Constraint Language Research Articles

Validating EHR clinical models using ontology patterns

Clinical models are artefacts that specify how information is structured in electronic health records (EHRs). However, the makeup of clinical models is not guided by any formal constraint beyond a semantically vague information model. We address this gap by advocating ontology design patterns as a mechanism that makes the semantics of clinical models explicit.This paper demonstrates how ontology design patterns can validate existing clinical models using SHACL. Based on the Clinical Information Modelling Initiative (CIMI), we show how ontology patterns detect both modeling and terminology binding errors in CIMI models.SHACL, a W3C constraint language for the validation of RDF graphs, builds on the concept of “Shape”, a description of data in terms of expected cardinalities, datatypes and other restrictions. SHACL, as opposed to OWL, subscribes to the Closed World Assumption (CWA) and is therefore more suitable for the validation of clinical models.We have demonstrated the feasibility of the approach by manually describing the correspondences between six CIMI clinical models represented in RDF and two SHACL ontology design patterns. Using a Java-based SHACL implementation, we found at least eleven modeling and binding errors within these CIMI models. This demonstrates the usefulness of ontology design patterns not only as a modeling tool but also as a tool for validation.

Automated String Constraints Solving for Programs Containing String Manipulation Functions

The ability to solve various constraints is a principal factor of automatic constraint solvers. Most object-oriented languages treat a character string as a primitive data type which is manipulated by string library functions. Most constraint solvers have limitations on their input constraints, such as strong restrictions on the expressiveness of constraints or lack of the ability to solve hybrid constraints. These limitations hinder applying automated constraint solvers on program analysis techniques for programs containing strings and string manipulation functions. We propose an approach to automatically solve program constraints involving strings and string manipulation functions. Based on the character array model, we design a constraint language which contains primitive operations to precisely describe the constraints of commonly used string manipulation functions. The translated string constraints together with numeric constraints are then solved by a two-phase test generation procedure: firstly, a partial solution is obtained to satisfy the arithmetic constraints of the position variables, and the solution is utilized to simplify the string constraints into pure character array constraints; secondly, the pure array constraints are solved by an off-the-shelf array-specific theory based constraint solver. We integrate the approach into an automated testing tool to support the generation of string test cases, and then perform experiments. The results of the experiments prove that the integration of the proposed approach promotes the testing coverage of the existing testing tool, and the integrated tool has an advantage of handling specific string manipulation functions compared with an existing string solver.

Curriculum Delivery Constraints of Arabic Language as a Foreign Language in the UAE

Curriculum Delivery Constraints of Arabic Language as a Foreign Language in the UAE

The introspective may achieve more: Enhancing existing Geoscientific models with native-language emulated structural reflection

Geoscientific models manage myriad and increasingly complex data structures as trans-disciplinary models are integrated. They often incur significant redundancy with cross-cutting tasks. Reflection, the ability of a program to inspect and modify its structure and behavior at runtime, is known as a powerful tool to improve code reusability, abstraction, and separation of concerns. Reflection is rarely adopted in high-performance Geoscientific models, especially with Fortran, where it was previously deemed implausible. Practical constraints of language and legacy often limit us to feather-weight, native-language solutions. We demonstrate the usefulness of a structural-reflection-emulating, dynamically-linked metaObjects, gd. We show real-world examples including data structure self-assembly, effortless input/output (IO) and upgrade to parallel I/O, recursive actions and batch operations. We share gd and a derived module that reproduces MATLAB-like structure in Fortran and C++. We suggest that both a gd representation and a Fortran-native representation are maintained to access the data, each for separate purposes. Embracing emulated reflection allows generically-written codes that are highly re-usable across projects.

