Anyang, South Korea

Anyang University, South Korea
Anyang, South Korea
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Lee S.-H.,Anyang University, South Korea
International Journal of Fuzzy Systems | Year: 2017

The aim of this study is to develop an embedded method for automatic diagnosis of ventricular fibrillation (VF) using a neuro-fuzzy system embedded in an automated external defibrillator (AED). To diagnose VF using AEDs, we use the neural network with weighted fuzzy membership functions (NEWFM), a wavelet transform (WT), a sequential increment method (SIM), and phase-space reconstruction (PSR) in order to classify normal sinus rhythm (NSR) and VF of electrocardiogram (ECG) episodes. This study has the following key points. The first contribution is the extraction of peaks from ECG episodes by the use of the WT and SIM by a time–frequency technique. The second contribution is that NSR and VF are distinguished by means of three-dimensional (3D) PSR based on a 3D graphic model. The third contribution is the identification of feature differences between NSR and VF by the use of graphical characteristics of weighted fuzzy membership functions (WFMs) supported by the NEWFM. The final contribution is the development of a neuro-fuzzy system for automatic diagnosis of VF using the WFMs embedded in the AED. The following four preprocessing steps are implemented to extract features from ECG episodes. In the first step, the WT is used for multi-scale representation and analysis and wavelet coefficients are then generated from the ECG episodes. In the second step, the SIM is used to extract peaks from the wavelet coefficients. In the third step, successive peaks are plotted in a 3D phase-space diagram by performing 3D PSR. In the final step, the distance between the origin (0, 0, 0) and the successive peaks plotted in a 3D phase-space diagram is calculated; then, 20 features are extracted from the calculated distances using statistical methods, including frequency distributions and their variability. The 20 extracted features are applied as inputs to the NEWFM, and the result is that the classification accuracy of the NEWFM is 100 %. © 2016, Taiwan Fuzzy Systems Association and Springer-Verlag Berlin Heidelberg.

Jung E.,Anyang University, South Korea
Lecture Notes in Electrical Engineering | Year: 2017

Domain Name System (DNS) log has been considered as a great source of valuable information for the decision making on government policy or business strategy because querying DNS is the first step of all Internet activities. Due to the size of DNS log, Hadoop is considered as a prominent solution, but the geographical dispersal of DNS log hinders to adopt it in an ordinary way. Hadoop assumes all data source should be located on a single Hadoop File System (HDFS), but DNS log is stored on DNS servers dispersed all over the world. To resolve this issue, a new method named “Localized Analysis & Merge (LAM)” is proposed in this paper. The proposed method enables Hadoop to analyze DNS log on the dispersed DNS servers and it reduced the whole processing time dramatically. Also, the LAM method showed that DNS log can be used to extract a lot of valuable information such as a malware detection, the access frequency over countries, etc. © Springer Nature Singapore Pte Ltd. 2017.

Lee H.Y.,Anyang University, South Korea
International journal of nanomedicine | Year: 2011

p-Phenylenediamine (PDA) or its related chemicals are used more extensively than oxidative hair dyes. However, permanent hair dyes such as PDA are known to have potent contact allergy reactions in humans, and severe allergic reactions are problematic. PDA-incorporated nanoparticles were prepared based on ion-complex formation between the cationic groups of PDA and the anionic groups of poly(γ-glutamic acid) (PGA). To reinforce PDA/PGA ion complexes, glycol chitosan (GC) was added. PDA-incorporated nanoparticles were characterized using field-emission scanning electron microscopy, Fourier- transform infrared (FT-IR) spectroscopy, dynamic light scattering, and powder X-ray diffractometry (XRD). Nanoparticles were formed by ion-complex formation between the amine groups of PDA and the carboxyl groups of PGA. PDA-incorporated nanoparticles are small in size (<100 nm), and morphological observations showed spherical shapes. FT-IR spectra results showed that the carboxylic acid peak of PGA decreased with increasing PDA content, indicating that the ion complexes were formed between the carboxyl groups of PGA and the amine groups of PDA. Furthermore, the intrinsic peak of the carboxyl groups of PGA was also decreased by the addition of GC. Intrinsic crystalline peaks of PDA were observed by XRD. This crystalline peak of PDA was completely nonexistent when nanoparticles were formed by ion complex between PDA, PGA, and GC, indicating that PDA was complexed with PGA and no free drug existed in the formulation. During the drug-release experiment, an initial burst release of PDA was observed, and then PDA was continuously released over 1 week. Cytotoxicity testing against HaCaT human skin keratinocyte cells showed PDA-incorporated nanoparticles had lower toxicity than PDA itself. Furthermore, PDA-incorporated nanoparticles showed reduced apoptosis and necrosis reaction at HaCaT cells. The authors suggest that these microparticles are ideal candidates for a vehicle for decreasing side effects of hair dye.

