Country size and ‘insulation’ from external disturbances

Summary This paper considers the relationship between economic size and vulnerability to external disturbances. In order to analyze this issue effectively a model comprising three different-sized economies is constructed. The issue of economic size and insulation is approached from this alternative perspectives depending upon the relative size of (a) the `recipient' country and (b) the transmitting country. The results of the analysis indicate that, contrary to popular belief, a small country under floating exchange rates is less severely affected by external economic events than a large economy regardless of the type of external disturbance and the degree of domestic wage indexation.This paper has been improved by the helpful comments of a referee. We alone are solely responsible for all remaining errors.     

Pricing Decisions in Dual-Channel Supply Chain Including Monopolistic Manufacturer and Duopolistic Retailers: A Game-Theoretic Approach

Emergence of the Internet as a new distribution channel has led to increasing attention by researchers to dual-channel supply chain in recent years. In this paper, pricing and ordering decisions are investigated on a dual-channel supply chain which consists of monopolistic manufacturer and duopolistic retailers. The market is assumed to be controlled by the manufacturer. Thus, the manufacturer becomes leader and the two retailers act as followers. Due to establishing this new structure, different game-theoretic models including Bertrand, Collusion, and Stackelberg are developed to analyze pricing strategies under the various interactions between the two retailers. Then, the equilibrium decisions are compared under the considered scenarios and valuable managerial insights are presented. We found that the various games do not have any effects on the manufacturer’s responses. The retail prices given by the Collusion game are higher than by the other games. In the Collusion model, demands in the retail channel are lower than in the other games. Moreover, the manufacturer and retailers receive respectively the lowest and the highest profits under the Collusion game.     

Reservoir volume optimization and performance evaluation of rooftop catchment systems in arid regions: A case study of Birjand,Iran

This study evaluated the performance of rooftop catchment systems in securing non-potable water supply in Birjand, located in an arid area in southeastern Iran. The rooftop catchment systems at seven study sites of different residential buildings were simulated for dry, normal, and wet water years, using 31-year rainfall records. The trial and error approach and mass diagram method were employed to optimize the volume of reservoirs in five different operation scenarios. Results showed that, during the dry water year from 2000 to 2001, for reservoirs with volumes of 200–20000 L, the proportion of days that could be secured for non-portable water supply was on average computed to be 16.4%–32.6% across all study sites. During the normal water year from 2009 to 2010 and the wet water year from 1995 to 1996, for reservoirs with volumes of 200–20000 L, the proportions were 20.8%–69.6% and 26.8%–80.3%, respectively. Therefore, a rooftop catchment system showed a high potential to meet a significant portion of non-potable water demand in the Birjand climatic region. Reservoir volume optimization using the mass diagram method produced results consistent with those obtained with the trial and error approach, except at sites #1, #2, and #5. At these sites, the trial and error approach performed better than the mass diagram method due to relatively high water consumption. It is concluded that the rooftop catchment system is applicable under the same climatic conditions as the study area, and it can be used as a drought mitigation strategy as well.     

ADVERSE SELECTION WITH HETEROGENEOUSLY INFORMED AGENTS

A model of over-the-counter markets is proposed. Some asset buyers are informed in that they can identify high-quality assets. Sellers with private information choose what type of buyers they want to trade with. When the measure of informed buyers is low, a unique equilibrium exists, and interestingly, price, trading volume and welfare typically decrease with more informed buyers. When the measure of informed buyers is intermediate, multiple equilibria arise. A switch from one equilibrium to another can lead to large drops in liquidity, price, trading volume, and welfare, like a financial crisis. Implications of an endogenous measure of informed buyers are also studied.     

Injuries and their burden in insured construction workers in Iran, 2012

The present study used disability adjusted life years (DALY) to estimate the burden of external cause of injuries in construction workers insured in Iran in 2012. The Global Burden of Disease method (2010) was used to estimate the years of life lost due to death (YLL) and years of life lost due to disability (YLD). DALY was calculated as the sum of YLL and YLD. There were 5352 injured construction workers in Iran (11.25 individuals per 1000). Falling was the most common incidence and included 2490 individuals (46.53%). Totally, DALY was estimated 18,557 years for all age groups and both genders including 17,821 YLD (96%) and 736 YLL (4%). The DALY related to construction work is high in Iran and it has notably affected the young. Hence more preventive methods should be applied to reduce the overall burden of specific external cause of injuries especially in young and inexperienced workers.     

