Le langage de programmation Scheme est reconnu pour son puissant système de macro-transformations. La représentation du code source d'un programme, sous forme de données manipulables par le langage, permet aux programmeurs de modifier directement l'arbre de syntaxe abstraite sous-jacent. Les macro-transformations utilisent une syntaxe similaire aux procédures régulières mais, elles définissent plutôt des procédures à exécuter lors de la phase de compilation. Ces procédures retournent une représentation sous forme d'arbre de syntaxe abstraite qui devra être substitué à l'emplacement de l'appel du transformateur. Les procédures exécutées durant la phase de compilation profitent de la même puissance que celles exécutées durant de la phase d'évaluation. Avec ce genre de système de macro-transformations, un programmeur peut créer des règles de syntaxe spécialisées sans aucun coût additionnel en performance: ces extensions syntactiques permettent l'abstraction de code sans les coûts d'exécution habituels reliés à la création d'une fermeture sur le tas. Cette représentation pour le code source de Scheme provient directement du langage de programmation Lisp. Le code source est représenté sous forme de listes manipulables de symboles, ou bien de listes contenants d'autres listes: une structure appelée S-expression. Cependant, avec cette approche simpliste, des conflits de noms peuvent apparaître. En effet, l'association référée par un certain identifiant est déterminée exclusivement par le contexte lexical de celui-ci. En déplaçant un identifiant dans l'arbre de syntaxe abstraite, il est possible que cet identifiant se retrouve dans un contexte lexical contenant une certaine association pour un identifiant du même nom. Dans de tels cas, l'identifiant déplacé pourrait ne plus référer à l'association attendue, puisque cette seconde association pourrait avoir prévalence sur la première. L'assurance de transparence référentielle est alors perdue. En conséquence, le choix de nom pour les identifiants vient maintenant influencer directement le comportement du programme, générant des erreurs difficiles à comprendre. Les conflits de noms peuvent être corrigés manuellement dans le code en utilisant, par exemple, des noms d'identifiants uniques. La préservation automatique de la transparence référentielle se nomme hygiène, une notion qui a été beaucoup étudiée dans le contexte des langages de la famille Lisp. La dernière version du Scheme revised report, utilisée comme spécification pour le langage, étend ce dernier avec un support pour les macro-transformations hygiéniques. Jusqu'à maintenant, l'implémentation Gambit de Scheme ne fournissait pas de tel système à sa base. Comme contribution, nous avons ré-implémenter le système de macro de Gambit pour supporter les macro-transformations hygiéniques au plus bas niveau de l'implémentation. L'algorithme choisi se base sur l'algorithme set of scopes implémenté dans le langage Racket et créé par Matthew Flatt. Le langage Racket s'est grandement inspiré du langage Scheme mais, diverge sur plusieurs fonctionnalités importantes. L'une de ces différences est le puissant système de macro-transformation sur lequel Racket base la majorité de ses primitives. Dans ce contexte, l'algorithme a donc été testé de façon robuste. Dans cette thèse, nous donnerons un aperçu du langage Scheme et de sa syntaxe. Nous énoncerons le problème d'hygiène et décrirons différentes stratégies utilisées pour le résoudre. Nous justifierons par la suite notre choix d'algorithme et fourniront une définition formelle. Finalement, nous présenterons une analyse de la validité et de la performance du compilateur en comparant la version originale de Gambit avec notre version supportant l'hygiène. / The Scheme programming language is known for its powerful macro system. With Scheme source code represented as actual Scheme data, macro transformations allow the programmer, using that data, to act directly on the underlying abstract syntax tree. Macro transformations use a similar syntax to regular procedures but, they define procedures meant to be executed at compile time. Those procedures return an abstract syntax tree representation to be substituted at the transformer's call location. Procedures executed at compile-time use the same language power as run-time procedures. With the macro system, the programmer can create specialized syntax rules without additional performance costs. This also allows for code abstractions without the expected run-time cost of closure creations. Scheme's representation of source code using values inherits that virtue from the Lisp programming language. Source code is represented as a list of symbols, or lists of other lists: a structure coined S-expressions. However, with this simplistic approach, accidental name clashes can occur. The binding to which an identifier refers to is determined by the lexical context of that identifier. By moving an identifier around in the abstract syntax tree, it can be caught within the lexical context of another binding definition with the same name. This can cause unexpected behavior for programmers as the choice of names can create substantial changes in the program. Accidental name clashes can be manually fixed in the code, using name obfuscation, for instance. However, the programmer becomes responsible for the program's