scholarly journals Performance Evaluation of the Priority Multi-Server System MMAP/PH/M/N Using Machine Learning Methods

Mathematics ◽  
2021 ◽  
Vol 9 (24) ◽  
pp. 3236
Author(s):  
Vladimir Vishnevsky ◽  
Valentina Klimenok ◽  
Alexander Sokolov ◽  
Andrey Larionov
Keyword(s):  
Machine Learning ◽  
High Efficiency ◽  
Performance Characteristics ◽  
New Method ◽  
Arrival Process ◽  
Priority Systems ◽  
Loss Probabilities ◽  
Number Of Customers ◽  
Multi Server ◽  
Stationary Probabilities

In this paper, we present the results of a study of a priority multi-server queuing system with heterogeneous customers arriving according to a marked Markovian arrival process (MMAP), phase-type service times (PH), and a queue with finite capacity. Priority traffic classes differ in PH distributions of the service time and the probability of joining the queue, which depends on the current length of the queue. If the queue is full, the customer does not enter the system. An analytical model has been developed and studied for a particular case of a queueing system with two priority classes. We present an algorithm for calculating stationary probabilities of the system state, loss probabilities, the average number of customers in the queue, and other performance characteristics for this particular case. For the general case with K priority classes, a new method for assessing the performance characteristics of complex priority systems has been developed, based on a combination of machine learning and simulation methods. We demonstrate the high efficiency of the new method by providing numerical examples.

On the identification of Poisson arrivals in queues with coinciding time-stationary and customer-stationary state distributions

1983 ◽  
Vol 20 (04) ◽  
pp. 860-871 ◽  
Author(s):  
Dieter König ◽  
Masakiyo Miyazawa ◽  
Volker Schmidt
Keyword(s):  
Stationary State ◽  
Queueing Systems ◽  
Sufficient Conditions ◽  
Arrival Process ◽  
Loss Probabilities ◽  
Poisson Arrivals ◽  
Number Of Customers

For several queueing systems, sufficient conditions are given ensuring that from the coincidence of some time-stationary and customer-stationary characteristics of the number of customers in the system such as idle or loss probabilities it follows that the arrival process is Poisson.

scholarly journals Analysis of retrial queue with heterogeneous servers and Markovian arrival process

Informatics ◽  
2020 ◽  
Vol 17 (1) ◽  
pp. 29-38
Author(s):  
Mei Liu
Keyword(s):  
Retrial Queue ◽  
Markovian Arrival Process ◽  
Arrival Process ◽  
Service Rate ◽  
Heterogeneous Servers ◽  
Retrial Queueing System ◽  
Retrial Queueing ◽  
System Effectiveness ◽  
Multi Server ◽  
Stationary Probabilities

Multi-server retrial queueing system with heterogeneous servers is analyzed. Requests arrive to the system according to the Markovian arrival process. Arriving primary requests and requests retrying from orbit occupy an available server with the highest service rate, if there is any available server. Otherwise, the requests move to the orbit having an infinite capacity. The total retrial rate infinitely increases when the number of requests in orbit increases. Service periods have exponential distribution. Behavior of the system is described by multi-dimensional continuous-time Markov chain which belongs to the class of asymptotically quasi-toeplitz Markov chains. This allows to derive simple and transparent ergodicity condition and compute the stationary probabilities distribution of chain states. Presented numerical results illustrate the dynamics of some system effectiveness indicators and the importance of considering of correlation in the requests arrival process.

On the identification of Poisson arrivals in queues with coinciding time-stationary and customer-stationary state distributions

1983 ◽  
Vol 20 (4) ◽  
pp. 860-871 ◽  
Author(s):  
Dieter König ◽  
Masakiyo Miyazawa ◽  
Volker Schmidt
Keyword(s):  
Stationary State ◽  
Queueing Systems ◽  
Sufficient Conditions ◽  
Arrival Process ◽  
Loss Probabilities ◽  
Poisson Arrivals ◽  
Number Of Customers

For several queueing systems, sufficient conditions are given ensuring that from the coincidence of some time-stationary and customer-stationary characteristics of the number of customers in the system such as idle or loss probabilities it follows that the arrival process is Poisson.

On a Markovian queue with weakly correlated interarrival times

1981 ◽  
Vol 18 (01) ◽  
pp. 190-203 ◽  
Author(s):  
Guy Latouche
Keyword(s):  
Time Distribution ◽  
Queueing System ◽  
Interarrival Time ◽  
Probability Vector ◽  
Common Value ◽  
Markovian Queue ◽  
The Stability ◽  
Number Of Customers ◽  
Stationary Probabilities ◽  
Stationary Probability Vector

A queueing system with exponential service and correlated arrivals is analysed. Each interarrival time is exponentially distributed. The parameter of the interarrival time distribution depends on the parameter for the preceding arrival, according to a Markov chain. The parameters of the interarrival time distributions are chosen to be equal to a common value plus a factor ofε, where ε is a small number. Successive arrivals are then weakly correlated. The stability condition is found and it is shown that the system has a stationary probability vector of matrix-geometric form. Furthermore, it is shown that the stationary probabilities for the number of customers in the system, are analytic functions ofε, for sufficiently smallε, and depend more on the variability in the interarrival time distribution, than on the correlations.

