We propose a novel and efficient approach for tracking 2D articulated human body parts. In our approach, the human body is modeled by a graphical model where each part is represented by a node and the relationship between a pair of adjacent parts is indicated by an edge in the graph. Various approaches have been proposed to solve such problems, but efficiency is still a vital problem. We present a new Quick Shift Belief Propagation (QSBP) based approach which benefits from Quick Shift, a simple and efficient mode seeking method, in a part based belief propagation model. The unique aspect of this model is its ability to efficiently discover modes of the underlying marginal probability distribution while preserving the accuracy. This gives QSBP a significant advantage over approaches like Belief Propagation (BP) and Mean Shift Belief Propagation (MSBP). Moreover, we demonstrate the use of QSBP with an action based model; this provides additional advantages of handling self-occlusion and further reducing the search space. We present qualitative and quantitative analysis of the proposed approach with encouraging results.

A resource allocation scheme for multi-access MIMO-OFDM systems in uplink was developed to improve power and spectrum efficiency in the frequency and the space domains [1]. The scheme requires a multi-user detector in the receiver and assumes identical spatial crosscorrelation across all subcarriers for any pair of spatially separable users. However, the multi-user detection device may not exist in the receiver and the identical spatial crosscorrelation assumption may not be valid in some operational scenarios. The paper develops a scheme to remedy these problems for multi-access MIMO-OFDM systems without using multi-user detection techniques and the assumption. The proposed scheme aims at minimizing the total user transmit power while satisfying the required data rate, the maximum transmit power constraint, and the bit error rate of each user. The simulation results are presented to demonstrate the efficacy of the proposed algorithm.

Multi-site MIMO (Multiple Input Multiple Output) is a key technology that will enable next generation cellular networks to achieve high throughput in cell edge areas. However, a multi-site single-user MIMO system is subject to performance degradation in terms of cell throughput due to the expense of additional assignments of radio resources to cell edge user equipment. This paper presents a BS-cooperation scheduling scheme for a multi-site single-user MIMO cellular system. The proposed BS-cooperation scheduling scheme aims to maintain cell throughput while improving cell edge user throughput. The proposed scheme employs two policies with respect to the assignment of radio resource to the user equipment with multi-site connection. One is to control the opportunities for radio resource assignment to user equipment with a multi-site connection to avoid the excessive assignment of radio resources and to maintain cell throughput. The other policy governs the decision as to whether the user equipment operates with a multi-site connection or not, making it possible for the multi-site connection to contribute to the improvement in user throughput in the cell edge areas. The simulation results show that the proposed scheme is effective from the perspective of both cell throughput and cell edge user throughput.

Negative Bias Temperature Instability (NBTI) is one of the major reliability problems in advanced technologies. NBTI causes threshold voltage shift in a PMOS transistor. When the PMOS transistor is biased to negative voltage, threshold voltage shifts to negatively. On the other hand, the threshold voltage recovers if the PMOS transistor is positively biased. In an SRAM cell, due to NBTI, threshold voltage degrades in the load PMOS transistors. The degradation has the impact on Static Noise Margin (SNM), which is a measure of read stability of a 6-T SRAM cell. In this paper, we discuss the relationship between NBTI degradation in an SRAM cell and the dynamic stress and recovery condition. There are two important characteristics. One is a stress probability, which is defined as the rate that the PMOS transistor is negatively biased. The other is a stress and recovery cycle, which is defined as the switching interval of an SRAM value. In our observations, in order to mitigate the NBTI degradation, the stress probability should be small and the stress and recovery cycle should be shorter than 10 msec. Based on the observations, we propose a novel cell-flipping technique, which makes the stress probability close to 50%. In addition, we show results of the case studies, which apply the cell-flipping technique to register file and cache memories.

We propose a compact matrix-switch-based hierarchical optical cross-connect (HOXC) architecture that effectively handles the colorless waveband add/drop ratio restriction so as to realize switch scale reduction. In order to implement the colorless waveband add/drop function, we develop a wavelength MUX/DMUX that can be commonly used by different wavebands. We prove that the switch scale of the proposed HOXC is much smaller than that of conventional single-layer optical cross-connects (OXCs) and a typical HOXC. Furthermore, we introduce a prototype system based on the proposed architecture that utilizes integrated novel wavelength MUXs/DMUXs. Transmission experiments prove its technical feasibility.

In deep-submicron era, wire delay is becoming a bottleneck while pursuing even higher system clock speed. Several distributed register (DR) architectures have been proposed to cope with this problem by keeping most wires local. In this article, we propose a new resource-constrained communication synthesis algorithm for optimizing both inter-island connections (IICs) and latency targeting on distributed register-file microarchitecture (DRFM). The experimental results show that up to 24.7% and 12.7% reduction on IIC and latency can be achieved respectively as compared to the previous work.

