• Journal of the Korean Association of Geographic Information Studies
• /
• v.15 no.4
• /
• pp.104-113
• /
• 2012

Followed by that HTML5(Hypertext Markup Language5) was introduced, many kinds of program and services based on this have been developed and released. HTML5 is technical standard specifications for cross platform for personal computers and mobile devices so that it is expected that continuing progress and wide application in the both sides of the academic and the industrial fields increase. This study is to design and implement a mobile application program for overlay rendering with DEM and other geo-based image sets using HTML5 WebGL for 3D graphic processing on web environment. Particularly, the blending technique was used for overlay processing with multiple images. Among available WebGL frameworks, CubicVR.js was adopted, and various blending techniques were provided in the user interface for general users. For the actual application in the study area around the Sejong city, serveral types of geo-based data sets were used and processed: KOMPSAT-2 images, ALOS PALSAR SAR images, and grid data by environment measurements. While, DEM for 3D viewing with these geo-based images was produced using contour information of the digital map sets. This work demonstrates possibilities that new types of contents and service system using geo-based images can be extracted and applied.

• The Journal of the Acoustical Society of Korea
• /
• v.20 no.6
• /
• pp.94-103
• /
• 2001

The goal of using numerical methods in this study is two-fold: to replicate a set of measured, individualized HRTFs by a computer simulation, and also to visualise the resultant sound field around the head. Two methods can be wed: the Boundary Element Method (BEM) and the Infinite-Finite Element Method (IFEM). This paper presents the results of a preliminary study carried out on a KEMAR dummy-head, the geometry of which was captured with a high accuracy 3-D laser scanner and digitiser. The scanned computer model was converted to a few valid BEM and IFEM meshes with different polygon resolutions, enabling us to optimise the simulation for different frequency ranges. The results show a good agreement between simulations and measurements of the sound pressure at the blocked ear-canal of the dummy-head. The principle of reciprocity provides an effect method to simulate HRTF database. The BEM was also used to investigate the total sound field around the head, providing a tool to visualise the sound field for different arrangements of virtual acoustic imaging systems.

• Journal of KIISE:Computer Systems and Theory
• /
• v.33 no.1_2
• /
• pp.1-14
• /
• 2006

Sort-last parallel rendering using a cluster of GPUs has been widely used as an efficient method for visualizing large- scale volume datasets. The performance of this method is constrained by load balancing when data parallelism is included. In previous works static partitioning could lead to self-balance when only task level parallelism is included. In this paper, we present a load balancing scheme that adapts to the characteristic of volume dataset when data parallelism is also employed. We effectively combine the hierarchical data structures (octree and BSP tree) in order to skip empty regions and distribute workload to corresponding rendering nodes. Moreover, we also exploit a 3D clustering method to determine visibility order and save the AGP bandwidths on each rendering node. Experimental results show that our scheme can achieve significant performance gains compared with traditional static load distribution schemes.

• Journal of Korea Spatial Information System Society
• /
• v.5 no.1 s.9
• /
• pp.83-89
• /
• 2003

The GIS which is analysis of the real world to construction of 3D virtual city develop s in rapid growth. 3D virtual city is simulated by use of a GIS, Computer graphics, virtual reality and Spatial database. In this paper 3D topographical basemap which have the geographic coordinate of world was constructed by digital map. And build the Cyber city with combining the building that have elevation and 3D topographical basemap. By using server/client system for the cyber city. 3D cyber city web service implemented. We proposed the hybrid base web service method rather than the image or vector base web service. By the spatial and attribute search in the 3D Cyber City, overcome the existing simple visibility of Web 3D technology, and exhibited development direction to the Web 3D GIS.

• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.765-768
• /
• 2003

The objective of the present study was to visualize the pulsatile flow field in a branching model by using the high-resolution PIV system. A bifurcated flow system was built for the experiments in the pulsatile flow. Harvard pulsatile pump was used to generate the pulsatile velocity waveforms. Conifer powder as the tracing particles was added to water to visualize the flow fields. Two consecutive particle images at several cross sections of the flow filed were captured by the CCD cameras ($1K{\ast}1K$ and $640{\ast}480$). The results after the image processing clearly showed the recirculation zones and the formation of the paired secondary flows from the distal to the apex in the bifurcated model. The results also indicated that the flow velocities in the inner wall moved faster than those in the outer wall due to the inertial force effects and the helical motions generated in the branch flows as the flow proceeded toward the outer wall. While the PIV images from the $1K{\ast}1K$ camera were closer to the simulation results thantheimagesfromthe640${\ast}$480camera,bothresultsofthePIVexperimentsusingthetwocamerasgenerallyagreed quitewellwiththeresultsfromthenumericalsimulation.

