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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

A comparative study of automatic text summarization using human evaluation and automatic measures / En jämförande studie av automatisk textsammanfattning med användning av mänsklig utvärdering och automatiska mått

Wennstig, Maja January 2023 (has links)
Automatic text summarization has emerged as a promising solution to manage the vast amount of information available on the internet, enabling a wider audience to access it. Nevertheless, further development and experimentation with different approaches are still needed. This thesis explores the potential of combining extractive and abstractive approaches into a hybrid method, generating three types of summaries: extractive, abstractive, and hybrid. The news articles used in the study are from the Swedish newspaper Dagens Nyheter(DN). The quality of the summaries is assessed using various automatic measures, including ROUGE, BERTScore, and Coh-Metrix. Additionally, human evaluations are conducted to compare the different types of summaries in terms of perceived fluency, adequacy, and simplicity. The results of the human evaluation show a statistically significant difference between attractive, abstractive, and hybrid summaries with regard to fluency, adequacy, and simplicity. Specifically, there is a significant difference between abstractive and hybrid summaries in terms of fluency and simplicity, but not in adequacy. The automatic measures, however, do not show significant differences between the different summaries but tend to give higher scores to the hybrid and abstractive summaries
92

Study on conversion of some chemical compounds of wood sawdust waste in biocomposting process: Research article

Nguyen, Thi Minh Nguyet, Chu, Thi Thu Ha 15 November 2012 (has links)
This paper presents the research results of treatment solution of wood waste of Acacia and Eucalyptus in making of bioorganic fertilizers for the effective utilization of plant biomass resources and minimization of environmental pollution. The conversion cycles of the basic chemical compounds of wood waste in composting process were established by two biological products: Biomix and Compost Maker. Research results have shown that, under the action of microorganisms, all basic chemical compounds were modified (among them cellulose was most powerfully modified) whereas lignin, extractives dissolved in ethanol were less destructed. Within about first 75 days of composting, the conversion of the above mentioned compounds is negligible. With the time of composting from 105 days to 120 days, in total over of 70% of cellulose was conversed into compounds dissolved in water and in 1% NaOH solution. The optimal composting time was about 105 days. In this case, the fertilizer obtained was humified, had dark colour and could be used for planting and soil improvement purposes. / Bài báo này trình bày các kết quả nghiên cứu giải pháp xử lý mùn vụn gỗ phế thải của gỗ Keo và Bạch đàn thành phân bón hữu cơ vi sinh, nhằm tận dụng hiệu quả nguồn sinh khối thực vật và giảm thiểu ô nhiễm môi trường. Đã xác lập được một số quy luật biến đổi của các thành phần hóa học cơ bản của mùn vụn gỗ trong quá trình ủ compost bằng hai chế phẩm vi sinh Biomix và Compost Maker, để tạo phân bón hữu cơ vi sinh. Kết quả nghiên cứu đã cho thấy, dưới tác dụng của vi sinh vật, tất cả các thành phần hóa học cơ bản của mùn vụn gỗ đều bị biến đổi, trong đó xenluloza bị biến đổi mạnh nhất, lignin và các chất trích ly bằng etanol ít bị phân hủy hơn. Trong vòng khoảng 75 ngày ủ đầu tiên, sự biến đổi của các thành phần nêu trên là không đáng kể. Với thời gian ủ từ 105 ngày đến 120 ngày, tổng cộng có trên 70% xenluloza bị phân hủy thành các hợp chất dễ tan trong nước và dung dịch NaOH 1%. Thời gian ủ thích hợp là khoảng 105 ngày. Trong trường hợp này, phân bón thu được đã bị mùn hóa, có mầu sẫm và có thể sử dụng cho mục đích trồng trọt và cải tạo đất.
93

Techno-economic Analysis of Continuous Ester Technology: Production of Glycerol Trivalerate and Propyl Acetate

Isberg, Gustav January 2024 (has links)
Organic esters are an important class of industrial and commercial chemicals that can be found in solvents, plasticizer, food flavours, detergents, agrochemicals, and pharmaceuticals. The most common way to synthesis organic esters is with esterification or transesterification. Where esterification was the chosen method in this thesis.  This thesis provides a techno-economic assessment on the production of propyl acetate and glycerol trivalerate through different continuous routes that is than compared with batch production under the same conditions. Simulations was done on trivalerate due to limited literature and data on pentaerythritol tetravalerate. Different continuous technologies that have been assessed in this thesis was plug flow reactor (PFR), Reactive Distillation (RD), and Reactive – Extractive Distillation (RED). The production of mono- and polyol esters with different unit operators was simulated in Aspen Plus V.14. Techno-Economic analysis was conducted with APEA (Aspen Process Economic Analyzer), where cost of raw materials, products, and utilities was inserted to evaluate annual operating cost and product sale. Reaction kinetic for esterification of trivalerate was estimated by obtained values from simulations of a Gibbs reactor in Aspen Plus at four different temperatures. Kinetics was estimated by applying the relation between the chemical equilibrium constant and the Arrhenius equation. Where rate constant and activation energy for forward and revers reaction was obtained by varying min and max values for lsqcurvefit in MATLAB and then validate results with published kinetics.  Results from production of propyl acetate with batch, PFR and RED provides an annual profit of approximately 1 M$ at a capacity of 41.65 kton/year. The three different process provides also approximately an equal capital cost, operating cost, equipment cost, and installed cost according to APEA. RED provided the lowest propyl acetate yield at 93%, batch and PFR provided a propyl acetate yield of 94%.  Results from production of trivalerate with batch, PFR, and RD provides an annual profit of 5.4, 5.78, and 9.2 M$ at a capacity of approximately 5 kton/year. Where RD process provides the lowest capital cost, operating cost, equipment cost, and installed cost compared to batch and PFR processes according to APEA. Obtained results from production of trivalerate can be used to evaluate the economic and technical feasibility of a continuous production plant for pentaerythritol tetravalerate (PETV). Where initial simulations show a good economic and technical viability of a continuous ester production plant.
94

