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A device‐free human counting (DFC) algorithm that uses fine‐grained subcarrier information from WiFi devices, called channel state information (CSI), to count the number of people in indoor environments is proposed. The DFC algorithm extracts the features of average attenuation and variation of CSI amplitudes caused by human motions, and puts the features into a training process to improve the counting accuracy. Through a bootstrapping process, the DFC can estimate the number of people standing in the middle of a WiFi link by constructing a probability model with the CSI signals at a receiver side. With this human counting capability, the DFC can support the efficient monitoring and automatic control of electrical devices (e.g. air conditioner, heater, bulb, and beam projector) indoors. Through a real implementation and experiments, it is shown that the DFC algorithm outperforms the state‐of‐the‐art DFC algorithm based on RSSI in indoor environments with human mobility. For a dynamic‐target case in a meeting room, for example, DFC can predict the number of people in an indoor space with an accuracy about 98% at best.

In this paper, we propose an adaptive backstepping controller to control the exact position and orientation of a remotely operated underwater vehicle with parametric model uncertainty. To further improve the angular velocity control precision of each thruster, a phase locked loop (PLL) controller has been added to the backstepping controller. A comparison of two backstepping controllers with and without the PLL control loop has been performed using simulations and experiments. The test results showed that the tracking performance could be improved by using the PLL control loop in the proposed adaptive backstepping controller.

We propose a stable CV-SLAM (Ceiling Vision based Simultaneous Localization and Mapping) technique, which uses both circle and corner features as landmarks in the scene and improves the process stability using saliency measurement. It provides a method which utilizes different feature detection algorithms to detect various key points. And then we measure saliency strength of every points to pick out more stable feature points and generate a hybrid map based on Delaunay triangles among these points. Moreover, we complete SLAM using an extended Kalman filter(EKF), which is fundament for robotic SLAM. Simulation results show the effects of proposed methods.

This paper presents the crescent-shaped slot antenna loading of a circular patch that greatly enhances a 3 dB axial-ratio (AR) bandwidth. A bent feeding line was introduced and attached to a 50- &Omega, microstrip feed line to achieve circular polarization operation. By loading the circular patch into a crescent-shaped slot at a proper position, the 3 dB AR bandwidth is considerably broadened. An antenna prototype with overall dimensions of 50.8 &times, 50.8 &times, 0.5 mm 3 is experimentally demonstrated. Measurement results of the fabricated antenna showed a wide &minus, 10 dB reflection bandwidth of 92.33% (1.79&ndash, 4.86 GHz) and a broad 3 dB AR bandwidth of 84.40% (1.89&ndash, 4.65 GHz). The measured peak gain of the antenna was approximately 4.09 dBic at 2.9 GHz. Good agreement was also achieved between measurement and simulation results.

For the sustainable production of transportation fuel from renewable resources, the production of biobutanol via ABE (acetone–butanol–ethanol) fermentation was investigated using the acid hydrolysate of short-rotation coppice willow as a raw material. Two-year-old willow bark and woody core biomass were selected as biomass sources for this work. ABE fermentation was accomplished using Clostridium beijerinckii . The overall chemical composition and monosaccharide composition in the woody core and bark were evaluated. According to the overall compositional analysis, the stem biomass contained 70% polysaccharides, which was significantly higher than that of bark, which was 46%. However, the better response of the bark biomass to acid hydrolysis and presence of possible fermentation inhibitors (acetic acid, formic acid, and total phenolics) led to a similar monosaccharide concentration in the stem and bark. Willow bark and the woody core showed similar ABE fermentation patterns with C. beijerinckii . The monosaccharide solutions from both the bark and stem biomass had problems in the transition from the acid-producing pathway to the solvent-producing pathway during ABE fermentation.

In this paper, we designed Interpolation FIR(Finite Impulse Response) filter and 1-bit SDM(Sigma- Delta Modulator) for small digital audio speaker, which has low power consumption and high output characteristics. In order to achieve high linearity and low distortion performance of the systems, we adopt Type I Chevychev FIR filter which has equiripple characteristics in the pass band and proposed high efficient FIR filter structure. SDM is the most efficient modulation technique among the noise shaping techniques. In this paper, we implemented SDM using CIFB(Cascade of Intergrators, Feed-Back) which is generally used in DAC of small digital audio speakers. The proposed SDM structure can achieve high SNR, high-efficiency characteristics and low power consumption in mobile devices. Also considering manufacture of SoC(System on Chip), we performed simulation with Matlab and Verilog HDL to obtain optimal number of operational bits and verified a good experimental results.

