Optimal multisensor data fusion for linear systems with missing measurements

Multisensor data fusion has attracted a lot of research in recent years. It has been widely used in many applications especially military applications for target tracking and identification. In this paper, we will handle the multisensor data fusion problem for systems suffering from the possibility of missing measurements. We present the optimal recursive fusion filter for measurements obtained from two sensors subject to random intermittent measurements. The noise covariance in the observation process is allowed to be singular which requires the use of generalized inverse. Illustration example shows the effectiveness of the proposed filter in the measurements loss case compared to the available optimal linear fusion methods.<br /

Device for tensioning test specimens within an hermetically sealed chamber

The device is characterized by a support column adapted to be received within an insulated, hermetically sealable chamber. A plurality of anchor pins are mounted on the column for releasibly connecting thereto a plurality of test specimens. A plurality of axially displaceable pull rods are received by the column in coaxial alignment with the anchor pins. One end of each pull rod is provided with a coupling for connecting the pull rod to a test specimen. The opposite end of the pull rod is entended through a cover plate and adapted to be connected with a remotely related linear actuator through a connecting link including a load cell for measuring stress as the pull rod is placed in tension by the actuator

Labor Market Transitions in Peru

Traditional labor market analysis based solely on the net unemployment rate fails to explain the apparent paradox between a relatively moderate unemployment rate in Peru (around 10%, with a weak sensibility to wide macroeconomic fluctuations), and the fact that unemployment is one of the major issues in Peru. One possible explanation is that this static indicator of cross section net unemployment balance is compatible with high flows in and out of employment states. To address these issues we needed to conduct a dynamic analysis using panel data. Using the Peruvian national household survey (ENAHO), we constructed a panel of working age individuals at the national level for the period 1997-1999. Like previous work in developing countries, we found that there is an important degree of job mobility in Peru. We also found that most of the transitions occur between employment and inactivity instead of between employment and unemployment. We also showed that the rate of permanent unemployment is very low so that unemployment would be essentially a frictional phenomenon. Further, considering the different transition states, we elaborated an unconditional transition profile, including individual and household characteristics, like gender, age and education levels for example, associated with each transition status. Finally, after examining these labor market transitions and the possible sample selection bias, we estimated a multinomial logit model. This model allowed us to appreciate the (conditional) incidence of individual and household characteristics as well as the effects of different shocks on the labor transition states.

The role of landscape design in improving the microclimate in traditional courtyard buildings in hot arid climates

peer reviewedArab Islamic landscape design forms a unique source of inspiration for landscape architecture in barren open spaces of the Middle East. Arab Islamic gardens adopted a system marked by perfect responsiveness to environment. The design of urban landscape and gardens in Arab Islamic culture was similarly guided by the dictation of aridity. The need to provide shade, to prevent dust and to conserve water meant that urban open spaces and gardens were sheltered and enclosed. Alhambra in Moorish Spain and the Al-Suhaymi House in Islamic Cairo are two useful historical references for vernacular Islamic landscape designs. This paper presents an overview of landscape design considerations for the composition of vegetation and water and initial observations of their influence in controlling and improving the microclimate in courtyards buildings as a way of passive cooling in the Middle East region. This paper is a part of a Master’s thesis in the field of passive landscape strategies at Wageningen University. The objective is to identify the comfort improvements potential of successfully-planned and integrated landscape design in traditional courtyard buildings. The layout and plant material of Alhambra, Generalife courts and Al-Suhaymi court in Islamic Cairo are examined and evaluated. This study demonstrates that in arid environments, the landscape planning, the composition of vegetation and water and choice of planting material all have important consequences in creating thermally-pleasant environments