In this paper, a human detection method is developed. An appearance based detector and a motion based detector are proposed respectively. A multi scale block histogram of template feature (MB-HOT) is used to detect human by the appearance. It integrates the gray value information and the gradient value information, and represents the relationship of three blocks. Experiment on INRIA dataset shows that this feature is more discriminative than other features, such as histogram of orientation gradient (HOG). A motion based feature is also proposed to capture the relative motion of human body. This feature is calculated in optical flow domain and experimental result in our dataset shows that this feature outperforms other motion based features. The detection responses obtained by two features are combined to reduce the false detection. Graphic process unit (GPU) based implementation is proposed to accelerate the calculation of two features, and make it suitable for real time applications.

This manuscript introduces a pointing interface for a tabletop display with a reflex in eye-hand coordination. The reflex is a natural response to inconsistency between kinetic information of a mouse and visual feedback of the mouse cursor. The reflex yields information on which side the user sees the screen from, so that the screen coordinates are aligned with the user's position.

This paper describes a spatial fading emulator based on Clarke's model that can evaluate spatial correlation characteristics between signals received by handset antennas including human-body effect under emulated multipath propagation environments. The proposed model is composed of scatterers, phase-shifters and attenuators. The scatterers are located at equal intervals on the circumference of a circle. Phase shifters and attenuators in a control circuit are used to control the phase and amplitude of each wave radiated from the scatterers in order to emulate multi-path propagation environments, such as Rayleigh or Nakagami-Rice distribution, to be generated at their center. In this paper, the maximum distance between receiving antennas that could be used to evaluate spatial correlation characteristics between antennas was investigated experimentally. The measurement results show that 15 scatterers with a radius of 1.5 m are sufficient to evaluate spatial correlation characteristics within the branch separation of 1.7 λ when parallel dipole antennas are used as receiving antennas.

The noise performances under AWGN channel of the IF-derivative and the quadrature differential FM discriminators, which are widely utilized in modern low power wireless radios, are analyzed and compared. The analysis relies upon the time-domain multi-sinusoidal representation of the noise that facilitates accurate and closed-form analytical SNR characteristics. Derivation of the SNR equations is detailed and discussion based on the analysis results is given to provide insights into the discriminators' performance limitation where it is demonstrated that the differential scheme is considerably more advantageous. Simulated SNR characteristics of practical continuous-phase frequency shift keying (CPFSK) systems using both the FM discriminators are presented as analysis verification.

A previous study proposed a downlink scheduling of real time variable rate (RT-VR), non real time variable rate (NRT-VR), and best effort (BE) traffic forwarding classes[1] to support QoS of the WiMax network. However, the study did not consider scheduling extended real time variable rate (ERT-VR) service, which defines the additional requirement of jitter performance when compared with RT-VR service. This article studies the supplementing function in ERT-VR service to complete QoS scheduling of downlink traffic in the WiMax network. Simulation results indicate that the proposed scheme not only satisfies delay time, but also guarantees the jitter requirement of ERT-VR traffic.

CMOS SoCs can reduce power consumption by adopting voltage scaling (VS) technologies, where the level converter (LC) is required between voltage domains to avoid dc current. However, the LC often induces high delay penalty and usually results in non-balanced rise and fall delays. Therefore, the performance of the LC strongly affects the effectiveness of VS technologies. In this paper, heuristic sizing methodology for designing a state-of-the-art LC is developed and proposed. Using the proposed methodology, we can design the LC to achieve high performance with balanced rise and fall delay times in a deterministic way.

A characteristic-based constrained interpolation profile (CIP) method for solving three-dimensional, time-dependent Maxwell's equations is successfully developed. It is utilized to solve one-dimensional wave equations in the formulation of the Maxwell's equations. Calculation procedure of the CIP method for three-dimensional scattering analysis is described in details. Update equations for boundary conditions of a perfectly conducting (PEC) interface and a dielectric interface are formulated and obtained in explicit forms. Numerical analyses of electromagnetic scatterings of PEC sphere, dielectric sphere and PEC cube are performed and the scattering coefficient is calculated and compared with the Mie's analytic results. As a result, the scattering coefficients show good agreement with the Mie's results, which demonstrates the validity of the CIP method and the formulated update equations. It is also shown that the phase of the scattering coefficients determined by the CIP method are slightly more accurate than that of the FDTD method.

