Byggbranschen är idag en av de ledande faktorerna till både avfall och koldioxidutsläpp i Sverige. Detta beror till stor del på råvaruutvinning och användning av jungfruliga material. En stor del av både utsläpp och avfallsmängder skulle kunna minskas genom att nyttja mer återbruk. Ett material som lämpar sig för återbruk är tegel. Syftet med arbetet är att öka återbruk av tegel i Sverige för att minska utsläppen från byggsektorn. Målet med studien är att redogöra återbruksprocessen för tegel och att jämföra skillnader mellan nyproducerat tegel och återbrukat tegel. Metoderna för att ta reda på återbruksprocessen samt skillnader mellan nyproducerat och återbrukat tegel är genom en litteraturstudie och via praktiska tester. Litteraturstudien genomfördes för att skapa större förståelse kring tegel och dess egenskaper samt hur det kan återbrukas. För att jämföra nyproducerat och återbrukat tegel har fyra SIS-tester utförts på massivt nyproducerat, hålat nyproducerat, massivt återbrukat och hålat återbrukat tegel. Återbruksprocessen för tegel är en process som idag används av ett företag som heter Brukspecialisten. Återbruksprocessen har fyra steg som består av en inventering av byggnaden innan rivning, tegelpant på allt tegel som går att återbruka, transport av tegel och tegelhanteringsprocess. Processen bidrar till hållbara, miljösparande och ekonomiska byggnadsmaterial som återanvänds i stället för att slängas på deponi. Återbrukat tegel säljs med tillhörande produktinformation som beskriver tryckhållfasthet, färg, åtgång per m2och rekommenderad typ av murbruk. Dessa steg skapar en återbruksmarknad för tegel som är konkurrenskraftig mot nyproducerat tegel. Resultatet från studien visar att tegel från både 1900- och 1960-talet är återbrukbart och går att använda. Tegel som återbrukas testas och klassas om med hänsyn till tekniska egenskaper från testerna. Teglets nya klassning innebär att teglet kan återanvändas i nya projekt med nya förutsättningar. / The construction industry is currently one of the leading contributors to both waste and carbon dioxide emissions in Sweden. This is largely due to the extraction of raw materials and the use of virgin materials. A significant portion of both emissions and waste could be reduced by utilizing more reuse. One material that is suitable for reuse is bricks. The purpose of this work is to increase the reuse of bricks in Sweden in order to reduce emissions from the construction sector. The goal of the study is to outline the process of reusing bricks and to compare the differences between newly produced bricks and reused bricks. The methods used to understand the process of reusing bricks and the differences between newly produced and reused bricks are through a literature study and practical tests. The literature study was conducted to gain a better understanding of bricks and theirs properties, as well as how they can be reused. To compare newly produced and reused bricks, four SIS tests were conducted for solid newly produced, perforated newly produced, solid reused, and perforated reused bricks. The process of reusing brick is currently performed by a company called Brukspecialisten. The reusing process consists of four steps, which involve conducting a survey of the building before demolition, implementing a brick deposit system for all reusable bricks, transportation of the bricks, and brick handling processes. This process contributes to sustainable, environmentally friendly, and cost-effective building materials that are reused instead of being discarded in landfills. Reused bricks are sold with accompanying product information that describes compressive strength, color, consumption per square meter, and recommended type of mortar. These steps create a competitive market for reused bricks as an alternative to newly produced bricks. The results of the study indicate that bricks from both the 1900s and the 1960s are reusable and can be used. Reused bricks undergoe testing and are reclassified based on theirs technical properties from the tests. The bricks new classification means that they can be reused in new projects with new requirements.

No description available.

Water reuse has become a promising alternative to alleviate stress on conventional freshwater resources in the face of population growth, sea level rise, source water depletion, eutrophication of water bodies, and climate change. Potable water reuse intentionally looks to purify wastewater effluent to drinking water quality or better through the development and implementation of advanced treatment trains. While membrane-based treatment has become a widely-adopted treatment step to meet this purpose, there is growing interest in implementing treatment trains that harness microorganisms as a more sustainable and less energy-intensive means of removing contaminants of emerging concern (CECs), through biological degradation or transformation. In this dissertation, various aspects of the operation of a microbially-active carbon-based advanced treatment train producing water intended for potable reuse are examined, including fate of dissolved organic carbon, underlying microbial populations, and functional genes are explored. Further, dynamics associated with antibiotic resistance genes (ARGs), identified as a microbially-relevant CECs, are also assessed. Overall, this dissertation advances understanding associated with the interplay between and within treatment processes as they relate to removal of various organic carbon fractions, microbially community dynamics, functional genes, and ARGs. Further, when relevant, these insights are contextualized to operational conditions, process upsets, water quality parameters, and other intended water uses within the water industry with the goal of broadening the application of advanced molecular tools beyond the scope of academic research. Specifically, this dissertation illuminates relationships among organic carbon fractions and molecular markers within an advanced treatment train employing flocculation, coagulation, and sedimentation (FlocSed), ozonation, biologically active carbon (BAC) filtration, granular active carbon (GAC) contacting, and UV disinfection. Biodegradable dissolved organic carbon (BDOC) analysis was adapted specifically as an assay relevant to assessing dissolved organic carbon biodegradability by BAC/GAC-biofilms and applied to profile biodegradable/non-biodegradable organic carbon as wastewater effluent passed through each of these treatment stages. Of particular interest was the role of ozonation in producing bioavailable organic carbon that can be effectively removed by BAC filtration. In addition to understanding the removal of