The sensing scheme based on the generalized likelihood ratio test (GLRT) technique has attracted a lot of research interest in the field of cognitive radios (CR). Although its potential advantages in detecting correlated primary signal have been illustrated in prior work, no theoretical analysis of the positive effects of the correlation has appeared in the literature. In this letter, we derive the theoretical false-alarm and detection probabilities of GLRT detector. The theoretical analysis shows that, in the low signal-to-noise ratio (SNR) region, the detector's performance can be improved by exploiting the high correlations between the primary signal samples. The conclusions of the analysis are verified by numerical simulation results.

A method of estimating dual primitives in a textural image is proposed. This method is based on the Primitive, Grain, and Point Configuration (PGPC) texture model, which regards a texture as an arrangement of grains derived from one or a few primitives. Appropriate primitives can be represented by morphological structuring elements estimated from a texture. Conventional primitive estimation methods estimate only one primitive from each textural image. However, they do not work well on textural images that contain more than one basic structure, since two or more types of grain cannot be generated from only one primitive. The proposed method simultaneously estimates two optimal structuring elements of a texture. The experimental results show that the proposed method provides more representative estimations than the conventional method.

The excessive memory access required to perform motion compensation when decoding compressed video is one of the main limitations in improving the performance of an H.264/AVC decoder. This paper proposes an H.264/AVC decoder that employs three techniques to reduce external memory access events: efficient distribution of reference frame data, on-chip cache memory, and frame memory recompression. The distribution of reference frame data is optimized to reduce the number of row activations during SDRAM access. The novel cache organization is proposed to simplify tag comparisons and ease the access to consecutive 4×4 blocks. A recompression algorithm is modified to improve compression efficiency by using unused storage space in neighboring blocks as well as the correlation with the neighboring pixels stored in the cache. Experimental results show that the three techniques together reduce external memory access time by an average of 90%, which is 16% better than the improvements achieved by previous work. Efficiency of the frame memory recompression algorithm is improved with a 32×32 cache, resulting in a PSNR improvement of 0.371 dB. The H.264/AVC decoder with the three techniques is fabricated and implemented as an ASIC using 0.18 µm technology.

By converting the expression values of each sample into the corresponding rank values, the rank-based approach enables the direct integration of multiple microarray data produced by different laboratories and/or different techniques. In this study, we verify through statistical and experimental methods that informative genes can be extracted from multiple microarray data integrated by the rank-based approach (briefly, integrated rank-based microarray data). First, after showing that a nonparametric technique can be used effectively as a scoring metric for rank-based microarray data, we prove that the scoring results from integrated rank-based microarray data are statistically significant. Next, through experimental comparisons, we show that the informative genes from integrated rank-based microarray data are statistically more significant than those of single-microarray data. In addition, by comparing the lists of informative genes extracted from experimental data, we show that the rank-based data integration method extracts more significant genes than the z-score-based normalization technique or the rank products technique. Public cancer microarray data were used for our experiments and the marker genes list from the CGAP database was used to compare the extracted genes. The GO database and the GSEA method were also used to analyze the functionalities of the extracted genes.

Mobile operators need to migrate from 2G to 3G networks in a cost-effective manner. Cognitive radio systems are currently being investigated as a promising solution to achieve spectrum efficiency by allowing coexistence of unlicensed (secondary) networks and licensed (primary) networks. However, conventional mechanisms to operate these systems incur additional complexity and fail to maximize network performance. In this paper, we propose a pilot sensing and frequency selection method with low complexity for OFDMA-based cognitive radio systems. Subject to the interference constraints imposed by the primary network, capacity maximization problems involving both up-link and down-link connections are considered for overall network performance improvement. The throughput and outage probability of the proposed method are evaluated by simulations. Our proposed method shows outstanding performance if the channel varies frequently in the primary network and the frequency reuse factor of the primary network is high.

The Internet is an extremely convenient network and has become one of the key infrastructures for daily life. However, it suffers from three serious problems; its structure does not suit traffic centralization, its power consumption is rapidly increasing, and its round-trip time (RTT) and delay jitter are large. This paper proposes an extremely energy efficient layer-3 network architecture for the future Internet. It combines the Service Cloud with the Cloud Router and application servers, with the Optical Aggregation Network realized by optical circuit switches, wavelength-converters, and wavelength-multiplexers/demultiplexers. User IP packets are aggregated and transferred through the Optical Aggregation Network to Cloud transparently. The proposed network scheme realizes a network structure well suited to traffic centralization, reduces the power consumption to 1/20-1/30 compared to the existing Internet, reduces the RTT and delay jitter due to its simplicity, and offers easy migration from the existing Internet.

