I detta arbete studerades landskapsförändringar, i synnerhet olika typer av gräsmarkshabitat i fråga om artinnehåll och rikedom samt hur dagens diversitetsmönster har påverkats av den historiska markanvändningen. Undersökningsområdet har en area av ca 143 ha och är beläget i nordöstra Skåne. Resultatet visade att områdets areal av naturliga gräsmarker var mest omfattande kring 1783/98 och minst 1926-23. De naturliga gräsmarkernas omfattning har nästan halverats från slutet av 1700-talet till idag. Andelen betesmark som har hävdats från 1700-talets slut till 2014 utgör dock inte mer än 11 % av betesmarkernas totala areal. Väg- och dikesren uppvisade störst andel arter som var gemensamma med naturbetesmarkernas; minst var andelen i kultiverad gräsmark. Artrikedomen var minst lika hög i vägren, dikesren och skogsbryn som i naturbetesmarken medan den var lägre i kuliverad gräsmark. Artrikedomen var högst på vägrenen.

關於描述兩個觀察地A和B相似的程度而言，生物品種是否相同是其中的一個切入點，因此品種重複（species overlap）便為描述兩觀察地相似度的一種指標。就一般的生物或生態研究而言，較常使用的品種重複指數為以品種數為計算基礎的 Jaccard index，公式為 ，其中 和 分別為觀察地A和B的總品種數，而 則為兩地的共同品種數，這樣的計算方式為Gower(1985) 歸類描述兩單位（unit）的相似度（similarity）中的一種。在我們的研究中，將令依觀察到的品種數及品種重複數所計算出的 Jaccard index 視為估計值，記為 ；若描述相似度時僅以品種為計算單位，而忽略個別品種的數量未免有資訊流失的情形，因此我們延伸 Jaccard index 指數而另立以個別品種數為計算單位的 N 指數，並以無母數最大概似估計法（Nonparametric Maximum Likelihood Estimator, NPMLE）估計 N 指數，記為 。另外，Smith, Solow 和 Preston (1996) 也提出利用 delta-beta-binomial 模型修正 Jaccard index 的低估（underestimate）情形，我們將此模型所推估的品種重複記為 ，因此我們的研究重點便在於以模擬實驗比較 、 和 在估計真正參數時的行為。 在模擬實驗中，根據蒙地卡羅（Monte-Carlo）模擬法則，我們設計6種品種發生機率相等的平衡母體，及12種品種發生機率服從幾何分配的不平衡母體，以500次抽樣所得的平均數及標準差決定估計的好壞。根據研究結果，若在已知母體為平衡母體的情形之下， 和 有不錯的估計；而 則是不管在平衡母體或不平衡母體皆有不錯的估計，但 和 在某些不平衡母體時，卻有極偏差的估計。 除了模擬實驗之外，我們並推導出 的期望值和變異數，並證明其為 N 指數的大樣本不偏估計值（asymptotic unbiased estimator），並以台灣西北部濕地的鳥類記錄為實例，計算出三個估計值，並以跋靴法（Bootstrapping）計算出三個估計量的標準差估計值，發現NPMLE 有最小的變異程度。 / In describing the similarity between communities A and B, species overlap is one kind of measure. In ecology and biology, the Jaccard index (Gower, 1985) ,denoted , for species overlap is widely used and is useded as an estimation in our research. However, the Jaccard index is simply the proportion of overlapping species, that is those species appearing in more than one community, to unique species, that is those species appearing in only one community. However, this index ignores species proportion information, assigning equal weight to all species. We propose a new index, N, which includes proportion information and is estimated by a Nonparametric Maximum Likelihood Estimator (NPMLE), denoted . Smith et al. (1996) proposed a delta-beta-binomial model to improve underestimation of the Jaccard index, we denoted this estimator . In our Monte-Carlo simulations, we design 6 balanced populations in which every species has an equal proportion and 12 unbalanced populations in which species proportions follow a geometric distribution. We found that and are accurate for balanced populations but overestimate or underestimate the true value for some unbalanced populations. However, is robust for both balanced and unbalanced populations. In addition to simulation results, we also give theoretical results, which prove some asymptotic properties of NPMLE .For example, species abundance of wild birds communications occurred at two locations in north-western Taiwan.Via bootstrapping, has smaller standard error than and .

Vulnerable code may cause security breaches in software systems resulting in financial and reputation losses for the organizations in addition to loss of their customers’ confidential data. Delivering proper software security training to software developers is key to prevent such breaches. Conventional training methods do not take the code written by the developers over time into account, which makes these training sessions less effective. We propose a method for recommending computer–security training to help identify focused and narrow areas in which developers need training. The proposed method leverages the power of static analysis techniques, by using the flagged vulnerabilities in the source code as basis, to suggest the most appropriate training topics to different software developers. Moreover, it utilizes public vulnerability repositories as its knowledgebase to suggest community accepted solutions to different security problems. Such mitigation strategies are platform independent, giving further strength to the utility of the system. This research discussed the proposed architecture of the recommender system, case studies to validate the system architecture, tailored algorithms to improve the performance of the system, and human subject evaluation conducted to determine the usefulness of the system. Our evaluation suggests that the proposed system successfully retrieves relevant training articles from the public vulnerability repository. The human subjects found these articles to be suitable for training. The human subjects also found the proposed recommender system as effective as a commercial tool.

