• Journal of Computational Design and Engineering
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• v.1 no.4
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• pp.272-288
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• 2014

This paper presents a two-step, semi-automated method for reconstructing a three-dimensional (3D) shape of the prostate from a 3D transrectal ultrasound (TRUS) image. While the method has been developed for prostate ultrasound imaging, it can potentially be applicable to any other organ of the body and other imaging modalities. The proposed method takes as input a 3D TRUS image and generates a watertight 3D surface model of the prostate. In the first step, the system lets the user visualize and navigate through the input volumetric image by displaying cross sectional views oriented in arbitrary directions. The user then draws partial/full contours on selected cross sectional views. In the second step, the method automatically generates a watertight 3D surface of the prostate by fitting a deformable spherical template to the set of user-specified contours. Since the method allows the user to select the best cross-sectional directions and draw only clearly recognizable partial or full contours, the user can avoid time-consuming and inaccurate guesswork on where prostate contours are located. By avoiding the usage of noisy, incomprehensible portions of the TRUS image, the proposed method yields more accurate prostate shapes than conventional methods that demand complete cross-sectional contours selected manually, or automatically using an image processing tool. Our experiments confirmed that a 3D watertight surface of the prostate can be generated within five minutes even from a volumetric image with a high level of speckles and shadow noises.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.3
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• pp.479-485
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• 2007

In this paper, a hierarchical simulation with an approximate implicit method is proposed in order to efficiently and plausibly animate mass-spring based cloth models. The proposed hierarchical simulation method can generate realistic motion of extremely fine mesh in interactive rate. The proposed technique employs a fast and stable simulation method which approximates the implicit integration. Although the approximate method is efficient, it is extremely inaccurate and shows excessively damped behavior. The hierarchical simulation technique proposed in this paper constructs multi-level mesh structure in order to represent the realistic appearance of cloth model and performs simulation on each level of the mesh with constraints that enforce some of the mass-points of current level to follow the movement of the previous level. This hierarchical method efficiently generates a plausible movement of a cloth model composed of large number of mass points. Moreover, this hierarchical method enables us to generate realistic wrinkles on the cloth, and the wrinkle pattern on the cloth model can be easily controlled because we can specify different contraction resistance force of springs according to their hierarchical level.

• Journal of the HCI Society of Korea
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• v.1 no.1
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• pp.1-8
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• 2006

We suggest a graphical representation of the tension flow in tonal music using a piecewise parametric curve, which is a function of time illustrating the changing degree of tension in a corresponding chord progression. The tension curve can be edited by using conventional curve editing techniques to reharmonize the original music with reflecting the user's demand to control the tension of music. We introduce three different methods to measure the tension of a chord in terms of a specific key, which can be used to represent the tension of the chord numerically. Then, by interpolating the series of numerical tension values, a tension curve is constructed. In this paper, we show the tension curve editing method can be effectively used in several interesting applications: enhancing or weakening the overall feeling of tension in a whole song, the local control of tension in a specific region of music, the progressive transition of tension flow from source to target chord progressions, and natural connection of two songs with maintaining the smoothness of the tension flow. Our work shows the possibility of controlling the perceptual factor (tension) in music by using numerical methods. Most of the computations used in this paper are not expensive so they can be calculated in real time. We think that an interesting application of our method is an interactive modification of tension in background music according to the user's emotion or current scenario in the interactive environments such as games.

• Journal of Korea Game Society
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• v.7 no.1
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• pp.31-42
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• 2007

In the natural world, most materials such as skin, marble and cloth are translucent. Their appearance is smooth and soft compared with metals or mirrors. In this paper, we propose a new GPU based hierarchical rendering technique for translucent materials, based on the dipole diffusion approximation, at interactive rates. Information of incident light, position, normal, and irradiance, on the surfaces are stored into 2D textures by rendering from a primary light view. Huge numbers of pixel photons are clustered into quad-tree image pyramids. Each pixel, we select clusters (sets of photons), and then we approximate multiple subsurface scattering term with the clusters. We also introduce a novel hierarchical screen-space interpolation technique by exploiting spatial coherence with early-z culling on the GPU. We also build image pyramids of the screen using mipmap and pixel shader. Each pixel of the pyramids is stores position, normal and spatial similarity of children pixels. If a pixel's the similarity is high, we render the pixel and interpolate the pixel to multiple pixels. Result images show that our method can interactively render deformable translucent objects by approximating hundreds of thousand photons with only hundreds clusters without any preprocessing. We use an image-space approach for entire process on the GPU, thus our method is less dependent to scene complexity.

• Journal of the Korea Society of Computer and Information
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• v.16 no.7
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• pp.67-76
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• 2011

Recently, researches for semantic annotation methods which represent and search objects included in video data, have been briskly activated since video starts to be popularized as types for interactive contents. Different location data occurs at each frame because coordinates of moving objects are changed with the course of time. Saving the location data for objects of every frame is too ineffective. Thus, it is needed to compress and represent effectively. This paper suggests two methods; the first, ontology modeling for moving objects to make users intuitively understandable for the information, the second, to reduce the amount of data for annotating moving objects by using cubic spline interpolation. To verify efficiency of the suggested method, we implemented the interactive video system and then compared with each video dataset based on sampling intervals. The result follows : when we got samples of coordinate less than every 15 frame, it showed that could save up to 80% amount of data storage; moreover, maximum of error deviation was under 31 pixels and the average was less than 4 pixels.

