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: The Effect of Slopes on Soil Erosion in the Gap Planting Research Area of PT Sarmiento Parakantja Timber
Abstrak: Tanam Rumpang Tebang Rumpang (TRTR) merupakan sistem silvikultur yang diharapkan menjadi solusi peningkatan produktivitas hutan alam terdegradasi menggunakan teknologi tanam rumpang. Areal rumpang dimanfaatkan dengan menanam jenis pohon komersial setempat yang cepat pertumbuhannya dan berdaur pendek (5-8 tahun). Penelitian ini bertujuan untuk mengetahui pengaruh lereng terhadap erosi tanah yang terjadi akibat tanam rumpang. Penelitian dilakukan pada dua kelas lereng yakni kelas datar-landai dan kelas sedang. Hasil penelitian menunjukkan erosi tanah yang terjadi tertinggi pada areal simpukan, diikuti oleh erosi tanah di areal jalur tanam, dan yang terendah di areal hutan alam. Uji statistik menunjukkan bahwa erosi yang terjadi pada kondisi areal hutan alam, jalur simpukan dan jalur tanam tidak berbeda nyata. Pengaruh kelas lereng datar-landai dan kelas lereng sedang terhadap besarnya erosi di areal rumpang tidak berbeda nyata. Demikian pula besarnya erosi yang terjadi di areal rumpang dan di areal hutan alam terdegradasi juga tidak berbeda nyata., The gap planting and gap clear cutting (TRTR) silviculture system is projected to boost the productivity of damaged natural forests utilizing gap planting technology. The gap area is used by planting a local commercial fast-growing tree species with short-rotation (5-8 years). The goal of this study is to know how slopes affect soil erosion caused by gap planting. The study was conducted in two slope classes, namely the flat to sloping class and the medium class. The results showed that soil erosion occurred the highest in barrier areas, followed by soil erosion in planting path areas, and the lowest in natural forest areas. According to statistical analysis, there were no significant differences in the erosion that took place on planting path areas, barrier paths, and natural forest areas. The amount of erosion in the gap area is not considerably different depending on whether the slope is flat to sloping or medium. Similarly, the amount of erosion that occurs in the gap areas and in the degraded natural forest area is also not significantly different.
Keyword: Degraded natural forest, Gap planting, Soil erosion, Slopes

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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