Spending and Growth: A Modified Debt to GDP Dynamic Model

The paper addresses a topical issue – how expansionary fiscal policy affects the debt to GDP ratio. It examines whether the projected future economic growth (stimulated by government spending) is sustained with the resulting national debt. It is discussedif government investment in infrastructure is an effective approach to boost the economy in times of economic downturn. The authors develop the debt to GDP ratio dynamics model and perform a series of simulations (based on US data) to forecast the evolution of the debt to GDP ratio over a 10-year horizon. It is shown that for the data characterizing the current state of the U.S. economy the government investment in infrastructure cannot decrease the debt to GDP ratio

Control Architecture and Simulation of the Borea Quadrotor

The paper presents modelling, control design and simulated results preliminary to test the Borea quadrotor. Guidance, navigation and control strategy are implemented following the Embedded Model Control (EMC) schem

Hybrid Genetic Bees Algorithm applied to Single Machine Scheduling with Earliness and Tardiness Penalties

This paper presents a hybrid Genetic-Bees Algorithm based optimised solution for the single machine scheduling problem. The enhancement of the Bees Algorithm (BA) is conducted using the Genetic Algorithm's (GA's) operators during the global search stage. The proposed enhancement aims to increase the global search capability of the BA gradually with new additions. Although the BA has very successful implementations on various type of optimisation problems, it has found that the algorithm suffers from weak global search ability which increases the computational complexities on NP-hard type optimisation problems e.g. combinatorial/permutational type optimisation problems. This weakness occurs due to using a simple global random search operation during the search process. To reinforce the global search process in the BA, the proposed enhancement is utilised to increase exploration capability by expanding the number of fittest solutions through the genetical variations of promising solutions. The hybridisation process is realised by including two strategies into the basic BA, named as â\u80\u9creinforced global searchâ\u80\u9d and â\u80\u9cjumping functionâ\u80\u9d strategies. The reinforced global search strategy is the first stage of the hybridisation process and contains the mutation operator of the GA. The second strategy, jumping function strategy, consists of four GA operators as single point crossover, multipoint crossover, mutation and randomisation. To demonstrate the strength of the proposed solution, several experiments were carried out on 280 well-known single machine benchmark instances, and the results are presented by comparing to other well-known heuristic algorithms. According to the experiments, the proposed enhancements provides better capability to basic BA to jump from local minima, and GBA performed better compared to BA in terms of convergence and the quality of results. The convergence time reduced about 60% with about 30% better results for highly constrained jobs

What is Behind the High Dental Costs in the U.S.

Healthcare is among the most important issues for Americans since the U.S. health care system is the most expensive in the world. Analyzing the U.S. rising cost of health care in the 21 century it is impossible not to see that the increase of dental prices exceeds significantly the growth of prices for many other medical services. Regular preventive dental care is essential for good oral health, but many persons don’t get the care they need. More people are unable to afford dental care than other types of health care. Such situation with dental health is inadmissible.</jats:p