This paper attempts to analyze theoretically the propagation characteristics in the transverse section of upper body to support on-body wireless communications. The analytical estimation assumes that the human body is structured as a lossy-dielectric circular cylinder with infinite length that consists of the 2/3-muscle equivalent uniform tissue. Each scattering electric field formulation inside and outside of the cylinder is derived for scattering characteristics in the propagation environment including the human body when the source current has the vertical direction to the cylinder surface or the horizontal direction to the cylinder axis. In order to confirm the reliability of the formulation, total electric field distributions at 2.45 GHz are compared with the results by the finite-difference time-domain (FDTD) method. In each current direction, general scattering characteristics and the influence on the total propagation are estimated. Furthermore, from scattering and total electric field intensities evaluated with the variations of operating frequency, radius of the human body, and distance between a source and the human body, propagation characteristics are investigated to assist in the design of a device for on-body propagation channel with the upper body.

In this paper, we study the performance of base station (BS) cooperation for downlink transmission. Based on a modified Wyner multicell model, an opportunistic intra cell scheduling scheme is proposed. Then, we derive a closed-form expression for the sum-rate capacity of the proposed scheme in the Rayleigh flat-fading channel. Also, we prove that the opportunistic scheme can be regarded as providing a downlink beam-forming scheme to achieve a tighter lower bound for the downlink sum rate capacity. Numerical results confirm our theoretical analysis.

In this paper, we analyze the performance of the 21 Alamouti scheme suggested by Alamouti, composed of the transmit space-time code and the simple linear decoding processing, in perfectly time-varying and spatially correlated channels. We derive the closed-form probability density function (PDF) of output signal-to-noise ratio (SNR) and outage probability of the Alamouti scheme as a function of spatial correlation coefficient in the consideration of no correlation in time. We observe that the performance of the Alamouti scheme is severely degraded when the channels are time-varying and spatially correlated.

The principles for good design of battery-aware voltage scheduling algorithms for both aperiodic and periodic task sets on dynamic voltage scaling (DVS) systems are presented. The proposed algorithms are based on greedy heuristics suggested by several battery characteristics and Lagrange multipliers. To construct the proposed algorithms, we use the battery characteristics in the early stage of scheduling more properly. As a consequence, the proposed algorithms show superior results on synthetic examples of periodic and aperiodic tasks from the task sets which are excerpted from the comparative work, on uni- and multi-processor platforms, respectively. In particular, for some large task sets, the proposed algorithms enable previously unschedulable task sets due to battery exhaustion to be schedulable.

Recently a simple proof of Jury test for complex polynomials was given by the author. In this letter further extended results are presented. Another elementary proof of the Schur stability condition is provided. More importantly it is shown that the stability table can also be used to determine the root distribution of complex polynomials with respect to the unit circle in the complex plane.

Single event transient (SET) effects on original static cascade voltage switch logic (CVSL) exclusive-OR (EX-OR) circuits have been investigated using SPICE. SET simulation results have confirmed that the static CVSL EX-OR circuits have increased tolerance to SET. The static CVSL EX-OR circuit is more than 200 times harder than the conventional CMOS circuit.

A linear model for feedforward ring oscillators (FROs) is developed and oscillator characteristics are analyzed using the model. The model allows prediction of multiple oscillation modes as well as the oscillation frequency of each mode. The prediction agrees well with SPICE simulation results.

