A blind adaptive reduced-rank receiver for ultra-wideband communication systems

A low-complexity blind adaptive receiver for ultra-wideband (UWB) systems in the presence of both multiple access interference (MAI) and inter symbol interference (ISI) is proposed, which is composed of two stages. In the first stage, a reduced-rank algorithm based on the multi-stage Wiener filter (MSWF) is considered to suppress the MAI and extract multi-path components. Channel estimation using the projection approximation subspace tracking with deflation (PASTd) algorithm and multi-path combining are then performed to further enhance the signal to interference plus noise ratio (SINR) of the desired user in the second stage. The simulation results show that the proposed receiver exhibits reasonably good bit error ratio (BER) performance compared with those of matched filter, conventional Rake receiver, decorrelating Rake receiver and adaptive receiver based on constant modulus algorithm (CMA). Moreover, it has faster convergence speed and less complexity.     

基于小波变换的自适应多用户检测算法

在分析传统自适应多用户检测的基础上 ,提出了一种基于小波变换的自适应多用户检测算法。用小波变换进行前处理 ,然后再通过 LMS算法实现自适应多用户检测。与通常的自适应多用户检测算法相比 ,该算法利用了小波变换对小波空间进行了分解 ,信号经小波变换后自相关性会下降 ,收敛速度提高。同时在此分解过程中 ,根据信号与白噪声在不同尺度上的小波变换模极大值表现完全不同的特性进行信号的消噪。理论分析和仿真结果表明 ,该算法收敛速度较快 ,计算量增加较少 ,易于实时实现 ,而且具有良好性能。同时仿真实验表明 ,收敛速度与小波基选择有关 ,对于同一小波基系列 ,小波基的正则性越好收敛速度越快     

西双版纳普文实验林场西南桦人工林的生长研究

对11~13年生西南桦纯林(初植密度包括2 m×2 m,2 m×3 m,2 m×4 m,2 m×5 m,2 m×6 m,3 m×3 m和2 m×3 m×7 m)、12年生西南桦与高阿丁枫(初植密度2 m×3m)和11年生西南桦(初植密度3 m×3 m)与山桂花(初植密度3 m×1.5 m)混交林的生长分析显示,西南桦造林后迅速进入速生期。7年生前尤为速生,速生期可延续至10年生林分,在速生期内,平均木的胸径、树高和木材年平均生长量分别为1.17~2.50 cm.yr-1、1.20~3.60 m.yr-1和0.000 11~0.018 04 m3.yr-1,其连年生长量分别为0.50~2.65 cm.yr-1、0.5~4.0 m.yr-1和0.000 11~0.018 68 m3.yr-1。西南桦纯林中,2 m×5 m和2 m×4 m的初植密度较为有利于林木生长和木材生产,其13年生林分生长量分别达:(1)年平均胸径1.42 cm.yr-1和1.72 cm.yr-1,年平均树高1.77 m.yr-1和1.72 m.yr-1;(2)单位面积材积为209.807 1 m3.hm-2和208.933 8 m3.hm-2,并且胸径>16 cm的林木分别占80.00%和60.00%。混交林的木材产量:(1)12年生西南桦与高阿丁枫混交林单位面积木材产量是同林龄西南桦纯林(初植密度2 m×3 m×7 m)的1.845倍(172.363 7 m3.hm-2比94.978 9 m3.hm-2);(2)11年生西南桦与山桂花混交林单位面积木材产量是同林龄西南桦纯林的2.774倍(158.742 0m3.hm-2比57.219 0 m3.hm-2)。在西南桦与高阿丁枫混交林中,1行西南桦与2行高阿丁枫混交模式能提高西南桦高生长和木材产量。高阿丁枫和山桂花是可以同西南桦相匹配营造混交林的两个云南热带乡土树种。     

猪肉质性状基因及其遗传标记的研究进展

猪肉品质改良是当今遗传育种界的研究热点之一。利用候选基因策略寻找影响肉质性状的主效基因或与其紧密连锁的分子标记 ,并将MAS和MAI策略应用于猪的肉质改良 ,从遗传基础上讲是可行的。本文概述了与猪肉质性状有关的基因的结构特点、作用机制、基因座的定位及其近期研究进展 ,介绍了基因遗传标记的研究与应用策略 ,同时探讨了猪肉质性状研究中存在的问题及研究的方向和前景。     

Partnership Building for Sustainable Development: A First Nations Perspective from Ontario

