Judul: Analysis of Factors Affecting Price Fluctuations and Market Integration of Large Red Chili (Case Study: Kramat Jati Main Market and Retail Market in DKI Jakarta)
Abstrak: Fluktuasi harga pangan merupakan fenomena yang menjadi perhatian yang serius yang dapat memengaruhi tingkat inflasi. Salah satu kelompok sayuran yang menyumbang inflasi adalah cabai merah besar. Penelitian ini bertujuan untuk menganalisis pola perkembangan harga cabai merah besar di PIKJ dan di lima pasar eceran di DKI Jakarta, faktor – faktor yang memengaruhi flukuasi harga cabai merah besar di PIKJ, peramalan harga cabai merah besar di PIKJ tahun 2023, dan integrasi pasar antara pasar grosir dengan pasar eceran di DKI Jakarta. Metode yang digunakan adalah metode analisis deskriptif, OLS, ARIMA, dan VECM. Hasil penelitian menunjukkan bahwa: 1) pola perkembangan harga cabai merah besar di PIKJ dan di lima pasar eceran di DKI Jakarta memiliki pola yang berfluktuasi; 2) faktor – faktor yang berpengaruh nyata terhadap fluktuasi harga cabai merah besar di PIKJ adalah lag rata – rata harga cabai merah di PIKJ, rata – rata harga cabai merah keriting di PIKJ, dan ketersediaan stok cabai merah besar di PIKJ; 3) hasil peramalan harga cabai merah besar di PIKJ selama 8 bulan sebesar Rp29.858; 4) hasil integrasi pasar menunjukkan bahwa PIKJ memiliki keterkaitan jangka panjang antara Pasar Jatinegara, Pasar Minggu, dan Pasar Tanah Abang., Fluctuations in food prices are a phenomenon of serious concern that can affect the inflation rate. One group of vegetables contributing to inflation was large red chilies. This study aims to analyze the pattern of large red chili price developments in PIKJ and in five retail markets in DKI Jakarta, the factors that influence large red chili price fluctuations in PIKJ, forecasting large red chili prices in PIKJ in 2023, and market integration between markets. wholesaler with retail market in DKI Jakarta. The method used was descriptive analysis method, OLS, ARIMA, and VECM. The results showed that: 1) the pattern of large red chili prices at PIKJ and five retail markets in DKI Jakarta has a fluctuating pattern; 2) factors that have a significant effect on large red chili price fluctuations in PIKJ are the average lag of red chili prices in PIKJ, average curly red chili prices in PIKJ, and stock availability of large red chilies in PIKJ; 3) the result of forecasting the price of large red chili at PIKJ for 8 months is 29,858 IDR; 4) the results of market integration show that PIKJ has a long-term relationship between Jatinegara Market, Sunday Market, and Tanah Abang Market.
Keyword: ARIMA, Inflasi, OLS, Peramalan, VECM, ARIMA, Inflation, OLS, Forecasting, VECM

Judul: Price Volatility of Large Red Chili and Its Effect on
Inflation in DKI Jakarta and West Java
Abstrak: Tingginya permintaan dengan ketersediaan pasokan tidak berbanding lurus mengingat produksi cabai merah besar masih belum merata dan hanya difokuskan pada daerah tertentu yang menjadi sentra. Kondisi tersebut mendorong timbulnya karakteristik baru dari komoditas cabai merah besar yakni terjadinya volatilitas harga yang berpotensi mengakibatkan inflasi komponen bergejolak. Perbedaan tingkat produksi antara daerah sentra dan non sentra mengindikasikan adanya perbedaan pengaruh cabai merah besar terhadap nilai inflasi secara spasial. Metode analisis deskriptif dan kuantitatif yang digunakan pada penelitian ini terdiri dari analisis deskriptif untuk melihat disparitas harga, Coefficient of Variation untuk melihat fluktuasi harga, model ARCH/GARCH untuk menganalisis volatilitas harga, serta Error Correction Model untuk menganalisis pengaruh volatilitas harga cabai merah besar terhadap nilai inflasi di DKI Jakarta dan Jawa Barat. Hasil penelitian menunjukkan bahwa terjadi disparitas harga cabai merah besar di antara kedua provinsi tersebut dan harga cabai merah besar di DKI Jakarta lebih volatil dibandingkan dengan Jawa Barat. Volatilitas harga cabai merah besar berpengaruh signifikan terhadap nilai inflasi di DKI Jakarta pada jangka panjang dan pendek. Harga cabai keriting dan harga cabai rawit hijau berpengaruh signifikan terhadap nilai inflasi di Jawa Barat pada jangka pendek. Sementara itu, harga cabai keriting berpengaruh signifikan terhadap nilai inflasi di Jawa Barat pada jangka panjang., The high demand with the availability of supply is not directly proportional considering the production of large red chili is still uneven and only focused on certain areas that become centers. This condition encourages the emergence of new characteristics of chili commodities, such as price volatility, which has the potential to cause volatile component inflation. The differences in production levels between central and non-central areas indicate differences in the effects of large red chili on the inflation rate spatially. Descriptive and quantitative analysis methods used in this study consist of descriptive analysis to see price disparities, Coefficient of Variation to see price fluctuations, ARCH/GARCH models to analyze price volatility, and Error Correction Model to analyze the effect of large red chili price volatility on inflation rates in DKI Jakarta and West Java. The results show that there is a disparity in the price of red chili between the two provinces and the price of large red chili in DKI Jakarta is more volatile than West Java. Large red chili price volatility has a significant effect on the value of inflation in DKI Jakarta in the long and short term. The price of curly chili and the price of green cayenne pepper have a significant effect on the value of inflation in West Java in the short term. Meanwhile, the price of curly chili has a significant effect on the value of inflation in West Java in the long term.
Keyword: Inflasi, cabai merah besar, volatilitas harga, Inflation, large red chili, price volatility

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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