Judul: Shoreline Changes in the Coastal of Sungai  Limau Subdistrict, Padang Pariaman Regency, West Sumatra Province
Abstrak: Pesisir merupakan wilayah peralihan antara darat dan laut sehingga sangat potensial sebagai lokasi pembangunan. Pembangunan kawasan pesisir yang semakin pesat menyebabkan adanya perubahan tata guna lahan. Penelitian ini dilakukan untuk mendeteksi perubahan garis pantai Kecamatan Sungai Limau Kabupaten Padang Pariaman, Sumatra Barat tahun 2016-2020 menggunakan citra satelit sentinel. Laju perubahan garis pantai dihitung menggunakan metode Digital Shoreline Analysis System (DSAS). Parameter yang dibutuhkan dalam metode DSAS yaitu baseline, shoreline, dan transect. Perubahan garis pantai pada transek dihitung dengan perhitungan End Point Rate (EPR) dan Net Shorline Movement (NSM). Abrasi terjadi pada semua zona yang meliputi Desa Pilubang, Desa Kuranji Hilir, Desa Koto Tinggi dan Desa Guguak. Desa Pilubang mengalami abrasi terbesar dengan perubahan garis pantai 114,59 meter. Desa Kuranji Hilir mengalami abrasi sebesar 94,60 meter, Desa Koto Tinggi mengalami abrasi sebesar 86,93 meter dan Desa Guguak mengalmi perubahan garis pantai berupa abrasi sebesar 78,72 meter. Perubahan garis pantai yang terjadi di pesisir Pantai Sungai Limau dipengaruhi oleh arus (0,12 – 0,25 m/s), angin (5 – 2 m/s), gelombang (0,3 – 0,93 meter) dan pasang surut (-0,6 – 0,8 meter). Arus yang bergerak menyusuri pantai yang terbentuk akibat angin dan gelombang yang ada di pesisir Kecamatan Sungai Limau mengakibatkan terjadinya abrasi., The coast is a transitional area between land and sea so it is very potential as a location for construction. The rapid development of coastal areas causes changes in land use. This research was conducted to detect changes in the coastline of Sungai Limau Subdistrict, Padang Pariaman Regency, West Sumatra Province from 2016- 2020 using sentinel satellite imagery. The rate of shoreline change was calculated using the Digital Shoreline Analysis System (DSAS) method. The parameters needed in the DSAS method are baseline, shoreline, and transect. The shoreline change on the transect is calculated by the End Point Rate (EPR) and Net Shoreline Movement (NSM) formulas. Abrasion occurred in all zones which include Pilubang Village, Kuranji Hilir Village, Koto Tinggi Village, and Guguak Village. Pilubang Village experienced the biggest abrasion with a coastline change of 114.59 meters. Kuranji Hilir Village experienced an abrasion of 94.60 meters, Koto Tinggi Village experienced an abrasion of 86.93 meters and Guguak Village experienced a change in the coastline in the form of abrasion of 78.72 meters. Coastline changes that occur on the coast of Sungai Limau are influenced by currents (0.12 – 0.25 m/s), wind (5 – 2 m/s), waves (0.3 – 1.42 meters) and tides (-0.6 – 0.8 meters). Currents that move along the coast formed by wind and waves on the coast of Sungai Limau District cause abrasion.
Keyword: abrasi, akresi, citra sentinel, DSAS, garis pantai

Judul: Detection of Coastline Changes Using Landsat Satellite  Imagery in the Coastal of Padang City
Abstrak: Garis pantai selalu mengalami perubahan yang diakibatkan oleh faktor alam maupun non alam. Perubahan garis pantai perlu dipantau untuk mencegah hal-hal yang tidak diinginkan. Teknologi pengindraan jauh citra satelit sudah banyak digunakan dalam pemantauan garis pantai, salah satunya menggunakan Citra Landsat. Tujuan penelitian ini adalah mendeteksi perubahan garis pantai dengan menggunakan citra satelit multi temporal di pesisir Kota Padang dengan metode Digital Shoreline Analysis System (DSAS). Hasil dari Metode DSAS adalah nilai perubahan garis pantai yang mempunyai nilai positif dan negatif. Nilai positif berarti pantai mengalami akresi dan nilai negatif berarti pantai mengalami abrasi. Garis pantai di Padang umumnya mengalami kemunduran akibat proses abrasi. Laju abrasi terbesar terjadi di Desa Air Manis. Sementara itu, proses akresi terbesar yang menyebabkan penambahan garis pantai terjadi di di Desa Purus. Faktor-faktor yang menyebabkan terjadinya abrasi adalah terjangan gelombang dan arus sehingga terjadinya kemunduran garis pantai. Faktor-faktor yang menyebabkan terjadinya akresi adalah reklamasi pantai dan proses sedimentasi oleh aliran sungai., The coastline always changes due to natural and non-natural factors. Coastline changes need to be monitored to prevent unwanted things. Satellite image remote sensing technology has been widely used in monitoring coastlines, one of them is Landsat imagery. The purpose of this study was to detect coastline changes using multi-temporal satellite imagery on the coast of Padang City using the Digital Shoreline Analysis System (DSAS) method. The result of the DSAS method is the value of the coastline change that has positive and negative values. A positive value means the beach is accretion and a negative value means the beach is abrasion. The coastline in Padang generally had setbacks because of abrasion. The largest pace of abrasion in Air Manis Village. Meanwhile, the largest accretion process affected coastline additions in Purus Village. The factors of abrasion are the lunge of waves and sea waves so the setback coastline happens. The factors of accretion are beach reclamation and sediment process of river flow.
Keyword: abrasion, accretion, coastline, DSAS, Padang City

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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