Compression techniques for Chinese text

With the growth of digital libraries and the internet, large volumes of text are available in electronic form. The majority of this text is English but other languages are increasingly well represented, including large-alphabet languages such as Chinese. It is thus attractive to compress text written in the large alphabet languages, but the general-purpose compression utilities are not particularly effective for this application. In this paper we survey proposals for compressing Chinese text, then examine in detail the application to Chinese text of the partial predictive matching compression technique (PPM). We propose several refinements to PPM to make it more effective for Chinese text, and, on our publicly-available test corpus of around 50 Mb of Chinese text documents, show that these refinements can significantly improve compression performance while using only a limited volume of memory. © 1998 John Wiley & Sons, Ltd.     

Getting Specific

The Art and Architecture Partnership, known for commissioning public works such as Softroom's Belvedere and James Turrell's Skyspace, has recently awarded its first architectural residency at Kielder to sixteen*(makers). Here, Phil Ayres introduces initial questions for an evolutionary design process that the practice has begun to explore and will execute as a series of interventions on the landscape. Copyright © 2005 John Wiley & Sons, Ltd.     

Improved dielectric performance of polypropylene/multiwalled carbon nanotube nanocomposites by solid‐phase orientation

By means of a die‐drawing technique in the rubbery state, the effect of the orientation of the microstructure on the dielectric properties of polypropylene (PP)/multiwalled carbon nanotube (MWCNT) nanocomposites was examined in this study. The viscoelastic behavior of the PP/MWCNT nanocomposites with MWCNT weight loadings ranging from 0.25 to 5 wt % and the dielectric performance of the stretched PP/MWCNT nanocomposites at different drawing speeds and drawing ratios were studied to obtain insight into the influences of the dispersion and orientation state of the MWCNTs and matrix molecular chains. A viscosity decrease (ca. 30%) of the PP/MWCNT‐0.25 wt % (weight loading) melt was obviously due to the free volume effect. Differential scanning calorimetry (DSC) and wide‐angle X‐ray diffraction were adopted to detect the orientation structure and the variation of crystal morphology of the PP/MWCNTs. Melting plateau regions, which indicated the mixed crystallization morphology for the stretched samples, were found in the DSC patterns instead of a single‐peak for the unstretched samples. We found that the uniaxial stretching process broke the conductive MWCNT networks and consequently increased the orientation of MWCNTs and molecular chains along the tensile force direction; this led to an improvement in the dielectric performance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42893.     

Antioxidant Activity of Sesamin in Canola Oil

The present study presents the antioxidant activity of sesamin in canola oil compared with that of butylated hydroxytoluene (BHT) by monitoring the oxygen consumption and the decrease in linoleic acid and α-linolenic acid. The oxidation of canola oil was conducted at 35, 60, 90, 120 and 180 °C with addition of 50–400 ppm sesamin. Results from the oxygen consumption test showed that sesamin dose-dependently inhibited the oxidation of canola oil at concentrations of 50–200 ppm at temperatures of 60–180 °C, however, sesamin lost its antioxidant activity at a low temperature of 35 °C. The fatty acid analysis also demonstrated that sesamin at 50, 100 and 200 ppm dose-dependently prevented the oxidation of linoleic acid and α-linolenic acid in canola oil. Both the oxygen consumption and the fatty acid analysis demonstrated sesamin was less effective than BHT as an antioxidant at temperatures of 60–180 °C. It was therefore concluded that sesamin could prevent the lipid oxidation of frying fats and oil, however, its antioxidant activity was not as potent as that of BHT.     

Synthesis and Dispersion of Dendrimer-Encapsulated Pt Nanoparticles on γ-Al2O3 for the Reduction of NO x by Methane

Dendrimer encapsulated Pt nanoparticles were prepared by using hydroxyl terminated generation four (G4OH) PAMAM dendrimers (DEN) as the templating agents. The encapsulated Pt nanoparticles were dispersed on γ-Al₂O₃ at room temperature by impregnation. Pt/Al₂O₃ (DEN) catalysts were then subjected to thermal treatments in oxidizing and reducing atmospheres at different temperatures. These catalysts were characterized by Transmission Electron microscopy (TEM) and In situ Fourier-Transform Infrared (FTIR) spectroscopy. The TEM analysis of the as synthesized catalysts revealed that the Pt nanoparticles were found to be 2–4 nm in size. It is observed that the Pt particle size in 0.5% Pt/Al₂O₃ (DEN) catalyst increased upon thermal decomposition of the dendrimer. The in situ FTIR results suggested that the presence of oxygen and the Pt nanoparticles in the Pt-dendrimer nanocomposite accelerate the dendrimer decomposition at low temperatures. All the catalysts were tested for the reduction of NO _x with CH₄ in the temperature range of 250–500 °C. NO _x reduction efficiency of Pt/Al₂O₃ (DEN) catalysts were compared with the Pt/Al₂O₃ (CON; conventional) catalyst. The conversion of NO _x was started from the low temperatures over Pt/Al₂O₃ (DEN) catalysts. The high selectivity of NO _x to N₂ of 74% was obtained over 0.5% Pt/Al₂O₃ (DEN) catalyst at low temperatures around 350 °C.     

