SU1099316A1 - Device for simulating queueing systems - Google Patents

Abstract

1. DEVICE FOR SIMULATING OF MASS SERVICE SYSTEMS, containing the first service channel of the application, consisting of a reversible counter, the discharge outputs of which are connected respectively to the inputs of the first AND element and the first OR element, the output of which is connected to the start input of the service unit, the second AND element , a registration unit, characterized in that, with an extension chain of functional capabilities: by simulating a departure from a service channel with a given probability, it additionally contains a switch op pulse, the second service channel of the order, consisting of a series-connected reversing counter, an OR element and a service unit, and a situation analysis unit consisting of a pulse generator, a random pulse generator, a shift register, an AND element, two OR elements, two elements delays, groups of elements And, the output of the pulse generator is connected to the shift input of the shift register and the input of the first delay element, the discharge outputs of the reversible counter are connected respectively to the inputs of the first element and OR, the output of which is connected to the input of a random pulse generator, the output of which is connected to the subtractive output of the reversible counter and the input of the second delay element, the output of which is connected to the first input of the AND element, the second input of which is connected to the output of the second OR element, bit outputs of the shift register connected, respectively, to the first inputs of elements AND groups, the second input of the first element AND groups connected to the output of the third element AND groups, the second inputs of the K-th and (K + D-ro elements, the groups are combined and yens with &} output (K + 3) -th element AND group (, P-1), the second inputs of the n-th and (P + 1) -th elements And group are connected to the output of the random generator, the second input The (P + 2) element of the AND group is connected to the output of the first delay element, the CO inputs of the second element OR are connected; o: they are with the corresponding outputs of the AND elements of the group, the bit inputs of the S shift register signal are connected to the outputs of the corresponding cell elements AND group, the output element And the situation analysis unit is connected to the first information input of the switch impulse in the first subtractive input of the reversing counter, the second subtractive input of which is connected to the first output of the first service channel interception unit and the first input of the registration unit, the second input of which is connected to the output of the last element And group of the situation analysis unit, third

Description

By the subtracting input of the reversible counter and the first summing input of the reversing counter of the second service channel, the second summing input of which is connected to the output of the second element AND of the device, the output of the service unit of the second service channel is connected to the second information input of the pulse switch, the third information input of which is the device input, the first output the pulse switch is connected to the summing input of the reversing counter of the first service channel and the first platoon of the service unit neither the first service channel, the second output of which is connected to the summing input of the reversible counter and the input of the first bit of the shift register of the situation analysis unit, the second output of the pulse switch connected to the first input of the second element I, the second input of which is connected to the control input of the pulse switch and the output of the first element I.

2. The device according to claim 1, characterized in that the service unit comprises a pulse generator, a random pulse generator, a shift register, a group of AND elements, an OR element, an AND element, two delay elements, an oscillator output for them, pulses connected to the front input

the delay element and the shift input of the shift register, the information input of the first bit of the shift register is the first input of the block, the second input of which is the input of the random pulse generator, the output of which is connected to the input of the second delay element whose output is connected to the first input of the And element, the second the input of which is connected to the output of the OR element, the output of the AND element is the first output of the block, the second output of which is the output of the last AND element of the group, the inputs of the OR element are connected to the outputs of the corresponding elements of the group, the first. Inputs are connected to the bit outputs of the shift register, the blanking inputs of the signal of each bit of the shift register are connected to the outputs of the corresponding element AND of the group, the second input of the first element And of the group is connected to the output of the third element I. And the second inputs K-th and () -th element AND group are combined and connected to the output of (K + 3) -th element AND group (, P-1), the second input of the last element And group connected to the output of the first delay element, and the output of the random generator pulses connected to watts the first inputs of the i1 st and (n-1) th elements of the troupe.

The invention relates to computing, is intended to simulate the formation and control of queues and can be used in the study of complex systems.

A device for simulating a queue is known comprising a generator of a quotation, a unit of servicing the quotation, a shift register, and a reversible counter l.

The disadvantage of this device is the impossibility of modeling systems with a queue in which the application would not leave it until it is serviced.

