Judul: Ameliorasi Iklim melalui Revegetasi Lahan Star Energy Geothermal, Sukabumi, Jawa Barat
Abstrak: Program revegetasi lahan SEGS ditujukan untuk memperbaiki atau memulihkan kondisi vegetasi yang terdegradasi. Program penanaman atau pemeliharaan ini dilakukan melalui kerjasama dengan TNGHS. Penelitian ini bertujuan mengkaji ameliorasi iklim dari program revegetasi dengan indikator perubahan suhu permukaan serta kerapatan tajuk. Penelitian ini dilaksanakan pada Februari-April 2024. Alat dan bahan yang digunakan meliputi Avenza Maps, GPS, peta lokasi, Microsoft Office (Word dan Excel), Google Earth, ArcGIS 10.8, ERDAS Imagine 2015, dan citra Satelit Landsat Sukabumi. Analisis data dilakukan dengan identifikasi tutupan lahan, analisis suhu permukaan, analisis FCD, dan analisis hubungan kerapatan tajuk dengan suhu permukaan. Hasil penelitian menunjukkan bahwa terdapat tren penurunan suhu permukaan dan peningkatan kerapatan tajuk dalam waktu 10 tahun. Selain itu, terdapat hubungan terbalik antara kerapatan tajuk dengan suhu permukaan dengan korelasi sebesar -65,76%. Hal tersebut menandakan adanya keberhasilan revegetasi pada lokasi penelitian yang ditunjukkan adanya proses ameliorasi iklim dan peningkatan kanopi hutan., The SEGS land revegetation program is aimed at improving or restoring the condition of degraded vegetation. This planting or maintenance program is carried out in collaboration with TNGHS. This research aims to examine climate amelioration from the revegetation program with indicators of changes in surface temperature and canopy density. This research was carried out in February-April 2024. The tools and materials used included Avenza Maps, GPS, location maps, Microsoft Office (Word and Excel), Google Earth, ArcGIS 10.8, ERDAS Imagine 2015, and Landsat Sukabumi Satellite imagery. Data analysis was carried out by identifying land cover, surface temperature analysis, FCD analysis, and analyzing the relationship between canopy density and surface temperature. The research results show that there is a trend of decreasing surface temperature and increasing canopy density within 10 years. In addition, there is an inverse relationship between canopy density and surface temperature with a correlation of -65.76%. This indicates the success of revegetation at the research location, which is indicated by a process of climate amelioration and an increase in the forest canopy.
Keyword: kerapatan kanopi hutan, korelasi, perbaikan iklim, suhu permukaan

Judul: Relationship between Leaf Area Index (LAI) and Microclimate in Star Energy Geothermal Salak Revegetation Land
Abstrak: Kegiatan sektor panas bumi yang menggunakan bahan bakar fosil menghasilkan CO2 yang dapat menimbulkan efek rumah kaca dan pemanasan global. Pelestarian lingkungan pasca tambang telah dilakukan oleh Star Energy Geothermal Salak dengan cara melakukan program revegetasi lahan. Penelitian ini bertujuan untuk mengkaji hubungan antara kerapatan tajuk dan iklim mikro dengan indikator suhu udara, kelembapan udara, dan intensitas cahaya matahari pada lahan revegetasi. Analisis data dilakukan dengan pengukuran suhu dan kelembapan udara, pengukuran intensitas cahaya matahari, pengambilan foto Leaf Area Index (LAI), dan metode analisis regresi linear berganda. Hasil penelitian menunjukkan bahwa terdapat hubungan antara suhu udara dan kelembapan udara sebagai variabel terikat dengan intensitas cahaya matahari dan LAI sebagai variabel bebas yang dapat dilihat dari hasil analisis regresi linear berganda. Model regresi dapat menjelaskan sebesar 43% perubahan pada variabel suhu udara dan sebesar 40% perubahan pada variabel kelembapan udara dapat dijelaskan oleh variabel independen dalam model. Selain itu, hasil akhir menunjukkan tajuk pohon yang rapat dapat memperbaiki kondisi iklim mikro di Star Energy Geothermal Salak., Geothermal sector activities that use fossil fuels produce CO2 which can cause the greenhouse effect and global warming. Environmental preservation has been carried out by Star Energy Geothermal Salak by conducting a land revegetation program. This study aims to assess the relationship between canopy density and microclimate with indicators of air temperature, air humidity, and sunlight intensity on revegetated land. Data analysis was carried out by measuring air temperature and humidity, measuring sunlight intensity, taking photos of Leaf Area Index, and multiple linear regression analysis methods. The results showed that there is a relationship between air temperature and air humidity as the dependent variable with sunlight intensity and LAI as independent variables which can be seen from the results of multiple linear regression analysis. The regression model can explain 43% of changes in the air temperature variable and 40% of changes in the air humidity variable can be explained by the independent variables in the model.In addition, the final results show that dense tree crowns can improve microclimateconditions at Star Energy Geothermal Salak.
Keyword: pemanasan global, iklim mikro, regresi linier berganda, microclimate, multiple linear regression, global warming

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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