Search

Smart Factories are designed by Universities [e.g. 7, 1] and Research Institutes (e.g. IPA, IFF, IOSB, IFF, DFKI). Also, automotive companies are developing their ‘own’ Smart Factories [e.g. 3, 6]. The focus is on manufacturing processes, technical equipment, and control of technical processes but not on business and order processes [4, 5]. To run a Smart Factory also a concept for a “Digital Order Twin” (DOT) is needed to ensure that for each final product the right components are available in the right quantity at the right time and at the right place, especially if the product is configurated by a customer or dealer. But existing IT-Systems for Enterprise-Resource-Planning (ERPS), Material-Requirement-Planning (MRP) and Manufacturing Execution (MES) are not able to exploit the huge amount of acquired data ‘in-time’, because they are separated IT-Modules which are connected by batch-oriented interfaces only, the concept and algorithm base on the “Water-Fall-Model” without recursion to a preceding IT-System or IT-Module. In an autonomously controlled Smart Factory the right components must be referenced to each single final product instantly and in a more flexible way than the concept of pearl chain can do, instead of a unique DOT uses instantly data of RFID, QR-Code, Smart Devices and Cyber-Physical Objects and can interact in time with Systems and Modules.

In this paper, I examine Williamson’s [15] counterfactual-based account of modal epistemology. I argue that such an account faces two serious problems—the cotenability problem and the gap problem. As I diagnose it, these problems somehow indicate that our standard way of understanding counterfactuals under the received possible-worlds semantics may have insufficient ‘structures’ to distinguish various different kinds of constraints on our counterfactual thinking. The remedy, I suggest, is to invoke the ‘structural semantics’ as developed by Pearl [10] and Halpern [4]. Based on this semantics, I offer some philosophical elucidation for various kinds of modality, and thereby provide a more satisfactory account of how our modal knowledge can be grounded in our knowledge of counterfactuals.

For several years, security experts and government officials have been warning about a “Cyber Pearl Harbor” – a cyber attack on the nation’s power grid. Current cyber security research focuses on the tactical aspects of infrastructure attacks and views attackers as passive agents, downplaying their strategies. The research only minimally incorporates the human element, which limits the understanding of cyber attacks on the critical infrastructure.

This research constructs the south sea pearl industry management information service platform based on the Internet of Things, analyzing the features and technical advantages of Internet of Things, as well as the current existing problems of the pearl Industrial management. We have investigated the application management model of the Internet of Things in the product flow of pearl industry from production to processing management and explored the application of the key technologies, like radio frequency identification (RFID), wireless sensor network (WSN), physical markup language (PML) and the Electronic Product Code (EPC), to the Internet of Things in the pearl industrial management information services application platform. With the hope to bridge and eliminate the gap caused by differences in technology and standards among various sectors in the South Sea pearl production, processing, marketing and distribution, thus integration and optimization of pearl industrial management will be promoted and developed healthily.

Similarity-based queries play an important role in many large scale applications. In bioinformatics, DNA sequencing produces huge collections of strings, that need to be compared and merged. We present PeARL, a data structure and algorithms for similarity-based queries on many-core servers. PeARL indexes large string collections in compressed tries which are entirely held in main memory. Parallelization of searches and joins is performed using MapReduce as the underlying execution paradigm. We show that our data structure is capable of performing many real-world applications in sequence comparisons in main memory. Our evaluation reveals that PeARL reaches a significant performance gain compared to single-threaded solutions. However, the evaluation also shows that scalability should be further improved, e.g., by reducing sequential parts of the algorithms.

We present a Prolog implementation of real-time persistent queues and double-ended queues. Our implementation is inspired by Okasaki's lazy-functional approach, but relies only on standard Prolog, comprising of the pure subset plus if-then-else constructs to efficiently implement guards and meta-calls for convenience. The resulting data structure is a nice demonstration of the fact that the use of logic variables to hold the outcome of an unfinished computation can sometimes give the same kind of elegant and compact solutions as lazy evaluation.