Home-related injuries among under-five-year children and mothers' care regarding injury prevention in rural areas

This cross-sectional study was conducted in rural areas of Twiserkan (Toyserkan) County, in Iran, to assess factors associated with home-related injuries among under-five-year children and their mothers’ care regarding injury prevention. Mothers who had their under-five-year-old children injured within a 12-month period were identified from recorded information in Twiserkan Health Center. Then, data were gathered using pre-tested questionnaire and through interview with injured children's mothers. The questions were about characteristics of the children's injuries and their mothers’ care regarding injury prevention, using PRECEDE (Predisposing, Reinforcing, and Enabling Constructs in Educational/Environmental Diagnosis and Evaluation) model with focus on knowledge and attitude; enabling and reinforcing factors; and mothers' preventive behaviours. The study results showed that 197 out of 210 total identified mothers took part in the study. The reported injuries were 11.68%, 39.09%, and 49.24%, respectively, for severe, moderate, and mild cases. Fall was the most frequent injury with 35%. Among PRECEDE model constructs, there was a statistically significant correlation between mothers' knowledge and injury severity among children. Home-related injuries are an important health problem among study population and their prediction and prevention are necessary. Enhancement of mothers’ knowledge can be helpful to improve child injury prevention.     

Modeling hazardous materials risks for different train make-up plans

This paper is concerned with the problem of how to place hazardous material cars in the train assembly process so that the overall derailment risk can be minimized. The approach considers both the probability of railway cars derailing en route by position as well as the risk associated with additional operations in the rail yard using recent US FRA data. The merits of this car placement model are illustrated through a case study of a railway corridor that connects Los Angeles (CA) to Chicago (IL). The case study demonstrates that the proposed risk minimization strategy could be implemented with minimal rail yard operation cost.     

Improving Rainfall Forecasting Efficiency Using Modified Adaptive Neuro-Fuzzy Inference System (MANFIS)

Rainfall is one of the most complicated effective hydrologic processes in runoff prediction and water management. The adaptive neuro-fuzzy inference system (ANFIS) has been widely used for modeling different kinds of nonlinear systems including rainfall forecasting. Adaptive Neuro-Fuzzy Inference Systems (ANFIS) combines the capabilities of Artificial Neural Networks (ANN) and Fuzzy Inference Systems (FIS) to solve different kinds of problems, especially efficient in rainfall prediction. This paper after reconsidering conventional ANFIS architecture brings up a modified ANFlS (MANFlS) structure developed with attention to making ANFIS technique more efficient regarding to Root Mean Square Error (RMSE), Correlation Coefficient (R ²), Root Mean Absolute Error (RMAE), Signal to Noise Ratio (SNR) and computing epoch. The modified ANFIS (MANFIS) architecture is simpler than conventional ANFIS with nearly the same performance for modeling nonlinear systems. In this study, two scenarios were introduced; in the first scenario, monthly rainfall was used solely as an input in different time delays from the time (t) to the time (t-4) to conventional ANFIS, second scenario used the modified ANFIS to improve the rainfall forecasting efficiency. The result showed that the model based Modified ANFIS performed higher rainfall forecasting accuracy; low errors and lower computational complexity (total number of fitting parameters and convergence epochs) compared with the conventional ANFIS model.     

Application of ANFIS to exchange rate forecasting

The need of exchange rate forecasting in order to preventing its disruptive movements has engrossed many policy-makers and economists for many years. The determinants of exchange rate have grown manifold making its behavior complex, nonlinear and volatile so that nonlinear models have better performance for its forecasting. In this study the accuracy of ANFIS as the nonlinear model and ARIMA as the linear models for forecasting 2, 4 and 8 days ahead of daily Iran Rial/∈ and Rial/US$ was compared. Using forecast evaluation criteria we found that nonlinear model outperforms linear model in all three horizons.