Search results for: Chul Gyu Song
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 188

Search results for: Chul Gyu Song

158 Identification of Arousal and Relaxation by using SVM-Based Fusion of PPG Features

Authors: Chi Jung Kim, Mincheol Whang, Eui Chul Lee

Abstract:

In this paper, we propose a new method to distinguish between arousal and relaxation states by using multiple features acquired from a photoplethysmogram (PPG) and support vector machine (SVM). To induce arousal and relaxation states in subjects, 2 kinds of sound stimuli are used, and their corresponding biosignals are obtained using the PPG sensor. Two features–pulse to pulse interval (PPI) and pulse amplitude (PA)–are extracted from acquired PPG data, and a nonlinear classification between arousal and relaxation is performed using SVM. This methodology has several advantages when compared with previous similar studies. Firstly, we extracted 2 separate features from PPG, i.e., PPI and PA. Secondly, in order to improve the classification accuracy, SVM-based nonlinear classification was performed. Thirdly, to solve classification problems caused by generalized features of whole subjects, we defined each threshold according to individual features. Experimental results showed that the average classification accuracy was 74.67%. Also, the proposed method showed the better identification performance than the single feature based methods. From this result, we confirmed that arousal and relaxation can be classified using SVM and PPG features.

Keywords: Support Vector Machine, PPG, Emotion Recognition, Arousal, Relaxation

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157 Multi-Objective Optimization for Performance-based Seismic Retrofit using Connection Upgrade

Authors: Dong-Chul Lee, Byung-Kwan Oh, Se-Woon Choi, Hyo-Sun Park

Abstract:

The unanticipated brittle fracture of connection of the steel moment resisting frame (SMRF) occurred in 1994 the Northridge earthquake. Since then, the researches for the vulnerability of connection of the existing SMRF and for rehabilitation of those buildings were conducted. This paper suggests performance-based optimal seismic retrofit technique using connection upgrade. For optimal design, a multi-objective genetic algorithm(NSGA-II) is used. One of the two objective functions is to minimize initial cost and another objective function is to minimize lifetime seismic damages cost. The optimal algorithm proposed in this paper is performed satisfying specified performance objective based on FEMA 356. The nonlinear static analysis is performed for structural seismic performance evaluation. A numerical example of SAC benchmark SMRF is provided using the performance-based optimal seismic retrofit technique proposed in this paper

Keywords: connection upgrade, performace-based seismicdesign, seismic retrofit, multi-objective optimization

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156 Coordinated Multi-Point Scheme Based On Channel State Information in MIMO-OFDM System

Authors: Su-Hyun Jung, Chang-Bin Ha, Hyoung-Kyu Song

Abstract:

Recently, increasing the quality of experience (QoE) is an important issue. Since performance degradation at cell edge extremely reduces the QoE, several techniques are defined at LTE/LTE-A standard to remove inter-cell interference (ICI). However, the conventional techniques have disadvantage because there is a trade-off between resource allocation and reliable communication. The proposed scheme reduces the ICI more efficiently by using channel state information (CSI) smartly. It is shown that the proposed scheme can reduce the ICI with fewer resources.

Keywords: Adaptive beam forming, CoMP, LTE-A, ICI reduction.

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155 Dynamic Behaviors of a Floating Bridge with Mooring Lines under Wind and Wave Excitations

Authors: Chungkuk Jin, Moohyun Kim, Woo Chul Chung

Abstract:

This paper presents global performance and dynamic behaviors of a discrete-pontoon-type floating bridge with mooring lines in time domain under wind and wave excitations. The structure is designed for long-distance and deep-water crossing and consists of the girder, columns, pontoons, and mooring lines. Their functionality and behaviors are investigated by using elastic-floater/mooring fully-coupled dynamic simulation computer program. Dynamic wind, first- and second-order wave forces, and current loads are considered as environmental loads. Girder’s dynamic responses and mooring tensions are analyzed under different analysis methods and environmental conditions. Girder’s lateral responses are highly influenced by the second-order wave and wind loads while the first-order wave load mainly influences its vertical responses.

