• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.5 s.305
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• pp.1-10
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• 2005

Content-based image retrieval systems are being actively investigated owing to their ability to retrieve images based on the actual visual content rather than by manually associated textual descriptions. In this paper, we propose a novel approach for image retrieval based on edge structural features using edge correlogram and color coherence vector. After color vector angle is applied in the pre-processing stage, an image is divided into two image parts (high frequency image and low frequency image). In low frequency image, the global color distribution of smooth pixels is extracted by color coherence vector, thereby incorporating spatial information into the proposed color descriptor. Meanwhile, in high frequency image, the distribution of the gray pairs at an edge is extracted by edge correlogram. Since the proposed algorithm includes the spatial and edge information between colors, it can robustly reduce the effect of the significant change in appearance and shape in image analysis. The proposed method provides a simple and flexible description for the image with complex scene in terms of structural features of the image contents. Experimental evidence suggests that our algorithm outperforms the recently histogram refinement methods for image indexing and retrieval. To index the multidimensional feature vectors, we use R*-tree structure.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.6
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• pp.79-84
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• 2015

In a distribution of digital image, there is a serious problem that is a distribution of the altered image by a forger. For the problem solution, this paper proposes a median filtering (MF) image forensic decision algorithm using a feature vector according to the pixel value's gradients. In the proposed algorithm, AR (Autoregressive) coefficients are computed from pixel value' gradients of original image then 1th~6th order coefficients to be six feature vector. And the reconstructed image is produced by the solution of Poisson's equation with the gradients. From the difference image between original and its reconstructed image, four feature vector (Average value, Max. value and the coordinate i,j of Max. value) is extracted. Subsequently, Two kinds of the feature vector combined to 10 Dim. feature vector that is used in the learning of a SVM (Support Vector Machine) classification for MF (Median Filtering) detector of the altered image. On the proposed algorithm of the median filtering detection, compare to MFR (Median Filter Residual) scheme that had the same 10 Dim. feature vectors, the performance is excellent at Unaltered, Averaging filtering ($3{\times}3$) and JPEG (QF=90) images, and less at Gaussian filtering ($3{\times}3$) image. However, in the measured performances of all items, AUC (Area Under Curve) by the sensitivity and 1-specificity is approached to 1. Thus, it is confirmed that the grade evaluation of the proposed algorithm is 'Excellent (A)'.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.2
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• pp.149-156
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• 2012

Support vector machines (SVMs) are well known for their pattern recognition capability, but proper care should be taken to alleviate their inherent implementation cost resulting from high computational intensity and memory requirement, especially in embedded systems where only limited resources are available. Since the memory requirement determined by the dimensionality and the number of support vectors is generally too high for a cache in embedded systems to accomodate, frequent accesses to the main memory occur inevitably whenever the cache is not able to provide requested data to the processor. These frequent accesses to the main memory result in overall performance degradation and increased energy consumption because a memory access typically takes longer and consumes more energy than a cache access or a register access. In this paper, we propose a technique that reduces the number of main memory accesses by optimizing the data access pattern of the SVM-based classifier in such a way that the temporal locality of the accesses increases, fully utilizing data loaded into the processor chip. With experiments, we confirm the enhancement made by the proposed technique in terms of the number of memory accesses, overall execution time, and energy consumption.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.6
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• pp.102-111
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• 2009

In this paper, we propose a de-interlacing algorithm that combines a motion compensation (MC) method and the vertical-temporal filter with motion compensation (MC V-T filter) according to motion compensation reliability. The MC method represent one of the best ways of improving the resolution of de-interlaced frames, but it may introduce motion compensation artifacts in regions with incorrect motion information. In these regions, the MC V-T filter that is very robust to motion vector errors can be used to correct motion compensation artifacts. The combination between two methods is controlled by the motion compensation reliability that is measured by analyzing the estimated motion vectors and the results of MC. The motion compensation reliability contains information about motion compensation artifacts of MC results and determines the combination weight according to this information. Therefore, the combination rule of the proposed method is more accurate than those of the conventional methods and it enables the proposed method to provide high quality video sequences without producing any visible artifacts. Experimental results with various test sequences show that the proposed algorithm outperforms conventional algorithms in terms of both visual and numerical criteria.

• Journal of the Korea Concrete Institute
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• v.24 no.2
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• pp.205-214
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• 2012

Crack widths play an important role in the serviceability limit state. When crack widths are controlled sufficiently, the reinforcement corrosion can be reduced using only existing concrete cover thickness due to low permeability in the region of finely distributed hair-cracks. Thus, the knowledge about the tensile crack opening is essential in designing more durable concrete structures. Therefore, numerous researches related to the topic have been performed. Nevertheless accurate measurement of a crack width is not a simple task due to several reasons such as unknown potential crack formation location and crack opening damaging strain gages. In order to overcome these difficulties and measure precise crack widths, a displacement measurement system was developed using digital image correlation. Accuracy calibration tests gave an average measurement error of 0.069 pixels and a standard deviation of 0.050 pixels. Direct tensile test was performed using ultra high performance concrete specimens. Crack widths at both notched and unnotched locations were measured and compared with clip-in gages at various loading steps to obtain crack opening profile. Tensile deformation characteristics of concrete were well visualized using displacement vectors and full-field displacement contour maps. The proposed technique made it possible to measure crack widths at arbitrary locations, which is difficult with conventional gages such as clip-in gages or displacement transducers.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.2
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• pp.319-326
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• 2020

PRNGs(Pseudorandom number generators) are essential for generating encryption keys for to secure online communication. A bitstream generated by the PRNG must be generated at high speed to encrypt the big data effectively in a symmetric key cryptosystem and should ensure the randomness of the level to pass through the several statistical tests. CA(Cellular Automata) based PRNGs are known to be easy to implement in hardware and to have better randomness than LFSR based PRNGs. In this paper, we design PRNGs based on PMLCA(Programable Maximum Length CA) that can generate effective key sequences in symmetric key cryptosystem. The proposed PRNGs generate bit streams through nonlinear control method. First, we design a PRNG based on an (m,n)-cell PMLCA ℙ with a single complement vector that produces linear sequences with the long period and analyze the period and the generating polynomial of ℙ. Next, we design an (m,n)-cell PC-MLCA based PRNG with two complement vectors that have the same period as ℙ and generate nonlinear sequences, and analyze the location of outputting the nonlinear sequence.

