This paper proposes optimization models of crude oil distillation column for both limited and unlimited feed stock and market value of known products prices. The feed to the crude distillation column was assumed to be...This paper proposes optimization models of crude oil distillation column for both limited and unlimited feed stock and market value of known products prices. The feed to the crude distillation column was assumed to be crude oil containing naphtha gas, kerosene, petrol and diesel as the light-light key, light key, heavy key and heavy-heavy key respectively. The models determined maximum concentrations of heavy key in the distillate and light key in the bottom for limited feed stock and market condition. Both were impurities in their respective positions of the column. The limiting constraints were sales specification concentration of light key in the distillate [ ], heavy key in the bottom [ ] and an operating loading constraint of flooding above the feed tray. For unlimited feed stock and market condition, the optimization models determined the optimum separation [ and ] and feed flow rate that would give maximum profit with minimum purity sales specification constraints of light key in the distillate and heavy key in the bottom as stated above. The feed loading was limited by the reboiler capacity. However, there is need to simulate the optimization models for an existing crude oil distillation column of a refinery in order to validate the models.展开更多
Stocking of Lake Kinneret by exotic fish species (Mugilids: Mugil cephalus and Liza ramada) started in 1958. The rational stocking of Lake Kinneret with Mugilids was double functioned: To improve fishermen income and ...Stocking of Lake Kinneret by exotic fish species (Mugilids: Mugil cephalus and Liza ramada) started in 1958. The rational stocking of Lake Kinneret with Mugilids was double functioned: To improve fishermen income and the water quality in the lake. Mugilids are chosen as introduction target because their market value is high, the fish cannot reproduce in the lake and fingerlings are low cost available. During 1960-2015, 56.2 million fingerlings were introduced into the lake approximately averaged one million per year of M. cephalus (MC) and L. ramada (LR). The study of the Mugilids food composition has indicated consumption of suspensoids, mostly detritial organic particles. Therefore no damage to water quality is suggested. The best fitness between recruitment to Dock on Side landings and stocking capacity was evaluated at 3 years interval. Differences were found between recruitments of MC and LR to commercial catches by individual averaged age and weight. The long term success of Mugilid introduction to Lake Kinneret is confirmed.展开更多
Use of artificial neural networks has become a significant and an emerging research method due to its capability of capturing nonlinear behavior instead of conventional time series methods. Among them, feed forward ba...Use of artificial neural networks has become a significant and an emerging research method due to its capability of capturing nonlinear behavior instead of conventional time series methods. Among them, feed forward back propagation neural network (BPNN) is the widely used network topology for forecasting stock prices indices. In this study, we attempted to find the best network topology for one step ahead forecasting of All Share Price Index (ASPI), Colombo Stock Exchange (CSE) by employing feed forward BPNN. The daily data including ASPI, All Share Total Return Index (ASTRI), Market Price Earnings Ratio (PER), and Market Price to Book Value (PBV) were collected from CSE over the period from January 2nd 2012 to March 20th 2014. The experiment is implemented by prioritizing the number of inputs, learning rate, number of hidden layer neurons, and the number of training sessions. Eight models were selected on basis of input data and the number of training sessions. Then the best model was used for forecasting next trading day ASPI value. Empirical result reveals that the proposed model can be used as an approximation method to obtain next day value. In addition, it showed that the number of inputs, number of hidden layer neurons and the training times are significant factors that can be affected to the accuracy of forecast value.展开更多
文摘This paper proposes optimization models of crude oil distillation column for both limited and unlimited feed stock and market value of known products prices. The feed to the crude distillation column was assumed to be crude oil containing naphtha gas, kerosene, petrol and diesel as the light-light key, light key, heavy key and heavy-heavy key respectively. The models determined maximum concentrations of heavy key in the distillate and light key in the bottom for limited feed stock and market condition. Both were impurities in their respective positions of the column. The limiting constraints were sales specification concentration of light key in the distillate [ ], heavy key in the bottom [ ] and an operating loading constraint of flooding above the feed tray. For unlimited feed stock and market condition, the optimization models determined the optimum separation [ and ] and feed flow rate that would give maximum profit with minimum purity sales specification constraints of light key in the distillate and heavy key in the bottom as stated above. The feed loading was limited by the reboiler capacity. However, there is need to simulate the optimization models for an existing crude oil distillation column of a refinery in order to validate the models.
文摘Stocking of Lake Kinneret by exotic fish species (Mugilids: Mugil cephalus and Liza ramada) started in 1958. The rational stocking of Lake Kinneret with Mugilids was double functioned: To improve fishermen income and the water quality in the lake. Mugilids are chosen as introduction target because their market value is high, the fish cannot reproduce in the lake and fingerlings are low cost available. During 1960-2015, 56.2 million fingerlings were introduced into the lake approximately averaged one million per year of M. cephalus (MC) and L. ramada (LR). The study of the Mugilids food composition has indicated consumption of suspensoids, mostly detritial organic particles. Therefore no damage to water quality is suggested. The best fitness between recruitment to Dock on Side landings and stocking capacity was evaluated at 3 years interval. Differences were found between recruitments of MC and LR to commercial catches by individual averaged age and weight. The long term success of Mugilid introduction to Lake Kinneret is confirmed.
文摘Use of artificial neural networks has become a significant and an emerging research method due to its capability of capturing nonlinear behavior instead of conventional time series methods. Among them, feed forward back propagation neural network (BPNN) is the widely used network topology for forecasting stock prices indices. In this study, we attempted to find the best network topology for one step ahead forecasting of All Share Price Index (ASPI), Colombo Stock Exchange (CSE) by employing feed forward BPNN. The daily data including ASPI, All Share Total Return Index (ASTRI), Market Price Earnings Ratio (PER), and Market Price to Book Value (PBV) were collected from CSE over the period from January 2nd 2012 to March 20th 2014. The experiment is implemented by prioritizing the number of inputs, learning rate, number of hidden layer neurons, and the number of training sessions. Eight models were selected on basis of input data and the number of training sessions. Then the best model was used for forecasting next trading day ASPI value. Empirical result reveals that the proposed model can be used as an approximation method to obtain next day value. In addition, it showed that the number of inputs, number of hidden layer neurons and the training times are significant factors that can be affected to the accuracy of forecast value.
