Judul: Kajian proporsi bagian tubuh ikan dan kadar proksimat ikan gabus (Channa striata) pada berbagai ukuran
Abstrak: Snakehead (Channa striata) is a freshwater fish that known by Indonesian people. Snakehead is found in common waters and not yet cultivated widely. Snakehead live in outfall, lakes, swamp, and can also live in dirty water with low oxygen content and can resistant to drought. The purpose of this research is to know the body parts proportion of fish and chemical composition of flesh on any size and sex. Prosedure carried on research is measurement body proportion of fish and proximate analysis. The largest body part of snakehead found in flesh of 2 kg fish. The highest moisture and ashes content found on 0.5 kg male snakehead were 80.41 % and 1.47 %. The highest protein content was 20.14 % found on 1 kg female snakehead. The highest fat content was found on 2 kg male snakehead (1.69 %). The highest content of carbohydrate was found on 2 kg female snakehead (2.71 %).
Keyword: body proportions, proximate, snakehead (Channa striata)

Judul: Target Strength Measurement of Snakehead Fish (Channa striata Bloch 1793) Juveniles Using Hydroacoustic Method under Controlled Conditions
Abstrak: Ikan Gabus (Channa striata) merupakan ikan karnivora yang banyak ditangkap karena rasa dagingnya yang gurih dan mudah ditemukan di perairan berlumpur, rawa-rawa, kolam, perairan sungai. Ikan gabus anakan lebih banyak ditangkap sebagai pakan untuk ikan hias lainnya, ancaman terhadap anakan gabus secara terus menerus dapat berakhir dengan kepunahan. Hal ini menjadi penting untuk menganalisa hubungan antara Target strength (TS) dengan panjang total anakan ikan gabus menggunakan instrumen echosounder SIMRAD EK15. Pengolahan data target strength 15 ikan gabus dengan rentang panjang badan 10-15 cm dilakukan dalam perangkat lunak echoview versi demo menggunakan metode digitasi per 1 ping dengan thresholding diantara -70 dB hingga -30 dB. Nilai TS yang diperoleh memiliki rata-rata -46.80 dB sampai -45.01 dB. Analisis hubungan antara panjang total dan nilai TS anakan ikan gabus memiliki hubungan yang sangat kuat yang ditunjukkan oleh koefisien regresi sebesar 85.31% dan persamaan TS= 64.439ln(L) – 215.66., Snakehead fish (Channa striata) is a carnivorous fish that is widely caught for the savory meat taste and easy to found in muddy waters, swamps, ponds, river waters. Snakehead fish juveniles are mostly caught as food for other ornamental fish, Threats that continuously run over the snakehead fish’s juveniles might makes them end up in extinction. It’s become important to analyse the relationship between Target Strength (TS) and the total length of snakehead fish’s juveniles using SIMRAD EK 15 echosounder. The target strength data of 15 snakehead fish with body length range of 10-15 cm is processed using the demo version of echoview by digitizing each ping and applying threshold between -70dB to -30dB. Results of the average value of TS ranged from -46.80 dB to -45.01 dB. The relationship between total length and TS value of snakehead fish has a strong relationship, which is indicated by regression coefficient of 85.31% and the equation TS = 64,439ln(L) – 215.66
Keyword: hydroacoustic, juvenile, SIMRAD EK 15, snakehead fish, target strength

Judul: Bifurkasi Hopf pada Model Siklus Bisnis Kaldor Kalecki tanpa dan dengan Waktu Tunda
Abstrak: Business cycle model is one of dynamical system models in economic. One of the business cycles model is Kaldor-Kalecki model. Kaldor-Kalecki business cycle model that is written in delayed defferential equations, is a business cycle model that involves gross product and capital stock of a company. In this paper Kaldor-Kalecki business cycle model is analyzed using both nondelay and delay in time of capital stock. By Taylor expansion for the time delayed model, an analysis of stability around the fixed points has been done. Furthermore, by using Hopf bifurcation theorem, it can be shown that there exists periodic orbits and limit cycle. In the nondelayed model, changing the parameter of goods market could lead to the occurrence of Hopf bifurcation and the existence of limit cycle. Similarly, for the delayed model, it has been shown that changing the time delay parameter may result in the occurrence of Hopf bifurcation and limit cycle.
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