Judul: Soil Erosion Study in Gap Planting Research Area at PT. Intracawood Manufacturing
Abstrak: Sistem silvikultur Tanam Rumpang Tebang Rumpang (TRTR) merupakan salah satu upaya yang dapat diterapkan untuk mengembalikan fungsi lahan hutan yang mengalami degradasi. Sistem ini digunakan untuk merehabilitasi hutan alam yang rusak dengan penanaman fast growing species lokal non-Dipterocarpaceae maupun Dipterocarpaceae di areal rumpang. Penelitian ini bertujuan untuk mengetahui pengaruh dari tanam rumpang terhadap besarnya erosi tanah. Hasil penelitian menunjukan bahwa areal blok tanpa perlakuan memiliki nilai berat tanah tererosi terbesar. Areal blok perlakuan mengalami penimbunan. Uji statistik menunjukan bahwa besarnya erosi di areal rumpang yang diberi perlakuan tidak berbeda nyata terhadap besarnya erosi di areal rumpang tanpa perlakuan, besarnya erosi di areal rumpang yang diberi perlakuan tidak berbeda nyata terhadap besarnya erosi di hutan alam, dan besarnya erosi di areal rumpang tanpa perlakuan tidak berbeda nyata terhadap besarnya erosi di hutan alam., The silvicultural system of Gap Planting and Gap Felling (TRTR), is one of method that can be applied to restore the function of degraded forests. This system is used to rehabilitate damaged forests by planting of local fast-growing species of non-Dipterocarpaceae or Dipterocarpaceae in the gap. This study aims to determine the effect of gap planting on erosion rates. The results showed that natural forest in block area without treatment has the largest soil erosion weight rate. The treatment block area was piled up. Statistical analysis showed that the amount of erosion in the treated gap plot was not significantly different from the amount of erosion in the untreated gap plot, and the amount of erosion in the treated gap plot was not significantly different from the amount of erosion in natural forest, and the amount of erosion in the untreated gap plot was not significantly different from the amount of erosion in natural forests
Keyword: Degraded forest, gap planting, silviculture, 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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