Keywords: Floating bridge, elastic dynamic response, coupled dynamics, mooring line, pontoon, wave/wind excitation, resonance, second-order effect.

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154 Analysis of Target Location Estimation in High Performance Radar System

Authors: Jin-Hyeok Kim, Won-Chul Choi, Seung-Ri Jin, Dong-Jo Park

Abstract:

In this paper, an analysis of a target location estimation system using the best linear unbiased estimator (BLUE) for high performance radar systems is presented. In synthetic environments, we are here concerned with three key elements of radar system modeling, which makes radar systems operates accurately in strategic situation in virtual ground. Radar Cross Section (RCS) modeling is used to determine the actual amount of electromagnetic waves that are reflected from a tactical object. Pattern Propagation Factor (PPF) is an attenuation coefficient of the radar equation that contains the reflection from the surface of the earth, the diffraction, the refraction and scattering by the atmospheric environment. Clutter is the unwanted echoes of electronic systems. For the data fusion of output results from radar detection in synthetic environment, BLUE is used and compared with the mean values of each simulation results. Simulation results demonstrate the performance of the radar system.

Keywords: Best linear unbiased estimator (BLUE) , data fusion, radar system modeling, target location estimation

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153 Production of WGHs and AFPHs using Protease Combinations at High and Ambient Pressure

Authors: Namsoo Kim, So-Hee Son, Jin-Soo Maeng, Yong-Jin Cho, Chul-Jin Kim, Chong-Tai Kim

Abstract:

Wheat gluten hydrolyzates (WGHs) and anchovy fine powder hydrolyzates (AFPHs) were produced at 300 MPa using combinations of Flavourzyme 500MG (F), Alcalase 2.4L (A), Marugoto E (M) and Protamex (P), and then were compared to those produced at ambient pressure concerning the contents of soluble solid (SS), soluble nitrogen and electrophoretic profiles. The contents of SS in the WGHs and AFPHs increased up to 87.2% according to the increase in enzyme number both at high and ambient pressure. Based on SS content, the optimum enzyme combinations for one-, two-, three- and four-enzyme hydrolysis were determined as F, FA, FAM and FAMP, respectively. Similar trends were found for the contents of total soluble nitrogen (TSN) and TCA-soluble nitrogen (TCASN). The contents of SS, TSN and TCASN in the hydrolyzates together with electrophoretic mobility maps indicates that the high-pressure treatment of this study accelerated protein hydrolysis compared to ambient-pressure treatment.

Keywords: Production, Wheat gluten hydrolyzates, Anchovy fine powder hydrolyzates, Protease combinations.

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152 Numerical Simulation of Fluid-Structure Interaction on Wedge Slamming Impact Using Particle Method

Authors: Sung-Chul Hwang, Di Ren, Sang-Moon Yoon, Jong-Chun Park, Abbas Khayyer, Hitoshi Gotoh

Abstract:

This paper presents a fully Lagrangian coupled Fluid-Structure Interaction (FSI) solver for simulations of fluid-structure interactions, which is based on the Moving Particle Semi-implicit (MPS) method to solve the governing equations corresponding to incompressible flows as well as elastic structures. The developed solver is verified by reproducing the high velocity impact loads of deformable thin wedges with three different materials such as mild steel, aluminium and tin during water entry. The present simulation results for aluminium are compared with analytical solution derived from the hydrodynamic Wagner model and linear Wan’s theory. And also, the impact pressure and strain on the water entry wedge with three different materials, such as mild steel, aluminium and tin, are simulated and the effects of hydro-elasticity are discussed.

Keywords: Fluid-structure interaction (FSI), Moving Particle Semi-implicit (MPS) method, Elastic structure, Incompressible fluid Wedge slamming impact.

