• Journal of Korean Society of Transportation
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• v.12 no.3
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• pp.49-64
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• 1994

The development of a mathematical modular framework based on Petri Network theory to model a traffic network is the subject of this paper. Traffic intersections are the primitive elements of a transportation network and are characterized as event driven and asynchronous systems. Petri network have been utilized to model these discrete event systems; further analysis of their structure can reveal information relevant to the concurrency, parallelism, synchronization, and deadlock avoidance issuse. The Petri-net based model of a generic traffic junction is presented. These modular networks are effective in synchronizing their components and can be used for modeling purposes of an asynchronous large scale transportation system. The derived model is suitable for simulations on a multiprocessor computer since its program execution safety is secured. The software pseudocode for simulating a transportation network model on a multiprocessor system is presented.

• Geomechanics and Engineering
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• v.30 no.4
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• pp.353-362
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• 2022

The seismic failure-prone region in Istanbul has been examined in terms of the segmented pipelines. Although some researchers have suggested that this territory should be left as a green land, many people continue to live in this area. This region is about 9-10 km away from the North Anatolian Fault Line. This fault zone is an active right-lateral strike-slip fault line in Turkey and an earthquake with a magnitude of 7.0-7.5 is expected in the Marmara Sea. Therefore, superstructures and infrastructures are under both land sliding risks and seismic risks in this area. Because there are not any pipeline-fault line intersection points in the region, in this study, it has been focused on the behaviors of the segmented (sewage or stormwater) pipelines subject to earthquake-induced permanent ground deformation and seismic wave propagation. Based on the elastic beam theory some necessary analyses have been carried out and obtained results of this approximation have been examined.

• Journal of Korea Multimedia Society
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• v.7 no.12
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• pp.1671-1679
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• 2004

This study has proposed visual-feature extraction methods for each band in wavelet domain with both spatial frequency features and multi resolution features. In addition, it has brought forward similarity measurement method using fuzzy theory and new color feature expression method taking advantage of the frequency of the same color after color quantization for reducing quantization error, a disadvantage of the existing color histogram intersection method. Experiments are performed on a database containing 1,000 color images. The proposed method gives better performance than the conventional method in both objective and subjective performance evaluation.

• Communications of the Korean Mathematical Society
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• v.39 no.3
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• pp.563-574
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• 2024

Given a sequence of point blow-ups of smooth n-dimensional projective varieties Z_i defined over an algebraically closed field $k,\,Z_s\,{\overset{{\pi}_s}{\longrightarrow}}\,Z_{s-1}\,{\overset{{\pi}_{s-1}}{\longrightarrow}}\,{\cdots}\,{\overset{{\pi}_2}{\longrightarrow}}\,Z_1\,{\overset{{\pi}_1}{\longrightarrow}}\,Z_0$, with Z₀ ≅ ℙⁿ, we give two presentations of the Chow ring A^•(Z_s) of its sky. The first one uses the classes of the total transforms of the exceptional components as generators and the second one uses the classes of the strict transforms ones. We prove that the skies of two sequences of point blow-ups of the same length have isomorphic Chow rings. Finally we give a characterization of the final divisors of a sequence of point blow-ups in terms of some relations defined over the Chow group of zero-cycles A₀(Z_s) of its sky.

• Journal of Korean Society of Transportation
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• v.28 no.6
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• pp.109-120
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• 2010

This study aims to develop mathematical models for estimating saturation flow rates at the stop line of signalized intersection due to Workzones in the vicinity, since the saturation flow rate is the most critical parameter in capacity analysis for signalized intersections. It was found by reference review that saturation flow rates are sensitively influenced by the location of Workzone, the number of lanes, cycle length and effective green time. Extensive microscopic simulation runs were also performed and compared to the those of mathematical models for model verification. Mathematical models were developed based on traffic flow theory and dualizing them by the location of workzones. And then each result produced by changing important parameter values was carefully examined and analyzed. Small but consistent differences in saturation flow rate values between mathematical models and simulations exist. However, the pattern of changes in saturation flow rates depending on each variable was similar.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.5_6
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• pp.228-237
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• 2007

displacement mapping enables us to add realistic details to polygonal meshes without changing geometry. We present a real-time artifacts-free inverse displacement mapping method. In each pixel, we construct a ray and trace the ray through the displacement map to find an intersection. To skip empty regions safely, we traverse the image pyramid of displacement map in top-down order. Furthermore, when the displacement map is enlarged, intersection with bilinear interpolated displacement map can be found. When the displacement map is at distance, our method supports mipmap-like prefiltering to enhance image quality and speed. Experimental results show that our method can produce correct images even at grazing view angles. Rendering speed of a test scene is over hundreds of frames per second and the influence of resolution of displacement map to rendering speed is little. Our method is simple enough to be added to existing virtual reality systems easily.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.3
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• pp.133-140
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• 2008

