The communication processor of TUMULT-64

Tumult (Twente University MULTi-processor system) is a modular extendible multi-processor system designed and implemented at the Twente University of Technology in co-operation with Oce Nederland B.V. and the Dr. Neher Laboratories (Dutch PTT). Characteristics of the hardware are: MIMD type, distributed memory, message passing, high performance, real-time and fault tolerant. A distributed real-time operating system has been realized, consisting of a multi-tasking kernel per node, inter process communication via typed messages and a distributed file system. In this paper first a brief description of the system is given, after that the architecture of the communication processor will be discussed. Reduction of the communication overhead due to message passing will be emphasized.\ud \u

Throughput of Streaming Applications Running on a Multiprocessor Architecture

We study the timing behaviour of streaming applications running on a multiprocessor architecture. Dependencies are derived between the application throughput and the timing characteristics of the processors and communication. Four different processor organizations that strongly influenced the results are considered and compared

Efficient Inter-Task Communication for Nested Loop Programs on a Multiprocessor System

In modern multiprocessor systems, processors can be stalled by inter-task communication when reading from a remote buffer. This paper presents a solution for the inter-task communication, that has a minimal impact on the performance of the system, hides the inter-task communication latency without requiring additional hardware. The solution applies to jobs, represented as task graphs, where the tasks are nested loop programs. Buffers are allocated in scratch-pad memories of the consuming tasks to provide low latency read access. For the nested loop programs, minimal buffer sizes can be determined to cover all possible communication patterns. The added computational complexity is low, as the solution adds only a few operations to the nested loop programs

Architecture Design Space Exploration for Streaming Applications Through Timing Analysis

In this paper we compare the maximum achievable throughput of different memory organisations of the processing elements that constitute a multiprocessor system on chip. This is done by modelling the mapping of a task with input and output channels on a processing element as a homogeneous synchronous dataflow graph, and use maximum cycle mean analysis to derive the throughput. In a HiperLAN2 case study we show how these techniques can be used to derive the required clock frequency and communication latencies in order to meet the application's throughput requirement on a multiprocessor system on chip that has one of the investigated memory organisations

On hardware for generating routes in Kautz digraphs

In this paper we present a hardware implementation of an algorithm for generating node disjoint routes in a Kautz network. Kautz networks are based on a family of digraphs described by W.H. Kautz[Kautz 68]. A Kautz network with in-degree and out-degree d has N = dk + dk¿1 nodes (for any cardinals d, k>0). The diameter is at most k, the degree is fixed and independent of the network size. Moreover, it is fault-tolerant, the connectivity is d and the mapping of standard computation graphs such as a linear array, a ring and a tree on a Kautz network is straightforward.\ud The network has a simple routing mechanism, even when nodes or links are faulty. Imase et al. [Imase 86] showed the existence of d node disjoint paths between any pair of vertices. In Smit et al. [Smit 91] an algorithm is described that generates d node disjoint routes between two arbitrary nodes in the network. In this paper we present a simple and fast hardware implementation of this algorithm. It can be realized with standard components (Field Programmable Gate Arrays)

The predictive values of a deliberative and a paternalistic attitude towards two situations of moral conflict:A study among Dutch nurse practitioners and physician assistants

Background In this study, we examined the predictive values of a moral deliberate and paternalistic attitude on the propensity of yielding to pressure. In these hypothesised positive and negative relationships, we further sought to ascertain whether moral disengagement plays a pivotal role when individuals deviate from ethical standards, rules and regulations when yielding to pressure. Aim(s) This study's primary aim was to assess the predictive value of a moral deliberative and paternalistic attitude for yielding to pressure when physician assistants (PAs) and nurse practitioners (NPs) face moral conflicts. Method This validation study was cross-sectional and based on a convenience sample of Dutch PAs and NPs. The MSQ-DELIB and MSQ-PATER scales indicate a moral deliberate or paternalistic attitude. These scales were assumed to have a predictive value towards the degree of yielding to pressure by PAs and NPs. Yielding to pressure was measured by two vignettes in which respondents faced a moral conflict (vignette 1: prescribing unindicated antibiotics and vignette 2: discharging a difficult patient from the hospital). Results Only moral deliberation was a significant predictor of yielding to pressure. That is, we found a positive effect in vignette 1 (in which the pressure came from the patient). In contrast, we found a negative relationship in vignette 2 (in which pressure went from the working environment). Paternalism did not affect yielding to pressure in either vignette. Conclusion This study suggests that PAs and NPs having a moral deliberative attitude makes them receptive to pressure exerted by patients to break moral standards. On the other hand, they are more resilient against doing so when this pressure comes from different sources than the patient. Further research is needed to find more conclusive evidence for this differential effect

Evidence Based Studies in Clinical Transfusion Medicine

After the introduction of blood component therapy in the 1960s, more and more attention is given to clinical transfusion medicine. Although blood transfusion is an important treatment in different clinical settings, there are still lack of much randomized clinical trials. Nowadays blood transfusion can be called a safe treatment. This might be due to an increasing awareness of the effects and risks of blood transfusion. In clinical transfusion practice a transfusion trigger is handled for the prescription of blood transfusion. This transfusion trigger is based on hemoglobin (Hb) levels for red blood cell (RBC) transfusion and on platelet count for platelet transfusions. Possibilities to improve the safety of blood transfusion are improvement of the blood components and reduction of the amount of blood transfusions. This thesis describes 1) an in vitro study of a new pathogen technique for platelet concentrates and 2) a new model for RBC transfusion therapy for acute anemia. This model uses subjective health related quality of life criteria, which are validated in this thesis