14819907
Precise RSSI with High Process Variation Tolerance
A receiving signal strength indicator (RSSI) built with transconductance amplifiers is presented. The RSSI achieves high tolerance to process variations by utilizing the unique nature of branch currents in a transconductance amplifier. These branch currents are used to implement a current-mode rectifier and amplitude clipping circuit that are tolerant of process variations. An on-chip offset control loop permits the entire RSSI to be realized with only one external component. In 0.18 mum CMOS with a 1.8V supply, the RSSI draws 2.5mA and provides 80dB of offset suppression and more than 70dB of log-linear range with less than +/-2dB error due to process variation.
14945726
Zero-IF VGA with novel offset cancellation
Reliable offset control is a vital feature of a zero-IF variable gain amplifier (VGA). Many traditional methods sacrifice speed (settling time) to achieve offset control by realizing a high pass feature in the signal path. This paper introduces a novel VGA architecture that is capable of controlling offset for all gain settings with a single offline calibration cycle. The VGA realizes very fast gain/startup settling time with only a slight increase in power and area requirements by eliminating the need for a high pass filter. The VGA circuit draws 3mA and has a gain range of 0~42dB with 1dB steps. It has a 10MHz bandwidth at 42dB, has a gain settling time of 140nsec, and controls output offset within 2.2mV
19017390
Amperometric Readout and Electrode Array Chip for Bioelectrochemical Sensors
As nanostructured bioelectronic interfaces continue to evolve for sensor applications, new readout circuits are needed to harness their capabilities. This paper presents a single-chip amperometric readout circuit and electrode array system suitable for bioelectrochemical measurements. The chip features a CMOS potentiostat with high resolution, range-programmable current readout and electrochemical cell potential drive circuitry, which can perform on-chip chronoamperometry and cyclic voltammetry assays. Through post-CMOS fabrication, the surface of the chip is prepared with an array of electrodes suitable for formation of bioelectronic interfaces and on-chip bioelectrochemical measurements. The 3times3mm2 chip nominally hosts a 4times4 working electrode array and supports amperometric outputs ranging from 10pA to 10muA with sub-pA resolution.
1742512
On Construction of a Large File System Using PVFS for Grid
Grid is the largest advance of network after Internet since the Grid System provides a specialty that can be used popularly and effectively. However, it is a challenge to the consistency and community of use on the data storages space of a Grid System. Therefore, the problem of application for the Computational Grid and Data Grid is more important. It can set up a usability, expandability, high operation capability, and large memory space in Grid with the Cluster system and parallel technique in order to solve the problem. In this paper, we provided a Grid with high operation capability and higher memories to solve the problem. As to the Grid setting, we take use of the Cluster computing to increase the operation effect for computing, and a PVFS2 with more storages effect for data. It can supply a quite correct platform for Grid user whether for large data access or huge operation.
16561888
Learning to predict train wheel failures
This paper describes a successful but challenging application of data mining in the railway industry. The objective is to optimize maintenance and operation of trains through prognostics of wheel failures. In addition to reducing maintenance costs, the proposed technology will help improve railway safety and augment throughput. Building on established techniques from data mining and machine learning, we present a methodology to learn models to predict train wheel failures from readily available operational and maintenance data. This methodology addresses various data mining tasks such as automatic labeling, feature extraction, model building, model fusion, and evaluation. After a detailed description of the methodology, we report results from large-scale experiments. These results clearly show the great potential of this innovative application of data mining in the railway industry.
15657957
Automatic Summarization of Chinese and English
As a result of the rapid growth in Internet access, significantly more information has become available online in real time. However, there is not sufficient time for users to read large volumes of information and make decisions accordingly. The problem of information-overloading can be resolved through the application of automatic summarization. Many summarization systems for documents in different languages have been implemented. However, the performance of summarization system on documents in different languages has not yet been investigated. In this paper, we compare the result of fractal summarization technique on parallel documents in Chinese and English. The grammatical and lexical differences between Chinese and English have significant effect on the summarization processes. Their impact on the performances of the summarization for the Chinese and English parallel documents is compared.
5690098
Gamut clipping in color image processing
Multiple color coordinate systems are usually involved in color image applications or systems. Forward and backward transformations are used to switch between color coordinate systems. The out of gamut problem emerges when the color coordinate systems' gamut is different. Conventional approaches, including clipping R, G, B values and clipping luminance value are not ideal as they both produce severe error in the luminance component of the resulting color or reduce the contrast of the resulting image. We propose to clip the saturation value when a vector is out of the gamut of the LHS or YIQ space using the saturation processing equations. We have conducted experiments to compare three different clipping approaches. The experimental results show that the saturation clipping approach outperforms the other two approaches, in the sense that it can keep the luminance value unchanged. In addition, the contrast of the image produced by saturation clipping is much better than those produced by other clipping approaches.
18362603
Apply cluster and grid computing on parallel 3D rendering
A cluster is a collection of independent and cheap machines, used together as a supercomputer to provide a solution. In this paper, a PC cluster consisting of one master node and nine disk-less slave nodes (10 processors), is proposed and built for parallel rendering purposes. The system architecture and benchmark performances of this cluster are also presented. Internet computing and grid technologies promise to change the way we tackle complex problems. They will enable large-scale aggregation and sharing of computational, data and other resources across institutional boundaries. Harnessing these new technologies effectively will transform scientific disciplines ranging from high-energy physics to the life sciences. Also, in this paper, we construct two heterogeneous PC clusters for parallel rendering purpose and install Linux Red Hat 9 on each PC cluster. Then, these clusters are set to the different subnet. Therefore, we use the grid middleware lambdaobus ToolKit, to connect these two clusters to form a grid computing environment on multiple Linux PC clusters. We also install the SUN Grid Engine, to manage and monitor incoming or outgoing computing jobs and schedule the job to achieve high performance computing and high CPU utilization. The system architecture and benchmark performances of this cluster are also presented