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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Journal of Korean Institute of Communications and Information Sciences
Journal Basic Information
Journal DOI :
The Korean Institute of Communications and Information Sciences
Editor in Chief :
Kyung-Hi Chang / Song Chong / Jong-Taek Oh / Jae-Jin Lee / Myung-Sik Yoo
Volume & Issues
Volume 40, Issue 12 - Dec 2015
Volume 40, Issue 11 - Nov 2015
Volume 40, Issue 10 - Oct 2015
Volume 40, Issue 9 - Sep 2015
Volume 40, Issue 8 - Aug 2015
Volume 40, Issue 7 - Jul 2015
Volume 40, Issue 6 - Jun 2015
Volume 40, Issue 5 - May 2015
Volume 40, Issue 4 - Apr 2015
Volume 40, Issue 3 - Mar 2015
Volume 40, Issue 2 - Feb 2015
Volume 40, Issue 1 - Jan 2015
Selecting the target year
1 Bit/Pixel Modulation Codes for Multi-Level Holographic Data Storage System
Jeong, Seongkwon ; Lee, Jaejin ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1667~1671
DOI : 10.7840/kics.2015.40.9.1667
Multi-level holographic data storage is a candidate for the next generation data storage system, since it can store more than one bit per pixel. It is possible to increase the number of codewords if the number of levels is increased, and the code with an appropriate selection of codewords can also increase the minimum distance. In this paper, we propose three multi-level modulation codes of the code rate 1 bit/pixel and compare the performance according to the minimum distance. The result shows that the code with small number of levels is better than that of large number of levels because it is hard to detect threshold value.
Performance of 4-level Modulation Code for Holographic Data Storage
Park, Keunhwan ; Lee, Jaejin ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1672~1677
DOI : 10.7840/kics.2015.40.9.1672
The multi-level holographic storage system can store more than one bit per pixel. In this paper, we introduce a 6-pixel 4-level modulation code and compare with 4-level 6/9 modulation code and 2/3 modulation code. The proposed 6-pixel modulation code has the minimum Euclidean distance 3. The 6-pixel modulation code is approximately 1dB better than the other modulation codes.
Linear Precoding Based on the Imperfect CSI Without Knowing the CSI Reliability
Lee, Woong ; Yoon, Eunchul ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1678~1685
DOI : 10.7840/kics.2015.40.9.1678
We propose a linear precoding scheme combining the merits of beamforming and orthogonal space-time block coding based on the imperfect CSI without knowing the CSI reliability. We first investigate the impact of the CSI reliability on precoding performance by assuming various values of the CSI reliability. Then, we propose a method of predicting the CSI reliability based on the received SNR for the design of an efficient precoder. We show the efficiency of the proposed scheme by simulation.
Modified Genetic Algorithm for Fast Beam Formation in Wireless Network
Lee, Dong-kyu ; Ahn, Jong-min ; Park, Chul ; Kim, Han-na ; Chung, Jae-hak ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1686~1692
DOI : 10.7840/kics.2015.40.9.1686
This paper proposes a modified genetic algorithm that has the same beamforming performance and a fast convergence speed using general genetic algorithm in order to form a beam for the mobile node in a mesh network. The proposed beamforming genetic algorithm selects a part of chromosome a high fitness value in mating process to obtain fast convergence speed, and rest part of chromosome with longer fitness value in order to avoid local solution. Furthermore, the reference beam pattern with Gaussian shape reduces additional convergence speed. Simulation shows that the convergence speed of proposed algorithm improves 20% compared with that of conventional beamforming genetic algorithm.
Design of PFM Boost Converter with Dual Pulse Width Control
Choi, Ji-San ; Jo, Yong-Min ; Lee, Tae-Heon ; Yoon, Kwang-Sub ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1693~1698
DOI : 10.7840/kics.2015.40.9.1693
This paper proposed a PFM(pulse-frequency modulator) boost converter which has dual pulse-width. The PFM boost converter is composed of BGR(band gap voltage reference generating circuit), voltage reference generating circuit, soft-start circuit, error amplifier, high-speed comparator, inductor current sensing circuit and pulse-width generator. Converter has different inductor peak current so it has wider load current range and smaller output voltage ripple. Proposed PFM boost converter generates 18V output voltage with input voltage of 3.7V and it has load current range of 0.1~300mA. Simulation results show 0.43% output voltage ripple at ligh load mode and 0.79% output voltage ripple at heavy load mode. Converter has efficiency 85% at light lode mode and it has maximum 86.4% at 20mA load current.
