• Journal of the Korea Society of Computer and Information
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• v.19 no.1
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• pp.23-30
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• 2014

Feature matching using image descriptors is robust method used recently. However, mismatches occur in 3D transformed images, illumination-changed images and repetitive-pattern images. In this paper, we observe that there are a lot of mismatches in the images which have repetitive patterns. We analyze it and propose a method to eliminate these mismatches. MDMF(Multiple Descriptors-based Mismatch Filtering) eliminates mismatches by using descriptors of nearest several features of one specific feature point. In experiments, for geometrical transformation like scale, rotation, affine, we compare the match ratio among SIFT, ASIFT and MDMF, and we show that MDMF can eliminate mismatches successfully.

• ETRI Journal
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• v.34 no.5
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• pp.734-742
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• 2012

A novel interaction method for mobile phones using their built-in cameras is presented. By estimating the path connecting the center points of frames captured by the camera phone, objects of interest can be easily extracted and recognized. To estimate the movement of the mobile phone, corners and corresponding Speeded-Up Robust Features descriptors are used to calculate the spatial transformation parameters between the previous and current frames. These parameters are then used to recalculate the locations of the center points in the previous frame into the current frame. The experiment results obtained from real image sequences show that the proposed system is efficient, flexible, and able to provide accurate and stable results.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.1
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• pp.171-182
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• 2015

The general wavelet transform has profitable property in non-stationary signal analysis specially. The tunable Q-factor wavelet transform is a fully-discrete wavelet transform for which the Q-factor Q and the asymptotic redundancy r, of the transform are easily and independently specified. In particular, the specified parameters Q and r can be real-valued. Therefore, by tuning Q, the oscillatory behavior of the wavelet can be chosen to match the oscillatory behavior of the signal of interest, so as to enhance the sparsity of a sparse signal representation. The TQWT is well suited to fast algorithms for sparsity-based inverse problems because it is a Parseval frame, easily invertible, and can be efficiently implemented. The transform is based on a real valued scaling factor and is implemented using a perfect reconstruction over-sampled filter bank with real-valued sampling factors. The transform is parameterized by its Q-factor and its over-sampling rate, with modest over-sampling rates being sufficient for the analysis/synthesis functions to be well localized. This paper describes filter design of 2D discrete-time wavelet transform for which the Q-factor is easily specified. With the advantage of this transform, perfect reconstruction filter design and implementation for performance improvement are focused in this paper. Hence, the 2D transform can be tuned according to the oscillatory behavior of the image signal to which it is applied. Therefore, application for performance improvement in multimedia communication field was evaluated.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.7
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• pp.3594-3607
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• 2017

The traditional feature extraction methods such as principal component analysis (PCA) cannot obtain the local structure of the samples, and locally linear embedding (LLE) cannot obtain the global structure of the samples. However, a common drawback of existing PCA and LLE algorithm is that they cannot deal well with the sparse problem of the samples. Therefore, by integrating the globality of PCA and the locality of LLE with a sparse constraint, we developed an improved and unsupervised difference algorithm called Sparse Difference Embedding (SDE), for dimensionality reduction of high-dimensional data in small sample size problems. Significantly differing from the existing PCA and LLE algorithms, SDE seeks to find a set of perfect projections that can not only impact the locality of intraclass and maximize the globality of interclass, but can also simultaneously use the Lasso regression to obtain a sparse transformation matrix. This characteristic makes SDE more intuitive and more powerful than PCA and LLE. At last, the proposed algorithm was estimated through experiments using the Yale and AR face image databases and the USPS handwriting digital databases. The experimental results show that SDE outperforms PCA LLE and UDP attributed to its sparse discriminating characteristics, which also indicates that the SDE is an effective method for face recognition.

• Journal of Sensor Science and Technology
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• v.20 no.3
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• pp.178-186
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• 2011

Line tracking is a well defined method of mobile robot navigation. It is simple in concept, technically easy to implement, and already employed in many industrial sites. Among several different line tracking methods, magnetic sensing is widely used in practice. In comparison, vision-based tracking is less popular due mainly to its sensitivity to surrounding conditions such as brightness and floor characteristics although vision is the most powerful robotic sensing capability. In this paper, a vision-based robust path line detection technique is proposed for the navigation of a mobile robot assuming uncontrollable surrounding conditions. The technique proposed has four processing steps; color space transformation, pixel-level line sensing, block-level line sensing, and robot navigation control. This technique effectively uses hue and saturation color values in the line sensing so to be insensitive to the brightness variation. Line finding in block-level makes not only the technique immune from the error of line pixel detection but also the robot control easy. The proposed technique was tested with a real mobile robot and proved its effectiveness.