fractionalized organic carbon, next generation DNA sequencing technologies (NGS) were utilized to better understand the microbial dynamics characteristic of complex microbial communities during disinfection and biological treatment. Specifically, this analysis was focused on succession and colonization of taxa, genes related to a wide range of functional interests (e.g. metabolic processes, horizontal gene transfer, DNA repair, and nitrogen cycling), and microbial CECs. Finally, NGS technologies were employed to assess the differences between a wide range of water use categories, including conventional drinking water, potable reuse, and non-potable reuse effluent's microbiomes to identify core and discriminatory taxa associated with intended water usage. The outcomes of this dissertation provide valuable information for optimizing carbon-based treatment trains as an alternative to membrane-based treatment for sustainable water reuse and also advance the application of NGS as a diagnostic tool for assessing the efficacy of various water treatment technologies for achieving treatment goals. / Doctor of Philosophy / Several factors have led to increased stress on conventional drinking water sources and widespread global water scarcity. Projections indicate that continued population growth, increased water demand, and degradation of current freshwater resources will negatively contribute to water needs and underscore the need to secure new potable (i.e. fit for human consumption) sources. Water reuse is a promising alternative to offset the growing demands on traditional potable sources and ameliorate negative consequences associated with water scarcity. Discharge of treated wastewater to marine environments is especially a lost opportunity, as the water will no longer be of value to freshwater habitats or as a drinking water source. Water reuse challenges the conventional wastewater treatment paradigm by providing advanced treatment of wastewater effluent to produce a valuable resource that can be safely used directly for either non-potable (e.g., irrigation, firefighting) or potable (i.e., drinking water) applications. The means of achieving advanced treatment of wastewater effluents can take many forms, commonly relying on the utilization of membrane filtration. However, membrane filtration is an intensive process and suffers from high initial costs, high operational costs, membrane fouling with time, and the production of a salty and difficult to dispose of waste stream. These drawbacks have motivated the water reuse industry to explore more sustainable approaches to achieving high quality effluents. One such alternative relies on the utilization of microorganisms to provide biological degradation and transformation of contaminants through a process known as biologically active filtration (BAF). Comparatively to membrane systems, BAF is more cost effective and produces significantly fewer byproducts while still producing high quality treated water for reuse. However, the range in quality of the resulting treated water has not yet been fully established, in part due to the lack of understanding of the complex microbial communities responsible for biological treatment. As water and wastewater treatment technologies have evolved over the past century, many biological treatments have remained largely 'black box' due to the lack of effective tools to identify the tens of thousands of species of microbes that inhabit a typical system and to track their dynamics with time. Instead, analysis has largely focused on basic water quality indicators. This dissertation takes important steps in advancing the implementation of the study of DNA and biodegradable organic carbon (BDOC) analysis to improve understanding of the mechanisms that drive different water reuse treatment technologies and to identify potential vulnerabilities. Insights gained through application of these tools are contextualized to observed operational conditions, process upsets, and water quality measurements. This helped to advance the use of DNA-based tools to better inform water treatment engineering practice. Specifically, this dissertation dives into the relationships between organic carbon and DNA-based markers within an advanced treatment train employing flocculation, coagulation, and sedimentation (FlocSed), ozonation, biologically active carbon (BAC) filtration, granular active carbon (GAC) contacting, and UV disinfection. Development and application of the BDOC test revealed that the bulk of organic carbon entering the treatment train is dissolved. Further, BDOC analysis served to characterize the impact of specific treatment processes and changes in operational conditions on both biodegradable and non-biodegradable organic carbon fractions. Such information can help to inform continued process optimization. Utilization of DNA-based technologies shed light on the functional capacity of microbial communities present within each stage of treatment and the fate of antibiotic resistance genes (ARGs). ARGs are of concern because, when present in human pathogens, they can result in the failure of antibiotics to cure deadly infections. Other functional genes of interest were also examined using the DNA-based analysis, including genes driving metabolic processes and nitrogen cycling that are critical to water purification during BAF treatment. Also, the DNA-based analyses made it possible to better understand the effects of disinfectants on microbes. Interestingly, some ARG types increased in relative abundance (a measure analogous to percent composition) response to treatments, such as disinfection, and others decreased. Characterization of the microbial communities and their dynamic response to changing operation conditions were also observed. For example, it was possible to characterize how the profiles of microbes changed with time, an ecological process called succession, during BAC filtration and GAC contacting. Generally, this analysis, coupled with the functional analysis, shed light on the important, divergent roles of bacterial communities on organic degradation during both BAC and GAC treatment. Finally, a study was conducted that compared the microbiome (i.e. entire microbial community) between a wide range of conventional drinking water, potable reuse water, and non-potable reuse waters. Here it was found that significant differences existed between the microbial communities of water intended for potable or non-potable usage. This work also looked to expand the application of NGS technologies beyond strictly academic research by developing the application of more advanced DNA-based tools for treatment train assessment and monitoring.

