Response times in M/M/1 time-sharing schemes with limited number of service positions

1988 ◽  
Vol 25 (3) ◽  
pp. 579-595 ◽  
Author(s):  
Benjamin Avi-Itzhak ◽  
Shlomo Halfin
Keyword(s):  
Response Time ◽  
Response Times ◽  
Laplace Transforms ◽  
Time Sharing ◽  
Time Variance ◽  
Waiting Line ◽  
Time Sharing System

Two service schemes for an M/M/1 time-sharing system with a limited number of service positions are studied. Both schemes possess the equilibrium properties of symmetric queues; however, in the first one, a preempted job is placed at the end of the waiting line; while in the second one, it is placed at the head of the line. Methods for calculating the Laplace transforms and moments of the response times are presented. The variances of the response times are then compared numerically to indicate that the first scheme is superior to the second scheme. It is also indicated that in both cases the response time variance decreases when the number of service positions increases.

Response times in M/M/1 time-sharing schemes with limited number of service positions

1988 ◽  
Vol 25 (03) ◽  
pp. 579-595 ◽  
Author(s):  
Benjamin Avi-Itzhak ◽  
Shlomo Halfin
Keyword(s):  
Response Time ◽  
Response Times ◽  
Laplace Transforms ◽  
Time Sharing ◽  
Time Variance ◽  
Waiting Line ◽  
Time Sharing System

Two service schemes for an M/M/1 time-sharing system with a limited number of service positions are studied. Both schemes possess the equilibrium properties of symmetric queues; however, in the first one, a preempted job is placed at the end of the waiting line; while in the second one, it is placed at the head of the line. Methods for calculating the Laplace transforms and moments of the response times are presented. The variances of the response times are then compared numerically to indicate that the first scheme is superior to the second scheme. It is also indicated that in both cases the response time variance decreases when the number of service positions increases.

On the Psychological Importance of Time in a Time Sharing System

1968 ◽  
Vol 10 (2) ◽  
pp. 135-142 ◽  
Author(s):  
Jaime R. Carbonell ◽  
Jerome I. Elkind ◽  
Raymond S. Nickerson
Keyword(s):  
Response Time ◽  
Response Times ◽  
Time Sharing ◽  
Single Measure ◽  
Dynamical Characteristics ◽  
Concurrent Tasks ◽  
Different Types ◽  
On Line ◽  
The Individual ◽  
Time Sharing System

One of the most important problems in the design and/or operation of a computer utility is to obtain dynamical characteristics that are acceptable and convenient to the on-line user. This paper is concerned with the problems of access to the computer utility, response time and its effect upon conversational use of the computer, and the effects of load on the system. Primary attention is placed upon response time; rather than a single measure, a set of response times should be measured in a given computer utility, in correspondence to the different types of operations requested. It is assumed that the psychological value of short response time stems from a subjective cost measure of the user's own time, largely influenced by the value of concurrent tasks being postponed. A measure of cost (to the individual and/or his organization) of the time-on-line required to perform a task might thus be derived. More subtle is the problem of the user's acceptability of given response times. This acceptability is a function of the service requested (e.g., length of computation), and variability with respect to expectations due both to uncertainty in the user's estimation and to variations in the response time originated by variable loads on the system. An effort should be made by computer-utility designers to include dynamic characteristics (such as prediction of loads and their effects) among their design specifications.

Server sharing with a limited number of service positions and symmetric queues

1987 ◽  
Vol 24 (04) ◽  
pp. 990-1000 ◽  
Author(s):  
Benjamin Avi-Itzhak ◽  
Shlomo Halfin
Keyword(s):  
Finite Number ◽  
Generating Functions ◽  
Delay Time ◽  
Time Distribution ◽  
Equilibrium Distribution ◽  
Laplace Transforms ◽  
Processor Sharing ◽  
Time Sharing ◽  
Time Variance ◽  
Special Case

A class of M/G/1 time-sharing queues with a finite number of service positions and unlimited waiting space is described. The equilibrium distribution of symmetric queues belonging to this class is invariant under arbitrary service-independent reordering of the customers at instants of arrivals and departures. The delay time distribution, in the special case of one service position where preempted customers join the end of the line, is provided in terms of Laplace transforms and generating functions. It is shown that placing preempted customers at the end of the line rather than at the beginning of the line results in a reduction of the delay time variance. Comparisons with the delay time variance of the case of unlimited number of service positions (processor sharing system) are presented.

