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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal DOI :
Electronics and Telecommunications Research Institute
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Volume & Issues
Volume 33, Issue 6 - Dec 2011
Volume 33, Issue 5 - Oct 2011
Volume 33, Issue 4 - Aug 2011
Volume 33, Issue 3 - Jun 2011
Volume 33, Issue 2 - Apr 2011
Volume 33, Issue 1 - Feb 2011
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Packet Size Optimization for Improving the Energy Efficiency in Body Sensor Networks
Domingo, Mari Carmen ;
ETRI Journal, volume 33, issue 3, 2011, Pages 299~309
DOI : 10.4218/etrij.11.0110.0270
Energy consumption is a key issue in body sensor networks (BSNs) since energy-constrained sensors monitor the vital signs of human beings in healthcare applications. In this paper, packet size optimization for BSNs has been analyzed to improve the efficiency of energy consumption. Existing studies on packet size optimization in wireless sensor networks cannot be applied to BSNs because the different operational characteristics of nodes and the channel effects of in-body and on-body propagation cannot be captured. In this paper, automatic repeat request (ARQ), forward error correction (FEC) block codes, and FEC convolutional codes have been analyzed regarding their energy efficiency. The hop-length extension technique has been applied to improve this metric with FEC block codes. The theoretical analysis and the numerical evaluations reveal that exploiting FEC schemes improves the energy efficiency, increases the optimal payload packet size, and extends the hop length for all scenarios for in-body and on-body propagation.
A New Soft-Fusion Approach for Multiple-Receiver Wireless Communication Systems
Aziz, Ashraf M. ; Elbakly, Ahmed M. ; Azeem, Mohamed H.A. ; Hamid, Gamal A. ;
ETRI Journal, volume 33, issue 3, 2011, Pages 310~319
DOI : 10.4218/etrij.11.0110.0282
In this paper, a new soft-fusion approach for multiple-receiver wireless communication systems is proposed. In the proposed approach, each individual receiver provides the central receiver with a confidence level rather than a binary decision. The confidence levels associated with the local receiver are modeled by means of soft-membership functions. The proposed approach can be applied to wireless digital communication systems, such as amplitude shift keying, frequency shift keying, phase shift keying, multi-carrier code division multiple access, and multiple inputs multiple outputs sensor networks. The performance of the proposed approach is evaluated and compared to the performance of the optimal diversity, majority voting, optimal partial decision, and selection diversity in case of binary noncoherent frequency shift keying on a Rayleigh faded additive white Gaussian noise channel. It is shown that the proposed approach achieves considerable performance improvement over optimal partial decision, majority voting, and selection diversity. It is also shown that the proposed approach achieves a performance comparable to the optimal diversity scheme.
Closed-Form Expressions for Selection Combining System Statistics over Correlated Generalized-K Fading Channels in the Presence of Interference
Nikolic, Bojana Z. ; Stefanovic, Mihajlo C. ; Panic, Stefan R. ; Anastasov, Jelena A. ; Milosevic, Borivoje ;
ETRI Journal, volume 33, issue 3, 2011, Pages 320~325
DOI : 10.4218/etrij.11.0110.0311
This paper considers the effects of simultaneous correlated multipath fading and shadowing on the performances of a signal-to-interference ratio (SIR)-based dual-branch selection combining (SC) diversity receiver. This analysis includes the presence of cochannel interference. A generalized fading/shadowing channel model in an interference-limited correlated fading environment is modeled by generalized-K distribution. Closed-form expressions are obtained for probability density function and cumulative distribution function of the SC output SIR, as well as for the outage probability. Based on this, the influence of various fading and shadowing parameter values and the correlation level on the outage probability is examined.
Sampling Jitter Effect on a Reconfigurable Digital IF Transceiver to WiMAX and HSDPA
Yu, Bong-Guk ; Lee, Jae-Kwon ; Kim, Jin-Up ; Lim, Kyu-Tae ;
ETRI Journal, volume 33, issue 3, 2011, Pages 326~334
DOI : 10.4218/etrij.11.0110.0339
This paper outlines the time jitter effect of a sampling clock on a software-defined radio technology-based digital intermediate frequency (IF) transceiver for a mobile communication base station. The implemented digital IF transceiver is reconfigurable to high-speed data packet access (HSDPA) and three bandwidth profiles: 1.75 MHz, 3.5 MHz, and 7 MHz, each incorporating the IEEE 802.16d worldwide interoperability for microwave access (WiMAX) standard. This paper examines the relationship between the signal-to-noise ratio (SNR) characteristics of a digital IF transceiver with an under-sampling scheme and the sampling jitter effect on a multichannel orthogonal frequency-division multiplexing (OFDM) signal. The simulation and experimental results show that the SNR of the OFDM system with narrower band profiles is more susceptible to sampling clock jitter than systems with relatively wider band profiles. Further, for systems with a comparable bandwidth, HSDPA outperforms WiMAX, for example, a 5 dB error vector magnitude improvement at 15 picoseconds time jitter for a bandwidth of WiMAX 3.5 MHz profile.
