• The Journal of the Korea Contents Association
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• v.11 no.1
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• pp.16-25
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• 2011

Some context is characterized by a single event in computing environment, but many other contexts are determined by a lot of things which occur with a space and a time. The Realtime Embedded System context-awareness service that interacts with the physical space can have property such as time. The exceptional behaviors of the system that interact with physical space can result in critical damage and cause danger to the operation of an embedded system. we propose an approach which should include spatio-temporal property and exceptional management in the context model, and verify its effectiveness using an expanded Petri-Net. The context-awareness service modeling of an embedded system is discussed the properties of model such as basic Petri-Net, patterned Petri-Net, or Spatio-temporal Petri-Net for the exceptional behaviors of the system. The proposed methodology demonstrated using an example that is emergency medical service. The use of expanded Petri-Net will contribute not only to develop the application but also to model the spatio-temporal context awareness for the exceptional handling.

• Journal of Korea Game Society
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• v.10 no.4
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• pp.81-90
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• 2010

In this paper, an efficient method is proposed to produce photorealistic images of woven fabrics without empirical data such as the measured BRDFs(bidirectional reflectance distribution functions). The proposed method is applicable both to ray tracer based offline renderers and to realtime applications such as games. The proposed method models the reflectance properties of woven fabric with alternating anisotropy and deformed MDF(microfacet distribution function). The procedural modeling of the yarn structure effectively and efficiently reproduces plausible rendering of woven fabric. The experimental results show the proposed method can be successfully applied to photorealistic rendering of diverse woven fabric materials even in interactive applications.

• Journal of KIISE:Software and Applications
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• v.34 no.1
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• pp.59-69
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• 2007

In the video with a various environment, background modeling is important for extraction and recognition the moving object. For this object recognition, many methods of the background modeling are proposed in a process of preprocess. Among these there is a Kumar method which represents the Queue-based background modeling. Because this has a fixed period of updating examination of the frame, there is a limit for various system. This paper use a background modeling based on the queue. We propose the method that major parameters are decided as adaptive by background model. They are the queue size of the sliding window, the sire of grouping by the brightness of the visual and the period of updating examination of the frame. In order to determine the factors, in every process, RCO (Ratio of Correct Object), REO (Ratio of Error Object) and UR (Update Ratio) are considered to be the standard of evaluation. The proposed method can improve the existing techniques of the background modeling which is unfit for the real-time processing and recognize the object more efficient.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2009.04a
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• pp.181-186
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• 2009

Recently, the consuming efficiency of energy and natural resources has been a hot issue because of the continuous increasing of energy consumption and soaring of international oil prices. We tried to seek an action plan for the government's new paradigm 'Low-Carbon, Green Growth' by consuming energy efficiently and improving in energy management based on ubiquitous IT technologies. In this study, the library survey method is adopted for this study and IP-USN(internet protocol based ubiquitous sensor network) is considered as a core technology among various ubiquitous IT technologies. The purpose of this study is to deliver a method of energy management through integrating the context information gathered from sensors with digital space models and visualizing them together. The details are to survey the technologies of digital space modeling, USN based monitoring, building energy management and to integrate these technologies all together. This study will contribute to the enhancement of efficient building energy management by grasping the accurate situation of energy consuming in the building in realtime and minimizing unnecessary energy wastes.

• Proceedings of the Korea Society for Simulation Conference
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• 2002.11a
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• pp.163-170
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• 2002

Terrain surfaces have to be modeled in very detail and wheel-surface contacting geometry must be well defined in order to obtain proper ground-reaction and friction forces for realistic simulation of off-road vehicles. Delaunay triangulation is one of the most widely used methods in modeling 3-dimensional terrain surfaces, and T-search is a relevant algorithm for searching resulting triangular polygons. The T-search method searches polygons in successive order and may not allow real-time computation of off-road vehicle dynamics if the terrain is modeled with many polygons, depending on the computer performance used in the simulation. In order to accelerate the searching speed of T-search, a terrain database of triangular polygons is modeled in multi-levels by adopting the LOD (Level of Detail) method used in realtime computer graphics. Simulation results show that the new LOD search is effective in shortening the required computing time. The LOD search can be even further accelerated by introducing an NN (Neural Network) algorithm, in the cases where a appropriate range of moving paths can be predicted by cultual information of the simulated terrain, such as lakes, houses, etc.. Numerical tests show that LOD-NN search almost double the speed of the original T-search.