Ένα e-portfolio είναι μία συλλογή περιεχομένου την οποία κατασκευάζει και διατηρεί ένας χρήστης στο Web. Το περιεχόμενο μπορεί να περιλαμβάνει κείμενο, αρχεία, εικόνες, multimedia, blogs κτλ. και μπορεί να χρησιμοποιηθεί για διάφορους σκοπούς. Σκοπός της εργασίας αυτής ήταν η δημιουργία πλατφόρμας παραγωγής eportfolios, με στόχο τη διαδικτυακή της χρήση. Η όλη πλατφόρμα δημιουργήθηκε με τη χρήση των γλωσσών προγραμματισμού HTML,PHP, Javascript, Ajax και τον εξυπηρετητή βάσεων δεδομένων Mysql. Ειδικότερα, υλοποιήθηκε μια πλατφόρμα παραγωγής προσωποποιημένων eportfolio με ιδιαίτερη βαρύτητα σε λειτουργίες κοινωνικής δικτύωσης. Στα eportfolios που δημιουργούνται, ο ιδιοκτήτης έχει τη δυνατότητα να ανεβάζει εικόνες, βίντεο και έγγραφα, να τα παρουσιάζει σε galleries, να τα οργανώνει σε κατηγορίες και να παρουσιάζει πληροφορίες αναφορικά με το άτομό του. Οι χρήστες, από την άλλη, μπορούν να επισκέπτονται τα eportfolios, να βλέπουν τα αρχεία που έχει ανεβάσει ο ιδιοκτήτης, να τα σχολιάζουν, να κάνουν share ή like με τη χρήση του facebook λογαριασμού τους ή tweet με τον ατίστοιχο λογαριασμό twitter. Με τον τρόπο αυτό επιτυγχάνεται μια θετική ανάδραση μεταξύ άυτών και του ιδιοκτήτη στοχεύοντας στην ανταλλαγή απόψεων, στη βελτίωση των ικανοτήτων του κατόχου, αλλά και του συστήματος γενικότερα. Στα πρωτοποριακά χαρακτηριστικά του συστήματος περιλαμβάνεται η δυνατότητα αναζήτησης στα δύο μεγαλύτερα κοινωνικά δίκτυα (Facebook και Twitter) για οτιδήποτε σχετικό με κάποιο από τα αρχεία που έχει ανεβάσει κάποιος χρήστης στο eportfolio του. Χρησιμοποιείται για το σκοπό αυτό το API του facebook. Επίσης, το σύστημα έχει τη δυνατότητα να προτείνει στους χρήστες του να επισκεφτούν eportfolios άλλων χρηστών με παρόμοια θεματολογία με τη χρήση tags και του Jaccard index. Τέλος, δίνεται η δυνατότητα στους χρήστες να ενημερώνονται για τις τελευταίες δραστηριότητες που υπάρχουν σε όλα τα eportfolios, μέσω της υπηρεσίας RSS, εόσον βέβαια κάνουν εγγραφή σε αυτή. ολο το σύστημα υλοποιήθηκε με βασικό γνώμονα την ευχρηστία και την καλύτερη εξυπηρέτηση των χρηστών. Η εφαρμογή μπορεί να χρησιμοποιηθέι άμεσα για προσωπική χρήση από κάθε ενδιαφερόμενο, αλλά και για διδακτικούς σκοπούς στην εξ αποστάσεως εκπαίδευση. / An electronic portfolio is a collection of electronic evidence assembled and managed by a user, usually on the Web. Such electronic evidence may include inputted text, electronic files, images, multimedia, blog entries and can be used for various purposes. The aim of this thesis was the creation of an Eportfolio Development Platform, which will be used on Web. The whole platform was developed by using the HTML, PHP, Ajax and Javascript Programming Languages and the Mysql Database Management System. Specifically, the eportfolios that will be created are personalized eportfolios with many social features. The owner can upload pictures, videos and documents, present them in galleries, organize them in categories and share information about himself and his career/work. Visitors, on the other hand, can view the uploaded files, comment, share or like via facebook or tweet via twitter. As a result, there can be a very positive feedback between the owner and the visitors. The desirable outcome will be the improvement of the owner’ s skills and abilities as well as the system’s features. The new features that the system provide, include searching on the two biggest online social networks (Facebook and Twitter) for anything that is relevant to the files that are presented in the system's eportfolios. This was implemented, using the Facebook Graph API. Also, the system can suggest its users to visit eportfolios whose topic is close to their own eportfolio's topic, using tags and Jaccard index. Finally, users can be informed of the recent activity in any eportfolio, through the RSS service, if they had been subscribed on it. The whole platform was implemented with the basic concern being the usability and the best servicing for the users. The system can be used easily either for personal reasons or for elearning.