safety. The automatic preservation of referential transparency is called hygiene and was thoroughly studied in the context of lambda calculus and Lisp-like languages. The latest Scheme revised report, used as a specification for the language, extend the language with hygienic macro transformations. Up to this point, the Gambit Scheme implementation wasn't providing a built-in hygienic macro system. As a contribution, we re-implemented Gambit's macro system to support hygienic transformations at its core. The algorithm we chose is based on the set of scopes algorithm, implemented in the Racket language by Matthew Flatt. The Racket language is heavily based on Scheme but, diverges on some core features. One key aspect of the Racket language is its extensive hygienic syntactic macro system, on which most core features are built on: the algorithm was robustly tested in that context. In this thesis, we will give an overview of the Scheme language and its syntax. We will state the hygiene problem and describe different strategies used to enforce hygiene automatically. Our algorithmic choice is then justified and formalized. Finally, we present the original Gambit macro system and explain the changes required. We also provide a validity and performance analysis, comparing the original Gambit implementation to our new system.

The commercial use of hemp fiber in the construction industry within the United States is non-existent. This lack of use is because of State and Federal laws forbidding the growth of hemp in the United States, which has led to a lack of research. Not having an established supply chain for hemp and coupled with limited research has put the United States behind other countries in finding viable options for these renewable resources. This is a study of the performance of raw hemp fibers and processed hemp twine in a cement past mixture subjected to tensile loading. Three water/cement ratios (0.66, 0.49, 0.42) were considered. Replacement of cement with fly ash is also part of the program to see if it affects the performance of the system. A detailed description of the method of applying the tensile load to the micro/macro fibers along with the fixture setup is part of this article. The results of this investigation show the hemp twine and fibers will bond to the cement matrix and they can carry higher tensile loads at higher w/c ratios. This study shows that 30 mm embedment length is best for hemp macro fibers and 20 mm embedment for hemp micro fibers. This study also includes a comparative investigation of the performance of hemp fibers to synthetic and steel fibers added to a concrete mix. This investigation examined the compressive strength of the fiber-reinforced concrete mixes, flexural capacity, ductility, flexural toughness and the effects the fibers have on Young’s modulus of elasticity. All fibers were introduced to the same mix design (w/c = 0.49) with replacement of 25% of cement with fly ash. Hemp micro fibers at the same dosing rate a synthetic micro fibers has a slightly higher toughness and equivalent flexural strength. Hemp macro fibers at a higher dosing rate as compared to synthetic fibers will have similar toughness and equivalent flexural strength. Steel fibers performed better than the synthetic and natural fibers at 28-day compressive strength.

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The aim of this paper is to reveal how the European – Russian political cooperation in the common Baltic Sea Region developed over the last twenty years, ending up at the recently adopted European Union Strategy for the Baltic Sea Region, which excludes Russian participation. This single case study is divided into two well-defined historical periods: starting from the fall of the Berlin Wall until the Eastern Bloc European enlargement and from 2004 to the adoption of the European Union Strategy for the Baltic Sea region in 2009; where comparison and process-tracing methods are applied to connect different variables that matter for clarifying the current state of relations. Furthermore, the analysis is conducted with the help of Constructivist and Neo-Realist theories for two purposes – to achieve stronger scientific explanation and to avoid too loose interpretation of the events. The results show that the Strategy for the Baltic Sea Region is often seen and understood differently by the various political actors, but consequently this leads to a situation in which the role of Russia in the common region remains unclear. When it comes to defining the Russian position today, the Baltic Sea Region provides a good climate for collaboration but so far, the European Union has failed to recognize that the Russian Federation although with a limited access to the sea, remains an actor that should not be ignored. Russia, as well appears confused about its overall foreign policy towards the European Union. Nevertheless, another significant outcome reveals that the levels of regional cooperation have been continuously increasing over the last twenty years, which is an indicator that the Russian presence did not diminish. Finally, the study suggests the European Union Strategy for the Baltic Sea Region is perhaps the beginning of a new tendency towards macro-regional policy development, which will play a future important role in the international relations.

