This paper presented an idea to replace the traditionally expensive parallel machines by heterogeneous cluster of workstations. To emphasise the usability of cluster of workstations platform for parallel and distribut...This paper presented an idea to replace the traditionally expensive parallel machines by heterogeneous cluster of workstations. To emphasise the usability of cluster of workstations platform for parallel and distributed computing, also the paper presented the status report on the effort and experiences for the implementation of a dynamic load balancing for parallel tree computation depth first search(DFS) on the cluster of a workstations project. It compared the speedup performance obtained from our platform with that obtained from the traditional one. The speedup results show that cluster of workstations can be a serious alternative to the expensive parallel machines.展开更多
The antenna geometry strategy for direction finding （DF） with multiple-input multiple-output （MIMO） radars is studied. One case, usually encountered is practical applications, is consi- dered. For a directional an...The antenna geometry strategy for direction finding （DF） with multiple-input multiple-output （MIMO） radars is studied. One case, usually encountered is practical applications, is consi- dered. For a directional antenna geometry with a prior direction, the trace-optimal （TO） criterion （minimizing the trace） on the av- erage Cramer-Rao bound （CRB） matrix is employed. A qualitative explanation for antenna geometry is provided, which is a combi- natorial optimization problem. In the numerical example section, it is shown that the antenna geometries, designed by the proposed strategy, outperform the representative DF antenna geometries.展开更多
The real problem in cluster of workstations is the changes in workstation power or number of workstations or dynmaic changes in the run time behavior of the application hamper the efficient use of resources. Dynamic l...The real problem in cluster of workstations is the changes in workstation power or number of workstations or dynmaic changes in the run time behavior of the application hamper the efficient use of resources. Dynamic load balancing is a technique for the parallel implementation of problems, which generate unpredictable workloads by migration work units from heavily loaded processor to lightly loaded processors at run time. This paper proposed an efficient load balancing method in which parallel tree computations depth first search (DFS) generates unpredictable, highly imbalance workloads and moves through different phases detectable at run time, where dynamic load balancing strategy is applicable in each phase running under the MPI(message passing interface) and Unix operating system on cluster of workstations parallel platform computing.展开更多
目的:比较乳腺腺样囊性癌(adenoid cystic carcinoma of the breast,ACCB)与三阴性浸润性导管癌(invasive ductal carcinoma,IDC)临床病理特征及预后。方法:分析2004年1月至2020年12月就诊于中国医学科学院肿瘤医院的26例ACCB与216例三...目的:比较乳腺腺样囊性癌(adenoid cystic carcinoma of the breast,ACCB)与三阴性浸润性导管癌(invasive ductal carcinoma,IDC)临床病理特征及预后。方法:分析2004年1月至2020年12月就诊于中国医学科学院肿瘤医院的26例ACCB与216例三阴性IDC患者的临床病理资料。采用Kaplan-Meier法绘制无疾病生存(disease free survival,DFS)和总生存(overall survival,OS)曲线,Log-rank法进行组间比较。结果:中位随访时间72.4个月,4例ACCB患者出现复发转移,肺和肝是常见的转移部位。与IDC相比,ACCB的发病年龄>60岁、Ki-67低表达、神经侵犯、分期早(Ⅰ期和Ⅱ期)、无淋巴结转移的比例更高(P<0.05)。与IDC相比,ACCB患者的5年DFS率和OS率有获益趋势,但差异无统计学意义。Ki-67低表达ACCB患者的中位DFS显著高于Ki-67高表达者(χ^(2)=4.633,P=0.031)。无神经侵犯的患者较有神经侵犯者的DFS显著改善(χ^(2)=3.861,P=0.049)。结论:Ki-67高表达和神经侵犯是ACCB复发转移的危险因素。与三阴性IDC相比,ACCB具有Ki-67低表达、神经侵犯、腋窝淋巴结阴性、分期早的临床病理特点和以保乳术为主、不行辅助化疗的治疗方式。展开更多
基金National Science Foundation of China(No.60 173 0 3 1)
文摘This paper presented an idea to replace the traditionally expensive parallel machines by heterogeneous cluster of workstations. To emphasise the usability of cluster of workstations platform for parallel and distributed computing, also the paper presented the status report on the effort and experiences for the implementation of a dynamic load balancing for parallel tree computation depth first search(DFS) on the cluster of a workstations project. It compared the speedup performance obtained from our platform with that obtained from the traditional one. The speedup results show that cluster of workstations can be a serious alternative to the expensive parallel machines.
基金supported by the National Natural Science Foundation of China(6107211761302142)
文摘The antenna geometry strategy for direction finding （DF） with multiple-input multiple-output （MIMO） radars is studied. One case, usually encountered is practical applications, is consi- dered. For a directional antenna geometry with a prior direction, the trace-optimal （TO） criterion （minimizing the trace） on the av- erage Cramer-Rao bound （CRB） matrix is employed. A qualitative explanation for antenna geometry is provided, which is a combi- natorial optimization problem. In the numerical example section, it is shown that the antenna geometries, designed by the proposed strategy, outperform the representative DF antenna geometries.
基金Natural Science Foundation of China (No.60 173 0 3 1)
文摘The real problem in cluster of workstations is the changes in workstation power or number of workstations or dynmaic changes in the run time behavior of the application hamper the efficient use of resources. Dynamic load balancing is a technique for the parallel implementation of problems, which generate unpredictable workloads by migration work units from heavily loaded processor to lightly loaded processors at run time. This paper proposed an efficient load balancing method in which parallel tree computations depth first search (DFS) generates unpredictable, highly imbalance workloads and moves through different phases detectable at run time, where dynamic load balancing strategy is applicable in each phase running under the MPI(message passing interface) and Unix operating system on cluster of workstations parallel platform computing.
