Shui theory of them. The result of the study are to be following: Houses of Hawei village are situated on the inside of a winding stream of waterway, while those of Yang dong village are located on the outside of a winding stream of waterway. In case of Hawei village, showed the close interrelation between the distribution of present houses and running speed of waterway by positin. Judging from the location, orientation and surroundings of mountains and waterway, topographical composition of Hawei village is Duk su guk, but that of Yang dong village is Juang feng guk. Comparing with Yang dong and Hawei in location and spatial composition, the conditions of waterway as being locational factor, for example, the geomancy of situation, orientation, and phisical phenomena(lenth, width, and depth of waterway in front of village) of waterway, are more importantly considered in Hawei village being situated on even land than in Yang dong located at the foot of the mountain.

• Economic and Environmental Geology
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• v.33 no.2
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• pp.117-128
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• 2000

Regional evaluations of slope stability by the failure criterion and by environmental geological factors were conducted. The failure criterion is the general conditions for plane failure which consider the geometrical conditions between geological discontinuities and topographical slope planes. The factor focused in this condiction is dip and dip direction. Geostatics, named semivariogram was used for establishing structural domains in slope stability evaluation by the failure criterion. The influential range was calculated to 6 km in the case of dip direction of dominant joint set and 7 km in the case of dip of the same dominant joint set. Then applying this failure criterion to the study area produced a slope stability map using the established domains and slopes generated by TIN module of ARC/INFO GIS. This study considered another regional slope stability analysis. 5 failure-driven factors 9the unstable slope map, geology, engineering soil, groundwater, and lineament density) were selected and used as data coverages for regional slope stability evaluation by geoenvironmental factors. These factors were weighted and overlayed in GIS. From the graph of cumulatave area (%) and instability index, finding critical points classified the instability indices. The most unstable slopes are located in the southern area of Mt. Eorae, Dabul-ri, and the eastern area of Junkok-ri in the first area is plane failure. Also, the expected orientations of failure are 59/338 and 86/090 (dip/dip direction).

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.14 no.1
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• pp.89-95
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• 1996

As an attempt to apply GPS technique to aerial photogrammetry, an effort is exerted to replace the ground control points that were necessary in the traditional aerial photogrammetry with the aerial control by measuring the position of the camera exposure. In this study, various situations are simulated to test the conditions that affect the positioning of the points in aerial photogrammetry for the use of GPS data. From the result of the simulations, the necessary conditions and the applicable values to produce a 1:1, 000 topographical map were suggested. In the case of a photo block consists of 104 photos, we found a minimum of six ground control points make acceptable accuracy under the condition of below $10\mu{m}$ image positional error and with the ground observations.