View full-text article in PMC Sensors (Basel). 2019 May 26;19(10):2403. doi: 10.3390/s19102403 Search in PMC Search in PubMed View in NLM Catalog Add to search Copyright and License information © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). PMC Copyright notice Algorithm 3 Compute the minimum cost of line barrier 33. Input: T¯={{T11,T12,...,T1M1},...,{Tq1,Tq2,...,TqMq}},R¯={R1,R2,...,RN},L 34. Output: the minimum cost C*, the approximate optimization barrier P* 35. for i←1:q 36. For j←1:Cqi //Cqi denotes selecting i transmitters from q transmitters 37. Generate a transmitter set STj which the set size is i and one transmitter for each class 38. P←Algorithm-2(T¯,R¯) 39. C←Get_cost(P) //Compute the current minimum cost C 40. If C<C* 41. C*←C;P*←P 42. End If 43. End For 44. End For 45. Return (C*,P*)