The closest in technical essence and the achieved result to the proposed is a device for simulating a queue containing

A reversive counter, the first group of outputs of which is connected to the corresponding inputs of the queue length simulation unit, the second group of outputs with the corresponding inputs of the set queue limiter, the output of which is connected to the first input of the queue overflow detection unit, the output of which is connected to the first input of the second obeluzhan channel. This device is designed to simulate a queuing system (QS) with a variable queue length of 2j. However, in case of overflow, the queues for applications are rejected and are not considered further. In real SMOs, for example, in large stores, at cash desks at railway stations, etc., situations are possible when a denied service customer assesses the created situation and most likely remains in the previous QS and with a accuracy of 1- (J It is extremely difficult to simulate such situations in an analytical study of complex QS systems. It is most convenient to simulate such situations in the QS using the proposed device. The purpose of the invention is to expand the functionality of the device by simulating the ear. and a request from a service channel with a predetermined probability. The goal is achieved by the fact that a device for simulating a queuing system, containing the first service channel of the application, consisting of a reverse counter, whose bit outputs are connected respectively to the inputs of the first element AND the first element OR, the output of which is connected to the start-up input of the service unit, the second element AND, the registration unit, are introduced a pulse switch, the second service channel of the request consisting of a unified reversible counter, a SHS element and a service unit, and a situation analysis unit consisting of a pulse generator, random pulse generator, shift register, element AND, two OR elements, two delay elements, group of elements AND, the output of the pulse generator is connected to the shift input of the register shift and the input of the first delay element, p; the output outputs of the reversible counter are connected respectively to the inputs of the first OR element, the output of which is connected to the input of a random pulse generator, the output of which oedinen a subtractor vyho house down counter and the input of the second delay element whose output is connected to the first input of the AND, the second input of which is connected to the output 164 of the second elements. This OR, bit outputs of the shift register are connected respectively to the first inputs of elements AND of a group, the second input of the first element AND of a group is connected to the output of the third element AND of a group, the second inputs of the K-th and (K + 1) -th elements of the group are combined and connected to output (K + 3) -th element And group (, n-1), the second inputs and (M + 1) -th element And group connected to the output of the random pulse generator, the second input (f} + 2) -ro element And group connected to the output of the first delay element, the inputs of the second element OR are connected to the corresponding outputs elem The groups AND, bit inputs of the shift register signal are connected to the outputs of the corresponding elements AND groups, the output of the situation analysis block AND element is connected to the first information input of the pulse switch and the first subtractive input of the reversible counter, the second subtractive input of which is connected to the first output of the first service block service channel and the first input of the registration unit, the second input of which is connected to the output of the last element AND of the group of the situation analysis block by the third subtractive input The reversible counter one and the first summing input of the reversible counter of the second service channel, the second summing input of which is connected to the output of the second element AND device, the output of the service unit of the second service channel is connected to the second information input of the pulse switch, the third information input of which is the device input, the first input the pulse switch is connected to the summing input of the reversing counter of the first service channel and the first input of the service unit: The service analog, the second output of which is connected to the summing input of the reversible counter by the input of the first bit of the situation analysis shift register, the second output of the pulse switch is connected to the first input of the second element AND, the second input of which is connected to the control switch of the pulse switch and the output of the first element I. The service unit contains a pulse generator, a random pulse generator, a shift register, a group of AND elements, an OR element, an AND element, two delay elements, the output of a pulse generator, with the input of the first delay element and the shift input of the shift register, the information input of the pair discharge register. The shift is the first input of the block, the second input of which is from the generator input of the random pulse whose output is connected to the input of the second delay element whose output is connected to the first input of the AND element, the second input of which is connected to the output of the OR element, the output of the AND element is the first output of the block, the second output of which is the code of the last AND element of the group, the inputs of the OR element The inputs to the corresponding elements of the AND group, the first inputs of which are connected to the bit outputs of the register, the shift, the blanking inputs of the signal of each register bit, are connected to the outputs of the corresponding AND group, the second input of the first AND element of the group is connected to the output of the third element And the groups, the second inputs of the K-th and (K + 1) -th elements And the groups are combined and connected to the output of (K + 3) -th element And group (, D-1), the second input of the last element And group is connected to the output the first delay element, and the generator output case pulses connected to the second inputs Vi-ro and (n + 1) -th elements of the And group. FIG. 1 shows a block diagram of the device; in fig. 2 is a pulse switch circuit; in fig. 3 is a service block diagram; 4 is a diagram of a situation analysis block. The device contains a reversible counter 1, block, 2 situation