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: Model Peramalan Harga Minyak Mentah OPEC Menggunakan ARIMA melalui Ensemble Empirical Mode Decomposition
Abstrak: Harga minyak mentah dunia mengalami fluktuasi setiap harinya. Salah satu sumber minyak mentah yang diperdagangkan pada skala internasional yaitu minyak dari negara-negara pengekspor minyak mentah dunia yang tergabung dalam Organization of the Petroleum Exporting Countries (OPEC). Sekitar empat puluh persen dari total produksi minyak dunia merupakan produksi OPEC. Hal tersebut menjadikan peramalan harga minyak mentah OPEC sangat dibutuhkan untuk menjaga keseimbangan pasar minyak dunia. Data harga minyak yang fluktuatif dibuat lebih sederhana dan mudah diinterpretasikan dengan cara menerapkan metode Ensemble Empirical Mode Decomposition (EEMD). Metode EEMD menguraikan data menjadi sejumlah Intrinsic Mode Function (IMF) dan sisaan IMF. Pada penelitian ini dibandingkan model peramalan ARIMA dengan menggunakan data asli dan hasil dekomposisi berupa komponen IMF dan sisaan IMF. Perbandingan kedua metode dilihat berdasarkan keseluruhan dan rata-rata nilai MAPE hasil peramalan pada lima rentang waktu. Metode EEMD-ARIMA memiliki rata-rata nilai MAPE sebesar 9,09% dan simpangan baku nilai MAPE sebesar 7,39%. Peramalan harga minyak mentah OPEC pada bulan Januari-Agustus 2021 berkisar antara 42,22 sampai 60,6 US dollar per barel. Hasil akhir analisis pada penelitian ini menunjukkan bahwa metode ARIMA dengan data dekomposisi (EEMD-ARIMA) lebih baik dibandingkan metode ARIMA menggunakan data asli., World crude oil prices fluctuate every day. One source of crude oil traded is oil from crude oil exporting countries that are members of the Organization of the Petroleum Exporting Countries (OPEC). In the total of 40% of world crude oil is produced by OPEC. This makes forecasting the price of crude oil OPEC’s policy very necessary in order to maintain world oil market stability. Fluctuating oil price data is made simpler and easier to interpret by applying the Ensemble Empirical Mode Decomposition (EEMD) method. The EEMD method decomposes the data into a number of Intrinsic Mode Functions (IMF) and residual of the IMF. In this study, the ARIMA forecasting model is compared using the original data and the decomposition results in the form of IMF components and IMF residuals. The comparison of the two methods is seen based on the overall and average MAPE value of the forecasting results in five time ranges. The EEMD-ARIMA method has an average MAPE value of 9.09% and standard deviation MAPE value of 7.39%. OPEC crude oil price forecast in January-August 2021 ranges from 42.22 to 60.6 USD per barrel. The final result of the analysis in this study shows that the ARIMA method with decomposition data (EEMD-ARIMA) is better than the ARIMA method using original data.
Keyword: ARIMA, EEMD, EMD, forecast, OPEC crude oil price

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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