We describe two formal proofs of the finite version of Hall's Marriage Theorem performed with the proof assistant Isabelle/HOL, one by Halmos and Vaughan and one by Rado. The distinctive feature of our formalisation is that instead of sequences (often found in statements of this theorem) we employ indexed families, thus avoiding tedious reindexing of sequences.

This paper integrates Pearl's seminal work on probability and causality with that of Shafer. Using the language of CP-logic, it transposes Pearl's analysis of interventions and counterfactuals to the semantic context of Shafer's probability trees. This gives us definitions that work not on the level of random variables, but on the level of Humean events. There are some tangible benefits to our approach: we can elegantly handle counterfactuals in the context of cyclic causal relations, and are able to consider interventions that are both more fine-grained and more elaborate than Pearl's. Acceptance rate: 33% ispartof: pages:313-325 ispartof: Lecture Notes in Computer Science vol:6341 pages:313-325 ispartof: European Conference on Logics in Artificial Intelligence (JELIA) location:Helsinki, Finland date:13 Sep - 15 Sep 2010 status: published

A succinct SAT solver is presented that exploits the control provided by delay declarations to implement watched literals and unit propagation. Despite its brevity the solver is surprisingly powerful and its elegant use of Prolog constructs is presented as a programming pearl.

This pearl examines how to verify functional programs written using the state monad. It uses Coq's Program framework to provide strong specifications for the standard operations that the state monad supports, such as return and bind. By exploiting the monadic structure of such programs during the verification process, it becomes easier to prove that they satisfy their specification.

We introduce local soft belief updating, a new heuristic for taking into account relations that exist between entities in a database. Our idea applies Pearl's belief updating, but only in the first-order neighborhood of each node, thus avoiding any problems with loops. We apply our method to a classification problem using a subset of the Cora database of computer science articles, with Cora's citation graph giving the relations between entities.

The Mini-Rubik is the 2x2x2 version of the famous Rubik's cube. How many moves are required to solve the 3x3x3 cube is still unknown. The Mini-Rubik, being simpler, is always solvable in a maximum of 11 moves. This is the result that is formalised in this paper. From this formalisation, a solver is also derived inside the Coq prover. This rather simple example illustrates how safe computation can be used to do state exploration in order to derive non-trivial properties inside a prover.

Automatic trace analysis is an effective method of identifying complex performance phenomena in parallel applications. To simplify the development of complex trace-analysis algorithms, the earl library interface offers high-level access to individual events contained in a global trace file. However, as the size of parallel systems grows further and the number of processors used by individual applications is continuously raised, the traditional approach of analyzing a single global trace file becomes increasingly constrained by the large number of events. To enable scalable trace analysis, we present a new design of the aforementioned earl interface that accesses multiple local trace files in parallel while offering means to conveniently exchange events between processes. This article describes the modified view of the trace data as well as related programming abstractions provided by the new pearl library interface and discusses its application in performance analysis.

We reexamine the While combinator of higher-order logic (HOL) and introduce the For combinator. We argue that both combinators should be part of the toolbox of any HOL practitioner, not only because they make efficient computations within HOL possible, but also because they facilitate elegant inductive reasoning about loops. We present two examples that support this argument.

TERMINATOR is a static analysis tool developed by Microsoft Research for proving termination of Windows device drivers written in C. This proof pearl describes a formalization in higher order logic of the program analysis employed by Terminator, and verifies that if the analysis succeeds then program termination logically follows.

