Parameterization of applied general equilibrium models with flexible trade specifications based on the Armington, Krugman, and Melitz models

This paper explains how the Armington-Krugman-Melitz supermodel developed by Dixon and Rimmer can be parameterized, and demonstrates that only two kinds of additional information are required in order to extend a standard trade model to include Melitz-type monopolistic competition and heterogeneous firms. Further, it is shown how specifying too much additional information leads to violations of the model constraints, necessitating adjustment and reconciliation of the data. Once a Melitz-type model is parameterized, a Krugman-type model can also be parameterized using the calibrated values in the Melitz-type model without any additional data. Sample code for the General Algebraic Modeling System (GAMS) has also been prepared to promote the innovative supermodel in the AGE community.

Impact of seasonality-adjusted flexible microcredit on repayment and food consumption : experimental evidence from rural Bangladesh

The mismatch between credit repayments and income seasonality poses a challenge for microfinance institutions (MFIs) working in developing countries. For instance, in northern Bangladesh, income and consumption downfalls during the lean season after the transplanting of major paddy crops are a serious threat to a household's economy. Poor landless agricultural wage laborers suffer the most owing to this seasonality as they face difficulties in smoothing their consumption. However, in designing microcredit products, MFIs do not usually provide flexibility or seasonal adjustment during the lean season. This is mainly because MFIs are afraid that such flexibility might break the repayment discipline of borrowers, resulting in higher default rates. We thus conducted a randomized controlled trial in 2011-12 in northern Bangladesh to empirically test whether seasonality-adjusted flexible microcredit leads to an increase in repayment problems for MFIs as well as whether it can increase and stabilize consumption of borrower households. Our results suggest no statistically discernible difference among the treatment arms in case of default, overdue amount, or repayment frequency. On the other hand, we find no positive impact of repayment flexibility on immediate food consumption during the period of seasonality, except for in-kind full moratorium treatment group. After a year of initial intervention, however, we see positive changes in food intake during the lean season. Thus, our preliminary results are in favor of seasonality-adjusted flexible microcredit.

n-Alkan-2-ones in peat-forming plants from the Roñanzas ombrotrophic bog (Asturias, northern Spain)

We determined the distribution of lipids (n-alkanes and n-alkan-2-ones) in present-day peat-formingplants in the RoñanzasBog in northernSpain. Consistent with the observation of others, most Sphagnum (moss) species alkanes maximized at C23, whereas the other plants maximized at higher molecular weight (C27 to C31). We show for the first time that plants other than seagrass and Sphagnum moss contain n-alkan-2-ones. Almost all the species analysed showed an n-alkan-2-one distribution between C21 and C31 with an odd/even predominance, maximizing at C27 or C29, except ferns, which maximized at lower molecular weight (C21–C23). We also observed that microbial degradation can be a major contributor to the n-alkan-2-one distribution in sediments as opposed to a direct input of ketones from plants

Eigenstructure Assignment Based Controllers Applied to Flexible Spacecraft

The objective of this paper is to evaluate the behaviour of a controller designed using a parametric Eigenstructure Assignment method and to evaluate its suitability for use in flexible spacecraft. The challenge of this objective lies in obtaining a suitable controller that is specifically designated to alleviate the deflections and vibrations suffered by external appendages in flexible spacecraft while performing attitude manoeuvres. One of the main problems in these vehicles is the mechanical cross-coupling that exists between the rigid and flexible parts of the spacecraft. Spacecraft with fine attitude pointing requirements need precise control of the mechanical coupling to avoid undesired attitude misalignment. In designing an attitude controller, it is necessary to consider the possible vibration of the solar panels and how it may influence the performance of the rest of the vehicle. The nonlinear mathematical model of a flexible spacecraft is considered a close approximation to the real system. During the process of controller evaluation, the design process has also been taken into account as a factor in assessing the robustness of the system.

Hacia una nueva vivienda social flexible mediante la investigación de procesos productivos industriales innovadores

En la siguiente comunicación se realiza una reflexión sobre el panorama actual de la construcción de vivienda de tipo social y la necesidad de un cambio a través de la transferencia e integración de metodología de producción industrial de otros sectores más evolucionados tecnológicamente que el sector de la construcción. El nuevo concepto de vivienda debe responder a unas características de funcionalidad, calidad y económicas ligadas a nuevos criterios de sostenibilidad, flexibilidad e industrialización. Se evalúan estos criterios para una posible adaptación a un nuevo concepto de vivienda teniendo en cuenta la adaptación de la producción a nuevos modelos de producción flexible desarrollados principalmente por industrias automovilísticas

6x3 Microstrip Beam Forming Network for Multibeam Triangular Array

A six inputs and three outputs structure which can be used to obtain six simultaneous beams with a triangular array of 3 elements is presented. The beam forming network is obtained combining balanced and unbalanced hybrid couplers and allows to obtain six main beams with sixty degrees of separation in azimuth direction. Simulations and measurements showing the performance of the array and other detailed results are presented

Robustness Analysis of Eigenstructure Assignment Controllers on Rigid-Flexible Satellites

Flexible spacecraft with attached solar panels may exhibit undesired vibrations and structural deformations. These types of vehicles show an intrinsic coupling of the elements of the structure. The attitude maneuvers performed by flexible spacecraft may cause non-desired deflections of attached flexible elements. Any attitude and orbit control system generally solves these problems using filters that are designed to attenuate the relative deflections of flexible appendages. In this paper, we propose a method for designing attitude static controllers using an eigenstructure assignment (EA) method. A set of requirements were specified from our understanding of the system modes in an open loop. Exhaustive theoretical and numerical simulations were performed on special cases to verify the controller design procedure. In the design of the controller, we considered all of the aspects that relate to the eigenstructure assignment. The primary objective of this paper is to demonstrate the feasibility of obtaining a high degree of decoupling for some selected modes via the application of an EA method. Finally a robustness analysis is perform to the system together with the designed controller by means of a mu-analysis

Airborne ultrasonic vortex generation using flexible ferroelectrets

Cellular ferroelectrets exhibit interesting electromechanical- acoustical characteristics. Their recent appearance and remarkable properties open up new possibilities for the design and development of ultrasonic transducers. In particular, the feasibility of fabricating ultrasonic vortex generators using ferroelectret films is demonstrated in this work. To this end, a transducer prototype was built by gluing the material onto a tangential-helical surface (outer diameter: 40 mm, pitch: 3.45 mm). Experimental results agree well with the theoretical estimation of the pressure and phase of the acoustic field in the near field and far field, which corroborates the potential of ferroelectrets to customize special acoustic fields. Furthermore, the proposed fabrication procedure is inexpensive and represents a new alternative for exploring and analyzing the special characteristics of acoustical helical wavefronts