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151 Privacy Threats in RFID Group Proof Schemes

Authors: HyoungMin Ham, JooSeok Song

Abstract:

RFID tag is a small and inexpensive microchip which is capable of transmitting unique identifier through wireless network in a short distance. If a group of RFID tags can be scanned simultaneously by one reader, RFID Group proof could be generated. Group proof can be used in various applications, such as good management which is usually achieved using barcode system. A lot of RFID group proof schemes have been proposed by many researchers. In this paper, we introduce some existing group proof schemes and then analyze their vulnerabilities to the privacy. Moreover, we propose a new attack model, which threats the privacy of user by tracking tags in a group.

Keywords: grouping proof, privacy, RFID, yoking proof

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150 3D Model Retrieval based on Normal Vector Interpolation Method

Authors: Ami Kim, Oubong Gwun, Juwhan Song

Abstract:

In this paper, we proposed the distribution of mesh normal vector direction as a feature descriptor of a 3D model. A normal vector shows the entire shape of a model well. The distribution of normal vectors was sampled in proportion to each polygon's area so that the information on the surface with less surface area may be less reflected on composing a feature descriptor in order to enhance retrieval performance. At the analysis result of ANMRR, the enhancement of approx. 12.4%~34.7% compared to the existing method has also been indicated.

Keywords: Interpolated Normal Vector, Feature Descriptor, 3DModel Retrieval.

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149 Low-MAC FEC Controller for JPEG2000 Image Transmission Over IEEE 802.15.4

Authors: Kyu-Yeul Wang, Sang-Seol Lee, Jea-Yeon Song, Jea-Young Choi, Seong-Seob Shin, Dong-Sun Kim, Duck-Jin Chung

Abstract:

In this paper, we propose the low-MAC FEC controller for practical implementation of JPEG2000 image transmission using IEEE 802.15.4. The proposed low-MAC FEC controller has very small HW size and spends little computation to estimate channel state. Because of this advantage, it is acceptable to apply IEEE 802.15.4 which has to operate more than 1 year with battery. For the image transmission, we integrate the low-MAC FEC controller and RCPC coder in sensor node of LR-WPAN. The modified sensor node has increase of 3% hardware size than conventional zigbee sensor node.

Keywords: FEC, IEEE 802.15.4, JPEG2000, low-MAC.

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148 How CATV Survive in the Era of Convergence?

Authors: J. Park, J. Song, B. Lee

Abstract:

The purpose of this paper is to analyze the case of the U.S. Pivot and to suggest an appropriate model including entry strategies and success factors for QPS of Cable TV. The telecommunication companies have been operating QPS including IPTV service, which enables them to cross over broadcasting areas. Due to this circumstance, the Cable TV operators are now concerned and are planning to add QPS with the mobile service. Based on the Porter's five forces model, an analytical framework has been proposed to MVNO in Cable TV industry in the United States. As a result of this study, MVNO in Cable TV industry has to have a clear killer application with their sufficient contents. Subsequently, the direction of the future Cable TV industry is proposed.

Keywords: CATV, MVNO, Pivot, QPS

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147 An Improved Transmission Scheme in Cooperative Communication System

Authors: Seung-Jun Yu, Young-Min Ko, Hyoung-Kyu Song

Abstract:

Recently developed cooperative diversity scheme enables a terminal to get transmit diversity through the support of other terminals. However, most of the introduced cooperative schemes have a common fault of decreased transmission rate because the destination should receive the decodable compositions of symbols from the source and the relay. In order to achieve high data rate, we propose a cooperative scheme that employs hierarchical modulation. This scheme is free from the rate loss and allows seamless cooperative communication.

Keywords: Cooperative communication, hierarchical modulation, high data rate, transmission scheme.

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146 Parallelization and Optimization of SIFT Feature Extraction on Cluster System

Authors: Mingling Zheng, Zhenlong Song, Ke Xu, Hengzhu Liu

Abstract:

Scale Invariant Feature Transform (SIFT) has been widely applied, but extracting SIFT feature is complicated and time-consuming. In this paper, to meet the demand of the real-time applications, SIFT is parallelized and optimized on cluster system, which is named pSIFT. Redundancy storage and communication are used for boundary data to improve the performance, and before representation of feature descriptor, data reallocation is adopted to keep load balance in pSIFT. Experimental results show that pSIFT achieves good speedup and scalability.