Wideband Low-Reflection Transmission Lines for Bare Chip on Multilayer PCB
Ramzan, Rashad ; Fritzin, Jonas ; Dabrowski, Jerzy ; Svensson, Christer ;
ETRI Journal, volume 33, issue 3, 2011, Pages 335~343
DOI : 10.4218/etrij.11.0110.0386
The pad pitch of modern radio frequency integrated circuits is in the order of few tens of micrometers. Connecting a large number of high-speed I/Os to the outside world with good signal fidelity at low cost is an extremely challenging task. To cope with this requirement, we need reflection-free transmission lines from an on-chip pad to on-board SMA connectors. Such a transmission line is very hard to design due to the difference in on-chip and on-board feature size and the requirement for extremely large bandwidth. In this paper, we propose the use of narrow tracks close to chip and wide tracks away from the chip. This narrow-to-wide transition in width results in impedance discontinuity. A step change in substrate thickness is utilized to cancel the effect of the width discontinuity, thus achieving a reflection-free microstrip. To verify the concept, several microstrips were designed on multilayer FR4 PCB without any additional manufacturing steps. The TDR measurements reveal that the impedance variation is less than 3
for a 50
microstrip and S11 better than -9 dB for the frequency range 1 GHz to 6 GHz when the width changes from 165
, and substrate thickness changes from 100
Coded and Scalar Prefix Trees: Prefix Matching Using the Novel Idea of Double Relation Chains
Behdadfar, Mohammad ; Saidi, Hossein ; Hashemi, Massoud Reza ; Lin, Ying-Dar ;
ETRI Journal, volume 33, issue 3, 2011, Pages 344~354
DOI : 10.4218/etrij.11.0110.0381
In this paper, a model is introduced named double relation chains (DRC) based on ordered sets. It is proved that using DRC and special relationships among the members of an alphabet, vectors of this alphabet can be stored and searched in a tree. This idea is general; however, one special application of DRC is the longest prefix matching (LPM) problem in an IP network. Applying the idea of DRC to the LPM problem makes the prefixes comparable like numbers using a pair of w-bit vectors to store at least one and at most w prefixes, where w is the IP address length. This leads to good compression performance. Based on this, two recently introduced structures called coded prefix trees and scalar prefix trees are shown to be specific applications of DRC. They are implementable on balanced trees which cause the node access complexity for prefix search and update procedures to be O(log n) where n is the number of prefixes. As another advantage, the number of node accesses for these procedures does not depend on w. Additionally, they need fewer number of node accesses compared to recent range-based solutions. These structures are applicable on both IPv4 and IPv6, and can be implemented in software or hardware.
New Approach to Inter-domain Multicast Protocols
Leal, Raquel Perez ; Cachinero, Juan Angel ; Martin, Encarna Pastor ;
ETRI Journal, volume 33, issue 3, 2011, Pages 355~365
DOI : 10.4218/etrij.11.0110.0405
IPTV broadcast channels and video content distribution are increasingly saturating network paths. New solutions based on inter-domain multicast protocols could contribute to the enhancement of multimedia content distribution over the Internet. The aim of this paper is to propose new capabilities for an existing inter-domain multicast protocol, the Protocol Independent Multicast-Sparse Mode. We describe the modified protocol and analyze its behavior using newly developed tools based on an open-source software simulator. The resulting protocol does not require topology information, which is advantageous for easier deployment. In addition, the adopted solution avoids inherent problems with inter-domain multicast routing, such as multiple paths and path asymmetries.