Extractive Violence on Indigenous Country : sami and Aboriginal Views on Conflicts and Power Relations with Extractive Industries / Extraktivt våld på urfolks marker : konflikter och maktrelationer mellan utvinningsindustrier och urfolk i Sverige och Australien

Sehlin MacNeil, Kristina January 2017 (has links)
Asymmetrical conflicts and power relations between extractive industries and Indigenous groups often have devastating consequences for Indigenous peoples. Many Indigenous groups are struggling to maintain their lands as Indigenous perspectives on connection to Country are frequently undervalued or dismissed in favour of extractivist ideologies. While this conflicted interface has been researched in various parts of the world, studies exploring conflicts and power relations with extractive industries from Indigenous perspectives are few. This thesis is an international comparison aiming to illuminate situations of conflict and asymmetrical power relations caused by extractivism on Indigenous lands from new viewpoints. By drawing on two single case studies, the situations for Laevas reindeer herding Sami community in northern Sweden and Adnyamathanha Traditional Owners in South Australia are compared and contrasted. Yarning (a form of interviewing) is used as a method for data collection and in order to stay as true as possible to the research participants’ own words a number of direct quotes are used. The analysis employs peace researcher Johan Galtung’s concepts of cultural and structural violence as analytical tools to further explore the participants’ experiences of interactions with extractive industries and industrial proponents, including governments. In addition, the thesis introduces the concept of extractive violence as a complement to Galtung’s model. Extractive violence is defined as a form of direct violence against people and/or animals and nature caused by extractivism, which predominantly impacts peoples closely connected to land. The concepts of structural and cultural violence are understood as unjust societal structures and racist and discriminating attitudes respectively. A number of main themes could be identified in the research participants’ narratives. However, the most prominent on both continents was connections to Country and the threat that extractive violence posed to these connections. The results show that although the expressions of cultural, structural and extractive violence experienced by the two Indigenous communities varied, the impacts were strikingly similar. Both communities identified extractive violence, supported by structural and cultural violence, as threats to the continuation of their societies and entire cultures. Furthermore, the results suggest that in order to address violence against Indigenous peoples and achieve conflict transformation, Indigenous and decolonising perspectives should be heard and taken into account. / Konflikter och maktrelationer mellan utvinningsindustrier och urfolksgrupper får ofta förödande konsekvenser för urfolken. På grund av assymetriska maktförhållanden mellan urfolk och majoritetssamhällen som råder på de flesta ställen i världen utsätts många urfolk systematiskt för rättighetskränkningar. Många urfolksgrupper kämpar idag för att bevara sina marker eftersom urfolks perspektiv och kopplingar till marken ofta förminskas eller ignoreras när de står i motsättning till extraktiva ideologier. Även om extraktivism och påverkan på urfolk och urfolksgrupper varit fokus för tidigare studier saknas forskning som utgår från urfolkens perspektiv. Denna avhandling är en internationell jämförelse med syfte att, från nya synvinklar, belysa konfliktsituationer och asymmetriska maktrelationer som orsakats av extraktivism på urfolks marker. Avhandlingen jämför och kontrasterar två fallstudier som utförts med Laevas č earru (sameby) i norra Sverige och Adnyamathanha-folket i delstaten South Australia. I fallstudien som utförts tillsammans med Laevas č earru ingår en grupp av totalt sex forskningsdeltagare, fyra män och två kvinnor. Det var dock framför allt två forskningsdeltagare som intervjuades med anledning av den konfliktsituation mellan Laevas č earru och gruvbolaget LKAB, som står i fokus för artikel I i avhandlingen. I den australiska fallstudien, som utförts tillsammans med Adnyamathanha-folket, ingår en grupp av sju forskningsdeltagare bestående av fyra kvinnor och tre män. Denna studie, artikel II, behandlar Adnyamathanhafolkets kamp mot de australiska och sydaustraliska regeringarnas förslag om att inrätta kärnavfallsdepåer på Adnyamathanhas marker. För att inhämta material användes yarning (en typ av intervjumetod) och för att återge forskningsdeltagarnas ord så rättvisande möjligt inkluderades ett antal direktcitat i texterna. För att möjliggöra en mer djupgående analys av forskningsdeltagarnas upplevelser av konflikter med utvinningsindustrier och förespråkare för extraktivism, inklusive regeringar och stater, användes Johan Galtungs modell, känd som Galtungs våldstriangel, som analysverktyg. Galtungs modell innefattar strukturellt, kulturellt och direkt våld. Direkt våld definieras som fysiskt våld eller hot om fysiskt våld, strukturellt våld utgörs av orättvisa och diskriminerande samhällsstrukturer och kulturellt våld är de attityder som får det strukturella och således även det direkta våldet att te sig legitimt. Föreliggande avhandling introducerar även konceptet extraktivt våld som ett komplement till Galtungs modell där xvi det ersätter direkt våld. Jag definierar extraktivt våld som en typ av direkt våld mot människor och/eller djur och natur orsakat av extraktivism som framför allt påverkar människor med starka kopplingar till sina marker. Extraktivism förstås här som alla typer av aktiviteter som extraherar stora mängder av resurser från marker och människor, exempelvis gruvdrift, skogsbruk, fiske, lantbruk och turism. I forskningsdeltagarnas utsagor identifierades ett antal nyckelteman. Dessa teman uppvisade både likheter och skillnader beroende på deltagarnas olika situationer och förutsättningar. Det mest framträdande temat på båda kontinenterna var dock ”connection to Country” eller kopplingar till marken. Båda grupperna beskrev hur marken och deras förhållande till den innefattade historia, kunskap, traditioner och kultur. För Adnyamathanhagruppen var det mest centrala att rädda och bevara heliga platser som hotas av extraktivism och för Laevas č earru sågs renskötseln och bevarandet av markerna för renarnas skull som det mest väsentliga. Avhandlingens resultat visar att även om de former av kulturellt, strukturellt och extraktivt våld som forskningsdeltagarna upplevde varierade, var effekterna av våldet slående lika. Båda grupperna identifierade extraktivt våld, understött av strukturellt och kulturellt våld, som hot mot fortlevnaden av deras samhällen och kulturer. Resultaten pekar även på vikten av att urfolkens perspektiv inkluderas och blir hörda om konflikttransformering mellan utvinningsindustrier och urfolk ska kunna uppnås.
95