Server sharing with a limited number of service positions and symmetric queues

1987 ◽  
Vol 24 (4) ◽  
pp. 990-1000 ◽  
Author(s):  
Benjamin Avi-Itzhak ◽  
Shlomo Halfin
Keyword(s):  
Finite Number ◽  
Generating Functions ◽  
Delay Time ◽  
Time Distribution ◽  
Equilibrium Distribution ◽  
Laplace Transforms ◽  
Processor Sharing ◽  
Time Sharing ◽  
Time Variance ◽  
Special Case

A class of M/G/1 time-sharing queues with a finite number of service positions and unlimited waiting space is described. The equilibrium distribution of symmetric queues belonging to this class is invariant under arbitrary service-independent reordering of the customers at instants of arrivals and departures. The delay time distribution, in the special case of one service position where preempted customers join the end of the line, is provided in terms of Laplace transforms and generating functions. It is shown that placing preempted customers at the end of the line rather than at the beginning of the line results in a reduction of the delay time variance. Comparisons with the delay time variance of the case of unlimited number of service positions (processor sharing system) are presented.

PENGENALAN HARDWARE KOMPUTER

2020 ◽  
Author(s):  
Adel Syah Pohan
Keyword(s):  
Computer Hardware ◽  
Time Sharing ◽  
Time Sharing System

Sejarah jaringan komputer bermula dari lahirnya konsep jaringan komputer pada tahun 1940-an di Amerika yang digagas oleh sebuah proyek pengembangan komputer MODEL I di laboratorium Bell dan group riset Universitas Harvard yang dipimpin profesor Howard Aiken. Kemudian pada tahun 1950-an ketika jenis komputer mulai berkembang sampai terciptanya super komputer, maka sebuah komputer harus melayani beberapa tempat yang tersedia (terminal), untuk itu ditemukan konsep distribusi proses berdasarkan waktu yang dikenal dengan nama TSS (Time Sharing System). Maka untuk pertama kalinya bentuk jaringan (network) komputer diaplikasikan. Hardware adalah perangkat keras computer yang nampak secara fisik dan dapat di raba. Berdasarkan sifat dan kegunaannya perangkat keras computer (hardware computer) dapat dikelompokan menjadi 4 bagian : Perangkat input, Perangkat keluaran, Perangkat proses, Perangkat penyimpanan. Perangkat keras komputer adalah semua bagian fisikkomputer, dibedakan dengan data yang berada di dalamnya atau yang beroperasi di dalamny sedangkan perangkat lunak merupakan perangkat yang dapat dilihat namun tidak dapat disentuh secara langsung oleh manusia, perangkat lunak yang menyediakan instruksi buat perangkat keras untuk menyelesaikantugasnya.

An experimental time-sharing system

1962 ◽  
Author(s):  
Fernando J. Corbató ◽  
Marjorie Merwin-Daggett ◽  
Robert C. Daley
Keyword(s):  
Time Sharing ◽  
Experimental Time ◽  
Time Sharing System

Design considerations for an educational time-sharing system

1969 ◽  
Author(s):  
Robert F. Hargraves ◽  
Andrew G. Stephenson
Keyword(s):  
Time Sharing ◽  
Design Considerations ◽  
Time Sharing System

scholarly journals Stimulus-response time to invasive blood pressure alarms: implications for the safety of critical-care patients

2014 ◽  
Vol 35 (2) ◽  
pp. 135-141 ◽  
Author(s):  
Adele Kuckartz Pergher ◽  
Roberto Carlos Lyra da Silva
Keyword(s):  
Blood Pressure ◽  
Response Time ◽  
Response Times ◽  
Hemodynamic Instability ◽  
Military Hospital ◽  
Invasive Blood Pressure ◽  
Stimulus Response ◽  
The City ◽  
Physical Layout

Observational, descriptive, exploratory, case study with the objective of measuring the stimulus-response time of the team to alarms monitoring invasive blood pressure (IBP) and analyzing the implications of this time for the safety of the patient. From January to March 2013, 60 hours of structured observation were conducted with registration of the alarms activated by IBP monitors in an adult ICU at a military hospital in the city of Rio de Janeiro. 76 IBP alarms were recorded (1.26 alarms/hour), 21 of which (28%) were attended to and 55 (72%) considered as fatigued. The average response time to the alarms was 2 min. 45 sec. The deficit in human resource and physical layout were factors determining the delay in response to the alarms. The increase in response times to these alarms may compromise the safety of patients with hemodynamic instability, especially in situations such as shock and the use of vasoactive drugs.

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