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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
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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
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Optimum Conditions of Adaptive Equalizers Based on Zero-Error Probability
Kim, Namyong ; Lee, Gyoo-Yeong ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1865~1870
DOI : 10.7840/kics.2015.40.10.1865
In signal processing, the zero-error probability (ZEP) criterion and related algorithm (MZEP) outperforms MSE-based algorithms and yields superior and stable convergence in impulsive noise environment. In this paper, the analysis of the relationship with MSE criterion proves that ZEP criterion has equivalent optimum solution of MSE criterion. Also this work reveals that the magnitude controlled input of MZEP algorithm plays the role in keeping the optimum solution undisturbed from impulsive noise.
Transmission Performance Improvement Using Brightness Deviation for Visual-MIMO System
Kim, Hee-jin ; Kwon, Tae-ho ; Park, Young-il ; Kim, Ki-doo ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1871~1878
DOI : 10.7840/kics.2015.40.10.1871
Recently, research on the Visual-MIMO by applying the concept of MIMO to communication between the LED array and camera is in progress. Although we already introduced the method for bit decision by using reference LED array pattern, it has the disadvantage of measuring the ISI each time when there is a change in the distance. To overcome this, in this paper, we propose a bit decision and error correction method used by using the luminance deviation without using the reference array pattern. First, we execute the bit decision using experimentally determined threshold. Next, we execute the error checking on the ON-LED and make a correction only if it is found to be error. Correction is determined by using the value of brightness deviation corresponding to the range of 68.2% (1) around the maximum frequency of the histogram for each ON-LED. We verify the performance of the proposed method according to the variation of ISI with distance by using both numerical and experimental analysis.
Adjacent Channel Coexistence of LTE in Unlicensed Spectrum
Lim, Su Hwan ; Jung, Man Young ; Lee, Sang-Wook ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1879~1888
DOI : 10.7840/kics.2015.40.10.1879
This paper evaluates the adjacent channel coexistence issues between LAA(License Assisted Access) system and other system (e.g. Wi-Fi) system in 5 GHz unlicensed spectrum. LAA is a technology to achieve enhanced data rate by aggregating licensed and unlicensed spectrum using CA(Carrier Aggregation). The coexistence study is essential before deploying LTE in unlicensed spectrum to verify the impact of LTE on the existing system such as Wi-Fi including system in throughput and regulatory aspects. This paper evaluates and analyzes the RF requirements of LTE system using interference analysis of coexistence study when operating at adjacent frequency channel of the Wi-Fi system in order to minimize the impact of LTE system into Wi-Fi system.
Multiple Slot Reservation for Rapid Data Traffic Transmission in the Satellite Random Access Channel
Lee, Yun-sung ; Lee, Jin-seok ; Lim, Jae-sung ; Park, Hyung-won ; Noh, Hong-jun ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1889~1899
DOI : 10.7840/kics.2015.40.10.1889
In this paper, we propose a multiple slot reservation scheme to transmit data rapidly in the satellite random access channel. In the R-CRDSA (Reservation scheme with Contention Resolution Diversity Slotted ALOHA), each satellite terminal can use only one slot in a frame. Therefore, many slots are wasting in the low traffic load and the satellite terminals which have large date needs many frame to transmit their data although there are unused slots. In the multiple slot reservation scheme, each satellite terminal transmits a packet with their data size and reserves many slots in the light of data size and slot reservation status. Therefore, each satellite terminal transmits their data faster than R-CRDSA. This is because they can reserve many slots in a frame. Furthermore, we simulate proposed scheme and validate the performance of proposed scheme.
Backscatter Communication for Wireless-Powered Communication Networks
Choi, Shin Hyuk ; Kim, Dong In ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1900~1911
DOI : 10.7840/kics.2015.40.10.1900
In this paper, we introduce backscatter communication for power-limited sensors to enable long-range transmission in wireless sensor networks, and envision a way to avoid doubly near-far problem in wireless-powered communication network (WPCN) with this technology. In backscatter based WPCN, users harvest energy from both the signal broadcasted by the hybrid access point and the carrier signal transmitted by the carrier emitter in the downlink, and then transmit their own information in a passive way via the reflection of the carrier signal using frequency-shift keying modulation in the uplink. We characterize the energy-free condition and the signal-to-noise ratio (SNR) outage zone in backscatter based WPCN. Further, we propose backscatter based harvest-then-transmit protocol to maximize the sum-throughput of the backscatter based WPCN by optimally allocating time for energy harvesting and information transmission. Numerical results demonstrate that the backscatter based WPCN increases significantly the transmission range and diminishes greatly the SNR outage zone.
