The condition number for circulant networks

In this paper we prove that it is possible to use techniques specific to electromagnetic field synthesis in the study of some electrical circuits. The definition of a circulant network will be presented. The system matrix of such a network is a circular matrix, which allows an analytical evaluation of all the eigenvalues and all the singular values. Resonance frequencies can then be calculated exactly as will be demonstrated on passive and active circulant networks

Globalization and Urban-Rural Migration in Taiwan

In this study, we examine the association of urban-to-rural migration with the deterioration of labor market in urban sector due to the globalization of markets and production. Two measures of the relative impacts of globalization on urban and rural labor markets: changes in rural-urban real earning differential and changes in the rural-urban probabilities of being employed. We, thus, address the following questions. What would be the changes in both rural-urban real earning differential and the rural-urban differential in the probabilities of being employed over the last decade? Can real earning differentials or employment differentials, or both significantly influence the urban-to-rural migration decisions? Which one plays a pivotal role in the analysis? What would be the roles of individual or family characteristics in determining the urban-to-rural migration decisions? The preliminary results show the following implications. First of all, the increasing the probabilities of getting a job in rural sector versus keeping a job in urban sector play a pivotal role in determining the urban-to-rural migration. As employment opportunities became persistently worsen in urban sector, job security in rural became attractive and play a more important role than real earning differential. Secondly, having a family member working in rural sector significantly influences the urban-to-rural migration.globalization, labor migration, agricultural sector, Community/Rural/Urban Development, J31, I20,

Green's functions of potential problems in lens shaped geometries

The Kelvin inversion method will be outlined to determine the potential distribution due to a point charge (or the Green's function) in geometries bounded by flat and spherical surfaces

Use of sigma factor M from Bacillus subtilis in the development of an orthogonal expression system in Escherichia coli

Background: Technological advances in synthetic biology, systems biology, and metabolic engineering have boosted applications of industrial biotechnology for an increasing number of complex and high added-value molecules. In general, the transfer of multi- gene or poorly understood heterologous pathways into the production host leads to imbalances due to lack of adequate regulatory mechanisms. Hence, fine-tuning expression of synthesis pathways in specific conditions is mandatory. Objectives: Here we develop a new genetic circuit for regulated expression specifically in stationary phase due to clear advantages during this period (reduction of toxicity, competition). Methods: This circuit consists of a heterologous sigma factor () recognizing specific promoter sequences, which are not recognised by the native factors of E. coli and is expressed upon entering the stationary phase. First, several factors of B. subtilis were tested for their orthogonality in E. coli on the level of promoter recognition, by using a red-fluorescent reporter system. Secondly, the potential of factors of B. subtilis to work together with the E. coli core RNA polymerase was tested, by expressing these proteins together with their promoters. Based on the results a specific factor will be chosen for further optimalisation and the corresponding gene can be cloned in the S factor operon of E. coli, which is most abundantly expressed in stationary conditions. Conclusions: Combining all these elements should allow us to create an orthogonal genetic circuit that is able to transcribe specific genes under stationary phase with a limited influence on the host cell’s metabolism

Unstable inverse heat transfer problems in microelectronics

Inverse heat transfer problems are very important for the thermal testability of integrated circuits. Temperature sensors integrated on the same chip measure in real time the power dissipation in one or more critical heat sources of the circuit in order to prevent overheating. It will be demonstrated that these kinds of problems can give rise to mathematical unstabilities or the ill conditioning of the inverse problem. This statement will be proved with the help of several particular cases

Do private sustainability standards contribute to income growth and poverty alleviation? : a comparison of different coffee certification schemes in Ethiopia

Private sustainability standards are increasingly important in food trade with developing countries, but the implications for smallholder farmers are still poorly understood. We analyze the implications of different coffee certification schemes in Ethiopia using cross-sectional survey data, and regression and propensity-score-matching techniques. We find that: Rainforest Alliance (RA) and double Fairtrade-Organic (FT-Org) certifications are associated with higher incomes and reduced poverty, mainly because of higher prices; Fairtrade (FT) certification hardly affects welfare; and Organic (Org) certification reduces incomes, chiefly due to lower yields. Cooperative heterogeneity importantly shapes these results. Results imply that private standards may not always deliver what they promise to consumers