mindset ( m athematics in struction using d ecision s cience and e ngineering t ools ) a ssignment...
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MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
ASSIGNMENT
Sponsored by the National Science Foundation, Directorate for Education and Human Resources, project DRL-0733137
CHAPTER 6
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
Chapter 6 Organization
• 6.1 Coach Bass’s Problem• 6.2 The Medley Relay Team
▪ Hungarian Algorithm▪ Excel Solver
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
6.1 Coach Bass’s Problem
• Coach Bass is a swim coach who must assign four swimmers to compete in the 400 yard medley
▪ 100 yard Butterfly▪ 100 yard Backstroke▪ 100 yard Breaststroke▪ 100 yard Freestyle
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
6.2 Medley Relay Team
• Who should swim what leg of the relay?
Swimmer100yd Fly
(sec)100yd Back
(sec)100yd Breast
(sec)100yd Free
(sec)
Schmidt 59.59 59.83 72.83 52.61
Reid 60.45 59.56 74.14 53.31
Sanchez 61.84 64.63 73.69 53.70
Lamartina 62.37 59.13 74.36 54.77
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
6.2 Medley Relay Team – Hungarian Algorithm
• The Hungarian Algorithm will help us easily determine which swimmer to swim which leg of the relay
• The algorithm is designed specifically to solve assignment problems
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
6.2 Medley Relay Team – Hungarian Algorithm
• Using the flow chart on p. 3
(Figure 5.2.1), follow the
algorithm to determine the
swimmers assignments • n denotes the size of the
n x n square matrix• The algorithm only works for
square matrices
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
6.2 Medley Relay Team – Final Matrix
• But what does this mean?
Swimmer100yd Fly
(sec)100yd Back
(sec)100yd Breast
(sec)100yd Free
(sec)
Schmidt 0 2.62 0.39 0.16
Reid 0 1.49 0.84 0
Sanchez 1 6.17 0 0
Lamartina 0.86 0 0 0.4
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
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6.2 Medley Relay Team – Solution
Swimmer100yd Fly
(sec)100yd Back
(sec)100yd Breast
(sec)100yd Free
(sec)
Schmidt Reid Sanchez Lamartina
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
6.2 Medley Relay Team – Complication
• Swimmer Wu has joined the team ▪ but the algorithm only works for square
matrices
Swimmer100yd Fly
(sec)100yd Back
(sec)100yd Breast
(sec)100yd Free
(sec)
Schmidt 59.59 59.83 72.83 52.61
Reid 60.45 59.56 74.14 53.31
Sanchez 61.84 64.63 73.69 53.70
Lamartina 62.37 59.13 74.36 54.77
Wu 60.33 64.30 72.74 54.05
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
6.2 Medley Relay Team – Complication
• Add a dummy task (or people if necessary) and continue with the Hungarian Algorithm
Swimmer 100yd Fly (sec)
100yd Back(sec)
100yd Breast(sec)
100yd Free(sec) Dummy
Schmidt 59.59 59.83 72.83 52.61 0
Reid 60.45 59.56 74.14 53.31 0
Sanchez 61.84 64.63 73.69 53.70 0
Lamartina 62.37 59.13 74.36 54.77 0
Wu 60.33 64.30 72.74 54.05 0
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
6.2 Medley Relay Team – Even More Complication
Swimmer 100yd Fly (sec)
100yd Back(sec)
100yd Breast(sec)
100yd Free(sec)
Schmidt 59.59 59.83 72.83 52.61
Reid 60.45 59.56 74.14 53.31
Sanchez 61.84 64.63 73.69 53.70
Lamartina 62.37 59.13 74.36 54.77
Wu 60.33 64.30 72.74 54.05
Greene 62.41 64.34 66.19 56.61
Kleinfeld 62.43 67.63 74.05 55.55
Lepinski 59.44 65.06 72.74 52.49
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
6.2 Medley Relay Team – Even More Complication
• The new matrix would require performing the Hungarian Algorithm on a 8x8 matrix
• Is there a better way? ▪ Excel Solver!
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
6.2 Medley Relay Team – LP Formulation
• Write out▪ Decision Variables▪ Objective Function▪ Constraints
• Create Excel Spreadsheet▪ Input decision objective function, constraints,
RHS constraint values• Use Solver to find the solution
▪ Output final values, objective function value, LHS constraint values
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
6.2 Medley Relay Team – Decision Variables and Objective Function
• What values are changing in this assignment problem?
▪ Who swims which leg• How are we going to determine this assignment?
▪ Using binary variables• How many decision variables are there?
▪ 32• What is Coach Bass trying to accomplish when
assigning swimmers a leg of the relay?▪ Coach Bass is trying to minimize the total time
of the 400 yard Medley Relay
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
6.2 Medley Relay Team – Constraints
• Know the decision variables are binary▪ takes care of non-negativity
• How many swimmers can swim each stroke in the race?
• Will all the swimmers swim?
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
6.2 Medley Relay Team – Yucky Excel Spreadsheet
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
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6.2 Medley Relay Team – A Better Excel Spreadsheet
Every swimmer swims at most one leg.
Every leg has exactly one swimmer.
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
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6.2 Medley Relay Team – Excel Spreadsheet
= SUMPRODUCT(C7:F14,C19:F26)
= SUM(C19:F19)
= SUMC26:F26)
= SUM(C19:C26) … = SUM(F19:F26)
Every swimmer swims at most one leg.
Every leg has exactly one swimmer.
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
6.2 Medley Relay Team – Solver
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
In Summary
• The Hungarian Algorithm is a useful tool for assigning tasks in the optimal scenario
• However, the Hungarian Algorithm can blow up quickly – but Excel Solver is there for the rescue
• Can solve assignment problems by setting up a binary linear programming formulation
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
Practice – 6.2.3
• Solve for the minimum total relay time using the Hungarian Algorithm
Swimmer100yd Fly
(sec)100yd Back
(sec)100yd Breast
(sec)100yd Free
(sec)
Schmidt 59.59 59.83 72.83 52.61
Reid 60.45 59.56 74.14 53.31
Sanchez 61.84 64.63 73.69 53.70
Lamartina 62.37 59.13 74.36 54.77
Wu 60.33 64.30 72.74 54.05
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
6.2.3 Solution
Swimmer 100yd Fly (sec)
100yd Back(sec)
100yd Breast(sec)
100yd Free(sec) Dummy
Schmidt Reid Sanchez Lamartina Wu
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
www.MINDSETproject.org
Practice – 6.HW.1
• 6.HW.1 is on p. 15• Use the Excel template from 6.2 to solve
MINDSET (Mathematics INstruction using Decision Science and Engineering Tools)
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5.HW.1 Solution