With a strong demand for aquatic products, seaweed is a promising application in a wide range of areas, such as food, medicine and energy. Kenya is seen as a country with great potential of expanding its seaweed industry, and by inspiration from the widespread production of algaes at Zanzibar, improvements and adaptations can be made to fit Kenya. One of the places with proper environmental conditions is Shimoni, situated in the south coast of Kenya, and the purpose of this report is to assist on the expansion of seaweed farming in Shimoni, by assessing the possibilities of deep-water cultivations at site, and mediate strengths, weaknesses, opportunities and threats with the technique. In addition, another purpose is also to map out important stakeholders for starting up and expanding the system. The methods SWOT-analysis and stakeholder mapping have been carried out by literature studies and interviews with local scientists. Results have shown that deep-water techniques are less demanding on the environment than cultivations in the intertidal area and may support the local environment if proper conditions are provided for. Seaweed cultivations have large potential as an additional livelihood opportunity in coastal communities, given that adjustments to changes in market prices and environmental conditions can be met. However, deep water methods require larger initial costs than the ones carried out in the intertidal, hence political and technical support may be crucial for launching the system. These processes may be implemented iteratively as business opportunities arise. In conclusion, field research covering non-expected local aspects is further recommended. / Den globala efterfrågan av havsbaserade produkter ökar, och tycks inte mattas av. Algindustrin ses som ett lovande område att kunna bemöta detta behov på grund av sitt breda användningsområde. Mat, medicin och energi är bara några exempel på vad råvaran kan användas till. Kenya ses som ett land med stor potential att expandera sin nuvarande algindustri. Med inspiration av den närliggande storproducenten Zanzibar kan förbättringar och anpassningar göras för att passa in i Kenya. Ett område med bra miljöförutsättningar är Shimoni, beläget i södra Kenya, vilket är området denna rapport fokuserar på. Syftet med rapporten är att utvärdera möjligheterna för att utvidga algodlingar i området genom att studera potentialen hos djupvattenodling. Detta genom att analysera styrkor, svagheter, möjligheter och hot med den specifika tekniken. Syftet är vidare att kartlägga viktiga aktörer som kan ha betydelse vid en uppstart och expandering av odlingarna. Metoderna SWOT-analys och aktörskartläggning har gjorts med litteraturstudier och intervjuer med lokala forskare, som grund. Resultat har visat att djupvattentekniker är mindre påfrestande på miljön än odlingar belägna närmare strandkanten, och kan vara uppbyggande för den lokala miljön om rätt tekniker används. Algodling har en stor potential som en kompletterande sysselsättning i kustområden, om marknadspriset på råvaran höjs och att en viss miljöstandard upprätthålls. Dock så kräver djupvattenodlingar större initiala kostnader än tekniker som placeras vid lägre vattenstånd, vilket gör att politiskt och tekniskt stöd är avgörande för en möjlig uppbyggnad. Detta kan ske stegvis i takt med att nya affärsmöjligheter uppdagas. Slutligen rekommenderas fältstudier för att studera lokala aspekter som kan förekomma, vilka skiljer sig från litteraturen.

