Judul: Systematic Review: Condition and Challenges Harvesting Non-timber Products in Indonesia
Abstrak: Pemanenan HHBK merupakan kegiatan yang memanfaatkan hasil hutan berupa tumbuhan selain kayu dan hewan. Masyarakat yang tinggal disekitar hutan banyak memanfaatkan HHBK untuk memenuhi kebutuhan sehari-hari. Penelitian bertujuan untuk mengetahui bagaimana kondisi dan tantangan dalam pemanenan HHBK di negara Indonesia. Penelitian dilakukan menggunakan metode systematic review dengan jumlah 48 artikel. Pengumpulan artikel open acces yang ditulis dalam Bahasa Indonesia dan Bahasa Inggris. Pemanenan HHBK di Indonesia dilakukan pada hutan produksi. Pemanenan banyak dilakukan oleh masyarakat dengan manfaat bahan pangan. Pengambil HHBK banyak dilakukan secara berkelompok oleh masyarakat dengan waktu pemanenan yang beragam. Pemanenan HHBK di Indonesia mempunyai tantangan dalam peningkatan nilai tambah, pembentukan kelompok pemanenan, dan inventarisasi HHBK. Jarak panen yang semakin jauh membutuhkan waktu yang lama dan tenaga yang lebih besar., NTFP harvesting is an activity that utilizes forest products in the form of plants other than wood and animals. Communities living around the forest use NTFPs to meet their daily needs. This study aims to determine the conditions and challenges in harvesting NTFPs in Indonesia. The study was conducted using a systematic review method with a total of 48 articles. Collection of open access articles written in Indonesian and English. NTFPs are harvested in Indonesia in production forests. Harvesting is mostly done by the community with the benefit of food. NTFPs are mostly taken in groups by the community with various harvesting times. NTFP harvesting in Indonesia has challenges in increasing added-value, forming harvesting groups, and NTFP inventory. Longer harvest distances require more time and more energy.
Keyword: Pemanenan HHBK, Pendapatan HHBK, Tantangan HHBK

Judul: Systematic Review: Environmentally Friendly Forest Harvesting in Indonesia.
Abstrak: Tinjauan Sistematis: Pemanenan Hutan Ramah Lingkungan di Indonesia. Dibimbing oleh AHMAD BUDIAMAN. Pemanenan kayu pada pengelolaan hutan alam masih menimbulkan permasalahan lingkungan. Teknik perencanaan serta pelaksanaan pemanenan kayu yang baik dan benar masih belum dipergunakan dalam pemanenan kayu di hutan alam Indonesia, sehingga dampak kerusakan yang ditimbulkan selama kegiatan pemanenan kayu masih tinggi. Tujuan penelitian ini yaitu untuk mengetahui dan menghimpun hasil penelitian mengenai pemanenan hutan ramah lingkungan berdampak rendah serta mengevaluasi kinerja teknik Reduced Impact Logging. Penelitian ini menggunakan metode systematic review. Jenis data yang dikumpulkan berupa artikel berbahasa Indonesia maupun Inggris, yang bersifat open access sebanyak 28 jurnal. Hasil penelitian menunjukkan bahwa pemanenan kayu konvensional yang dilaksanakan selama ini dilakukan tanpa perencanaan yang baik, teknik pelaksanaan yang buruk dan lemahnya pengawasan menyebabkan kerusakan lingkungan yang besar, sedangkan pemanenan kayu dengan teknik Reduced Impact Logging lebih banyak disarankan untuk digunakan dalam kegiatan pemanenan hutan di berbagai Negara karena bersifat ramah lingkungan dan mampu meminimalkan kerusakan yang terjadi., Systematic Review: Environmentally Friendly Forest Harvesting in Indonesia. Supervised by AHMAD BUDIAMAN. Timber harvesting in natural forest management still causes environmental problems. Planning techniques and the implementation of good and correct timber harvesting are still not used in timber harvesting in Indonesia's natural forests, so the impact of damage caused during wood harvesting activities is still high. The purpose of this study is to find out and collect the results of research on environmentally friendly forest harvesting with a low impact and evaluate the performance of the Reduced Impact Logging technique. This study used the systematic Reviu method. The type of data collected is in the form of Articles in Indonesian and English, which are open access as many as 28 journals. The results showed that conventional wood harvesting carried out so far was carried out without good planning, poor implementation techniques and weak supervision caused great environmental damage, while wood harvesting with the Reduced Impact Logging technique was more widely recommended to be used in forest harvesting activities in various countries because it is environmentally friendly and able to minimize the damage that occurs.
Keyword: conventional, low impact harvesting, reduced impact logging, sustainable forest harvesting

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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