this study was conducted to investigate hematophagic tendencies of the malaria vector based on a seasonal basis as well as by geographical region in a malaria endemic area in kahnouj, southern iran. this study was carried out for 14 months from apr/ 2002 up to the end of may 2003. female anophelines were collected from different shelters in hilly and plain regions of kahnouj district and their ...

abstract     the major constraints of agricultural production in the south western coastal areas of bangladesh are soil and water salinity of varying degrees, lack of fresh water for irrigation, slow soil drying pattern which are being augmented further due to climate change, requires suitable options of farming systems and component technologies. the major constraints and potentials of agricul...

In this paper we propose to apply wavelet theory in forecasting economic time series. The method consists in decomposing the series into its long-term trend and its seasonal component according to the shape of the scalogram of the discrete wavelet transform of the series. Each component is then extended to provide a forecast of the total series. The method is applied to the data set of monthly ...

In this paper, we develop an aggregation procedure using time-varying weights for constructing the common component of international economic fluctuations. The methodology for deriving time-varying weights is based on some stylised features of the data documented in the paper. The model allows for a unified treatment of cyclical and seasonal fluctuations and also accommodates the dynamic propag...

Time-series data on community structure in the upper 200 m at Station ALOHA in the subtropical North Pacific were collected at approximately monthly intervals from December 1990 through to March 1994 during an extended El Niño-Southern Oscillation (ENSO) event. Samples were analyzed by flow cytometry to enumerate Prochlorococcus, Synechococcus, picoeucaryotes, 3 20 μm algae, and heterotrophic b...

In this paper, we use neural networks in order to model the seasonal component of the residual variance of a mean-reverting Ornstein-Uhlenbeck temperature process, with seasonality in the level and volatility. We also use wavelet analysis to identify the seasonality component in the temperature process as well as in the volatility of the temperature anomalies. Our model is validated on more tha...

Consider the three-component time series model that decomposes observed data (Y ) into the sum of seasonal (S), trend (T ), and irregular (I) portions. Assuming that S and T are nonstationary and that I is stationary, it is demonstrated that widely-used Wiener-Kolmogorov signal extraction estimates of S and T can be obtained through an iteration scheme applied to optimal estimates derived from ...

Fuzzy time series forecasting methods do not require constraints found in conventional approaches. In addition, due to uncertainty that they contain, many time series to be forecasted should be considered as fuzzy time series. Fuzzy time series forecasting models consist of three steps as fuzzification, identification of fuzzy relations and defuzzification. Although most of the time series enco...

Migration is an important component of the life history of many animals, but persistence of large-scale terrestrial migrations is being challenged by environmental changes that fragment habitats and create obstacles to animal movements. In northern Alaska, the Central Arctic herd (CAH) of barren-ground caribou (Rangifer tarandus granti) is known to migrate over large distances, but the herd's s...