Uplink Frequency Offset Compensation Scheme for High-Speed Moving Terminals
Choi, Sung-woo ; Kim, Ilgyu ; Ahn, Jae Min ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1699~1709
DOI : 10.7840/kics.2015.40.9.1699
Moving terminals like high-speed-train undergo high Doppler frequency shift, and this leads to carrier frequency offsets that have to be compensated to avoid degradation of communication performance. In multiple access mechanism like OFDMA, base-stations need complex hardware to compensate the uplink frequency offset. In this paper, we propose a method, which can reduce burden of the base-station and makes frequency offset estimation and compensation simple. This method contains transmitting new synchronization signal, estimating frequency offsets in base-station, transmitting feedback information to terminal, and compensating the offset in uplink transmission. Simulation results show the proposed method operates well in high Doppler frequency shift conditions of 500 km/h which is the requirements of 5G mobile communication.
Selected Mapping without Side Information at the Receiver
Jang, Chanki ; Yoon, Eunchul ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1710~1718
DOI : 10.7840/kics.2015.40.9.1710
Selected mapping (SLM) is an effective scheme to reduce the peak to average power ratio (PAPR) of an orthogonal frequency division multiplexing (OFDM) system. For data recovery, the receiver needs to know the side information (SI) on the scrambling sequence selected by the transmitter. In this paper, a new SLM scheme is proposed, which can reduce implementation complexity substantially by allowing the receiver to recover the data without SI. In the proposed SLM method, the concept of virtual channel corresponding to the convolution of the multipath channel and the inverse discrete fourier transform (IDFT) of the scrambling sequence is assumed. The receiver can recover the data without SI by using the virtual channel estimated with pilot signals. It is shown by simulation that the proposed SLM has PAPR reduction and BER performances similar to the previous SLM schemes while it can reduce implementation complexity substantially.
A Novel Frequency Allocation Algorithm for Limited Radio Resource Environments
Koo, Bonhong ; Chae, Chan-Byoung ; Park, Sung-Ho ; Park, Hwi-Sung ; Ham, Jae-Hyun ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1719~1721
DOI : 10.7840/kics.2015.40.9.1719
In this paper, we investigate a frequency assignment problem from graph theory for military communications. We propose an algorithm based on the graph coloring theory and confirm that we utilize 0.77 times lower number of frequencies. We also propose a hybrid algorithm that facilitates a trade-off between the range and the spectrum utilization gain.
An Efficient Partial Detection Scheme for MIMO-OFDM Systems
Kang, Sung-jin ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1722~1724
DOI : 10.7840/kics.2015.40.9.1722
This paper proposes a partial detection scheme using QRD-M, DFE, and iterative schemes for efficiency in terms of detection performance and complexity in a MIMO-OFDM system. The proposed scheme detects signals by using the different detection methods in according to spatial stream. In the proposed scheme, QRD-M with high detection performance and high complexity is used in spatial stream that requires low complexity, and DFE with low detection performance and low complexity is used in spatial stream that requires high complexity. Also, the iterative detection is performed in the detected spatial stream by using DFE. From the simulation, it is confirmed that although proposed scheme has increased complexity, detection performance is greatly improved by the proposed scheme.
QR Decomposition Based Sequential Belief Propagation Detection Scheme for MIMO Systems
Park, Sangjoon ; Choi, Sooyong ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1725~1727
DOI : 10.7840/kics.2015.40.9.1725
In this letter, a QR decomposition based sequential BP detection scheme is proposed for MIMO systems. The proposed scheme performs the sequential updates from the observation node having the smallest degree among all the observation nodes. Our simulation results verify that the proposed scheme achieves an improved error performance with a significantly accelerated detection convergence speed compared to the conventional schemes.
Parity Check Based Iterative Interference Cancellation Scheme for LDPC Coded MIMO Systems
Park, Sangjoon ; Choi, Sooyong ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1728~1730
DOI : 10.7840/kics.2015.40.9.1728
In this letter, a parity check based iterative IC scheme is proposed for LDPC coded MIMO systems. After the decoding procedures in each iteration of the proposed scheme, each decoded codeword is utilized for the IC procedures only when the ratio of the check nodes satisfying the parity check equations to the total number of check nodes is not smaller than the pre-defined threshold value. Simulation results verify that the proposed scheme can achieve an improved BLER at the high SNR region compared to the conventional iterative IC scheme.