• Journal of the Society of Naval Architects of Korea
• /
• v.42 no.5 s.143
• /
• pp.487-492
• /
• 2005

The structural intensity analysis, which calculates vibration energy flow from vibratory velocity and internal force of a structure, can give information on sources' power, dominant transmission path and sink of vibration energy. In this study, we present a system for structural intensity analysis and visualization to apply for anti-vibration design of ship structures. The system calculates structural intensity from the results of forced vibration analysis and visualize the intensity using a general purpose finite element analysis program MSC/Nastran and its pre- and post-processor program. To demonstrate the analysis and visualization capability of the presented system, we show and discuss the results of structural intensity analysis for a cross-stiffened plate and a 70,500 OW crude oil tanker

• Journal of the Korean Association of Geographic Information Studies
• /
• v.8 no.4
• /
• pp.155-164
• /
• 2005

The coast has been known as very vulnerable area. This area has nature disasters such as typhoon, tidal wave, flood and storm almost every year. In this study, coast vulnerable area information management system was developed to manage the coastal facilities and vulnerable area through Web GIS. This system is able to visualize the damage area and support the official work related to coast as efficient DSS(Decision Supporting System). Moreover, the foundation for domestic coast information management is expected by acquiring less cost and time. For this, GIS DB was first constructed by acquiring damage factor data such as typhoon, tidal wave, flood and storm. Then GIS analysis methods and high resolution satellite images are used to possibly present the results of retrieve as table, map, graph, inundation simulation in real time.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.14 no.3
• /
• pp.96-109
• /
• 2011

Recently, the geographic information system(GIS) is generally used in various fields with the development of information and communication technology, with expansion of its applications and utilization scope. Especially, utilizing GIS is expected to have positive effects on the geography learning and more helpful for the geographic information observation compared to the picture or 2D based media. The effective visualization of complex geographic data does not only take realization of its visual information but also increases the human ability in analysis and understanding to use the geographic information. In this paper, we examine a method to develop the geography learning contents based on the technology with augmented reality and GIS, and then we have a case study for various kinds of visualization techniques and examples to use in geography learning situation. Moreover, we introduce an example of the manufacturing process from the existing GIS data to augmented reality based geography learning system. From the above, we show that the usefulness of our method is applicable for effective visualization of the three-dimensional geographic information in the geography learning environment.

• The KIPS Transactions:PartB
• /
• v.17B no.3
• /
• pp.183-188
• /
• 2010

A factorization-based 3D reconstruction system is realized to recover 3D scene from an image sequence. The image sequence is captured from uncalibrated perspective camera from several views. Many matched feature points over all images are obtained by feature tracking method. Then, these data are supplied to the 3D reconstruction module to obtain the projective reconstruction. Projective reconstruction is converted to Euclidean reconstruction by enforcing several metric constraints. After many triangular meshes are obtained, realistic reconstruction of 3D models are finished by texture mapping. The developed system is implemented in C++, and Qt library is used to implement the system user interface. OpenGL graphics library is used to realize the texture mapping routine and the model visualization program. Experimental results using synthetic and real image data are included to demonstrate the effectiveness of the developed system.

• The KIPS Transactions:PartA
• /
• v.10A no.1
• /
• pp.59-68
• /
• 2003

3-D data modeling of a volumetric scattered data is highly demanded for geological structure inspection, environment visualization and supersonic testing. The data used in these area are generally irregularly scattered in a volume data space, which are much different from the structured points data (cuberille data) used in Marching cube algorithm. In this paper, first we explore a volume modeling method for the scattered data based on tetrahedral domain. Next we propose a method for solving the ambiguity of tetrahedral domain decision using asymptotic decider criterion. Last we implement a simple visualization system based on the proposed asymptotic decider criterion and compare it with a system based on sphere criterion. In deciding tetrahedral domain, sphere criterion considers only positional values but asymptotic decider criterion considers not only positional values but also functional values, so asymptotic decider criterion is more accurate on deciding tetrahedral domain than sphere criterion.