Relational heuristics for the design of deterministic programs

Summary It has been shown that the design of deterministic programs can be formulated as the resolution of relational equations. Because relational calculi are not sufficiently structured, there are no algorithmic solutions to relational equations. In this paper, we formulate some heuristic solutions to these equations.Part of this work was carried out while the first and second author were at Laval University in Québec. Canada: it was supported by the National Research Council of Canada through a research grant to the first author and a scholarship to the second author. Presently, this research is supported by a grant to the first and third authors from the Tunisian Council on Scientific and Technical Research     

Simple proof of unconditional controllability and observability

A direct proof using a frequency-domain argument is given of Chu's theorem on complete controllability and observability for every nonzero input and output matrix.     

The structure and ultrastructure of the egg capsules of stoneflies of the genus Isoperla (Insecta,Plecoptera, Perlodidae)

The egg capsules of five systellognathan stoneflies species representing the genus Isoperla (Plecoptera, Perlodidae) have been investigated using light and electron microscopes (SEM and TEM). We consider the structural modifications of egg coverings (egg capsules, eggshells) like: a shape of a capsule, presence of structures fixing an egg to the substratum under water, intrachorionic aeropylar system facilitating gas exchange as a factor adapting an egg/embryo to the environment. The structures protecting eggs against desiccation during a female flight before oviposition into water as well as against the dangers of external mechanical injury caused by turbulences in rapid water currents of mountain streams are described and discussed. The ground plan of the egg capsule in arctoperlarian stoneflies is also discussed.     

Synchronization of pneumatic vibroexciters under air cushion operating mode in a self-exciting autovibration regime

A synchronization and phase control method for pneumatic vibroexciters that operate under a self-exciting vibration mode was proposed using a channel with an aerodynamic link. A mathematical model for nonlinear equations that numerically described the dynamics of two vibroexciters was built. Results showed that the qualitative model described the dynamics of a mechanical system. Vibrations of equal phases were obtained in both vibroexciters. A consistent pattern of transformation into a self-exciting vibration regime was determined. The synchronization conditions of the vibroexciters were presented. The effects of the geometric parameters of the synchronization channel on the vibrations of the working body of a vibroexciter were determined. Lastly, the range of the vibration transformation of the vibroexciters toward a synchronous equal frequency was investigated.     

Ontology‐based model‐driven development of a destination management portal: Experience and lessons learned

We present a case study in model‐driven development of an e‐tourism portal that we chose to develop through generation from a domain model encoded as an ontology. We present (1) the requirements of e‐tourism portal, which dictated its high‐level design; (2) the principles behind our implementation strategy, including the use of a domain ontology as a starting model within the context of a model‐driven transformational approach; (3) the ontology development process and the code generation strategy used; and (4) the lessons learned. In particular, we compare our experiences to those reported in the model‐driven engineering (MDE) literature along 3 dimensions, ie, (1) the impact of MDE on the development process, (2) the choice of the modeling approach, and (3) the impact of code generation on design and code quality and testing. Overall, our experiences corroborated some of the theoretical claims and many of the practical experiences with MDE. Key findings include (1) model‐driven development makes maintenance, not development, more efficient; (2) it does require a higher skill level than traditional development; (3) clients and managers need to be educated into what incrementality means in a generative approach; (4) UML is neither necessary nor sufficient to handle the required representational flexibility; (5) it is difficult to build models that are good for both human consumption and code generation; and (6) it is difficult to generate code that is, simultaneously, efficient, pretty, and easy to maintain. We conclude by summarizing the findings of the paper.     

A Concept Formation Based Approach to Object Identification in Procedural Code

Legacy software systems present a high level of entropy combined with imprecise documentation. This makes their maintenance more difficult, more time consuming, and costlier. In order to address these issues, many organizations have been migrating their legacy systems to emerging technologies. In this paper, we describe a computer-supported approach aimed at supporting the migration of procedural software systems to the object-oriented (OO) technology. Our approach is based on the automatic formation of concepts, and uses information extracted directly from code to identify objects. The approach tends, thus, to minimize the need for domain application experts.     

新疆罗布泊盐湖卤水的氚同位素特征及其地质意义

新疆罗布泊罗北凹地盐湖第四系上部盐层中蕴藏丰富的卤水,卤水中富含钾(KCI平均品位1．40％),潜卤层上部的卤水中检测到较高含量的氚。本文研究罗布泊富钾卤水氚的分布特征,由活塞模型和全混模型算得罗北凹地表层卤水的平均年龄为36—80a．卤水中含有大量的核爆氚,表明自1952年以来通过干盐湖发生过大气降水的补给。含氚的现代降水经由溶蚀孔隙十分发育的包气带盐壳渗入地下后,与浅层卤水均匀混合,由于卤水的蒸发作用缓慢,蒸发过程中氚同位素发生分馏,“轻水”蒸发,氚在残余水体(潜卤水)中富集。潜卤水氚含量的平面分布特征主要反映出以蒸发排泄为主的盐湖地下水流网特征。     

Bioactive and Sensory Properties of Herbal Spirit Enriched with Cocoa (Theobroma cacao L.) Polyphenolics

In the Southeast European and Mediterranean regions, consumption of various alcoholic beverages in the form of plain and aromatized spirits and liqueurs is an important part of traditional local gastronomy. Especially herbal spirits and liquors are widely spread and consumed. The objective of this study was to evaluate the potential of using cocoa raw materials (cocoa beans, cocoa nibs or cocoa liquor) in order to enhance the bioactive profile of traditional herbal liqueur, and to produce an appealing cocoa-flavoured alcoholic beverage. Therefore, the polyphenolic profile, antioxidative and sensory properties of herbal liquors containing the macerated cocoa raw materials were monitored during 6 months, in order to evaluate the kinetics of cocoa polyphenols release and optimise the maceration procedure for obtaining the best cocoa-enriched herbal spirit. Compared to plain herbal liquor without the additions, the obtained herbal liqueurs exhibited significantly higher content of polyphenolic antioxidants. Among the used cocoa raw materials for the maceration, cocoa nibs were evaluated as the best source of polyphenolic compounds (herbal liqueur containing cocoa nibs, 3,081.82 mg GAE/L), followed by cocoa liquor (1,897.73 mg GAE/L) and cocoa beans (1,358.64 mg GAE/L). Prolonged maceration time (up to 6 months) resulted with an increase in the content of polyphenolic compounds and the antioxidant capacity of herbal liqueurs. Herbal liqueurs containing the cocoa raw materials of bigger particle size (cocoa beans and cocoa nibs) exhibited better sensory properties (overall acceptability and chocolate-like flavour) than herbal liqueur containing cocoa liquor.