S/W Based Frame‐Level Synchronization for Irregular Screen Processing System

A multi‐screen environment provides a new opportunity for digital signage applications, where various irregularly shaped screens are employed as an effective means for advertisements and information. A formation method applicable to numerous irregularly shaped screens is proposed to provide a new perspective on digital signage applications. The crucial part of the proposed method comes from the geometric sensing of each screen and the formation of a virtual screen where geometrically aligned content extraction and encoding are employed for content transmission to each screen. In addition, a software‐based synchronization method for the proposed system is proposed to address the frame‐level synchronization between screens. The experimental results of the proposed method show an improved performance of the frame‐level synchronization, where the inconsistency between frames is not identified.     

Text-line extraction in handwritten Chinese documents based on an energy minimization framework

Text-line extraction in unconstrained handwritten documents remains a challenging problem due to nonuniform character scale, spatially varying text orientation, and the interference between text lines. In order to address these problems, we propose a new cost function that considers the interactions between text lines and the curvilinearity of each text line. Precisely, we achieve this goal by introducing normalized measures for them, which are based on an estimated line spacing. We also present an optimization method that exploits the properties of our cost function. Experimental results on a database consisting of 853 handwritten Chinese document images have shown that our method achieves a detection rate of 99.52% and an error rate of 0.32%, which outperforms conventional methods.     

Optimization of Fiber Bragg Gratings Using a Hybrid Optimization Algorithm

A new hybrid optimization algorithm is proposed for the design of a fiber Bragg grating (FBG) with complex characteristics. The hybrid algorithm is a two-tier search that employs a global optimization algorithm (i.e., the staged continuous tabu search (SCTS) algorithm) and a local optimization method (i.e., the quasi-Newton method). First, the SCTS global optimization algorithm is used to find a "promising" FBG structure that has a spectral response as close as possible to the targeted spectral response. Then, a local optimization method, namely, the quasi- Newton method, is applied to further optimize the promising FBG structure obtained from the SCTS algorithm to arrive at a targeted spectral response. To demonstrate the effectiveness of the method, the design and fabrication of an optical bandpass filter are presented.     

A Multi‐Functional Highly Efficient Upconversion Luminescent Film with an Array of Dielectric Microbeads Decorated with Metal Nanoparticles

Upconversion nanoparticles (UCNPs) have been integrated with photonic platforms to overcome the intrinsically low quantum efficiency limit of upconversion luminescence (UCL). However, platforms based on thin films lack transferability and flexibility, which hinders their broader and more practical application. A plasmonic structure is developed that works as a multi‐functional platform for flexible, transparent, and washable near‐infrared (NIR)‐to‐visible UCL films with ultra‐strong UCL intensity. The platform consists of dielectric microbeads decorated with plasmonic metal nanoparticles on an insulator/metal substrate. Distinct improvements in NIR confinement, visible light extraction, and boosted plasmonic effects for upconversion are observed. With weak NIR excitation, the UCL intensity is higher by three orders of magnitude relative to the reference platform. When the microbeads are organized in a square lattice array, the functionality of the platform can be expanded to wearable and washable UCL films. The platform can be transferred to transparent, flexible, and foldable films and still emit strong UCL with a wide viewing angle.     

A new method to suppress harmonics using /spl lambda//4 bias line combined by defected ground structure in power amplifiers

A new /spl lambda//4 bias line combined by a dumb-bell shaped defected ground structure (DGS) is proposed to suppress harmonics in power amplifiers. The proposed DGS bias line maintains the required high impedance even after DGS is inserted, while the width and length of the /spl lambda//4 bias line are broader and shorter than those of conventional bias lines. When the DGS bias line is used in power amplifiers, the third harmonic components as well as the second harmonic are reduced, because of the increased slow-wave effect over wide harmonic band. It is shown that the reduction of the third harmonic component, the improvement of 1 dB compression point, and power added efficiency are 26.5 dB, 0.45 dB, and 9.1%, respectively.     

