Judul: Kajian Stok Ikan Tembang (Sardinella fimbriata) di Perairan Selat Sunda yang Didaratkan di Pelabuhan Perikanan Pantai Labuan, Banten
Abstrak: Fringescale sardinella (Sardinella fimbriata) is one of the economically important fish resources found in the Sunda Strait waters. High economic value with the increasing demand of fish makes it as one of the main targets of capture. This research was conducted to determine the actual condition of the fringescale sardinella stock based on landed at Coastal Fishing Port of Labuan, Banten. The amount of the observed fish was 636 individuals with male sex ratio of 1:1.2 to the female. The fringescale sardinella had negative allometrik growth and female and male asymptotic length ( ) were 207.32 mm and 175.11 mm, respectively. Spawning season seems to be occurred in August and September. The mean size of female and male reach sexual maturity was 163 mm and 153 mm, respectively. Exploitation rate of the fringescale sardinella more than 50%, meaning that this fish has an over fishing and it seem has a growth overfishing due to caught fishes are still young more than 70%.
Keyword: Sunda Strait, growth, exploitation rate, stock assesement, fringescale sardinella

Judul: Kajian Stok Ikan Tembang (Sardinella fimbriata Valenciennes, 1847) di Perairan Selat Sunda
Abstrak: Ikan tembang merupakan salah satu sumberdaya ikan pelagis kecil yang memiliki nilai ekonomis dan banyak diminati oleh masyarakat di perairan selat sunda. Tujuan penelitian ini adalah mengidentifikasi dan menjelaskan informasi mengenai stok ikan tembang (Sardinella fimbriata Valenciennes, 1847) di perairan Selat Sunda yang didaratkan di PPP Labuan, Banten. Penelitian dilakukan pada bulan Mei sampai Oktober 2018. Total ikan contoh yang diamati sebanyak 629 ekor. Hasil penelitian menunjukkan bahwa ikan tembang memiliki pola pertumbuhan alometrik negatif. Tingkat eksploitasi ikan tembang jantan sebesar 0,758 dan ikan tembang betina sebesar 0,697. Ukuran ikan pertama kali tertangkap lebih kecil dibandingkan ukuran pertama kali ikan matang gonad (Lc < Lm). Berdasarkan analisis model produksi surplus menggunakan model Fox, status stok ikan tembang belum mengalami overfishing. Laju eksploitasi ikan tembang jantan dan betina telah melebihi batas optimum sehingga menunjukkan ikan tembang telah mengalami eksploitasi berlebih (overexploitation). Upaya pengelolaan yang dapat dilakukan adalah pengendalian alat tangkap yang digunakan dan pembatasan jumlah alat tangkap.
Keyword: Ikan tembang, laju eksploitasi, pertumbuhan, stok

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
Keyword: