• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.06a
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• pp.102-105
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• 2019

In the classical single-image super-resolution (SISR) reconstruction method using convolutional neural networks, the extracted features are not fully utilized, and the training time is too long. Aiming at the above problems, we proposed an improved SISR method based on a residual network. Our proposed method uses a feature fusion technology based on improved residual blocks. The advantage of this method is the ability to fully and effectively utilize the features extracted from the shallow layers. In addition, we can see that the feature fusion can adaptively preserve the information from current and previous residual blocks and stabilize the training for deeper network. And we use the global residual learning to make network training easier. The experimental results show that the proposed method gets better performance than classic reconstruction methods.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.11
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• pp.4463-4482
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• 2020

Mesh model generated from 3D reconstruction usually comes with lots of noise, which challenges the performance and robustness of mesh simplification approaches. To overcome this problem, we present a novel method for mesh simplification which could preserve structure and improve the accuracy. Our algorithm considers both the planar structures and linear features. In the preprocessing step, it automatically detects a set of planar structures through an iterative diffusion approach based on Region Seed Growing algorithm; then robust linear features of the mesh model are extracted by exploiting image information and planar structures jointly; finally we simplify the mesh model with plane constraint QEM and linear feature preserving strategies. The proposed method can overcome the known problem that current simplification methods usually degrade the structural characteristics, especially when the decimation is extreme. Our experimental results demonstrate that the proposed method, compared to other simplification algorithms, can effectively improve the quality of mesh and yield an increased robustness on noisy input mesh.

• Current Optics and Photonics
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• v.6 no.1
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• pp.1-9
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• 2022

This paper proposes a robust, simple zonal wavefront-estimation method in a grid sampling model. More slopes are added to the integral equation of the algorithm to improve the accuracy and convergence rate of this approach, especially for higher-order optical aberrations. The Taylor theorem is applied to clarify the mathematical description of the remaining error in the proposed method. Several numerical simulations are conducted to ensure the performance and improvement in comparison to the Southwell and previous algorithm. An experiment is also conducted according to deflectometry output and the results are verified using a reference measured with a stylus system.

• Current Optics and Photonics
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• v.5 no.6
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• pp.680-685
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• 2021

We propose a technique that reconstructs a hologram whose pixel number is greater than the pixel numbers of a conventional image sensor. The pixel numbers of the hologram recorded by optical scanning holography (OSH) increases as the scan area becomes larger. The reconstruction time also increases drastically as the size of the hologram increases. The holographic information of a three-dimensional (3D) scene is distributed throughout the recorded hologram; this makes the simple divide-and-stitch approach fail. We propose a technique that reconstructs the hologram without loss of holographic information. First, we record the hologram of a 3D scene using OSH. Second, we segment the hologram into sub-holograms that contain complete holographic information. Third, we reconstruct the sub-holograms simultaneously. Finally, we rearrange the reconstructions of the sub-holograms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.1
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• pp.321-340
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• 2016

The Compressive Video Sensing (CVS) is a useful technology for wireless systems requiring simple encoders but handling more complex decoders, and its rate-distortion performance is highly affected by the quantization of measurements and reconstruction of video frame, which motivates us to presents the Space-Time Quantization (ST-Q) and Motion-Aligned Reconstruction (MA-R) in this paper to both improve the performance of CVS system. The ST-Q removes the space-time redundancy in the measurement vector to reduce the amount of bits required to encode the video frame, and it also guarantees a low quantization error due to the fact that the high frequency of small values close to zero in the predictive residuals limits the intensity of quantizing noise. The MA-R constructs the Multi-Hypothesis (MH) matrix by selecting the temporal neighbors along the motion trajectory of current to-be-reconstructed block to improve the accuracy of prediction, and besides it reduces the computational complexity of motion estimation by the extraction of static area and 3-D Recursive Search (3DRS). Extensive experiments validate that the significant improvements is achieved by ST-Q in the rate-distortion as compared with the existing quantization methods, and the MA-R improves both the objective and the subjective quality of the reconstructed video frame. Combined with ST-Q and MA-R, the CVS system obtains a significant rate-distortion performance gain when compared with the existing CS-based video codecs.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.7 s.337
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• pp.21-26
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• 2005

An area efficient, low power switch-matrix semidigital FIR reconstruction filter for delta-sigma D/A converter is proposed. Filter coefficients are quantified to 7-bit and 7 current sources that correspond to each coefficient bit are used. The proposed semidigital FIR reconstruction filter is designed in a 0.25 um CMOS process and incorporates 1.5 mm$^{2}$ of active area and a power consumption is 3.8 mW at 2.5 V supply. The number of switching transistors is 1419 at 205 filter order. Simulation results show that the filter output has a dynamic range of 104 dB and 84 dB attenuation of out-of-band quantization noise.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2000.11a
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• pp.56-58
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• 2000