scholarly journals Improved Specificity of a New Homogeneous Assay for LDL-Cholesterol in Serum with Abnormal Lipoproteins

2006 ◽  
Vol 52 (5) ◽  
pp. 886-888 ◽  
Author(s):  
Yasumasa Iwasaki ◽  
Hiroyuki Matsuyama ◽  
Nobuo Nakashima
Keyword(s):  
Clinical Practice ◽  
Obstructive Jaundice ◽  
Ldl Cholesterol ◽  
Performance Characteristics ◽  
New Method ◽  
Assay Performance ◽  
Basic Performance ◽  
Homogeneous Method ◽  
Homogeneous Assay ◽  
Improved Performance

Abstract Background: Although a homogeneous assay for serum LDL-cholesterol (LDL-C) has become a routine clinical procedure, problems remain in assay performance characteristics. Methods: We examined the performance of a recently developed automated homogeneous assay (New-Daiichi assay) for serum LDL-C and compared the results with those obtained by the current homogeneous method (Denka-Seiken assay) or by ultracentrifugation as a control. Results: The New-Daiichi assay showed satisfactory basic performance characteristics such as reproducibility, linearity, and stability. There was no interference in the assay by various substances examined. The LDL-C values obtained with this method correlated well with those obtained by ultracentrifugation. In samples from patients with obstructive jaundice, both methods detected cholesterol from abnormal lipoproteins (such as lipoprotein-X and -Y), but the New-Daiichi assay was less reactive and more specific for LDL-C. Conclusion: The new method has improved performance for the accurate measurement of LDL-C in clinical practice.

Machine learning: The trends of developing high-efficiency single-atom materials

2021 ◽  
Vol 1 (1) ◽  
pp. 24-26
Author(s):  
Jiarui Yang ◽  
Wen-Hao Li ◽  
Dingsheng Wang
Keyword(s):  
Machine Learning ◽  
High Efficiency ◽  
Single Atom

scholarly journals Optimization of C-to-G base editors with sequence context preference predictable by machine learning methods

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tanglong Yuan ◽  
Nana Yan ◽  
Tianyi Fei ◽  
Jitan Zheng ◽  
Juan Meng ◽  
...  
Keyword(s):  
Machine Learning ◽  
High Efficiency ◽  
Codon Optimization ◽  
Sequence Context ◽  
Learning Methods ◽  
Specific Sequence ◽  
Uracil Dna Glycosylase ◽  
Base Editing ◽  
Machine Learning Methods ◽  
Deep Learning Model

AbstractEfficient and precise base editors (BEs) for C-to-G transversion are highly desirable. However, the sequence context affecting editing outcome largely remains unclear. Here we report engineered C-to-G BEs of high efficiency and fidelity, with the sequence context predictable via machine-learning methods. By changing the species origin and relative position of uracil-DNA glycosylase and deaminase, together with codon optimization, we obtain optimized C-to-G BEs (OPTI-CGBEs) for efficient C-to-G transversion. The motif preference of OPTI-CGBEs for editing 100 endogenous sites is determined in HEK293T cells. Using a sgRNA library comprising 41,388 sequences, we develop a deep-learning model that accurately predicts the OPTI-CGBE editing outcome for targeted sites with specific sequence context. These OPTI-CGBEs are further shown to be capable of efficient base editing in mouse embryos for generating Tyr-edited offspring. Thus, these engineered CGBEs are useful for efficient and precise base editing, with outcome predictable based on sequence context of targeted sites.

Design of high-efficiency Hybrid Power Amplifier with concurrent F&F−1 class operations for 5G application

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Meisam Tahmasbi ◽  
Farhad Razaghian ◽  
Sobhan Roshani
Keyword(s):  
Power Amplifier ◽  
High Efficiency ◽  
New Method ◽  
Power Added Efficiency ◽  
Hybrid Power ◽  
Novel Structure ◽  
Mode A

Abstract This paper presents a novel structure of Hybrid Power Amplifier (HPA) to operate in two arbitrary classes of operation at two desirable frequencies. The proposed HPA is designed in concurrent F&F−1 classes, simultaneously for 5G application. Presented HPA can solve the harmonics interference problem for concurrent F and F−1 classes and also for any arbitrary class of operation in desired frequencies. The designed HPA operates at 1.5 GHz frequency in the F class mode, while operates at 2.1 GHz frequency in the F−1 class mode. A new method is presented by using two diplexers to provide two paths for signal in different frequencies. Two parallel paths are used at the output of the HPA circuit, so the proposed HPA can operate at two classes. Two diplexers are used in the HPA to make proper isolation between the designed paths. In design of the proposed HPA, according to the utilized diplexers, the amplifier can operate between two arbitrary classes of operation at desired frequencies without any specific switch. The measured drain efficiency (DE) and power added efficiency (PAE) parameters are 57 and 51%, respectively at 2.1 GHz, while measured DE and PAE are 64 and 54%, respectively at 1.5 GHz.

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