Today, functional buildings are being demolished, generating amounts of waste that contribute to the significant climate impact of the construction industry. To counteract this, the Swedish government has established climate goals as incentives for the construction industry to reduce its climate impact. Furthermore, the government has created policies for organisations to transition to a circular economy, where one strategy for the construction industry is to switch to circular construction through the adaptive reuse of buildings and the reuse of building products. Previous studies have focused on identifying opportunities and barriers for actors in the construction industry to implement circular projects. However, there are few studies on how varying incentives affect architects and clients in developing and demanding circular services. The lack of research on the importance of incentives has led this study to investigate and contribute to a deeper understanding of the significance of incentives. Additionally, the possible implications of client incentives on architects' approaches to developing circular services are studied. The study is based on a qualitative approach through literature and interview studies along with a workshop. The literature study was conducted to gain an understanding of the field and contributed to the category model of incentives that was used during the analysis of material from interviews and the workshop. The interview study comprises two stakeholder perspectives, with 4 people representing the architect's perspective and 4 people representing the client's perspective. The results of the interview study were validated and discussed through a workshop conducted with 6people from an architectural firm in Gothenburg. The workshop also aimed to discuss the possible implications of client incentives on architects' approaches to strengthen the study's qualitative approach. Using the category model, material from the literature was coded and categorized, with terms such as drivers being sorted as positive incentives, and terms such as barriers being sorted as negative incentives. Further analysis involved quotes from the empirical data regarding what, according to the stakeholder perspectives, are positive or negative incentives to develop and demand circular services, which were compared with incentives identified through the literature. The categorise empirical data was used to analyse similarities and differences in the incentives, and how client incentives affect architects' approaches. The study's contribution is that different incentives lead to incentive impacts, which significantly influence architects in developing services and competencies and clients in demanding services. The study shows that incentives related to the transition to circular construction and contributing to climate benefits are of great importance. Architects also see business value as a strong incentive to develop circular services. Furthermore, the implications of client incentives do not result in incentives to develop a specific service but rather to develop internal processes to effectively meet varying demands. The study shows that clients' incentives to demand services are driven by strategies, where those who value incentives such as climate benefits as highly as economic ones demand practical services to a greater extent, while others demand services to realize circular strategies. The study shows that the incentives of architects and clients do not differ, but a match between these incentives is crucial for implementing circular services within projects. To enable architects and clients to contribute to the emergence of transformation and reuse requires incentives for organisational development of internal routines, which the study shows can facilitate the development of circular construction. / Idag rivs fullt fungerande byggnader vilket genererar enorma mängder avfall som bidrar till byggbranschens betydande klimatpåverkan. För att motverka detta har svenska regeringen antagit klimatmål som incitament för att byggbranschen ska reducera sin klimatpåverkan. Vidare har regeringen skapat styrmedel för organisationer att ställa om till cirkulär ekonomi, där en strategi för att byggbranschen ska uppnå klimatmålen är att ställa om till cirkulärt byggande genom transformation av byggnader och återbruk av byggprodukter. Tidigare studier har fokuserat på att identifiera möjligheter och hinder för byggbranschens aktörer att genomföra cirkulära projekt. Däremot finns det få studier om hur incitament påverkar arkitekter och beställare att utveckla och efterfråga cirkulära tjänster. Brist på forskning kring incitamentens betydelse gör att denna studie har undersökt och bidragit till ökad förståelse för incitamentens betydelse. Dessutom studeras möjliga implikationer beställares incitament har på arkitekters förhållningssätt att utveckla cirkulära tjänster. Studien baseras på en kvalitativ ansats genom litteratur- och intervjustudier samt en workshop. Litteraturstudien genomfördes för att få förståelse för området och bidrog till den kategorimodell av incitament som nyttjades under analyser av material från intervjuer och workshop. Intervjustudien omfattar två aktörsperspektiv varav 4 personer representerar arkitektperspektivet och 4 personer representerar beställarperspektivet. Intervjustudiens resultat validerades och diskuterades via en workshop som genomfördes med 6 personer från ett arkitektkontor i Göteborg. Workshopen syftade även att diskutera möjliga implikationer av beställarincitament för arkitekters förhållningssätt för att stärka studiens kvalitativa ansats. Med hjälp av kategorimodellen kodades och kategoriserades stoff från litteraturen, där termer likt drivkrafter, sorterats vara positiva incitament, och termer likt hinder, sorterats vara negativa incitament. Det som vidare analyserades var citat från empirin om av vad som enligt aktörsperspektiven är positiva eller negativa incitament att utveckla och efterfråga cirkulära tjänster, vilket ställdes mot incitament som identifierats via litteraturen. Den kategoriserade empirin användes för att analysera likheter och skillnader i incitamenten, och hur beställares incitament påverkar arkitekters förhållningsätt. Studiens bidrag till litteraturen inom cirkulärt byggande är att olika incitament leder till en incitamentspåverkan, vilket har betydande inverkan på arkitekter att utveckla tjänster och kompetenser och beställare att efterfråga tjänster. Incitament kring omställningen till cirkulärt byggande och att bidra till klimatnyttan visar studien är av stor betydelse. Arkitekter ser även affärsvärdet som ett starkt incitament att utveckla cirkulära tjänster. Vidare visar studien att implikationer av beställarincitament inte resulterar i incitament för arkitekter att utveckla en specifik tjänst, utan att utveckla interna rutiner för att effektivt kunna möta varierande efterfrågan. Studien visar också att beställares incitament att efterfråga tjänster styrs av interna strategier, där de som värdesätter incitament som klimatnytta lika högt som ekonomiska efterfrågar praktiska tjänster i större utsträckning, medan andra efterfrågar tjänster för att realisera cirkulära strategier. Slutligen visar studien att arkitekters och beställares incitament inte skiljer sig åt, men att en match incitamenten emellan är avgörande för att implementera cirkulära tjänster inom projekt. För att arkitekter och beställare ska kunna bidra till framväxten av transformation och återbruk förutsätter det incitament för organisatorisk utveckling av interna rutiner, vilket studien visar kan möjliggöra för utveckling av cirkulärt byggande.