Keywords: cluster, image matching, parallelization and optimization, SIFT.

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145 Hybrid MIMO-OFDM Detection Scheme for High Performance

Authors: Young-Min Ko, Dong-Hyun Ha, Chang-Bin Ha, Hyoung-Kyu Song

Abstract:

In recent years, a multi-antenna system is actively used to improve the performance of the communication. A MIMO-OFDM system can provide multiplexing gain or diversity gain. These gains are obtained in proportion to the increase of the number of antennas. In order to provide the optimal gain of the MIMO-OFDM system, various transmission and reception schemes are presented. This paper aims to propose a hybrid scheme that base station provides both diversity gain and multiplexing gain at the same time.

Keywords: DFE, diversity gain, hybrid, MIMO, multiplexing gain.

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144 Mooring Analysis of Duct-Type Tidal Current Power System in Shallow Water

Authors: Chul H. Jo, Do Y. Kim, Bong K. Cho, Myeong J. Kim

Abstract:

The exhaustion of oil and the environmental pollution from the use of fossil fuel are increasing. Tidal current power (TCP) has been proposed as an alternative energy source because of its predictability and reliability. By applying a duct and single point mooring (SPM) system, a TCP device can amplify the generating power and keep its position properly. Because the generating power is proportional to cube of the current stream velocity, amplifying the current speed by applying a duct to a TCP system is an effective way to improve the efficiency of the power device. An SPM system can be applied at any water depth and is highly cost effective. Simple installation and maintenance procedures are also merits of an SPM system. In this study, we designed an SPM system for a duct-type TCP device for use in shallow water. Motions of the duct are investigated to obtain the response amplitude operator (RAO) as the magnitude of the transfer function. Parameters affecting the stability of the SPM system such as the fairlead departure angle, current velocity, and the number of clamp weights are analyzed and/or optimized. Wadam and OrcaFlex commercial software is used to design the mooring line.

Keywords: Mooring design, parametric analysis, response amplitude operator, single point mooring.

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143 A Simulation for Estimation of the Blood Pressure using Arterial Pressure-volume Model

Authors: Gye-rok Jeon, Jae-hee Jung, In-cheol Kim, Ah-young Jeon, Sang-hwa Yoon, Jung-man Son, Jae-hyung Kim, Soo-young Ye, Jung-hoon Ro, Dong-hyun Kim, Chul-han Kim

Abstract:

A analysis on the conventional the blood pressure estimation method using an oscillometric sphygmomanometer was performed through a computer simulation using an arterial pressure-volume (APV) model. Traditionally, the maximum amplitude algorithm (MAP) was applied on the oscillation waveforms of the APV model to obtain the mean arterial pressure and the characteristic ratio. The estimation of mean arterial pressure and characteristic ratio was significantly affected with the shape of the blood pressure waveforms and the cutoff frequency of high-pass filter (HPL) circuitry. Experimental errors are due to these effects when estimating blood pressure. To find out an algorithm independent from the influence of waveform shapes and parameters of HPL, the volume oscillation of the APV model and the phase shift of the oscillation with fast fourier transform (FFT) were testified while increasing the cuff pressure from 1 mmHg to 200 mmHg (1 mmHg per second). The phase shift between the ranges of volume oscillation was then only observed between the systolic and the diastolic blood pressures. The same results were also obtained from the simulations performed on two different the arterial blood pressure waveforms and one hyperthermia waveform.