Voice activity detection plays an important role for an efficient voice interface between human and mobile devices, since it can be used as a trigger to activate an automatic speech recognition module of a mobile device. If the input speech signal can be recognized as a predefined magic word coming from a legitimate user, it can be utilized as a trigger. In this paper, we propose a voice trigger system using a keyword-dependent speaker recognition technique. The voice trigger must be able to perform keyword recognition, as well as speaker recognition, without using computationally demanding speech recognizers to properly trigger a mobile device with low computational power consumption. We propose a template based method and a hidden Markov model (HMM) based method for the voice trigger to solve this problem. The experiments using a Korean word corpus show that the template based method performed 4.1 times faster than the HMM based method. However, the HMM based method reduced the recognition error by 27.8% relatively compared to the template based method. The proposed methods are complementary and can be used selectively depending on the device of interest.

In general, the reproduced colors on a TV screen are not exactly the same as the colors of the original images transmitted from a TV station because color signals are distorted due to internal and external factors of a TV system. In this paper, we have developed a real time color correction circuit using a colorimetric color processing technique, which is based on 2-dimensional chromaticity region separation. In addition, a preference color processing technique is also used. This circuit has been modeled in VHDL, implemented in an 130,000 gate chip, and applied to TV systems.

A benchmark program provides objective and quantitative experimental data that is used in HW architecture design and as performance criteria. For that reason, a benchmark point must be fairly calculated to make a right decision. It is difficult to benchmark with fairness in embedded systems such as smartphones since there are many HW and SW development environments. For example, iOS adopts ObjectC language and Android supports Java and C/C++ to develop applications. Therefore, it is impossible to apply the same native workload without modification to both iOS and Android platforms. Web-based benchmark programs can solve the problem of fairness. If a platform supports a browsing system, then we can run the same web benchmark program on that platform. In this paper, we construct a web-based benchmark program with JavaScript and HTML5 to evaluate an entire HW platform. The JavaScript workload has three components and the HTML5 workload has two components. Experiment shows that similar runtime characteristics are maintained between native and web workloads. Moreover, we use a compared ratio method to relieve result distortion that comes from unexpected system overheads. Finally, we run our benchmark program on the iOS and many Android platforms.

MPEG-4 Part-10 AVC/H.264 (H.264/AVC) is the newest video coding standard developed and finalized in March 2003 by the Joint Video Team (JVT) of ISO/IEC (MPEG) and ITU-T (VCEG). It includes many powerful features such as multiple reference pictures, variable block-size motion compensation, quarter-pel accuracy motion compensation, and so on. As a result, it achieves high coding performance but at the expense of huge computational complexity. To reduce the complexity while keeping the same coding performance, we propose a low complexity subpel motion estimation method using two content-aware decision criteria. Based on the criteria, four different levels of subpel motion estimation are proposed to achieve low complexity subpel motion estimation. Simulation results show that the proposed method reduces total encoding time by 55.53% on average and subpel motion estimation time by 82.2% on average.

To achieve high video quality for real-time video streaming over the mobile WiMAX network, it is necessary to adaptively adjust the target bit rate of the video encoder based on verified network status. Since it is difficult to verify network congestion using only PHY-layer parameters, this paper proposes an algorithm for verifying network status by using a MAC-layer parameter implying PHY-layer information and then correspondingly adjusting the target bit rate. The results show that the proposed algorithm achieves a video quality 0.7 to 6.3 dB higher than that achieved with fixed target bit rates over the mobile WiMAX network.

This paper presents a decision directed blind adaptive algorithm for carrier phase offset recovery of 8-VSB. The algorithm achieves phase recovery by minimizing the quadrature leakage into the in-phase component and removes undesirable local minima, which occur in most blind algorithms, by configuring the reliable leakage estimation region.