Many countries, including South Africa, are facing the reality of insufficient water supplies to meet their present and future water demands due to decreasing freshwater availability and increasing demand. Increased populations and climate changes further exacerbate the problem. South Africa is considered the thirtieth driest country in the world with limited supplies of water which are unevenly distributed. Thus there is a need for alternative water sources to augment the freshwater supply. Wastewater reuse has been identified worldwide as a viable option to augment water supplies. While technologies are available to ensure proper treatment of wastewater to even potable standards, many countries have experienced public resistance to wastewater reuse due to negative perceptions of consumers. For wastewater reuse initiatives to be successful public acceptance is imperative. The aim of this study was to assess perceptions of consumers in the Vaal Triangle on wastewater reuse. This is the first study conducted in the Vaal Triangle on wastewater reuse hence this information can be valuable in future when wastewater reuse projects are implemented A questionnaire to measure perceptions of consumers on wastewater reuse was developed based on previous studies and distributed to people residing in the Vaal Triangle area. A response rate of 74% (515 completed questionnaires) was obtained from 700 distributed questionnaires. The results showed that socio-demographic factors such as age, race, qualification and level of employment affect the perceptions of consumers on wastewater reuse. Additionally, knowledge of wastewater reuse and water scarcity had a positive effect on consumer‟s perceptions. Some of the major reasons why consumers are not receptive to wastewater reuse are health concerns, lack of trust in the implementing agencies, poor management of the plants and safety of chemicals used to treat the water. Lack of knowledge on wastewater reuse was raised as a major concern in the study. All these concerns need to be addressed to ensure success of wastewater reuse projects within the area. Limitations within the study were identified and recommendations for future research were made. / MBA, North-West University, Potchefstroom Campus, 2015

Many countries, including South Africa, are facing the reality of insufficient water supplies to meet their present and future water demands due to decreasing freshwater availability and increasing demand. Increased populations and climate changes further exacerbate the problem. South Africa is considered the thirtieth driest country in the world with limited supplies of water which are unevenly distributed. Thus there is a need for alternative water sources to augment the freshwater supply. Wastewater reuse has been identified worldwide as a viable option to augment water supplies. While technologies are available to ensure proper treatment of wastewater to even potable standards, many countries have experienced public resistance to wastewater reuse due to negative perceptions of consumers. For wastewater reuse initiatives to be successful public acceptance is imperative. The aim of this study was to assess perceptions of consumers in the Vaal Triangle on wastewater reuse. This is the first study conducted in the Vaal Triangle on wastewater reuse hence this information can be valuable in future when wastewater reuse projects are implemented A questionnaire to measure perceptions of consumers on wastewater reuse was developed based on previous studies and distributed to people residing in the Vaal Triangle area. A response rate of 74% (515 completed questionnaires) was obtained from 700 distributed questionnaires. The results showed that socio-demographic factors such as age, race, qualification and level of employment affect the perceptions of consumers on wastewater reuse. Additionally, knowledge of wastewater reuse and water scarcity had a positive effect on consumer‟s perceptions. Some of the major reasons why consumers are not receptive to wastewater reuse are health concerns, lack of trust in the implementing agencies, poor management of the plants and safety of chemicals used to treat the water. Lack of knowledge on wastewater reuse was raised as a major concern in the study. All these concerns need to be addressed to ensure success of wastewater reuse projects within the area. Limitations within the study were identified and recommendations for future research were made. / MBA, North-West University, Potchefstroom Campus, 2015

Submitted in fulfillment of the academic requirements for the degree of Master of Technology in Engineering: Chemical Engineering, Durban University of Technology. Durban. South Africa, 2015. / The textile industry consumes large volumes of water and in turn produces substantial quantities of polluted effluents. Approximately 30% of reactive dyes used during the textile processing remain unfixed on fibres and are responsible for the colouration in effluents. Various conventional methods are being used to treat textile effluent. However, the disadvantage of these methods is that total colour removal is not achieved and chemical by-products are introduced from the use of chemicals. The water quality produced therefore does not meet the requirement for textile reuse. Membrane based processes provide interesting possibilities of separating hydrolysed dye stuff and dyeing auxiliaries, thereby reducing colouration and COD content. They can be employed to treat reactive dye bath effluent to recover the salts and water for the purpose of reuse. This study aimed at integrating membrane processes into the reactive dye bath of a textile industry. The objectives were to determine the quality of permeate produced in terms of removal of organics, ascertain its reusability for dyeing, investigate the production rate in terms of permeate fluxes and finally to investigate the cleanability and flux recovery of the membranes. Three effluent samples were chosen for this study based on the dyeing recipe; Light shade, Medium shade and Dark shade. Ultrafiltration (UF) and Nanofiltration (NF) membrane processes were employed to treat the reactive dye bath effluents to recover the salts and water. Investigations were conducted firstly with UF as a pre-treatment to NF. Secondly, evaluations were carried out on the performance of two types of NF membranes (SR90 and NF90) in terms of permeate quality and fluxes for the investigated samples. The effect of cleaning on membrane performance was done. A reusability test was carried out on the permeate samples for dyeing. It was found that the use of UF as a pre-treatment yielded an increase in permeate of 5–25% of the NF fluxes and 90% in organics reduction for all treated samples, hence increasing the water recovery. High rejection of ˃90% by NF90 for COD, TOC and colour were obtained for all the treated samples. SR90 rejection was 80–90% for colour and ˃90% for COD and TOC. Salt recovery for NF90 was 60–90% and for SR90 was 40–50%. The reusability tests carried out showed that permeate recycled from NF90 can be used for any section in the textile industry including the most critical such as dyeing on light shades, while that from SR90 can be used for dyeing dark shades only. It was then concluded that membrane based processes can be integrated into the dye bath of the textile process for the purpose of reuse, thereby saving on the cost of chemicals (salts), reducing fresh water usage and reducing the extent of final effluent treatment.