Keywords: Arterial blood pressure, oscillometric method

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142 CFD Simulation for Air-Borne Infection Analysis in AII-Room

Authors: Young Kwon Yang, In Sung Kang, Jung Ha Hwang, Jin Chul Park

Abstract:

The present study is a foundational study for performance improvements on isolation wards to prevent proliferation of secondary infection of infectious diseases such as SARS, H1N1, and MERS inside hospitals. Accordingly, the present study conducted an analysis of the effect of sealing mechanisms and filling of openings on ensuring air tightness performance in isolation wards as well as simulation on air currents in improved isolation wards. The study method is as follows. First, previous studies on aerial infection type and mechanism were reviewed, and the review results were utilized as basic data of analysis on simulation of air current. Second, national and international legislations and regulations in relation to isolation wards as well as case studies on developed nations were investigated in order to identify the problems in isolation wards in Korea and improvement plans. Third, construction and facility plans were compared and analyzed between general and isolation wards focusing on large general hospitals in Korea, thereby conducting comparison and analysis on the performance and effects of air-tightness of general and isolation wards through CFD simulations. The study results showed that isolation wards had better air-tightness performance than that of general wards.

Keywords: AII Room, air-borne infection, CFD, computational fluid dynamics.

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141 Advanced Micromanufacturing for Ultra Precision Part by Soft Lithography and Nano Powder Injection Molding

Authors: Andy Tirta, Yus Prasetyo, Eung-Ryul. Baek, Chul-Jin. Choi , Hye-Moon. Lee

Abstract:

Recently, the advanced technologies that offer high precision product, relative easy, economical process and also rapid production are needed to realize the high demand of ultra precision micro part. In our research, micromanufacturing based on soft lithography and nanopowder injection molding was investigated. The silicone metal pattern with ultra thick and high aspect ratio succeeds to fabricate Polydimethylsiloxane (PDMS) micro mold. The process followed by nanopowder injection molding (PIM) by a simple vacuum hot press. The 17-4ph nanopowder with diameter of 100 nm, succeed to be injected and it forms green sample microbearing with thickness, microchannel and aspect ratio is 700μm, 60μm and 12, respectively. Sintering process was done in 1200 C for 2 hours and heating rate 0.83oC/min. Since low powder load (45% PL) was applied to achieve green sample fabrication, ~15% shrinkage happen in the 86% relative density. Several improvements should be done to produce high accuracy and full density sintered part.

Keywords: Micromanufacturing, Nano PIM, PDMS micro mould.

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140 Improved Wi-Fi Backscatter System for Multi-to-Multi Communication

Authors: Chang-Bin Ha, Yong-Jun Kim, Dong-Hyun Ha, Hyoung-Kyu Song

Abstract:

The conventional Wi-Fi backscatter system can only process one-to-one communication between the Wi-Fi reader and the Wi-Fi tag. For improvement of throughput of the conventional system, this paper proposes the multi-to-multi communication system. In the proposed system, the interference by the multi-to-multi communication is effectively cancelled by the orthogonal multiple access based on the identification code of the tag. Although the overhead is generated by the procedure for the multi-to-multi communication, because the procedure is processed by the Wi-Fi protocol, the overhead is insignificant for the entire communication procedure. From the numerical results, it is confirmed that the proposed system has nearly proportional increased throughput in according to the number of the tag that simultaneously participates in communication.

Keywords: Backscatter, Multi-to-multi communication, Orthogonality, Wi-Fi.

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139 Intuitionistic Fuzzy Points in Semigroups

Authors: Sujit Kumar Sardar Manasi Mandal Samit Kumar Majumder

Abstract:

The notion of intuitionistic fuzzy sets was introduced by Atanassov as a generalization of the notion of fuzzy sets. Y.B. Jun and S.Z. Song introduced the notion of intuitionistic fuzzy points. In this paper we find some relations between the intuitionistic fuzzy ideals of a semigroup S and the set of all intuitionistic fuzzy points of S.

Keywords: Semigroup, Regular(intra-regular) semigroup, Intuitionistic fuzzy point, Intuitionistic fuzzy subsemigroup, Intuitionistic fuzzy ideal, Intuitionistic fuzzy interior ideal, Intuitionistic fuzzy semiprime ideal, Intuitionistic fuzzy prime ideal.

