• Progress in Medical Physics
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• v.14 no.2
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• pp.90-98
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• 2003

Purpose : A new virtual simulation technique for craniospinal irradiation (CSI) that uses a CT-simulator was developed to improve the accuracy of field and shielding placement as well as patient positioning. Materials and Methods : A CT simulator (CT-SIM) and a 3-D conformal radiation treatment planning system (3D-CRT) were used to develop CSI. The head and neck were immobilized with a thermoplastic mask while the rest of the body was immobilized with a Vac-Loc. A volumetric image was then obtained with the CT simulator. In order to improve the reproducibility of the setup, datum lines and points were marked on the head and body. Virtual fluoroscopy was performed with the removal of visual obstacles, such as the treatment table or immobilization devices. After virtual simulation, the treatment isocenters of each field were marked on the body and on the immobilization devices at the conventional simulation room. Each treatment fields was confirmed by comparing the fluoroscopy images with the digitally reconstructed radiography (DRR) and digitally composited radiography (DCR) images from virtual simulation. Port verification films from the first treatment were also compared with the DRR/DCR images for geometric verification. Results : We successfully performed virtual simulations on 11 CSI patients by CT-SIM. It took less than 20 minutes to affix the immobilization devices and to obtain the volumetric images of the entire body. In the absence of the patient, virtual simulation of all fields took 20 min. The DRRs were in agreement with simulation films to within 5 mm. This not only reducee inconveniences to the patients, but also eliminated position-shift variables attendant during the long conventional simulation process. In addition, by obtaining CT volumetric image, critical organs, such as the eyes and the spinal cord, were better defined, and the accuracy of the port designs and shielding was improved. Differences between the DRRs and the portal films were less than 3 m in the vertebral contour. Conclusion : Our analysis showed that CT simulation of craniospinal fields was accurate. In addition, CT simulation reduced the duration of the patient's immobility. During the planning process. This technique can improve accuracy in field placement and shielding by using three-dimensional CT-aided localization of critical and target structures. Overall, it has improved staff efficiency and resource utilization by standard protocol for craniospinal irradiation.

• Journal of the Korea Computer Graphics Society
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• v.8 no.2
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• pp.31-38
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• 2002

This paper presents a method for real-time 3D Sumi-e rendering us ing normal graphics hardware. Sumi-e is one of the traditional oriental painting styles. Most research on Sumi-e paintings has focused on 2D or :2.5D Sumi-e brushwork simulation. On these systems. complicated user's hand drawing is required to generate the image of Sumi-e effects. and it can render the 2D or 2.5D Sumi-e images only. We present an automated rendering system for 3D image of Sumi-e painting. It uses 3D common object as an input data and does not need any additional input of user brushwork. Especially for the real-time rendering. hardware-accelerated algorithm for Sumi-e rendering is newly suggested in our system. It is designed with efficiency for customer level graphics hard ware. The results of this paper show that the features of traditional Sumi-e painting are successfully modeled and that 3D Sumi-e painting is rendered in real-time effectively.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.183-186
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• 2003

A vision sensor should be calibrated prior to infer a Euclidian shape reconstruction. A point to point calibration. also referred to as a hard calibration, estimates calibration parameters by means of a set of 3D to 2D point pairs. We proposed a new method for determining a set of 3D to 2D pairs for the structured light hard calibration. It is simply determined based on epipolar geometry between camera image plane and projector plane, and a projector calibrating grid pattern. The projector calibration is divided two stages; world 3D data acquisition Stage and corresponding 2D data acquisition stage. After 3D data points are derived using cross ratio, corresponding 2D point in the projector plane can be determined by the fundamental matrix and horizontal grid ID of a projector calibrating pattern. Euclidian reconstruction can be achieved by linear triangulation. and experimental results from simulation are presented.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.1
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• pp.191-197
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• 2013

Conventional CT and MRI scans produce cross-section slices of body that are viewed sequentially by radiologists who must imagine or extrapolate from these views what the 3 dimensional anatomy should be. By using sophisticated algorithm and high performance computing, these cross-sections may be rendered as direct 3D representations of human anatomy. The 2D medical image analysis forced to use time-consuming, subjective, error-prone manual techniques, such as slice tracing and region painting, for extracting regions of interest. To overcome the drawbacks of 2D medical image analysis, combining with medical image processing, 3D visualization is essential for extracting anatomical structures and making measurements. We used the gray-level thresholding, region growing, contour following, deformable model to segment human organ and used the feature vectors from texture analysis to detect harmful cancer. We used the perspective projection and marching cube algorithm to render the surface from volumetric MR and CT image data. The 3D visualization of human anatomy and segmented human organ provides valuable benefits for radiation treatment planning, surgical planning, surgery simulation, image guided surgery and interventional imaging applications.

