On Striping Traffic over Multiple IEEE 802.11(b) Wireless Channels

Due to interference, path loss, multipath fading, background noise, and many other factors, wireless communication normally cannot provide a wireless link with both a high data rate and a long transmission range. To address this problem, striping network traffic in parallel over multiple lower-data-rate but longer-transmission-range wireless channels may be used. In this paper, we propose a new striping method and evaluate its performances over multiple IEEE 802.11(b) channels under various conditions. Our extensive simulation results show that this method is quite effective for such an application. S.Y. Wang is an Associate Professor of the Department of Computer Science and Information Engineering at National Chiao Tung University, Taiwan. He received his Master and Ph.D. degree in computer science from Harvard University in 1997 and 1999, respectively. His research interests include wireless networks, Internet technologies, network simulations, and operating systems. He is the author of the NCTUns 2.0 network simulator and emulator, which is being widely used by network and communication researchers. More information about the tool is available at http://NSL.csie.nctu.edu.tw/nctuns.html. C.H. Hwang received his master degree in computer science from NCTU in 2002 and currently is working for a network company. C.L. Chou currently is a third-year Ph.D. student at the Department of Computer Science and Information Engineering, National Chiao TungUniversity (NCTU), Taiwan. He received his master degree in computer science from NCTU in 2002.     

On inversive maximal period polynomials over finite fields

Over finite field GF(q) withq a power of an odd primep, we characterize inversive maximal period polynomials in terms of polynomials of orderq + 1, and then we study some properties of polynomials of orderq + 1.This paper was written while the author was visiting the Institute of Information Processing, Austrian Academy of Sciences, AustriaThe author would like to thank the Institute of Information Processing, Austrian Academy of Sciences, Austria, for its hospitality and for using its facilities     

隧道受震破壞調查分析與修復管理案例

就隧道震後之災損模式進行統計與災損原因研判,並利用數值分析方法研判安全性,就結構加固等改善措施之設計考量作詳細說明;另由於隧道結構物的損壞範圍大,且修復經費受限,必須藉由定期檢测進行長期維護管理,以防範意外發生。於此,利用Vidco-GIS自動化影像地理资訊系統之e化新技術,以動態及靜態影像紀錄隧道災損狀況,同時亦整合建置前期設計、施工圖及定期維護等資料,相關成果以資料庫方式纳入日常維護管理,以有限人力有效率地進行維護管理紀錄並随時掌握現況供作決策之明確參考。     

Chronic effects of glucose on insulin signaling in A-10 vascular smooth muscle cells

To examine the effects of hyperglycemia on insulin signaling in A-10 vascular smooth muscle cells, cells were treated with extracellular D-glucose and effects of insulin were studied on the diacylglycerol-protein kinase C signaling system. A-10 cells specifically bound 125I-insulin, and insulin-like growth factor-I did not displace the label. 125I-insulin binding was unaltered under hyperglycemic conditions. To determine if insulin receptors were coupled to other insulin-regulated processes, diacylglycerol, protein kinase C, and glucose transport were evaluated. Insulin increased cellular diacylglycerol (DAG) levels which were also increased following glucose treatment and not further stimulated by insulin. The uptake of 2-[3H]deoxy-D-glucose (2-DOG) was stimulated by insulin and 12-O-tetradecanoyl phorbol 13-acetate (TPA). Insulin- and TPA-stimulated 2-[3H]DOG uptake was inhibited by a protein kinase inhibitor, staurosporine. Preincubation of cells with 500 nM TPA overnight resulted in the inhibition of insulin- and TPA-stimulated 2-[3H]DOG uptake. Protein kinase C activity was translocated from cytosolic to membrane fractions following insulin treatment. Overnight glucose (25 mM) treatment resulted in a 50% decrease in protein kinase C enzyme activity and > 90% decrease in protein kinase C beta immunoreactive levels. Protein kinase C activity and levels were not affected by osmotic control media containing mannitol. A-10 cells express GLUT4-type glucose transporters. Neither insulin-regulatable glucose transporter (GLUT4) mRNA nor GLUT4 protein levels were diminished by glucose. Significant decreases in insulin- and TPA-stimulated 2-[3H]DOG uptake occurred, however, with glucose. The down-regulation of protein kinase C beta and resultant inhibition of 2-[3H]DOG uptake by chronic glucose suggests a biochemical link between hyperglycemia and DAG-protein kinase C signaling in vascular smooth muscle cells.     

Implementation of a vector quantization codebook design technique based on a competitive learning artificial neural network

We describe an implementation of a vector quantization codebook design algorithm based on the frequencysensitive competitive learning artificial neural network. The implementation, designed for use on high-performance computers, employs both multitasking and vectorization techniques. A C version of the algorithm tested on a CRAY Y-MP8/864 is discussed. We show how the implementation can be used to perform vector quantization, and demonstrate its use in compressing digital video image data. Two images are used, with various size codebooks, to test the performance of the implementation. The results show that the supercomputer techniques employed have significantly decreased the total execution time without affecting vector quantization performance.This work was supported by a Cray University Research Award and by NASA Lewis research grant number NAG3-1164.     

True digestibility of amino acids and protein in pigs with 13C as a label to determine endogenous amino acid excretion

The objective of this study was to determine whether differential labeling of 13C occurs in pigs fed diets with different 13C abundances and, if so, to use 13C as a label to determine true amino acid digestibility. Forty-eight pigs averaging 10.5 kg BW were fed dietary treatments consisting of a corn-corn gluten meal-crystalline amino acid diet (C-CGM) and a wheat-soybean meal diet (W-SBM). The 13C abundance of the amino acid fraction (AAF) of the C-CGM and W-SBM diets averaged delta 13C -14.19 and -26.36/1000, respectively. Three pigs/treatment group were killed when groups averaged 10.5 (initial), 22.9, and 46.6 kg BW, and AAF of organs were analyzed for 13C abundance. Carbon 13 in empty body AAF increased (-18.14, -13.98, and -12.66/1000) with increasing body weight in pigs fed the C-CGM diet and decreased (-18.06, -22.78, and -24.76/1000) in pigs fed the W-SBM diet. Liver, small intestine, and longissimus muscle tissues showed similar trends. Each tissue had dietary treatment effects (P < .001) and dietary treatment x weight group (P < .001) interactions. Ten pigs averaging 55.0 kg BW from each treatment group were assigned to metabolism cages and fed at 0700 and 1900. Six of these pigs from each treatment group were implanted with T-cannulas in the ileum and given a 17-d recovery period. At 1900 on d 0 of the collection phase, pigs were switched to the opposite diet that contained chromic oxide.(ABSTRACT TRUNCATED AT 250 WORDS)     

LT348电路的研制

本文介绍了ＬＴ３４８的电路、版图和工艺设计。ＬＴ３４８是由四个功能和７４１组件等同而又各自独立的高增益、内补偿、低功耗运放器组成，并且它的电源电流可以和单个的７４１典型运放器相比拟。此外，它还具有比标准７４正低得多的输入失调电流和输入偏流的特征。