The affinity of mangrove species using Association and Cluster Index in North Coast of Jakarta and Segara Anakan of Cilacap, Indonesia

Hilmi E, Sari LK, Cahyo TN, Muslih, Mahdiana A, Samudra SR. 2021. The affinity of mangrove species using Association and Cluster Index in North Coast of Jakarta and Segara Anakan of Cilacap, Indonesia. Biodiversitas 22: 2907-2920. The affinity of mangrove species using association and cluster index describe relationship among mangrove species. The species association and clustering explain the degree of utilization of resources and space by mangrove species. The association and cluster also describe specific species adaptation in mangrove ecosystems. This paper was aimed to analyze species affinity using association and clustering index of mangrove species. The association index used Chi-square equation and the clustered index used Euclidian distance analysis. The results showed that (i) mangrove density in Segara Anakan (166-4000 trees ha-1) > North Jakarta (220-1100 trees ha-1). (ii) Nypa fruticans, Avicennia marina, Rhizophora stylosa and Rhizophora apiculata dominated in Segara Anakan of Cilacap, and Rhizophora stylosa and Avicennia marina dominated in North Jakarta (iii) The association index had 12 pairs of negative species association and 17 pairs of positive species association, but most of mangrove vegetations had no association. (iv) mangrove ecosystem in Segara Anakan and North Jakarta had four clusters with Euclidean distance (ED score) 484 to describe cluster between Bruguiera parviflora-Bruguiera sexangula until 76430847 to describe cluster among Bruguiera gymnorrhiza, Bruguiera parviflora, Ceriops decandra, Exoecaria agallocha, Nypa fruticans, Ceriops tagal, Rhizophora stylosa, and Sonneratia caseolaris

The Implementations of K-medoids Clustering for Higher Education Accreditation by Evaluation of Davies Bouldin Index Clustering

The need for data analysis in tertiary education every semester is needed, this is due to the increasingly large and uncontrolled data, on the other hand generally higher education does not yet have a data warehouse and big data analysis to maintain data quality at tertiary institutions is not easy, especially to estimate the results of university accreditation high, because the data continues to grow and is not controlled, the purpose of this study is to apply k-medoids clustering by applying the calculation of the weighting matrix of higher education accreditation with the data of the last 3 years namely length of study, average GPA, student and lecturer ratio and the number of lecturers according to the study program, so that it can predict accurate cluster results, the results of this study indicate that k-medoid clustering produces good cluster data results with an evaluation value of the Bouldin index davies cluster index of 0.407029478 and is said to be a good cluster result.

Placing social types through prosodic variation: An investigation of spatial meanings in Mainland China

This study examines how prosodic features evoke the spacial aspects of interactional meanings of well-known social types in Mainland China. Prosodic features (duration, pitch, voice quality) of the scripted performances of 18 prominent social types in China were measured acoustically and grouped by cluster analysis. Commonalities among types within each group were identified through a detailed analysis of meta-linguistic commentary collected from the internet. This paper focuses on three meaningful clusters: powerful bureaucratic types, disembodied voices, and “in-your-face” types. Members of each cluster share prosodic combinations and social profiles. More importantly, character types within each cluster index a specific interactional locale. Appropriation of their associated features could reproduce the social dynamics that is typical in that locale. The results highlight the situated use of sociolinguistic variables, and show that the prosodic features pattern structurally in the performances while indexing the historical-spatial settings of social interactions. This paper also considers place as an interactional and relational product of meaning making by these prosodic features.