ISYE 6644 MIDTERM 2 EXAM
QUESTIONS WITH CORRECT
ANSWERS
Where can you set the buffer size of a certain queue? - Answer-In a Queue block in the
Blocks template
True or False? It's possible to request servers in a set randomly, cyclically, or according
to some priority characteristic (such as the order in which they are placed in the set) -
Answer-True
Arena - Basic Process - Answer-- Create
- Process
- Batch
- Assign
- Dispose
- Decide
- Separate
- Record
- Attribute
- Queue
- Variable
- Set
- Entity
- Resource
- Schedule
Arena - Variables - Answer-Variables are global.
- If you change a variable any place in the Arena program, it gets changed everywhere
How can you change attributes, variables, and other stuff in Arena? - Answer-Assign
module
Attribute spreadsheet - Answer-The attribute spreadsheet keeps track of existing
attributes that you might define in an Assign
Arena Internal Variables - Answer-Arena keeps track of and continuously updates lots
of stuff as the simulation runs.
Example:
- TNOW = current simulated time
, - NR(Barber) = # of resource Barber's servers now working
- NQ(Process 1.Queue) = # customers in that queue
- Create 1.NumberOut = # of customers who have so far left the module named Create
1
Batch Module - Answer-- Combine "batch" multiple customers into one "super"
customers
- Batch Size = 3 accumulates 3 guys before sending off the super-customer
- If you want to eventually to reconstitute the original members, set Type = Temporary
Separate Module - Answer-- Duplicate a single entity, or split multiple entities that had
been combined in a Batch module
- If dealing with a Permanent batch, usually use Duplicate Original to get several
customers all with the same attributes
- If dealing with a Temporary batch, use Split Existing Batch to reproduce customers
with original attributes
Record Module - Answer--Collect statistics when an entity passes through the module
Advanced Process Template - Answer-- Delay
- Release
- Seize
-Expression
-Failure
Failure spreadsheet - Answer-- You can cause resource failures by scheduling
"breakdown" demons" (fake customers with high priority)
- Better way is to use the Resource and Failure spreadsheets in conjunction with each
other
-Can schedule multiple failures by using multiple rows of the Failure column in the
Resource spreadsheet.
Block Template - Answer-- Alter
- Delay
- Queue
- Seize
- Release
Which property is not desirable for a good pseudo-random number generator? -
Answer-We must be able to look up the series of PRNs from a table.
Good pseudo-random number genator
- The numbers must appear to be Unif(0,1)
- The numbers are approximately independent
- We should we able to generate the PRNs very, very quickly
- We can reproduce any sequence of PRNs if called upon to do so
QUESTIONS WITH CORRECT
ANSWERS
Where can you set the buffer size of a certain queue? - Answer-In a Queue block in the
Blocks template
True or False? It's possible to request servers in a set randomly, cyclically, or according
to some priority characteristic (such as the order in which they are placed in the set) -
Answer-True
Arena - Basic Process - Answer-- Create
- Process
- Batch
- Assign
- Dispose
- Decide
- Separate
- Record
- Attribute
- Queue
- Variable
- Set
- Entity
- Resource
- Schedule
Arena - Variables - Answer-Variables are global.
- If you change a variable any place in the Arena program, it gets changed everywhere
How can you change attributes, variables, and other stuff in Arena? - Answer-Assign
module
Attribute spreadsheet - Answer-The attribute spreadsheet keeps track of existing
attributes that you might define in an Assign
Arena Internal Variables - Answer-Arena keeps track of and continuously updates lots
of stuff as the simulation runs.
Example:
- TNOW = current simulated time
, - NR(Barber) = # of resource Barber's servers now working
- NQ(Process 1.Queue) = # customers in that queue
- Create 1.NumberOut = # of customers who have so far left the module named Create
1
Batch Module - Answer-- Combine "batch" multiple customers into one "super"
customers
- Batch Size = 3 accumulates 3 guys before sending off the super-customer
- If you want to eventually to reconstitute the original members, set Type = Temporary
Separate Module - Answer-- Duplicate a single entity, or split multiple entities that had
been combined in a Batch module
- If dealing with a Permanent batch, usually use Duplicate Original to get several
customers all with the same attributes
- If dealing with a Temporary batch, use Split Existing Batch to reproduce customers
with original attributes
Record Module - Answer--Collect statistics when an entity passes through the module
Advanced Process Template - Answer-- Delay
- Release
- Seize
-Expression
-Failure
Failure spreadsheet - Answer-- You can cause resource failures by scheduling
"breakdown" demons" (fake customers with high priority)
- Better way is to use the Resource and Failure spreadsheets in conjunction with each
other
-Can schedule multiple failures by using multiple rows of the Failure column in the
Resource spreadsheet.
Block Template - Answer-- Alter
- Delay
- Queue
- Seize
- Release
Which property is not desirable for a good pseudo-random number generator? -
Answer-We must be able to look up the series of PRNs from a table.
Good pseudo-random number genator
- The numbers must appear to be Unif(0,1)
- The numbers are approximately independent
- We should we able to generate the PRNs very, very quickly
- We can reproduce any sequence of PRNs if called upon to do so
