High Speed

Key issues related to the modeling of ultra-high speed transmission are discussed in this paper. These topics include components modeling, link modeling and BER estimation. Different solutions for the transport of 100 Gb/s over a single wavelength including technologies such as coherent detection, polarization multiplexing, optical OFDM, and digital signal processing are reviewed and compared with means of numerical simulations.

To alleviate the feed fluctuation and to maintain a smooth feed in conventional five-axis machining, an optimal feed interpolation algorithm (look-ahead) is proposed. However, the problem arises where the segment usually cannot be interpolated exactly in an integer period because of the nonzero joint feed at the junction. To overcome this problem, and to achieve faster machining speed and higher quality parts, this paper presents an optimal feed interpolation algorithm for high-speed, five-axis machining having the function of “look-ahead”, i.e., variable-period linear interpolation algorithm. In real applications, the proposed algorithm results in: (1) constant speed; (2) high machining accuracy. Moreover, in this paper, an efficient method for acceleration and deceleration control is presented to achieve the highest-quality feed profiles and to shorten machining times. The precision and speed of machining is improved greatly. Experimental results verify the effectiveness of the proposed method.

Passive means of vibration attenuation have been employed successfully and efficiently in machining systems such as turning and milling. Traditional approach to controlling vibration in a milling system is to develop control mechanisms for cutting tools or machine spindles. However, due to the nature of milling operations where the cutting tools rotate at high speed, the passive vibration control methods

With the advent of the IEEE 802.11 wireless networks that provide high speed connectivity, demand for supporting multiple real-time traffic appli-cations over wireless LANs has been increasing. A natural question is how to provide fair resource allocation to real-time traffic in wireless LANs. Wireless networks are subject to unpredictable location-dependent error bursts, which is different from wired networks. We propose a fair real-time scheduling model whose goal is to minimize the maximum loss rate among all the flows and additionally to maximize the overall throughput. We de-velop algorithms for this scheduling model that takes the wireless channel error characteristics into consideration. I.

This paper proposes a new H∞ yaw-moment control scheme using brake torque for improving vehicle performance and stability especially in high speed driving. Its characteristics is that only one brake is used for control depending on the vehicle state. Steering angles are modeled as a disturbance input to the system and the controller minimizes the difference between the performance of

In this paper, a methodology for the development of fault-tolerant adders based on the radix 2 signed digit (SD) representation is presented. The use of a number representation characterized by a carry propagation confined to neighbor digits implies interesting advantages in terms of error detection, fault localization, and repair. Errors caused by faults belonging to a considered stuck-at fault set can be detected by a parity-based technique. In fact, a carry-free adder preserving the parity of the augends can be implemented allowing fault detection by using a parity checker. Regarding fault localization, the "carry-free" property of the adder ensures the confinement of the error due to a permanent fault to only few digits. The detection of the faulty digit has been obtained by using a recomputation with shifted operands method. Finally, after the fault localization, graceful degradation of the system intended as the reduction of the performances versus a correct output computation can be obtained by using two different procedures. The first one allows obtaining the correct output by recomputing the result performing two different shift operations and using the intersection of the obtained results to recover the correct output, while the second one is based on a reduced dynamic range approach, which allows us to obtain the result in only one step, but with fewer output digits.

This paper proposes a software based parallel CRC (Cyclic Redundancy Check) algorithm called 'N-byte RCC (Repetition of Computation and Combination)''. This algorithm is the iterative process of message computation by the 'slicing-by-4' and combination through the 'zero block lookup tables'. This algorithm can parallelize the CRC calculation with any number of processors. In order to verify the performance of our algorithm, we employ two different communication architectures; the single bus architecture and the 1-star topology NoC (Network on Chip) architecture. With respect to those architectures, we explore our parallel algorithm by using TLM (Transaction Level Model). From the simulation results, we present that the proposed parallel CRC algorithm with BUS and NoC architectures reduces the processing time by 28 percent and 38 percent, respectively, compared to the 'slicing-by-8' which is the fastest algorithms among other software based algorithms. Furthermore, the 1-star NoC architecture of the parallel CRC shows higher performance than the single bus architecture regardless of the number of processors.

Abstract Next-generation wireless networks will integrate multiple wireless access technologies to provide seamless mobility to mobile users with high-speed wireless connectivity. This will give rise to a heterogeneous wireless access environment where ...

We present a model of energy consumption in IP networks. Using this model, we identify energy ldquohotspotsrdquo and estimate how energy consumption will grow with increasing network capacity. Todaypsilas Internet uses less than 1% of the available electricity supply. However, network energy consumption could grow substantially as access rates increase.

Powders and granulated solids are widely used in industrial bulk solids storage, handling, and transportation systems. Such bulk materials handling operations frequently involve a falling stream of material. During such a process, the surrounding air is induced to flow with the falling particle stream, forming a particle-driven plume. Herein, experimental research results are reported on this fundamental problem, focusing in

Microarrays containing 1046 human cDNAs of unknown sequence were printed on glass with high-speed robotics. These 1.0-cm2 DNA "chips" were used to quantitatively monitor differential expression of the cognate human genes using a highly sensitive two-color hybridization assay. Array elements that displayed differential expression patterns under given experimental conditions were characterized by sequencing. The identification of known and novel heat shock and phorbol ester-regulated genes in human T cells demonstrates the sensitivity of the assay. Parallel gene analysis with microarrays provides a rapid and efficient method for large-scale human gene discovery.

A detailed analytical and experimental investigation is presented to understand the dynamic fracture behavior of functionally graded materials (FGMs) under mode I and mixed mode loading conditions. Crack-tip stress, strain and displacement fields for a mixed mode crack propagating at an angle from the direction of property gradation were obtained through an asymptotic analysis coupled with a displacement potential approach. This was followed by a comprehensive series of experiments to gain further insight into the behavior of propagating cracks in FGMs. Dynamic photoelasticity coupled with high-speed photography was used to obtain crack tip velocities and dynamic stress fields around the propagating cracks. Birefringent coatings were used to conduct the photoelastic study due to the opaqueness of the FGMs. Dynamic fracture experiments were performed using different specimen geometries to develop a dynamic constitutive fracture relationship between the mode I dynamic stress intensity factor (K ID ) and crack-tip velocity ( ${\mathop a\limits^ \cdot }$ ) for FGMs with the crack moving in the direction of increasing fracture toughness. A similar ${\mathop a\limits^ \cdot }$ -K ID relation was also obtained for matrix material (polyester) for comparison purposes. The results obtained show that crack propagation velocities in FGMs were about 80% higher than the polyester matrix. Crack arrest toughness was found to be about 10% lower than the value of local fracture toughness in FGMs.

Multimodal interaction is becoming common in many kinds of devices, particularly mobile phones. If care is not taken in design and implementation, there may be latencies in the timing of feedback in the different modalities may have unintended effects on users. This paper introduces an easy to implement multimodal latency measurement tool for touchscreen interaction. It uses off-the-shelf components and