CSE6010-Assignment 3

Sample code - one pump gas station

events: arrival + departure

arrival -> departure
simulation time: unprocesed events are stored in pending list

simulation

Preview

simulate the operation of a call center that handles both incoming and outgoing telephone calls
two different kinds of agent:
service agent : 700 sales agent: 300

two different kinds of call:

incoming calls :

• service + sales both are able to handle, service first, if not available then sales, then wait in queues(0.25 probability hang up, 0.75 waits until the service)m
• incoming calls are assumed to follow a Poisson distribution, with average arrival rate A per second, time between successive calls is exponentially distributed with a mean value of 1/A.
  *the time for an agent to answer an incoming call is uniformly distributed over the interval [300, 700] seconds

outgoing calls :
*only sales agent can handle. if no sales agents available, abandon the call
*every 60 seconds the dialer system places calls, then take 10 seconds to determine which calls got through, each call that got through is routed to a sales agent

parameters:

*S_TRUE : the probability an outgoing call is successful (success = call + go through)
*S_EST + N_IDLE / S_EST
*S_EST: the estimated probability value of success computed by the simulation program
*N_IDLE: the number of idle sales agents

Simulation engine

*event list managemnt
*managinig advances in simulation time

Simulation application

*state variables
*code modeling system behavior
*I/O and user interface software

event handler procedures
arrival event{...} departure event{...}

define each structure's content.
how to use the struct? first initialize, then call them?

Background Knowledge
Structure

//learning note of struc in c

//structure 
struct flightType
{
	char flightNum[7]; 
	int altitude;
	double airspeed;
};

struct flightType plane; //declare a variable of this new type

struct flightType
{
	char flightNum[7]; 
	int altitude;
	double airspeed;
}plane; //general syntax for a structure declaration 


//access the struct using the dot "." operation
plane.airspeed = 800.00; 
plane.altitude = 10000;


//typedef provide no additional functionality -> give clarity to code
typedef type name; //cause the identifier name to be synonymous with the type 'type'(both basic type of aggregate type is ok)

typedef int Color;
Color pixels[500];

//we can use typedef to create a name for the sturcture we defined 
struct flightType
{
	char flightNum[7]; 
	int altitude;
	double airspeed;
};
typedef struct flightType Flight;
Flight plane;
//equivalent to the declaration in the line14

//allocate contiguous region of memory to each structure
Flight planes[100]; //declare an array of structures

//calculate the average airspeed of 100 planes
int i;
double sum = 0;
double averageAirSpeed;
for (int i = 0; i < 100; i++){
	sum = sum + plane[i].airspeed;
}
averageAirSpeed = sum / 100;
//

// create pointers to structures
Flight *planePtr;
planePtr = &plane[34]; //assign this variable
(*planePtr).longitude //access any of the member fields pointed to by this pointer variable
// equal 
planePtr -> longitude;

Linked List

dynamic allocation
use pointer to

sample code:

Application:
EventHandler: call Arrival() and Departure() Funtion
Arrival() funtion: generate the next arrival() + determine the departure time of the arrival event if the pump is free
Departure() function: schedule the departure time, deal with the atpump type

engine:
Create an Event List: FEL
Remove
PrintList
Schedule function: insert the new event into the event list
RunSim function: to loop before the simulation time get the limit.

Binomial distribution
Generate random number
Summary:
*Application: Event handle procedures
finish three major part:

1. define Event Function
2. define EventHandler Function: to check which type of the event it is
3. define NumberGenerator: to generate the service time and the incoming calling's time

*Engine: Event processing loop
finish the loop:
1.define the datastructure to generate FEL(Future Event List)

什么时候需要排队呢：before the first finished call, the sum_call > sum_servant