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Nguyen T.D.,Chonnam National University | Kim J.H.,Chonnam National University | Kim S.H.,Chonnam National University | Yang H.J.,Chonnam National University | And 3 more authors.
ETRI Journal | Year: 2012

A novel interaction method for mobile phones using their built-in cameras is presented. By estimating the path connecting the center points of frames captured by the camera phone, objects of interest can be easily extracted and recognized. To estimate the movement of the mobile phone, corners and corresponding Speeded-Up Robust Features descriptors are used to calculate the spatial transformation parameters between the previous and current frames. These parameters are then used to recalculate the locations of the center points in the previous frame into the current frame. The experiment results obtained from real image sequences show that the proposed system is efficient, flexible, and able to provide accurate and stable results. © 2012 ETRI.


Han Y.-T.,Convergence Components and Material Research Laboratory | Han Y.-T.,Korea Advanced Institute of Science and Technology | Shin J.-U.,Convergence Components and Material Research Laboratory | Park S.-H.,Convergence Components and Material Research Laboratory | And 5 more authors.
ETRI Journal | Year: 2011

This letter presents a polymer 1×2 thermo-optic totalinternal- reflection digital optical switch (TIR-DOS) with an index contrast of 1.5%-Δ operating at low power consumption. The structure of our 1×2 TIR-DOS was created by adding a reflection port to that of a conventional multimode filtering variable optical attenuator. To improve the total-internalreflection efficiency, a heater offset was applied to the crossing region of multimode waveguides of the TIR-DOS. The fabricated 1×2 TIR-DOS shows a low electrical power consumption of 18 mW for an on-off ratio of 35 dB. © 2011 ETRI.


Park J.-W.,Creative and Challenging Research Division | Han S.,Creative and Challenging Research Division | Lee D.,Convergence Components and Materials Research Laboratory | Ryu H.-C.,Creative and Challenging Research Division | And 5 more authors.
ETRI Journal | Year: 2012

A high-speed traveling-wave photodetector (TWPD) with an InGaAs absorber is designed and realized. The bandwidth of the TWPD is measured using electro-optic sampling techniques. The bandwidth is 410 GHz, which shows that the RC limitation is overcome. While the TWPD shows a low responsivity of 0.06 A/W at 1,550 nm, this value can be improved through further optimization of the structure without a sacrifice in bandwidth. © 2012 ETRI.


Kang S.G.,Gyeongsang National University | Chen Z.,Gyeongsang National University | Kim J.Y.,Creative and Challenging Research Division | Bae J.S.,Creative and Challenging Research Division | Lim J.-S.,Gyeongsang National University
IEEE Transactions on Signal Processing | Year: 2011

A simple and straightforward method of constructing higher-level three-dimensional (3-D) signal constellations for a reliable digital communication system is proposed in this paper. The new method expands basic 8-ary constellation into 3-D signal space systematically so that it produces lattice configurations. We also derive accurate closed-form symbol error probability (SEP) of cross-lattice constellations in additive white Gaussian noise (AWGN). It is verified that the theoretical SEPs are almost the same as simulation results. Minimum Euclidean distance (MED) of the higher-level 3-D constellations is increased at least 49% in comparison with quadrature amplitude modulation (QAM). When the number of symbols is 256, the 3-D constellation has around 105% longer MED than the 2-D QAM. Due to increase in MED, the 3-D constellations have much improved error performance compared to the QAM configurations. It is, therefore, considered that the higher-level 3-D constellations are appropriate for high-quality digital communications. © 2011 IEEE.


Doo K.-H.,Advanced Communications Research Laboratory | Yoon B.-Y.,Creative and Challenging Research Division | Lee B.-C.,Advanced Communications Research Laboratory | Lee S.-S.,Advanced Communications Research Laboratory | And 2 more authors.
ETRI Journal | Year: 2012

We propose a flow admission control (FAC) for setting up a wire-speed connection for new flows based on their negotiated bandwidth. It also terminates a flow that does not have a packet transmitted within a certain period determined by the users. The FAC can be used to provide a reliable transmission of user datagram and transmission control protocol applications. If the period of flows can be set to a short time period, we can monitor active flows that carry a packet over networks during the flow period. Such powerful flow management can also be applied to security systems to detect a denial-of-service attack. We implement a network processor called a flow management network processor (FMNP), which is the second generation of the device that supports FAC. It has forty reduced instruction set computer core processors optimized for packet processing. It is fabricated in 65-nm CMOS technology and has a 40-Gbps process performance. We prove that a flow router equipped with an FMNP is better than legacy systems in terms of throughput and packet loss. © 2012 ETRI.