SHErrLoc

We introduce a general way to locate programmer mistakes that are detected by static analyses. The program analysis is expressed in a general constraint language that is powerful enough to model type checking, information flow analysis, dataflow analysis, and points-to analysis. Mistakes in program analysis result in unsatisfiable constraints. Given an unsatisfiable system of constraints, both satisfiable and unsatisfiable constraints are analyzed to identify the program expressions most likely to be the cause of unsatisfiability. The likelihood of different error explanations is evaluated under the assumption that the programmer’s code is mostly correct, so the simplest explanations are chosen, following Bayesian principles. For analyses that rely on programmer-stated assumptions, the diagnosis also identifies assumptions likely to have been omitted. The new error diagnosis approach has been implemented as a tool called SHErrLoc, which is applied to three very different program analyses, such as type inference for a highly expressive type system implemented by the Glasgow Haskell Compiler—including type classes, Generalized Algebraic Data Types (GADTs), and type families. The effectiveness of the approach is evaluated using previously collected programs containing errors. The results show that when compared to existing compilers and other tools, SHErrLoc consistently identifies the location of programmer errors significantly more accurately, without any language-specific heuristics.

DCL 2.0: modular and reusable specification of architectural constraints

BackgroundDue to the abstract nature of software architecture concepts, ensuring the correct implementation of architectural decisions is not a trivial task. Divergences between the planned architecture and source code may occur in the early stages of the software development, which denotes a phenomenon known as software architecture erosion. Architectural conformance checking techniques have been proposed to tackle the problem of divergences between the planned architecture and source code. Among such techniques, we can note the DCL (dependency constraint language), which is a domain-specific language that has interesting results in architectural conformance contexts. However, the current version of DCL has some limitations, such as lack of modularity and low degree of reuse, which may prevent its adoption in real software development scenarios. In this article, we extend DCL with a reusable, modular, and hierarchical specification.MethodWe propose and evaluate DCL 2.0—an extension of the original DCL—and its tool in a real-world development scenario of a large system used by a government branch of Minas Gerais, Brazil.ResultWe were able to detect 771 architectural violations where 74% of them could only be detected due to the new violation types proposed in DCL 2.0.ConclusionBy using DCL 2.0 herein presented, it was possible to conclude the following: (i) DCL 2.0 proved importance in helping the development team consistently address violations, and (ii) after using DCL 2.0 for months, the number of architectural violations being committed into the system branches was reduced to zero. Therefore, we argue that DCL 2.0 can have a positive impact on the architectural conformance of systems.

IOCL: An interactive tool for specifying, validating and evaluating OCL constraints

The Object Constraint Language (OCL) is commonly used for specifying additional constraints on models, in addition, to the ones enforced by the semantics of the models. However, a lot of practitioners and even researchers are reluctant in using OCL to some extent due to the lack of sufficient familiarity with OCL. To facilitate practitioners and researchers in specifying OCL constraints, we designed and developed a web-based tool called interactive OCL (iOCL) for interactively specifying constraints on a given model. The core idea behind iOCL is to present and display only relevant details (e.g., operations) of OCL to users at a given step of constraint specification process, in addition to helping modelers with its syntax. We evaluated iOCL using a real-world case study from Cancer Registry of Norway and the results showed that iOCL can significantly reduce the time required to specify OCL constraints and decrease the possibility of making syntactic errors during the specification process. Thus, we conclude that iOCL can facilitate the process of OCL constraint specification. Interested users can try iOCL at: http://iocl.zen-tools.com/ . • iOCL specifies OCL constraints in an interactive manner. • iOCL dynamically interacts with users and only displays relevant details of OCL. • iOCL can help users to check the syntax of specified constraints. • iOCL was evaluated with a real-world case study from the Cancer Registry of Norway; • iOCL reduces the time of specifying OCL constraints and syntactic errors.

