• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.1
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• pp.395-413
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• 2016

Image authentication is a technique aiming at protecting the integrity of digital images. Reversible image authentication has attracted much attention of researcher because it allows to authenticate tampered regions in the image and to reconstruct the stego image to its original version losslessly. In this paper, we propose a new, reversible image authentication scheme based on adaptive prediction error expansion (PEE) technique. In the proposed scheme, each image block is classified into smooth or complex regions. Then, according to the characteristic of each block, the authentication code is embedded adaptively to achieve high performance of tamper detection. The experimental results demonstrated that the proposed scheme achieves good quality of stego images. In addition, the proposed scheme has ability to reconstruct the stego image to its original version, if no modification is performed on it. Also demonstrated in the experimental results, the proposed scheme provides higher accuracy of tamper detection than state-of-the-art schemes.

• Journal of the Korea Computer Industry Society
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• v.2 no.3
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• pp.297-308
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• 2001

We propose an algorithm which can reconstruct the 3D information from geographical information. The conventional techniques, the triangular patches and the Random Fractal Midpoint Displacement (RFMD) method, etc., have often been used to reconstruct natural images. While the RFMD method using Gaussian distribution obtains good results for the symmetric images, it is not reliable on asymmetric images immanent in the nature. Our proposed algorithm employs neural networks for the RFMD method to present the asymmetrical images. By using a neural network for reconstructing the 3D images, we can utilize statistical characteristics of irregular data. We show that our algorithm has a better performance than others by the point of view on the similarity evaluation. And, it seems that our method is more efficient for the mountainous topography which is more rough and irregular.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.4
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• pp.679-684
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• 1994

Progressive transmission using optimum bit-ordering of discrete cosine transform(DCT) coded image is proposed to reconstruct a better image in a few bits among all the coded bits at the receiver. It is to transmit the bit gradually to reduce the distrotion of the reconstructed image most by transmitting one more bit. To do this, the power transfer factor(PTF) which is the squared value of difference between the reconstruction level of embedded quantizer and another reconstruction level made by transmitting one more bit is defined. And then, the transmission order of bits is obtained by sorting the PTFs of the coded bits. As a results, the proposed method can reconstruct image having less distortion and better quality at the same bit rate than the conventional zig-zag scan.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.2
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• pp.101-109
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• 1998

In this paper, we implemented holographic optical memory systm which can store and reconstruct many images using new input and angular multiplexing method. In the new input method, phase infomation of input image is inputed in the recording material instead of brightness information. To do so, we represented the images, which captured with CCD camera or displayed on the computer monitor, on the liquid crystal television(LCTV) which removed polarizer/analyzer. Therefore, we can generate uniform input beam intensity regardless of the total brightness of input image, and apply the scheduled recording method. Also we can increase the intensity of input beam so reduce the recording time of input image. And reconstructedimage is acquired by transforming phase information into brightness information of image with analyzer. The incident angle of reference beam is acquired by Fourier transform of the binary phase hologram(BPH) which designed with SA algorithm on the LCTV. The proposed optical memory system is stable because the incident angle of the reference beam is controlled easy and electronically. We demonstreated optical experiment which store and reconstruct various type images in BaTiO$_{3}$ using proposed holographic memory system.

• Journal of the Society of Naval Architects of Korea
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• v.45 no.5
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• pp.477-486
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• 2008

Numerical analysis for slamming impact phenomena has been carried out when 2-dimensional wedge shaped structure with finite deadrise angles enter the free surface by using a commertial CFD code, FLUENT. Fluid is assumed incompressible and entry speed of the structure is kept constant. Geo-reconstruct scheme (or PLIC-VOF scheme) is used for the tracking of the deforming free surface. User defined function of 6 degrees of freedom motion and moving dynamic mesh option are used for the expression of the downward motion of the structure and deforming of unstructured meshes adjacent to the structure. The magnitude and the location of impact pressure and the total drag force which is the summation of pressures distributed at the bottom of the structure are analyzed. Results of the analysis show good agreement with the results of similarity solution, asymptotic solution and the solution of BEM.