Abstract

First Nations' approaches toward environmental stewardship have always been based upon partnership and a sense of belonging within the natural environment. The cornerstone of traditional community relationships is the three-pronged model of partnership building, known to the hoquois nations as the “Zeal to Deal.” The Rastern Ontario Model Forest (EOMF) was initiated as one often model forest sites across Canada, under a federal sustainable development initiative. The Eastern Onlario Model Forest was formed from people with many different viewpoints, ideals, tools, and ideas. A mixture of people holding local landowner values. native philosophies, and scientific knowledge were brought together to develop a working partnership at a community level. This presentation will analyze approaches in facilitating a partnership according to traditional knowledge of the Iroquois nations (University of Ottawa, 1994). This presentation will show an analysis of the working relationships of people and organizations according to tools developed and practiced by Aboriginal peoples of Eastern Ontario. These tools include the inclusion of each partner in the Eastern Ontario Model Forest as a full partnership based on the “Zeal to Deal.” The development of partnerships from the use of all three tools in this community-level organization will be analyzed. Challenges in the development of new partnerships, and limitations of partnerships according to naturalized knowledge systems will be analyzed. The strength of the EOMF organization based on its diversity will also be addressed.     

"麦松散"对肉牛增重和血清生化指标的影响

为了解“麦松散”的饲用效果,选择10头年龄、体重相近的本地黄牛×西门达尔牛杂交一代公牛,随机分为对照组和试验组,每组各5头。对照组饲喂基础日粮,试验组在基础日粮中每天添加100g的“麦松散”,连续饲喂30d。试验前(0d)和试验结束时(30d),颈静脉采血测定其血清生化指标值。结果表明:试验组牛与对照组相比,平均日增重增加0.053kg、提高7.31%(P<0.05)、血清葡萄糖(Glu)、总蛋白(TP)、总钙(Ca)含量升高(P<0.05);血清尿素(Urea)浓度降低(P<0.05);血清球蛋白(GLOB)、无机磷(P)、钾(K)、钠(Na)离子浓度变化差异不显著(P>0.05)。结论:“麦松散”对肉牛有明显的促生长作用,并能改善其部分血清生化指标值。     

Eucalyptus plantations in Israel: an assessment of economic and environmental viability

This paper discusses a plantation management approach involving a combination of “short” and “long” rotations designed to allow farmers to receive income from trees as soon as possible after establishment. We present results from two plots that represent extreme conditions: (a) a seasonally waterlogged, non-saline site (Nahalal), and (b) a saline site (Ginnegar) located in the Yizre’el Valley, Israel. Six improved seed sources, four of Eucalyptus camaldulensis and two of E. occidentalis, were examined. The local Israeli seed source of E. camaldulensis (HA) performed best at both sites. In Nahalal, the short rotation thinning of the slower growing (50%) plantation trees could provide economic returns approximately five years after establishment. The calculated mean annual increment (MAI) of these trees reached 12.2 t ha⁻¹ year⁻¹. The long rotation, or better performing half of the plantation trees, could be used as a source of sawn timber, providing higher-value products. By nine years after establishment, the average DBH of the various seed sources reached 25.8 ± 1.9 cm. The calculated MAI of the combined cutting rotations reached 48.3 t ha⁻¹ year⁻¹. Eucalyptus grown under the combined (short- and long-term) management approach at Nahalal was more profitable than many other non-irrigated local crops. Eucalyptus production in Ginnegar would be less profitable than in Nahalal. However, an additional ecological benefit was provided by the crop’s ability to lower the water table. When this contribution to regional drainage is taken into account, trees become economically competitive with other non-irrigated field crops under saline conditions. Jim Morris–Deceased.     

A Data Detector Based on Channel Equalizer Designed for the Downlink of CDMA Systems

In code-division multiple-access (CDMA) systems,sub-optimum multi-user or joint detection algorithms have been studied recently, which are mostly designed for the uplink situation. The algorithms are too complex to implement for the downlink situation. The conventional receiver consisting of matched filters is often inefficient in eliminating MAI. The authors propose a data detection algorithm designed for downlink of CDMA systems which introduce channel equalization to eliminate MAI. It consists of a channel equalizer and code matched filter. The equalization algorithm is based on zero forcing (ZF) criterion.The performance of the algorithm is better than metched filter's and its complexity is cower than tunt of sub-optimum multi-user detection.