RF Energy Transfer Testbed Based on Off-the-shelf Components for IoT Application
Aziz, Arif Abdul ; Tribudi, Dimas ; Ginting, Lorenz ; Rosyady, Phisca Aditya ; Setiawan, Dedi ; Choi, Kae Won ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1912~1921
DOI : 10.7840/kics.2015.40.10.1912
In this paper, we introduce a testbed for testing the RF energy transfer technology in the Internet of Things (IoT) environment, and provide experimental results obtained by using the testbed. The IoT environment considered in this paper consists of a power beacon, which is able to wirelessly transfers energy via microwave, and multiple sensor nodes, which makes use of the energy received from the power beacon. We have implemented the testbed to experiment the RF energy transfer in such IoT environment. We have used off-the-shelf hardware components to build the testbed and have made the tesbed controlled by software so that various energy and data transmission protocol experiments can easily be conducted. We also provide experimental results and discuss the future research direction.
Development of Far Field RF Power Harvesting Testbed
Kim, Min Jae ; Lim, Wonseob ; Bae, Jongseok ; Park, Ju Hyun ; Park, Young Jun ; Lee, Jong Min ; Trinh-Van, Son ; Kim, Dong In ; Lee, Kang Yoon ; Hwang, Keum Cheol ; Yang, Youngoo ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1922~1930
DOI : 10.7840/kics.2015.40.10.1922
This paper presents the system design, implement, and measurement results of the testbed for the wireless RF energy harvesting system. The developed testbed can be used for RF power transfer and data communication using the 2.4 GHz and 900 MHz frequency bands. It allows to evaluate the system performances for the RF power and data transmission. The testbed can also be used to develop algorithms for efficient energy harvesting.
Inter-Cell Cooperative Transmission Scheme for Improving Reliability at the Heterogeneous Network
Kang, Sung-jin ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1931~1933
DOI : 10.7840/kics.2015.40.10.1931
This paper proposes inter-cell cooperative transmission scheme in order to improve the reliability of the wireless communication system at the heterogeneous network environments. The heterogeneous network can increase data rate by using existing network technologies. However, degradation of communication performance in the cell edge has been a serious problem. Therefore, this letter proposes an adaptive transmission scheme according to the diverse situations in order to solve this problem.
An Optimal Relay Selection and Adaptive Throughput Enhancement Scheme Utilizing Superposition Modulation
Kang, Sung-jin ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1934~1936
DOI : 10.7840/kics.2015.40.10.1934
This paper proposes an optimal relay selection and adaptive throughput enhancement scheme utilizing superposition modulation in cooperative communication. The optimal relay is selected and the channel state is estimated by utilizing superposition modulation. The source determines the number of superimposed signal in accordance with the estated channel state. As a result, throughput is increased in accordance with the channel state.
Multiple Linear Chirp Based Transmission Scheme for IEEE 802.15.4a Chirp Spread Spectrum
Kim, Kwang-yul ; Lee, Seung-woo ; Kim, Yong-sin ; Lee, Jae-seang ; Kim, Jin-young ; Shin, Yoan ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1937~1939
DOI : 10.7840/kics.2015.40.10.1937
In order to improve the performance of a chirp based transmission scheme, the cross-coherence property should be carefully considered. In this paper, we propose two pairs of combinations using multiple linear chirp (MLC) which can reduce the cross-coherence for improving IEEE 802.15.4a chirp spread spectrum systems. The simulation results show that the proposed MLC scheme can improve the performance by considering the cross-coherence.
Analysis and Compensation of I/Q Amplitude Imbalance In Coherent PON Systems
Kim, Nayeong ; Lee, Seungwoo ; Park, Youngil ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1940~1946
DOI : 10.7840/kics.2015.40.10.1940
An optical coherent system is considered for the next-generation optical access networks in enhancing the data rate and transmission distance. In this system, however, I/Q amplitude imbalance may occur at several parts of the system, leading to serious performance degradation. Asymmetric structure of a coherent receiver at the location of subscriber is one of the sources of I/Q imbalance. Therefore, this imbalance parameters must be removed or compensated to secure the transmission performance. In this paper, the source of I/Q amplitude imbalance is analyzed, and then the way to compensate for the imbalance at the receiver side is suggested. Performance after the compensation is estimated using simulation.