Extension of thermodynamic insights on batch extractive distillation to continuous operation / Conception des procédés de distillation extractive continue basée sur des critères de faisabilité thermodynamique de la distillation extractive discontinue

Shen, Weifeng 21 September 2012 (has links)
Nous étudions la faisabilité du procédé de distillation extractive continue pour séparer des mélanges azéotropiques A-B à température de bulle minimale ou maximale, avec un tiers corps E lourd ou léger. Les mélanges ternaires A-B-E appartiennent aux classes 1.0-1-a et 1.0-2 qui se subdivisent chacune en deux souscas selon la position de la courbe d'univolatilité. La colonne de distillation a trois sections, rectification, extractive, épuisement. Nous établissons les équations décrivant les profiles de composition liquide dans chaque section en fonction des paramètres opératoires: pureté et taux de récupération du distillat, taux de reflux ratio R et rapport des débits d'alimentation FE/F dans le cas d'un tiers corps lourd ; pureté et taux de récupération du produit de pied, taux de rebouillage S et rapport des débits d'alimentation FE/F dans le cas d'un tiers corps léger. Avec un tiers corps lourd alimenté comme liquide bouillant au dessus de l'étage d'alimentation du mélange A-B, nous identifions le distillat atteignable et les plages de valeurs faisables des paramètres R et FE/F à partir du critère général de faisabilité énoncé par Rodriguez-Donis et al. (Ind. Eng. Chem. Res, 2009, 48(7), 3544–3559). Pour la classe 1.0-1a, il existe des rapport FE/F et reflux ratio minimum. Le rapport FE/F est plus important pour le procédé continu que pour le procédé discontinu parce que la faisabilité du procédé continu nécessite que les profils d'épuisement et extractifs s'intersectent. Pour la classe 1.0-2, les deux constituants A et B sont des distillats potentiels, l'un sous réserve que le rapport FE/F reste inférieur à une valeur limite maximale. Le procédé continu exhibe également une valeur minimale de FE/F à un taux de reflux ratio donné, contrairement au procédé discontinu. Avec un tiers corps léger alimenté comme vapeur saturante sous l'étage d'alimentation du mélange A-B, nous identifions le produit de pied atteignable et les plages de valeurs faisables des paramètres S et FE/F à partir du critère général de faisabilité énoncé par Rodriguez-Donis et al. (Ind. Eng. Chem. Res, 2012, 51, 4643–4660). Comparé au cas des tiers corps lourds, le produit principal est obtenu en pied. Autrement, les comportements des classes 1.0-1a et 1.0-2 sont analogues entre les tiers corps léger et lourd. Avec un tiers corps léger, le procédé continu ajoute la contrainte que les profils de rectification et extractifs s'intersectent. La contrainte d'intersection des profils d'épuisement et extractif est partagée par les deux modes opératoires continu et discontinu. Ce travail valide la méthodologie proposée pour évaluer la faisabilité du procédé de distillation extractive continue et permet de comparer les tiers entre eux en termes de taux de reflux ratio minimum et de rapport de débit d'alimentation minimal / We study the continuous extractive distillation of minimum and maximum boiling azeotropic mixtures A-B with a heavy or a light entrainer E, intending to assess its feasibility based on thermodynamic insights. The ternary mixtures belong to the common 1.0-1a and 1.0-2 class ternary diagrams, each with two sub-cases depending on the univolatility line location. The column has three sections, rectifying, extractive and stripping. Differential equations are derived for each section composition, depending on operating parameters: distillate product purity and recovery, reflux ratio R and entrainer – feed flow rate ratio FE/F for the heavy case; bottom product purity and recovery, reboil ratio and entrainer – feed flow rate ratio for the light entrainer case. For the case with a heavy entrainer fed as a boiling liquid above the main feed, the feasible product and operating parameters R and FE/F ranges are assessed under infinite reflux ratio conditions by using the general feasibility criterion enounced by Rodriguez-Donis et al. (Ind. Eng. Chem. Res, 2009, 48(7), 3544–3559). For the 1.0-1a class, there exists a minimum entrainer - feed flow rate ratio to recover the product, and also a minimum reflux ratio. The minimum entrainer - feed flow rate ratio is higher for the continuous process than for the batch because of the additional requirement in continuous mode that the stripping profile intersects with the extractive profile. For the 1.0-2 class both A and B can be distillated. For one of them