This paper proposes an effective k-D tree traversal algorithm for ray tracing on a GPU. The previous k-D tree traverse algorithm based on GPU uses bottom-up searching from a leaf to the root after failing to find the ray intersected primitive in the leaf node. During the bottom-up search the algorithm decides the current node is visited or not from the parent node. In such a way, we need to visit the parent node which was already visited and the duplicated bounding box intersection tests. The new k-D tree traverse algorithm reduces the brother and parent duplicated visit by using an efficient method which decides whether the brother node is already visited or not during the bottom-up search. Also the algorithm take place bounding box intersection tests only for the nodes which is not yet done. As a result our experiment shows the new algorithm is about 30% faster than the previous.

• The International Journal of Costume Culture
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• v.3 no.3
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• pp.212-222
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• 2000

This study intends to observe how the essential elements of art have changed Human's sense of beauty extending over the whole lives as well as fashion through the investigation of Light and Rays which have played a important role in giving birthe to the new trend of art within the upheaval age of various cultures. The peculiarities of which Futurism of Italy and Rayonism of Russia including Impressionism have a great role in giving birth to a new trend of art by means of the development of science technology are like these. Impressionists looked for the origin of the subtle harmony in nature within changes of sun-rays. The special feature of Impressionism paintings was to express the line of vision diversely according to changes of light rather than to focus on the line of vision with clear outlines. Henceforth, Neo-Impressionism which developed Impressionism more systematically leaded changes of Light and Rays more systematically and scientifically and maintained Divisionnisme techniques which extends to lead towards color and light through dividing and juxtaposing color. In the early 20th century Futurists tried to express dynamism through the interpenetration of light and revive color and light through the division techniques of color and persist an artificial light like eletricity rather than a natural light. Rayonism of Russia which was ifluenced from Impressionism and Futurism maintained intersection of reflecting rays which emerges from an object of things more deeply. This pursuit of light and rays also light and rays also appears as it is in modern fashion. First, it is the fashion which applied sun-rays persisted by Impressionists and expressed colors which show differently according to direction of light. Second, it is the fashion design which re-analyzed what Futurists expressed artificial light and rays. Third, it is the design which expressed Divisionnisme theory persisted by Impressionists and Futurists into fashion as it is and was made of being divided the form of glittering light into small dots. Fourth, it is the fashion design which applied Rayonists'work which applied intersection of reflected rays. Like this, it is aproved that the pursuit of light and rays expresses as it is in modern fashion of the 21st.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.8
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• pp.1698-1706
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• 1997

In this paper, we envisioned a multimedia object recognition system processing and combinig information from all available sources, such as 2-D, 3-D, color and sound data. Out of the overall system, we proposed 3-D information extraction and object recognition methods. Firstly, surfaces are classified by z-gradient from the range data, surface features are extracted using the intersection of normal vectors. Also feature relationship such as intersection angle and distance is established between the surfaces. Secondly, recognition is accomplished by matching process which is improtant step in the image understanding systems. Matching process is very improtant procedures because of more general and more efficient method is needed in the field of multimedia sytem. Therefore, we focused the proposal of matching process and in this article, first of all, we deal with the matching process of the 3-D object. Similarity measures are calculated.

• Geotechnical Engineering
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• v.14 no.5
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• pp.181-190
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• 1998

One-Dimensional Nonlinear Consolidation Model(NCM) ivas developed by using an Extended Power Function Model, which could represent the compressibility of soils. A nonlinear finite element program for NCM was developed to analyze the porewater pressure dissipation and the settlement of saturated soils. Parameters used in compressibility model could be easily obtained from conventional oedometer test data. This model has been applied to Yansan-Mulgum area for the comparison with the results of CONSOL program and that of Terzaghi theory. A Good The rates of consolidation predicted by this model and CONSOL were faster than that of conventional Tergaghi theory, for they consider the nonlinear characteristics of soils. Consolidation curves of this model were located between Terzaghi and CONSOL curves. Consolidation curves near drainage boundary, where effective stress valied rapidly, seemed to reflect the variations of compressibility of sails. Consolidation curves near drainage boundary obtained from this model were composed of two parabolic curves. Intersection of the parabolic curves occurred when effective stress reached the value of preconsolidation stress. Moreover, thin model could be used to represent the effect of magnitude of applied load. whereas CONSOL and Terazghi theory could not.