109 research outputs found

    AUTOREGRESSIVE SEQUENCES VIA LÉVY PROCESSES Author:

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    We use Lévy processes to develop a family of first-order autoregressive sequences of random variables with values in R+, called C-AR(1) processes. We obtain various distributional and regression properties for these processes and we establish a limit theorem that leads to the property of stationarity. A connection between stationarity of C-AR(1) processes and the notion of C-self-decomposability of van Harn and Steutel (1993) is discussed. A number of stationary C-AR(1) processes with specific marginals are presented and are shown to generalize several existing R+-valued AR(1) models. The question of time reversibility is addressed and some examples are discussed. Key-Words: stationarity; semigroup of cumulant generating functions; self-decomposability; stability; time-reversibility. AMS Subject Classification: • 60G10, 62M10. 82 Nadjib BouzarAutoregressive Sequences 8

    Fouille de données déclarative basée sur la programmation par contraintes.

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    La fouille de données est l'art de découvrir des informations à partir de bases de données.L'utilisateur spécifie le type de motifs à extraire et le spécialiste utilise des techniques pour trouver les motifs requis.De nombreuses techniques ont été introduites pour l'extraction des motifs classiques tels que les motifs fréquents, les règles d'association, etc.Cependant, l'extraction des motifs avec des propriétés supplémentaires restent un problème pour les spécialistes car des efforts algorithmiques sont requises pour gérer ces propriétés.Récemment, les chercheurs ont profité de la flexibilité de la programmation par contraintes pour modéliser plusieurs problèmes de la fouille de données.En termes de temps d'exécution, les méthodes basées sur la programmation par contraintes ne sont pas encore concurrentes avec les algorithmes spécialisées.Cependant, leur flexibilité permet la modélisation des requêtes complexes sans la nécessité de réviser le processus de résolution.Dans cette thèse, nous proposons d’utiliser la programmation par contraintes pour résoudre des problèmes de la fouille de données.Notre première contribution est un modèle basé sur la programmation par contraintes pour l'extraction des règles d'association.Pour mettre en œuvre notre modèle, nous introduisons une nouvelle contrainte globale,CONFIDENT, pour assurer la confiance des règles.Nous prouvons que propager complètement CONFIDENT est NP-difficile.Nous fournissons donc un propagateur non-complet et une décomposition pour la contrainte CONFIDENT.Nous capturons également les règles minimales non redondantes, une représentation condensée des règles d'association, en introduisant la contrainte globale GENERATOR. GENERATOR est utilisé pour extraire des motifs qui sont des générateurs. Pour cette contrainte, nous proposons un propagateur polynomial complet.Notre deuxième contribution est un model générique basé sur la programmation par contraintes permettant l'extraction des deux frontières des motifs fréquents, à savoir la frontière positive ou les motifs maximaux fréquents et la frontière négative ou les motifs minimaux infréquents.Il est facile de choisir la frontière à extraire en fixant un simple paramètre.Pour cela, nous introduisons deux nouvelles contraintes globales, FREQUENTSUBS et INFREQUENTSUPERS,avec des propagateurs polynomiaux complets.Nous examinons ensuite le problème de l'extraction des frontières avec des contraintes supplémentaires.Nous prouvons que ce problème est coNP-difficile. Cela implique qu’il n’existe aucun CSP représentant ce problème (sauf si coNP est dans NP).Data mining is the art of discovering knowledge from databases. The user specifies the type of patterns to be mined, and the miner uses techniques to find the required patterns. Many techniques have been introduced for mining traditional patterns like frequent itemsets, association rules, etc. However, mining patterns with additional properties remains a bottleneck for specialists nowadays due to the algorithmic effort needed to handle these properties.Recently, researchers have taken advantage of the flexibility of constraint programming to model various data mining problems. In terms of CPU time, constraint programming-based methods have not yet competed with ad hoc algorithms. However, their flexibility allows the modeling of complex user queries without revising the solving process.In this thesis we propose to use constraint programming for modeling and solving some well known data mining problems.Our first contribution is a constraint programming model for mining association rules. To implement our model, we introduce a new global constraint, CONFIDENT, for ensuring the confidence of rules.We prove that completely propagating CONFIDENT is NP-hard. We thus provide a non-complete propagator and a decomposition for CONFIDENT. We also capture the minimal non-redundant rules, a condensed representation of association rules, by introducing the global constraint GENERATOR. GENERATOR is used for mining itemsets that are generators. For this constraint, we propose a complete polynomial propagator.Our second contribution is a generic framework based on constraint programming to mine both borders of frequent itemsets, i.e. the positive border or maximal frequent itemsets and the negative border or minimal infrequent itemsets. One can easily decide which border to mine by setting a simple parameter. For this, we introduce two new global constraints, FREQUENTSUBS and INFREQUENTSUPERS, with complete polynomial propagators. We then consider the problem of mining borders with additional constraints. We prove that this problem is coNP-hard, ruling out the hope for the existence of a single CSP solving this problem (unless coNP is in NP)

