Capacity management of CT department with service time differences and emergency nonpreemptive priority

Author(s):  
Jie Zhou ◽  
Peng Guo
Author(s):  
Jaber Almutairi ◽  
Mohammad Aldossary

AbstractRecently, the number of Internet of Things (IoT) devices connected to the Internet has increased dramatically as well as the data produced by these devices. This would require offloading IoT tasks to release heavy computation and storage to the resource-rich nodes such as Edge Computing and Cloud Computing. Although Edge Computing is a promising enabler for latency-sensitive related issues, its deployment produces new challenges. Besides, different service architectures and offloading strategies have a different impact on the service time performance of IoT applications. Therefore, this paper presents a novel approach for task offloading in an Edge-Cloud system in order to minimize the overall service time for latency-sensitive applications. This approach adopts fuzzy logic algorithms, considering application characteristics (e.g., CPU demand, network demand and delay sensitivity) as well as resource utilization and resource heterogeneity. A number of simulation experiments are conducted to evaluate the proposed approach with other related approaches, where it was found to improve the overall service time for latency-sensitive applications and utilize the edge-cloud resources effectively. Also, the results show that different offloading decisions within the Edge-Cloud system can lead to various service time due to the computational resources and communications types.


2018 ◽  
Vol 42 (4) ◽  
pp. 438
Author(s):  
Kathryn Zeitz ◽  
Darryl Watson

Objective The aim of the paper was to describe a suite of capacity management principles that have been applied in the mental health setting that resulted in a significant reduction in time spent in two emergency departments (ED) and improved throughput. Methods The project consisted of a multifocal change approach over three phases that included: (1) the implementation of a suite of fundamental capacity management activities led by the service and clinical director; (2) a targeted Winter Demand Plan supported by McKinsey and Co.; and (3) a sustainability of change phase. Descriptive statistics was used to analyse the performance data that was collected through-out the project. Results This capacity management project has resulted in sustained patient flow improvement. There was a reduction in the average length of stay (LOS) in the ED for consumers with mental health presentations to the ED. At the commencement of the project, in July 2014, the average LOS was 20.5 h compared with 8.5 h in December 2015 post the sustainability phase. In July 2014, the percentage of consumers staying longer than 24 h was 26% (n = 112); in November and December 2015, this had reduced to 6% and 7 5% respectively (less than one consumer per day). Conclusion Improving patient flow is multifactorial. Increased attendances in public EDs by people with mental health problems and the lengthening boarding in the ED affect the overall ED throughput. Key strategies to improve mental health consumer flow need to focus on engagement, leadership, embedding fundamentals, managing and target setting. What is known about the topic? Improving patient flow in the acute sector is an emerging topic in the health literature in response to increasing pressures of access block in EDs. What does this paper add? This paper describes the application of a suite of patient flow improvement principles that were applied in the mental health setting that significantly reduced the waiting time for consumers in two EDs. What are the implications for practitioners? No single improvement will reduce access block in the ED for mental health consumers. Reductions in waiting times require a concerted, multifocal approach across all components of the acute mental health journey.


1989 ◽  
Vol 106 ◽  
pp. 367-367
Author(s):  
Ian Griffin ◽  
C.J. Skinner ◽  
B.R. Whitmore

We present near IR (H, K and L band) medium resolution (ƛ/Δƛ ∼ 600) spectra for a selection of 9 red giants which have previously been shown to exhibit anomalous dust emission as characterised by their IRAS LRS spectra. The objects observed (during UKIRT and AAT service time) include Carbon stars whose LRS spectra show the 9.7μm silicate feature and also M stars whose LRS spectra display an 11.3μm feature similar to that usually associated with emission from SiC dust grains.


Author(s):  
Naser Shabakhty ◽  
Pieter van Gelder ◽  
Hotze Boonstra

Generally, jack-up structures are used for production drilling and exploration of hydrocarbons. The combination of mobility and the behavior as a fixed structure in operational conditions has made it an important structure in the offshore industry over the last 40 years. When a jack-up structure has been in operation for a great part of its original design-life and intention is there to extend the usage of this structure at a specific location, an investigation on fatigue degradation of the structure is an essential factor that has to be carried out before taking any decision. Fatigue is the process of damage accumulation in material due to stress fluctuation caused by variation of loads in service time. The fatigue failure occurs when accumulated damage has exceeded a critical level. In this paper, the remaining fatigue capacity of the jack-up structure is considered as an indicator for adequate use of the structure. It can be specified based on the difference between design-fatigue and fatigue experienced by the structure. The design-fatigue can be determined based on fluctuation of loads during the lifetime of the structure and experienced fatigue is specified by the load conditions, which the structure has experienced during its service time. When the information on the load conditions which the structure has experienced in its service time is available or known precisely, determination of the remaining fatigue capacity could be carried out by using the Palmgren–Miner’s rule. In practice, uncertainties are present in loads and characteristics of material. Hence it will be reasonable to determine the remaining fatigue reliability of the structure by the reliability methods. In this paper, based on a crack propagation approach and achieved information from inspection, it is shown that the remaining fatigue reliability of jack-up structures could be determined and updated by using a Bayesian procedure in the duration of the service time.


1986 ◽  
Vol 23 (1) ◽  
pp. 256-260 ◽  
Author(s):  
Robert D. Foley

We present some non-stationary infinite-server queueing systems with stationary Poisson departure processes. In Foley (1982), it was shown that the departure process from the Mt/Gt/∞ queue was a Poisson process, possibly non-stationary. The Mt/Gt/∞ queue is an infinite-server queue with a stationary or non-stationary Poisson arrival process and a general server in which the service time of a customer may depend upon the customer's arrival time. Mirasol (1963) pointed out that the departure process from the M/G/∞ queue is a stationary Poisson process. The question arose whether there are any other Mt/Gt/∞ queueing systems with stationary Poisson departure processes. For example, if the arrival rate is periodic, is it possible to select the service-time distribution functions to fluctuate in order to compensate for the fluctuations of the arrival rate? In this situation and in more general situations, it is possible to select the server such that the system yields a stationary Poisson departure process.


2021 ◽  
pp. 201-237
Author(s):  
Achyutha Krishnamoorthy ◽  
Dhanya Shajin ◽  
Viswanath C. Narayanan
Keyword(s):  

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Mohamed Boualem ◽  
Natalia Djellab ◽  
Djamil Aïssani

This paper focuses on stochastic comparison of the Markov chains to derive some qualitative approximations for anM/G/1retrial queue with a Bernoulli feedback. The main objective is to use stochastic ordering techniques to establish various monotonicity results with respect to arrival rates, service time distributions, and retrial parameters.


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