Causal nets (Pearl 1986) are an elegant way of representing the structure and relationships of a set of data. The propagation of changes through the net has been examined and reported on in many works (Pearl 1986, Lauritzen & Speigelhalter 1988, Neapolitan 1990). Causal nets are defined by the properties of conditional independence, and so the structure of the net may be obtained by discovering conditional independences. Many of the examples in the literature test for complete equality. However, the presence of noise and the unreliability of comparing two real numbers means that equality is taken to mean equality within a particular tolerance. Where a set of data contains a number of representative subsets this tolerance can be almost zero. If there is an incomplete subset in the data and conjoint events then the tolerance cannot be zero. The paper presents a method for estimating the size of the partial cohort, the size of the representative cohorts and thus provides a robust test for conditional independence.

Causality and belief changes play an important role in many applications. Recently, Pearl [6] has proposed approaches based on probability theory using causal graphs to give formal semantics to the notion of interventions. From representational point of view, interventions are distinguished from observations using the concept of the "do" operator [4]. From reasoning point of view, handling interventions consists in "ignoring" the effects of all direct (and undirected) causes related to the variable of interest.

We discuss a proof of the wellfounded induction theorem for the ordinals up to Ɛ0. The proof is performed on the embedding of ACL2 in HOL-4, thus providing logical justification for that embedding and supporting the claim that the ACL2 logic has a model.

In current constraint-based (Pearl-style) systems for discovering Bayesian networks, inputs with deterministic relations are prohibited. This restricts the applicability of these systems. In this paper, we formalize a sufficient condition under which Bayesian networks can be recovered even with deterministic relations. The sufficient condition leads to an improvement to Pearl's IC algorithm; other constraint-based algorithms can be similarly improved. The new algorithm, assuming the sufficient condition proposed, is able to recover Bayesian networks with deterministic relations, and moreover suffers no loss of performance when applied to nondeterministic Bayesian networks.

A way to specify component-based software architectures for embedded real-time systems is introduced. Component models are specified taking the Model Driven Architecture (MDA) approach, and employing UML notations. First, the principle of the developing process based on the MDA approach and the new concepts of UML-specified component architectures are addressed. Then, a conceptual framework architecture for the design of embedded real-time systems is presented, in which platform-independent component models are built. Taking specific platform features into regard, specific component models result from transformations mapping the platform-independent component model to either the Process and Experiment Automation Real-Time Language (PEARL) or to Function Blocks according to IEC 61131-3 or IEC 61499.

There are some problems in which the time required for evaluating a Bayesian network must not be long. This means that not all the propagation algorithms could be applied in these situations, and therefore an appropriate method must be chosen. A type of evaluation that fulfills this requirement is known generically as “anytime algorithm”. They are able to return an approximate output at any moment, solution that could be enough for some problems. In this paper two methods framed in this approach are presented. These are modifications of the Pearl’s exact propagation algorithm for singly connected networks, designed with the final aim of reducing the propagation effort in domain problems where the number of variables is very large and the domain knowledge could be represented using that topology. As a very suitable test bed for measuring their quality, the field of Information Retrieval was selected. Results of a detailed experimentation are presented as well, showing a good performance.

We provide a proof that the elegant trick of Olivier Danvy for expressing printf-like functions without dependent types is correct, where formats are encoded by functional expressions in continuation-passing style. Our proof is formalized in the Calculus of Inductive Constructions. We stress a methodological point: when one proves equalities between functions, a common temptation is to introduce a comprehension axiom and then to prove that the considered functions are extensionally equal. Rather than weakening the result (and adding an axiom), we prefer to strenghten the inductive argumentation in order to stick to the intensional equality.

In his book “The Art of Computer Programming”, Donald Knuth gives an algorithm to compute the first n prime numbers. Surprisingly, proving the correctness of this simple algorithm from basic principles is far from being obvious and requires a wide range of verification techniques. In this paper, we explain how the verification has been mechanised in the Coq proof system.

The parallel functional programming language Eden was specially designed to be implemented in a distributed setting. In a previous paper [3] we presented an operational specification of DREAM, the distributed abstract machine for Eden. In this paper we go a step further and present the imperative code generated for Eden expressions and how this code interacts with the distributed RunTime System (RTS) for Eden. This translation is done in two steps: first Eden is translated into PEARL (Parallel Eden Abstract Reduction Language), the parallel functional language of DREAM, and then PEARL expressions are translated into imperative code.