Improvement of EEG-Based Drowsiness Detection System Using Discrete Wavelet Transform
Han, Hyungseob ; Song, Kyoung-Young ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1731~1733
DOI : 10.7840/kics.2015.40.9.1731
Since electroencephalogram(EEG) has non-linear and non-stationary properties, it is effective to analyze the characteristic of EEG with time-frequency method rather than spectrum method. In this letter, we propose the modified drowsiness detection system using discrete wavelet transform combined with errors-in-variables and multilayer perceptron methods. For the comparison of the proposed scheme with the previous one, the state 'others' is added to the previous states of drivers: 'alertness,' 'transition,' and 'drowsiness.' From the computer simulation using machine learning, we confirm that the proposed scheme outperforms the previous one for some conditions.
Binary Locally Repairable Codes from Complete Multipartite Graphs
Kim, Jung-Hyun ; Nam, Mi-Young ; Song, Hong-Yeop ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1734~1740
DOI : 10.7840/kics.2015.40.9.1734
This paper introduces a generalized notion, referred to as joint locality, of the usual locality in distributed storage systems and proposes a code construction of binary locally repairable codes with joint locality (
=3 or 4). Joint locality is a set of numbers of nodes for repairing various failure patterns of nodes. The proposed scheme simplifies the code design problem utilizing complete multipartite graphs. Moreover, our construction can generate binary locally repairable codes achieving (2,t)-availability for any positive integer t. It means that each node can be repaired by t disjoint repair sets of cardinality 2. This property is useful for distributed storage systems since it permits parallel access to hot data.
Locally Repairable Fractional Repetition Codes
Nam, Mi-Young ; Kim, Jung-Hyun ; Song, Hong-Yeop ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1741~1753
DOI : 10.7840/kics.2015.40.9.1741
In this paper, we introduce new locally repairable codes based on a Fractional repetition codes which is one of the MBR codes. We introduce two different constructions for different system parameters and compare these codes in terms of several performance metrics. There is some tradeoffs between the locality and other performance metrics. The newly introduced codes having the good locality should pay the price such as lower capacity or more storage nodes. And the proposed codes are more reliable than other locally repairable codes and have lower repair complexity since they can be repaired without any operations.
2-Dimensional Bitmap Tries for Fast Packet Classification
Seo, Ji-hee ; Lim, Hye-sook ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1754~1766
DOI : 10.7840/kics.2015.40.9.1754
Packet classification carried out in Internet routers is one of the challenging tasks, because it has to be performed at wire-speed using five header fields at the same time. In this paper, we propose a leaf-pushed AQT bitmap trie. The proposed architecture applies the leaf-pushing to an area-based quad-trie (AQT) to reduce unnecessary off-chip memory accesses. The proposed architecture also applies a bitmap trie, which is a kind of multi-bit tries, to improve search performance and scalability. For performance evaluation, simulations are conducted by using rule sets ACL, FW, and IPC, with the sizes of 1k, 5k, and 10k. Simulation results show that the number of off-chip memory accesses is less than one regardless of set types or set sizes. Additionally, since the proposed architecture applies a bitmap trie, the required number of on-chip memory accesses is the 50% of the leaf-pushed AQT trie. In addition, our proposed architecture shows good scalability in the required on-chip memory size, where the scalability is identified by the stable change in the required memory sizes, as the size of rule sets increases.
Topology Control Scheme Providing Throughput Requirement of a Service in Wireless Sensor Networks
Youn, Myungjune ; Kim, Seog-gyu ; Lee, Jaiyong ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1767~1775
DOI : 10.7840/kics.2015.40.9.1767
There are various kinds of applications for wireless sensor network, and each application has difference requirements such as throughput. Topology control is the key issue to minimize energy consumption by solving communication collision and radio interference. However, existing topology control algorithms cannot support application requirement because communication efficiency and network connectivity are the main issues of topology control. In this paper, we propose a topology control algorithm that support throughput requirement of an application.