analysis, the element OR 3, the switch 4 pulses, the first element AND 5, the unit 6 maintenance, the second element And 7, block 8 registration, the input 9 of the device. The switch 4 pulses contains elements OR 10-12, elements AND 13-1 delay elements 17-19, prohibition element 20, inputs 21-23, outputs 24 and 25.. Service unit 6 contains the first 2-6 and second 27 delay elements, AND 28, OR element 29, AND 30 group, pulse generator 31, random pulse generator 32, shift register 33, outputs 34 and 35. Situation analysis block 2 contains the outputs 36 and 37, the second element OR 38, the element AND 39, the first element OR 40, the first 41 and the second 42 delay elements - reversible counter 43, pulse generator 44, random pulse generator 45, shift register 46, AND 47 group of elements. The device works as follows. At input 9, impulses imitating the flow of the flow are received. If there is no queue defined in the first service channel, the signal on receipt of application from output 25 goes to the summing input of the reversible counter 1 and to the first input of service unit 6, where it is used as an auxiliary signal by this input. If there is a queue of a certain length, the applications from counter 4 are received from output 24 to the first input of the second element AND 7 Entering inputs to switch 4 (Fig. 2) applications (input 9 is the input stream, input 21 is from the second service channel, input 22 - from the output of the situation analysis block) first get to the element OR 11. The block provides a device that does not allow for loss of quotes if they arrive at two or three inputs simultaneously. If the applications pass simultaneously through two of the three inputs, then along with the signal recorded through the element OR 11, the signal is also fixed by one of the elements AND 14-16 and through the element OR 12 and the delay element 19 the second signal goes to one from exits. Thus, in the reversible counter 1, the arrival of two applications is recorded. If the applications are received simultaneously through three inputs 9, 21 and 22, then the receipt of three applications is recorded: the first through the element OR 11, the second through one of the elements 14-16, the element OR 12 and the delay element 19, the third through element And 13 and elements 17 and 18 of the delay. The requests go out of switch 4 or through prohibition element 20 in the absence of a queue of a certain length, or directly from the output of the element OR 10 in the presence of a queue. In the latter case, the control input of the prohibition element 20 is given a signal from the output of the queue limit setter (element 5), which fixes a certain length of the queue on. reversible counter 1. When element 5 is triggered, the signal from its output enters the input of prohibition element 2 for switching outputs by a switch A and simultaneously is fed to the first input of element i. 7, preparing it for opening. In this case, the applications from the output 24 of the switch 4 arrive at the second input of the element I 7 and further from its output at the first input of the second service channel. In the second service channel, built similarly to the first application, the service is performed. Unserviceable for some reason, the second channel returns to the first channel via input 21 of switch 4. If the queue fixed in the reversible counter 1 is less than the set limit value, element 7 is closed, and element 20 is opened and applications come in output 25. The presence of a queue is detected by the element OR 3 (Fig. 3). If there was a hot ticket in the center, then the signal from the output of the IL-3 element is fed to the service unit 6, where the generator 32 is turned on, simulating a random service time for the application. While at the output of the element OR 3 there is a signal, generator 32 is on. The time between random pulses from generator 32 is taken during the service of an ordinary application. In addition to the generator 32, which simulates the service time of the application, the main elements of the service unit 6 are also the clock pulse generator (GTI) 31, URS, and the element OR 29. The GTI and URS are used for storing for the time ttgf, the service received in block 6 Vani. This time is set by advancing the auxiliary signal on the URS by the shear pulses from the GTI arriving at the Q input of the register 33. The auxiliary signal to the URS of the block 6 comes from the output 25 of the switch 4. If during the time from the generator 32, the service completion signal is received application, it is considered served and a signal about this passes at the output 35 of the service unit 6. The time sd is determined by the register 33 and the frequency of the clock pulses of the GTI 31. To ensure the passage of the service request signal to the output 35 of block 6 from the generator 32 output, a pulse is received in the URS, which is used to selectively turn off the auxiliary signal from the output 25 switch and promoted by urs. Suppression of the auxiliary signal in the URS is as follows. If in the single state there is also a - and bit of register 33, then at the first input of the corresponding element AND of group 30 there is a resolving potential from the output of this discharge. Then, when a pulse appears from the generator 32 at the second input of this element AND it passes to the zero input h then register bit 33 and through the element OR 29 to the first input of the element AND 28. The second input of the element AND 28 receives the same pulse from the generator 32 through the delay element 27. If at the time of the occurrence of the signal from the generator 32, the bit of the register 33 is in the zero state, then the enabling signal is at the inverse output of this bit and the pulse from the generator 32 passes to the corresponding two elements AND of group 30 (g | -1) - th bit If the (I-1) th register bit of 33 is in a single state, then it will zero. Otherwise, the signal from generator 32 is transmitted to the next (P-2) -th bit, i.e. the search for the nearest register bit 33 with a single state continues. From the output 35 of the service unit 6, a signal about the end of the service for less than or equal time is fed to the subtractive input of the reversible counter 1 for removal of the meter from the service system and to the summing input of the reversible counter of the registration unit 8. If, during the time in Ndd, the pulse is not received from the generator 32 in the URS, then the application is considered not served. In this case, the denial of service signal comes from

