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Goal-oriented modeling languages have been proposed to elicit, analyze, and document high-level system requirements in the early stages of the requirements engineering (RE) process. Problems during this stage may disseminate to the subsequent stages in the software development process and artifacts. Therefore, improving the quality of goal models would improve the quality of the requirements and, consequently, the quality of the developed system. This paper proposes an approach to help modelers identify quality improvement opportunities in Goal-oriented Requirements Language (GRL) goal models. To this end, a list of GRL bad smells (i.e., bad quality symptoms) is introduced and evaluated by experts. Then, an automated rule-based technique is proposed to detect the instances of these smells. The proposed approach is evaluated using a dataset gathered from academic and real-world projects. The results show that the developed technique could successfully detect the instances of the proposed bad smells in the evaluation models. We also found that the instances of the proposed bad smells were prevalent in both academic and industrial settings. The proposed bad smells and the detection technique provide a tool to locate quality improvement opportunities in GRL goal models. [ABSTRACT FROM AUTHOR]

The electrification of road freight transport on highways using an overhead contact line system is being tested in Germany. In this study, we investigated availability of an overhead contact line system based upon unique real-world data gathered in the ELISA field test. Based on our investigation, we anticipate a high system availability in future operations. We concluded that the newness of the system can justify the longest downtimes. To confirm our findings, we first categorized causes of the downtimes. Building upon these data, we analyzed these downtimes, specifically focusing on the longest occurrences as they posed significant barriers to future operation and market implementation. Subsequently, we illustrated how the system's availability changed when individual causes of downtimes were reduced over time. Our research is paving the way to chart potential future operational scenarios. Our contribution aids decision-makers and all individuals who need to determine whether overhead contact line technology should be employed on highways in the future. [ABSTRACT FROM AUTHOR]

Abstract Object Constraint Language (OCL) is one kind of lightweight formal specification, which is widely used for software verification and validation in NASA and Object Management Group projects. Although OCL provides a simple expressive syntax, it is hard for the developers to write correctly due to lacking knowledge of the mathematical foundations of the first‐order logic, which is approximately half accurate at the first stage of development. A deep neural network named DeepOCL is proposed, which takes the unrestricted natural language as inputs and automatically outputs the best‐scored OCL candidates without requiring a domain conceptual model that is compulsively required in existing rule‐based generation approaches. To demonstrate the validity of our proposed approach, ablation experiments were conducted on a new sentence‐aligned dataset named OCLPairs. The experiments show that the proposed DeepOCL can achieve state of the art for OCL statement generation, scored 74.30 on BLEU, and greatly outperformed experienced developers by 35.19%. The proposed approach is the first deep learning approach to generate the OCL expression from the natural language. It can be further developed as a CASE tool for the software industry.

Creating accessible websites is essential to ensure the inclusion of users with disabilities, as defined in the Web Content Accessibility Guidelines (WCAG). In many countries, compliance with these guidelines is often legally mandated. Consequently, it is crucial to integrate accessibility considerations into Web development projects from the beginning. Unfortunately, accessibility requirements are often addressed only after the website is completed. To ensure compliance, it is proposed to incorporate accessibility requirements into system specifications and models. A Unified Modeling Language (UML) profile, called WebPageAcc, is introduced to streamline this process, allowing developers to incorporate accessibility requirements without extensive knowledge of accessibility standards. This profile provides stereotypes, data types, tagged values, and restrictions necessary to meet accessibility requirements. This study uses a four-stage method to create, apply, and validate the profile. Initially, an analysis of the WCAG 2.2 criteria is performed to define stereotypes, attributes and limitations aligned with the success criteria. Subsequently, the WebPageAcc profile is developed in Eclipse Papyrus, considering the identified elements. The third stage is to apply the profile to create a UML class diagram model of a real web page. Validation occurs in the final stage by executing Object Constraint Language (OCL) rules associated with attributes defined by the profile. Furthermore, an experiment is carried out to evaluate the usability difficulty of the profile among software developers. This multifaceted approach aims to improve the integration of accessibility into website development, ensuring inclusivity for a diverse user base while simplifying the implementation process for developers.

