In-Kwon Lee
Yonsei University
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Publication
Featured researches published by In-Kwon Lee.
Gene Therapy | 2002
J D Ahn; Ryuichi Morishita; Yasufumi Kaneda; Hyun-Kyung Kim; Young-Chae Chang; Kang-Woo Lee; Joong Yeol Park; Lee Hw; Yang-Hyun Kim; In-Kwon Lee
The transcription factor, E2F, plays a critical role in the trans-activation of several genes involved in cell cycle regulation. Previous studies showed that the transfection of cis element double-stranded decoy oligodeoxynucleotides (ODNs) corresponding to E2F binding sites inhibited the proliferation of vascular smooth muscle cells (VSMCs) and neointimal hyperplasia in injured vessels. We have developed a novel E2F decoy ODN with a circular dumbbell structure (CD-E2F) and compared its effects with those of the conventional phosphorothioated E2F decoy (PS-E2F) ODN. CD-E2F ODN was more stable than PS-E2F ODN, largely preserving its structural integrity after incubation in the presence of nucleases and sera. Moreover, CD-E2F ODN inhibited high glucose- and serum-induced transcriptional expression of cell cycle regulatory genes more strongly than PS-E2F ODN. Transfection of CD-E2F ODN resulted in more effective inhibition of VSMC proliferation in vitro and neointimal formation in vivo, compared with PS-E2F ODN. An approximately 40–50% lower dose of CD-E2F ODN than PS-E2F ODN was sufficient to attain similar effects. In conclusion, our results indicate that CD-E2F ODN may be a valuable tool in gene therapy protocols for inhibiting VSMC proliferation and studying transcriptional regulation.
Computer Graphics Forum | 2005
Hyun Chul Lee; In-Kwon Lee
We synchronize background music with an animation by changing the timing of both, an approach which minimizes the damage to either. Starting from a MIDI le and motion data, feature points are extracted from both sources, paired, and then synchronized using dynamic programming to time-scale the music and to timewarp the motion. We also introduce the music graph, a directed graph which encapsulates connections between many short music sequences. By traversing a music graph we can generate large amounts of new background music, in which we expect to nd a sequence which matches the motion better than the original music.
Signal Processing | 2016
Xiao-Wei Li; Chengqing Li; In-Kwon Lee
Integral imaging-based cryptographic algorithms provide a new way to design secure and robust image encryption systems. In this paper, we introduce a performance-enhanced image encryption scheme based on depth-conversion integral imaging and hybrid cellular automata (CA), aiming to meet the requirements of secure image transmission. First, the input image is decomposed into an elemental image array (EIA) using the depth-converted integral imaging technique. The obtained elemental images then are encrypted by utilizing the CA model and chaotic sequence. The conventional computational integral imaging reconstruction (CIIR) technique is a pixel-superposition technique. The resolution of the reconstructed image is dramatically degraded by the large magnification factor in the superposition process as the pickup distance increases. In the proposed reconstruction process, the pixel mapping technique is introduced to solve these problems. A novel property of the proposed scheme is its depth-conversion property, which reconstructs an elemental image originally recorded at long distances from the pinhole array as one that was recorded near the pinhole array and consequently reduces the magnification factor. The results of numerical simulations demonstrate the effectiveness and security of the proposed scheme. HighlightsChaotic image encryption based on the pixel mapping method.Proposed method improves robustness against data loss attacks.Cellular automata provides high-key space encryption algorithm.
Optics Express | 2015
Xiao-Wei Li; In-Kwon Lee
Generally, conventional transform (DWT and DFT, etc.) -based watermarking techniques provide only one spectrum plane for embedding the watermark, thus the embedding watermark information can be easily removed. To solve this problem, we propose an efficient cellular automata (CA) based watermarking method that CA transform (CAT) with various gateway values can provide many transform planes for watermark embedding according to various CA rules. In this paper, multiple ownership watermarks are first recorded in the form of an elemental image array (EIA), simultaneously, and then the recorded EIA as the watermark data is embedded into the CAT coefficient. An additional advantage of this proposed method is that EIA is composed of many elemental images and each elemental image has its own property of watermarks. Even though most data of elemental images are lost, the watermarks can be reconstructed from the remaining elemental images successfully. Experimental results show that the proposed technique provides good image quality and is robust in varying degree to some image processing attacks.
Multimedia Tools and Applications | 2009
Jong-Chul Yoon; In-Kwon Lee; Siwoo Byun
We show how to create a music video automatically, using computable characteristics of the video and music to promote coherent matching. We analyze the flow of both music and video, and then segment them into sequences of near-uniform flow. We extract features from the both video and music segments, and then find matching pairs. The granularity of the matching process can be adapted by extending the segmentation process to several levels. Our approach drastically reduces the skill required to make simple music videos.