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138 SCR-Based Advanced ESD Protection Device for Low Voltage Application

Authors: Bo Bae Song, Byung Seok Lee, Hyun Young Kim, Chung Kwang Lee, Yong Seo Koo

Abstract:

This paper proposed a silicon controller rectifier (SCR) based ESD protection device to protect low voltage ESD for integrated circuit. The proposed ESD protection device has low trigger voltage and high holding voltage compared with conventional SCR-based ESD protection devices. The proposed ESD protection circuit is verified and compared by TCAD simulation. This paper verified effective low voltage ESD characteristics with low trigger voltage of 5.79V and high holding voltage of 3.5V through optimization depending on design variables (D1, D2, D3 and D4).

Keywords: ESD, SCR, Holding voltage, Latch-up.

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137 Cooperative Scheme Using Adjacent Base Stations in Wireless Communication

Authors: Young-Min Ko, Seung-Jun Yu, Chang-Bin Ha, Hyoung-Kyu Song

Abstract:

In a wireless communication system, the failure of base station can result in a communication disruption in the cell. This paper proposes a way to deal with the failure of base station in a wireless communication system based on OFDM. Cooperative communication of the adjacent base stations can be a solution of the problem. High performance is obtained by the configuration of transmission signals which is applied CDD scheme in the cooperative communication. The Cooperative scheme can be a e ective solution in case of the particular situation.

Keywords: Base station, CDD, OFDM, Diversity gain, MIMO.

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136 Efficient Variable Modulation Scheme Based on Codebook in the MIMO-OFDM System

Authors: Yong-Jun Kim, Jae-Hyun Ro, Chang-Bin Ha, Hyoung-Kyu Song

Abstract:

Because current wireless communication requires high reliability in a limited bandwidth environment, this paper proposes the variable modulation scheme based on the codebook. The variable modulation scheme adjusts transmission power using the codebook in accordance with channel state. Also, if the codebook is composed of many bits, the reliability is more improved by the proposed scheme. The simulation results show that the performance of proposed scheme has better reliability than the the performance of conventional scheme.

Keywords: MIMO-OFDM, variable modulation, codebook, channel state.

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135 Electrical Characteristics of SCR - based ESD Device for I/O and Power Rail Clamp in 0.35um Process

Authors: Yong Seo Koo, Dong Su Kim, Byung Seok Lee, Won Suk Park, Bo Bea Song

Abstract:

This paper presents a SCR-based ESD protection devices for I/O clamp and power rail clamp, respectably. These devices have a low trigger voltage and high holding voltage characteristics than conventional SCR device. These devices are fabricated by using 0.35um BCD (Bipolar-CMOS-DMOS) processes. These devices were validated using a TLP system. From the experimental results, the device for I/O ESD clamp has a trigger voltage of 5.8V. Also, the device for power rail ESD clamp has a holding voltage of 7.7V.

Keywords: ESD (Electro-Static Discharge), ESD protection device, SCR (Silicon Controlled Rectifier), Latch-up

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134 A Novel Spectrum Sensing Scheme Based on Periodicity of DVB-T Pilot Signals

Authors: Hyung-Weon Cho, Youngyoon Lee, Seung Goo Kang, Dahae Chong, Myungsoo Lee, Chonghan Song, Seokho Yoon

Abstract:

This paper proposes a novel spectrum sensing technique for the digital video broadcasting-terrestrial (DVB-T) systems, which utilizes the periodicity of pilot signals in the orthogonal frequency division multiplexing (OFDM) symbols. The proposed scheme can overcome the effect of the timing synchronization error by recorrelating the correlation values in the same sample distances. The numerical results demonstrate that the detection probability performance of the proposed scheme outperforms that of the conventional scheme when there exists a timing synchronization error.

Keywords: DVB-T, spectrum sensing, OFDM, timing synchronizationerror.

