Judul: The influence of international soybean price shock on domestic soybean price
Abstrak: Foods are primary human basic need. Lack of food supply could implicate on social and politic instability. The fluctuation of foods prices influence risk and uncertainty on decision making process. Soybean is primary commodity in Indonesia after rice and corn. The growth of soybean production is lower than its demand so it leads to increasing number of import. High number of imported soybean may indicate a correlation between international and domestic soybean price. The objectives of this study are (1) to analyze the short term correlation between international soybean price and domestic soybean price, (2) to analyze the long term correlation between international soybean price and domestic soybean price, and (3) to determine the impact of international soybean price shock on domestic soybean price. This study used data from Ministry of Trade, Bank of Indonesia (BI), United States Departement of Agriculture (USDA) and Zhengzhou Commodity Exchange (CZCE). International soybean price represented by USA soybean price (world largest exporter) and China soybean price (world largest importer). Those data above were secondary data in monthly time series form collected from 2009 until 2012. The method use in this study is Vector Correction Error Model (IRF, FEVD and pass trough). This study use Eviews 6.0 software. Study show that in the short term, international soybean price (USA and China) influence’s to domestic soybean price were not significant. In long term the USA soybean price has positive significant influence to domestic soybean prices. In contrast, the real exchange rate has negative significant influence. Pass trough analysis conclude that the impact of international soybean price (USA soybean price) shock on domestic soybean price was 1.6 percent.
Keyword: VECM, international soybean price, domestic soybean price

Judul: Soybean Price Volatility Analysis in Indonesia
Abstrak: Kedelai merupakan komoditas pangan utama selain padi dan jagung yang berfungsi sebagai sumber protein nabati masyarakat Indonesia. Fluktuasi perubahan varians harga akan menyebabkan volatilitas harga dan berdampak pada industri olahan pangan, salah satunya adalah industri tahu dan tempe yang merupakan industri kecil dengan modal yang terbatas. Oleh karena itu, stabilitas harga kedelai perlu dilakukan antisipasi oleh pemerintah untuk meminimalisir resiko dan ketidakpastian yang akan merugikan baik produsen maupun konsumen kedelai. Penelitian ini bertujuan untuk menganalisis volatilitas harga kedelai baik kedelai lokal tingkat konsumen maupun produsen dan kedelai impor, serta harga tahu dan tempe di Indonesia. Penelitian menggunakan data time series bulanan dari Januari 2010 sampai Desember 2021. Metode yang digunakan adalah ARCHGARCH untuk menghitung besaran volatilitas dari variabel harga kedelai baik kedelai lokal tingkat konsumen maupun produsen dan kedelai impor, serta harga tahu dan tempe di Indonesia. Hasil penelitian menunjukkan harga konsumen kedelai lokal lebih volatil dibandingkan harga kedelai impor. Harga kedelai tingkat produsen dan harga tempe menunjukkan tingkat volatilitas yang rendah sementara harga tahu menunjukkan tingkat volatilitas yang tinggi yang akan berpengaruh besar terhadap dinamika pasar., Soybean is the main food commodity besides rice and corn which functions as a source of vegetable protein for the Indonesian people. Fluctuations in price variance will cause price volatility and have an impact on the food processing industry, one of which is the tofu and tempeh industry, which is a small industry with limited capital.. Therefore, it is necessary to anticipate the stability of soybean prices the government to minimize risks and uncertainties that will harm both soybean producers and consumers. This study aims to analyze the volatility of soybean prices, both local consumer and producer level soybeans and imported soybeans, as well as tofu and tempeh prices in Indonesia. The study uses monthly time series data from January 2010 to December 2021. The method used is ARCH-GARCH to calculate the volatility of soybean price variables, both local soybeans at consumer and producer levels and imported soybeans, as well as prices of tofu and tempeh in Indonesia. The results showed that local soybean consumer prices were more volatile than imported soybean prices. Soybean prices at the producer level and tempeh prices show a low level of volatility, while tofu prices show a high level of volatility which will have a major influence on market dynamics. Keywords: ARCH-GARCH model, Indonesian soybean price, Volatility
Keyword: ARCH-GARCH model, Indonesian soybean price, Volatility

Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf