Editing Knapsack problem (section)

===Multi-dimensional objective===
Here, instead of a single objective (e.g. maximizing the monetary profit from the items in the knapsack), there can be several objectives. For example, there could be environmental or social concerns as well as economic goals. Problems frequently addressed include portfolio and transportation logistics optimizations.<ref>Chang, T. J., et al. [http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.109.6698&rep=rep1&type=pdf Heuristics for Cardinality Constrained Portfolio Optimization].
Technical Report, London SW7 2AZ, England: The Management School, Imperial
College, May 1998</ref><ref>Chang, C. S., et al. "[https://scholarbank.nus.edu.sg/handle/10635/72660 Genetic Algorithm Based Bicriterion Optimization for Traction Substations in DC Railway System]." In Fogel [102], 11-16.</ref>

As an example, suppose you run a cruise ship. You have to decide how many famous comedians to hire. This boat can handle no more than one ton of passengers and the entertainers must weigh less than 1000&nbsp;lbs. Each comedian has a weight, brings in business based on their popularity and asks for a specific salary. In this example, you have multiple objectives. You want, of course, to maximize the popularity of your entertainers while minimizing their salaries. Also, you want to have as many entertainers as possible.