output rt-th bit URS through the corresponding element And group 30 to the input of block 6 and further to the input of block 2 of the situation analysis.

Unserved in block 6 of the application in block 2 analyzes the situation (Fig. 4). As a result of the analysis, the application may with some probability go to the second service channel - output 36 of block 2. The second possibility of the application is that it returns with probability 1-sec to the previous service channel through switch 4 via input 37. In both cases, the unsuccessful application leaving block 2 is deregistered from this channel by deducting the inputs of the reversible counter 1. When the application leaves this service channel, leaving the other channel, a signal is sent to the subtracting input of the reversible counter of unit 8, fix This is the best way to keep this service out of service. .

The operation of the situation analysis unit 2 is similar to the operation of the maintenance unit 6. Incoming on input 34 optional

assessment

produces

for

service situation at the time ts ..,. ,, which is defined as., determined by the size of the register 46

and the frequency of the generator 44 block 2 (Fig. 4). The application turns on the random pulse generator 45 using a reversible counter 43 and the element OR 40. The generator 45 is turned on while at least two applications are in block 2. The generator 45 simulates the random decision time of the application. If 3at.g is the advance time of the auxiliary signal on the URS of the unit 2, a signal is received from the generator 45. That application passes through elements 38 and 39 to input 37 of block 4. In this case, the application remains in the same service channel. In this case, the selective suppression of the auxiliary signal in the URS of block 2 occurs in the same way as in block 6 of the service.

If during time C, the generator 45 does not receive a signal, it is considered.

That for the decision made to leave this channel in the second channel. Technically, this is due to the fact that the generator 45 did not receive a selective blanking signal from generator 45 for a time t ... j. Consequently,

L,

the signal from the nth output of register 46 is fed to output 36 of block 2 and to the second service channel. The same signal is also fed to the readout input of the reversible counter of block 8, where it is recorded as certain losses for a given service channel. As a result, in block 8 of registration, the result of the effectiveness of this channel is determined. Similarly, the efficiency of the second channel is determined by connecting the pulse counter to input 9, it is possible to determine the number of applications N received in the service system. Then the block of registration of the first channel gives the number of applications N served by the first channel, and the block of results of the second channel gives the number of applications C) serviced by it. If we denote the number of applications that did not receive service by the time t and are in queues of service channels or in the state of assessment of the situation through Nj, then it will be

N N -,

Thereby, it is possible to calculate the probability characteristics of a given service system.