Object Constraint Language (OCL) is one kind of lightweight formal specification, which is widely used for software verification and validation in NASA and Object Management Group projects. Although OCL provides a simple expressive syntax, it is hard for the developers to write correctly due to lacking knowledge of the mathematical foundations of the first‐order logic, which is approximately half accurate at the first stage of development. A deep neural network named DeepOCL is proposed, which takes the unrestricted natural language as inputs and automatically outputs the best‐scored OCL candidates without requiring a domain conceptual model that is compulsively required in existing rule‐based generation approaches. To demonstrate the validity of our proposed approach, ablation experiments were conducted on a new sentence‐aligned dataset named OCLPairs. The experiments show that the proposed DeepOCL can achieve state of the art for OCL statement generation, scored 74.30 on BLEU, and greatly outperformed experienced developers by 35.19%. The proposed approach is the first deep learning approach to generate the OCL expression from the natural language. It can be further developed as a CASE tool for the software industry. [ABSTRACT FROM AUTHOR]

In this article, the authors review various types of cartilage injury patterns observed on magnetic resonance imaging (MRI) in professional athletes. Several examples of commonly injured joints are presented to showcase the importance of MRI in both the initial detection and characterization of cartilage lesions and the ensuing postoperative success of repair and/or restoration procedures in this unique patient population. Obtaining high-quality MRI studies, thoroughly understanding articular cartilage anatomy and pathology, and familiarizing oneself with the typical mechanisms of injury in various sports are of paramount importance to both radiologists and sports medicine clinicians alike. The authors aim to provide the reader with the foundational tools for approaching articular cartilage injuries in elite athletes and adding value to the diagnosis and treatment of these patients.

The improvement in critical reading skills (CRSs) plays a central part in college students' academic achievement, in the realization of which online collaborative learning (OCL) could perform a prominent role. This mixed-methods case study sets out to examine the influence of OCL on college students' CRSs due to the lack of research into it in the literature. To explore the impact of OCL on college students' CRSs, sophomore pre-service English teachers' (N = 42) CRSs were tested in the pre-treatment test before the start of an eight-week treatment, during which the participants critically evaluated the arguments in the pre-selected papers in groups of four, and in the post-treatment test subsequent to the intervention, constituting the quantitative data of the study. The qualitative data was collected from two qualitative surveys and a semi-structured interview. The findings obtained from the analysis of the quantitative data revealed that a statistically significant difference existed between the pre- and post-treatment test results, originating from the higher scores the participants got on the post-treatment test. The findings on the qualitative data demonstrated that the participants held positive views about the treatment and believed their CRSs developed considerably by virtue of immersing in OCL. [ABSTRACT FROM AUTHOR]

Quality communication is a major challenges in large-scale and distributed smart grid applications. Several protocols and middleware have been proposed to address communication quality issues in those applications. DDS is a standard data-centric middleware for publish/subscribe communication. It has been proposed for smart grid to address both connectivity and communication quality issues. DDS provides multiple quality of service (QoS) policies to address reliability, latency, and data availability. One of the main challenges in adopting the standard in smart grids is the complexity of adopting and tailoring its QoS policies. This is because those policies are described informally introducing ambiguities, which hinders the precise implementation of DDS. To address this, we formalize the descriptions of DDS QoS policies using the object constraint language (OCL). We also clearly defined the design structural relations among DDS entities and QoS policies. In the process, we analyzed the dependencies among QoS policies and we built clear and concise structural relations. We then proposed feature modeling and a management layer to facilitate QoS tuning and to reduce development and configuration complexity. We implemented the proposed approach in a simulated power consumption domain. The results show that the approach improves the development process. They also show that the approach significantly improves the performance of DDS-enabled applications. [ABSTRACT FROM AUTHOR]

Software tool extension is a long-standing problem. The simplest kind of extension is to add, to an existing tool, new custom tabs that invoke extension programs for viewing the data in a novel way. However even this task is not simple and roughly speaking every advanced tool does this in its own way. The goal of this paper is to develop a unified method of adding new custom tabs for tools whose back-end is deployed on a data server, but the front-end is browser-based (HTML web pages). More precisely, adding custom tabs is considered, to define new views of data stored on the Data server. The instrument used in this paper will be the Interaction Flow Modeling Language (IFML) designed for building precise Platform Independent Models (PIMs) for the described systems. The proposed extension method will be explained on a Deep Learning Lifecycle Data Management (DL LDM) task: first build a simple DL LDM base tool which is already practically usable, then add a PLUS component which permits the end-user to define new views of back-end data in a relatively simple way (without using the internal implementation of the base tool). [ABSTRACT FROM AUTHOR]