We propose a formal generalization for various works dealing with Heuristic Search in state graphs. This generalization focuses on the properties of the evaluation functions, on the characteristics of the state graphs, on the notion of path length, on the procedures that control the choices of the node expansions, on the rules that govern the updating operations. Consequently, we present new theorems about the subadmissibility. These theorems widely extend the analogous results previously published concerning Nilsson's A* algorithms and diverse successors due to Pohl (HPA), Harris (particular A), Martelli (B), Pearl and Kim (A*e), Ghallab and Allard (Ae), Bagchi and Mahanti (C), Pearl (BF*), Mero (B′), Korf (IDA*), Mahanti and Ray (D), Dechter and Pearl (A**). They provide a theoretical support for using diverse kinds of Heuristic Search algorithms in enlarged contexts.

The tendency to design the system-software of modern Programmable Logic Controllers (PLCs) on the basis of the features of well known realtime operating systems has influenced the IEC 1131 Standard for PLCs with respect to the inclusion of an explicit task model. This is a signiflcant step towards the inclusion of fault-tolerance, e.g. tolerating the missing of task-deadlines. The constructs for exception-handling and reconsguration of modern realtime-languages, e.g. PEARL 90, are well suited for a transparent and dependable implementation of fault-tolerance mechanisms in PLCs.

The discovery of causal relationships from empirical data is an important problem in machine learning. In this paper the attention is focused on the inference of probabilistic causal relationships, for which two different approaches, namely Glymour et al.'s approach based on constraints on correlations and Pearl and Verma's approach based on conditional independencies, have been proposed. These methods differ both in the kind of constraints they consider while selecting a causal model and in the way they search the model which better fits to the sample data. Preliminary experiments show that they are complementary in several aspects. Moreover, the method of conditional independence can be easily extended to the case in which variables have a nominal or ordinal domain. In this case, symbolic learning algorithms can be exploited in order to derive the causal law from the causal model.

The RDC-System (Really Distributed Computer Control System) developed by IITB has been successfully applied in many industrial automation projects. It provides distributed fault-tolerance and is based on a redundant fibre optical network. The application programs are highly real-time sensitive and are written in PEARL with extensions for distribution and fault-tolerance support. This paper gives a short outline of the main characteristics of RDC with respect to real-time, fault-tolerance and distribution and summarizes some lessons learnt from the multiple industrial applications in steel production and car manufacturing.

In this paper we describe an ESPRIT project known as ‘Stat-Log’ whose purpose is the comparison of learning algorithms. We give a brief summary of some of the algorithms in the project: linear and quadratic discriminant analysis, k nearest neighbour, CART, backpropagation, SMART, ALLOC80 and Pearl's polytree algorithm. We discuss the results obtained for two datasets, one of handwritten digits and the other of vehicle silhouettes.

The applicability of Knowledge Space Theory (Falmagne and Doignon) and Bayesian Belief Networks (Pearl) as probabilistic student models imbedded in an Intelligent Tutoring System is examined. Student modeling issues such as knowledge representation, adaptive assessment, curriculum advancement, and student feedback are addressed. Several factors contribute to uncertainty in student modeling such as careless errors and lucky guesses, learning and forgetting, and unanticipated student response patterns. However, a probabilistic student model can represent uncertainty regarding the estimate of the student's knowledge and can be tested using empirical student data and established statistical techniques.

In this paper the main results of DRUMS R.P3.3 Task ’Propagation of Uncertainty in Dependence Graphs’ are presented. It is divided in two parts. In the first one, it is considered a new calculus with imprecise probabilities, which is not as uninformative as classical one, [6, 7, 9]. In the second one, the axiomatic squeme given in [11] has been adapted to Pearl's causal networks, [10], by introducing three new axioms. Then, this axiomatic framework is particularized to the new calculus of upper and lower probabilities. It is shown that upper and lower probabilities may be propagated on causal networks on an analogous way to probabilities.

