Mapping feature models onto domain models: ensuring consistency of configured domain models

We present an approach to model-driven software product line engineering which is based on feature models and domain models. A feature model describes both common and varying properties of the instances of a software product line. The domain model is composed of a structural model (package and class diagrams) and a behavioral model (story diagrams). Features are mapped onto the domain model by annotating elements of the domain model with features. An element of a domain model is specific to the features included in its feature annotation. An instance of the product line is defined by a set of selected features (a feature configuration). A configuration of the domain model is built by excluding all elements whose feature set is not included in the feature configuration. To ensure consistency of the configured domain model, we define constraints on the annotations of inter-dependent domain model elements. These constraints guarantee that a model element may be selected only when the model elements are also included on which it depends. Violations of dependency constraints may be removed automatically with the help of an error repair tool which propagates features to dependent model elements.     

Fog removal using laser beam penetration,laser intensity,and geometrical features for 3D measurements in fog-filled room

Three dimension (3D) point cloud data in fog-filled environments were measured using light detection and ranging (LIDAR). Disaster response robots cannot easily navigate through such environments because this data contain false data and distance errors caused by fog. We propose a method for recognizing and removing fog based on 3D point cloud features and a distance correction method for reducing measurement errors. Laser intensity and geometrical features are used to recognize false data. However, these features are not sufficient to measure a 3D point cloud in fog-filled environments with 6 and 2 m visibility, as misjudgments occur. To reduce misjudgment, laser beam penetration features were added. Support vector machine (SVM) and K-nearest neighbor (KNN) are used to classify point cloud data into ‘fog’ and ‘objects.’ We evaluated our method in heavy fog (6 and 2 m visibility). SVM has a better F-measure than KNN; it is higher than 90% in heavy fog (6 and 2 m visibility). The distance error correction method reduces distance errors in 3D point cloud data by a maximum of 4.6%. A 3D point cloud was successfully measured using LIDAR in a fog-filled environment. Our method’s recall (90.1%) and F-measure (79.4%) confirmed its robustness.     

A graph-based algorithm for consistency maintenance in incremental and interactive integration tools

Development processes in engineering disciplines are inherently complex. Throughout the development process, the system to be built is modeled from different perspectives, on different levels of abstraction, and with different intents. Since state-of-the-art development processes are highly incremental and iterative, models of the system are not constructed in one shot; rather, they are extended and improved repeatedly. Furthermore, models are related by manifold dependencies and need to be maintained mutually consistent with respect to these dependencies. Thus, tools are urgently needed which assist developers in maintaining consistency between inter-dependent and evolving models. These tools have to operate incrementally, i.e., they have to propagate changes performed on one model into related models which are affected by these changes. In addition, they need to support user interactions in settings where the effects of changes cannot be determined automatically and deterministically. We present an algorithm for incremental and interactive consistency maintenance which meets these requirements. The algorithm is based on graphs, which are used as the data model for representing the models to be integrated, and graph transformation rules, which describe the modifications of the graphs to be performed on a high level of abstraction. This paper is an extended version of [6].     

UPGRADE: A Framework for Building Graph-Based Interactive Tools

Construction of interactive tools for visual languages is a challenging task. The UPGRADE framework leverages tool builders by integrating application logic and GUI components. It is based on attributed graphs as its internal data model. At the user interface (external representation), graphs can be rendered in multiple ways, including graphics, trees, text and tables. The framework is open, e.g., third-party viewer components may be plugged into the framework.     

Oleochemical products as building blocks for polymers

The use of oleochemical derivatives is dominated by applications in the field of surfactants and emulsifiers. There also is a remarkable amount of highly specialised uses, for example in lubricants and as additives to modify the characteristics of polymers. Besides this, some products have been developed on the basis of oleochemical building blocks in the polymer backbone. Starting with oleic acid, the difunctional azelaic acid (C-9) is produced by ozonolysis for application in high-value polyesters and polyamides. Pyrolysis of castor oil or ricinoleic acid is the commercial route to sebacic acid (C-10). Castor oil itself is used as a polyol for the production of polyurethanes. Similar polyols with modified viscosity and application characteristics are made by epoxidation and ring-opening reactions of unsaturated fatty acid derivatives. Dimer acid (C-36) is obtained by a double bond reaction of C₁₈ unsaturated fatty acids. By using hydrogenation technology, which is wellknown in the oleochemical industry to produce fatty alcohols, dimerdiols can be prepared from dimer acid. This dimerdiol is of great interest in polyurethane application fields in general, because it is a liquid, hydrophobic, long-chain raw material with two primary hydroxyl groups. By condensation of dimerdiol to building blocks with a molecular weight around 2,000 it is possible to prepare soft segments, that allow the production of thermoplastic polyurethanes (TPU) with modified application characteristics. Two different soft segments based on dimerdiol, ethers, and carbonates are discussed. The advantages for TPUs prepared from these building blocks are hydrolytic and oxidative stability and resistance to saponification and polar solvents.     