• Korean Journal of Head & Neck Oncology
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• v.7 no.2
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• pp.92-98
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• 1991

Numerous mycoutaneous island flaps or free flaps have been used to reconstruct a defect which resulted from the wide resection of tumor mass in head and neck region. Since the curative resection of tumor usually include muscles and bones as well as skin and mucosa, the anatomical and functional restoration of the defect depend on which and what amount of tissues were provided to cover the defect; good aesthetic appearance subsequently follows the result. Furthermore, a simultaneous neck nodes dissection usually results in exposure of major neck vessels., which should be protected with sufficient padding. The ideal method to reconstruct a defect in the head and neck region requires a sufficient coverage by muscle layer with good vascularity, a wide arc of rotation, and minimization of donor site defect. The pectoralis major myocutaneous flap which was first decribed by Ariyan and lateral trapezius myocutaneous flap by Demergasso meet these criteria. We describe the use of these myocutaneous flaps in reconstruction of mandible and oral cavity.

• Korean Journal of Child Studies
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• v.15 no.2
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• pp.97-116
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• 1994

This study investigated the effect of young children's interaction with a teacher and computer environments on their development of representational competence cf replay, the children's ability to construct and reconstruct actions. A pretest-posttest design with one experimental group and one control group was used; quantitative analyses, including interview assessments and coded observations of children's work in the context of educational interventions were supplemented by qualitative analyses of this work. Thirty-nine children (2-5 years of age) were randomly assigned to either an experimental or control group. The educational intervention provided to the experimental group involved a sequence of twenty sessions incorporating a series of three computer environments. A teaching strategy, based on Vygotsky's Zone of Proximal Development (ZPD) and Sigel's distancing theory, was used to mediate children's interaction with these computer environments. Results indicated that children's representational competence kept developing and reached a higher stage and the educational intervention fostered the development of representational competence, with strong evidence of near transfer but no evidence of far transfer. These results suggest that representational competence is a teachable concept and that a complex mediating structure allows children to reconstruct their previous experiences and apply them to problem situations.

• Archives of Craniofacial Surgery
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• v.20 no.6
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• pp.405-407
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• 2019

Due to the variety in the shape of dysmorphic cartilage, tragus reconstruction is one of the most challenging goals in otoplasty. The authors describe a method to reconstruct a prominent tragus in a simple way suitable for accounting for the size, shape, and location of the remaining ear. We present a case of tragus deformity in an 11-year-old female patient after a previous excision of pretragal skin tags. There was a small remnant of the deeply located dystopic cartilage in a horizontal orientation. The dystopic cartilage was used to reconstruct the tragus using a chondrocutaneous transposition flap. Only a small portion of the pre-existing cartilage was used to create a chondrocutaneous transposition flap that supplemented the portion of cartilage during tragus reconstruction. The result was a new tragus that showed acceptable improvement in shape, location, and projection. Patients with a small portion of pre-existing cartilage near the tragal wall may benefit from the use of this method for tragus reconstruction.

• Journal of the Korean Society of Costume
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• v.51 no.8
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• pp.25-41
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• 2001

This Paper reveals the costume culture of early 17th century from the study of private letters found in the tomb of Mrs. JinJoo Ha(\ulcorner - after 1652) excavated in 1989. The tomb was located at KooJi-myon, DalSung-kun, Kyung-Poong Province. Joo Kwak(1569-1617), Mrs. Ha s husband, didn t have a title from the government, but he was a clan in HyunPoong area who had enough land and servants. However, he didn't live togther with mrs. Ha, his second wife, he had to travel between SoRye and NonKong where his wife resided. The 40 or so private letters that contains valuable information that can help us to understand and reconstruct the costume culture of early 17th century in HyunPoong area. We believe that these materials contain somewhat general information that reveals costume of KyungSangDo area even though the materials are from a specific family. By accumulating information from real material like these letters, we also believe that it will give us a better understanding on the costume culture in 17th century, Choson dynasty. Furthermore, it will certainly help us to reconstruct a more realistic lifestyle of the time.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.768-772
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• 2008

Various scanning systems have been studied in many industrial areas to acquire a range data or to reconstruct an explicit 3D model. Currently optical technology has been used widely by virtue of noncontactness and high-accuracy. In this paper, we describe a 3D laser scanning system developped to reconstruct the 3D surface of a large-scale object such as a curved-plate of ship-hull. Our scanning system comprises of 4ch-parallel laser vision modules using a triangulation technique. For multi laser vision, calibration method based on least square technique is applied. In global scanning, an effective method without solving difficulty of matching problem among the scanning results of each camera is presented. Also minimal image processing algorithm and robot-based calibration technique are applied. A prototype had been implemented for testing.