Won S.H.,Creative and Challenging Research Division | Kim S.R.,Creative and Challenging Research Division | Kim J.-I.,Creative and Challenging Research Division
12th IEEE International Conference on Communication Systems 2010, ICCS 2010 | Year: 2010

This paper proposes and evaluates an enhanced layered demodulation (ELD) for improving bit error rate (BER) performance and complexity over conventionally used layered demodulation (LD). The layered modulated and transmitted signals are consisting of base and enhanced layers delivering scalable video coded (SVC) information in wireless media. The new idea proposed in this paper is the way of re-using partially determined survival path metric values of the base layer to make base layer excluded received signal for decoding enhanced layer. Computer simulation shows that ELD, the proposed method shows the same performance for the base layer but good BER improvement with low complexity for excluding regeneration steps used for canceling base layer signal for decoding enhanced layer. © 2010 IEEE.


Cho Y.,Broadcasting and Telecommunications Convergence Research Laboratory | Radha H.,Michigan State University | Seo J.,Broadcasting and Telecommunications Convergence Research Laboratory | Kang J.,Broadcasting and Telecommunications Convergence Research Laboratory | Hong J.,Creative and Challenging Research Division
ETRI Journal | Year: 2010

The overall channel capacity of a multihop wireless path drops progressively over each hop due to the cascading effect of noise and interference. Hence, without optimal rate adaptation, the video quality is expected to degrade significantly at any client located at a far-edge of an ad-hoc network. To overcome this limitation, decoding and forwarding (DF), which fully decodes codewords at each intermediate node, can be employed to provide the best video quality. However, complexity and memory usage for DF are significantly high. Consequently, we propose syndrome-based partial decoding (SPD). In the SPD framework an intermediate node partially decodes a codeword and relays the packet along with its syndromes if the packet is corrupted. We demonstrate the efficacy of the proposed scheme by simulations using actual 802.11b wireless traces. The trace-driven simulations show that the proposed SPD framework, which reduces the overall processing requirements of intermediate nodes, provides reasonably high goodput when compared to simple forwarding and less complexity and memory requirements when compared to DF. Copyright © 2010 ETRI.


Go Y.,Creative and Challenging Research Division | Han G.P.,Creative and Challenging Research Division
2012 International Conference on Information Science and Applications, ICISA 2012 | Year: 2012

In recent years, there has been interest in home-service robots and their usages have been highly evaluated. However, home-service robots could not match expectations of users due to their poor cognitive abilities. There have been various ways to improve robot's usage. Proactive Way could be one of key aspects to make a home-service robot like rich cognitive ability and having intelligence as well as enhancing its service capability. In this paper, we propose the concept of Proactive Space as the Proactive Way. We also present Proactive Space Environment (short of PSE). The proposed PSF is made with situation-aware networks, service models, and a reasoning process. Under PSE, a home-service robot can operate itself with automaticity and provide services at the right time. It could get current situations, select possible candidates of services, reason the right service time and feasible services from candidate services, then show or do the final service to user even if there is no user's explicit order. © 2012 IEEE.


Park J.,Sungkyunkwan University | Lee S.,Sungkyunkwan University | Kim T.,Sungkyunkwan University | Shin J.,Sungkyunkwan University | Won S.H.,Creative and Challenging Research Division
Proceedings - 7th International Conference on Digital Content, Multimedia Technology and Its Applications, IDCTA 2011 | Year: 2011

This paper proposes a low-complexity bit-allocation scheme for video transmission of the scalable extension of H.264/AVC (SVC). The proposed method consists of SVC source-layer encoding and layered forward error correction (FEC) using LDPC channel codes. The experimental results show that the proposed scheme provides similar video quality when comparing with full-search method, but it has much lower computational complexity. Thus, the proposed method is more suitable for the real-time video streaming service. © 2011 AICIT.


Yoon J.,Sungkyunkwan University | Lee S.,Sungkyunkwan University | Shin J.,Sungkyunkwan University | Won S.H.,Creative and Challenging Research Division
Proceedings - 7th International Conference on Digital Content, Multimedia Technology and Its Applications, IDCTA 2011 | Year: 2011

Recently, relay-based cooperative system has drawn much attention. There are several technical components to be considered in this relay system such as multiple antenna schemes, network coding, etc. In this paper, we do a performance analysis using a combination of multiple-input multiple-output (MIMO) techniques and network coding in a wireless relay-based cooperative system having multiple nodes to send data toward one destination via one relay node which performs network coding. For the performance analysis, we derive overall error probability and channel capacity for multi-user uplink relay-based cooperative communication. The results show that the changes among MIMO modes (i.e., spatial multiplexing or diversity mode) at the transmission between source-to-relay or relay-to-destination is useful to maximize system capacity. Also this analysis can decide an optimal switching point of SNR for different MIMO modes in terms of average signal-to-noise ratio (SNR) in order to achieve best performance. Thus, a practical guidance of combined scheme using network coding and MIMO can be derived. © 2011 AICIT.

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