Post-genomics may be defined in different ways depending on how one views the challenges after the genome. A popular view is to follow the concept of the central dogma in molecular biology, namely from genome to transcriptome to proteome. Projects are going on to analyze gene expression profiles both at the mRNA and protein levels and to catalog protein 3D structure families, which will no doubt help the understanding of information in the genome. However complete, such catalogs of genes, RNAs, and proteins only tell us about the building blocks of life. They do not tell us much about the wiring (interaction) of building blocks, which is essential for uncovering systemic functional behaviors of the cell or the organism. Thus, an alternative view of post-genomics is to go up from the molecular level to the cellular level, and to understand, what I call, the "interactome"or a complete picture of molecular interactions in the cell. KEGG (http://www.genome.ad.jp/kegg/) is our attempt to computerize current knowledge on various cellular processes as a collection of "generalized"protein-protein interaction networks, to develop new graph-based algorithms for predicting such networks from the genome information, and to actually reconstruct the interactomes for all the completely sequenced genomes and some partial genomes. During the reconstruction process, it becomes readily apparent that certain pathways and molecular complexes are present or absent in each organism, indicating modular structures of the interactome. In addition, the reconstruction uncovers missing components in an otherwise complete pathway or complex, which may result from misannotation of the genome or misrepresentation of the KEGG pathway. When combined with additional experimental data on protein-protein interactions, such as by yeast two-hybrid systems, the reconstruction possibly uncovers unknown partners for a particular pathway or complex. Thus, the reconstruction is tightly coupled with the annotation of individual genes, which is maintained in the GENES database in KEGG. We are also trying to expand our literature surrey to include in the GENES database most up-to-date information about gene functions.

• Journal of the Korean Arthroscopy Society
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• v.1 no.1
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• pp.132-138
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• 1997

The purpose of this study is to compare the results between conventional and accelerated rehabilitation program following ACL reconstruction using bone-patellar tendon-bone. Conventional rehabilitation focused on protecting the new ligament by blocking terminal extension and avoiding active quadriceps function in the terminal degrees of extension. But there is current trend toward early postoperative mobilization and intensive. so called 'accelerated', rehabilitation stressing hyperextension of the knee. The results of intraarticular ACL reconstruction with conventional and accelerated rehabilitation were prospectively compared for one year postoperatively in a series of 27 patients. Range of motion and thigh circumference were checked preoperatively, and weekly up to 8 weeks, 3 months. 6 months, and 1 year postoperatively. Stress radiologic test, KT-1000 arthrometer. Cybex II dynamometer were checked in preoperatively, and 3 months, 6 months, and 1 year postoperatively. There were no differences of objective stability and restoration of muscle power. But the accelerated group had a low incidence of extension loss. excellent range of motion, and less difference of thigh circumference. We concluded that accelerated rehabilitation program is recommendable due to superiority in terms of range of motion, especially less extension loss without increasing laxity of knee joint.

• Archives of Plastic Surgery
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• v.46 no.1
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• pp.7-15
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• 2019

Breast animation deformity (BAD) has been reported to occur after submuscular implant placement following breast augmentation and immediate breast reconstruction. Despite its apparent impact on patients' quality of life, BAD has only recently become a topic of general concern. Its incidence and etiology have yet to be established. The aim of this systematic review was to identify papers that clearly defined and classified BAD and described how the degree of animation was assessed. We performed a search in PubMed and Embase. Studies meeting the inclusion criteria that described BAD after implant-based breast augmentation or immediate breast reconstruction were included. After screening 866 publications, four studies were included: three describing BAD after breast augmentation and one describing BAD after immediate breast reconstruction. The median percentage of patients with some degree of BAD was 58%. The highest percentages were found in patients operated on using the Regnault technique or the dual-plane technique (73%-78%). The lowest percentages were found following the dual-plane muscle-splitting technique (30%) and the triple-plane technique (33%). We found no studies meeting the inclusion criteria that analyzed BAD after prepectoral implant placement. This review of the current literature suggests that the degree of BAD is proportional to the degree of muscle involvement. Evidence is scarce, and the phenomenon seems to be underreported. Future comparative studies are warranted.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.2
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• pp.112-119
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• 2021

Objectives: Myxomatous odontogenic tumors (MOTs) are the third most common odontogenic tumors in the oral and maxillofacial region. Due to its slow-growing, but locally invasive nature, the tumor is usually detected by accident or only when it becomes a large mass, which causes facial deformity. Materials and Methods: Current study reports three unusual cases of MOT including huge myxoma involve the mandible in middle-aged man, MOT with ossifying fibroma pattern in mandible, and MOT in maxilla of young female patient. The diagnosis and treatment strategy of MOTs was also summarized and updated. Results: In reported three cases of patients with large MOTs, surgical treatment was indicated with fibular free flap reconstruction in the mandible and plate reconstruction in the maxilla. The tumors were successfully treated with radical resection and did not show signs of recurrence during the follow-up period. Conclusion: Surgical treatment indication depends on size, the position of the lesion, patient systemic condition and surgeon individual experience. In the case of a large tumor, radical resection and reconstruction is the standard surgical strategy. The conservative surgical treatment including enucleation with wide curettage is still under controversy. The recurrence rate for MOTs is significantly high, up to 30%, therefore long-term follow-up is essential.