Tolerance analysis is a key engineering task that is usually supported by domain-specific analysis models and tools that are generally not connected to the system functionality. The model-based system engineering (MBSE) approach is a potential solution to this limitation, but it has not yet been deeply explored in this type of mechanical analysis, for which some problems need to be explored. One of these issues is the capacity of languages such as SysML to describe solution principles based on active surfaces that participate in functionality and are present for tolerance analysis. Thus, this study explored the possibilities that enable SysML to represent these geometries and their mathematical relationships based on Topologically and Technologically Related Surfaces (TTRS) theory and aligned with Geometric Dimensioning and Tolerancing (GD&T) standards. Additionally, the capacity of SysML to assure the consistency of tolerance analysis models is also explored, due to the limitations identified in analysis languages like Modelica. In this context, this paper presents a SysML profile for tolerance analysis modeling (SysML4TA), containing domain-specific semantics (concepts and constraints) to assure the completeness of the analysis models and consistency between the different models considered in the integrated model of the system. Finally, a case study applied to a manufacturing context is presented to validate the capacity of SysML to solve the identified problems. [ABSTRACT FROM AUTHOR]

Software testing is one activity for Software Quality Assurance (SQA). One way to test is through Black box test cases at design level. Since UML is a de-facto design language and is one of the most used design language now a day. Therefore, there is need to design black box test cases using UML behavioral diagrams. Object Constraint Language (OCL) is a formal language to write constraints on UML diagrams as it is unambiguous. Although test cases against robustness have been designed through OCL expressions but no test cases as yet have been designed against security specific authentication, access control and availability. Specification and testing of security specific authentication, access Control and availability through OCL. An experiment is performed with a hypothesis 'if Security Specific Authentication, Access Control and Availability is specified through OCL in state diagram then Test cases can be designed'. We have specified security in OCL then same OCL expressions are used to model security in UML state diagram. Furthermore, mutation testing is performed on OCL expressions. Then ECP is done using same extracted mutants. Security specific authentication, access control and availability is specified in OCL and then test cases are designed using a black box testing technique Equivalence Class Partitioning. Hypothesis results shows that one can design test cases through OCL. This thesis shows that Specification and Testing of Security specific authentication, access control and availability through OCL. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Guangxi Normal University - Natural Science Edition is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In software modeling, UML (Unified modeling language) receives increasing attention from designers of real-time systems in software development. The emergence of temporal database calls for new visual and efficient modeling techniques to facilitate the design of temporal objects. Even though UML is not currently equipped to manage this task, UML and extended extension offered limited means to express time-varying data and temporal constraints over the dynamic behavior of temporal objects. Therefore, the object constraint language (OCL) plays an important role in the elaboration of the correct conceptual schema that allows the definition of the restrictions and the constraints which contain the duplicate and complex expression. In this paper, we present a UML extension enriched by OCL features and Bitemporal dimension to improve the understandability of a UML/OCL model, and its ability to support the temporal attributes and their evolution. The proposed temporal UML/OCL based on Bitemporal data will be translating into their corresponding in a temporal object-Relational database for the purpose of tracking historical information with an efficient manner. An algorithm has been proposed to automate the transformation from the conceptual schema enriched by bitemporal features to temporal object relational database model by following different steps such as classifying and extracting information about classes, relationships and attributes.

Tolerance analysis is a key engineering task that is usually supported by domain-specific analysis models and tools that are generally not connected to the system functionality. The model-based system engineering (MBSE) approach is a potential solution to this limitation, but it has not yet been deeply explored in this type of mechanical analysis, for which some problems need to be explored. One of these issues is the capacity of languages such as SysML to describe solution principles based on active surfaces that participate in functionality and are present for tolerance analysis. Thus, this study explored the possibilities that enable SysML to represent these geometries and their mathematical relationships based on Topologically and Technologically Related Surfaces (TTRS) theory and aligned with Geometric Dimensioning and Tolerancing (GD&T) standards. Additionally, the capacity of SysML to assure the consistency of tolerance analysis models is also explored, due to the limitations identified in analysis languages like Modelica. In this context, this paper presents a SysML profile for tolerance analysis modeling (SysML4TA), containing domain-specific semantics (concepts and constraints) to assure the completeness of the analysis models and consistency between the different models considered in the integrated model of the system. Finally, a case study applied to a manufacturing context is presented to validate the capacity of SysML to solve the identified problems.

