Judul: Analisis Biaya Penanaman Jabon Putih (Anthocephalus cadamba) di Areal Penelitian Tanam Rumpang PT. Sarmiento Parakantja Timber
Abstrak: Tanam rumpang merupakan salah satu metode yang digunakan dalam merehabilitasi hutan dan lahan. Tujuan dari penelitian ini adalah mengetahui biaya kegiatan penanaman jabon putih dalam rumpang pada areal penelitian tanam rumpang di areal IUPHHK-HA PT. Sarmiento Parakantja Timber. Metode yang digunakan dalam penelitian ini adalah metode time study dan analisis biaya. Hasil penelitian menunjukkan bahwa untuk menyelesaikan penanaman rumpang seluas 3.2 ha di dalam areal plot penelitian seluas 10 ha yang dilakukan 4-5 pekerja diperlukan waktu 36-37 hari. Tenaga kerja yang diperlukan untuk menyelesaikan penanaman rumpang adalah 32.58 HOK per ha. Rata-rata biaya aktual dan standar penanaman rumpang berturut-turut adalah Rp. 12.534.433,28 per ha dan Rp. 13.508.759,66 per ha. Proporsi biaya penanaman terbesar adalah penyediaan bahan untuk kegiatan penanaman, yakni sebesar 40.30%. Biaya total aktual dengan biaya standar memiliki perbedaan. Perbedaaan tersebut dikarenakan pada penentuan biaya standar dibedakan waktu efektif dan waktu tidak efektif serta penilaian rating performance dan allowance., Gap planting is one of the methods used in rehabilitation of degraded forest and land. The objective of this research was to determine the cost of planting white jabon in the research area of gap planting in the IUPHHK-HA PT. Sarmiento Parakantja Timber. The method used in this research were the time study and cost analysis methods. The results showed that to complete the gap planting of a 3.2 ha in an area of 10 ha of research plots carried out by 4-5 workers took 36-37 days. Labour needed to finish gap planting was 32.58 mandays. ha-1. Average the actual and standard cost of gap planting respectively were 12.534.433,28 Rp.ha-1 and 13.508.759,66 Rp.ha-1. The largest portion of planting costs is on planting materials for planting activities, namely 40.30%. Actual total costs and standard costs have differences. The difference is due to determination of standard costs to differentiate between effective and ineffective times as well as the assessment of performance ratings and allowances.
Keyword: biaya, penanaman, rehabilitasi hutan, tanam rumpang

Judul: Cost Analysis of Maintenance of White Jabon (Anthocephalus cadamba) in the Gap Planting Research Plot Area of PT. Sarmiento Parakantja Timber
Abstrak: Tanam rumpang merupakan salah satu metode untuk merehabilitasi hutan dan lahan terdegradasi. Tujuan dari penelitian ini adalah mengetahui biaya kegiatan pemeliharaan jabon putih pada areal rumpang dalam areal plot penelitian PT. Sarmiento Parakantja Timber. Metode yang digunakan dalam penelitian ini terdiri dari metode time study, analisis biaya, dan uji statisik menggunakan Uji Independent sample t-test. Hasil penelitian menunjukkan untuk menyelesaikan kegiatan pemeliharaan rumpang dengan luas 3,2 ha membutuhkan waktu 8-9 hari dengan jumlah pekerja sebanyak 3-4 orang. Tenaga kerja yang diperlukan untuk menyelesaikan kegiatan pemeliharaan rumpang yaitu sebesar 7,15 HOK per ha. Rata-rata biaya aktual pemeliharaan yaitu sebesar Rp. 2.627.124,41/ha, sedangkan biaya standar pemeliharaan sebesar Rp. 2.861.007,53/ha. Proporsi biaya pemeliharaan terbesar pada kegiatan pemupukan sebesar 81%, diikuti oleh penyiangan sebesar 13%, dan pendangiran sebesar 6%. Kondisi topografi datar-landai dan topografi sedang-curam di areal rumpang tidak mempengaruhi biaya total pemeliharaan aktual maupun standar., Gap planting is one method used to rehabilitate degraded forests and land. The purpose of this study was to determine the cost of maintaining white jabon in the gap area in the research plot area of PT. Sarmiento Parakantja Timber. The method used in this study consisted of a time study method, cost analysis, and statistical tests using the independent sample t-test. The results showed that it took 8-9 days to complete maintenance activities in an area of 3.2 ha with a total of 3-4 workers. The labor required to complete the maintenance of the gap is 7.15 HOK per ha. The average actual cost of maintenance is Rp. 2,627,124.41/ha, while the standard maintenance cost is Rp. 2,861,007.53/ha. The biggest proportion of maintenance costs was 81% for fertilizing activities, followed by 13% for weeding and 6% for post planting soil tillage . Condition of flat-sloping topography and moderate-steep topography in the gap area do not affect the actual or standard total maintenance costs.
Keyword: cost, maintenance, orest rehabilitation, gap planting

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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