there exists a maximum entrainer - feed flow rate ratio. The continuous process also has a minimum entrainer - feed flow rate ratio limit for a given feasible reflux ratio. For the case with a light entrainer fed as saturated vapor below the main feed, the feasible product and operating parameters S and FE/F ranges are assessed under infinite reflux ratio conditions by using the general feasibility criterion enounced by Rodriguez-Donis et al. (Ind. Eng. Chem. Res, 2012, 51, 4643–4660), Compared to the heavy entrainer case, the main product is removed from the column bottom. Similar results are obtained for the 1.0-1a and 1.0-2 class mixtures whether the entrainer is light or heavy. With a light entrainer, the batch insight about the process feasibility holds for the stripping and extractive sections. Now, an additional constraint in continuous mode comes from the necessary intersection between the rectifying and the extractive sections. This work validates the proposed methodology for assessing the feasibility of continuous extractive distillation processes and enables to compare entrainers in terms of minimum reflux ratio and minimum entrainer feed flow rate ratio
96

L'évaluation comptable des réserves et ressources des entreprises de l'industrie extractive / The accounting valuation of reserves and resources of companies in the extractive industry / La evaluación contable de las reserves y los recursos de las empresas de la industria de extracción

Orellana Fuentes, Claudia Alejandra 14 January 2014 (has links)
Cette recherche apporte une contribution à la problématique de l'évaluation économique et comptable des actifs de réserves et de ressources de l'industrie extractive. Elle vise à répondre à la question suivante: Quelles sont les valeurs économiques des réserves et des ressources qui sont appréhendées par la comptabilité d'entreprise et quelles sont, en cas de choix entre plusieurs types de valeurs, les raisons de ces choix?Elle montre dans sa première partie qu'il n'existe qu'une correspondance partielle entre les valeurs économiques et les valeurs comptables, ce qui privilégie la théorie économique néoclassique. Elle montre dans sa deuxième partie que diverses méthodes comptables cohabitent au sein des six pays étudiés en considération des intérêts des entreprises majors et juniors de cette industrie. La troisième partie de la thèse analyse le processus de normalisation de l'IASB et souligne l'influence du pouvoir des majors et l'influence indirecte exercée par les juniors. Cette thèse s'inscrit dans le prolongement de la recherche en comptabilité critique. / This research contributes to the problem of economic and accounting valuation of the assets reserves and resources in the extractive industry. It aims to answer the following question: What are the economic values of reserves and resources that are recognized by corporate accounting and what are, in cas of a choice between several types of values, the reasons for these choices? It shows in the first part there is only partial matching between economic values and accounting values that favors neoclassical economic theory. It shows, in the second part, that different accounting methods coexist in the six countries studied, taking int consideration the interests of majors and juniors companies in this industry. The third part of the thesis analyzes the IASB's standard-setting process and underlines the influence of the majors power and the indirect influence of the juniors. This thesis is a continuation of research in critical accounting. / Esta investigación aporta una contribución a la problemática de la evaluación económica y contable de los activos reservas y recursos de la industria de extracción. Su objetivo es responder a la siguiente pregunta: ¿Cuáles son los valores económicos de las reservas y los recursos que son reconocidos por la contabilidad de empresas y cuáles son, en el caso de escoger entre varios tipos de valores , las razones de estas decisiones? En la primera parte se demuestra que sólo hay correspondencia parcial entre los valores económicos y los valores de contables, lo que favorece la teoría económica neoclásica. En la segunda parte se demuestra que diversos métodos de contabilidad coexisten en los seis países estudiados tomando en cuenta los intereses de las empresas majors y las empresas juniors de esta industria. La tercera parte de la tesis analiza el proceso de normalización del IASB y subraya la influencia del poder de las grandes multinacionales y la influencia indirecta de los juniors. Esta tesis es una continuación de la investigación en contabilidad crítica.
97