CCN-Helper Performance Analysis for Data Transmission Delay over Federated Testbed Environment
Choi, Won-jun ; Ramneek, Ramneek ; Seok, Woo-jin ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1947~1957
DOI : 10.7840/kics.2015.40.10.1947
CCN networking is one of the future internet. With the rapid development of network platforms emerged a wide range of services through a virtual network environment. The performance of CCN in the high bandwidth delay is important to provide various services between nations. We can check the high bandwidth delay product in federation. Federation between the nations has the advantage of being effective to do a various services for the users, and the remote heterogeneous physical hardware engine supports various environments. Data transmission delay can be occur in long distance network even though the network is federated network. In this paper, we propose CCN-Helper protocol for data transmission delay in ling distance networks. We connect from KREONET in Korea to iLab.t in Belgique in order to test CCNx over heterogeneous federated environment.
Chameleon Hash-Based Mutual Authentication Protocol for Secure Communications in OneM2M Environments
Kim, Sung-soo ; Jun, Moon-seog ; Choi, Do-hyeon ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1958~1968
DOI : 10.7840/kics.2015.40.10.1958
Things intelligence communication (M2M or IoT) service activation and global company of OneM2M-related business on aggressive investing and has led to the acceleration of change in the ICT market. But a variety of hacking security technology because of the possibility of secure communication (data exposure, theft, modification, deletion, etc.) has been issued as an important requirement. In this paper, we propose a mutual authentication protocol for secure communications chameleon hash based on the M2M environment. The results of performance analysis efficiency is encryption and decryption an average of 0.7%, calculated rate showed good results as compared to the target algorithm, equivalent to a 3%(Average 0.003 seconds) difference, mutual authentication and encryption region by using the key update advantage of ECC(Elliptic Curve Cryptography)based Chameleon hash function is signed of the operational efficiency, using a collision message verifiable properties demonstrated strong security of the communication section.
Lightweight DTLS Message Authentication Based on a Hash Tree
Lee, Boo-Hyung ; Lee, Sung-Bum ; Moon, Ji-Yeon ; Lee, Jong-Hyouk ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1969~1975
DOI : 10.7840/kics.2015.40.10.1969
The Internet of Things (IoT), in which resource constrained devices communicate with each other, requires a lightweight security protocol. In this paper, we propose a new message authentication scheme using a hash tree for lightweight message authentication in the Datagram Transport Layer Security (DTLS) protocol. The proposed scheme provides lightweight secure operations compared with those of the DTLS protocol. Besides, it provides more suitable performance than the DTLS protocol for an IoT environment, thanks to the reduced use of message authentication code.
Video Streaming Receiver with Token Bucket Automatic Parameter Setting Scheme by Video Information File needing Successful Acknowledge Character
Lee, Hyun-no ; Kim, Dong-hoi ; Nam, Boo-hee ; Park, Seung-young ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1976~1985
DOI : 10.7840/kics.2015.40.10.1976
The amount of packets in palyout buffer of video streaming receiver can be changed by network condition, and saturated and exhausted by the delay and jitter. Especially, if the amount of incoming video traffic exceeds the maximum allowed playout buffer, buffer overflow problem can be generated. It makes the deterioration of video image and the discontinuity of playout by skip phenomenon. Also, if the incoming packets are delayed by network confusion, the stop phenomenon of video image is made by buffering due to buffer underflow problem. To solve these problems, this paper proposes the video streaming receiver with token bucket scheme which automatically establishes the important parameters like token generation rate r and bucket maximum capacity c adapting to the pattern of video packets. The simulation results using network simulator-2 (NS-2) and joint scalable video model (JSVM) show that the proposed token bucket scheme with automatic establishment parameter provides better performance than the existing token bucket scheme with manual establishment parameter in terms of the generation number of overflow and underflow, packer loss rate, and peak signal to noise ratio (PSNR) in three test video sequences.