Summary: Although software libraries promote code reuse and facilitate software development, they increase the complexity of programme analysis tasks. To effectively analyse programmes built on top of software libraries, it is essential to have specifications for the library methods that can be easily processed by analysis tools. However, the availability of such specifications is seriously limited at the moment. Manually writing the specifications can be prohibitively expensive and error‐prone, while existing automated approaches to inferring the specifications seldom produce results that are strong enough to be used in programme analysis. In this work, we propose the Doc2smt approach to generating strong functional constraints in SMT for library methods based on their documentations. Doc2smt first applies natural language processing (NLP) techniques and a set of rules to translate a method's natural language documentation into a large number of candidate constraint clauses in OCL. Then, it utilizes a manually enhanced domain model to identify OCL candidate constraint clauses that comply with the problem domain in static validation, translates well‐formed OCL constraints into the SMT‐LIB format, and checks whether each SMB‐LIB constraint rightly abstracts the functionalities of the method under consideration via testing in dynamic validation. In the end, it reports the first functional constraint that survives both validations to the user as the result. We have implemented the approach into a supporting tool with the same name. In experiments conducted on 451 methods from the Java Collections Framework and the Java IO library, Doc2smt generated correct constraints for 309 methods, with the average generation time for each correct constraint being merely 2.7 min. We have also applied the generated constraints to facilitate symbolic‐execution‐based test generation with the Symbolic Java PathFinder (SPF) tool. For 24 utility methods manipulating Java container and IO objects, SPF with access to the generated constraints produced 51.2 times more test cases than SPF without the access. [ABSTRACT FROM AUTHOR]

Background: The aim of this study is to systematically review the literature on clinical outcomes of patients who have undergone autologous matrix-induced chondrogenesis (AMIC) for treatment of osteochondral lesions of the talus (OCL) and compare the studies' outcomes.Methods: Pubmed and Embase were searched in January 2020 for articles concerning OCL surgery. Studies were included if they had a minimum 1-year follow-up and the primary measures were functional outcomes. The meta-analysis compared the Visual Analogic Score (VAS), the American Orthopedic Foot and Ankle Score (AOFAS), and the Foot Function Index (FFI) between baseline and follow-up of 1-2years, and 3-5years. A random effects model was used to evaluate outcome changes.Results: The search returned 15 studies, with a total of 492 patients. The VAS improved 4.45 and 4.6 points from baseline to the 1-2year and 3-5yearfollow-up, respectively (p<0.001). AOFAS improved 31.59 and 32.47 points from baseline to the 1-2year and 3-5yearfollow-up, respectively (p<0.001). The FFI showed a significant improvement of 30.93 points from baseline to year 3-5 (p<0.001). A total of 6 patients with revision surgeries have been reported within the follow up period. It was not possible to correlate clinical features like lesion size, surgical approach, and bone marrow stimulation technique to the reported outcome.Conclusion: Surgical treatment of OCL via the AMIC procedure provided significant improvement in the functional outcome and pain scores when compared to the pre-operative values. Improvements were observed up to 5years post-operatively. [ABSTRACT FROM AUTHOR]

Model-based software engineering gains further attention these days. To better support it, the use of constraint languages is important in order to bridge expressiveness gaps and eliminate ambiguity. Nevertheless, the use of model-based constraint languages, like the Object Constraint Language (OCL), is quite limited and the specification of constraints is left to the implementation stage. One option for these practices might be the misconception that model-based constraint languages are difficult to work with. In this paper, we examine the usages of representative constraint languages, namely OCL, for model-based constraint languages, and Java, for implementation-based constraint languages. In particular, we examine their usage in understanding and developing constraints. We evaluate these usages via a controlled experiment with 110 Information Systems Engineering undergraduate students. We found out that using OCL outperforms using Java for both understanding and developing constraints. Yet, the students had more confidence with Java. The results indicate that the aforementioned misconception is wrong and there is a need for further education regarding model-based constraints languages, so to get more practice and confidence. [ABSTRACT FROM AUTHOR]

