Judul: Study of Gap Planting Impact to Soil Erosion on Rehabilitation Activities of Degraded Natural Forests in the PBPH Areal of PT SARPATIM
Abstrak: Pengembangan sistem silvikultur TPTR dan TRTR memerlukan informasi dampak tanam rumpang di areal hutan alam terdegradasi yang nantinya berdampak terhadap tanah hutan, terutama erosi tanah. Tujuan penelitian untuk mendapatkan informasi tingkat erosi tanah akibat kegiatan tanam rumpang di areal hutan alam terdegradasi serta bertopografi datar-landai dan sedang. Penelitian dilaksanakan pada Mei-September 2021 dengan pengambilan data sebanyak delapan kali di enam plot tanam rumpang dan enam plot hutan alam terdegradasi. Hasil uji statistik menunjukkan bahwa terdapat perbedaan nyata perlakuan teknologi tanam rumpang terhadap besar erosi tanah. Besar erosi tanah di rumpang bertopografi datar-landai dan sedang tidak berbeda nyata. Kesimpulan penelitian menunjukkan bahwa besarnya tanah tererosi yang terjadi berturut-turut dari terbesar ke terkecil ialah pada areal hutan alam terdegradasi, jalur tanam di rumpang, dan penyekat erosi di rumpang., The development of TPTR and TRTR silvicultural systems requires information on the impact of gap planting in degraded natural forest areals that might will have an impact on forest soils, especially soil erosion. The purpose of the research was to obtain information on the level of soil erosion due to the application of gap planting in degraded natural forest areals and with flat to sloping and moderate class topography. The research was carried out in May-September 2021 with data collection eight times in six gap planting plots and six degraded natural forest plots. The results of statistical tests showed that there were noticeable differences in the treatment of gap planting technology to the magnitude of soil erosion. Meanwhile, the magnitude of soil erosion in the gap flat to sloping topography and moderate topography did not show a noticeable difference. It is concluded, that the amount of eroded soil that occurred in order from the largest to the smallest was in the degraded natural forest areal, the planting stripe in the gap, and the erosion barrier in the gap.
Keyword: Degraded natural forests, Erosion, Gap planting technology, Rehabilitation

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: 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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