Information Theoretic Approach To Extractive Text Summarization

Ravindra, G 08 1900 (has links)
Automatic text summarization techniques, which can reduce a source text to a summary text by content generalization or selection have assumed signifi- cance in recent times due to the ever expanding information explosion created by the World Wide Web. Summaries generated by generalization of information are called abstracts and those generated by selection of portions of text (sentences, phrases etc.) are called extracts. Further, summaries could for each document separately or multiple documents could be summarized together to produce a single summary. The challenges in making machines generate extracts or abstracts are primarily due to the lack of understanding of human cognitive processes. Summary generated by humans seems to be influenced by their moral, emotional and ethical stance on the subject and their background knowledge of the content being summarized.These characteristics are hardly understood and difficult to model mathematically. Further automatic summarization is very much handicapped by limitations of existing computing resources and lack of good mathematical models of cognition. In view of these, the role of rigorous mathematical theory in summarization has been limited hitherto. The research reported in this thesis is a contribution towards bringing in the awesome power of well-established concepts information theory to the field of summarization. Contributions of the Thesis The specific focus of this thesis is on extractive summarization. Its domain spans multi-document summarization as well as single document summarization. In the whole thesis the word "summarization" and "summary", imply extract generation and sentence extracts respectively. In this thesis, two new and novel summarizers referred to as ESCI (Extractive Summarization using Collocation Information) and De-ESCI (Dictionary enhanced ESCI) have been proposed. In addition, an automatic summary evaluation technique called DeFuSE (Dictionary enhanced Fuzzy Summary Evaluator) has also been introduced.The mathematical basis for the evolution of the scoring scheme proposed in this thesis and its relationship with other well-known summarization algorithms such as latent Semantic Indexing (LSI) is also derived. The work detailed in this thesis is specific to the domain of extractive summarization of unstructured text without taking into account the data set characteristics such as the positional importance of sentences. This is to ensure that the summarizer works well for a broad class of documents, and to keep the proposed models as generic as possible. Central to the proposed work is the concept of "Collocation Information of a word", its quantification and application to summarization. "Collocation Information" (CI) is the amount of information (Shannon’s measure) that a word and its collocations together contribute to the total information in the document(s) being summarized.The CI of a word has been computed using Shannon’s measure for information using a joint probability distribution. Further, a base value of CI called "Discrimination Threshold" (DT) has also been derived. To determine DT, sentences from a large collection of documents covering various topics including the topic covered by the document(s) being summarized were broken down into sequences of word collocations.The number of possible neighbors for a word within a specified collocation window was determined. This number has been called the "cardinality of the collocating set" and is represented as |ℵ (w)|. It is proved that if |ℵ (w)| determined from this large document collection for any word w is fixed, then the maximum value of the CI for a word w is proportional to |ℵ (w)|. This constrained maximum is the "Discrimination Threshold" and is used as the base value of CI. Experimental evidence detailed in this thesis shows that sentences containing words with CI greater than DT are most likely to be useful in an extract. Words in every sentence of the document(s) being summarized have been assigned scores based on the difference between their current value of CI and their respective DT. Individual word scores have been summed to derive a score for every sentence. Sentences are ranked according to their scores and the first few sentences in the rank order have been selected as the extract summary. Redundant and semantically similar sentences have been excluded from the selection process using a simple similarity detection algorithm. This novel method for extraction has been called ESCI in this thesis. In the second part of the thesis, the advantages of tagging words as nouns, verbs, adjectives and adverbs without the use of sense disambiguation has been explored. A hierarchical model for abstraction of knowledge has been proposed, and those cases where such a model can improve summarization accuracy have been explained. Knowledge abstraction has been achieved by converting collocations into their hypernymous versions. In the second part of the thesis, the advantages of tagging words as nouns, verbs, adjectives and adverbs without the use of sense disambiguation has been explored. A hierarchical model for abstraction of knowledge has been proposed, and those cases where such a model can improve summarization accuracy have been explained. Knowledge abstraction has been achieved by converting collocations into their hypernymous versions. The number of levels of abstraction varies based on the sense tag given to each word in the collocation being abstracted. Once abstractions have been determined, Expectation- Maximization algorithm is used to determine the probability value of each collocation at every level of abstraction. A combination of abstracted collocations from various levels is then chosen and sentences are assigned scores based on collocation information of these abstractions.This summarization scheme has been referred to as De-ESCI (Dictionary enhanced ESCI). It had been observed in many human summary data sets that the factual attribute of the human determines the choice of noun and verb pairs. Similarly, the emotional attribute of the human determines the choice of the number of noun and adjective pairs. In order to bring these attributes into the machine generated summaries, two variants of DeESCI have been proposed. The summarizer with the factual attribute has been called as De-ESCI-F, while the summarizer with the emotional attribute has been called De-ESCI-E in this thesis. Both create summaries having two parts. First part of the summary created by De-ESCI-F is obtained by scoring and selecting only those sentences where a fixed number of nouns and verbs occur.The second part of De-ESCI-F is obtained by ranking and selecting those sentences which do not qualify for the selection process in the first part. Assigning sentence scores and selecting sentences for the second part of the summary is exactly like in ESCI. Similarly, the first part of De-ESCI-E is generated by scoring and selecting only those sentences where fixed number of nouns and adjectives occur. The second part of the summary produced by De-ESCI-E is exactly like the second part in De-ESCI-F. As the model summary generated by human summarizers may or may not contain sentences with preference given to qualifiers (adjectives), the automatic summarizer does not know apriori whether to choose sentences with qualifiers over those without qualifiers. As there are two versions of the summary produced by De-ESCI-F and De-ESCIE, one of them should be closer to the human summarizer’s point of view (in terms of giving importance to qualifiers). This technique of choosing the best candidate summary has been referred to as De-ESCI-F/E. Performance Metrics The focus of this thesis is to propose new models and sentence ranking techniques aimed at improving the accuracy of the extract in terms of sentences selected, rather than on the readability of the summary. As a result, the order of sentences in the summary is not given importance during evaluation. Automatic evaluation metrics have been used and the performance of the automatic summarizer has been evaluated in terms of precision, recall and f-scores obtained by comparing its output with model human generated extract summaries. A novel summary evaluator called DeFuSE has been proposed in this thesis, and its scores are used along with the scores given by a standard evaluator called ROUGE. DeFuSE evaluates an extract in terms of precision, recall and f-score relying on The use of WordNet hypernymy structure to identify semantically similar sentences in a document. It also uses fuzzy set theory to compute the extent to which a sentence from the machine generated extract belongs to the model summary. Performance of candidate summarizers has been discussed in terms of percentage improvement in fscore relative to the baselines. Average of ROUGE and DeFuSE f-score for every summary is computed, and the mean value of these scores is used to compare performance improvement. Performance For illustrative purposes, DUC 2002 and DUC 2003 multi-document data sets have been used. From these data sets only the 400 word summaries of DUC 2002 and track-4 (novelty track) summaries of DUC 2003 are useful for evaluation of sentence extracts and hence only these have been used. f-score has been chosen as a measure of performance. Standard baselines such as coverage, size and lead and also probabilistic baselines have been used to measure percentage improvement in f-score of candidate summarizers relative to these baselines. Further, summaries generated by MEAD using centroid and length as features for ranking (MEAD-CL), MEAD using positional, centroid and length as features for ranking (MEAD-CLP), Microsoft Word automatic summarizer (MS-Word) and Latent Semantic Indexing (LSI) based summarizer were used to compare the performance of the proposed summarization schemes.
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Seleção de leveduras para fermentação com alta pressão osmótica usando processo de fermentação extrativa / Yeast selection for high osmotic pressure fermentation by extractive fermentation process