In multi-hop wireless networks, the transmitted signal is generally forwarded over several relay terminals. So, the quality of communications is degraded due to these re-transmissions over fading channels in relay terminals. Basically, the conventional cooperative relaying scheme based on cyclic delay diversity (CDD) reduces this degradation because this scheme could have numerous relay terminals which simultaneously transmit the signals. However, we cannot obtain the maximum diversity gain because of the re-transmission without considering relay channel environments. In this letter, to overcome the decreased performance, we propose an adaptive decode-and-forward (DF) relaying scheme based on CDD which uses cyclic redundancy check (CRC) code. Simulation results show that the proposed scheme provides more improvement in error performance than the conventional schemes in multi-hop networks.

Dicode partial response signaling system over inductively-coupled channel has been developed to achieve higher data rate than self-resonant frequencies of inductors. The developed system operates at five times higher data rates than conventional systems with the same inductor. A current-mode equalization in the transmitter designed in a 90-nm CMOS successfully reshapes waveforms to obtain dicode signals at the receiver. For a 5-Gb/s signaling through the coupled inductors with a 120-µm diameter and a 120-µm distance, 20-mV eye opening was observed. The power consumption value of the transmitter was 58 mW at the 5-Gb/s operation.

A novel charge-recovery logic structure called Pulse Boost Logic (PBL) is proposed in this paper. PBL is a high-speed low-energy-dissipation charge-recovery logic with dual-rail evaluation tree structure. It is driven by 2-phase non-overlap clock, and requires no DC power supply. PBL belongs to boost logic family, which includes boost logic, enhanced boost logic and subthreshold boost logic. In this paper, PBL has been compared with other charge-recovery logic technologies. To demonstrate the performance of PBL structure, a 4-bit pipeline multiplier is designed and fabricated with 0.18 µm CMOS process technology. The simulation results indicate that the 4-bit multiplier can work at a frequency of 1.8 GHz, while the measurement of test chip is at operation frequency of 161 MHz, and the power dissipation at 161 MHz is 772 µW.

Various low power technologies have been developed and applied to LSIs from the point of device and circuit design. A lot more CPU cores as well as function IPs are integrated on a single chip LSI today. Therefore, not only the device and circuit low power technologies, but software power control technologies are becoming more important to reduce active power of application systems. This paper overviews the low power technologies and defines power management platform as a combination of hardware functions and software programming interface. This paper discusses importance of the power management platform and direction of its development.

We propose a packet-based inverse multiplexing method to allow scalable network access with a bigger-pipe physical interface. The method is based on aggregation at the physical layer (APL) that fragments an original packet-flow and distributes the fragments among an adequate numbers of physical links or networks. It allows us to share wavelengths and/or bandwidth resources in optical networks. Its technical feasibility at the speed of newly standardized 100 Gb/s Ethernet (100 GbE) is successfully evaluated by implementing the inverse multiplexing logic functions on a prototype board. We demonstrate super-high-definition video streaming and huge file transfer by transmitting 100 GbE MAC frames over multiple 10 GbE physical links via inverse multiplexing.

In this paper, we show the recent progress of photonic network technologies for the new generation network (NWGN). The NWGN is based on new design concepts that look beyond the next generation network (NGN) and the Internet. The NWGN will maintain the sustainability of our prosperous civilization and help resolve various social issues and problems by the use of information and communication technologies. In order to realize the NWGN, many novel technologies in the physical layer are required, in addition to technologies in the network control layer. Examples of cutting-edge physical layer technologies required to realize the NWGN include a terabit/s/port or greater ultra-wideband optical packet switching system, a modulation-format-free optical packet switching (OPS) node, a hybrid optoelectronic packet switching node, a packet-based reconfigurable optical add/drop multiplexer (ROADM) system, an optical packet and circuit integrated node system, and optical buffering technologies.

This letter introduces a blind minimum interference symbol synchronization for orthogonal frequency-division multiplexing (OFDM) systems based on the cyclic prefix (CP). The basic idea of our contribution is to obtain an estimate of the channel-tap powers from the correlation characteristics of the CP. Based on the estimate of the channel-tap powers, a minimum interference metric is proposed. The proposed algorithm has low complexity and can be used to cope with long inter-symbol-interference (ISI) channels with length up to twice the CP length.

Efficient resource allocation for delay-sensitive traffic, such as telephony and video streaming, in Orthogonal Frequency Division Multiple Access (OFDMA) networks is needed to increase system performance. In our system, users try to achieve a low queuing delay and buffer space usage by competing for transmission over the subchannels. We formulate this problem as a bargaining game and use the Nash Bargaining Solution (NBS) to realize a fair and efficient subchannel allocation for the users. Simulation results show performance improvements, with regard to packet dropping and delay distribution, over other algorithms.