Cache-Friendly Adaptive Video Streaming Framework Exploiting Regular Expression in Content Centric Networks
Son, Donghyun ; Choi, Daejin ; Choi, Nakjung ; Song, Junghwan ; Kwon, Ted Taekyoung ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1776~1785
DOI : 10.7840/kics.2015.40.9.1776
Content Centric Network (CCN) has been introduced as a new paradigm due to a shift of users's perspective of using Internet from host-centric to content-centric. On the other hand, a demand for video streaming has been increasing. Thus, Adaptive streaming has been introduced and researched for achieving higher user's satisfaction. If an architecture of Internet is replaced with CCN architecture, it is necessary to consider adaptive video streaming in CCN according to the demand of users. However, if the same rate decision algorithm used in Internet is deployed in CCN, there are a limitation of utilizing content store (CS) in CCN router and a problem of reflecting dynamic requirements. Therefore, this paper presents a framework adequate to CCN protocol and cache utilization, adapting content naming method of exploiting regular expression to the rate decision algorithm of the existing adaptive streaming. In addition, it also improves the quality of video streaming and verifies the performance through dynamic expression strategies and selection algorithm of the strategies.
Practical Implementation and Performance Evaluation of Random Linear Network Coding
Lee, Gyujin ; Shin, Yeonchul ; Koo, Jonghoe ; Choi, Sunghyun ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1786~1792
DOI : 10.7840/kics.2015.40.9.1786
Random linear network coding (RLNC) is widely employed to enhance the reliability of wireless multicast. In RLNC encoding/decoding, Galois Filed (GF) arithmetic is typically used since all the operations can be performed with symbols of finite bits. Considering the architecture of commercial computers, the complexity of arithmetic operations is constant regardless of the dimension of GF m, if m is smaller than 32 and pre-calculated tables are used for multiplication/division. Based on this, we show that the complexity of RLNC inversely proportional to m. Considering additional overheads, i.e., the increase of header length and memory usage, we determine the practical value of m. We implement RLNC in a commercial computer and evaluate the codec throughput with respect to the type of the tables for multiplication/division and the number of original packets to encode with each other.
Kernel RLS Algorithm Using Variable Forgetting Factor
Lim, Jun-Seok ; Pyeon, Yong-Guk ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1793~1801
DOI : 10.7840/kics.2015.40.9.1793
In a recent work, kernel recursive least-squares tracker (KRLS-T) algorithm has been proposed. It is capable of tracking in non-stationary environments using a forgetting mechanism built on a Bayesian framework. The forgetting mechanism in KRLS-T is implemented by a fixed forgetting factor. In practice, however, we frequently meet that the fixed forgetting factor cannot handle time-varying system effectively. In this paper we propose a new KRLS-T with a variable forgetting factor. Experimental results show that proposed algorithm can handle time-varying system more effectively than the KRLS-T.
Optimal Bidding Strategy for VM Spot Instances for Cloud Computing
Choi, Yeongho ; Lim, Yujin ; Park, Jaesung ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1802~1807
DOI : 10.7840/kics.2015.40.9.1802
The cloud computing service provides physical IT resources to VM instances to users using virtual technique and the users pay cost of VM instances to service provider. The auction model based on cloud computing provides available resources of service provider to users through auction mechanism. The users bid spot instances to process their a job until its deadline time. If the bidding price of users is higher than the spot price, the user will be provided the spot instances by service provider. In this paper, we propose a new bidding strategy to minimize the total cost for job completion. Typically, the users propose bidding price as high as possible to get the spot instances and the spot price get high. we lower the spot price using proposed strategy and minimize the total cost for job completion. To evaluate the performance of our strategy, we compare the spot price and the total cost for job completion with real workload data.
Implementation of Small-Scale Wind Turbine Monitoring and Control System Based on Wireless Sensor Network
Kim, Do-Young ; Kim, Young-Chon ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1808~1818
DOI : 10.7840/kics.2015.40.9.1808
Recently, the wind power has experienced great attentions and growths among many renewable energy sources. To increase the power generation performance and economic feasibility, the size of wind turbine (WT) is getting bigger and most of wind power plants are being constructed on offshore. Therefore, the maintenance cost is relatively high because boats or helicopters are needed operators to reach the WT. In order to combat this kind of problem, remote monitoring and control system for the WT is needed. In this paper, the small-scale WT monitoring and control system is implemented using wireless sensor network technologies. To do this, sensor devices are installed to measure and send the WT status and control device is installed to receive control message for specific operation. The WT is managed by control center through graphic user interface (GUI) based monitoring and control software. Also, smart device based web-program is implemented to make the remote monitoring of the WT possible even though operators are not in control room.
