Judul: Pengembangan Sistem Formulasi Ransum untuk Kebutuhan Ternak Ruminansia Menggunakan Linier Programming
Abstrak: Formulasi ransum merupakan aspek yang sangat esensial dalam menyeimbangkan nutrisi bagi hewan ternak dengan tujuan mendapatkan harga minimum berdasar pada kandungan nutrisi pakan hewan. Oleh karena itu peternak dituntut untuk mampu menyusun suatu formula ransum yang ekonomis tanpa mengabaikan faktor kebutuhan nutrisi ternak. Penelitian ini bertujuan untuk membuat suatu sistem pendukung pengambilan keputusan yang mampu melakukan formulasi ransum dengan mengadopsi metode linier programming. Metode pengembangan sistem yang dilakukan adalah prototype dengan evaluasi menggunakan perbandingan dengan aplikasi WinFeed 2.8 dan POM QM.
Keyword: formulasi ransum, linier programming, prototype, ternak ruminansia

Judul: Formulasi Ransum untuk Kebutuhan Nutrisi Ternak Sapi Potong Menggunakan Pemrograman Linier
Abstrak: Pakan mempunyai peranan penting dalam usaha peternakan khususnya dalam peningkatan produksi dan produktivitas ternak. Dari aspek ekonomi biaya pakan memberikan kontribusi hingga 70% dari seluruh biaya produksi. Besar biaya pakan ternak mendorong untuk membuat formula ransum ternak yang tidak hanya memenuhi kebutuhan nutrisi hewan ternak tetapi juga formulasi dengan biaya minimum. Penelitian ini membuat sistem yang mengoptimalkan kebutuhan nutrisi pakan menggunakan pemrograman linier dengan mempertimbangkan formula ransum dengan harga yang minimum. Hasil penelitian menunjukkan bahwa dengan melakukan 2 kali percobaan kombinasi dan menggunakan 5 jenis pakan menghasilkan persentase jenis pakan pada percobaan 1 yaitu rumput lapang 0.00%, bekatul 3.40%, ampas tahu 23.00%, rumput gajah 67.70%, dan centrosema 6.00% dengan harga minimum yaitu Rp 1470.29. Sedangkan percobaan 2 menghasilkan persentase jenis pakan yaitu rumput gajah 70.76%, daun grilicidia 29.24%, jerami padi, dedak padi dan tetes sebesar 0.00% dengan harga minimum Rp 690.88.
Keyword: formula ransum, nutrisi ternak, pemrograman linier

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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