Low-Power, All Digital Phase-Locked Loop with a Wide-Range, High Resolution TDC
Pu, Young-Gun ; Park, An-Soo ; Park, Joon-Sung ; Lee, Kang-Yoon ;
ETRI Journal, volume 33, issue 3, 2011, Pages 366~373
DOI : 10.4218/etrij.11.0110.0295
In this paper, we propose a low-power all-digital phase-locked loop (ADPLL) with a wide input range and a high resolution time-to-digital converter (TDC). The resolution of the proposed TDC is improved by using a phase-interpolator and the time amplifier. The phase noise of the proposed ADPLL is improved by using a fine resolution digitally controlled oscillator (DCO) with an active inductor. In order to control the frequency of the DCO, the transconductance of the active inductor is tuned digitally. The die area of the ADPLL is 0.8
CMOS technology. The frequency resolution of the TDC is 1 ps. The DCO tuning range is 58% at 2.4 GHz and the effective DCO frequency resolution is 0.14 kHz. The phase noise of the ADPLL output at 2.4 GHz is -120.5 dBc/Hz with a 1 MHz offset. The total power consumption of the ADPLL is 12 mW from a 1.2 V supply voltage.
An Internal Pattern Run-Length Methodology for Slice Encoding
Lee, Lung-Jen ; Tseng, Wang-Dauh ; Lin, Rung-Bin ;
ETRI Journal, volume 33, issue 3, 2011, Pages 374~381
DOI : 10.4218/etrij.11.0110.0319
A simple and effective compression method is proposed for multiple-scan testing. For a given test set, each test pattern is compressed from the view of slices. An encoding table exploiting seven types of frequently-occurring pattern is used. Compression is then achieved by mapping slice data into codewords. The decompression logic is small and easy to implement. It is also applicable to schemes adopting a single-scan chain. Experimental results show this method can achieve good compression effect.
Streaming RFID: Robust Stream Transmission over Passive RFID
Hwang, Seok-Joong ; Han, Young-Sun ; Kim, Seon-Wook ; Kim, Jong-Ok ;
ETRI Journal, volume 33, issue 3, 2011, Pages 382~392
DOI : 10.4218/etrij.11.0110.0458
This paper proposes the streaming radio frequency identification (RFID) protocol to support robust data streaming in a passive communication, which is extended from the ISO18000-6 Type C RFID standard. By observing and modeling the unique bit error behavior through detailed analysis in this paper, we found that performance is significantly limited by inaccurate and unstable link frequencies as well as low SNR which are inevitable for passive devices. Based on the analysis, we propose a simple and efficient protocol to adaptively insert extra error control sequences in a packet for tolerating tough link condition while maximizing the throughput and preserving the minimal implementation cost. To evaluate effectiveness of our proposal in real-time streaming applications, we experimented on real-time H.264 video streaming and prototyped the system on FPGA. To our best knowledge, our paper is the first work to take analytical approach for maximizing the throughput and demonstrate the possibility of the realtime multimedia streaming transmission in the passive RFID system.
Design of Two-Stage Class AB CMOS Buffers: A Systematic Approach
Martin, Antonio Lopez ; Miguel, Jose Maria Algueta ; Acosta, Lucia ; Ramirez-Angulo, Jaime ; Carvajal, Ramon Gonzalez ;
ETRI Journal, volume 33, issue 3, 2011, Pages 393~400
DOI : 10.4218/etrij.11.0110.0465
A systematic approach for the design of two-stage class AB CMOS unity-gain buffers is proposed. It is based on the inclusion of a class AB operation to class A Miller amplifier topologies in unity-gain negative feedback by a simple technique that does not modify quiescent currents, supply requirements, noise performance, or static power. Three design examples are fabricated in a 0.5
CMOS process. Measurement results show slew rate improvement factors of approximately 100 for the class AB buffers versus their class A counterparts for the same quiescent power consumption (< 200
A Fast Normalized Cross Correlation-Based Block Matching Algorithm Using Multilevel Cauchy-Schwartz Inequality
Song, Byung-Cheol ;
ETRI Journal, volume 33, issue 3, 2011, Pages 401~406
DOI : 10.4218/etrij.11.0110.0315
This paper presents a fast block-matching algorithm based on the normalized cross-correlation, where the elimination order is determined based on the gradient magnitudes of subblocks in the current macroblock. Multilevel Cauchy-Schwartz inequality is derived to skip unnecessary block-matching calculations in the proposed algorithm. Also, additional complexity reduction is achieved re-using the normalized cross correlation values for the spatially neighboring macroblock because the search areas of adjacent macroblocks are overlapped. Simulation results show that the proposed algorithm can improve the speed-up ratio up to about 3 times in comparison with the existing algorithm.
