The purpose of this research lies in developing techniques and systems to create actual three-dimensional shape as origami or paper craft. First, we discuss the two curves which presents inherent feature of the surface, called as “zero curve Gaussian curvature curve” and “the extreme curvature curve”, are useful in polygonization of the free-form as a non-developable surface. Then, we discuss a design system of the three-dimensional origami which uses the curved folding. The technique of curved folding makes origami possible to smooth surfaces. And we indicate that shapes can be obtained from the three-dimensional piece of paper with a new curved folding, when you convert a portion of the developable surface reflection across the plane of any developable surface.
We propose and the development a specialized support system of learning for catheterization. Specifically, I developed the support system to make teaching materials with using a radioscopy movie, a hand movie of the doctor, and a view of operation room movie. The editing contents gave movies the explanation information about operation and a category as query. Then, this system supported it. The merit of this system is more reasonable than the simulation that was in widespread now. In addition, We consider that provided information of the finger-tip with markers and two cameras are useful for learning.
In this paper, we describe an automatic extraction method of the bone axes of femur and tibia using inferior limb image though it needs leg information on a left leg or a right leg beforehand. Moreover, our image processing method is applicable for virtual CR image generated by CT image. Since the method can be applied for both front and side virtual CR images from CT image, accurate 3D coordinates of 3D bone axis are calculated efficiently. The bone axis information is effective for labor saving measure for doctors, precise surgery planning, and useful for 2D and 3D implant template placements. Moreover, since 3D bone axis is precisely defined in 3D space, it is possible to place bone cutting planes on orthogonal line of bone axis, to decide rotation angles of implants, and to compare each loading axis and bone axis.
These days, there are many researches related to fluid, which is expressed with particle methods, and one of them is a research on bubbles. Some are about the expression of bubbles, which flow in the water, move up, and disappear at random when they emerge on the water surface. These researches, however, are not the simulation based on the physical phenomena. Therefore, we have simulated bubble disappearance with physical based model using particle methods. In the model, a bubble is composed of air and water particles, and water particles that touch air particles constructing the bubble inside on water surface are considered as bubble surface particles. Then, bubbles can move up on the water surface and disappear by considering surface tension and gravity that work on the bubble surface particle.
As for the research of recognition of 3D tracks of objects, both techniques and concrete application examples are extremely few compared with that of 2D tracks which have many practical applications such as online character recognition. To overcome this problem, we previously examined the recognition of the sign language operation using Procrustes analysis. Procrustes analysis is a technique to compare two ordered data under various linear transformations. There are only several applications of Procrustes analysis in pattern recognition though it has a great advantage in flexibility to pattern deformation. This paper describes a method to give some solutions of the problems in symmetrization of the recognition function and in generation of the standard pattern. An experiment is conducted and the result shows the effectiveness of our proposed method.
Digital archives are archives in which collections are stored in electronic formats to improve accessibility to the information without damages to the original collection. Hakodate area, where our university is located in, has many collections of historical records including such as documents, printed materials, photographs, in public library. We have been digitizing these materials to organize Hakodate Digital Archives to publicize them through the internet. In this talk, we look back the first five years of the project. Two distinctive approaches, high-resolution image archiving and collaborative appreciation of collection, are also introduced.
In recent years, various data hiding techniques using Vector Quantization (VQ) have been proposed. However, these methods sometimes could not use optimal output vectors and quality of the output image is thus degraded. In this study, we propose a new data hiding technique using VQ. This method uses tree structures to represent connectivity and distance between output vectors. One node corresponds to an output vector and another one nearest to it are linked by an edge. A suitable vector is chosen for data hiding amongst the output vector itself and its linked vector depending on the embedding information. Simulation results show that our method indicates higher PSNR and SSIM value than the conventional method under the same amounts of embedded data.
To terminate the code of arithmetic coding, redundancy of at most two bits will be caused by flushing the register. If an arithmetic coder can be flushed at every renormalization timing without redundancy, it can be more fast and simple since it does not need to keep the address and the augend of the probability interval. We propose a fast arithmetic coder which produces no redundancy when the coder is flushed, by dividing the final interval into the plural areas corresponding to the combination of necessary succeeding symbols. However, its coding efficiency can be lowered since it allows the mismatch of the probability and the corresponding area of the probability interval. We report the fundamental performance of our proposed arithmetic coder.
In this paper, we propose the content management method using data transition for multiple qualities in video content distributed system. Users freely use the content for multiple qualities, and the elapsed time is used to reduce the unnecessary data in proposed methods. We explain the procedure of data transition, and consider the cases of the improvement of convenience and the low cost. A content use service model is defined, and this is based on elapsed time and used content quality. We consider the efficiency in this model. In prospective conditions of the number of low quality used contents, when they use the content of multiple qualities, if the transition time is set to be long, proposed method is efficient. In addition, when they don’t use the multiple qualities, it cannot be expected to reduce the transmission data. However, there is some advantage of browsing.