展望2004

肉食与家畜委员会 (MLC)在2 0 0 4年 1月 2 8日主持召开了一个以“展望 2 0 0 4的转变与机遇”为议题的会议 ,会议的目的是探讨英国未来几年畜牧业及其相关行业的最新发展趋势 ,来自畜牧业、肉食业以及相关领域的 1 5 0多位代表参加了会议。MLC主席彼得·巴尔先生致开幕辞拉开了会议的帷幕 ,巴尔先生说 ,鲜肉消费在经过近 1 2a的发展达到了最高点 ,这个领域是轻松愉快而且大有挖掘潜力的 ;在此他也宣布了有关新近肉食工业讨论会 (RMIF)成立的通告。该讨论会是一个以促进行业最佳业绩为己任的智囊机构。目前DEFRA已向该智囊机构捐赠了 …     

The pervasiveness of evolution in GRUMPS software

This paper describes the evolution of the design and implementation of a distributed run‐time system that itself is designed to support the evolution of the topology and implementation of an executing, distributed system. The three different versions of the run‐time architecture that have been designed and implemented are presented, together with how each architecture addresses the problems of topological and functional evolution. In addition, the reasons for the rapid evolution of the design and implementation of the architecture are also described. From the lessons learned in both evolving the design of the architecture and in trying to provide a run‐time system that can support run‐time evolution, this paper discusses two generally applicable observations: evolution happens all the time, and it is not possible to anticipate how systems will evolve as designs; and large, run‐time systems do not follow a predictable path. In addition to this, rapid prototyping has proved to be extremely useful in the production of the three architectures; this kind of prototyping has been made much easier by designing the core set of Java abstractions in terms of interfaces; and building an architecture that allows as many decisions as possible to be made at run‐time which has produced a support system that is more responsive to the user as well as the distributed environment in which it is executing. Copyright © 2003 John Wiley & Sons, Ltd.     

A fast pipelined VLSI adder for fast trigger decisions at the Superconducting Super Collider

We present a four 12-bit binary number adder proposed for use in the computation of the pipelined energy sums of data from the detectors at the Superconducting Super Collider (SSC). It was fabricated using a 1.2 μm N-well CMOS process. It comprises three 12-bit adders organized as a two-stage pipeline. To compute the final carry of each of the 12-bit adders, we used the Carry-Select technique applied to their 4-bit adder subcells. The 4-bit adders used the Carry-Lookahead method to compute their carries. In order to reduce the circuit area and to simplify the structure of this application specific integrated circuit (ASIC) we employed a Multiple-Output Domino Logic design style. The first stage of the pipeline (two adders) performs two 12-bit additions in parallel while the second stage (one adder) finishes up the previously started computation. The pipeline is driven using a two-phase clocking strategy by processing a single-phase external clock. We achieved an worst case throughput of 18 ns. In the best case the throughput was 16.5 ns. We included a built-in facility for testing the first stage of the pipeline. The area of the circuit is 1425×5510 μm², it has 76 pads, and it is packed in a 132 pin grid array (PGA). The transistor count is 6639. The dissipated power at a 18-ns clock period was ≈ 0.75 W. The circuit has been fabricated through the MOSIS service. We found an yield of ≈ 80% for a lot of 50 chips.     

A simple network model simulates hippocampal place fields: II. Computing goal-directed trajectories and memory fields.

Place cells have been described as the computational elements of a neuronal cognitive mapping system that encodes and stores relationships among spatial stimuli (J. O'Keefe and L. Nadel, 1978). Furthermore, place cells seem to encode remembered locations because neural activity is maintained when the visual stimuli that influence place field location are vastly degraded, such as when cues are removed or the lights are turned off (O'Keefe and A. Speakman, 1987; G. J. Quirk et al, 1990). A feed-forward network model that mapped visual input onto a representation of location simulated some basic properties of hippocampal place fields, including resistance to disruption after partial cue memory (M. L. Shapiro and P. A. Hetherington, 1993). However, the simulated place fields required visual input for their activation. It is reported that a network that incorporates feedback (1) computed correct trajectories toward simulated goals and (2) simulated place fields that persist in the absence of visual input. The simulation suggests that feedback properties can provide a computational account of O'Keefe and Speakman's data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)