Chromar, a language of parameterised agents

Modelling in biology becomes necessary when systems are complex. However, the more complex the systems are, the harder models become to read and write. The most common ways of writing models are by writing reactions on species (discrete objects), or by writing rate equations for the populations of such species. One problem with such approaches is that the number of species is often so large that the model cannot be realistically enumerated. Another problem is that the number of species and reactions often fixed by default, whereas new variations of species and reactions are constantly being improvised by evolution in the long-term and moment to moment by the changing chemical environments and compartments living organisms inhabit and create within.Here we develop a modelling language Chromar that provides an extension to the representation of reactions, in which objects, called agents, carry attributes with associated types — for example, Leaf agents all have a mass attribute. Dynamics are given by stochastic rules defined on groups of agents — for example all agents of a specific type — and so enumerating the dynamics of each agent is not necessary. This compact representation addresses the first problem. Having a more compact representation can also help make models a tool for knowledge representation and exchange instead of just simulation. Further, if we think of agents as the analogue of species in reactions, then creating a new agent of some type effectively creates a new species, thereby addressing the second problem.We then develop an extension of Chromar equipped with deterministically changing time-dependent values (fluents) and aggregate values computed from the state of the system (observables). Fluents are useful for describing the context of the system, which is rarely static; observables are useful in abstracting away details of system behaviour and providing a way to observe the system during simulation.Finally, we develop an embedding of Chromar (and its extensions) in the programming language Haskell and demonstrate its applicability via two examples. Embedding Chromar in a general purpose programming language such as Haskell eases some of the constraints of modelling languages while still maintaining the naturalness of a domain-specific language.

On the Parameterized Complexity of Finding Small Unsatisfiable Subsets of CNF Formulas and CSP Instances

In many practical settings it is useful to find a small unsatisfiable subset of a given unsatisfiable set of constraints. We study this problem from a parameterized complexity perspective, taking the size of the unsatisfiable subset as the natural parameter where the set of constraints is either (i) given a set of clauses, i.e., a formula in conjunctive normal Form (CNF), or (ii) as an instance of the Constraint Satisfaction Problem (CSP). In general, the problem is fixed-parameter in tractable. For an instance of the propositional satisfiability problem (SAT), it was known to be W[1]-complete. We establish A[2]-completeness for CSP instances, where A[2]-hardness prevails already for the Boolean case. With these fixed-parameter intractability results for the general case in mind, we consider various restricted classes of inputs and draw a detailed complexity landscape. It turns out that often Boolean CSP and CNF formulas behave similarly, but we also identify notable exceptions to this rule. The main part of this article is dedicated to classes of inputs that are induced by Boolean constraint languages that Schaefer [1978] identified as the maximal constraint languages with a tractable satisfiability problem. We show that for the CSP setting, the problem of finding small unsatisfiable subsets remains fixed-parameter intractable for all Schaefer languages for which the problem is non-trivial. We show that this is also the case for CNF formulas with the exception of the class of bijunctive (Krom) formulas, which allows for an identification of a small unsatisfiable subset in polynomial time. In addition, we consider various restricted classes of inputs with bounds on the maximum number of times that a variable occurs (the degree), bounds on the arity of constraints, and bounds on the domain size. For the case of CNF formulas, we show that restricting the degree is enough to obtain fixed-parameter tractability, whereas for the case of CSP instances, one needs to restrict the degree, the arity, and the domain size simultaneously to establish fixed-parameter tractability. Finally, we relate the problem of finding small unsatisfiable subsets of a set of constraints to the problem of identifying whether a given variable-value assignment is entailed or forbidden already by a small subset of constraints. Moreover, we use the connection between the two problems to establish similar parameterized complexity results also for the latter problem.

A two-fold rule-based model for aspect extraction

Abstract Opinion target extraction or aspect extraction is the most important subtask of the aspect-based sentiment analysis. This task focuses on the identification of the targets of user's opinions or sentiments from online reviews. In the recent years, syntactic patterns-based approaches have performed quite well and produced significant improvement in the aspect extraction task. However, these approaches are heavily dependent on the dependency parsers which produced syntactic relations following the grammatical rules and language constraints. In contemporary, users do not give much importance to these rules and constraints while expressing their opinions about particular product and neither reviewer websites restrict users to do so. This makes syntactic patterns-based approaches vulnerable. Therefore, in this paper, we are proposing a two-fold rules-based model (TF-RBM) which uses rules defined on the basis of sequential patterns mined from customer reviews. The first fold extracts aspects associated with domain independent opinions and the second fold extracts aspects associated with domain dependent opinions. We have also applied frequency- and similarity-based approaches to improve the aspect extraction accuracy of the proposed model. Our experimental evaluation has shown better results as compared with the state-of-the-art and most recent approaches.

