As each type of satellite network has different link features, its data transmission must be designed based on its link features to improve the efficiency of data transferring. The transmission of navigation integrate...As each type of satellite network has different link features, its data transmission must be designed based on its link features to improve the efficiency of data transferring. The transmission of navigation integrated services information (NISI) in a global navigation satellite system (GNSS) with inter-satellite links (ISLs) is studied by taking the real situation of inter-satellite communication links into account. An on-demand computing and buffering centralized route strategy is proposed based on dynamic grouping and the topology evolution law of the GNSS network within which the satellite nodes are operated in the manner of dynamic grouping. Dynamic grouping is based on satellites spatial relationships and the group role of the satellite node changes by turns due to its spatial relationships. The route strategy provides significant advantages of high efficiency, low complexity, and flexi- ble configuration, by which the established GNSS can possess the features and capabilities of feasible deployment, efficient transmission, convenient management, structural invulnerability and flexible expansion.展开更多
Waters off the coasts of West Africa are very rich with many different types of fish and marine life.Some species like sardines,tuna,mackerel,tilapia and shrimps are important to many local communities and economies i...Waters off the coasts of West Africa are very rich with many different types of fish and marine life.Some species like sardines,tuna,mackerel,tilapia and shrimps are important to many local communities and economies in West Africa.However,the current overfishing of these fish affects the sustainability of fishery industry.Despite Ghana ratifying to a number of international marine laws to ensure a sustainable marine fishing,there seem to be some challenges that are associated with marine fishing in Ghana.This paper further examines the strategies that have been employed by the fishing community and the fisheries ministry in Ghana as a response to restrictive measures for the challenges identified and discussed in literature.This paper is fundamentally an extensive review of marine fisheries literature.In general terms,it was found that,Ghana has ratified to a number of international marine laws including the UNCLOS.展开更多
文摘As each type of satellite network has different link features, its data transmission must be designed based on its link features to improve the efficiency of data transferring. The transmission of navigation integrated services information (NISI) in a global navigation satellite system (GNSS) with inter-satellite links (ISLs) is studied by taking the real situation of inter-satellite communication links into account. An on-demand computing and buffering centralized route strategy is proposed based on dynamic grouping and the topology evolution law of the GNSS network within which the satellite nodes are operated in the manner of dynamic grouping. Dynamic grouping is based on satellites spatial relationships and the group role of the satellite node changes by turns due to its spatial relationships. The route strategy provides significant advantages of high efficiency, low complexity, and flexi- ble configuration, by which the established GNSS can possess the features and capabilities of feasible deployment, efficient transmission, convenient management, structural invulnerability and flexible expansion.
文摘Waters off the coasts of West Africa are very rich with many different types of fish and marine life.Some species like sardines,tuna,mackerel,tilapia and shrimps are important to many local communities and economies in West Africa.However,the current overfishing of these fish affects the sustainability of fishery industry.Despite Ghana ratifying to a number of international marine laws to ensure a sustainable marine fishing,there seem to be some challenges that are associated with marine fishing in Ghana.This paper further examines the strategies that have been employed by the fishing community and the fisheries ministry in Ghana as a response to restrictive measures for the challenges identified and discussed in literature.This paper is fundamentally an extensive review of marine fisheries literature.In general terms,it was found that,Ghana has ratified to a number of international marine laws including the UNCLOS.