Resource and Power Allocation Method for Device-to-Device Communications in a Multicell Network
Kang, Gil-Mo ; Shin, Oh-Soon ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1986~1993
DOI : 10.7840/kics.2015.40.10.1986
We investigate the optimal resource and power allocation for device-to-device (D2D) communications in a multicell environment. When D2D links reuse the cellular radio resources, each D2D user will interfere with a cellular link and other D2D links, in its own cell as well as in adjacent cells. Under such situation, we propose a coordinated resource allocation scheme that can handle the intercell interferences as well as the intracell interference. For a given resource allocation, we also formulate a power optimization problem and present an algorithm for finding the optimal solution. The resource and power allocation algorithms are designed to maximize the achievable rate of the D2D link, while limiting the generated interference to the cellular link. The performance of the proposed algorithms is evaluated through simulations in a multicell environment. Numerical results are presented to verify the coordination gain in the resource and power allocation.
Study on Fraud and SIM Box Fraud Detection Method in VoIP Networks
Lee, Jung-won ; Eom, Jong-hoon ; Park, Ta-hum ; Kim, Sung-ho ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 1994~2005
DOI : 10.7840/kics.2015.40.10.1994
Voice over IP (VoIP) is a technology for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks. Instead of being transmitted over a circuit-switched network, however, the digital information is packetized, and transmission occurs in the form of IP packets over a packet-switched network which consist of several layers of computers. VoIP Service that used the various techniques has many advantages such as a voice Service, multimedia and additional service with cheap cost and so on. But the various frauds arises using VoIP because VoIP has the existing vulnerabilities at the Internet and based on complex technologies, which in turn, involve different components, protocols, and interfaces. According to research results, during in 2012, 46 % of fraud calls being made in VoIP. The revenue loss is considerable by fraud call. Among we will analyze for Toll Bypass Fraud by the SIM Box that occurs mainly on the international call, and propose the measures that can detect. Typically, proposed solutions to detect Toll Bypass fraud used DPI(Deep Packet Inspection) based on a variety of detection methods that using the Signature or statistical information, but Fraudster has used a number of countermeasures to avoid it as well. Particularly a Fraudster used countermeasure that encrypt VoIP Call Setup/Termination of SIP Signal or voice and both. This paper proposes the solution that is identifying equipment of Toll Bypass fraud using those countermeasures. Through feature of Voice traffic analysis, to detect involved equipment, and those behavior analysis to identifying SIM Box or Service Sever of VoIP Service Providers.
Design of a Multi-Protocol Gateway System Based on Low Power Wireless Communications
Hong, Sung-IL ; Lin, Chi-Ho ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 2006~2013
DOI : 10.7840/kics.2015.40.10.2006
In this paper we propose a multi-protocol gateway system based on low power wireless communications. The proposed multi-protocol gateway system was designed to allow real-time monitoring and control of the on-site situation through wired and wireless networks by gathering information for streetlight power control and environmental monitoring. The sensing data using multi-sensors with composite processing that selectively used wired or wireless communication (e.g., CDMA, Ethernet (TCP/IP), GPS, etc.) were designed to act as intermediaries that transmitted to the main server through ZigBee. Inaddition, they were designed by separating a CPU board and baseboard to ensure low maintenance cost and ease of hardware replacement. The proposed multi-protocol gateway system`s power, impact, continuous operation stability, and immunity test results obtained a normal operation success rate of over 95% and normal continuous operation results. Moreover, in the voltage drop test, instantaneous immunity test, and conductive RF electromagnetic field immunity test, it obtained an average rating result of "A".
Symmetric Inter-Communication Scheme among Mobile Objects in Wireless Sensor Networks
Kim, Sangdae ; Kim, Cheonyong ; Cho, Hyunchong ; Yang, Taehun ; Kim, Sang-Ha ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 2014~2025
DOI : 10.7840/kics.2015.40.10.2014
Wireless Sensor Networks (WSNs) are special network which has purpose of usage for gathering information of certain area and observing situation. WSNs consist of small nodes with sensing event such as temperature, movement or certain objects. The sensor has the capabilities to collect data and route data back to the sink. The sensors route data either to other sensors or back to a sink in one direction. That is, traditional WSNs communicate asymmetrically. However, under the new paradigm of the Internet of Things (IoTs) or Cyber Physical system (CPS), WSNs have potential to be used as important area. So, more research is necessary to communicate with each moving objects symmetrically in WSNs. In this paper, we proposed symmetric communication scheme among mobile objects in wireless sensor network. Simulation results show that our scheme is superior th the existing ones in terms of energy consumption and transmission success ratio.