An UML profile for representing real-time design patterns

Systems which manipulate important volumes of data need to be managed with Real-Time (RT) databases. These systems are subject to several temporal constraints related to data and to transactions. Thus, their design remains a complex task. To remedy this complexity, it is necessary to integrate design methods to support data and transactions temporal constraints. Among the design methods, those based on patterns have been widely used in several fields. However, despite their advantages, these patterns present some shortcomings. Indeed, they do not manage efficiently the patterns variability and they do not specify the pattern elements when they are instantiated. To overcome these limitations, we propose, in this paper, a new UML profile to (i) express the variability in patterns and (ii) to identify the pattern elements in its instance. Besides, in order to well-capture the knowledge of the domain, the proposed profile extends UML with concepts related to real-time databases and integrates OCL (Object Constraint Language) to enforce the variation points consistency. Finally, we give an example of a RT pattern that illustrates these UML extensions, where we implement the proposed profile and we validate the pattern diagrams using the constraints we have proposed.

MISTAKES IN AUDIOVISUAL TRANSLATION: LINGUISTIC AND DIDACTIC ASPECTS

Introduction: Mistakes in audiovisual translation are generally caused by a wide rangeof lingual and extralingual factors. Translators’ unawareness of the nature of these factors hampersthe process of translation and results in misinterpretation of the message by the addressee.With fansubbing and crowdsourcing spreading worldwide, more and more experts are becomingconcerned with poor quality translations sprouting up before or simultaneously with theprofessionally interpreted or dubbed versions. Ukraine seems to have finally overcome the hardlycomprehensible voiceover of pirate DVDs (a sad legacy of the early 1990s). However, Ukrainianaudience is still struggling to understand some of the ‘quick fix’ versions of TV series, whichappear to be too numerous to be properly translated.Purpose: The objective of the article is to analyze typical mistakes that can occurin audiovisual translation and to outline the major causes of these mistakes.Methods: The research is based on randomly selected cases of inadequate voiceovertranslation of English fiction and documentary series into Ukrainian and Russian. The choiceof the films was prompted by the commentaries of Internet-users who indicated insufficientquality of translation of these films. Mistakes found were then analyzed from the point of viewof language and culture-specific constraints, interpreting mode constraints and personal constraintsthat might have affected the translator’s choice.Results: Apart from widely known linguistic phenomena of polysemy, homonymy,lexical lacunas, there are other stumbling blocks to faithful translation, such as lack of attentionto historical and cultural context, inappropriate stylistic toning, thematic irrelevance, and even blunt incoherence of verbal and visual features, etc. Due to the multimode nature of audiovisualtranslations some of the problems could easily be solved if translators actually watched the film,instead of hastily working on the script.Conclusions: Similar analysis of translators’mistakes is suggested as a means of teachingnovice translators to develop efficient tools of overcoming difficult cases while translatingforeign films.

Patient safety during procedural sedation using capnography monitoring: a systematic review and meta-analysis

ObjectiveTo evaluate the effect of capnography monitoring on sedation-related adverse events during procedural sedation and analgesia (PSA) administered for ambulatory surgery relative to visual assessment and pulse oximetry alone.Design and...

Traduire l’« agrammaticalité » durassienne : liberté ou contrainte ?

AbstractThis paper explores the constraints language deconstruction and ungrammaticality in Margerite Duras’s novels impose on the translation process. Given its “value” in Duras’s work, ungrammaticality seems to dictate the translator’s choice of literal translation to English or Spanish, except when the differences between language systems do not allow for literal translation and require creative ways to capture the source text and its effects. However, a review of several published English and Spanish translations of Duras’s novels has revealed that a more powerful constraint is imposed on translation and conflicts with the above-mentioned mechanism. This fundamental constraint is the acceptability of the proposed translation by the target culture.

