Editorial

Systemic Practice and Action Research -     

Editorial

Systemic Practice and Action Research -     

Editorial

Systemic Practice and Action Research -     

Performance analysis of optimal channel estimation and multiuser detection in a randomly-spread CDMA channel

<正> This paper analyzes performance of optimal channel estimation and multiuser detection(MUD) in a block-fading code-division multiple-access (CDMA) channel on the assumptions of randomspreading and large-system limit,by using the replica method developed in statistical mechanics.The authors find that the asymptotic spectral efficiency of the linear minimum mean-squared error(LMMSE) MUD which was proposed and analyzed by Evans and Tse in 2000 is indistinguishable fromthat of the optimal MUD for small system loads.Our results imply that performance of MUD scarcelyimproves even if one spends more computational cost than that of the LMMSE MUD,i.e.,at most thecube of the number of users,on the above-described conditions.     

An analytic hierarchy process model of group consensus

In group decision making, a certain degree of consensus is necessary to derive a meaningful and valid outcome. This paper proposes a consensus reaching model for a group by using the Analytic Hierarchy Process （AHP）. It supports people to improve their group consensus level through an updating of their judgments. In this model, a moderator suggests the most discoraant aeclslon manet to update his judgment in each step. The proposed consensus reaching model allows decision makers to accept or reject the suggestion from the moderator. This model ensures that the judgment updating is effective and the final solution will be of acceptable consistency. Finally, a numerical example is given to illustrate the validity of the proposed consensus reaching model.     

带有偏好锥的样本数据包络分析方法研究

针对传统数据包络分析方法无法依据确定参考面提供评价信息的弱点,给出了带有偏好锥的样本数据包络分析模型(PSam-C2WH)和相应的SCDEA有效性及弱有效性概念。分析了(PSam-C2WH)模型的性质以及它与传统DEA模型之间的关系,探讨了(PSam-C2WH)模型刻画的SCDEA有效性及弱有效性与相应的多目标规划非支配解之间的关系。进而,分析了决策单元在样本可能集中的分布特征、投影性质和模型含义等问题。     

Gd2O3：Dy^3＋纳米晶的制备和发光性质研究

以Gd2O3和Dy2O3为反应物,共沉淀合成了镝掺杂氧化钆纳米粉体．研究了Gd2O3：D6^3＋的光致发光性质随着Dy^3＋掺杂浓度和煅烧温度的变化关系．通过对荧光强度与激活离子Dy^3＋离子浓度的关系研究发现,Dy^3＋在纳米Gd2O3基质中存在浓度猝灭现象,最佳掺杂浓度为0．7％．     

河南省普通高校排球运动现状的调查研究

采用文献资料法、问卷调查法、访谈法和数理统计等方法,调查了河南省普通高校排球运动的现状,对其影响因素进行了分析.结果表明,影响排球运动开展的因素主要是项目自身特点、大学生参与排球运动的动机、场地设备欠缺、领导重视不够等,并对如何推动河南省普通高校排球运动的开展及提高排球运动水平提出了可行性建议.     

Marrow mesenchymal stem cells transduced with TPO/FL genes as support for ex vivo expansion of hematopoietic stem/progenitor cells

A new marrow-derived mesenchymal stem cell (hMSC) line that could support expansion of hematopoietic stem/progenitor cells (HSPCs) was developed. Primary hMSCs were infected with retrovirus containing Flt-3 ligand and thrombopoietin genes. CD34+ cells from cord blood were expanded with primary hMSCs or transduced hMSCs. The expansion of total nucleated cells, CD34+ cells and mixed colonies containing erythroid and myeloid cells and megakaryocytes for 2 weeks coculture with transduced hMSCs was remarkably increased. The outputs of long-term culture-initiating cells for 2 and 4 weeks coculture with transduced hMSCs were also largely increased. The expansion rates of HSPCs with transduced hMSCs were unchanged for 6 weeks. In contrast, the expansion rates of HSPCs with primary hMSCs declined drastically through 6 weeks. SCID-repopulating cell expansion with transduced hMSCs for 4 weeks was significantly higher than that of uncultured CD34+ cells and HSPCs expanded with primary hMSCs. Received 21 June 2005; received after revision 30 July 2005; accepted 24 August 2005     

Copper and zinc dismetabolism in the mouse brain upon chronic cuprizone treatment

Recent reports describe successful treatment using copper chelation therapy in neurodegenerative animal models. However, the success claimed for chelation therapy in neurodegenerative diseases is still rather controversial. To acquire new information on copper metabolism/homeostasis, we utilized cuprizone, a very sensitive and selective copper-chelating agent with well-known neurotoxic properties, as a relevant chemical model in mice. Upon cuprizone treatment, mice developed a pronounced astrocytosis, with brain oedema and spongiosis characterised by vacuolisations of the neuropil predominantly in the white matter. In addition, cuprizone treatment severely altered copper and zinc homeostasis in the central nervous system (CNS) as well as in all other tissues examined, with increasing metal ion concentrations particularly in the CNS. Concomitant with this increase in the Cu and Zn concentration in the brain, metallothionein-I and -II were also highly immunoreactive in astrocyte, consistent with the astrocytosis and demyelination observed in our and other laboratories.Received 23 February 2005; received after revision 3 May 2005; accepted 13 May 2005