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133 A High-Crosstalk Silicon Photonic Arrayed Waveguide Grating

Authors: Qing Fang, Lianxi Jia, Junfeng Song, Chao Li, Xianshu Luo, Mingbin Yu, Guoqiang Lo

Abstract:

In this paper, we demonstrated a 1 × 4 silicon photonic cascaded arrayed waveguide grating, which is fabricated on a SOI wafer with a 220 nm top Si layer and a 2µm buried oxide layer. The measured on-chip transmission loss of this cascaded arrayed waveguide grating is ~ 5.6 dB, including the fiber-to-waveguide coupling loss. The adjacent crosstalk is 33.2 dB. Compared to the normal single silicon photonic arrayed waveguide grating with a crosstalk of ~ 12.5 dB, the crosstalk of this device has been dramatically increased.

Keywords: Silicon photonic, arrayed waveguide grating, high-crosstalk, cascaded structure.

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132 A Collaborative Framework for Visual Modeling on Web 2.0

Authors: Song Meng, Dianfu Ma, Yongwang Zhao, Jianxin Li

Abstract:

Cooperative visual modeling is more and more necessary in our complicated world. A collaborative environment which supports interactive operation and communication is required to increase work efficiency. We present a collaborative visual modeling framework which collaborative platform could be built on. On this platform, cooperation and communication is available for designers from different regions. This framework, which is different from other collaborative frameworks, contains a uniform message format, a message handling mechanism and other functions such as message pretreatment and Role-Communication-Token Access Control (RCTAC). We also show our implementation of this framework called Orchestra Designer, which support BPLE workflow modeling cooperatively online.

Keywords: colllaborative framework; visual modeling; message handling mechanism

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131 Cooperative CDD Scheme Based On Adaptive Modulation in Wireless Communication System

Authors: Seung-Jun Yu, Hwan-Jun Choi, Hyoung-Kyu Song

Abstract:

Among spatial diversity scheme, orthogonal space-time block code (OSTBC) and cyclic delay diversity (CDD) have been widely studied for the cooperative wireless relaying system. However, conventional OSTBC and CDD cannot cope with change in the number of relays owing to low throughput or error performance. In this paper, we propose a cooperative cyclic delay diversity (CDD) scheme that use hierarchical modulation at the source and adaptive modulation based on cyclic redundancy check (CRC) code at the relays.

Keywords: Adaptive modulation, Cooperative communication, CDD, OSTBC.

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130 Hydrothermal Fabrication of Iodine Doped Titanium Oxide Films on Ti Substrate

Authors: M. P. Neupane, T. S. N. Sankara Narayanan, J. E. Park, Y. K. Kim, I. S. Park, K. Y. Song, T. S. Bae, M. H. Lee

Abstract:

Titanium oxide films with different morphologies have for the first time been fabricated through hydrothermal reactions between a titanium substrate and iodine powder in water or ethanol. SEM revealed that iodine supported titanium (Ti-I2) surface shows different morphologies with variable treatment conditions. The mean surface roughness (Ra) was increased in the different groups. Use of surfactant has a role to increase the roughness of the film. The surface roughness was in the range of 0.15 μm-0.42 μm. Furthermore, the electrochemical examinations showed that the Ti-I2 surface fabricated in alcoholic medium has high corrosion resistance than in aqueous medium.

Keywords: Corrosion, Hydrothermal, Surface roughness, Titanium oxide.

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129 A Study on Cancer-Cell Invasion Based On the Diffuse Interface Model

Authors: Zhang Linan, Jihwan Song, Dongchoul Kim

Abstract:

In this study, a three-dimensional haptotaxis model to simulate the migration of a population of cancer cells has been proposed. The invasion of cancer cells is related with the hapto-attractant and the effect of the interface energies between the cells and the ECM. The diffuse interface model, which incorporates the haptotaxis mechanism and interface energies, is employed. The semi-implicit Fourier spectral scheme is adopted for efficient evaluation of the simulation. The simulation results thoroughly reveal the dynamics of cancer-cell migration.

Keywords: Haptotaxis, Cancer Cells, Cell Migration, Interface Energy, Diffuse Interface Model

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