Ensuring the satisfaction of security requirements is one of the most vital needs in developing different types of systems. Therefore, it is necessary to apply a method to accurately define security requirements and then, verify them in the design phase before starting system development. One of the key information security requirements is availability of system functionalities for authorized users. This type of requirement is especially important in real-time embedded systems (RTESs) because they are associated with hard temporal needs and deadlines, and if they are not satisfied the main functionality of the system will be interrupted. To make sure that the availability properties are correctly considered in the design of a system, a language is needed to specify different temporal constraints. This language should be applicable for system designers who do not have sufficient formal and mathematical knowledge. OCL is a high-level constraint specification language (based on UML modeling language) which is widely used by system designer teams, and therefore, it is appropriate for this purpose. However, OCL does not support specification of temporal properties. In this paper, using a hybrid logic-based and pattern-based approach, a language grammar based on OCL, named RTSL has been proposed. RTSL is able to specify different real-time temporal properties. To achieve this goal, we developed a comprehensive property specification pattern system which considers all qualitative, quantitative and probabilistic property patterns that is used as a guideline for property specification and language development. [ABSTRACT FROM AUTHOR]

OCL is widely used by model-driven engineering tools with different purposes like writing integrity constraints for meta-models, as a navigation language in model transformation languages or to define transformation specifications. Another scenario is the automatic generation of OCL code by a repair system. These generated expressions tend to be complex and unreadable due to the nature of the generative process. However, to be useful this code should be simple and resemble manually written code as much as possible when a developer must manually maintain it. There exists refactorings approaches for manually written OCL code, but there is no tool targeted to the optimisation of OCL expressions which have been automatically synthesised. Moreover, there is no available catalogue of OCL refactorings which can be integrated seamlessly into a tool. In this work, we contribute a set of refactorings intended to optimise OCL expressions, notably covering cases likely to arise in generated OCL code. We also contribute the implementation of these refactorings, built as a generic transformation catalogue using bentō, a transformation reuse tool for ATL. This makes it possible to specialise the catalogue for any OCL variant based on Ecore. Moreover, we propose a method to verify the correctness of the implemented catalogue based on translation validation and model finding. We describe the design and implementation of the catalogue and evaluate it by optimising a large amount of OCL expressions and proving the correctness of each optimisation execution. We also derive working implementations of the catalogue for ATL, EMF/OCL and SimpleOCL made available in a tool called BeautyOCL. [ABSTRACT FROM AUTHOR]

The correct representation of the relevant properties of a system is an essential requirement for the effective use and wide adoption of model-based practices in industry. Uncertainty is one of the inherent properties of any measurement or estimation that is obtained in any physical setting; as such, it must be considered when modeling software systems deal with real data. Although a few modeling languages enable the representation of measurement uncertainty, these aspects are not normally incorporated into their type systems. Therefore, operating with uncertain values and propagating their uncertainty become cumbersome processes, which hinder their realization in real environments. This paper proposes an extension of OCL/UML primitive datatypes that enables the representation of the uncertainty that comes from physical measurements or user estimates into the models, together with an algebra of operations that are defined for the values of these types. [ABSTRACT FROM AUTHOR]

In software modeling, UML (Unified modeling language) receives increasing attention from designers of real-time systems in software development. The emergence of temporal database calls for new visual and efficient modeling techniques to facilitate the design of temporal objects. Even though UML is not currently equipped to manage this task, UML and extended extension offered limited means to express time-varying data and temporal constraints over the dynamic behavior of temporal objects. Therefore, the object constraint language (OCL) plays an important role in the elaboration of the correct conceptual schema that allows the definition of the restrictions and the constraints which contain the duplicate and complex expression. In this paper, we present a UML extension enriched by OCL features and Bitemporal dimension to improve the understandability of a UML/OCL model, and its ability to support the temporal attributes and their evolution. The proposed temporal UML/OCL based on Bitemporal data will be translating into their corresponding in a temporal object-Relational database for the purpose of tracking historical information with an efficient manner. An algorithm has been proposed to automate the transformation from the conceptual schema enriched by bitemporal features to temporal object relational database model by following different steps such as classifying and extracting information about classes, relationships and attributes. [ABSTRACT FROM AUTHOR]