Cette thèse est consacrée au problème de la comparaison de deux partitions non strictes (floues/probabilistes, possibilistes) d’un même ensemble d’individus en plusieurs clusters. Sa résolution repose sur la définition formelle de mesures de concordance reprenant les principes des mesures historiques développées pour la comparaison de partitions strictes et trouve son application dans des domaines variés tels que la biologie, le traitement d’images, la classification automatique. Selon qu’elles s’attachent à observer les relations entre les individus décrites par chacune des partitions ou à quantifier les similitudes entre les clusters qui composent ces partitions, nous distinguons deux grandes familles de mesures pour lesquelles la notion même d’accord entre partitions diffère, et proposons d’en caractériser les représentants selon un même ensemble de propriétés formelles et informelles. De ce point de vue, les mesures sont aussi qualifiées selon la nature des partitions comparées. Une étude des multiples constructions sur lesquelles reposent les mesures de la littérature vient compléter notre taxonomie. Nous proposons trois nouvelles mesures de comparaison non strictes tirant profit de l’état de l’art. La première est une extension d’une approche stricte tandis que les deux autres reposent sur des approches dite natives, l’une orientée individus, l’autre orientée clusters, spécifiquement conçues pour la comparaison de partitions non strictes. Nos propositions sont comparées à celles de la littérature selon un plan d’expérience choisi pour couvrir les divers aspects de la problématique. Les résultats présentés montrent l’intérêt des propositions pour le thème de recherche qu’est la comparaison de partitions. Enfin, nous ouvrons de nouvelles perspectives en proposant les prémisses d’un cadre qui unifie les principales mesures non strictes orientées individus. / This thesis is dedicated to the problem of comparing two soft (fuzzy/ probabilistic, possibilistic) partitions of a same set of individuals into several clusters. Its solution stands on the formal definition of concordance measures based on the principles of historical measures developped for comparing strict partitions and can be used invarious fields such as biology, image processing and clustering. Depending on whether they focus on the observation of the relations between the individuals described by each partition or on the quantization of the similarities between the clusters composing those partitions, we distinguish two main families for which the very notion of concordance between partitions differs, and we propose to characterize their representatives according to a same set of formal and informal properties. From that point of view, the measures are also qualified according to the nature of the compared partitions. A study of the multiple constructions on which the measures of the literature lie completes our taxonomy. We propose three new soft comparison measures taking benefits of the state of art. The first one is an extension of a strict approach, while the two others lie on native approaches, one individual-wise oriented, the other cluster-wise, both specifically defined to compare soft partitions. Our propositions are compared to the existing measures of the literature according to a set of experimentations chosen to cover the various issues of the problem. The given results clearly show how relevant our measures are. Finally we open new perspectives by proposing the premises of a new framework unifying most of the individual-wise oriented measures.

Protein sequences are essential for encoding molecular structures and functions. Consequently, biologists invest substantial resources and time discovering functional patterns in proteins. Using high-throughput technologies, biologists are generating an increasing amount of data. Thus, the major challenge in biosequencing today is the ability to conduct data analysis in an effi cient and productive manner. Conserved amino acids in proteins reveal important functional domains within protein families. Conversely, less conserved amino acid variations within these protein sequence patterns reveal areas of evolutionary and functional divergence. Exploring protein families using existing methods such as multiple sequence alignment is computationally expensive, thus pattern search is used. However, at present, combinatorial methods of pattern search generate a large set of solutions, and probabilistic methods require richer representations. They require biological ground truth of the input sequences, such as gene name or taxonomic species, as class labels based on traditional classi fication practice to train a model for predicting unknown sequences. However, these algorithms are inherently biased by mislabelling and may not be able to reveal class characteristics in a detailed and succinct manner. A novel pattern representation called an Aligned Pattern Cluster (AP Cluster) as developed in this dissertation is compact yet rich. It captures conservations and variations of amino acids and covers more sequences with lower entropy and greatly reduces the number of patterns. AP Clusters contain statistically signi cant patterns with variations; their importance has been confi rmed by the following biological evidences: 1) Most of the discovered AP Clusters correspond to binding segments while their aligned columns correspond to binding sites as verifi ed by pFam, PROSITE, and the three-dimensional structure. 2) By compacting strong correlated functional information together, AP Clusters are able to reveal class characteristics for taxonomical classes, gene classes and other functional classes, or incorrect class labelling. 3) Co-occurrence of AP Clusters on the same homologous protein sequences are spatially close in the protein's three-dimensional structure. These results demonstrate the power and usefulness of AP Clusters. They bring in similar statistically signifi cance patterns with variation together and align them to reveal protein regional functionality, class characteristics, binding and interacting sites for the study of protein-protein and protein-drug interactions, for diff erentiation of cancer tumour types, targeted gene therapy as well as for drug target discovery.