    Parallel Constraint Acquisition

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    Constraint acquisition systems assist the non-expert user in modelling her problem as a constraint network. QUACQ is a sequential constraint acquisition algorithm that generates queries as (partial) examples to be classified as positive or negative. The drawbacks are that the user may need to answer a great number of such examples, within a significant waiting time between two examples, to learn all the constraints. In this paper, we propose PACQ, a portfolio-based parallel constraint acquisition system. The design of PACQ benefits from having several users sharing the same target problem. Moreover, each user is involved in a particular acquisition session, opened in parallel to improve the overall performance of the whole system.We prove the correctness of PACQ and we give an experimental evaluation that shows that our approach improves on QUACQ

    Analyse de code en boîte noire pour la rétro ingénierie via acquisition de contraintes et synthèse de code

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    Les logiciels sont de plus en plus grands et complexes. Ainsi, certaines tâches comme le test et la vérification de code, ou la compréhension de code, sont de plus en plus difficiles à réaliser pour un humain. D'où la nécessité de développer des méthodes d'analyse automatique. Celles-ci sont usuellement en boîte blanche, utilisant la syntaxe du code pour déduire ses propriétés. Elles sont très efficaces mais présentent certaines limitations: le code source est nécessaire, la taille et la complexité syntaxique du code (accentuée par des optimisations et de l'obfuscation) impactent leur efficacité. Cette thèse explore comment les méthodes en boîte noire peuvent inférer des propriétés utiles pour la rétro-ingénierie. Nous étudions, tout d'abord, l'inférence de contrat de fonction qui tente d'apprendre sur quelles entrées une fonction peut être exécutée pour obtenir les sorties souhaitées. Nous adaptons l'acquisition de contraintes, en résolvant une de ses principales limitations: la dépendance à un être humain. En ressort PreCA, la première approche totalement boîte noire offrant des garanties claires de correction. PreCA est ainsi particulièrement approprié pour l'aide au développement. Nous étudions ensuite la déobfuscation, qui vise à simplifier du code obfusqué. Nous proposons Xyntia qui synthétise, via des S-métaheuristiques, une version compréhensible de blocs de code. Xyntia est plus rapide et robuste que l'état de l'art. De plus, nous proposons les deux premières protections contre la déobfuscation en boîte noire.Software always becomes larger and more complex, making crucial tasks like code testing, verification, or code understanding highly difficult for humans. Hence the need for methods to reason about code automatically. These are usually white-box, and use the code syntax to deduce its properties. While they have proven very powerful, they also show limitations: they need the source code, the code size and the data structures' complexity degrade their efficiency, they are highly impacted by syntactic code complexity amplified by optimizations obfuscations. This thesis explores how black-box code analysis can infer valuable properties for reverse engineering through data-driven learning. First, we consider the function contracts inference problem, which aims to infer over which inputs a code function can be executed to get good behaviors only. We extend the constraint acquisition learning framework, notably solving one of its major flaws: the dependency on a human user. It leads to PreCA, the first black-box approach enjoying clear theoretical guarantees. It makes PreCA especially suitable for development uses. Second, we consider the deobfuscation problem, which aims to simplify obfuscated code. Our proposal, Xyntia, synthesizes code block semantics through S-metaheuristics to offer an understandable version of the code. Xyntia significantly improves the state-of-the-art in terms of robustness and speed. In addition, we propose the two first protections efficient against black-box deobfuscation

    The Value of Islamic Education in The Book of Anggukan Ritmis Kaki Pak Kiai by Emha Ainun Nadjib