The Visual Computer | 2008
Ji-yong Kwon; In-Kwon Lee
We propose a method to determine camera parameters for character motion, which considers the motion by itself. The basic idea is to approximately compute the area swept by the motion of the character’s links that are orthogonally projected onto the image plane, which we call “motion area”. Using the motion area, we can determine good fixed camera parameters and camera paths for a given character motion in the off-line or real-time camera control. In our experimental results, we demonstrate that our camera path generation algorithms can compute a smooth moving camera path while the camera effectively displays the dynamic features of character motion. Our methods can be easily used in combination with the method for generating occlusion-free camera paths. We expect that our methods can also be utilized by the general camera planning method as one of heuristics for measuring the visual quality of the scenes that include dynamically moving characters.
The Visual Computer | 2008
Won-Seob Jang; Won-Kyu Lee; In-Kwon Lee; Jehee Lee
We have synthesized new human body motions from existing motion data, by dividing the body of an animated character into several parts, such as upper and lower body, and partitioning the motion of the character into corresponding partial motions. By combining different partial motions, we can generate new motion sequences. We select the most natural-looking combinations by analyzing the similarity of partial motions, using techniques such as motion segmentation, dimensionality reduction, and clustering. These new combinations can dramatically increase the size of a motion database, allowing more score in selecting motions to meet constraints, such as collision avoidance. We verify the naturalness and physical plausibility of the new motions using an SVM learning model and by analysis of static and dynamic balance.
Computer Graphics Forum | 2008
Jong-Chul Yoon; In-Kwon Lee; Henry Kang
A hidden‐picture puzzle contains objects hidden in a background image, in such a way that each object fits closely into a local region of the background. Our system converts image of the background and objects into line drawing, and then finds places in which to hide transformed versions of the objects using rotation‐invariant shape context matching. During the hiding process, each object is subjected to a slight deformation to enhance its similarity to the background. The results were assessed by a panel of puzzle‐solvers.
computer graphics international | 2006
Jong-Hyuk Kim; Jung-Ju Choi; Hyun Joon Shin; In-Kwon Lee
According to the principles of traditional 2D animation techniques, anticipation makes an animation convincing and expressive. In this paper, we present a method to generate anticipation effects for an existing animation. The proposed method is based on the visual characteristics of anticipation, that is, “Before we go one way, first we go the other way[1].” We first analyze the rotation of each joint and the movement of the center of mass during a given action, where the anticipation effects are added. Reversing the directions of rotation and translation, we can obtain an initially guessed anticipatory pose. By means of a nonlinear optimization technique, we can obtain a consequent anticipatory pose to place the center of mass at a proper location. Finally, we can generate the anticipation effects by compositing the anticipatory pose with a given action, while considering the continuity at junction and preserving the high frequency components of the given action. Experimental results show that the proposed method can produce the anticipatory pose successfully and quickly, and generate convincing and expressive anticipation effects.
Gene Therapy | 2006
Yeon-Yong Kim; Park Kg; Ryuichi Morishita; Yasufumi Kaneda; Sunyoung Kim; Song Dk; Hyun-Kyung Kim; Chung-Mo Nam; Hyun Chul Lee; Kang-Woo Lee; Joong Yeol Park; Kim Bw; Kim Jg; In-Kwon Lee
Insulin gene therapy in clinical medicine is currently hampered by the inability to regulate insulin secretion in a physiological manner, the inefficiency with which the gene is delivered, and the short duration of gene expression. To address these issues, we injected the liver of streptozotocin-induced diabetic rats with hemagglutinating virus of Japan-envelope (HVJ-E) vectors containing Epstein–Barr virus (EBV) plasmids encoding the genes for insulin and the GLUT 2 transporter. Efficient delivery of the genes was achieved with the HVJ-E vector, and the use of the EBV replicon vector led to prolonged hepatic gene expression. Blood glucose levels were normalized for at least 3 weeks as a result of the gene therapy. Cotransfection of GLUT 2 with insulin permitted the diabetic rats to regulate their blood glucose levels upon exogenous glucose loading in a physiologically appropriate manner and improved postprandial glucose levels. Moreover, cotransfection with insulin and GLUT 2 genes led to in vitro glucose-stimulated insulin secretion that involved the closure of KATP channels. The present study represents a new way to efficiently deliver insulin gene in vivo that is regulated by ambient glucose level with prolonged gene expression. This may provide a basis to overcome limitations of insulin gene therapy in humans.