Introduction ATM variable bit rate (VBR) service provides a statistical multiplexing gain and supports guaranteed quality of service through preventive congestion control techniques. However, to do this it requires the source to accurately predict its traffic parameters at call admission time. For stored video, this a priori estimation of traffic characteristics is straightforward; the traffic ...

this prospective longitudinal study deals with the associations between digital disorders and reproduction indices in dairy cattle on a farm in the vicinity of tehran. it was carried out on 225 postparturient holstein heifers. the evaluation of lameness due to digital disorders on postpartum period of heifers were done and after diagnosis of lameness (based on a 5 points lameness scoring system...

Today’s market share of Intelligent Network (IN) service is growing rapidly in wireless networks due to the rapid advances in wireless telecommunication and IN technology. To guarantee network independent IN services, mobility of IN service subscribers has to be taken into account. This paper proposes new designs of Global Service Logic for the IN service enhancement, which increase call comple...

Packet scheduling methods that approximate Generalized Processor Sharing (GPS) are currently the focus of much research in the area of Quality-of-Service (QoS) networks. The ability of GPS schedulers to provide rate guarantees as well as delay guarantees meets the demand of many network applications. This paper addresses a shortcoming of GPS which can have signiicant impact on the service provi...

This paper employs sample path arguments to derive the following convexity properties and comparative statics for an M/M/S queue with impatient customers. If the rate at which customers balk and renege is an increasing, concave function of the number of customers in the system (head-count), then the head-count process and the expected rate of lost sales are decreasing and convex in the capacity...

In this paper, we present a priority scheduling algorithm at ATM switches with multi-class output buffers in which the service rate of each class buffer is dynamically adjusted. The service rate is computed periodically by a control scheme. We derive the design formulas of the control scheme to ensure that each class buffer occupancy converges to its desired operating point related to QoS requi...

In this paper, the rate-based congestion control algorithm that has been standardized in the ATM Forum is evaluated. Its behavior is analyzed by utilizing a firstorder fluid approximation to provide control parameter tuning. We obtain the maximum queue length at the switch and conditions for avoiding under-utilization. The results are then applied to TCP over ABR service class. More specificall...

In this paper we analyze stable fluid vacation models with exhaustive discipline, in which the fluid source is modulated by a background continuous-time Markov chain and the fluid is removed at constant rate during the service period. Due to the continuous nature of the fluid the state space of the model becomes continuous, which is the major novelty and challenge of the analysis. We adapt the ...

background and objectives: neisseria meningitidis is transmitted from person-to-person. thus, close contact with a healthy carrier can facilitate the spread of the bacteria and lead to life-threatening meningococcal disease. the aim of this study was to identify oropharyngeal carriers of n. meningitidis in volunteers preparing for military service before vaccination. materials and methods: in a...

This paper considers a Geo/Geo/1 queueing system with infinite capacity, in which the service rate changes depending on the workload. Initially, when the number of customers in the system is less than a certain threshold L, low service rate is provided for cost saving. On the other hand, the high service rate is activated as soon as L customers accumulate in the system and such service rate is ...