Search results for "Congestion"
showing 10 items of 79 documents
The self-reported stress and stressors in tram and long-haul truck drivers
2022
Work stress may compromise professional drivers’ health and driving capacity. Differences between driver groups in terms of on-duty stress are understudied. Therefore, we examined self-reported stress (Stockholm University Stress Scale) of shift-working tram and long-haul truck drivers (n = 75) across 2–3 weeks. Furthermore, stressors were self-reported retrospectively and categorised as related to the job, driving conditions, personal, or other causes. Stress levels were generally low, but moderate to high stress (≥6) was more frequently reported among the tram drivers. Stressors related to the job (54%) and driving conditions (19% of all shifts) were frequently reported among the tram and…
A New Scalable and Cost-Effective Congestion Management Strategy for Lossless Multistage Interconnection Networks
2005
In this paper, we propose a new congestion management strategy for lossless multistage interconnection networks that scales as network size and/or link bandwidth increase. Instead of eliminating congestion, our strategy avoids performance degradation beyond the saturation point by eliminating the HOL blocking produced by congestion trees. This is achieved in a scalable manner by using separate queues for congested flows. These are dynamically allocated only when congestion arises, and deallocated when congestion subsides. Performance evaluation results show that our strategy responds to congestion immediately and completely eliminates the performance degradation produced by HOL blocking whi…
Congestion Avoidance Using DYnamic COdec MAnagement: A solution for ISP
2005
The large diffusion of VoIP is an essential key for the success of emerging Internet service providers. These ISPs conflict with the interests of historical and predominant network maintainers which often control the network infrastructure and telephone services. To win this competition, emerging ISPs have to adopt strategic QoS solutions which will capture the attention of network users and phone clients. This paper presents a solution which is able to obtain the same performance of a 64 Kbps channel reducing the costs for over-provisioning network bandwidth. DyCoMa is a mechanism studied for VoIP applications in network with a limited bandwidth for multimedia services. It works preventing…
Evaluating the Reform of Healthcare System in Sicily: variations of efficiency and appropriateness between 2008 and 2010
2022

 
 Background. Sicilian government has developed a very ambitious Reform through the Regional Law n. 5 (14th April 2009). Hospitals were requested to ensure the quality of care through monitoring of appropriateness and quality of service. The aim of this study was to assess variations of efficiency and organizational appropriateness of healthcare delivery before and after this Reform and to show patterns associated to different types of healthcare delivery organizations.
 Methods. This study was based on repeated cross-sectional data for 118 (out of 129) short-term, acute-care, non teaching-and-research Sicilian hospitals, in 2008 and 2010. Congestion and slacks analysis was…
Architectures and protocols for mobile computing applications: a reconfigurable approach
2004
This work deals with reconfigurable control functions and protocols for supporting mobile computing applications in heterogeneous wireless systems like cellular networks and WLANs. The control functions are implemented in a software module, named Reconfigurable Access module for MObile computiNg applications (RAMON), placed in mobile and/or base stations. RAMON operates on abstract models of the main communication functions of a wireless systems (e.g., transmission over the radio channel, coding end error recovery, capacity sharing and packet scheduling, handover, congestion control, etc.). RAMON algorithms are programmed with reference to the abstract models, independently of specific radi…
A Kalman Filter Approach for Distinguishing Channel and Collision Errors in IEEE 802.11 Networks
2008
In the last years, several strategies for maximizing the throughput performance of IEEE 802.11 networks have been proposed in literature. Specifically, it has been shown that optimizations are possible both at the medium access control (MAC) layer, and at the physical (PHY) layer. In fact, at the MAC layer, it is possible to minimize the channel waste due to collisions and backoff expiration times, by tuning the minimum contention window as a function of the network congestion level. At the PHY layer, it is possible to improve the transmission robustness, by selecting a suitable modulation/coding scheme as a function of the channel quality perceived by the stations. However, the feasibility…
Hidden Markov Model Based Machine Learning for mMTC Device Cell Association in 5G Networks
2019
Massive machine-type communication (mMTC) is expected to play a pivotal role in emerging 5G networks. Considering the dense deployment of small cells and the existence of heterogeneous cells, an MTC device can discover multiple cells for association. Under traditional cell association mechanisms, MTC devices are typically associated with an eNodeB with highest signal strength. However, the selected eNodeB may not be able to handle mMTC requests due to network congestion and overload. Therefore, reliable cell association would provide a smarter solution to facilitate mMTC connections. To enable such a solution, a hidden Markov model (HMM) based machine learning (ML) technique is proposed in …
Randomized placebo-controlled trial comparing fluticasone aqueous nasal spray in mono-therapy, fluticasone plus cetirizine, fluticasone plus monteluk…
2004
BACKGROUND: Corticosteroids are considered to be particularly effective in reducing nasal congestion and are therefore recommended as first-line treatment in allergic rhinitis patients with moderate to severe and/or persistent symptoms. OBJECTIVE: We compared the clinical efficacy of fluticasone propionate aqueous nasal spray (FPANS) 200 microg given once daily, administered in mono-therapy or combined therapy with a H1 receptor antagonist (cetirizine, CTZ) or with a leukotriene antagonist (montelukast, MSK), and the combined therapy of CTZ plus MSK in the treatment of patients affected by allergic rhinitis to Parietaria during natural pollen exposure. In addition, we examined the effect of…
Evaluation of a Computer Vision Based Automatic Incident and Congestion Detection System in an Urban Context
1994
Abstract The objective of the document is to describe an Automatic Incident and Congestions Detection System based on computer vision technology, in an urban environment. The document outlines the main technical features of the system and presents the first evaluation results obtained in a field trial currently carried out in protect INVAII) II. within the Transport Telematics Programme of the EC. CCTV cameras are installed in urban street intersections lor surveillance purposes. Based on image processing techniques. the Video Analyzers or Local Sensor Modules (LSM) connected to a number of selected cameras, obtain the traffic status measurements within the field of view of each one of them…
AIOC2: A deep Q-learning approach to autonomic I/O congestion control in Lustre
2021
Abstract In high performance computing systems, I/O congestion is a common problem in large-scale distributed file systems. However, the current implementation mainly requires administrator to manually design low-level implementation and optimization, we proposes an adaptive I/O congestion control framework, named AIOC 2 , which can not only adaptively tune the I/O congestion control parameters, but also exploit the deep Q-learning method to start the training parameters and optimize the tuning for different types of workloads from the server and the client at the same time. AIOC 2 combines the feedback-based dynamic I/O congestion control and deep Q-learning parameter tuning technology to …