• Journal of Fashion Business
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• v.12 no.6
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• pp.46-60
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• 2008

Lyocell is a regenerated cellulosic fiber manufactured by an environmentally friendly process. The major advantages of lyocell are the excellent drape forming property, the genuine bulkiness, smooth surface, and high dry/wet tenacities. However, one drawback of lyocell is its fibrillation property, which would degrade its aesthetic quality and lower the consumer satisfaction. In our previous studies, lyocell was treated with epichlorohydrin, a non-formalin based crosslinker, to reduce its fibrillation tendency. To investigate the changes of physical properties upon ECH-treatment, the hand characteristics of ECH-treated fabric were observed using KES-FB system and the 3D-virtual sewing image of the fabrics were obtained using 3D CAD simulation system in this study. Since epichlorohydrin(ECH) treatment was conducted in the alkaline medium, the weight reduction was observed in all treated lyocell. The treated lyocell became light, smooth and flexible in spite of ECH crosslinker application. LT and RT in tensile property upon the ECH treatment did not change significantly, however, EMT and WT in the tensile property increased. The significant decrease in bending rigidity was resulted in all ECH-treated lyocell, which is the result of the weight loss upon the alkali condition of ECH treatment. The bending rigidity increased again in the ECH 30% treated lyocell, however, the B value is still lower than the original. Therefore, the ECH-treated lyocell would be more stretchable and softer than the original. Shear rigidity was also decreased in all ECH-treated lyocell, which would result in more drape and body fitting when it is made as a garment. The ECH-treated fabric showed the softer smoother surface according to SMD value from KES evaluation. The virtual 3D sewing image of the ECH-treated lyocell did not show a significant change from that of the original except ECH 30% treated lyocell. ECH 30% treated lyocell showed a stiffer and more puckered image than the original.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.5
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• pp.1096-1108
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• 1996

In this paper, we propose a temporal adaptive tranform 3D SBC coder with motion compensation, exploiting redundancy in the temporal domain. We propose a temporal adaptivity measure, by which the R-D optimal temporal transform can be chaosen. The base temporal subband frame is coded using H.261-like MC-DCT coder, while the higher temporal subband frames are coded using the 2D adaptive wavelet packet bases, considering the various energy distribution which results from the temporal variation. In encoding the subbands, we employ adaptive scanning methods, uniform step-size quantization with VLC, and coded/not-coded flag reduction technique using the quadtree structure. From the simulation results, the proposed adaptive 3D subband coder shows about 0.29~3.14 dB gain over the H.261 and the fixed 3D subband coder techniques.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.2
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• pp.128-134
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• 2014

Infrared thermography is an emerging approach to non-contact, non-intrusive, and non-destructive inspection of various solid materials such as metals, composites, and semiconductors for industrial and research interests. In this study, data processing was applied to infrared thermography measurements to detect defects in metals that were widely used in industrial fields. When analyzing experimental data from infrared thermographic testing, raw images were often not appropriate. Thus, various data analysis methods were used at the pre-processing and processing levels in data processing programs for quantitative analysis of defect detection and characterization; these increased the infrared non-destructive testing capabilities since subtle defects signature became apparent. A 3D finite element simulation was performed to verify and analyze the data obtained from both the experiment and the image processing techniques.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.682-685
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• 2002

In this paper, we defined necessary operations and functional blocks of a multiplexer for 3-D video systems and present our multiplexer design. We adopted the ITU-T's recommendation(H.222.0) to define the operations and functions of the multiplexer and explained the data structures and details of the design for multiview image processing. The data structure of TS(Transport Stream) and PES (Packetized Elementary Stream) in ITU-T Recommendation H.222.0 does not fit our multiview image processing system, because this recommendation is fur wide scope of transmission of non-telephone signals. Therefore, we modified these TS and PES stream structures. The TS is modified to DSS(3D System Stream) and PES is modified to SPDU(DSS Program Data Unit). We constructed the multiplexer through these modified DSS and SPDU. The number of multiview image channels is nine, and the image class employed is MPEG-2 SD(Standard Definition) level which requires a bandwidth of 2∼6 Mbps. The required clock speed should be faster than 54(= 6 ${\times}$ 9)㎒ which is the outer interface clock speed. The inside part of the multiplexer requires a clock speed of only 1/8 of 54㎒, since the inside part of the multiplexer operates by the unit of byte. we used ALTERA Quartus II and the FPGA verification for the simulation.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.204-207
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• 2002

The current paper proposes a new multispectral image data compression algorithm that can efficiently reduce spatial and spectral redundancies by applying classified prediction, a Karhunen-Loeve transform (KLT), and the three-dimensional set partitioning in hierarchical trees (3-D SPIHT) algorithm In the wavelet transform (WT) domain. The classification is performed in the WT domain to exploit the interband classified dependency, while the resulting class information is used for the interband prediction. The residual image data on the prediction errors between the original image data and the predicted image data is decorrelated by a KLT. Finally, the 3D-SPIHT algorithm is used to encode the transformed coefficients listed in a descending order spatially and spectrally as a result of the WT and KLT. Simulation results showed that the reconstructed images after using the proposed algorithm exhibited a better quality and higher compression ratio than those using conventional algorithms.

• The Journal of the Korea Contents Association
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• v.4 no.2
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• pp.7-12
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• 2004

The technique of birdeye image generation of terrain through the use of satellite digital images and digital maps are very important elements and have applications in fanning establishment as well as the actual design of several construction works in complex fields. This paper studies stereo perspective image generation as a possibility through 3-dimensional analysis combined with digital elevation data and remotely sensed images. For this, first of all, ortho-images generated by very accurate GCP and DEM from contour file makes 3-dimensional terrain analysis possible and allows stereo­viewing at the highway construction planning sites. So, we developed the technical methods for the 3-dimensional approach on the planning sites of highways by use of perspective orthoimages. From this research, diverse terrain analysis is possible through stereo perspective image generation, and can leads to various application in road construction through gain study results from access to realtime virtual spatial on the objects area in korea.