Judul: Monitoring System for Environmental and Water Quality at Mangrove Crab Hatchery in Brebes Regency, Central Java
Abstrak: Kepiting bakau merupakan salah satu komoditas perikanan yang memiliki potensi sebagai sumber kehidupan masyarakat, terutama bagi nelayan skala kecil. Ekosistem mangrove mempunyai peran penting sebagai habitat utama kepiting bakau (Scylla Sp). Kepiting bakau (Syclla Sp.) sering disebut sebagai kepiting lumpur, karena menggali dan menghuni liang di hutan bakau dan perairan intertidal dangkal yang lunak. Penyebaran Kepiting Bakau hampir di seluruh Kawasan pesisir Indonesia, yang memiliki ekosistem mangrove. Dalam proses pembudidayaan kepiting bakau, diperlukan beberapa parameter agar dapat mengetahui kondisi habitat kepiting secara langsung. Penelitian bertujuan menampilkan data yang didapatkan menggunakan rancang bangun sistem monitoring pada hatchery kepiting bakau di Brebes. Rancang bangun sistem monitoring pada hatchery kepiting bakau dinilai berhasil menampilkan data parameter lingkungan menggunakan perangkat lunak Blynk. Terdapat empat parameter yang ditampilkan, yaitu kelembaban udara, suhu udara, suhu air, dan jarak. Melalui analisis statistik deskriptif pada data bulan November didapatkan nilai kelembaban udara sebesar 65-98%, suhu udara sebesar 24-31°C, suhu air sebesar 27-34°C, dan jarak antara posisi sensor dengan permukaan air laut sebesar 17-69 cm. Berdasarkan data tersebut maka kualitas perairan di hatchery kepiting bakau, Kabupaten Brebes dinilai cocok untuk habitat kepiting bakau dan budidaya kepiting bakau., Mangrove crabs are a significant fishery commodity with the potential to support the livelihoods of local communities, particularly small-scale fishermen. Mangrove ecosystems play a crucial role as the primary habitat for mangrove crabs (Scylla spp.). Mangrove crabs (Scylla spp.) are often referred to as mud crabs because they burrow and inhabit burrows in mangrove forests and soft, shallow intertidal waters. The distribution of mangrove crabs spans almost all coastal areas of Indonesia with mangrove ecosystems. In the cultivation of mangrove crabs, several parameters are needed to directly assess the habitat conditions for the crabs. The study aims to present data obtained using a monitoring system design at a mangrove crab hatchery in Brebes. The design of the monitoring system at the mangrove crab hatchery was successful in displaying environmental parameter data using Blynk software. Four parameters were monitored air humidity, air temperature, water temperature, and distance. Through descriptive statistical analysis of data from November, the air humidity was found to range from 65-98%, air temperature from 24-31°C, water temperature from 27-34°C, and the distance between the sensor and the sea surface from 17-69 cm. Based on this data, the water quality at the mangrove crab hatchery in Brebes is deemed suitable for the habitat and cultivation of mangrove crabs.
Keyword: blynk, hatchery, kepiting bakau, Suhu, sistem monitoring

Judul: Analysis of Mangrove Crab Habitat Suitability in Mundupesisir Village, Cirebon
Abstrak: Hutan mangrove merupakan habitat utama bagi Scylla serrata yang dimanfaatkan secara berlebihan menyebabkan penurunan jumlah populasi kepiting bakau. Maka dari itu, diperlukan kesesuaian habitat kepiting bakau untuk pemanfaatan perikannan yang berkelanjutan. Analisis kesesuaian habitat kepiting bakau dilakukan menggunakan pendekatan nilai indeks kualitas habitat (IKH) yang disusun berdasarkan hasil modifikasi Tahmid et al. 2015. Hubungan antara keberadaan kepiting bakau dengan kualitas habitat kepiting bakau dianalisa dengan analisis statistik multivariabel yang didasarkan pada Analisis Komponen Utama (Principal Component Analysis). Total luasan mangrove yang diperoleh dari pengolahan Citra Sentinel-2A sebesar 7 ha dengan kelas kerapatan tertinggi berada pada kelas rapat dengan luas 6,72 ha dan terendah berada pada kelas jarang dengan luas 0,014 ha. Berdasarkan hasil analisis, habitat kepiting bakau di kawasan mangrove Desa Mundupesisir, Kabupaten Cirebon berada pada kategori sesuai dengan luas 5,73 ha dan sangat sesuai dengan luas 1,27 ha. Hasil analisis PCA menjelaskan bahwa parameter salinitas dan kerapatan mangrove paling berpengaruh dengan keberadaan kepiting bakau., Mangrove forests are the main habitat for Scylla serrata which are often overused which causes a decline in the population of mangrove crabs. Therefore, it is necessary to suit mud crab habitat for sustainable use of fisheries. Analysis of mangrove crab habitat suitability was carried out using the habitat quality index (IKH) value approach which was prepared based on the modified results of Tahmid et al. 2015. The relationship between the presence of mud crabs and the quality of mud crab habitat was analyzed using multivariable statistical analysis based on Principal Component Analysis. The total area of mangroves obtained from processing Sentinel-2A imagery is 7 ha with the highest density class being in the dense class with an area of 6.72 ha and the lowest being in the sparse class with an area of 0.014 ha. Based on the results of the analysis, mangrove crab habitat in the mangrove area of Mundupesisir Village, Cirebon Regency is in the suitable category with an area of 5.73 ha and very suitable with an area of 1.27 ha. The results of the PCA analysis explain that the salinity and density parameters of mangroves have the most influence on the presence of mangrove crabs.
Keyword: kesesuaian, habitat, PCA, IKH, Kepiting, mangrove

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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