scholarly journals Incorporating multiple ecological criteria in classical zero one selection algorithms

Web Ecology ◽  
2002 ◽  
Vol 3 (1) ◽  
pp. 48-55 ◽  
Author(s):  
D. P. Memtsas ◽  
P. G. Dimitrakopoulos ◽  
A. Y. Troumbis
Keyword(s):  
Set Covering ◽  
Covering Problem ◽  
Set Covering Problem ◽  
Optimal Solutions ◽  
Species List ◽  
Basic Set ◽  
Ecological Criteria ◽  
Conservation Values ◽  
Species Rarity ◽  
Selection Algorithms

Abstract. Avifauna on Greek wetland sites is used as a model for the implementation of the Set Covering Problem in selecting nature reserves. Three site conservation values, which depend on species presence, are used as selection criteria. Their calculation is based upon species richness, species rarity and species-danger status. The conservation values must be inserted in the linear programming problem’s objective function by the form of weighting factors. Optimal solutions according to the three ecological criteria are produced. These solutions belong to the set of alternative optimal solutions of the basic Set Covering Problem with no other criterion taken into account except that of the whole species-list coverage. The set of alternative optimal solutions is generated by the explicit exclusion method. The relative value of goal programming and weighing up-criteria methods in producing a unique solution based on the three criteria simultaneously is assessed. Both methods coincide with the same alternative solution that is thus regarded as the final optimal one incorporating all the three ecological criteria.

scholarly journals Multi-objective database queries in combined knapsack and set covering problem domains

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Sean A. Mochocki ◽  
Gary B. Lamont ◽  
Robert C. Leishman ◽  
Kyle J. Kauffman
Keyword(s):  
Relational Database ◽  
Set Covering ◽  
Covering Problem ◽  
Set Covering Problem ◽  
Database Queries ◽  
Multi Objective ◽  
Data Representations ◽  
Np Hard Problem ◽  
Institute Of Technology ◽  
The One

AbstractDatabase queries are one of the most important functions of a relational database. Users are interested in viewing a variety of data representations, and this may vary based on database purpose and the nature of the stored data. The Air Force Institute of Technology has approximately 100 data logs which will be converted to the standardized Scorpion Data Model format. A relational database is designed to house this data and its associated sensor and non-sensor metadata. Deterministic polynomial-time queries were used to test the performance of this schema against two other schemas, with databases of 100 and 1000 logs of repeated data and randomized metadata. Of these approaches, the one that had the best performance was chosen as AFIT’s database solution, and now more complex and useful queries need to be developed to enable filter research. To this end, consider the combined Multi-Objective Knapsack/Set Covering Database Query. Algorithms which address The Set Covering Problem or Knapsack Problem could be used individually to achieve useful results, but together they could offer additional power to a potential user. This paper explores the NP-Hard problem domain of the Multi-Objective KP/SCP, proposes Genetic and Hill Climber algorithms, implements these algorithms using Java, populates their data structures using SQL queries from two test databases, and finally compares how these algorithms perform.

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