• Korean Journal of Remote Sensing
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• v.14 no.4
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• pp.376-391
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• 1998

Images from satellites will have 1 to 3 meter ground resolution and will be very useful for analyzing current status of earth surface. An image processing system named GeoWatch with more intelligent image processing algorithms has been designed and implemented to support the detailed analysis of the land surface using high-resolution satellite imagery. The GeoWatch is a valuable tool for satellite image processing such as digitizing, geometric correction using ground control points, interactive enhancement, various transforms, arithmetic operations, calculating vegetation indices. It can be used for investigating various facts such as the change detection, land cover classification, capacity estimation of the industrial complex, urban information extraction, etc. using more intelligent analysis method with a variety of visual techniques. The strong points of this system are flexible algorithm-save-method for efficient handling of large size images (e.g. full scenes), automatic menu generation and powerful visual programming environment. Most of the existing image processing systems use general graphic user interfaces. In this paper we adopted visual program language for remotely sensed image processing for its powerful programmability and ease of use. This system is an integrated raster/vector analysis system and equipped with many useful functions such as vector overlay, flight simulation, 3D display, and object modeling techniques, etc. In addition to the modules for image and digital signal processing, the system provides many other utilities such as a toolbox and an interactive image editor. This paper also presents several cases of image analysis methods with AI (Artificial Intelligent) technique and design concept for visual programming environment.

• Journal of Digital Convergence
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• v.13 no.8
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• pp.289-294
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• 2015

This paper proposes an autonomous machine learning method applicable to the BCI(Brain-Computer Interface) is based on the self-organizing Kohonen method, one of the exemplary method of unsupervised learning. In addition we propose control method of learning region and self machine learning rule using an interactive function. The learning region control and machine learning was used to control the side effects caused by interaction function that is based on the self-organizing Kohonen method. After determining the winner neuron, we decided to adjust the connection weights based on the learning rules, and learning region is gradually decreased as the number of learning is increased by the learning. So we proposed the autonomous machine learning to reach to the network equilibrium state by reducing the flow toward the input to weights of output layer neurons.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.461-468
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• 2008

The needs for visualizing interactive multimedia contents on portable devices with realistic three dimensional shapes are increasing as new ubiquitous services are coming into reality. Especially in digital fashion applications with virtual reality technologies for clothes of various forms on different avatars, it is required to provide very high quality visual models over mobile networks. Due to limited network bandwidths and memory spaces of portable devices, it is very difficult to transmit visual data effectively and render realistic appearance of three dimensional images. In this thesis, we propose a compression method to reduce three dimensional data for digital fashion applications. The three dimensional model includes animation of avatar which require very large amounts of data over time. Our proposed method utilizes temporal and spatial coherence of animation data, to reduce the amount. By grouping vertices from three dimensional models, the entire animation is represented by a movement path of a few representative vertices. The existing three dimensional model compression approaches can get benefits from the proposed method by reducing the compression sources through grouping. We expect that the proposed method to be applied not only to three dimensional garment animations but also to generic deformable objects.

• Journal of the Korea Computer Graphics Society
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• v.5 no.2
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• pp.9-23
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• 1999

Visibility preprocessing is a useful method to reduce the complexity of scenes to be processed in real-time, and so enhances the overall rendering performance for interactive visualization of virtual environments. In this paper, we propose an efficient visibility preprocessing method. In the proposed method, we assume that navigatable areas in virtual environments are partitioned into rectangular parallelpiped cells or sub-worlds. To preprocess the visibility of each polygon for a given partitioned cell, we should determine at least the area-to-area visibility. This is inherently a four-dimensional problem. We efficiently express four-dimensional visibility information on two-dimensional spaces and keep it within a ternary tree, which is conceptually similar to a BSP(Binary Space Partitioning) tree, by exploiting the characteristics of conservative visibility. The proposed method is able to efficiently handle more general environments like urban scenes, and remove invisible polygons jointly blocked by multiple occluders. The proposed method requires O(nm) time and O(n+m) space. By selecting a suitable value for m, users can select a suitable level of trade-off between the preprocessing time and the quality of the computational result.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.7
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• pp.1020-1027
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• 2015

The combined effect of tumbling marination methods (vacuum continuous tumbling marination, CT; vacuum intermittent tumbling marination, IT) and effective tumbling time (4, 6, 8, and 10 h) on the water status and protein properties of prepared pork chops was investigated. Results showed that regardless of tumbling time, CT method significantly decreased the muscle fiber diameter (MD) and significantly increased the total moisture content, product yield, salt soluble proteins (SSP) solubility, immobilized water component (p<0.05) compared with IT method. With the effective tumbling time increased from 4 h to 10 h, the fat content and the MD were significantly decreased (p<0.05), whereas the SSP solubility of prepared pork chops increased firstly and then decreased. Besides, an interactive effect between CT method and effective tumbling time was also observed for the chemical composition and proportion of immobilized water (p<0.05). These results demonstrated that CT method of 8 h was the most beneficial for improving the muscle structure and water distribution status, increasing the water-binding capacity and accelerating the marinade efficiency of pork chops; and thus, it should be chosen as the most optimal treatment method for the processing production of prepared pork chops.