Image Analysis Techniques for Automated Hazelnut Peeling Determination

According to FAO statistics, in 2000, Italy was the second largest hazelnut (Corylus avellana, L. 1753) producer in the world. The price of the stock depends on the nut quality (kernel/nut ratio, nut and seed defect, percentage of peeling, and taste panel scores). The evaluation of peeling efficiency after toasting is generally conducted by trained operators in sight on 100 kernels. This work tests two alternative objective methods of after toasting peeling evaluation based on image analysis. Eleven hazelnut cultivars were analyzed and results were compared with the ones assessed by trained operators. Images were analyzed with two statistical approaches: fixed values of RGB thresholding and trained K Nearest Neighbors (KNN). Root mean squared error (RMSE), estimating the comparison between operators and the two image analysis-based techniques, shows better results for KNN (6.6) with respect to fixed threshold (15.9).     

Electrochemical properties of self-assembled monolayer based on mono-(6-deoxy-6-mercapto)-β-cyclodextrin toward controlled molecular recognition

The present work describes the construction of nanoporous assemblies based on single self-assembled monolayer (SAM) of mono-(6-deoxy-6-mercapto)-β-cyclodextrin (βCDSH) and two-component monolayers of βCDSH and 11-mercaptoundecanoic acid. An investigation of its supramolecular properties toward the tricyclic antidepressants drugs chlorprothixene and imipramine is also presented. The adsorption process was investigated by using surface plasmon resonance and the selectivity of the SAM was verified by using electroactive species permeable and not permeable into the cyclodextrin SAM, such as ferrocenemonocarboxylic acid, hexacyanoferrate, methylene blue and hexamineruthenium (II). The redox probe was chosen based on its capability to permeate the grafted cyclodextrin molecules and its electrochemical characteristics. It was applied to imipramine and chlorprothixene competitive assay by the mono-(6-deoxy-6-mercapto)-β-cyclodextrin self-assembled cavity. Finally, the pK_a of the surface and its effects on thee host-guest interaction properties were also investigated.     

Information-Driven Search Strategies in the Board Game of CLUE $^{circit{R}}$

This paper presents an information-driven sensor management problem, referred to as treasure hunt, which is relevant to mobile-sensor applications such as mine hunting, monitoring, and surveillance. The objective is to infer a hidden variable or treasure by selecting a sequence of measurements associated with multiple fixed targets distributed in the sensor workspace. The workspace is represented by a connectivity graph, where each node represents a possible sensor deployment, and the arcs represent possible sensor movements. An additive conditional entropy reduction function is presented to efficiently compute the expected benefit of a measurement sequence over time. Then, the optimal treasure hunt strategy is determined by a novel label-correcting algorithm operating on the connectivity graph. The methodology is illustrated through the board game of CLUE^reg, which is shown to be a benchmark example of the treasure hunt problem. The game results show that a computer player implementing the strategies developed in this paper outperforms players implementing Bayesian networks, Q-learning, or constraint satisfaction, as well as human players.     

Photovoltaic potential induced by 10 μm laser radiation in Siphotodiodes

Photon drag and photovoltaic response observed in p⁺/n and n⁺/p silicon junctions excited by moderated-power-density 10-μm radiation are discussed. A multistep multiphotonic process through intermediate states located within the energy gap is proposed as the mechanism responsible for the photovoltaic potential     

On trellis-based truncated-memory detection

We propose a general framework for trellis-based detection over channels with infinite memory. A general truncation assumption enables the definition of a trellis diagram, which takes into account a considered portion of the channel memory and possible coding memory at the transmitter side. It is shown that trellis-based maximum a posteriori (MAP) symbol detection algorithms, in the form of forward-backward (FB) algorithms, can be derived on the basis of this memory-truncation assumption. A general approach to the design of truncated-memory (TM) FB algorithms is proposed, and two main classes of algorithms, characterized by coupled and decoupled recursions, respectively, are presented. The complexity of the derived TM-FB algorithms is analyzed in detail. Moreover, it is shown that MAP sequence detection algorithms, based on the Viterbi algorithm, follow easily from one of the proposed classes. Looking backward at this duality between MAP symbol detection algorithms and MAP sequence detection algorithms, it is shown that previous solutions for one case can be systematically extended to the other case. The generality of the proposed framework is shown by considering various examples of stochastic channels. New detection algorithms, as well as generalizations of solutions previously published in the literature, are embedded in the proposed framework. The obtained results do suggest that the performance of the proposed detection algorithms ultimately depends on the truncation depth, almost regardless of the specific detection strategy.     

Room-Temperature Degradation of t-Zr(Pr)O2 in an Aqueous Suspension Revealed by Perturbed Angular Correlations

This paper deals with the phase stability of an aqueous suspension of tetragonal Zr_0.9Pr_0.1O₂ (20 wt%/vol%) at room temperature as a function of the aging time. The suspension is investigated in situ using the highly localized Perturbed Angular Correlations technique. The results indicate that an almost fully reversible degradation process toward monoclinic zirconia takes place through a first-order reaction of rate constant k =0.7 day⁻¹. Two successive diffusion mechanisms are observed that are interpreted as OH⁻ ions' migration in the grain surface and then, as proton defects' diffusion into the bulk.     