• International Commerce and Information Review
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• v.10 no.1
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• pp.97-115
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• 2008

This paper is to review how Korean trading companies perform and promote the digital transformation through the e-networking with global market, and how much they extend the volume of export, and make the company grow inward or outward in order to enhance the effects of economic growth in Korea. It is suggested that global agreement on e-Trade(or u-Trade) should be made in order to expand the global e-networking practices and to ensure transferring of transport documents(or business documents). Moreover, it also suggested that networking on the global trading partners such as government authorities, diplomatic offices abroad, overseas Koreans, students studying abroad, Korean merchants abroad, etc. should be made in single window for improving and upgrading the image of Korean trading companies. By making of global e-network platform between overseas business partners, trading companies are able to expect various synergy effects such as improving the satisfaction of their customers, promoting the global transactions, reducing the operation and transaction cost, helping fording overseas buyers, and extending export volume and sales profit, etc. Customers can also obtain the information about trading goods easily and rapidly, and cut down the transaction stage using information exchange with partners. All of the trading partners in the world can maintain their business partnership as long as they use the global e-network.

• Journal of Korea Multimedia Society
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• v.23 no.2
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• pp.127-134
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• 2020

In this paper, we propose a map alignment method for maps generated by point-line monocular SLAM. In the proposed method, the information of feature lines as well as feature points extracted from multiple maps are fused into a single map. To this end, the proposed method first searches for similar areas between maps via Bag-of-Words-based image matching. Thereafter, it calculates the similarity transformation between the maps in the corresponding areas to align the maps. Finally, we merge the overlapped information of multiple maps into a single map by removing duplicate information from similar areas. Experimental results show that maps created by different users are combined into a single map, and the accuracy of the fused map is similar with the one generated by a single user. We expect that the proposed method can be utilized for fast imagery map generation.

• Investigative Magnetic Resonance Imaging
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• v.11 no.1
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• pp.49-53
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• 2007

Fibrous dysplasia is a skeletal developmental anomaly of the bone-forming mesenchyme that manifests as a defect in osteoblastic differentiation and maturation. It is a nonhereditary disorder of unknown cause. In fibrous dysplasia, the medullary bone is replaced by fibrous tissue, which appears various imaging findings. It is usually an incidental finding, generally not requiring further investigation. However, fibrous dysplasia may be complicated by pathologic fracture, and rarely by malignant degeneration. We present the image findings of a 44-year-old man who had a chondroblastic osteosarcoma arising from polyostotic fibrous dysplasia in the femur. Evidence of cortical destruction on plain radiography and soft tissue mass in the lesion on MR images suggested a tumor of malignant transformation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.78-81
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• 2012

In this paper, we proposed the new vehicle license plates detection method which is available in a various fields, including vehicle access control, illegal parking and speeding vehicle crack down. First, we binarize an image by using difference of gaussian filter to find a sequence of numbers of plates. Second, we determine the plate region by labeling repeatedly using the morphological characteristics of the plates. Finally, we use a projective transformation for correcting the distortion that occurs because of the camera or the location of the vehicle.

• Korean Institute of Interior Design Journal
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• v.22 no.1
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• pp.154-163
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• 2013

This study is aimed to identify the expression and the sense of time in contemporary architectural space. And to classify the system and elements of Zeitlichkeit in the contemporary architectural design. The concept of time can be divided into two meaningful perceptions. Those are the concept of realistic time and the concept of subjective time. These tendencies of theories of architectural space has borrowed from innovations in the sciences, and the whole idea of space-time within art and architecture. Those notions developed through the researches of Bauhaus, Postmodernism, Landscape architecture, Digital Architecture and so forth. The result of this study is that the concepts of time are one of the most important strategies of architectural design and have the various languages which there was not in the past. At the point of the transformation in contemporary architecture, the The concepts of space-time are classified into those from the orders of form and space, from dynamic of the image in the dissolution of architectural form, from traces and steps of movement in dynamic form, and from the systems of commands in the digital softwares. As such, Zeitlichkeit in contemporary architecture means that the architecture moves from the construction of the sensual design elements into Art of life through events and contents which human can experience and recognize. These theories and researches reveal that contemporary architectural movements insert the meaningful stories into architectural space through programs and diagrams.