Novello, Alexandra Pavan 09 February 2015 (has links)
Processos fermentativos que visam um salto tecnológico na produção de etanol, que potencialize o processo fermentativo, destaca-se a fermentação extrativa a vácuo. Assim buscou-se selecionar linhagens tolerantes à alta pressão osmótica para serem empregadas em processo de fermentação extrativa. Foram realizadas seleções a partir de 444 cepas de leveduras oriundas da biodiversidade das Usinas Brasileiras, que fazem parte do banco de leveduras do Centro de Tecnologia Canavieira (CTC), tendo como base o meio formulado com melaço e vinhaça para simular a fermentação extrativa. A seleção se baseou em submeter as linhagens às fermentações em condições crescentes de estresse osmótico, buscando destacar linhagens com a tolerância desejada. Para tal, as linhagens em mistura foram submetidas à propagação durante 93 gerações em meios com crescentes quantidades de melaço e vinhaça. Em etapa seguinte, 90 cepas foram isoladas e avaliadas mediante o crescimento (μmax e biomassa) em condição de estresse osmótico e genotipadas. O método usado na genotipagem foi o PCR - microssatélite, o qual permitiu verificar se as cepas resultantes da seleção eram cepas industriais (BG-1, CAT-1, PE-2 e SA-1) ou cepas selvagens e/ou predominantes. Foram utilizados 5 pares de primers representando 5 diferentes loci. A genotipagem e a avaliação do crescimento em condições de estresse osmótico, baseado em características genéticas e fisiológicas, permitiu identificar 24 linhagens com potencial de tolerância a pressão osmótica. As cepas com desempenho superior foram submetidas à avaliação de crescimento em placa e as sete mais tolerantes à pressão osmótica foram selecionadas e utilizadas em reciclos fermentativos empregando-se mosto constituído de melaço e vinhaça. A linhagem com as melhores características para a fermentação com alta pressão osmótica foi avaliada em condições de fermentação extrativa à vácuo. A linhagem selecionada, denominada de F1-5, mostrou-se com grande potencial para a fermentação extrativa quando comparada com a referência CAT-1. / Fermentative processes that aim for technology innovations in the ethanol production, which improve the fermentative process, emphasizing the in vacuum extractive fermentation. So we have selected strains tolerant for high osmotic pressure to be in extractive fermentation process for ethanol production. We 444 yeast strains from Brazilian Mills biodiversity, which Sugarcane Technology Center\'s (CTC) yeast bank, based on a medium formulated with molasses and vinasse, to simulate the extractive fermentation. The selection was based on submiting strains to the fermentation in in high osmotic stress condition, trying to feature strains with desired tolerance, so, the mixed strains were submitted to propagation for 93 generations in medium with increasing amounts of molasses and vinasse. In the following step, 90 strains were isolated and evaluated by growth (μmax and biomass) in osmotic stress condition and genotyped. The method used in genotyping was the PCR - microsatellite, which enable to estimate if resulting selection strains were from industrial strains (BG-1, CAT-1, PE-2 and SA-1) or wild strains and / or prevalent. 5 pairs of primers were used representing 5 different loci. The genotyping and the growth evaluation in osmotic stress conditions allowed identify strains based on genetic and physiological characteristics, making possible to identify 24 strains with a potential tolerance to osmotic pressure. The strains with better performance were submitted to evaluation growth on boards and the 7 most tolerant to osmotic pressure were selected and used in fermentative recycles using medium containing molasses and vinasse. The strain with the best features in the fermentation in high osmotic pressure was evaluated in vacuum extractive fermentation conditions. The selected strain, named F1-5, proved to have a great potential for extractive fermentation when compared to the reference CAT-1.
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Desenvolvimento de novos materiais para in-tube SPME acoplada on-line com UPLC-MS/MS e aplicações na análise de amostras de interesse ambiental e de alimentos. / Development of new materials for in-tube SPME coupled online with UPLC-MS/MS and applications in the analysis of environmental and food samples

