added core concepts lenses thumbnail
added core concepts lenses thumbnail
liangcun/ConceptsOfSpatialInformation,liangcun/ConceptsOfSpatialInformation,liangcun/ConceptsOfSpatialInformation,spatial-ucsb/ConceptsOfSpatialInformation,spatial-ucsb/ConceptsOfSpatialInformation,spatial-ucsb/ConceptsOfSpatialInformation