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    This study is trying to describe the results of the analysis of Islamic Educational Values in the book of Anggukan Ritmis Kaki Pak Kiai by Emha Ainun Nadjib or commonly called Cak Nun and at the same time looking at the reconstruction of the concept or values of education offered with the needs and challenges of today's education. This study uses a library research approach with direct data sources from the book of Anggukan Ritmis Kaki Pak Kiai and Emha's books relevant to this research based on the analytical methods and content analysis. The results of this study or the Islamic Educational Values that the author found in the book of Anggukan Ritmis Kaki Pak Kiai talk about the peak of one's faith is monotheism, the net is through piety, and its manifestation is Rahmatan Lil 'Alamin. Then, the value of moral education is to question our attitude toward non-Muslims, re-understanding the meaning of Ukhuwah Islamiyah broadly and deeply. What is contained in the value of Islamic Education includes worship as a Manifestation of Love for Allah by understanding the concept of reward more broadly, Prayer, Fasting, Zakat, and Hajj. Meanwhile, the meaning of an educator, according to "Emha Ainun Nadjib in the book of Anggukan Ritmis Kaki Pak Kiai, is someone who can not only educate but can also position himself as a student anytime, anywhere, and to anyone

    MODERASI BERAGAMA PERSPEKTIF EMHA AINUN NADJIB DALAM MEWUJUDKAN TOLERANSI BERAGAMA DAN RELEVANSINYA TERHADAP PENDIDIKAN AGAMA ISLAM

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    ABSTRAK Indonesia adalah termasuk negara yang penduduknya majemuk dalam suku, adat, budaya dan agama. Kemajemukan dalam hal agama terjadi karena masuknya agama�agama besar ke Indonesia. Tentu dalam menjaga keberagaman dan kemajemukan tidak mudah seperti membalikkan tangan. Sering sekali terjadi konflik antar internal umat agama maupun antar umat beragama. Sesungguhnya moderasi beragama atau Islam wasathiyyah merupakan kunci terciptanya toleransi dan kerukunan, baik di tingkat lokal, nasional, maupun global. Penelitian ini bertujuan untuk menganalisis konsep moderasi beragama dan Relevansi Konsep moderasi beragama dalam perspektif Emha Ainun Nadjib terhadap Pendidikan Agama Islam. Penelitian ini menggunakan pendekatan kualitatif dengan jenis penelitian studi kepustakaan. Pengumpulan data menggunakan metode dokumentasi dengan menelusuri sumber data primer dan sekunder. Teknis analisis data meliputi analisis isi, deskripsi, komparasi, interpretasi dan penarikan kesimpulan. Hasil dari penelitian ini menunjukkan pemikiran Emha Ainun Nadjib tentang moderasi beragama serta relevansinya terhadap Pendidikan Agama Islam mengarah pada sikap menjunjung tinggi toleransi dan keadilan sesama umat beragama serta tidak merasa benar sendiri dan tidak menyalahkan orang lain. Moderasi beragama sejatinya lampu yang menyinari seorang hamba untuk berjalan melakukan ajaran Islam dengan baik dan toleran. Hal yang perlu ditekankan oleh penulis di sini dalam penerapan moderasi beragama adalah Pertama, tidak bersikap ekstrem dalam menyebarkan ajaran agama. Kedua, tidak mudah mensalahkan atau mengkafirkan sesama Muslim, karena beda pemahaman agama. Ketiga, memposisikan diri dalam kehidupan di tengah masyarakat dengan senantiasa memegang teguh prinsip persaudaraan (ukhuwah) dan toleransi (tasamuh) antar sesama umat beragama dan sesama warga negara. Adapun relevansi pemikiran Emha Ainun Nadjib dalam Pendidikan Agama Islam meliputi peran orang tua, guru, lembaga pendidikan dan masyarakat sekitar untuk ikut serta ambil bagian dalam membentuk karakter serta pemahaman peserta didik dalam menerapkan moderasi beragama dan Pemikiran Emha Ainun Nadjib terhadap Pendidikan Agama Islam yang meliputi media, materi, dan evaluasi karena dengan metode ini peserta didik akan mengerti keilmuan Islam secara menyeluruh dan dengan semua ilmu itu menjadikan generasi Islam yang semakin dekat dengan Allah, manusia dan semua makhluk hidup. Bukan itu saja, peserta didik juga akan semakin paham arti hidup yang sebenarnya, sehingga kehidupan seorang muslim akan semakin membaik hari demi hari dengan adanya Islam dan pendidikannya. Kata Kunci : Moderasi Beragama, Emha Ainun Nadjib, Pendidikan Agama Islam iii ABSTRACT Indonesia is a country whose population is diverse in terms of ethnicity, customs, culture and religion. Diversity in terms of religion occurs because of the entry of major religions into Indonesia. Of course, maintaining diversity and pluralism is not as easy as turning hands. There are often conflicts between internal and inter-religious people. In fact, religious moderation or wasathiyyah Islam is the key to creating tolerance and harmony, both at the local, national and global levels. This study aims to analyze the concept of religious moderation and the relevance of the concept of religious moderation in Emha Ainun Nadjib's perspective on Islamic Religious Education. This research uses a qualitative approach with the type of literature study research. Data collection uses the documentation method by tracing primary and secondary data sources. Technical data analysis includes content analysis, description, comparison, interpretation and drawing conclusions. The results of this study indicate that Emha Ainun Nadjib's thoughts on religious moderation and its relevance to Islamic Religious Education lead to an attitude of upholding tolerance and justice among religious people and not feeling self-righteous and not blaming others. Religious moderation is actually a lamp that illuminates a servant to walk in carrying out the teachings of Islam well and tolerantly. What the author needs to emphasize here in implementing religious moderation is first, not being extreme in spreading religious teachings. Second, it is not easy to blame or disbelieve fellow Muslims, because of different religious understandings. Third, positioning oneself in life in society by always upholding the principles of brotherhood (ukhuwah) and tolerance (tasamuh) among fellow religious people and fellow citizens. The relevance of Emha Ainun Nadjib's thoughts in Islamic Religious Education includes the role of parents, teachers, educational institutions and the surrounding community to take part in shaping the character and understanding of students in applying religious moderation and Emha Ainun Nadjib's thoughts on Islamic Religious Education which includes media , material, and evaluation because with this method students will understand Islamic scholarship thoroughly and with all that knowledge makes the Islamic generation closer to Allah, humans and all living things. Not only that, students will also understand the true meaning of life, so that the life of a Muslim will improve day by day with the existence of Islam and its education. Keywords : Religious Moderation, Emha Ainun Nadjib, Islamic Religious Educatio