Opportunistic Multipath Routing Scheme for Guaranteeing End-to-End Reliability in Large-Scale Wireless Sensor Networks
Kim, Cheonyong ; Jung, Kwansoo ; Kim, Sang-Ha ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 2026~2034
DOI : 10.7840/kics.2015.40.10.2026
Wireless sensor networks (WSNs) consist of a lot of sensor nodes having limited transmission range. So multi-hop transmission is used for communication among nodes but the multi-hop transmission degrade the end-to-end reliability. Multipath routing and opportunistic routing are typical approaches for guaranteeing end-to-end reliability in WSNs. The existing protocols improve the reliability effectively in small networks but they suffer from rapid performance degradation in large networks. In this paper, we propose the opportunistic multipath routing protocol for guaranteeing end-to-end reliability in large WSNs. Applying multipath routing and opportunistic routing simultaneously is very hard because their conflicting routing features. The proposed protocol applies these approaches simultaneously by section-based routing thereby enhancing end-to-end reliability. Additionally, the proposed protocol guarantees required reliability by the concept of section reliability. The section reliability over a certain level might satisfy required end-to-end reliability. Our simulation results show that the proposed protocol is more suitable for guaranteeing reliability than existing protocols in large-scale WSNs.
Bio-Inspired Resource Allocation Scheme for Multi-Hop Networks
Kim, Young-Jae ; Jung, Ji-Young ; Choi, Hyun-Ho ; Han, Myoung-Hun ; Park, Chan-Yi ; Lee, Jung-Ryun ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 2035~2046
DOI : 10.7840/kics.2015.40.10.2035
Recently, researches on resource allocation algorithms operating in a distributed way are widely conducted because of the increasing number of network nodes and the rapidly changing the network environment. In this paper, we propose Multi-Hop DESYNC(MH DESYNC), that is bio-inspired TDMA-based resource allocation scheme operating in a distributed manner in multi-hop networks. In this paper, we define a frame structure for the proposed MH DESYNC algorithm and firing message structure which is a reference for resource allocation and propose the related operating procedures. We show that MH DSYNC can resolve the hidden-node problem effectively and verify that each node shares resources fairly among its neighboring nodes. Through simulation evaluations, it is shown that MH DESYNC algorithm works well in a multi-hop networks. Furthermore, results show that MH DESYNC algorithm achieves better performance than CSMA/CA algorithm in terms of throughput.
IoT Platform for Network Service Self-Configuration Based on Data Flow
Kwon, Kideok ; Yoo, Younghwan ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 2047~2053
DOI : 10.7840/kics.2015.40.10.2047
Our research proposese an IoT Broker (gateway) platform which considers the both sides of a service developer and a user. The platform associates the devices around us with virtual-entities and infers the owner of the devices through the ontology scheme. These functionalities can make the service developer easily design a new service. For the user, the service can be automatically installed and deployed under this platform. We also make it possible for the IoT broker to be plugged-in by integrating various communication platforms and protocols into that platform. Our expreriment with the AllJoyn plug-in on Node-RED substantiated that various service flows can be easily deployed and work on our platform.
Design of Distributed Node Scheduling Scheme Inspired by Gene Regulatory Networks for Wireless Sensor Networks
Byun, Heejung ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 2054~2061
DOI : 10.7840/kics.2015.40.10.2054
Biologically inspired modeling techniques have received considerable attention for their robustness, scalability, and adaptability with simple local interactions and limited information. Among these modeling techniques, Gene Regulatory Networks (GRNs) play a central role in understanding natural evolution and the development of biological organisms from cells. In this paper, we apply GRN principles to the WSN system and propose a new GRN model for decentralized node scheduling design to achieve energy balancing while meeting delay requirements. Through this scheme, each sensor node schedules its state autonomously in response to gene expression and protein concentration, which are controlled by the proposed GRN-inspired node scheduling model. Simulation results indicate that the proposed scheme achieves superior performance with energy balancing as well as desirable delay compared with other well-known schemes.