PEARL is a widely-used, standardised, industrial process-control programming language. The programs, that are written in PEARL, are typically expected to operate in a predictable, timely, reliable manner. Developing such programs is no easy task. Yet, with the invent of the experimental programming language Real-Time Euclid and its schedulability analyser, a tool that is used to predict whether real-time software will adhere to its critical timing constraints, it has been demonstrated that this task may be made considerably easier.

PEARL is a widely-used, standardised, industrial process-control programming language. The programs, that are written in PEARL, are typically expected to operate in a predictable, timely, reliable manner. Developing such programs is no easy task. Yet, with the invent of the experimental programming language Real-Time Euclid and its schedulability analyser, a tool that is used to predict whether real-time software will adhere to its critical timing constraints, it has been demonstrated that this task may be made considerably easier.

This essay gives the reasons why a high level programming language ist to be preferred for the use in process computer systems. After pointing out the requirements to be imposed on such a computer language system, those projects are listed branch-oriented, which were carried out by BBC using the PEARL-Subset PAS 2, implemented on the PDP 11 process computer family. The experience gained by the users as well as the conclusion that PEARL has stood the test, are described.

The semantics of the process control language PEARL has been described in a semi-formal way for the German Standard DIN 66 253 Part 2. The techniques used there, especially the connectors between sets of nodes in nets, are outlined here.

The control of a complex industrial robot today requires digital computers in a multicomputer arrangement, specially when the algorithms for decoupling the degrees of freedom, for the coordinate-transformation and for supervision and security are concerned. Programming such a multicomputer system by use of a higher level realtime language will reduce costs and increase the transparency and maintainability of the software system. After a discussion of the necessary language elements and a suited language structure the design of an appropriated language is shown. The design is implemented on the basis of the language PEARL (Process and Experiment Automation Realtime Language), extended by language divisions and elements for the description of the structure of hardware and software in multicomputer systems. A Dynamic Loader, carrying out the software configuration and reconfiguration in case of failures is explained.

In this paper a method for teaching, recording and on-line computing of continuous cutting trajectories for a computer controlled industrial robot (IR) used as cutting machine tool is presented. Like the algorithms for digital closed-loop control and coordinate transformation, the algorithm of cutting trajectory calculation has been formulated in the real-time programming language PEARL and implemented on a microcomputer. The proposed concept differs from the other well known methods used for conventional CNC-controlled machine tools in several points. It requires comparably low processing speed and memory capacity. Both the teaching of the measured points on the pattern workpiece and the interpolation of the continuous cutting trajectory are performed on a single microcomputer. The trajectory calculation is done online i.e. after each interpolation step the cutting tool carried in the IR hand is newly positioned. The feasibility and good performance quality of the presented alternative method has been confirmed by experimental investigations using a fast rotating hard metal alloy cutting tool.

Zur Formulierung zuverlassiger Software fur zeitkritische Anwendungen fehlen in den verfugbaren Prozesprogrammiersprachen problemorientierte Sprachkonstruktionen zur Synchronisation, zur Ereignisuberwachung und zum Ausdruck des Zeitverhaltens. Die Sprache Pearl wird deshalb durch geeignete Erweiterungen, deren Syntax und Semantik beschrieben werden, entsprechend angepast. Weiterhin werden bisher noch nicht realisierte Betriebssystemdienste, die fur ein zuverlassiges und genau vorhersehbares Programmverhalten notwendig sind, und die sie steuernden Anweisungen diskutiert. Die Implementation solcher Elemente durfte ein wichtiger Schritt hin auf dem Wege zur Ermoglichung der sicherheitstechnischen Abnahme von Software sein.