• International Journal of Oral Biology
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• v.34 no.1
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• pp.21-28
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• 2009

Mutations in DLX3 are associated with both autosomal dominant hypoplastic hypomaturation amelogenesis imperfecta (ADHHAI) and tricho-dento-osseous (TDO) syndrome. ADHHAI is caused by a c.561_562delCT (2bp-del DLX3) mutation whereas TDO syndrome is associated with a c.571_574delGGGG (4bp-del DLX3) mutation. However, although the causal relationships between DLX3 and an enamel phenotype have been established, the pathophysiological role of DLX3 mutations in enamel development has not yet been clarified. In our current study, we prepared expression vectors for wild type and deletion mutant DLX3 products (4bp-del DLX3, 2bp-del DLX3) and examined the effects of their overexpression on the expression of the enamel matrix proteins and proteases. Wild type DLX3 enhanced the expression of matrix metalloprotease 20 (MMP20) mRNA and protein in murine ameloblast-like cells. However, neither a 4bp-del nor 2bp-del DLX3 increased MMP20 expression. Wild type DLX3, but not the above DLX3 mutants, also increased the activity of reporters containing 1.5 kb or 0.5 kb of the MMP20 promoter. An examination of protein stability showed that the half-life of wild type DLX3 protein was less than 12 h whilst that of both deletion mutants was longer than 24 h. Endogenous Dlx3 was also found to be continuously expressed during ameloblast differentiation. Since inactivating mutations in the gene encoding MMP20 are associated with amelogenesis imperfecta, the inability of 4bp-del or 2bp-del DLX3 to induce MMP20 expression suggests a possible involvement of such mutations in the enamel phenotype associated with TDO syndrome or ADHHAI.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.4 s.310
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• pp.37-45
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• 2006

In this paper, we propose the development of MHLA(Modulatory Hippocampus Learning Algorithm) which remodel a principle of brain of hippocampus. Hippocampus takes charge auto-associative memory and controlling functions of long-term or short-term memory strengthening. We organize auto-associative memory based 3 steps system(DG, CA3, CAl) and improve speed of learning by addition of modulator to long-term memory learning. In hippocampal system, according to the 3 steps order, information applies statistical deviation on Dentate Gyrus region and is labelled to responsive pattern by adjustment of a good impression. In CA3 region, pattern is reorganized by auto-associative memory. In CAI region, convergence of connection weight which is used long-term memory is learned fast by neural networks which is applied modulator. To measure performance of MHLA, PCA(Principal Component Analysis) is applied to face images which are classified by pose, expression and picture quality. Next, we calculate feature vectors and learn by MHLA. Finally, we confirm cognitive rate. The results of experiments, we can compare a proposed method of other methods, and we can confirm that the proposed method is superior to the existing method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.6B
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• pp.930-939
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• 2010

Recently, many researches for making more comfortable input device based on gaze detection have been vigorously performed in human computer interaction. However, these previous researches are difficult to be used in IPTV environment because these methods need additional wearing devices or do not work at a distance. To overcome these problems, we propose a new way of controlling IPTV interface by using a detected face and eye positions in single static camera. And although face or eyes are not detected successfully by using Adaboost algorithm, we can control IPTV interface by using motion vectors calculated by pyramidal KLT (Kanade-Lucas-Tomasi) feature tracker. These are two novelties of our research compared to previous works. This research has following advantages. Different from previous research, the proposed method can be used at a distance about 2m. Since the proposed method does not require a user to wear additional equipments, there is no limitation of face movement and it has high convenience. Experimental results showed that the proposed method could be operated at real-time speed of 15 frames per second. Wd confirmed that the previous input device could be sufficiently replaced by the proposed method.

• The Journal of the Acoustical Society of Korea
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• v.33 no.2
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• pp.118-125
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• 2014

An approximation of speed of sound in the measurement plane is essential for the inverse estimation of temperature. To this end, an inverse problem relating the measured retarded time data in between set of sensors and actuators array located on the wall is formulated. The involved transfer matrix and its coefficient vectors approximate speed of sound of the measurement plane by using the radial basis function with finite number of interpolation points deployed inside the target field. Then, the temperature field can be reconstructed by using spatial interpolation technique, which can achieve high spatial resolution with proper number of interpolation points. A large number of retarded time data of acoustic paths in between sensors and arrays are needed to obtain accurate reconstruction result. However, the shortage of interpolation points due to practical limitations can cause the decrease of spatial resolution and deterioration of the reconstruction result. In this works, a regeneration for obtaining the additional retarded time data for an arbitrary acoustic path is suggested to overcome the shortage of interpolation points. By applying the regeneration technique, many interpolation points can be deployed inside the field by increasing the number of retarded time data. As a simulation example, two rectangular duct sections having arbitrary temperature distribution are reconstructed by two different data set: measured data only, combination of measured and regenerated data. The result shows a decrease in reconstruction error by 15 % by combining the original and regenerated retarded time data.