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This article presents two lifetime models that describe two of the most common modes of operation of sensor nodes today, trigger-driven and duty-cycle driven. The models use a set of hardware parameters such as power consumption per task, state transition overheads, and communication cost to compute a node's average lifetime for a given event arrival rate. Through comparison of the two models and a case study from a real camera sensor node design we show how the models can be applied to drive architectural decisions, compute energy budgets and duty-cycles, and to preform side-by-side comparison of different platforms. Based on our models we present a MATLABWireless Sensor Node Platform Lifetime Prediction and Simulation Package (MATSNL). This demonstrates the use of the models using sample applications drawn from existing sensor node measurements. [ABSTRACT FROM AUTHOR]

This paper investigates the impact of human capital on the process of economic growth by allowing the contribution of traditional inputs (capital and labour) as well as that of human capital to vary both across countries and time. The former is accomplished by constructing an index of TFP growth for traditional inputs, while the latter through semiparametric methods. We derive estimates of the output elasticity and social return to human capital for 51 countries at various stages of economic development. Copyright © 2005 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Ad hoc localization of wireless sensor nodes is a fundamental problem in wireless sensor networks. Despite the recent proposals for the development of ad hoc localization algorithms, the fundamental behavior in systems using measurements has not been characterized. In this paper, we take a first step toward such a characterization by examining the behavior of error inducing parameters in multihop localization systems in an algorithm independent manner. We first derive the Cramé Rao Bound for Gaussian measurement error for multihop localization systems using distance and angular measurements. Later on, we use these bounds on a carefully controlled set of scenarios to study the trends in the error induced by the measurement technology accuracy, network density, beacon node concentration, and beacon uncertainty. By exposing these trends, the goal of this paper is to develop a fundamental understanding of the error behavior that can provide a set of guidelines to be considered during the design and deployment of multihop localization systems. [ABSTRACT FROM AUTHOR]

As cities are reaching critical densities of urban fabric, they face the dual problem of rising real estate values and vast areas of land in valuable locations occupied by highways and railways along with their supporting operations. Rights-of-way of both highways and railways, slicing through dense urban fabric, often act as barriers to growth. Further, they tend to generate edges which are problematic to use in positive ways and that physically delineate social separation. An answer to this phenomenon may be the joint development of air rights associated with urban transportation corridors by providing a means to reknit disrupted neighbourhoods and communities. [ABSTRACT FROM AUTHOR]

Estimates a stochastic production frontier and the sources of inefficiency to examine the impact of institutions on economic performance. Determinants of inefficiency; Translog production function.

In this paper we study the relationship between human capital accumulation and economic growth using various measures of human capital frequently employed by researchers. We use semiparametric estimation techniques to uncover any nonlinearities that may exist. Using mean years of schooling measures of human capital we find a nonlinear effect on economic growth. There seem to be important differences in the growth effect of educational attainment by gender and level of education. Enrollment rates do not yield a nonlinear effect. [ABSTRACT FROM AUTHOR]

Presents a study on the conduct and performance of monetary policy in five West and Central African countries. Identification of these countries; Exchange rate in these countries; Information on inflation, monetary independence and credit policy in these countries; Estimates of the offset coefficient and the conduct of monetary policy; Conclusions reached based on the study.

Focuses on the factors behind differences in per capita growth rates across Africa. Financial development; Political freedom and economic growth; Comparison between African counties; Empirical methodology for testing the determinants of growth across Africa.

Investigates the economic factors responsible for the investment slowdown in developing countries (LDC) during the 1980s. A model of debt overhang and LDC investment rates; What the empirical results indicate; Conclusion.

This article examines whether the trade balance of two dynamic export-oriented economies, Korea and Taiwan, exhibits a J-curve effect. The article studies both their bilateral and aggregate trade balance during the flexible exchange-rate era. When the exchange-rate coefficients are unconstrained, we demonstrate that no J-curve effect exists either for bilateral or aggregate trade balances. Several robustness checks confirm the validity of our findings. When a polynomial-distribute lag structure is imposed on exchange-rate coefficients, a J-curve is evident in some cases. The article discusses possible explanations for the general lack of evidence in favor of a J-curve, including the response of a small country's trade balance to exchange-rate changes. [ABSTRACT FROM AUTHOR]

This paper employs the trade-shares methodology to estimate export functions for coffee and cocoa classified according to the market in which they are sold. Because two of the major coffee and cocoa exporting nations belong to the CFA franc zone, we investigate the impact of zone membership on export flows for these two commodities. Our results confirm the theoretical predictions that relative prices and market size are important determinants of exports. Moreover, participation in the zone has, on the whole, been beneficial to the exports of its members. Finally, our study contributes to the literature on the impact of exchange-rate variability on trade flows. It demonstrates that exchange risk depresses the volume of coffee and cocoa exports, displaying a more pronounced impact on zone-member exports. [ABSTRACT FROM AUTHOR]

Examines the factors contributing to the instability of exports in less developing countries. Export receipts and real gross domestic product per capita in U.S. dollars; Movement of commodity prices; Breakdown of the fixed exchange rate system.

Abstract This study aims at making an environmental assessment of the integration of active solar energy systems on building envelopes in southern Europe. More specifically, it focuses on energy production of active solar systems, as well as on the investigation of shading and insolation of indoor spaces in relation to the energy requirements and the visual comfort of inhabitants. For the needs of the present research, five active solar systems and three representative space typologies were selected for in-depth investigation. Autodesk Ecotect Analysis software v.5.2, Desktop Radiance v2.0 Beta and Clean Energy Project Analysis Software Retscreen4 were used for the simulations. The simulation results are presented and discussed comparatively. The findings indicate that the integration of active solar systems contributes to the reduction of the cooling and heating loads. In terms of natural lighting, the integration of active solar systems enables high levels of natural lighting while it minimizes glare issues for the majority of systems. The research highlights the role of building integrated active solar systems, both in the indoor built environment and in energy performance, introducing a comprehensive environmental approach. Moreover, it highlights the importance of an integrated architectural design approach in the built environment. Highlights • Environmental assessment of BIPV and BISTS in horizontal and vertical configuration. • The energy consumption of building typologies under study is positively affected. • Building integrated systems provide adequate shading and insolation conditions. • Results indicate high lighting levels and minimization of glare issues. • BIPV and BISTS form viable solutions for energy retrofitting of existing buildings. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the determinants of research output by European economics departments. We use data from a survey we conducted on the various characteristics of these departments. We pay particular attention to spillovers from North America to Europe and measure these in terms of visiting arrangements between academic institutions across the Atlantic and formal training received by European faculty in North America. We find strong evidence that European economics departments with North-American links have higher research output. [Copyright &y& Elsevier]