XML-Based Hypertext Functionalities for Software Engineering

Hypertext functionalities represent a form of the distilled wisdom of the hypermedia community. Even if they were introduced and advocated already in the pre-Web era, most of these functionalities are absent in current Web browsers. However, such functionalities can be very useful in some specific applicative fields, like for instance browsing complex software engineering documents, using standard WWW components. We propose to exploit the advent of XML as a basic infrastructure for describing software engineering hypertexts. In fact, we describe XMLC, a prototype of an XML browser that, given its modular architecture and general scope, can be seen as the basis for implementing sophisticated hypertext functionalities for software engineering documentation to be maintained and browsed on the Web.     

Heat Transfer Model Performance in Simulation of Process Deviations

Performance of thermal process simulation software was tested for predicting internal product temperature and lethality. Responses were tested for process deviations on canned products with a wide range of heating characteristics for computer-based on-line control of retorts. Static and agitated processes were tested with products exhibiting heating rate factors (fh) ranging from 2 to 70 min. Cans were fitted with thermocouples and subjected to deviations of various types. Center temperature profiles and lethalities predicted by the model in response to dynamic retort temperatures were compared with those measured by thermocouples. Profiles agreed, and process lethalities calculated from predicted and measured profiles agreed ±10% with the model slightly underpredicting measured lethality.     

Performance evaluation of wavelet-based distributed video coding schemes

In this paper we propose and compare different distributed video coding (DVC) schemes based on the use of the wavelet transform, which naturally allows for spatial and other forms of scalability. In particular, we propose a hybrid encoder which utilizes channel codes, and evaluate its performance in the absence of a feedback channel. The proposed scheme uses statistical models for the estimation of the required bitrate at the encoder. We also propose a scheme that is based on a modulo reduction procedure and does not use channel codes at the receiver/transmitter. These schemes are compared with more conventional coders that do not or only partially exploit the distributed coding paradigm. Experimental results show that the considered schemes have good performance when compared with similar asymmetric video compression schemes, and that DVC can be an interesting option in appropriate scenarios.     

Deposition of InGaAsP alloys on GaAs by low pressure metalorganic vapor phase epitaxy: Theory and experiments

A combined thermodynamic-kinetic approach to the epitaxial deposition of InGaAsP alloys on GaAs substrates is presented. Good agreement with experimental group V solid phase incorporation has been found when neglecting the 2V₂ = V₄ (V = As,P) vapor phase reactions, while the group III solid phase composition is well described by simple mass-transport limited processes. InGaAsP materials, lattice matched to GaAs, have been grown in a wide composition range toward the ternary limit [In(0.49)Ga(0.51)P]. Furthermore, high quality InGaAsP/GaAs strained quantum wells with a bandgap below that of GaAs are realized for the first time.     

Algorithmic ADC Offset Compensation by Nonwhite Data Chopping: System Model and Basic Theoretical Results

This paper is devoted to show the impact of nonwhite chopping on the offset compensation in time-interleaved analog-to-digital converters. We develop a theoretical framework allowing the selection of optimal chopping sequences. We show that, on the one hand, the adoption of these (generally nonwhite) sequences allows to achieve faster offset compensation (thus increasing the signal-to-noise ratio) and, on the other hand, a better spectral shaping (thus increasing the spurious-free dynamic range). As a byproduct of our analysis, we prove that the average offset estimation which is used in many ADC implementations is asymptotically the best available linear estimation of offset that, in turn, is the best estimation when the signal to be converted can be assumed to be a Gaussian process.      

Sequence profile of the parallel beta helix in the pectate lyase superfamily

The parallel beta helix structure found in the pectate lyase superfamily has been analyzed in detail. A comparative analysis of known structures has revealed a unique sequence profile, with a strong positional preference for specific amino acids oriented toward the interior of the parallel beta helix. Using the unique sequence profile, search patterns have been constructed and applied to the sequence databases to identify a subset of proteins that are likely to fold into the parallel beta helix. Of the 19 families identified, 39% are known to be carbohydrate-binding proteins, and 50% belong to a broad category of proteins with sequences containing leucine-rich repeats (LRRs). The most striking result is the sequence match between the search pattern and four contiguous segments of internalin A, a surface protein from the bacterial pathogen Listeria monocytogenes. A plausible model of the repetitive LRR sequences of internalin A has been constructed and favorable 3D-1D profile scores have been calculated. Moreover, spectroscopic features characteristic of the parallel beta helix topology in the pectate lyases are present in the circular dichroic spectrum of internalin A. Altogether, the data support the hypothesis that sequence search patterns can be used to identify proteins, including a subset of LRR proteins, that are likely to fold into the parallel beta helix.