Pocheon, South Korea
Pocheon, South Korea

Daejin University is a private university in Pocheon City, Gyeonggi province of South Korea. About 200 instructors are employed. The current president is Chung, Tae Soo, who has served since the university's founding.The university operates Daejin University China Campus, a study abroad program based at the campuses of two universities in the People's Republic of China: Soochow University in Suzhou, and Harbin Normal University in Harbin. Wikipedia.


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Patent
Waygence Co. and Daejin University | Date: 2016-04-19

According to the present invention, ultrasonic image quality can be improved by removing side lobe signals using a nonlinear filter that subtracts the side lobe signals calculated from a summed signal resulting from the received channel signals obtained by focusing signals received via an array transducer having a plurality of receiving elements and uses the calculated magnitude of the side lobe signals as a filter coefficient. The present invention includes an array transducer to receive an ultrasonic signal reflected from an imaging point and to output the reflected ultrasonic signal as a channel signal of a corresponding receiving element, a focusing delay module to temporally align the channel signals of the receiving elements, a summation unit to sum the temporally aligned channel signals and output the summed signal in order to form an ultrasonic image, a side lobe computation module to calculate a waveform of a side lobe signal generated due to a leakage of the ultrasonic signal, and a filter unit to filter the summed signal of the summation unit based on the magnitude of the side lobe signal computed by the side lobe computation module in order to improve ultrasonic image quality.


Patent
Waygence Co., Hallym University and Daejin University | Date: 2014-04-30

Disclosed are a module for processing an ultrasonic signal based on spatial coherence and a method for processing an ultrasonic signal, and more particularly, to a module for processing an ultrasonic signal based on spatial coherence and a method for processing an ultrasonic signal that is configured to obtain an enhanced ultrasonic image by processing a reflected ultrasonic signal based on characteristics of a reflector or a medium. A module for processing an ultrasonic signal receives an ultrasonic signal reflected from the inside of a human body and forms an image based on the ultrasonic signal.


An effective method for the 3D porous scaffold design of human tissue is presented based on a hybrid method of distance field and triply periodic minimal surface (TPMS). By the creative application of traditional distance field algorithm into the Boolean operations of the anatomical model and TPMS-based unit cell library, an almost defects free porous scaffolds having the complicated micro-structure and high quality external surface faithful to a specific anatomic model can be easily obtained without the difficult and time-consuming trimming and re-meshing processes. After generating the distance fields for the given tissue model and required internal micro-structure, a series of simple modifications in distance fields enable us to obtain a complex porous scaffold. Experimental results show that the proposed scaffold design method has the potential to combine the perfectly interconnected pore networks based on the TPMS unit cell libraries and the given external geometry in a consistent framework irrespective of the complexity of the models. © 2011 Elsevier Ltd.


Yoo D.,Daejin University
Materials Science and Engineering C | Year: 2013

This paper presented an effective method for the three-dimensional (3D) hierarchical porous scaffold design for tissue engineering. To achieve such a hierarchical porous structure with accurately controlled internal pore architectures, the recursive intersection Boolean operation (RIBO) was proposed in order to satisfy computational efficiency and biological function requirements of a porous scaffold. After generating the distance field (DF) for the given anatomic model and required pore architectures, the recursive DF modifications enable us to design hierarchical porous scaffolds with complex combinations of pore morphologies. A variety of experimental results showed that the proposed hierarchical porous scaffold design method has the potential benefits for accurately controlling both the porosity and the pore architecture gradients while preserving the advantages of triply periodic minimal surface pore geometries. © 2013 Elsevier B.V. All Rights Reserved.


Yoo D.-J.,Daejin University
CAD Computer Aided Design | Year: 2011

An effective method for the 3D Bio-CAD model reconstruction of human bone from a scanned point cloud data or a sequence of CT image data is presented based on a B-spline interpolation scheme. In the method, a base surface is generated by creating a smooth implicit surface from the given point cloud data or a sequence of CT image data. The implicit surface is defined by a combination of the well-known thin plate radial basis functions (RBFs) using the domain decomposition method (DDM). After generating the base implicit surface, various types of CAD models such as surface and solid are constructed by using the base implicit surface. In order to reconstruct a complex model, voxel data which can be extracted easily from the base implicit surface are used to generate a rectangular curve net with good quality using the projection and smoothing scheme. After generating the interior points and tangential vectors in each rectangular region considering the required accuracy, a complex B-spline surface is reconstructed by interpolating the rectangular array of points. Experimental results show that the proposed method creates the three dimensional shapes of human bones suitable for bone scaffold design, finite element analysis, and medical diagnosis. © 2011 Elsevier Ltd. All rights reserved.