International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Foundation Initiative 2010 (FI 2010) is a joint interoperability initiative of the Director, Operational Test and Evaluation. The vision of FI 2010 is to enable interoperability among ranges, facilities, and simulations in a timely and cost-efficient manner and to foster reuse of range assets and future range system developments. To achieve this vision, FI 2010 is developing and validating a common architecture with a common range object model, a core set of tools, inter-range communication capabilities, interfaces to existing range assets, interfaces to weapon systems, and recommended procedures for conducting synthetic test events and training exercises. During FY 01, the project is developing the second Test and Training ENabling Architecture (TENA) Middleware Prototype as a basis for range communication. FI 2010 will advance a simulation-based acquisition or a ‘distributed engineering plant’ methodology to streamline weapon system acquisition. Benefits from the FI 2010 products include cost effective replacement of customized data links, enhanced exchange of mission data, organic TENA-compliant capabilities at test sites to be leveraged for future test events, and instrumentation system reuse. Through FI 2010, future inter-range operations, instrumentation development, and range capability sustainment will cost less and incur less risk.

Οι υπάρχοντες μεταγλωττιστές, έχουν τρία βασικά μειονεκτήματα i) όλα τα υπό-προβλήματα της μεταγλώττισης (π.χ. μετασχηματισμοί, εύρεση χρονοπρογραμματισμού, ανάθεση καταχωρητών) βελτιστοποιούνται ξεχωριστά (εκτός από μεμονωμένες περιπτώσεις όπου βελτιστοποιούνται κάποια στάδια μαζί - συνήθως 2), παρόλο που υπάρχει εξάρτηση μεταξύ τους, ii) δεν εκμεταλλεύονται αποδοτικά όλα τα χαρακτηριστικά του προγράμματος εισόδου (π.χ. δομή του εκάστοτε αλγορίθμου, επαναχρησιμοποίηση δεδομένων), iii) δεν εκμεταλλεύονται αποδοτικά τις παραμέτρους της αρχιτεκτονικής. Στη παρούσα διδακτορική διατριβή, αναπτύχθηκαν μεθοδολογίες οι οποίες αντιμετωπίζουν τα προβλήματα εύρεσης χρονοπρογραμματισμών με τον ελάχιστο αριθμό i) προσβάσεων στην κρυφή μνήμη δεδομένων L1, ii) προσβάσεων στην κρυφή μνήμη L2, iii) προσβάσεων στην κύρια μνήμη, iv) πράξεων διευθυνσιοδότησης, μαζί σαν ενιαίο πρόβλημα και όχι ξεχωριστά, για ένα kernel. Αυτό επιτυγχάνεται αντιμετωπίζοντας τα χαρακτηριστικά του λογισμικού και τις τις βασικές παραμέτρους της αρχιτεκτονικής μαζί σαν ενιαίο πρόβλημα. Είναι η πρώτη φορά που μια μεθοδολογία αντιμετωπίζει τα παραπάνω προβλήματα με αυτό τον τρόπο. Οι προτεινόμενες μεθοδολογίες εκμεταλλεύονται τα χαρακτηριστικά του προγράμματος εισόδου. Η δομή του εκάστοτε αλγορίθμου (π.χ. ο FFT αποτελείται από πράξεις πεταλούδων ενώ ο αλγόριθμος αφαίρεσης θορύβου - Gauss Blur αποτελείται από πράξεις μάσκας στοιχείων), τα ιδιαίτερα χαρακτηριστικά του (π.χ. συμμετρία Toeplitz πίνακα), η ύπαρξη προτύπων-patterns (π.χ. στοιχεία πινάκων πολλαπλασιάζονται με μάσκα), η επαναχρησιμοποίηση των δεδομένων, η παραγωγή-κατανάλωση ενδιάμεσων αποτελεσμάτων και η παραλληλία του αλγορίθμου, αντιμετωπίζονται μαζί σαν ενιαίο πρόβλημα. Οι προτεινόμενες μεθοδολογίες εκμεταλλεύονται τις βασικές παραμέτρους της αρχιτεκτονικής. Η αρχιτεκτονική της μνήμης (π.χ. κοινή L2, L3), το πλήθος των καταχωρητών, ο αριθμός των κρυφών μνημών δεδομένων, τα μεγέθη, οι συσχετιστικότητες (assosiativity) και τα μεγέθη των γραμμών των κρυφών μνημών, ο αριθμός των λειτουργικών μονάδων, ο αριθμός των λειτουργικών μονάδων που λειτουργούν παράλληλα και ο αριθμός των πυρήνων (cores) του επεξεργαστή, αντιμετωπίζονται μαζί σαν ενιαίο πρόβλημα. Με την αξιοποίηση των χαρακτηριστικών του εκάστοτε αλγορίθμου και των παραμέτρων της αρχιτεκτονικής, αποκλείονται πιθανές λύσεις και ο χώρος εξερεύνησης μειώνεται ραγδαία (τάξεις μεγέθους). Στη παρούσα διδακτορική διατριβή, αναπτύχθηκαν μεθοδολογίες αύξησης της ταχύτητας του λογισμικού α) του Πολλαπλασιασμού Πίνακα επί Πίνακα (ΠΠΠ), β) του Πολλαπλασιασμού Πίνακα επί διάνυσμα (ΠΠΔ), γ) του Fast Fourier Transform (FFT), δ) του αλγορίθμου Canny και του μετασχηματισμού του Hough (αλγόριθμοι ανίχνευσης ακμών και ευθειών αντίστοιχα). Επίσης, αναπτύχθηκε μεθοδολογία μεταγλώττισης η οποία εκμεταλλεύεται τα χαρακτηριστικά του λογισμικού και τις παραμέτρους της ιεραρχίας μνήμης. Η μεθοδολογία μπορεί να εφαρμοστεί σε πυρήνες λογισμικού, στους οποίους α) τα μονοπάτια εκτέλεσης είναι γνωστά κατά τη μεταγλώττιση και συνεπώς δεν εξαρτώνται από τα δεδομένα, β) οι δείκτες όλων των sub- scripts να είναι γραμμικές εξισώσεις των iterators (που ισχύει στις περισσότερες περιπτώσεις). Οι μεθοδολογίες αφορούν ενσωματωμένους και γενικού σκοπού επεξεργαστές (χρήση μονάδας SIMD για περαιτέρω αύξηση της ταχύτητας). Ακολουθεί σύντομη περίληψη αυτών. Μεθοδολογία αύξησης της ταχύτητας του Πολλαπλασιασμού Πίνακα επί Πίνακα (ΠΠΠ): Αναπτύχθηκε