Preliminary Hazard Analysis for Development of ICT-Based Local Control Center
Sung, Yu-Suk ; Baek, Jong-Hyen ; Kim, Gonyop ; Kim, Youngju ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1819~1827
DOI : 10.7840/kics.2015.40.9.1819
ICT-based on-board oriented train control system has been proposed to improve operation efficiency in low-density railway line. It is also needed to develop a new ICT-based local control center which relates to existing centralized traffic control lines. In order to meet the qualitative target of these developing system, RAMS activities are required. In this paper, through preliminary hazard analysis, hazards and their contributing factors are addressed, then countermeasures are established to control the risk to an acceptable level.
Multiple Moving Object Detection Using Different Algorithms
Heo, Seong-Nam ; Son, Hyeon-Sik ; Moon, Byungin ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1828~1836
DOI : 10.7840/kics.2015.40.9.1828
Object tracking algorithms can reduce computational cost by avoiding computation over the whole image through the selection of region of interests based on object detection. So, accurate object detection is an important task for object tracking. The background subtraction algorithm has been widely used in moving object detection using a stationary camera. However, it has the problem of object detection error due to incorrect background modeling, whereas the method of background modeling has been improved by many researches. This paper proposes a new moving object detection algorithm to overcome the drawback of the conventional background subtraction algorithm by combining the background subtraction algorithm with the motion history image algorithm that is usually used in gesture detection. Although the proposed algorithm demands more processing time because of time taken for combining two algorithms, it meet the real-time processing requirement. Moreover, experimental results show that it has higher accuracy compared with the previous two algorithms.
Vehicular Pitch Estimation Algorithm with ACF/IMMKF Based on GPS/IMU/OBD Data Fusion
Kim, Ju-won ; Lee, Myung-su ; Lee, Sang-sun ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1837~1845
DOI : 10.7840/kics.2015.40.9.1837
The longitudinal velocity is necessary for accurate vehicular positioning in urban environment. The pitch angle, which is a road slope, should be calculated to acquire the longitudinal velocity. However, it is impossible to consider very accurate pitch, when using a sensor and an algorithm. That's why process noise and positioning stimation error of IMU should be adjusted to the driving environment and fuse GPS, OBD data with ACF which consist of AKF, CF in this paper. Then, final pitch angle which is appropriate for driving environment is estimated by IMMKF in order to optimize the system model according to road slope models.
A Precise Relative Positioning Method Based on Time-Differenced Carrier Phase Measurements from Low-Cost GNSS Receiver
Park, Kwi-Woo ; Lee, DongSun ; Park, Chansik ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1846~1855
DOI : 10.7840/kics.2015.40.9.1846
In this paper, a precise relative positioning with TD(time differenced) carrier phase measurements from a low-cost GNSS(Global Navigation Satellite System) receiver is proposed and analysed. The proposed method is using carrier phase measurement from a single GNSS receiver that reference receiver is not required and stand alone positioning is possible. TD operation removes the troublesome integer ambiguity resolution problem, and if the time interval is short, other error, such as, ionospheric, tropospheric delay and ephemeris error are effectively eliminated. The error analysis of the proposed method shows that a precise and positioning with carrier phase is possible. The implemented system is evaluated using a real car experiments. The results show that the horizontal positioning error was less than 3m during 10 minutes experiments, which is 4 times more precise than the results of normal code based absolute positioning.
Indoor Localization Algorithm Using Smartphone Sensors and Probability of Normal Distribution in Wi-Fi Environment
Lee, Jeong-Yong ; Lee, Dong Myung ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 9, 2015, Pages 1856~1864
DOI : 10.7840/kics.2015.40.9.1856
In this paper, the localization algorithm for improving the accuracy of the positioning using the Wi-Fi fingerprint using the normal distribution probability and the built-in typed accelerometer sensor, the gyroscope sensor of smartphone in the indoor environment is proposed. The experiments for analyzing the performance of the proposed algorithm were carried out at the region of the horizontal and vertical 20m * 10m in the engineering school building of our university, and the performance of the proposed algorithm is compared with the fingerprint and the DR (dead reckoning) while user is moving according to the assigned region. As a result, the maximum error distance in the proposed algorithm was decreased to 2cm and 36cm compared with two algorithms, respectively. In addition to this, the maximum error distance was also less than compared with two algorithms as 16.64cm and 36.25cm, respectively. It can be seen that the fingerprint map searching time of the proposed algorithm was also reduced to 0.15 seconds compared with two algorithms.