Balibey, Mesut; Akdi, Yilmaz

Bu çalışmada Türkiye ekonomisindeki 02.01.2013 ile 11.12.2018 dönemi günlük (5 işgünü) döviz kurlarındaki döngüler, periodogramlar yardımıyla belirlenmeye çalışılmıştır.Çalışmada günlük Türk lirası karşısında Dolar kapanış (Xt) ve Euro kapanış (Yt) değerleridikkate alınmıştır. Analizler sonucunda bu iki serinin de aynı periyodlarda hareket ettiğigözlenmiştir. Günlük döviz kurlarının durağanlığı standart birim kök testlerinin yanındaperiodogram tabanlı birim kök testi ile de sınanmış ve her iki serinin de birinci derecedenbütünleşik olduğu gözlenmiştir. Birinci derece fark serilerinde 4, 6 ve 7 günlük periyodlargözlenmiştir.

İncele

Zengin, Ersoy

Ergani Copper Mine Imperial is the most important copper mine of Ottoman Empire. The ownership of this mine belonged to the state and the operation was given to private individuals (taxman). Taxman used to sell raw copper he obtained after mining and various refining processes to the government with a price determined by the government. Those coppers bought from the taxman were used to supply needs of government enterprises such as arm and ship factories, and the rest was sold abroad. As well as providing income by selling copper abroad, copper production called for struggling with specific problems. One of them was the shipment of copper to Iskenderun and Samsun harbours. Another one was the supply of wood coal necessary for refining the copper. Another problem was activating the modern technology which would enable production at a lower cost. It was necessary to build railway in the region for solving the first two of the problems. Yet, it was not possible to carry out things, which required great capital, such as building railway without foreign capital.

AtıfTR Dizin1

İncele

Yucesan, Melih

In this study, hybrid ARIMAX-ANN and SARIMAX-ANN sales forecasting modelsare proposed for a white goods wholesaler. White goods industry which is one of the durable goodssub-sector includes washing machines, dishwashers, refrigerators and small home appliances. Inmaking forecasts, 46-month sales data of a white goods wholesaler are used. Factors influencingsales such as exchange rate, holidays, consumer confidence index (CCI), producer price index(PPI) and residential sales of the region are used as explanatory variables. The study contributesto the current literature by some aspects. First, there is no attempts applying the ARIMAX-ANNand SARIMAX-ANN hybrid models to forecast sales data in white goods industry. Second, thehybrid models combine the advantages of times series and ANN models. ARIMAX models areinsufficient to solve complex nonlinear problems. On the other hand, ANN is sufficient to explainnonlinear relationships. On conclusion, use of hybrid models can increase the accuracy of themodels.

İncele