Judul: Peramalan Harga Batu Bara Acuan Mengunakan Metode Autoregressive Integrated Moving Average dan Fungsi Transfer
Abstrak: Indonesia sebagai salah satu negara penghasil komoditas batu bara terbesar di dunia memiliki peranan yang penting dalam memenuhi permintaan batu bara di dunia global. Dewasa ini, sebagian besar negara-negara di Eropa kembali beralih kepada batu bara sebagai sumber tenaga pembangkit listriknya. Hal ini disebabkan adanya pandemi Covid-19 serta adanya konflik antara Rusia dan Ukraina yang membuat sumber energi menjadi terancam. Oleh sebab itu, peramalan harga batu bara diperlukan untuk menentukan kebijakan yang tepat dalam menghadapi banyaknya permintaan kebutuhan batu bara di masa mendatang. Pergerakan harga batu bara dipengaruhi oleh harga gas alam. Faktor harga gas alam tersebut akan dimodelkan dalam peramalan harga batu bara acuan menggunakan metode fungsi transfer sebagai deret inputnya. Penelitian ini membandingkan metode ARIMA dan fungsi transfer dalam peramalan harga batu bara acuan. Hasil penelitian ini menunjukkan bahwa model ARIMA dan model fungsi transfer secara berturut-turut menghasilkan nilai MAPE sebesar 23,14% dan 17,66%. Berdasarkan nilai MAPE yang dihasilkan metode fungsi transfer memiliki kemampuan peramalan yang lebih baik dibandingkan dengan metode ARIMA., Indonesia as one of the largest coal producing countries in the world has an important role in coal global demand. Currently, most countries in Europe are turning to coal as a source of electricity. This is due to Covid-19 pandemic and the conflict between Russia and Ukraine which endangers energy sources. Therefore, forecasting coal prices in the future is needed to determine the right policy in dealing with the large demand for coal. Coal price fluctuation are influenced by several factors such as the prices of the other commodities instance natural gas price. The natural gas price factor will be modeled in coal price forecasting using the transfer function method as the input series. This study compares the ARIMA and Transfer Function in coal price forecasting. The results showed that MAPE values of ARIMA and transfer function method are 23,14% and 17,66%. Based on MAPE values that forecasting using the transfer function method has a better ability than ARIMA method in forecasting coal prices.
Keyword: ARIMA, coal, transfer function

Judul: Penerapan Metode Generalized AutoRegressive Conditional Heteroskedasticity untuk Peramalan Harga Minyak Mentah Dunia.
Abstrak: Minyak mentah merupakan salah satu komoditas yang sangat dibutuhkan di berbagai bidang. Harga minyak mentah dunia yang terus mengalami fluktuasi tentunya mengambil pengaruh yang besar terhadap perekonomian negara. Data harga minyak mentah yang dikumpulkan bersifat time series atau proses pengumpulannya dilakukan dari waktu ke waktu dengan periode bulanan. Oleh karena itu, diperlukan suatu sistem yang dapat membuat peramalan harga minyak mentah dunia kedepannya yang diharapkan dapat menjadi bahan pertimbangan pemerintah untuk pengambilan keputusan. Salah satu metode yang dapat digunakan untuk meramalkan harga minyak mentah dunia adalah ARIMA (Auto-Regressive Integrated Moving Average) dan model GARCH (Generalized Auto-Regressive Conditional Heteroskedasticity). Pemodelan yang dilakukan terbukti bahwa data harga minyak mentah dunia periode Januari tahun 2002 hingga Juni 2022 memiliki efek heteroskedastisitas yang tidak dapat diatasi jika hanya menggunakan model ARIMA. Hasil dari pengolahan data diperoleh bahwa model ARIMA (0,1,2) yang dilanjutkan model ARCH (2) merupakan model terbaik dengan nilai MAPE sebesar 5,32%. Nilai akurasi yang diperoleh tergolong sangat baik untuk peramalan harga minyak mentah dunia., Crude oil is one of the commodities that are needed in various fields. World crude oil prices that continue to fluctuate, of course, have a big influence on the country's economy. Crude oil price data collected is time series or the collection process is carried out from time to time with monthly periods. Therefore, we need a system that can forecast future world crude oil prices which are expected to be taken into consideration by the government for decision making. One method that can be used to predict world crude oil prices is ARIMA (Auto-Regressive Integrated Moving Average) and GARCH (Generalized Auto-Regressive Conditional Heteroskedasticity) model. After modeling, it is proven that the world crude oil price data for the period January 2002 to June 2022 has a heteroscedasticity effect that cannot be overcome if only using the ARIMA model. The results of data processing show that the ARIMA (0,1,2) followed by the ARCH model(2) is the best model with a MAPE value of 5,32%. The accuracy values obtained are classifield as very good for forecasting world crude oil prices.
Keyword: ARIMA, ARCH, GARCH, harga minyak mentah, peramalan

Judul: Etno-ornitologi Burung Kancilan Flores (Pachycephala nudigula nudigula Hartert 1897) pada Masyarakat Lio di Taman Nasional Kelimutu
Abstrak: Bare-throathed whistler is one of several wild birds in Kelimutu National Park (TNKL) that is believed to have correlation with Lio Community‟s belief. The estimation of Bare-throated whistler‟s population in Kelimutu National Park was about 186.41-1668.07 individual by the density about 0.0389-0.3481 ind/ha with the sex ratio 6.2:1 that spreaded on area with height of 1100 – 1600 masl. The characteristic of Bare-throated whistler‟s habitat is a natural forest with various canopy level, high plant species diversity and high density. The habitat characteristics related to the availability of food in the form of insects, cover, safety and a nesting site. Generally the most of Lio community knew the existence of Bare-throated whistler directly or from their parents‟ stories. The perceptions of Lio Community to the Bare-throated whistler‟s existence is generally support the conservation efforts. The perceptions construct the Lio Community‟s atitude that tend to be conservative to the existence of Bare-throated whistler. The attitude shown by their behavior that not cathing the Bare-throated whistler from the TNKL‟s area or the outside. The attitude have an important role to the existence of Bare-throated whistler in Kelimutu National Park‟s area.
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