Abstract
In this paper we propose a divisive top-down clustering method designed for interval and histogram-valued data. The method provides a hierarchy on a set of objects together with a monothetic characterization of each formed cluster. At each step, a cluster is split so as to minimize intra-cluster dispersion, which is measured using a distance suitable for the considered variable types. The criterion is minimized across the bipartitions induced by a set of binary questions. Since interval-valued variables may be considered a special case of histogram-valued variables, the method applies to data described by either kind of variables, or by variables of both types. An example illustrates the proposed approach.

Abstract
The empirical studies in the area of Open Innovation (OI) reveal that there is a significant bias in favour of countries on the technological frontier. The present study aims to bridge this gap by examining firms in Portugal, a country at an intermediate stage of technological development. Based on 70 innovative firms, we found that whatever perspective of the OI model is considered, firms tend, on average, to share a relatively closed innovation model when compared with firms located in countries where technological development is advanced. About a quarter of the surveyed firms implemented the OI model in their innovation strategy/business, this being much more widely disseminated regarding the absorption of external knowledge/technology, with almost 40% of firms surveyed acknowledging its use in comparison with the perspective of transfer of knowledge/technology to other organisations - less than 10% provide their "surplus technology" to other organisations. This result may indicate a lack of awareness of the economic potential of making internally created technologies available to third parties, albeit this potential might also depend on other circumstances such as technology architecture (the system and interdependence of technologies).

Abstract
Tapering single mode-multimode-single mode structures to enhance sensitivity is proposed and experimentally demonstrated. 50 mm-long coreless MMF sections are spliced between SMFs and tapered. They are characterized in strain and an increase in strain sensitivity is obtained with taper diameter reduction. Sensitivities as high as -23.69 pm/mu epsilon for the 15 mu m taper are attained. A combination of an untapered and tapered SMS is proposed as a sensing system for the simultaneous measurement of strain and temperature.

Abstract
In this work a fiber optic interferometric system for differential refractive index measurement is described. The system is based on a white light Mach-Zehnder configuration, with serrodyne phase modulation, to interrogate two similar non-adiabatic tapered optical fiber sensors in a differential scheme. In this situation it is possible to measure the refractive index independent of temperature. Signal processing with low cost digital instrumentation developed in Labview environment allows a detectable change in refractive index of Delta n approximate to 2x10(-6), which is, from the best of our knowledge the highest resolution achieved using a fiber taper device. The results demonstrate the potential of the proposed scheme to operate as chemical and biological sensing platform.

Abstract
We present a jamming protocol for secrecy-enhanced wireless networks in which otherwise silent devices are selected as jammers to cause interference to potential eavesdroppers. This cooperative protocol includes several jammer selection policies that lead to different levels of secrecy-energy tradeoffs. Our results show that there is some advantage over selecting well-connected jammers and there is a need for a minimum number of jammers for the energy cost of jamming to payoff.

Abstract
PhenoSat is an experimental software tool that extracts phenological information from satellite vegetation index time-series. Temporal satellite NDVI data provided by VEGETATION sensor from three different vegetation types (Vineyard, Closed Deciduous Forest and Deciduous Shrubland with Sparse Trees) and for different geographical locations were used to test the ability of the software in extracting vegetation dynamics information. Six noise reduction filters were tested: piecewise-logistic, Savitzky-Golay, cubic smoothing splines, Gaussian models, Fourier series and polynomial curve fitting. The results showed that PhenoSat is an useful tool to extract phenological NDVI metrics, providing similar results to those obtained from field measurements. The best results presented correlations of 0.89 (n=6; p<0.01) and 0.71 (n=6; p<0.06) for the green-up and maximum stages, respectively. In the fitting process, the polynomial and Gaussian algorithms over smoothed the peak related with a double-growth season, the opposite to the other methods that could detect more accurately this peak.