A novel Position-Invariant Robust Feature, designated as PIRF, is presented to address the problem of highly dynamic scene recognition. The PIRF is obtained by identifying existing local features (i.e. SIFT) that have a wide baseline visibility within a place (one place contains more than one sequential images). These wide-baseline visible features are then represented as a single PIRF, which is computed as an average of all descriptors associated with the PIRF. Particularly, PIRFs are robust against highly dynamical changes in scene: a single PIRF can be matched correctly against many features from many dynamical images. This paper also describes an approach to using these features for scene recognition. Recognition proceeds by matching an individual PIRF to a set of features from test images, with subsequent majority voting to identify a place with the highest matched PIRF. The PIRF system is trained and tested on 2000+ outdoor omnidirectional images and on COLD datasets. Despite its simplicity, PIRF offers a markedly better rate of recognition for dynamic outdoor scenes (ca. 90%) than the use of other features. Additionally, a robot navigation system based on PIRF (PIRF-Nav) can outperform other incremental topological mapping methods in terms of time (70% less) and memory. The number of PIRFs can be reduced further to reduce the time while retaining high accuracy, which makes it suitable for long-term recognition and localization.

We propose a new channel adaptive distributed video coding algorithm, which is adaptive to time-varying available bitrate and packet loss ratio. The proposed method controls the quantization parameter according to channel condition of especially error-prone mobile channel. Simulation shows that the proposed algorithm outperforms the conventional rate-control-only algorithm.

Proportional fair scheduling attains a graceful trade-off between fairness among users and total system throughput. It is simple to implement in single carrier transmission systems, while changes to a prohibitively complex combinatorial problem for multi-carrier transmission systems. This letter addresses a couple of conditions that approximate multi-carrier proportional fair scheduling (MCPF) as carrier-by-carrier proportional fair scheduling (CCPF), which has much lower complexity than MCPF. Numerical results show that the proportional fairness metric of CCPF approaches to that of MCPF for those conditions.

In this paper we introduce a new framework of audio processing, which is essential to achieve a trigger-free speech interface for home appliances. If the speech interface works continually in real environments, it must extract occasional voice commands and reject everything else. It is extremely important to reduce the number of false alarms because the number of irrelevant inputs is much larger than the number of voice commands even for heavy users of appliances. The framework, called Intentional Voice Command Detection, is based on voice activity detection, but enhanced by various speech/audio processing techniques such as emotion recognition. The effectiveness of the proposed framework is evaluated using a newly-collected large-scale corpus. The advantages of combining various features were tested and confirmed, and the simple LDA-based classifier demonstrated acceptable performance. The effectiveness of various methods of user adaptation is also discussed.

In this paper, we present a novel color independent components based SIFT descriptor (termed CIC-SIFT) for object/scene classification. We first learn an efficient color transformation matrix based on independent component analysis (ICA), which is adaptive to each category in a database. The ICA-based color transformation can enhance contrast between the objects and the background in an image. Then we compute CIC-SIFT descriptors over all three transformed color independent components. Since the ICA-based color transformation can boost the objects and suppress the background, the proposed CIC-SIFT can extract more effective and discriminative local features for object/scene classification. The comparison is performed among seven SIFT descriptors, and the experimental classification results show that our proposed CIC-SIFT is superior to other conventional SIFT descriptors.

Break arcs are generated between electrical contacts in a DC 42 V resistive circuit. Contact materials are Ag/SnO2 and Ag/ZnO. Circuit current when contacts are closed is varied from 5 A to 21 A. The radial magnetic field to drive break arcs is formed between the contact gap with a permanent magnet embedded in the cathode. The arc motion is observed with a high-speed camera. Experimental results with the magnet are compared with those without the magnet. Following results are shown. Similar experimental results to pure silver contacts are obtained for Ag/SnO2 and Ag/ZnO contact pairs. The rotational motion of the break arcs and the shortening effect of the arc duration are confirmed. The ring-shaped, wide and uniform traces are observed on the contact surfaces after break operations. This result shows the prevention effect of local erosion of electrical contacts and the reduction of total amount of contact erosion. The rotational frequency f is increased with the increase of the arc current Iarc. These results for Ag/SnO2 and Ag/ZnO contact pairs are similar to the results for pure silver contacts in our previous experiments. The rotational frequency of the break arc for the Ag/SnO2 and Ag/ZnO contacts is lower than that for the pure silver contacts.