μεθοδολογία αύξησης της ταχύτητας του ΠΠΠ για α) μονοπύρηνους επεξεργαστές (1 core), β) επεξεργαστές με πολλούς πυρήνες οι οποίοι συνδέονται με κοινή μνήμη. Η προτεινόμενη μεθοδολογία χωρίζει του πίνακες του αλγορίθμου σε μικρότερους οι οποίοι χωράνε στις κρυφές μνήμες και στο αρχείο καταχωρητών. Είναι η πρώτη φορά για τον ΠΠΠ που εισάγονται εξισώσεις οι οποίες αξιοποιούν τα associativities των κρυφών μνημών. Για τη πλήρη αξιοποίηση της ιεραρχίας της μνήμης προτείνεται νέος τρόπος αποθήκευσης των στοιχείων στη κύρια μνήμη (data array layout). Επίσης, προτείνεται διαφορετικός χρονοπρογραμματισμός σε επίπεδο στοιχείων και σε επίπεδο υπό-πινάκων. Η προτεινόμενη μεθοδολογία επιτυγχάνει από 1.1 έως 3.5 φορές μικρότερο χρόνο εκτέλεσης από τη βιβλιοθήκη του ATLAS, η οποία αποτελεί μια από τις ταχύτερες βιβλιοθήκες. Μεθοδολογία αύξησης της ταχύτητας του Fast Fourier Transform (FFT): Αναπτύχθηκε μεθοδολογία αύξησης της ταχύτητας του FFT αξιοποιώντας πλήρως τα ιδιαίτερα χαρακτηριστικά του αλγορίθμου και τις παραμέτρους της ιεραρχίας της μνήμης. Το διάγραμμα ροής δεδομένων (Data Flow Graph – DFG) του FFT, χωρίζεται σε πρότυπα (patterns) και σε υπό- FFTs. Κάθε πρότυπο, αποτελείται από πεταλούδες, σύμφωνα με το πλήθος των καταχωρητών του επεξεργαστή. Η επιλογή των πεταλούδων κάθε προτύπου έχει γίνει με τέτοιο τρόπο ώστε να μεγιστοποιείται η παραγωγή-κατανάλωση των ενδιάμεσων αποτελεσμάτων. Η σειρά εκτέλεσης των προτύπων είναι αυτή η οποία δίνει τη μέγιστη επαναχρησιμοποίηση των συντελεστών του FFT. Ο DFG του FFT χωρίζεται σε υπό-FFTs σύμφωνα με τον αριθμό και τα μεγέθη των κρυφών μνημών δεδομένων. Η προτεινόμενη μεθοδολογία δίνει από 1.1 μέχρι 1.8 φορές μικρότερο χρόνο εκτέλεσης από τη βιβλιοθήκη του FFTW, η οποία παρέχει ταχύτατο χρόνο εκτέλεσης. Είναι η πρώτη φορά για τον FFT που μια μεθοδολογία λαμβάνει υπόψη τις παραμέτρους της ιεραρχίας μνήμης και του αρχείου καταχωρητών. Μεθοδολογία αύξησης της ταχύτητας του Πολλαπλασιασμού Πίνακα επί Διάνυσμα (ΠΠΔ) για Toeplitz, Bisymetric (BT), Toeplitz (Τ) και κανονικούς πίνακες: Αναπτύχθηκε μεθοδολογία αύξησης της ταχύτητας του ΠΠΔ. Οι παραπάνω πίνακες έχουν ιδιαίτερη δομή, μικρό αριθμό διαφορετικών στοιχείων και μεγάλη επαναχρησιμοποίηση, χαρακτηριστικά τα οποία αξιοποιούνται πλήρως. Η προτεινόμενη μεθοδολογία χωρίζει τους πίνακες του αλγορίθμου σε μικρότερους οι οποίοι χωράνε στις κρυφές μνήμες και στο αρχείο καταχωρητών σύμφωνα με τον αριθμό τα μεγέθη και τα associativities των κρυφών μνημών. Για τη πλήρη αξιοποίηση της ιεραρχίας μνήμης προτείνεται νέος τρόπος αποθήκευσης των στοιχείων του πίνακα (data array layout) στη κύρια μνήμη. Η προτεινόμενη μεθοδολογία χρησιμοποιεί τον κανονικό αλγόριθμο ΠΠΔ (γραμμή επί στήλη). Ωστόσο, για BT και T πίνακες, ο ΠΠΔ μπορεί να υλοποιηθεί με χρήση του FFT επιτυγχάνοντας μικρότερη πολυπλοκότητα για μεγάλα μεγέθη πινάκων (έγινε ανάλυση και σύγκριση των δύο αλγορίθμων θεωρητικά και πειραματικά). Η προτεινόμενη μεθοδολογία για κανονικούς πίνακες συγκρίνεται με τη βιβλιοθήκη του ATLAS, επιτυγχάνοντας από 1.2 μέχρι 4.4 φορές μικρότερο χρόνο εκτέλεσης. Μεθοδολογία αύξησης της ταχύτητας του αλγόριθμου ανίχνευσης ακμών και ευθειών (αλγόριθμος του Canny και μετασχηματισμός του Hough): Αναπτύχθηκε μεθοδολογία η οποία επιτυγχάνει i) μικρότερο αριθμό εντολών ανάγνωσης/εγγραφής και διευθυνσιοδότησης, ii) μικρότερο αριθμό προσβάσεων και αστοχιών στην ιεραρχία μνήμης και iii) μικρότερο μέγεθος απαιτούμενης μνήμης του αλγορίθμου, εν συγκρίσει με την βιβλιοθήκη OpenCV η οποία παρέχει ταχύτατο χρόνο εκτέλεσης στους αλγορίθμους επεξεργασίας εικόνων. Τα παραπάνω επιτυγχάνονται: α) αξιοποιώντας την παραγωγή-κατανάλωση των στοιχείων των πινάκων και την παραλληλία του αλγορίθμου - τα τέσσερα kernels του Canny συγχωνεύονται σε ένα, διασωληνώνοντας (pipelining) τους πυρήνες για να διατηρηθούν οι εξαρτήσεις των δεδομένων, β) μειώνοντας τον αριθμό και το μέγεθος των πινάκων, γ) γράφοντας τα δεδομένα σε νέους μειωμένων διαστάσεων πίνακες με κυκλικό τρόπο, δ) χωρίζοντας τους πίνακες σε μικρότερους οι οποίοι χωράνε στο αρχείο καταχωρητών και στη κρυφή μνήμη δεδομένων σύμφωνα με το μέγεθος των κρυφών μνημών και του associativity, ε) βρίσκοντας τον βέλτιστο τρόπο αποθήκευσης των πινάκων (data array layout) στην κύρια μνήμη σύμφωνα με τη συσχετιστικότητα (associativity) της κρυφής μνήμης. Η προτεινόμενη μεθοδολογία δίνει από 1.27 μέχρι 2.2 φορές μικρότερο χρόνο εκτέλεσης από τη βιβλιοθήκη OpenCV (αναπτύχθηκε από την Intel και είναι γραμμένη σε χαμηλό επίπεδο), η οποία παρέχει ταχύτατο χρόνο εκτέλεσης. Μεθοδολογία μεταγλώττισης: Αναπτύχθηκε μεθοδολογία μεταγλώττισης η οποία αντιμετωπίζει τα προβλήματα εύρεσης χρονοπρογραμματισμών με τον ελάχιστο αριθμό i) προσβάσεων στην κρυφή μνήμη δεδομένων L1, ii) προσβάσεων στην κρυφή μνήμη L2, iii) προσβάσεων στην κύρια μνήμη, iv) πράξεων διευθυνσιοδότησης, μαζί σαν ενιαίο πρόβλημα και όχι ξεχωριστά, για