Indoor Positioning Algorithm using Image Sensors
Huynh, Phat ; Yoo, Myungsik ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 2062~2064
DOI : 10.7840/kics.2015.40.10.2062
In this paper, we propose indoor positioning algorithm performed at the image sensor equipped in mobile station, which receives the light signal from LED panels. To evaluate the performance of positioning algorithm, we consider the ambient noise existing indoor environment, and it is found that the proposed algorithm estimates the position of mobile station with high accuracy regardless of existence of ambient noise.
Performance Analysis of Visible Light Communication System Using Rolling Shutter CMOS Sensor
Do, Trong-Hop ; Yoo, Myungsik ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 2065~2067
DOI : 10.7840/kics.2015.40.10.2065
In this paper, we analyze the performance of visible light communication system using rolling shutter CMOS sensor. For analysis, the effect of ISI (Inter-symbol Interference) on visible communication has been formulated. We validate our analysis through computer simulations.
Attendance Management System Using Indoor Localization Techniques
Seo, Dongin ; Ahn, Daye ; Ha, Rhan ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 2068~2079
DOI : 10.7840/kics.2015.40.10.2068
Recently, interesting in flexible working has been increased, and some central government and large companies are conducting flexible working. With the conducting of flexible working, workers are able to get a convenience but the cost of managing is increased. In this paper, we suggest a method of reducing the cost and managing efficiently. Our study determines the position of the workers using indoor localization techniques through the Wi-Fi fingerprint and smartphone, and records the office hours. The previous time and attendance systems have to install attendance recording device(e.g. Fingerprint Attendance System, RFID Card Attendance System) and are needed to manipulate manually. Our system doesn`t need to install extra devices, and also doesn`t need to manipulate manually. Our system automatically records the office hours. Also most of previous time and attendance systems have another weakness. They only record data when workers start and stop work. But our system exactly records office hours for each workplaces. In this paper, We introduce an effective time and attendance system in variety flexible working. Our experiments shows that our system workers` detected office hours accurately. The accuracy of our time and attendance system was 98.7%.
Disparity Vector Derivation Method for Texture-Video-First-Coding Modes of 3D Video Coding Standards
Kang, Je-Won ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 2080~2089
DOI : 10.7840/kics.2015.40.10.2080
In 3D video compression, a disparity vector (DV) pointing a corresponding block position in an adjacent view is a key coding tool to exploit statistical correlation in multi-view videos. In this paper, neighboring block-based disparity vector (NBDV) is shown with detail algorithm descriptions and coding performance analysis. The proposed method derives a DV from disparity motion vector information, obtained from spatially and temporally neighboring blocks, and provides a significant coding gain about 20% BD-rate saving in a texture-video-first-coding scheme. The proposed DV derivation method is adopted into the recent 3D video coding standards such as 3D-AVC and 3D-HEVC as the state-of-the-art DV derivation method.
Face Tracking Combining Active Contour Model and Color-Based Particle Filter
Kim, Jin-Yul ; Jeong, Jae-Ki ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 2090~2101
DOI : 10.7840/kics.2015.40.10.2090
We propose a robust tracking method that combines the merits of ACM(active contour model) and the color-based PF(particle filter), effectively. In the proposed method, PF and ACM track the color distribution and the contour of the target, respectively, and Decision part merges the estimate results from the two trackers to determine the position and scale of the target and to update the target model. By controlling the internal energy of ACM based on the estimate of the position and scale from PF tracker, we can prevent the snake pointers from falsely converging to the background clutters. We appled the proposed method to track the head of person in video and have conducted computer experiments to analyze the errors of the estimated position and scale.
A Positioning Algorithm Using Virtual Reference for Accuracy Improvement in Relay-Based Navigation System
Lee, Kyuman ; Lim, Jaesung ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 10, 2015, Pages 2102~2112
DOI : 10.7840/kics.2015.40.10.2102
In this paper, we propose a new positioning scheme for accuracy improvement of Relay-based Navigation System. The conventional relay-based system occurs larger vertical error than horizontal one due to structural characteristics that positioning references are located toward same direction and a location of user is estimated by triangulation technique. In the proposed positioning scheme, the user position is reestimated using an additional virtual reference which is generated based on position information of reference stations in navigation signals and estimated initial user position. The nearest reference station from the estimated user position is selected as a virtual reference to minimize the effect of geometrical factor. The vertical error decreases by using reference points on multi planes, therefore, accurate positioning is possible than the conventional scheme. We demonstrated that the accuracy of a user is improved through simulation results.