Technically, the second service channel is made exactly the same as the first. To give it properties with other characteristics, it is enough to change the width of the URS or the frequency of the GTI.

Thus, the proposed device provides the opportunity. CMC modeling is close to real and can be used to optimize the performance of complex expensive systems where it is difficult or impossible to solve this problem analytically.

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Claims (2)

1. DEVICE FOR MODELING MASS SERVICE SYSTEMS, 'containing the first channel for servicing applications, consisting of a reverse counter, the bit outputs of which are connected respectively to the inputs of the first element And and the first element OR, the output of which is connected to the input of the start of the service unit, the second element And, block registration, characterized in that, in order to. expand the functionality by means of modeling the withdrawal of applications from the service channel -> service with a given probability, it additionally contains a switch and pulses, a second application service channel composed of sequentially joined-down counter, and maintenance of the OR block and the block situation analysis coc ·? consisting of a pulse generator, a random pulse generator, a shift register, an AND element, two OR elements, two delay elements, a group of AND elements, the output of the pulse generator is connected to the shift input of the shift register and the input of the first delay element, the discharge outputs of the reverse counter are connected respectively to the inputs the first OR element, the output of which is connected to the input of the random pulse generator, the output of which is connected to the subtracting output of the reverse counter and the input of the second delay element, the output to It is connected to the first input of the AND element, the second input of which is connected to the output of the second OR element, the bit outputs of the shift register are connected respectively to the first inputs of the AND elements of the group, the second input of the first AND element is connected to the output of the third AND element, the second inputs of and (K + 1) th elements. § the groups are combined and connected to the output of the (K + 3) th element of the And group (K = 2, 1) -1), the second inputs of the ηth and (P + 1) th elements of the And group are connected to the output of the case generator g pulses, the second input of the (П + 2) ~ th AND element of the group is connected to the output of the first delay element, the inputs of the second OR element are connected to the corresponding outputs of the And elements of the group, the discharge inputs of the blanking of the shift register signal are connected to the outputs of the corresponding 'And elements, the output of the AND element of the situation analysis unit is connected to the first information input of the switch and pulses to the first subtracting input of the reverse counter, the second subtracting input of which is connected to the first output of the service unit of the first service channel and the first input of the registration unit, the second input of which is connected to the output of the last element AND of the group of the situation analysis unit, the third subtracting input of the reverse the counter and the first summing input of the reverse counter of the second service channel, the second summing input of which is connected to the output of the second element AND device, the output of the maintenance unit W The first service channel is connected to the second information input of the pulse switch, the third information input of which is the device input, the first output of the pulse switch is connected to the summing input of the reverse counter of the first service channel and the first input of the service unit of the first service channel, the second output of which is connected to the summing input of the reverse counter and the input of the first discharge of the shift register of the situation analysis unit, the second output of the pulse switch is connected to the first input the second element And, the second input of which is connected to the control input of the pulse switch and the output of the first element I. 2. The device pop. 1, characterized in that the service unit comprises a pulse generator, a random pulse generator, a shift register, a group of AND elements, an OR element, an AND element, two delay elements, the output of the pulse generator is connected to the input of the first delay element and the shift input of the shift register, information the input of the first category of the shift register is the first input of the block, the second input of which is the input of the random pulse generator, the output of which is connected to the input of the second delay element, the output of which is connected to the first the AND element, the second input of which is connected to the output of the OR element, the output of the AND element is the first output of the block, the second output of which is the output of the last AND element, the inputs of the OR element (connected to the outputs of the corresponding AND elements, the first inputs of which are connected to the bit the outputs of the shift register, the signal blanking inputs of each bit of the shift register are connected to the outputs of the corresponding element of the AND group, the second input of the first element of the AND group is connected to the output of the third element of the I. group, the second inputs D of the Kth and (K + 1) -th element of the And group are combined and connected to the output of the (K + 3) -th element of the And group (K = 2, P-1), the second input of the last element of the And group is connected to the output of the first delay element, and the output of the random pulse generator is connected to the second inputs of the Pth and (P + 1) -th elements of the ^u group. f ί