• Asian Journal of Atmospheric Environment
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• v.8 no.2
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• pp.108-114
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• 2014

In the companion paper (Lee et al., 2012), it was showed that CMAQ simulation using a lateral boundary conditions (LBCs) derived from RAQMS-CMAQ linkage, compared to the CMAQ results with the default CMAQ LBCs, improved ozone simulations in the conterminous US domain. In the present paper, the study is extended to investigate the influence of LBCs on PM2.5 simulation. MM5-SMOKE-CMAQ modeling system was used for meteorological field generation, emissions preparation and air quality simulations, respectively. Realtime Air Quality Modeling System (RAQMS) model assimilated with satellite observations were used to generate the CMAQ-ready LBCs. CMAQ PM2.5 simulations with RAQMS LBCs and predefined LBCs were compared with U.S. EPA Air Quality System (AQS) measurements. Mean PM2.5 lateral boundary conditions taken from RAQMS outputs showed strong variations both in the horizontal grid and vertical layers in the northern and western boundaries and affected the results of CMAQ PM2.5 predictions. CMAQ with RAQMS LBCs could improve CMAQ PM2.5 predictions resulting in the improvement of index of agreement from 0.38 to 0.63.

• Journal of KIBIM
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• v.10 no.4
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• pp.89-97
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• 2020

The purpose of this study is to identify the problems of the currently used 3D spatial information utilization system to realize a more accurate landscape and to establish a user-oriented environment to improve the utilization plan for future landscape evaluation. As citizens' interest in urban landscapes with strong public characteristics increases and the speed of urban development also increases, more suitable simulation methods for landscape management are required. Nevertheless, there are many cases of inconvenient correction according to development changes along with many errors in various steps for creating landscape simulation. Therefore, in performing landscape deliberation according to development, it is necessary to create more accurate and efficient landscape simulation, and if changes occur after the initial deliberation, a process that can quickly and conveniently correct and supplement data is needed. In addition, it is necessary to create landscape simulation so that the created modeling source can be used by being compatible with other application programs. In this study, a method of constructing a more accurate and efficient simulation at the time of initial deliberation and a method of creating a landscape simulation model for rapid response to a plan that is changed at the time of re-deliberation are described.

• Journal of Korea Multimedia Society
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• v.6 no.7
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• pp.1286-1301
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• 2003

This paper introduces segmentation based environment modeling method and integration method using multiple environment map for constructing the realtime image-based panoramic navigation system. The segmentation-based environment modeling method is easy to implement on the environment map and can be used for environment modeling by extracting the depth value by the segmentation of the environment map. However, an environment model that is constructed using a single environment map has the problem of a blurring effect caused by the fixed resolution, and the stretching effect of the 3D model caused when information that does not exist on the environment map occurs due to the occlusion. In this paper, we suggest environment models integration method using multiple environment map to resolve the above problem. This method can express parallax effect and expand the environment model to express wide range of environment. The segmentation-based environment modeling method using multiple environment map can build a detail model with optimal resolution.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.5
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• pp.947-956
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• 2021

As an interest in metaverse increases, there are many studies to apply virtual reality to indirect experiences. Virtual reality is increasingly being used not only for entertainment such as games but also for educational content. A key technology of indirect experience is modeling an object to provide a realistic experience to the user. Natural environments such as tidal flats change with time, and many living things also live there. In this paper, we propose a method for creating experiential content that accurately models the ecological environment of tidal flats. The proposed method explains how to naturally model the temporal change of tidal flats. We also explain how to model a crab, a creature that inhabits the tidal flat, in the forms of an NPC using the behavior tree. Implementation results show that the proposed method uses simple algorithms but expresses the shapes of tidal flats well.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.490-497
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• 2011

When operating Express and Standard trains, which run with two different scheduled time, in a single line with limited number of side tracks for overtaking standard trains, it is required to have various modeling methodologies and simulations in order to calculate an optimum headway to maximize the capacity of the line with the best scheduled time. Especially it is inevitable that following trains have to slow down or stop in the middle of their operations due to the preceding trains, in case it is inappropriate controlled about either in which station an overtaking should be taken or how long it should be. This study is to analyze TPS data which have been produced with a simulation program which the team has invented to optimize Express and Standard mixed traffic plan and to introduce an algorism which shows detected conflict data, calculates appropriate dwell time after getting overtaken and helps to decide stations for overtaking.