Toffoli, Ana Lucia de 16 March 2018 (has links)
Frente a crescente necessidade de se monitorar diferentes contaminantes em matrizes complexas se faz necessário utilizar uma etapa de preparo de amostras eficiente e que esteja aliada à técnicas analíticas de elevada sensibilidade. Consequentemente, vem se aprimorando e desenvolvendo novos materiais sorventes utilizados para aumentar o desempenho do preparo de amostras e de fases estacionárias para cromatografia líquida de alta eficiência. Atualmente, materiais sorventes seletivos como líquidos iônicos, polímeros impressos molecularmente, grafeno, entre outros, vêm se destacando para extrair diferentes contaminantes. Diante desse contexto, esta tese teve como objetivo desenvolver diferentes materiais extratores para serem utilizados na microtécnica de extração in-tube SPME acoplada on-line com UPLC-MS/MS na análise de triazinas e sulfonamidas em matrizes complexas. O material que apresentou maior seletividade pelas classes dos compostos de interesse foi caracterizado por microscopia eletrônica de varredura e espectroscopia vibracional na região do infravermelho. Tanto para as triazinas quanto para as sulfonamidas o polímero impresso molecularmente apresentou maior afinidade e foi utilizado como fase extratora para extrair e pré-concentrar os analitos utilizando a microténica in-tube SPME UPLC-MS/MS. Além disso, para as triazinas utilizou-se também como fase de extração óxido de grafeno ancorado em sílica. As metodologias desenvolvidas nessa tese foram todas otimizadas e posteriormente validadas para analisar as matrizes de interesse que foram: uva, suco de uva integral, leite e água. Após à validação, as amostras foram analisadas com seus respectivos métodos validados, sendo que nenhum dos analitos foram encontrados considerando-se os limites das metodologias desenvolvidas, as quais se mostraram eficientes quando aplicadas nas análises das triazinas e sulfonamidas em suas respectivas amostras fortificadas. Outra abordagem explorada nesse trabalho foi o desenvolvimento de colunas tubulares abertas do tipo PLOT para serem utilizadas como colunas de extração em sistemas automatizados na cromatografia líquida. Colunas de sílica fundida foram preparadas para avaliar a formação da fase e sua aderência na parede do tubo. Para as colunas PS-DVB, os melhores resultados foram obtidos com duas horas de polimerização em banho de água. No entanto, para as colunas ODS a polimerização foi feita utilizando forno, e a fase não aderiu corretamente na parede do tubo para as colunas de 250 μm de diâmetro interno, requerendo estudos mais aprofundados para o preparo adequado destas colunas. / In view of the increasing need to monitor different contaminants in complex matrices, it is necessary to use efficient sample preparation techniques combined with highly sensitive analytical techniques. Consequently, new sorbent materials have been improved and developed to be used aiming to increase the performance of sample preparation and stationary phases for high performance liquid chromatography. Currently, selective sorbents such as ionic liquids, molecularly imprinted polymers, graphene, among others, have been emphasized to extract different contaminants. In this context, this thesis aimed to develop different extractive materials to be used in in-tube solid phase microextraction coupled on-line with UPLC-MS/MS in the analysis of triazines and sulfonamides in complex matrices. The material that presented greater selectivity for the classes of the compounds of interest was characterized by scanning electron microscopy and vibrational spectroscopy in the infrared region. For triazines and sulfonamides the molecularly imprinted polymer had higher affinity and was used as the extractive phase to extract and preconcentrate the analytes using the in-tube SPME UPLC-MS/MS. In addition, another extraction phase - graphene oxide anchored in silica - was also used. The methodologies developed in this thesis were all optimized and later validated to analyze the target compounds in the following matrices: grape, grape juice, milk and water. After the validation, the samples were analyzed with their respective validated methods and none of the analytes were found considering the limits of the methodologies developed, which were efficient when applied in the analysis of the triazines and sulfonamides in their respective fortified samples. Another approach explored in this work was the development of open tubular columns (PLOT) to be used as extraction columns in automated sample preparation - liquid chromatography systems. Silica columns were prepared in order to evaluate the formation of the phase and its adhesion to the tube wall. For the PS-DVB columns the best results were obtained with two hours of water-bath polymerization. However, for the ODS columns the polymerization done using an oven the phase did not adhere correctly in the tube wall the columns with 250 μm internal diameter. These results suggest that further experiments are required in order to better understand the preparation of these columns.
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A crítica da vida cotidiana da Reserva Extrativista Chico Mendes