Adaptive Online Voltage Scaling Scheme Based on the Nash Bargaining Solution
Kim, Sung-Wook ;
ETRI Journal, volume 33, issue 3, 2011, Pages 407~414
DOI : 10.4218/etrij.11.0110.0417
In an effort to reduce energy consumption, research into adaptive power management in real-time systems has become widespread. In this paper, a novel dynamic voltage scaling scheme is proposed for multiprocessor systems. Based on the concept of the Nash bargaining solution, a processor's clock speed and supply voltage are dynamically adjusted to satisfy these conflicting performance metrics. In addition, the proposed algorithm is implemented to react adaptively to the current system conditions by using an adaptive online approach. Simulation results clearly indicate that the superior performance of the proposed scheme can strike the appropriate performance balance between contradictory requirements.
Vision-Based Finger Action Recognition by Angle Detection and Contour Analysis
Lee, Dae-Ho ; Lee, Seung-Gwan ;
ETRI Journal, volume 33, issue 3, 2011, Pages 415~422
DOI : 10.4218/etrij.11.0110.0313
In this paper, we present a novel vision-based method of recognizing finger actions for use in electronic appliance interfaces. Human skin is first detected by color and consecutive motion information. Then, fingertips are detected by a novel scale-invariant angle detection based on a variable k-cosine. Fingertip tracking is implemented by detected region-based tracking. By analyzing the contour of the tracked fingertip, fingertip parameters, such as position, thickness, and direction, are calculated. Finger actions, such as moving, clicking, and pointing, are recognized by analyzing these fingertip parameters. Experimental results show that the proposed angle detection can correctly detect fingertips, and that the recognized actions can be used for the interface with electronic appliances.
An Adaptive Utterance Verification Framework Using Minimum Verification Error Training
Shin, Sung-Hwan ; Jung, Ho-Young ; Juang, Biing-Hwang ;
ETRI Journal, volume 33, issue 3, 2011, Pages 423~433
DOI : 10.4218/etrij.11.0110.0489
This paper introduces an adaptive and integrated utterance verification (UV) framework using minimum verification error (MVE) training as a new set of solutions suitable for real applications. UV is traditionally considered an add-on procedure to automatic speech recognition (ASR) and thus treated separately from the ASR system model design. This traditional two-stage approach often fails to cope with a wide range of variations, such as a new speaker or a new environment which is not matched with the original speaker population or the original acoustic environment that the ASR system is trained on. In this paper, we propose an integrated solution to enhance the overall UV system performance in such real applications. The integration is accomplished by adapting and merging the target model for UV with the acoustic model for ASR based on the common MVE principle at each iteration in the recognition stage. The proposed iterative procedure for UV model adaptation also involves revision of the data segmentation and the decoded hypotheses. Under this new framework, remarkable enhancement in not only recognition performance, but also verification performance has been obtained.
Differential Fault Analysis for Round-Reduced AES by Fault Injection
Park, Jea-Hoon ; Moon, Sang-Jae ; Choi, Doo-Ho ; Kang, You-Sung ; Ha, Jae-Cheol ;
ETRI Journal, volume 33, issue 3, 2011, Pages 434~442
DOI : 10.4218/etrij.11.0110.0478
This paper presents a practical differential fault analysis method for the faulty Advanced Encryption Standard (AES) with a reduced round by means of a semi-invasive fault injection. To verify our proposal, we implement the AES software on the ATmega128 microcontroller as recommended in the standard document FIPS 197. We reduce the number of rounds using a laser beam injection in the experiment. To deduce the initial round key, we perform an exhaustive search for possible key bytes associated with faulty ciphertexts. Based on the simulation result, our proposal extracts the AES 128-bit secret key in less than 10 hours with 10 pairs of plaintext and faulty ciphertext.
Evaluating the Efficiency of Mobile Content Companies Using Data Envelopment Analysis and Principal Component Analysis
Cho, Eun-Jin ; Park, Myeong-Cheol ;
ETRI Journal, volume 33, issue 3, 2011, Pages 443~453
DOI : 10.4218/etrij.11.0110.0430
This paper evaluates the efficiency of mobile content firms through a hybrid approach combining data envelopment analysis (DEA) to analyze the relative efficiency and performance of firms and principal component analysis (PCA) to analyze data structures. We performed a DEA using the total amount of assets, operating costs, employees, and years in business as inputs, and revenue as output. We calculated fifteen combinations of DEA efficiency in the mobile content firms. We performed a PCA on the results of the fifteen DEA models, dividing the mobile content firms into those having either 'asset-oriented' or 'manpower and experience-oriented' efficiency. Discriminant analysis was used to validate the relationship between the efficiency models and mobile content types. This paper contributes toward the construction of a framework that combines the DEA and PCA approaches in mobile content firms for use in comprehensive measurements. Such a framework has the potential to present major factors of efficiency for sustainable management in mobile content firms and to aid in planning mobile content industry policies.
