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
Objective: The aim of the study was to determine the efficiency and effectiveness of picture archiving and communication system(PACS) workstation in detecting enhancement pattern of peripheral bronchogenic carcinoma. ...Objective: The aim of the study was to determine the efficiency and effectiveness of picture archiving and communication system(PACS) workstation in detecting enhancement pattern of peripheral bronchogenic carcinoma. Methods: The 62 patients with peripheral bronchogenic carcinoma underwent two-phase contrast material-enhanced multislices computed tomography(MSCT) of the chest in a single-breath-hold technique. Two spiral CT scans were obtained at 25 s and 90 s respectively after nonionic contrast material was administrated via the antecubital vein at a rate of 4 m L/s by using an autoinjector. Precontrast and postcontrast attenuation on every scan were measured on PACS and CT workstations respectively and peak height was calculated. Enhancement pattern was evaluated on the image obtained at 90 s after injection of contrast medium on PACS and CT workstations respectively. Results: No statistically significant difference in precontrast attenuation, postcontrast attenuation at 25 s and 90 s was found between these measured on a PACS workstation [(40.21 ± 7.03) HU;(55.53 ± 11.09) HU;(75.95 ± 13.45) HU] and those [(39.01 ± 8.95) HU;(56.01 ± 10.91) HU;(76.03 ± 11.95) HU] on a CT workstation(t = 1.140, P = 0.256 > 0.05; t = 1.580, P = 0.149 > 0.05; t = 1.505, P = 0.150﹥0.05). The peak height that calculated on a PACS workstation was 35.74 HU(20 HU). There was not statistically significant difference in peak height between that calculated on a PACS workstation and that on a CT workstation [(37.02 ± 12.05) HU; t = 2.001, P = 0.099 > 0.05]. The tumors showed same enhancement pattern on PACS workstation and CT workstation. Of the 62 cases, 38 showed homogeneous enhancement, 17 showed heterogeneous enhancement, five showed peripheral enhancement, two showed central enhancement, at 90 s. The enhancement pattern revealed on PACS workstation was consistent with feature of peripheral bronchogenic carcinoma. Conclusion: The efficiency and effectiveness of PACS workstation is as same as those of CT workstation in detecting enhancement pattern of peripheral bronchogenic carcinoma.展开更多
Network of workstations (NOW) now becomes one of the main trends of parallel computing. But for long-running scientific programs, it needs effective fault tolerance for its changing property. Checkpointing and rollbac...Network of workstations (NOW) now becomes one of the main trends of parallel computing. But for long-running scientific programs, it needs effective fault tolerance for its changing property. Checkpointing and rollback recovery is a solution to this problem. First the main problems upon rollback recovery are discussed, the different checkpointing techniques for NOW are analyzed, and then the design and implementation of ChaRM (checkpoint-based rollback recovery and process migration) system are described. The comparison of three coordinated checkpointing systems is given.展开更多
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.
文摘Objective: The aim of the study was to determine the efficiency and effectiveness of picture archiving and communication system(PACS) workstation in detecting enhancement pattern of peripheral bronchogenic carcinoma. Methods: The 62 patients with peripheral bronchogenic carcinoma underwent two-phase contrast material-enhanced multislices computed tomography(MSCT) of the chest in a single-breath-hold technique. Two spiral CT scans were obtained at 25 s and 90 s respectively after nonionic contrast material was administrated via the antecubital vein at a rate of 4 m L/s by using an autoinjector. Precontrast and postcontrast attenuation on every scan were measured on PACS and CT workstations respectively and peak height was calculated. Enhancement pattern was evaluated on the image obtained at 90 s after injection of contrast medium on PACS and CT workstations respectively. Results: No statistically significant difference in precontrast attenuation, postcontrast attenuation at 25 s and 90 s was found between these measured on a PACS workstation [(40.21 ± 7.03) HU;(55.53 ± 11.09) HU;(75.95 ± 13.45) HU] and those [(39.01 ± 8.95) HU;(56.01 ± 10.91) HU;(76.03 ± 11.95) HU] on a CT workstation(t = 1.140, P = 0.256 > 0.05; t = 1.580, P = 0.149 > 0.05; t = 1.505, P = 0.150﹥0.05). The peak height that calculated on a PACS workstation was 35.74 HU(20 HU). There was not statistically significant difference in peak height between that calculated on a PACS workstation and that on a CT workstation [(37.02 ± 12.05) HU; t = 2.001, P = 0.099 > 0.05]. The tumors showed same enhancement pattern on PACS workstation and CT workstation. Of the 62 cases, 38 showed homogeneous enhancement, 17 showed heterogeneous enhancement, five showed peripheral enhancement, two showed central enhancement, at 90 s. The enhancement pattern revealed on PACS workstation was consistent with feature of peripheral bronchogenic carcinoma. Conclusion: The efficiency and effectiveness of PACS workstation is as same as those of CT workstation in detecting enhancement pattern of peripheral bronchogenic carcinoma.
基金Project supported by the National "863" High-tech Program of China.
文摘Network of workstations (NOW) now becomes one of the main trends of parallel computing. But for long-running scientific programs, it needs effective fault tolerance for its changing property. Checkpointing and rollback recovery is a solution to this problem. First the main problems upon rollback recovery are discussed, the different checkpointing techniques for NOW are analyzed, and then the design and implementation of ChaRM (checkpoint-based rollback recovery and process migration) system are described. The comparison of three coordinated checkpointing systems is given.
