These data add to the growing body of evidence showing that hostility influences vagal modulation of the cardiovascular system and suggest that altered autonomic control is a pathogenic mechanism linking hostility and CAD.

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Abstract-In this paper we investigate sequential decision mechanisms for composite web services. After executing each sub-service within a sequential workflow, decisions are made whether to terminate or continue the execution of the workflow. These decisions are based on observed response times, expected rewards, and typical Service Level Agreement parameters such as costs, penalties, and agreed response-time objectives. We propose a model for the sequential decision-making process within which we explore a couple of decision algorithms. We benchmarked these algorithms against the profit made when executing the workflow without decision-making. We show that algorithm based on backward recursion principle of dynamic programming is optimal with respect to profit. Next, we analyse the structure of erroneous decisions for both algorithms and show that significant profit gains can be obtained by sequential decision making.

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Abstract-Uplink users in cellular networks, such as UMTS/ HSPA, located at the edge of the cell generally suffer from poor channel conditions. Deploying intermediate relay nodes is seen as a promising approach towards extending cell coverage and increasing data rates. This paper focuses on the role of packet scheduling in cellular networks with relay nodes. In particular, two uplink scheduling schemes deploying the relay functionality in different ways are compared in performance to a reference scenario where relaying is not used. We derive expressions which characterize for each of the two relay-enabled schedulers the service area of a relay station as a function of the relay location and transmit power. The results show that the service area is significantly influenced by the type of scheduling. Examining the impact on the effective data rates of mobile stations shows that there is a combination of the relay's position and transmit power which optimizes uplink service. Furthermore, based on calculations of flow throughput, we show that relaying improves flow level performance of all users, including those who do not use the relay.

Advanced packet scheduling schemes in 3G/3G+ mobile networks provide one or more parameters to optimise the trade-off between QoS and resource efficiency. In this paper we study the sensitivity of the optimal parameter setting for packet scheduling in LTE radio networks with respect to various traffic and environment aspects. For our investigations we consider a reference packet scheduling algorithm containing elements of proportional fairness and packet urgency to support mixes of real-time and non-real-time traffic. We present extensive simulation results showing the impact of traffic characteristics (like file size distribution, traffic mix) and environment conditions (regarding e.g. multipath fading and shadowing) on the optimal parameter setting. Although, in some cases, efficiency gains of about twenty percent can be achieved by proper tuning of the scheduling parameters, the overall view from our investigations is that a single, robust setting of the parameters can be determined which provides near optimal trade-offs under almost all practically relevant conditions.

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