Quantum annealing for vehicle routing and scheduling problems

Metaheuristic approaches to solving combinatorial optimization problems have many attractions. They sidestep the issue of combinatorial explosion; they return good results; they are often conceptually simple and straight forward to implement. There are also shortcomings. Optimal solutions are not guaranteed; choosing the metaheuristic which best fits a problem is a matter of experimentation; and conceptual differences between metaheuristics make absolute comparisons of performance difficult. There is also the difficulty of configuration of the algorithm - the process of identifying precise values for the parameters which control the optimization process. Quantum annealing is a metaheuristic which is the quantum counterpart of the well known classical Simulated Annealing algorithm for combinatorial optimization problems. This research investigates the application of quantum annealing to the Vehicle Routing Problem, a difficult problem of practical significance within industries such as logistics and workforce scheduling. The work devises spin encoding schemes for routing and scheduling problem domains, enabling an effective quantum annealing algorithm which locates new solutions to widely used benchmarks. The performance of the metaheuristic is further improved by the development of an enhanced tuning approach using fitness clouds as behaviour models. The algorithm is shown to be further enhanced by taking advantage of multiprocessor environments, using threading techniques to parallelize the optimization workload. The work also shows quantum annealing applied successfully in an industrial setting to generate solutions to complex scheduling problems, results which created extra savings over an incumbent optimization technique. Components of the intellectual property rendered in this latter effort went on to secure a patent-protected status

Assets of Cyprus Households: Lessons from the First Cyprus Survey of Consumer Finances

This paper describes participation of Cyprus households in financial and real assets using new data from the 1999 Cyprus Survey of Consumer Finances, and compares Cyprus to the United States and four major European countries. Almost 9 out of 10 Cyprus households own some financial asset. After checking accounts, the most popular financial asset is government savings bonds. One in two households participated in stocks directly or indirectly in 1999, a year of stock market frenzy, reaching participation levels comparable only to the United States. Despite the absence of mutual funds, almost one third of households invest in managed portfolios linked to life insurance, and this exceeds direct stockholding even in 1999. Participation in direct stockholding is higher than in other countries, overall and for households below 50 years, and unusually high for the very young. Potential sources of concern include the limited number of stocks held by direct stockholders, and the presence of a significant contingent with limited background. Diversification across risk categories of financial assets is limited, but the majority of those holding few assets do not hold stocks directly. Those who do hold stocks directly are poorly diversified across different stocks. More than one in two households have some form of life insurance, but participation in individual retirement accounts is very low. Participation in risky assets, financial or real, far exceeds that in other countries. Yet, a strong contingent of households concentrates on risky real assets and abstains from risky financial assets, even during 1999. Rates of ownership of real assets are exceptionally high compared to the other countries. Homeownership rates far exceed those in the United States, and the majority of homeowners own their home fully. One quarter of Cyprus households own business equity, more than double the rate in the United States.

Debts of Cyprus Households: Lessons from the First Cyprus Survey of Consumer Finances

This paper describes the participation of Cyprus households in various types of debt using data from the first (1999) Cyprus Survey of Consumer Finances. It complements the 2001 paper by Haliassos et al. The findings are of interest to policy makers, as they show the extent of household participation in various loans and the indebtedness of various demographic groups. We document the considerable popularity of credit cards as borrowing instruments and a continuing parallel presence of antiquated forms of borrowing. There is surprisingly limited use by the young of mortgages, despite very high home ownership rates, and of car loans, despite high car ownership rates. We find evidence of a strong reliance on family transfers for the financing of higher education, home acquisitions and car purchases by the young. Finally, we note a tendency for Cypriot entrepreneurs to take out large loans from their business for personal use.

Debts of Cyprus Households: Lessons from the First Cyprus Survey of Consumer Finances

This paper describes participation of Cyprus households in various debts using data from the first (1999) Cyprus Survey of Consumer Finances. It complements our previous paper that described household participation in various types of assets (Haliassos et al., 2001). Debts considered encompass personal unsecured loans, including credit card debt, and loans secured by housing collateral, mainly mortgage debt. Findings are of policy interest, as they show the extent of household participation in various loans, and the indebtedness of various demographic groups. We document considerable popularity of credit cards as borrowing instruments despite their recent introduction, and a continuing parallel presence of antiquated forms of borrowing (informal store credits). There is surprisingly limited use by the young of mortgages, despite very high homeownership rates, and of car loans, despite high car ownership rates. We find evidence of considerable reliance on family transfers for the financing of education, home acquisition, and car purchase by the young. Particularly problematic for equality of opportunities is the limited ability of the young to take student loans and the reliance on their parents to do so in order to finance their post-secondary education. Finally, we have noted a tendency of Cyprus business owners to take out large loans from their business for personal use.

Assets of Cyprus Households: Lessons from the first Cyprus Survey of Consumer Finances

This paper describes participation of Cyprus households in financial and real assets using new data from the 1999 Cyprus Survey of Consumer Finances, and compares Cyprus to the United States and four major European countries. Almost 9 out of 10 Cyprus households own some financial asset. After checking accounts, the most popular financial asset is government savings bonds. One in two households participated in stocks directly or indirectly in 1999, a year of stock market frenzy, reaching participation levels comparable only to the United States. Despite the absence of mutual funds, almost one third of households invest in managed portfolios linked to life insurance, and this exceeds direct stockholding even in 1999. Participation in direct stockholding is higher than in other countries, overall and for households below 50 years, and unusually high for the very young. Potential sources of concern include the limited number of stocks held by direct stockholders, and the presence of a significant contingent with limited background. Diversification across risk categories of financial assets is limited, but the majority of those holding few assets do not hold stocks directly. Those who do hold stocks directly are poorly diversified across different stocks. More than one in two households have some form of life insurance, but participation in individual retirement accounts is very low. Participation in risky assets, financial or real, far exceeds that in other countries. Yet, a strong contingent of households concentrates on risky real assets and abstains from risky financial assets, even during 1999. Rates of ownership of real assets are exceptionally high compared to the other countries. Homeownership rates far exceed those in the United States, and the majority of homeowners own their home fully. One quarter of Cyprus households own business equity, more than double the rate in the United States.

Debts Of Cyprus Households: Lessons From The First Cyprus Survey Of Consumer Finances

This paper describes participation of Cyprus households in various debts using data from the first (1999) Cyprus Survey of Consumer Finances. It complements our previous paper that described household participation in various types of assets (Haliassos et al., 2001). Debts considered encompass personal unsecured loans, including credit card debt, and loans secured by housing collateral, mainly mortgage debt. Findings are of policy interest, as they show the extent of household participation in various loans, and the indebtedness of various demographic groups. We document considerable popularity of credit cards as borrowing instruments despite their recent introduction, and a continuing parallel presence of antiquated forms of borrowing (informal store credits). There is surprisingly limited use by the young of mortgages, despite very high homeownership rates, and of car loans, despite high car ownership rates. We find evidence of considerable reliance on family transfers for the financing of education, home acquisition, and car purchase by the young. Particularly problematic for equality of opportunities is the limited ability of the young to take student loans and the reliance on their parents to do so in order to finance their post-secondary education. Finally, we have noted a tendency of Cyprus business owners to take out large loans from their business for personal use