Detection of microorganisms and toxins with evanescent wave fiber-optic biosensors

Conventional procedures to detect microorganisms and toxins in food, water, and human specimens can take hours or days to perform and may provide inconclusive identification. The complex nature of many sample matrices as well as the presence of particulate matter in samples often severely reduces the sensitivity and specificity of conventional bacterial detection systems, especially those that rely on immunological reactions for capture or detection. Evanescent wave fiber-optic biosensors can identify such target analytes in minutes directly from complex matrix samples using robust antibody-based assays, significantly improving the detection sensitivity, selectivity, and speed. In addition, live microbial targets can be recovered from fiber-optic waveguides to determine microorganism viability, confirm identification, and preserve as evidence.     

Single-Chip Eye Tracker Using Smart CMOS Image Sensor Pixels

The eye tracker is a system that detects the point where the user gazes on. The conventional eye tracker using a Charge-Coupled Device (CCD) camera needs many peripherals and software computation causing high cost, computation time and power consumption. This paper proposes a single-chip eye tracker using smart CMOS Image Sensor (CIS) pixels. The proposed eye tracker does not require additional peripherals and operates at higher speed than the conventional approach. The prototype chip was designed and fabricated for a 32 × 32 smart CIS pixels array with a 0.35-μ m CMOS process. The test results show ± 1 pixel error at the rate of 125 frame-per-second. The power consumption is 260 mW with 3.3 V supply voltage and the silicon area is 3.8 mm²     

Home photo content modeling for personalized event-based retrieval

Rapid advances in sensor, storage, processor, and communication technologies let consumers store large digital photo collections. Consumers need effective tools to organize and access photos in a semantically meaningful way. We address the semantic gap between feature-based indexes computed automatically and human query and retrieval preferences.     

Adaptive Kernel Function of SVM for Improving Speech/Music Classification of 3GPP2 SMV

Because a wide variety of multimedia services are provided through personal wireless communication devices, the demand for efficient bandwidth utilization becomes stronger. This demand naturally results in the introduction of the variable bitrate speech coding concept. One exemplary work is the selectable mode vocoder (SMV) that supports speech/music classification. However, because it has severe limitations in its classification performance, a couple of works to improve speech/music classification by introducing support vector machines (SVMs) have been proposed. While these approaches significantly improved classification accuracy, they did not consider correlations commonly found in speech and music frames. In this paper, we propose a novel and orthogonal approach to improve the speech/music classification of SMV codec by adaptively tuning SVMs based on interframe correlations. According to the experimental results, the proposed algorithm yields improved results in classifying speech and music within the SMV framework.     

Design and implementation of multicasting for multi-channel multi-interface wireless mesh networks

Multicasting is a useful communication method in wireless mesh networks (WMNs). Many applications in WMNs require efficient and reliable multicast communications, i.e., high delivery ratio with low overhead among a group of recipients. In spite of its significance, little work has been done on providing such multicast service in multi-channel WMNs. Traditional multicast protocols for wireless and multi-hop networks tend to assume that all nodes, each of which is equipped with a single interface, collaborate on the same channel. This single-channel assumption is not always true, as WMNs often provide nodes with multiple interfaces to enhance performance. In multi-channel and multi-interface (MCMI) WMNs, the same multicast data must be sent multiple times by a sender node if its neighboring nodes operate on different channels. In this paper, we try to tackle the challenging issue of how to design a multicast protocol more suitable for MCMI WMNs. Our multicast protocol builds multicast paths while inviting multicast members, and tries to allocate the same channel to neighboring members in a bottom-up manner. By unifying fixed channels of one-hop multicast neighbors, the proposed algorithm can improve the performance such as reducing multicast data transmission overhead and delay, while managing a successful delivery ratio. In order to prove such expectation on the performance, we have implemented and evaluated the proposed solution on the real testbed having the maximum 24 nodes, each of which is equipped with two IEEE 802.11a Atheros WLAN cards.     

Image watermarking using Hadamard transforms

A novel method based on the multi-resolution transform and complex Hadamard transform to embed watermarks in grey scale digital images is proposed. The results show that the presented scheme is robust to JPEG compression, image resizing cropping, dithering distortion and successive watermarking effects     

Two-phase boosted voltage generator for low-voltage DRAMs

A two-phase boosted voltage (V/sub PP/) generator circuit was proposed for use in gigabit DRAMs. It reduced the maximum gate-oxide voltage of pass transistor and the lower limit of supply voltage to V/sub PP/ and V/sub TN/, respectively, while those for the conventional charge-pump circuit are V/sub PP/+V/sub DD/ and 1.5 V/sub TN/ respectively. Also, the pumping current was increased in the new circuit. The newly proposed two-phase V/sub PP/ charge-pump circuit worked successfully at V/sub DD/ down to 0.8 V by eliminating the threshold voltage loss of the control pulse generator and was tested successfully in a 0.16-/spl mu/m test chip using triple-well CMOS technology.     

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.