Merging of EMF models

Inadequate version control for models significantly impedes the application of model-driven software development. In particular, sophisticated support for merging model versions is urgently needed. In this paper, we present a formal approach to both two- and three-way merging of models in the EMF framework. The approach may be applied to instances of arbitrary Ecore models. We specify context-free as well as context-sensitive rules for model merging which both detect and resolve merge conflicts. Based on these rules, a merge algorithm is developed which produces a consistent model from consistent input models. The merge algorithm does neither assume unique object identifiers, nor does it require change logs. In contrast, it relies on matchings among the input models which identify common elements (state-based approach). The requirements imposed on these matchings are reduced to a minimum, e.g., there are no restrictions on the relative positions of matched elements. Altogether, the merge algorithm is widely applicable, preserves consistency, and offers advanced features, such as merging of ordered collections in the presence of arbitrary moves and handling of context-sensitive conflicts which are hard to detect and to resolve.     

Isomerizing hydroformylation of fatty acid esters: Formation of ω‐aldehydes

The isomerizing hydroformylation of fatty acid esters to oleochemicals with an additional ω‐standing aldehyde group can be performed at a relatively low temperature of 115 °C and a synthesis gas pressure of 20 bar. In the case of oleic acid ester, the best yield of linear aldehyde is 26%; in the case of linoleic acid ester, it is 34%. For both fatty compounds, a strong hydrogenation side reaction is observed, which can be explained by a steering effect of the ester group. The ester function of the fatty compounds makes hydroformylation in the surrounding area of this group impossible. Reactions with the model substances ethyl crotonate and ethyl sorbate showed that hydrogenation predominates, leading to the corresponding saturated compounds.     

Hydrolysestabile fettchemische Polyole für Polyurethananwendungen

Saponification Resistant Polyols for Polyurethane Applications Based on Oleochemical Raw Materials Fatty alcohol hydrogenation technology is used for manufacturing of interesting polyfunctional alcohols from unsaturated fatty raw materials. Two synthetic approaches are discussed: the preparation of C₂₀-alcohols with two primary and one secondary OH-group by hydrogenation of ring-opening products of epoxidized methylesters and the preparation of C₃₆-dimer fatty alcohols with two primary OH-groups, which are derived from dimer fatty acids. Requirements for special applications like high difunctionality can be achieved by using the appropriate dimer acid as starting material. These hydrophobic polyols contain no ester groups and are therefore useful for preparation of polyurethanes resistant to saponification.     

Case-based exploration of bidirectional transformations in QVT Relations

QVT Relations (QVT-R), a standard issued by the Object Management Group, is a language for the declarative specification of model transformations. This paper focuses on a particularly interesting feature of QVT-R: the declarative specification of bidirectional transformations. Rather than writing two unidirectional transformations separately, a transformation developer may provide a single relational specification which may be executed in both directions. This approach saves specification effort and ensures the consistency of forward and backward transformations. This paper explores QVT-R’s support for bidirectional model transformations through a spectrum of transformation cases. The transformation cases vary with respect to several factors such as the size of the transformation definition or the relationships between the metamodels for source and target models. The cases are solved in QVT-R, but may be applied to other bidirectional transformation languages, as well; thus, they may be used as a benchmark for comparing bidirectional transformation languages. In our work, we focus on the following research questions: functionality of bidirectional transformations in terms of relations between source and target models, solvability (which problems may be solved by a single relational specification of a bidirectional transformation), variability (does a bidirectional transformation contain varying elements, i.e., elements being specific to one direction), comprehensibility (referring to the ease of understanding and constructing QVT-R transformations), and the semantic soundness of bidirectional transformations written in QVT-R.