Classification of Degradation Types Based on Distribution of Blocky Blocks for IP-Based Video Services
Min, Kyung-Yeon ; Lee, Seon-Oh ; Sim, Dong-Gyu ; Lee, Hyun-Woo ; Ryu, Won ; Lee, Kyoung-Hee ;
ETRI Journal, volume 33, issue 3, 2011, Pages 454~457
DOI : 10.4218/etrij.11.0210.0277
In this letter, we propose a new quality measurement method to identify the causes of video quality degradation for IP-based video services. This degradation mainly results from network performance issues and video compression. The proposed algorithm identifies the causes based on statistical feature values from blocky block distribution in degraded IP-based videos. We found that the sensitivity and specificity of the proposed algorithm are 93.63% and 91.99%, respectively, in comparison with real error types and subjective test data.
A Time-Optimal Anti-collision Algorithm for FSA-Based RFID Systems
Lee, Dong-Hwan ; Choi, Ji-Hoon ; Lee, Won-Jun ; Pack, Sang-Heon ; Du, Ding-Zhu ; Hong, Sang-Jin ;
ETRI Journal, volume 33, issue 3, 2011, Pages 458~461
DOI : 10.4218/etrij.11.0210.0243
With the introduction of the new generation RFID technology, EPCglobal Class-1 Generation-2, there is considerable interest in improving the performance of the framed slotted Aloha (FSA)-based tag collision arbitration protocol. We suggest a novel time-optimal anti-collision algorithm for the FSA protocol. Our performance evaluation demonstrates that our algorithm outperforms other tag collision arbitration schemes.
Millimeter-Wave High-Linear CMOS Low-Noise Amplifier Using Multiple-Gate Transistors
Kim, Ji-Hoon ; Choi, Woo-Yeol ; Quraishi, Abdus Samad ; Kwon, Young-Woo ;
ETRI Journal, volume 33, issue 3, 2011, Pages 462~465
DOI : 10.4218/etrij.11.0210.0235
A millimeter-wave (mm-wave) high-linear low-noise amplifier (LNA) is presented using a 0.18
standard CMOS process. To improve the linearity of mm-wave LNAs, we adopted the multiple-gate transistor (MGTR) topology used in the low frequency range. By using an MGTR having a different gate-source bias at the last stage of LNAs, third-order input intercept point (IIP3) and 1-dB gain compression point (
) increase by 4.85 dBm and 4 dBm, respectively, without noise figure (NF) degradation. At 33 GHz, the proposed LNAs represent 9.5 dB gain, 7.13 dB NF, and 6.25 dBm IIP3.
Fine-Grained FSMD Power Gating Considering Power Overhead
Shin, Chi-Hoon ; Oh, Myeong-Hoon ; Sim, Jae-Woo ; Jeong, Jae-Chan ; Kim, Seong-Woon ;
ETRI Journal, volume 33, issue 3, 2011, Pages 466~469
DOI : 10.4218/etrij.11.0210.0328
As a fine-grained power gating method for achieving greater power savings, our approach takes advantage of the finite state machine with a datapath (FSMD) characteristic which shows sequential idleness among subcircuits. In an FSMD-based power gating, while only an active subcircuit is expected to be turned on, more subcircuits should be activated due to the power overhead. To reduce the number of missed opportunities for power savings, we deactivated some of the turned-on subcircuits by slowing the FSMD down and predicting its behavior. Our microprocessor experiments showed that the power savings are close to the upper bound.
Blackbox and Scenario-Based Testing of Online Games Using Game Description Language
Cho, Chang-Sik ; Lee, Dong-Chun ; Sohn, Kang-Min ; Park, Chang-Joon ; Kang, Ji-Hoon ;
ETRI Journal, volume 33, issue 3, 2011, Pages 470~473
DOI : 10.4218/etrij.11.0210.0172
In this letter, we propose blackbox and scenario-based testing of multiplayer online games as well as simple load testing. Game testing is done from outside the source code, and the access to the source code is not required to testers because the game logic is described with a game description language and virtual game map. Instead of using a subset of the main game client for the test client, only game packet protocols and the sequence of packets are analyzed for new game testing. In addition, complex and various scenarios can be tested through combining defined actions. Scenario-based testing helps testers mimic real testing environments instead of doing simple load testing and improves the productivity of game testing.