Yoo D.,Daejin University
Medical Engineering and Physics | Year: 2012

This paper presented an effective method for the 3D heterogeneous porous scaffold design of human tissue using triply periodic minimal surface (TPMS) internal pore architectures. First, an implicit solid representing the smooth 3D scalar field for the porosity distribution was reconstructed by interpolating the geometric positions of control points and porosity values defined at those points using an implicit interpolation algorithm based on the thin-plate radial basis function. After generating the implicit solid representing the smooth 3D scalar field for the porosity distribution, a functionally graded tissue scaffold with accurately controlled porosity distribution was designed using the TPMS-based unit cell libraries. Numerical results showed that the proposed scaffold design method has the potential benefits for accurately controlling the spatial porosity distribution within an arbitrarily shaped scaffold while keeping the advantage of the TPMS-based unit cell libraries. © 2012 IPEM.


Yoo D.-J.,Daejin University
International Journal of Precision Engineering and Manufacturing | Year: 2011

Recently, computer aided geometric design of triply periodic minimal surfaces (TPMS) has received considerable attention in the area of computer aided nano design on account of its ability to efficiently construct a large number of complex surfaces. In this paper, a TPMS is described with periodic surfaces composed of simple trigonometric functions, thus enabling easy generation of TPMS for use in various mechanical, chemical, and physical applications. We first describe a TPMS with mesh surface using conventional marching cube algorithm. We then propose various related algorithms for generating complete solid model for various applications, ranging from thickened solid, through voxel solid, to complexshaped solid. The validity of this new technique is demonstrated for a variety of TPMSs, including the P, G, D, I-WP, F-RD, L, and I2-Y** surfaces. Finally, a new control approach for pore size distribution in tissue scaffold design is presented based on the pore-making element composed of TPMS and conformal refinement of all-hexahedral mesh in order to show the practical applicability of the newly suggested modeling approach. © KSPE and Springer 2011.


Advanced additive manufacture (AM) techniques are now being developed to fabricate scaffolds with controlled internal pore architectures in the field of tissue engineering. In general, these techniques use a hybrid method which combines computer-aided design (CAD) with computer-aided manufacturing (CAM) tools to design and fabricate complicated three-dimensional (3D) scaffold models. The mathematical descriptions of micro-architectures along with the macro-structures of the 3D scaffold models are limited by current CAD technologies as well as by the difficulty of transferring the designed digital models to standard formats for fabrication. To overcome these difficulties, we have developed an efficient internal pore architecture design system based on triply periodic minimal surface (TPMS) unit cell libraries and associated computational methods to assemble TPMS unit cells into an entire scaffold model. In addition, we have developed a process planning technique based on TPMS internal architecture pattern of unit cells to generate tool paths for freeform fabrication of tissue engineering porous scaffolds. © 2012 IPEM.


Disclosed is a nanoparticle generating unit, a nanoparticle coating unit, and a core-shell nanoparticle collecting unit are connected to link and continuously process generation of nanoparticles and a coating and collecting process. The nanoparticle coating unit is formed of a porous material or in a grid structure and a moving speed of the nanoparticles can be decreased using a speed adjustment member installed at a process passage of a coating chamber.


Disclosed is a coating chamber having a process passage in which a coating process is performed, a particle supply means configured to supply nanoparticles into the process passage, a gas supply means configured to supply a carrier gas and a reactive gas serving as a source of a shell material into the process passage, and a low pressure forming means configured to form a low pressure in the process passage. The coating chamber has a speed adjustment member formed of a porous material or a grid and installed in the process passage, and as a moving speed of the nanoparticles is decreased due to flow resistance or collision of the nanoparticles passing through the speed adjustment member, first and second precursors supplied as the reactive gas move more rapidly than the nanoparticles to coat a thin film on the nanoparticles with the material.

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