The purpose of this study is to explore the influence on urban employment patterns of changes in demand for commodities by foreign and domestic consumers. Foreign induced changes in commodity demand are reflected in this study by assumed changes in exports of selected comma-· dity groupss ranging from relatively unprocessed groups such as grain, to sophisticated groups such as electrical products and chemicals. The domestic sources of commodity demand change considered in this study are various components of current expenditure by the federal government on health, education and defense programs, as well as on total government expenditure. The influence of these sources of final demand change is traced to the employed populations of Montreal and Toronto metropolitan areas, and the component districts of these urban areas. An important concern is with whether or not some shocks tend to alleviate or accentuate existing unemployment rate disparities between the central city and fringe of Montreal and Toronto. A national input-output system, together with an appended employment allocation matrix is utilized to estimate the urban employment impacts. The area impacts differ because, on the one hand, employment in some industries is affected more than in others, depending on the particular source of final demand change assumed, and on the other hand the proportion of an area's employed population affiliated with a given industry tends to differ from that of other areas. Before implementing the model the latter proposition~ concerning inter-area differences in industrial affiliation pattern of the employed) is supported by theoretical reasoning and empirical analysis. Theoretically different industries have different locational preferences in an urban area, as a result of factors related to technology, cost of production, and market access. Combined with the theoretical assumption concerning minimization of cost and/or distance of travel to work, area differences in the proportion of workers affiliated with a given industry is implied. This hypothesis is not rejected by analysis of variance experiments based on the pattern of male and female employed populations residing in districts of Montreal and Toronto. Adjusted census statistics on the employed population are used in these experiments the adjustment being required in order to make the urban portion of the model consistent with the 1961 input-output system. Implementation of the model reveals that the metropolitan areas of Montreal and Toronto are influenced to similar degrees by the assumed changes in various components of final demand, but that certain sub-metro areas were affected more than others. There is a tendency for suburban and wealthier areas to be affected more than central and less affluent districts though there are important exceptions. Some components of final demand change tend to accentuate existing intra-urban unemployment disparities. It is finally shown how the area impact disaggregated by subpopulation can be used to identify structural factors responsible for inter-area differences in the total impact. The disaggregated impacts also reveal qualitative, or distributional aspects of the aggregate impacts and thus may be of interest to urban planners. It is possibles for example, to check if female or male employees, affiliated with a lower paying industry group, and resident in a relatively poor district of the city, is influenced more than average by a particular type of final demand change. The limitations and possible extensions are finally reviewed. One limitation involves the assumption that given the industry, subpopulations of the employed are discharged at similar rates when there is a fall in product demand. The theory treating labour as a quasifixed factor implies that the lower grades of labour would be discharged at higher rates than the higher grades. Any bias due to the omission of this effect would reinforce the results related to intra-urban unemployment rate disparities, however. Future research suggested by this study include incorporation of the discriminatory discharge effect into the model and further disaggregation of the work force of industries according to occupation or income group. / Doctor of Philosophy (PhD)

Macro Planning of construction projects is among the most challenging tasks faced by the project team. Decisions made during this process have a tremendous impact on the successful execution of the project from its early conceptual phases, through the project construction and completion. For a large majority of construction projects, the current planning practices remain manually based. General and project specific data are communicated among project participants through design drawings in a 2D paper-based format. Due to the interdependence between the different elements and the large amount of information that needs to be manually processed, the current manual implementation approach is very difficult to undertake, and imposes a heavy burden on the project team to carry out the planning process. Various research efforts have been undertaken in an attempt to capture current planning techniques and allow for the development of new innovative and automated ways in planning. The developed planning systems are characterized as responsive decision systems, relying mainly on programmed knowledge and heuristics for decision making, hence reducing or eliminating the role of the human planner. This research presents the framework for a new interactive planning environment called the Virtual Construction Environment (VCE) that supports the thinking process of the project team during the macro planning phase of design-build projects. Unlike previous responsive-type systems developed, the approach utilized in the VCE is supportive to the project team enabling them to be an active participant in the decision making process. The main purpose of the VCE is to assist the project team during decision making, by providing pertinent information necessary for making appropriate decisions in a structured format. This information may be organized, stored, and retrieved by the project team whenever needed during the virtual sessions. The VCE also provides the project team with appropriate tools to test different work execution and site layout planning scenarios early during project development. During the virtual sessions, the project team reconstructs the facility by bringing graphical elements together. The project team's movements and interactions are recorded to capture their thinking process on how to construct the facility (i.e. sequence of major assemblies). Other project participants can retrieve recorded decisions for further review or modification. The project team is also able to specify construction methods, and allocate resources required for the implementation of major assemblies. The VCE guides the project team to perform these interdependent planning functions interactively and concurrently. Using system graphical libraries, major equipment and temporary facilities can be superimposed and displayed as graphical objects for site layout planning. This enables the project team to visually check for space and accessibility conflicts during different virtual construction time intervals. In order to define required information in the VCE, the author has developed a MAcro Planning Information Classification (MAPIC) model under which information required for macro planning decision making could be classified and organized in a structured standardized format. The project team may then retrieve and utilize this information whenever needed during the virtual sessions. A prototype computer tool is developed to illustrate the framework of the VCE. The computer prototype is implemented using available commercial software tools. / Ph. D.