ένα kernel. Η προτεινόμενη μεθοδολογία λαμβάνει ως είσοδο ker- nels σε C-κώδικα και παράγει νέα επιτυγχάνοντας είτε υψηλή απόδοση είτε τον ελάχιστο αριθμό προσβάσεων σε δεδομένη μνήμη. Αρχικά βρίσκεται ο χώρος εξερεύνησης με βάση τα χαρακτηριστικά του λογισμικού. Ο χώρος εξερεύνησης περιγράφεται από μαθηματικές εξισώσεις και ανισότητες οι οποίες προέρχονται από τα subscripts των πινάκων, τους iterators, τα όρια των βρόχων και τις εξαρτήσεις των δεδομένων. Αυτός ο χώρος εξερεύνησης δεν μπορεί να παραχθεί με την εφαρμογή υπαρχόντων μετασχηματισμών στον αρχικό C-κώδικα. Κατόπιν, ο χώρος εξερεύνησης μειώνεται τάξεις μεγέθους εφαρμόζοντας διάδοση περιορισμών (constraint propagation) των παραμέτρων του λογισμικού και αυτών της αρχιτεκτονικής της μνήμης. Το αρχείο καταχωρητών (register file) και τα μεγέθη των κρυφών μνημών αξιοποιούνται πλήρως παράγοντας ανισότητες για κάθε μνήμη οι οποίες περιέχουν α) τα μεγέθη των tiles που απαιτούνται για κάθε πίνακα, β) το σχήμα κάθε tile. Επίσης, βρίσκεται ο βέλτιστος τρόπος αποθήκευσης των στοιχείων των πινάκων στη κύρια μνήμη, σύμφωνα με τη συσχετιστικότητα (associativity) των κρυφών μνημών. Η προτεινόμενη μεθοδολογία εφαρμόστηκε σε 5 ευρέως διαδεδομένους αλγορίθμους και επιτυγχάνει αύξηση της ταχύτητας (speedup) από 2 έως 18 φορές (έγινε σύγκριση του αρχικού C κώδικα και του C κώδικα έπειτα από την εφαρμογή της προτεινόμενης μεθοδολογίας – η μεταγλώττιση έγινε με τον gcc compiler). / The existing state of the art (SOA) compilers, have 3 major disadvantages. Firstly, the back-end compiler phases - subproblems (e.g. transformations, scheduling, register allocation) are optimized separately; these subproblems depend on each other and they should be optimized together as one problem and not separately. Secondly, the existing SOA compilers do not effectively utilize the software characteristics (e.g. algorithm structure, data reuse). Thirdly, they do not effectively utilize the hardware parameters. In this PhD dissertation, new methodologies have been developed speeding up software kernels, by solving the sub-problems of finding the schedules with the minimum numbers of i) L1 data cache accesses, ii) L2 data cache accesses, iii) main memory accesses and iv) addressing instructions, as one problem and not separately. This is achieved by fully exploiting the software information and the memory hierarchy parameters. This is the first time a methodology optimizes the above sub-problems in this way. The proposed methodologies fully utilize the software characteristics. The algorithm structure (e.g. FFT data flow graph consists of butterfly operations while the gauss blur algorithm consists of array mask operations), the algorithm individual characteristics (e.g. symmetry of Toeplitz matrix), the data patterns (e.g. matrix elements are multiplied by a mask), data reuse, production-consumption of intermediate results and algorithm's parallelism, are utilized as one problem and not separately. The proposed methodologies fully utilize the major architecture parameters. The memory archi- tecture (e.g. shared L2/L3 cache), the size of the register file, the number of the levels of data cache hierarchy, the data cache sizes, the data cache associativities, the data cache line sizes, the number of the function units, the number of the function units can run in parallel and the number of the CPU cores are utilized as one problem and not separately. By utilizing the hardware and software constraints the exploration space is orders of magnitude decreased. In this PhD dissertation, new speeding-up methodologies are developed for i) Matrix Matrix Multi- plication (MMM) algorithm, ii) Matrix Vector Multiplication (MVM) algorithm, iii) Fast Fourier Trans- form (FFT), iv) Canny algorithm and Hough Transform. Also, a new compilation methodology which fully exploits the memory architecture and the software characteristics, is developed. This methodology can be applied in software kernels whose i) execution paths are known at compile time and thus they do not depend on the data, ii) all array subscripts are linear equations of the iterators (which in most cases do). The above methodologies refer to both embedded and general purpose processors (usage of the SIMD technology). The summary of the above methodologies is given below. A Methodology for speeding-up Matrix Matrix Multiplication (MMM) algorithm: A new methodol- ogy for Matrix Matrix Multiplication using SIMD (Single Instruction Multiple Data) unit and not, at one and more cores having a shared cache, is presented. The proposed methodology partitions the MMM matrices into smaller sub-matrices fitting in the data cache memories and into register file according to the memory hierarchy architecture parameters. This is the first time for MMM algorithm that equations containing the data cache associativity values, are