A New Instrument for Real-Time Ethernet Performance Measurement

Ethernet is now becoming a popular physical layer for industrial communications due to its reliability, performance, and widespread use. Its actual cutting edge is a minimum cycle time on the order of 100 mus and a jitter of 1 mus. Usually, high-cost laboratory devices are used to log network traffic, but they are still not suitable for an industrial environment. In this paper, a field-programmable-gate-array-based instrument is proposed to log 100-Mb/s Ethernet frames, assigning them a high-resolution time stamp. Full-duplex full-rate network traffic is duplicated and sent through two auxiliary Ethernet ports to a personal-computer-based monitor station for frame analysis. A prototype has been realized to verify feasibility and performance. Results show that the proposed instrument introduces a maximum delay of about 500 ns. The measurement capabilities are comparable with commercial instruments: The time-stamp assignment has a jitter of 150 ns measured on a test frame set.     

Advanced testing procedures for high performance coatings

In the first part of this work, an integrated approach incorporating electrochemical (electrochemical impedance spectroscopy), calorimetric (differential scanning calorimetry), mechanical (dynamic mechanical thermal analysis), and infrared spectroscopy (Fourier transform infrared spectroscopy) techniques was used to characterize some organic coatings from the automotive industry. Comparison of the results obtained with different techniques allows not only a higher precision in the evaluation of natural or artificial degradation, which is very difficult to obtain using traditional techniques, but also better data interpretation and, therefore, the possibility of understanding the different degradation mechanisms. In the second part, some preliminary results concerning the comparison of salt spray exposure and EIS measurements are discussed. The statistical analysis of the results showed that the degradation mechanism in the two cases is completely different and, therefore, the information which is obtained with the two testing approaches is also different. With EIS measurements obtained in immersion, it is possible to monitor, in particular, the barrier properties of the coatings, which are dominated by the presence of defects. In the case of salt spray (without scratch), the main property to be measured is the loss of adhesion which causes blister formation. Presented at the 77th Annual Meeting of the Federation of Societies for Coatings Technology, on October 18–22, 1999, in Dallas, TX. Dept. of Materials Engineering, Via Mesiano 77, Trento, Italy. e-mail: Flavio.Deflorian@ing.unitn.it; Stefano.Rossi@ing.unitn.it; Bonora@ing.unitn.it. Dept. ICMMPM, Via Eudossiana, Rome, Italy. e-mail: Lorenzo.Fedrizzi@ing.unitn.it.     

Guardians for Ambient-Based Monitoring

In the Mobile Ambients of Cardelli and Gordon an ambient is a unit for mobility, which may contain processes (data) and sub-ambients. Since the seminal work of Cardelli and Gordon, several ambient-based calculi have been proposed (Seal, Box-π, Safe Ambients, Secure Safe Ambients, Boxed Ambients), mainly for supporting security. At the operational level these (box- and) ambient-based calculi differ only in the capabilities of processes. We propose a way of extending ambient-based calculi, which embodies two principles: an ambient is a unit for monitoring and coordination, the name of an ambient determines its (monitoring and coordination) policy. More specifically, to each ambient we attach a guardian, which monitors the activity of sub-components (i.e. processes and sub-ambients) and the interaction with the external environment. In our proposal, guardians and processes play a dual role: guardians are centralized entities monitoring and inhibiting actions, while processes are decentralized entities performing actions. We exemplify the use of guardians for enforcing security properties.     

A low-power transmission-gate-based 16-bit multiplier for digital hearing aids

The most widespread 16-bit multiplier architectures are compared in terms of area occupation, dissipated energy, and EDP (Energy-Delay Product) in view of low-power low-voltage signal processing for digital hearing aids and similar applications. Transistor-level simulations including back-annotated wire parasitics confirm that the propagation of glitches along uneven and re-convergent paths results in large unproductive node activity. Because of their shorter full-adder chains, Wallace-tree multipliers indeed dissipate less energy than the carry-save (CSM) and other traditional array multipliers (6.0 µW/MHz versus 10.9 µW/MHz and more for 0.25 µm CMOS technology at 0.75 V). By combining the Wallace-tree architecture with transmission gates (TGs), a new approach is proposed to improve the energy efficiency further (3.1 µW/MHz), beyond recently published low-power architectures. Besides the reduction of the overall capacitance, minimum-sized transmission gate full-adders act as RC-low-pass filters that attenuate undesired switching. Finally, minimum size TGs increase the V _dd to ground resistance, hence decreasing leakage dissipation (0.55 nW versus 0.84 nW in CSM and 0.94 nW in Wallace).