PHENOMENOLOGICAL STUDY ON THE ADAPTABILITY OF INTERNATIONAL STUDENTS TO CONSERVATION-BASED CURRICULUM AT UNIVERSITAS NEGERI SEMARANG

Universitas Negeri Semarang (UNNES) has a vision as a conservation university with international reputation. Therefore, UNNES implements learning activity by applying character development of conservation. In developing the character of the entire academic community, UNNES applies transformative learning by changing the orientation of anthropocentrism to eco-centrism learning (constructivism and cooperative approach in line with the eco-centrism orientation), from selfishness to collectivism, and materialism to spiritualism. Furthermore, UNNES uses learning strategies includingrole model, habituation, reinforcement, and reflective thinking. This study aims to identify and analyze the adaptability of international students in both academic and social issues related to conservation-based curriculum at UNNES. Participants in this study were 52 students from 13 countries. This research used descriptive qualitative by phenomenological approach. Whereas, the data was obtained from observation and in-depth interview. Perception of international student to the curriculum in UNNES is described and expected to be used as a platform for policy makers to make innovations in an attempt to create UNNES as a conservation university with international reputation. Based on the results, international students can adapt well in UNNES environment, both in academic and social issues. International students are able to understand and implement 8 conservation characters of UNNES; there are inspiring, humane, caring, innovative, creative, fair play, honest and fair. Theyalso appreciate the concept of Student Centre Learning (SCL) in UNNES and stated that the learning principles have been well implemented in UNNES. Nevertheless, language remains a constraint and thus interactive and participatory principles may not be implemented optimally. Hence, lecturers are expectedto improve their English skill to overcome this language constraint and create participative communication with their international students. Also, International Office (IO) may need to further demonstrate its role in creating mutual understanding between the two parties and providing facilities for international students to adapt in UNNES environment, since the international students have not gain significant benefit from its existence.

Recalibrating the Gaze

If symbolic language, collective learning, and the means by which we use technology are humanity’s “fundamental, non-genetic, adaptive capacity,” then how these are extended and modified in the next few decades will fundamentally define what it means to be human in the twenty-first century. The scale and scope of that determination is, in turn, dependent on how cognitive framings or “gazes,” shaped by shared conceptions of time, are constructed, for these gazes bound conversation, available knowledge, and the contextualizing of decisions. This article argues that the dominant linear orientation with its present-future emphasis has a direct causal relationship with the existential issues contemporary society faces. It postulates their resolution requires going beyond existing constraints in language and learning together with the need to fundamentally rethink many explicit and tacit understandings, including those that inform futures thinking. If this were to occur, then the scope of symbolic language is broadened, thus, allowing a wider range of options to become available. However, it must be recognized at the same time that these same elements must morph to reflect both the inclusion, yet incompleteness, of all knowledge systems into a new ecology of understanding. Such propositions lead to a question: does contemporary society have sufficient awareness of its present situation to put aside (even for a while) what has made it successful thus far, to even consider possibilities that exist beyond the conventions it now accepts as axiomatic?

Automated Generation of OCL Constraints: NL based Approach vs Pattern Based Approach

This paper presents an approach used for automated generations of software constraints. In this model, the SBVR (Semantics of Business Vocabulary and Rules) based semi-formal representation is obtained from the syntactic and semantic analysis of a NL (Natural Language) (such as English) sentence. A SBVR representation is easy to translate to other formal languages as SBVR is based on higher-order logic like other formal languages such as OCL (Object Constraint Language). The proposed model endows with a systematic and powerful system of incorporating NL knowledge on the formal languages. A prototype is constructed in Java (an Eclipse plug-in) as a proof of the concept. The performance was tested for a few sample texts taken from existing research thesis reports and books.