Rotation-Invariant Texture Classification Using Circular Gabor Wavelets Based Local and Global Features

Rotation-invariant texture classification is one of the most challenging problems in computer vision. This paper presents a new and effective method for rotation-invariant texture classification based on the circular Gabor wavelets. The Gabor representation has been shown to be optimal in the sense of minimizing the joint two-dimensional uncertainty in space and frequency. The circular Gabor filter is completely circularly symmetric. So, the circular Gabor wavelets are constructed to decompose an image into multiple scales （subbands） and are rotation invariant. Two group features can be constructed by the mean and variance of the circular Gabor filtered images, and rotation invariant. The experimental results show that the proposed method has comparatively high correct classification rates.     

An uplink CDMA system architecture with diverse QoS guarantees forheterogeneous traffic

The uplink access control problems for cellular code-division multiple-access (CDMA) systems that service heterogeneous traffic with various types of quality-of-service (QoS) and use multicode CDMA to support variable bit rates are addressed. Considering its distinct QoS requirements, class-I real-time traffic (e.g., voice and video) is differentiated from class-II non-real-time traffic (e.g., data). Connection-oriented transmission is achieved by assigning mobile-oriented code channels for class-I traffic, where each corresponding mobile needs to pass an admission test. Class-II traffic is transmitted in a best-effort manner through a transmission-rate request access scheme which utilizes the bandwidth left unused by class-I traffic. Whenever a mobile has class-II messages to transmit, the mobile requests code channels via a base station-oriented transmission-request code channel, then, according to the base station scheduling, the transmission is scheduled and permitted. Addressed are the admission test for class-I connections, transmission power allocation, and how to maximize the aggregate throughput for class-II traffic. The admission region of voice and video connections and the optimum target signal-to-interference ratio of class-II traffic are derived numerically. The performance of class-II traffic transmissions in terms of average delay is also evaluated and discussed     

Ultra-wideband (from DC to 110 GHz) CPW to CPS transition

A new ultra-wideband, low-loss and small-size coplanar waveguide (CPW) to coplanar strip (CPS) transition which can be used from DC to 110 GHz is presented. The proposed transition connects CPW with CPS by the reformed air-bridge. Two ground planes of CPW are tied at their ends by a line and the centre of the line is connected to the ground strip of CPS by another line. Owing to the symmetry of the proposed structure, the currents of two ground planes of CPW are combined with the same phase and transferred to the ground strip of CPS. With height of 3 μm, the signal line of CPW passes over two connecting lines and is connected to the signal strip of CPS. For the back-to-back transition structure, insertion loss <1 dB and return loss >15 dB are obtained from 0.5 to 110 GHz     

Design of 24 GHz Radar with Subspace‐Based Digital Beam Forming for ACC Stop‐and‐Go System

For an adaptive cruise control (ACC) stop‐and‐go system in automotive applications, three radar sensors are needed because two 24 GHz short range radars are used for object detection in an adjacent lane, and one 77 GHz long‐range radar is used for object detection in the center lane. In this letter, we propose a single sensor‐based 24 GHz radar with a detection capability of up to 150 m and ±30° for an ACC stop‐and‐go system. The developed radar is highly integrated with a high gain patch antenna, four channel receivers with GaAs RF ICs, and back‐end processing board with subspace based digital beam forming algorithm.     

A design of a high-speed and high-efficiency capsule endoscopy system

This paper presents a high-speed and high-efficiency capsule endoscopy system. Both a transmitter and a receiver were optimized for its application through an analysis of the human body channel. ON-OFF keying modulation is utilized to achieve low power consumption of the in-body transmitter. A low drop output regulator is adopted to prevent performance degradation in the event of a voltage drop in the battery. The receiver adopts superheterodyne structure to obtain high sensitivity, considering the link budget from the previous analysis. The receiver and transmitter were fabricated using the CMOS 0.13-μm process. The output power of the transmitter is -1.6 dB·m and its efficiency is 27.7%. The minimum sensitivity of the receiver is -80 dB·m at a bit error ratio (BER) of 3 × 10 (-6). An outer wall loop antenna is adopted for the capsule system to ensure a small size. The integrated system is evaluated using a liquid human phantom and a living pig, resulting in clean captured images.