Silva, Kárytha Krystyny Melo da January 2018 (has links)
Esta Dissertação de Mestrado Acadêmico tem como objetivo compreender como as contradições do Desenvolvimento Sustentável estão expressas na Reserva Extrativista Chico Mendes, localizada no Estado do Acre, Brasil, partindo da crítica da vida cotidiana na Reserva, através das premissas trazidas por Henri Lefebvre (2014). Para tanto, a análise da vida cotidiana na Reserva é desprendida da noção empírica, positivista e determinista da lógica formal que promovem um conhecimento fragmentado da realidade deixando escapar a essência dos fenômenos e das coisas, rejeitando a existência de contradições ou qualquer negação daquilo que é definido como absoluto e certo. Logo, analisar como as contradições do Desenvolvimento Sustentável estão expressas na Reserva Extrativista Chico Mendes é, ao mesmo tempo, compreender como a negação das situações cotidianas podem promover o movimento do pensar dentro daquela realidade, fazendo surgir novas possibilidades que influenciem novas escolhas, julgamentos e ações, e por isso refletem uma promessa de superação e transformação da realidade cotidiana. Em razão disso, o presente trabalho foi realizado a partir dos fatos diários, o que propiciou concluir que, justificadas pelo Desenvolvimento Sustentável, contradições históricas são perpetuadas prevalecendo a apropriação capitalista da natureza e a exploração do trabalhador. Os trabalhadores estão submetidos às práticas degradantes do capitalismo, e encontram-se envolvidos por aparências que encurralam seu potencial social, ao mesmo tempo que oferece-lhes o desconhecimento da sua verdadeira realidade social. / This Master's Dissertation aims to understand how the contradictions of Sustainable Development are expressed in the Chico Mendes Extractive Reserve, located in the State of Acre, Brazil. The research seeks to understand these contradictions starting from the critical study of the daily life of the Reserve, through the premises brought by Henri Lefebvre (2014). For this, the analysis of the daily life of the Reserve is detached from the empirical, positivist and deterministic notion of the formal logic that promotes a fragmented knowledge of reality leaving out the essence of phenomena and things, rejecting the existence of contradictions or any negation of what is defined as absolute and certain. Therefore, analyzing how the contradictions of Sustainable Development are expressed in the Extractive Reserve Chico Mendes is at the same time to understand how the denial of everyday situations can promote the movement of thinking within that reality, giving rise to new possibilities that influence new choices, judgments and actions and therefore reflect a promise of overcoming and transforming everyday reality. As a result, the present work was based on daily facts, which led to the conclusion that, justified by sustainable development, historical contradictions are perpetuated, prevailing capitalist appropriation of nature and exploration of the worker. Workers are subjected to the degrading practices of capitalism, and are surrounded by appearances that corral their social potential, while at the same time offering them the ignorance of their true social reality.

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