Web 2.0 applications in the workplace: How to ensure their proper use?

There is an ongoing debate about the role of Web 2.0 applications (e.g., Facebook™ and Instagram™) in the workplace. Indeed, misuse cases of these applications are on the rise and many enterprises still have concerns with their real benefits and values and thus, have been reluctant to adopting them. This paper addresses these concerns by developing restrictions over the social actions that Web 2.0 applications allow users to perform. These restrictions permit to limit for instance, the number of times a social action is performed, the content of a social action, and the recipient of a social action. The restrictions are specified in UML Object Constraint Language and enforced through a run-time monitoring that permits to detect violations. This paper, also, presents an implementation of restrictions over Hangouts™ as an illustrative Web 2.0 application.

Modelling System of Systems Interface Contract Behaviour

A key challenge in System of Systems (SoS) engineering is the analysis and maintenance of global properties under SoS evolution, and the integration of new constituent elements. There is a need to model the constituent systems composing a SoS in order to allow the analysis of emergent behaviours at the SoS boundary. The Contract pattern allows the engineer to specify constrained behaviours to which constituent systems are required to conform in order to be a part of the SoS. However, the Contract pattern faces some limitations in terms of its accessibility and suitability for verifying contract compatibility. To address these deficiencies, we propose the enrichment of the Contract pattern, which hitherto has been defined using SysML and the COMPASS Modelling Language (CML), by utilising SysML and Object Constraint Language (OCL). In addition, we examine the potential of interface automata, a notation for improving loose coupling between interfaces of constituent systems defined according to the contract, as a means of enabling the verification of contract compatibility. The approach is demonstrated using a case study in audio/video content streaming.

Discovering Archipelagos of Tractability for Constraint Satisfaction and Counting

The Constraint Satisfaction Problem (CSP) is a central and generic computational problem which provides a common framework for many theoretical and practical applications. A central line of research is concerned with the identification of classes of instances for which CSP can be solved in polynomial time; such classes are often called “islands of tractability.” A prominent way of defining islands of tractability for CSP is to restrict the relations that may occur in the constraints to a fixed set, called a constraint language , whereas a constraint language is conservative if it contains all unary relations. Schaefer’s famous Dichotomy Theorem (STOC 1978) identifies all islands of tractability in terms of tractable constraint languages over a Boolean domain of values. Since then, many extensions and generalizations of this result have been obtained. Recently, Bulatov (TOCL 2011, JACM 2013) gave a full characterization of all islands of tractability for CSP and the counting version #CSP that are defined in terms of conservative constraint languages. This article addresses the general limit of the mentioned tractability results for CSP and #CSP, that they only apply to instances where all constraints belong to a single tractable language (in general, the union of two tractable languages is not tractable). We show that we can overcome this limitation as long as we keep some control of how constraints over the various considered tractable languages interact with each other. For this purpose, we utilize the notion of a strong backdoor of a CSP instance, as introduced by Williams et al. (IJCAI 2003), which is a set of variables that when instantiated, moves the instance to an island of tractability, that is, to a tractable class of instances. We consider strong backdoors into scattered classes , consisting of CSP instances where each connected component belongs entirely to some class from a list of tractable classes. Figuratively speaking, a scattered class constitutes an archipelago of tractability . The main difficulty lies in finding a strong backdoor of given size k ; once it is found, we can try all possible instantiations of the backdoor variables and apply the polynomial time algorithms associated with the islands of tractability on the list component-wise. Our main result is an algorithm that, given a CSP instance with n variables, finds in time f ( k ) n O (1) a strong backdoor into a scattered class (associated with a list of finite conservative constraint languages) of size k or correctly decides that there is not such a backdoor. This also gives the running time for solving (#)CSP, provided that (#)CSP is polynomial-time tractable for the considered constraint languages. Our result makes significant progress towards the main goal of the backdoor-based approach to CSPs—the identification of maximal base classes for which small backdoors can be detected efficiently.