    Discovering Program Topoi via Hierarchical Agglomerative Clustering

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    International audienceIn long lifespan software systems, specification documents can be outdated or even missing. Developing new software releases or checking whether some user requirements are still valid becomes challenging in this context. This challenge can be addressed by extracting high-level observable capabilities of a system by mining its source code and the available source-level documentation. This paper presents feature extraction and traceabil-ity (FEAT), an approach that automatically extracts topoi, which are summaries of the main capabilities of a program, given under the form of collections of code functions along with an index. FEAT acts in two steps: first, clustering: by mining the available source code, possibly augmented with code-level comments, hierarchical agglomerative clustering groups similar code functions. In addition, this process gathers an index for each function. Second, entry point selection: functions within a cluster are then ranked and presented to validation engineers as topoi candidates. We implemented FEAT on top of a general-purpose test management and optimization platform and performed an experimental study over 15 open-source software projects amounting to more than 1 M lines of codes proving that automatically discovering topoi is feasible and meaningful on realistic projects

    On Testing Constraint Programs

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    International audienceThe success of several constraint-based modeling languages such as OPL, ZINC, or COMET, appeals for better software engineer- ing practices, particularly in the testing phase. This paper introduces a testing framework enabling automated test case generation for constraint programming.We propose a general framework of constraint program de- velopment which supposes that a rst declarative and simple constraint model is available from the problem speci cations analysis. Then, this model is re ned using classical techniques such as constraint reformu- lation, surrogate and global constraint addition, or symmetry-breaking to form an improved constraint model that must be thoroughly tested before being used to address real-sized problems. We think that most of the faults are introduced in this re nement step and propose a pro- cess which takes the rst declarative model as an oracle for detecting non-conformities. We derive practical test purposes from this process to generate automatically test data that exhibit non-conformities. We im- plemented this approach in a new tool called CPTEST that was used to automatically detect non-conformities on two classical benchmark pro- grams, namely the Golomb rulers and the car-sequencing problem
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