given. To fully utilize the memory hierarchy, a new the data array layout is proposed. The proposed methodology is from 1.1 up to 3.5 times faster than one of the SOA software libraries for linear algebra, ATLAS. A Fast Fourier Transform (FFT) speeding-up methodology: A new Fast Fourier Transform method- ology is presented which fully utilizes the individual algorithm characteristics and the memory hierarchy architecture parameters. FFT data flow graph (DFG) is partitioned into patterns and into sub-FFTs. Each pattern consists of butterflies according to the number of the registers. The selection of the exact butter- flies each pattern contains, has been made by maximizing the production-consumption of the butterflies intermediate results. Also, the patterns are executed in that order, minimizing the data reuse of the FFT twiddle factors. The FFT data flow graph is partitioned into sub-FFTs according to the number of the levels and the sizes of data cache. The proposed methodology is faster from 1.1 up to 1.8 times in con- trast to the SOA FFT library, FFTW. This is the first time that an FFT methodology fully utilizes the memory hierarchy architecture parameters. A methodology for speeding-up Matrix Vector Multiplication (MVM) algorithm for regular, Toeplitz and Bisymmetric Toeplitz matrices: A new methodology for MVM including different types of matrices, is presented. The above matrices have a special structure, a small number of different elements and large data reuse. The proposed methodology partitions the MVM matrices into smaller sub-matrices fitting in the data cache memories and into register file according to the memory hierarchy architecture parameters. To fully utilize the memory hierarchy, a new data array layout is proposed. The proposed methodology uses the standard algorithm for matrix vector multiplication, i.e. each row of A is multiplied by X. However, for Bisymmetric Toeplitz (BT) and Toeplitz (T) matrices, MVM can also be implemented by using FFT; although in this paper we use the standard MVM algorithm, we show that for large input sizes, the MVM using FFT performs much better. The proposed methodology achieves speedup from 1.2 up to 4.4 over the SOA libraries, ATLAS. A Methodology for Speeding Up Edge and Line Detection Algorithms: A new Methodology for Speeding Up Edge and Line Detection Algorithms focusing on memory architecture utilization is pre- sented. This methodology achieves i) a smaller number of load/store and arithmetic instructions, ii) a smaller number of data cache accesses and data cache misses in memory hierarchy and iii) a smaller algorithm memory size, in contrast to the SOA library of OpenCV. This is achieved by: i) utilizing the production-consumption of intermediate results - merging all Canny kernels to one and pipelining the kernels to comply with the data dependences, ii) reducing the number and the size of the arrays, iii) writing the data into the new reduced size arrays in a circular way, iv) applying loop tiling for the register file and data cache, according to the size of the memories and associativity and v) finding the data arrays layout according to the data cache associativity. The proposed methodology achieves speedup from 1.27 up to 2.2 over the OpenCV SOA library. Compilation methodology: A new compilation methodology which fully exploits the memory archi- tecture and the software characteristics is presented. This is the first time that a methodology optimizes the subproblems explained above as one problem and not separately, for a loop-kernel. The proposed methodology takes as input C-code kernels and it produces new software kernels with a new iteration space, which may not be given by applying existing compiler transformations to original code. Firstly, the exploration space is found according to the s/w characteristics; it is described by mathematical equations and inequalities that are derived from the array subscripts, the combination of common array references, loop iterators, loop bounds and data dependences. Then, the exploration space is orders of magnitude decreased by applying constraint propagation of the h/w and s/w parameters. The register file and the data cache sizes are fully exploited by producing register file and data cache inequalities which contain i) the tiles sizes of each array, ii) the shape of each array tile. Also, new data array layouts are found, according to the data cache associativity. The final schedule is found by choosing the best combination of the number of i) L1 data cache accesses, ii) L2 data cache accesses, iii) main memory data accesses and iv) addressing instructions. The proposed methodology is evaluated to five well-known algorithms and speedups from 2 up to 18 over the target gcc compiler are obtained.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management