Wang C.M.,Anyang University, South Korea
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

We systematically study the anisotropic magnetoresistance (AMR) in a two-dimensional electron system with a combined Rashba and Dresselhaus spin-orbit interaction by exactly solving the kinetic equation. This AMR originates from the combination of spin-orbit coupling and in-plane magnetization, instead of the combined effect of spin-orbit coupling and polarized impurities emphasized in previous theoretical studies. A combined electromagnetic potential is taken into account to investigate the effect of impurity scattering. The electric component of the potential is long ranged, and both the positions and the directions of the magnetic moments of magnetic impurities are random. For long-range electric collision, AMR occurs and AMRs due to remote charged scatterers and background ones are comparable. For pure magnetic scattering, the magnitude of AMR is tiny when the magnetization is smaller than a singular magnetization. However, the anisotropy of spin-spin coupling can enhance the AMR and its magnitude reaches up to nearly 100% when only the majority band is occupied. For the combined electromagnetic potential, the magnitude of AMR is not very large and its sign is always positive when the electric part of scattering is remote. A sudden step of AMR emerges when the value of magnetization is near the Fermi energy, which is due to the uncontinuity of the density of state. © 2010 The American Physical Society.

Kim S.,Chungnam National University | Cho S.,Anyang University, South Korea
Journal of the American Society for Information Science and Technology | Year: 2013

Korea, along with Asia at large, is producing more and more valuable academic materials. Furthermore, the demand for academic materials produced in non-Western societies is increasing among English-speaking users. In order to search among such material, users rely on keywords such as author names. However, Asian nations such as Korea and China have markedly different methods of writing personal names from Western naming traditions. Among these differences are name components, structure, writing customs, and distribution of surnames. These differences influence the Anglicization of Asian academic researchers' names, often leading to them being written in various fashions, unlike Western personal names. These inconsistent formats can often lead to difficulties in searching and finding academic materials for Western users unfamiliar with Korean and Asian personal names. This article presents methods for precisely understanding and categorizing Korean personal names in order to make academic materials by Korean authors easier to find for Westerners. As such, this article discusses characteristics particular to Korean personal names and furthermore analyzes how the personal names of Korean academic researchers are currently being written in English. © 2012 ASIS&T.

Lee S.H.,Yonsei University | Park C.M.,Anyang University, South Korea | Seo Y.M.,Myongji University | Wang Z.G.,Tongji University | Kim C.K.,Yonsei University
Physical Review Letters | Year: 2010

We fabricated an acoustic composite structure consisting of a periodic array of interspaced membranes and side holes. Experimental data on the transmission, effective density, and phase velocity are presented. The system exhibits two critical frequencies, ωSH and ωc. Our metamaterial is double negative and transparent for frequencies lower than ωSH. For the frequencies ωSH<ω<ωc, the medium is opaque and only the density is negative. For the frequencies above ωc, the system is double positive and transparent. The present medium exhibits a very wide double negative spectral range that opens the possibility of the application of metamaterials for "white lights." © 2010 The American Physical Society.

Wang B.,Huazhong University of Science and Technology | Guan Z.-H.,Huazhong University of Science and Technology | Yuan F.-S.,Anyang University, South Korea
Automatica | Year: 2011

In this paper, the optimal tracking problem under control energy constraint is studied. The disturbance in the upstream channel and down channel is adequately considered. Some new results are derived and it is shown that the performance limitation is tightly dependent on the non-minimum phase zeros and the unstable poles. In addition, the performance limitation, which is greater than that of the disturbance only in the down channel, depends on other new non-minimum phase zeros. Finally, the example explains and validates the conclusion. © 2011 Elsevier Ltd. All rights reserved.

Park C.M.,Anyang University, South Korea | Park J.J.,Yonsei University | Lee S.H.,Yonsei University | Seo Y.M.,Myongji University | Kim C.K.,Yonsei University
Physical Review Letters | Year: 2011

We amplified acoustic evanescent waves using metamaterial slabs with a negative effective density. For the amplifying effect of the slab to overcome the dissipation, it is necessary that the imaginary part of the effective density is much smaller than the real part, a condition not satisfied so far. We report the construction of membrane-based two-dimensional negative-density metamaterials which exhibited remarkably small dissipation. Using a slab of this metamaterial we realized a 17-fold net amplitude gain at a remote distance from the evanescent wave source. Potential applications include acoustic superlensing. © 2011 American Physical Society.

Cui H.T.,Anyang University, South Korea
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

Overlap with the separable state is introduced in this article for the purpose of characterizing the overall correlation in many-body systems. This definition has clear geometric and physical meaning and moreover can be considered as the generalization of the concept of the Anderson orthogonality catastrophe. As an exemplification, it is used to mark the phase transition in the Dicke model for zero and finite temperatures, and the discussion shows that it can faithfully reflect the phase transition properties of this model whether for zero or finite temperature. Furthermore, the overlap for the ground state also indicates the appearance of multipartite entanglement in the Dicke model. © 2010 The American Physical Society.

Chang J.H.,Daegu University | Park N.H.,Anyang University, South Korea
Expert Systems with Applications | Year: 2012

Unlike the general sequential pattern mining that considers only the generation order of data elements, mining weighted sequential patterns aims to get more interesting sequential patterns by considering the weights of data elements in a target sequence database in addition to their generation order. In general, for a sequence or a sequential pattern, not only the generation order of data elements but also their generation times and time-intervals are important because they can be helpful in finding more interesting sequential patterns. Applying the mining method of time-interval weighted sequential (TiWS) patterns that has been proposed in our previous work, this paper proposes several sequence weighting approaches to get the time-interval weight of a sequence in mining TiWS patterns for a sequence database, and the effectiveness of each approach in mining TiWS patterns is analyzed through a set of experiments. The proposed sequence weighting approaches may be helpful in obtaining more interesting sequential patterns in mining sequential patterns for a sequence database. © 2011 Elsevier Ltd. All rights reserved.

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