Judul: Tata Niaga dan Pendugaan Volume Perdagangan Ilegal Satwa Kakatua Kecil Jambul Kuning (Cacatua sulphurea) dan Kakatua Koki (Cacatua galerita)
Abstrak: Perburuan dan perdagangan ilegal satwaliar di Indonesia selain menyebabkan penurunan populasi di alam juga menyebabkan negara mengalami kerugian. Penelitian ini bertujuan untuk mengetahui alur tata niaga perdagangan kakatua kecil jambul kuning dan kakatua koki ilegal, karakteristik pelaku dan menduga volume juga nilai perdagangannya. Metode pengambilan data melalui wawancara dengan kriteria narasumber bergerak dibidang hukum, perdagangan, satwaliar seperti GAKKUM, BKSDA Jakarta, BEA Cukai dan putusan Mahkamah Agung. Data yang dipergunakan yaitu dari tahun 2015-2020, menggunakan analisis deskpritif kualitatif dan kuantitatif. Tiga jenis alur ditemukan dalam tataniaga ilegal burung kakatua kecil jambul kuning dan kakatua koki. Alur tata niaga yang paling sering terjadi adalah Redundant channels. Perdagangan dilakukan secara langsung, hybrid dan daring. Penelitian ini menemukan 20 transaksi dan dugaan volume perdagangan total 38 satwa yang diperdagangkan pada rentang 2015-2020. Pendugaan nilai perdagangan 2015-2020 burung kakatua kecil jambul kuning sebanyak Rp 28.450.000 dan burung kakatua koki sebanyak Rp 34.250.000 total keduanya adalah Rp 62.700.000., Poaching and illegal wildlife trade in Indonesia, apart from causing a decline in the population in the wild, is also detrimental to the state. This study aims to determine trade system, perperator characteristics and estimate the volume and value of Yellow-crested Cockatoo and Sulphur-crested illegal trade. The data collection method through interviews with the criteria of sources engaged in law, trade, wildlife such as GAKKUM, BKSDA Jakarta, BEA Cukai and Supreme Court decision. Data used are from 2015-2020, using qualitative and quantitative descriptive analysis. Three type are found in the illegal trade in yellow-crested cockatoos and chef's cockatoos. The most common trade system flow is redundant funnels. Trading is done in person, hybrid and online. The study found 20 transactions and estimated trading volume total is 38 animals traded between 2015-2020. The estimated trading value for the yellow-crested cockatoo in 2015-2020 is IDR 28,450,000 and Sulphur-crested cockatoo is IDR 34,250,000, both amounting to IDR 62,700,000.
Keyword: bird, cockatoo, illegaly, trade, wildlife

Judul: Tata Niaga dan Pendugaan Volume Perdagangan Ilegal Trenggiling (Manis javanica Desmarest 1822)
Abstrak: Perburuan dan perdagangan ilegal trenggiling menyebabkan penurunan populasi trenggiling di alam dan menyebabkan negara mengalami kerugian secara ekologi dan ekonomi. Penelitian ini bertujuan untuk mengidentifikasi alur tata niaga, karakteristik pelaku, serta menduga volume dan nilai perdagangan ilegal trenggiling. Metode yang digunakan yaitu wawancara dengan staf BKSDA Jawa tengah dan BKSDA Yogyakarta, dan studi literatur. Data yang digunakan yaitu data operasi perdagangan satwa liar ilegal tahun 2015-2020 dari Ditjen GAKKUM-KLHK, GAKKUM Sumatera, BKSDA Yogyakarta, BKSDA Jawa Tengah, dan penelusuran dokumen melalui SIPP MA. Data dianalisis menggunakan deskriptif kualitatif dan kuantitatif. Hasil penelitian mengidentifikasi 5 jenis alur tata niaga ilegal yang didominasi oleh jenis alur restricted access 49% dan multiple barriers to market 25%. Alur tata niaga melibatkan warga lokal, bersifat tertutup dan kompleks. Pelaku merupakan usia produktif dan didominasi oleh laki-laki. Pemburu cenderung memiliki mata pencaharian sebagai buruh dan perantara sebagai pedagang. Bagian yang dijual dari trenggiling yaitu trenggiling utuh, sisik dan dagingnya dengan volume perdagangan ilegal trenggiling periode 2015-2020 sejumlah 4100 ekor dan nilai perdagangannya sebesar Rp6.032.202.989,00., Poaching and illegal trade in sunda pangolins cause a decline in population in the wild and detrimental to the country ecologically and economically. This study aims to identify the flow of commerce system, perpetrator’s characteristics, and to estimate the volume and value of illegal trade pangolins. The method used was an interview with the staff of BKSDA Central Java, BKSDA Yogyakarta, and literature studies. Used are data on illegal wildlife trade operations in 2015-2020 from the Directorate General of GAKKUM-KLHK, GAKKUM Sumatra, BKSDA Yogyakarta, BKSDA Central Java, document search through SIPP MA. Data analysis using qualitative and quantitative descriptive. There were 5 types of illegal pangolin commerce systems which were dominated by 49% restricted access and 25% multiple barriers to market. The flow of commerce system involves residents, is closed and complex. Perpetrators are productive age, dominated by men. Hunters tend to have a livelihood as laborers and intermediaries as traders. The parts that are sold from pangolins are whole pangolins, scales, and meat. The illegal trade volume of pangolins for the 2015-2020 period was 4100 animals and illegal trade value was IDR 6.032.202.989.
Keyword: tata niaga, trenggiling, volume perdagangan, commerce system, sunda pangolin, trading volume

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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