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Full-Text Articles in Life Sciences
A Two-Stage Approach To Integrate Vessel Geo-Tracking Data And Logbooks For Monitoring Fishing Activity Of Coastal Fisheries In Waters Off Northwestern Taiwan, Yi-Jou Lee, Nan-Jay Su, Cheng-Hsin Liao, Wei-Chuan Chiang, Chun-Huei Li
A Two-Stage Approach To Integrate Vessel Geo-Tracking Data And Logbooks For Monitoring Fishing Activity Of Coastal Fisheries In Waters Off Northwestern Taiwan, Yi-Jou Lee, Nan-Jay Su, Cheng-Hsin Liao, Wei-Chuan Chiang, Chun-Huei Li
Journal of Marine Science and Technology
Catch and fishing effort data are fundamental information to stock assessment and fisheries management, but difficult to obtain without the support of administration and sound fishery data collection system. This study integrated various sources of data from a simplified vessel geo-tracking system and logbooks from interviews with captains of coastal gillnet fisheries. We developed a two-step approach based on hierarchical cluster analysis to characterize the operation patterns and infer the fishing activities of the fishery. Results showed that the fishing effort in terms of operation duration could be estimated precisely for various vessel sizes, with catch composition and harvest information …
Cluster Analysis Of Lithology Grouping Trends Using Principal Component Spectral Analysis And Complex Seismic Attributes, Isfan Isfan, Agustinus Harsono, Abdul Haris
Cluster Analysis Of Lithology Grouping Trends Using Principal Component Spectral Analysis And Complex Seismic Attributes, Isfan Isfan, Agustinus Harsono, Abdul Haris
Makara Journal of Science
Cluster analysis is used to determine possible lithology groupings on the basis of information from seismic data. Specifically, k-means is used in the cluster analysis of different lithologies. The data center is determined randomly and updated through an iterative process (unsupervised). The cluster analysis process involves combinations of complex seismic attributes and spectral decomposition as inputs. The complex seismic attributes are reflection strength and cosine phase. Reflection strength clearly describes the lithology boundary while the cosine phase describes the lithologies. Spectral decomposition is used to detect the presence of channels. The resolution of seismic data generally reaches 90 Hz. Spectral …