Judul: Soil Erosion Study in The Gap Planting Research Area  with Jabon Putih in The PT. Sarmiento Parakantja Timber
Abstrak: Peningkatan produktivitas hutan alam dapat dilakukan dengan menerapkan teknik tanam rumpang. Tujuan dari teknik tanam rumpang adalah untuk merehabilitasi hutan alam terdegradasi dengan penanaman fast growing species lokal non Dipterocarpaceae yang berdaur pendek (5-8 tahun) di dalam areal rumpang. Penelitian ini bertujuan untuk mendapatkan informasi erosi tanah yang terjadi akibat tanam rumpang pada kondisi areal hutan alam, simpukan dan jalur tanam. Penelitian dilakukan pada bulan Mei 2021. Penelitian dilakukan pada dua kelas kelerengan yaitu kelas datar-landai dan kelas sedang. Hasil uji statistik menunjukkan tidak berbeda nyata antara besarnya erosi tanah pada kelas lereng datar-landai dan kelas lereng sedang. Hasil penelitian menunjukan besar erosi tanah yang terjadi secara berturut-turut dari yang terbesar ke terkecil adalah di areal hutan alam, di areal jalur tanam dan di areal jalur simpukan., Increasing the productivity of natural forests can be done by applying the gap planting technique. The purpose of the gap planting technique is to rehabilitate degraded natural forests by planting local intolerant fast-growing species with short cycles (5-8 years) in the gap area. This study aims to obtain information on soil erosion that occurs due to gap planting activities on the condition of natural forest areas, erosion barrier strips, and planting strips. The study was conducted in May 2021. The study was conducted on two slope classes, the flat to sloping class and the moderate class. The result of statistical tests showed that the magnitude of erosion on the flat to sloping class and moderate class was not significantly. The results showed that the amount of soil erosion that occurred successively from the largest to the smallest was the area of natural forest, planting area, and erosion barrier area.
Keyword: erosi tanah, hutan alam terdegradasi, rehabilitasi, tanam rumpang, degraded natural forests, gap planting, rehabilitation, soil erosion

Judul: Studi Erosi Tanah Pada Areal Rumpang dan Hutan Alam Terdegradasi Di PT. Sarmiento Parakantja Timber
Abstrak: Tebang pilih tanam rumpang (TPTR) dan tanam rumpang tebang rumpang (TRTR) merupakan inovasi sistem silvikultur yang meniru proses suksesi dan permudaan alam di hutan alam yang sedang terus dikembangkan. Tujuan dari penelitian ini untuk mengetahui pengaruh tanam rumpang terhadap laju erosi tanah pada areal penelitian tanam rumpang dan hutan alam terdegradasi di PT. Sarmiento Parakantja Timber. Metode yang digunakan dalam penelitian ini adalah metode tongkat erosi serta uji statistik berupa uji anova dan uji independent. Hasil penelitian menunjukkan pengikisan tanah tertinggi terjadi pada areal hutan alam terdegradasi, diikuti di areal simpukan, dan yang terendah di areal jalur tanam. Uji statistik menunjukkan bahwa erosi yang terjadi pada kondisi areal hutan alam terdegradasi, jalur simpukan dan jalur tanam berbeda nyata. Pengaruh kelas lereng datar-landai dan kelas lereng sedang terhadap besarnya erosi di areal rumpang juga berbeda nyata. Namun besarnya erosi yang terjadi di areal rumpang dan di areal hutan alam terdegradasi tidak berbeda nyata., The silvicultural system of selective cutting and gap planting (TPTR) and the silvicultural system of gap planting and gap clear cutting (TRTR) are innovative silvicultural systems that mimic the process of succession and natural regeneration in natural forests, that are being developed. The purpose of this study was to determine the effect of gap planting on soil erosion rates in the research area of gap planting and natural forest of PT. Sarmiento Parakantja Timber. The method used in this research was the erosion stake method and statistical tests using anova tests and independent tests. The results showed that the highest soil erosion occurred in natural forest areas, followed by in the barrier areas, and the lowest in gap planting areas. Statistical tests showed that erosion that occurs in the condition of natural forest areas, gap planting areas, and barrier areas are significantly different. The effect of flat to sloping class and moderate slope class on the amount of erosion in the gap area was also significantly different. However, the amount of erosion that occurred in the gap planting area and in the degraded natural forest area was not significantly different.
Keyword: erosion stake, Gap planting, Natural forest, Slope, Soil erosion

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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