In general, added noise in clean signal reduces intelligibility and degrades the performance of speech processing algorithms used for the applications such as speech compression and recognition In this paper, a new voice clarity enhancing method using a dissonant frequency filtering (DFF) (especially C # and F # in each octave band when reference frequency is C) combined with noise suppression (NS) is proposed The proposed method targets for speakers whose intelligibility became worse than normal under both noisy and noiseless environments. The test results indicate that the proposed method provides a significant audible improvement for speakers whose intelligibility is impaired and especially for the speech contaminated by the colored noise Therefore when the filter is employed as a pre-filter for enhancing the clarity of husky voice where several types of noises are also exploited, the output speech quality and clarity can be greatly enhanced.

A modulation and coding scheme selection method, proposed by Kim and et al. (3GPP2 TSG-C, C50-20011203-014, 2001), is used for an adaptive modulation and coding (AMC) scheme in cdma2000 1xEV-DV. The proposed method, so-called modulation order product code rate (MPR), provides a good criteria for selection of modulation and code rate among various AMC levels, with more than 127 levels for accurate channel adaptation and maximal system throughput. We introduce the properties of MPR and applications in cdma2000 1xEV DV.

In this paper, we present the development platform (DP) of a user equipment (UE) baseband modem in compliance with 3GPP Release 99 FDD specification. The configuration of the development platform and a detailed explanation of test items are described. The functionality and performance of the UE modem and protocol stacks (layer 1 and layer 2/3) are confirmed by HW/SW co-verification using Seamless CVE and call tests using the Anritsu MD8480A base station simulator. Currently, the UMTS UE modem chip based on development platform is implemented in 0.18 /spl mu/m CMOS technology and tests on the chip are in progress.

This paper proposes a high-speed FFT processor for orthogonal frequency-division multiplexing (OFDM) systems. The proposed architecture uses a single-memory for a small hardware size and uses a radix-4 algorithm for high speed. Its memory is partitioned into four banks for high-speed computation. It uses an in-place memory strategy that stores butterfly outputs in the same memory location used by butterfly inputs. The architecture has been modeled by VHDL and logic synthesis has been performed using the Samsung/sup /spl trade// 0.5/spl mu/m SOG cell library (KG80). The implemented FFT processor consists of 98,326 gates excluding RAM. The processor can operate at 42MHz and calculate a 256-point complex FFT in 6/spl mu/s.

In broadband communication, the design of the switching structure of the TU-11/TU-12 signals, the low level signals, is a necessary element for the ADM (add-drop multiplex) and DCS (digital cross-connection system) which compose the optical transmission equipment. This paper presents the multiplexing process of the low level signals that compose the STM-1 frame. In addition, it shows the design of the switching structure of the TU-11 and TU-12 signals used as the input signals of the transmission equipment, and suggests the method of designing the non-blocking switching structure which effectively reduces the existing memory area for the multi-port switching structure design. Actually, this memory saving switching structure has shown effective performance in the 4-port STM-1 frame, especially in the transmission equipment system over STM-4 (622.08 Mbps), and will be used widely in the system configuration that transmits data at 1 Gbps or faster.

A simple and efficient stopping criterion for iterative turbo decoding is proposed, focusing on not only reducing the average number of iterations but also minimising performance degradation due to early stopping. A measure and two decision thresholds are introduced to enhance performance and simplify the stopping criterion. Simulation results show that the proposed method provides performance very close to that of a decoder with optimum stopping criterion and reduces average number of decoding iterations.

In this paper, we propose a novel bandwidth-efficient handoff scheme for proxy mobile IPv6 networks. Mobile nodes (MNs) are classified as either slow or fast; first, though, to implement a bandwidth-efficient handoff scheme, an MN should be registered in a microcell. The microcell is overlapped to handle an overflow session request, which is nested; in a macrocell, an overflow session request makes a request to return from the boundary of the new microcell. If idle session traffic is in a cell, it is requested by the target microcell. If the total systemic traffic load is not very large, the proposed scheme provides the best bandwidth efficiency and a more favorable quality of service (QoS) for an MN without the incurrence of a large systemic processing cost.