László Lengyel

László Lengyel
Budapest University of Technology and Economics · Department of Automation and Applied Informatics

PhD

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162
Publications
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1,113
Citations

Publications

Publications (162)
Article
The present paper serves as a demonstration how an in-line PAT tool can be used for rapid and efficient process development in a fully continuous powder to granule line consisting of an interconnected twin-screw wet granulator, vibrational fluid bed dryer, and a regranulating mill. A new method was investigated for the periodic in-line particle siz...
Article
The present paper reports the first monitoring and control of ultra-low dose powder feeding using a camera image-based mass flow measurement system. Caffeine was fed via a single-screw microfeeder as a model active pharmaceutical ingredient (API). The mass, mass flow and sizes of the particles were successfully monitored in real-time by the develop...
Chapter
The Internet of Things (IoT) is the network of physical objects embedded with electronics, software, sensors, and network connectivity, which enables these objects to collect and exchange data. The chapter introduces the Model-driven Multi-Domain IoT concept and provides a method and a supporting framework. Multi-Domain IoT as the actual frontier f...
Article
Full-text available
In software development, domain-specific languages (DSLs) are often applied for specific or repetitive tasks. For executable DSLs, a model interpreter can be developed to run DSL programs. Nevertheless, it is more widespread to generate code in a general-purpose programming language. A properly chosen DSL expresses the original problem more natural...
Conference Paper
Full-text available
Industry 4.0 with Internet of Things (IoT) is the next wave in technology revolution, which is expected to change our everyday life. This digitalization is having great impact on all the domains (energy, healthcare, transportation, manufacturing etc.) in addition to the Information and Communication Technologies (ICT) sector. In IoT scenarios, nume...
Conference Paper
Full-text available
Internet of things (IoT) becomes a prominent technology in our world. It is enabling the connection between the objects (the “things”) and the backend systems via the Internet. Everyday objects can become connected and smart. It has been adopted in different areas and applications such as smart cities, smart agriculture, smart healthcare, smart man...
Article
Vehicles are not just a means of transportation anymore, but they are also moving entities that collect and transmit a great amount of data, captured by sensors from the internals of the vehicle and from its environment as well. These data extended with smartphone sensors can be a stable base for smart car-based infocommunication systems. There are...
Article
Obfuscation is a technology that secures software artifacts from reverse engineering by making its cost prohibitively high. Intermediate level obfuscator implements the defensive mechanisms inside the software, and owing to high potency and resilience, can successfully secure the sensitive software components. This paper provides an analysis and pa...
Article
Full-text available
In recent years, the MapReduce framework has become one of the most popular parallel computing platforms for processing big data. MapReduce is used by companies such as Facebook, IBM, and Google to process or analyze massive data sets. Since the approach is frequently used for industrial solutions, the algorithms based on the MapReduce framework ga...
Chapter
The Internet of Things (IoT) is the network of physical objects embedded with electronics, software, sensors, and network connectivity, which enables these objects to collect and exchange data. The chapter introduces the Model-driven Multi-Domain IoT concept and provides a method and a supporting framework. Multi-Domain IoT as the actual frontier f...
Article
Full-text available
In this paper we present our VehicleICT platform, which we use for comparing the OBD-II and CAN bus data from vehicles. VehicleICT platform is based on the SensorHUB framework. We present a novel measurement tool called ObdCanCompare that collects vehicle sensor data and shows them on our smartphone. Meanwhile the data gets aggregated, processed an...
Article
A jármûvek jelenleg már nemcsak közlekedési vagy szállítási funkciókat szolgálnak. Ugyanolyan szenzorrendszerek, adatgyûjtô egységek, mint például az okostelefonok. Megfelelô eszközökkel és okostelefonunkkal kinyerhetjük ezen adatokat, és bekapcsolhatjuk jármûvünket az Internet of Things (IoT) világába. A SensorHUB keretrendszert felhasználva, a ki...
Article
Multimodal human–computer interaction refers to the interaction with the virtual and physical environment through natural modes of communication. Multimodal input user interfaces have significant role in different domains, for example industrial plants or hospitals, also they have implications for accessibility. To develop multimodal applications i...
Article
Full-text available
The Internet of Things (IoT) is transforming the surrounding everyday physical objects into an ecosystem of information that enriches our everyday life. The IoT represents the convergence of advances in miniaturization, wireless connectivity, and increased data storage and is driven by various sensors. Sensors detect and measure changes in position...
Article
A rule-based system is a series of if-then statements that utilizes a set of assertions, to which rules are created on how to act upon those assertions. Rule-based systems often construct the basis of software artifacts which can provide answers to problems in place of human experts. Such systems are also referred as expert systems. Rule-based solu...
Article
Software development requires adequate methods for requirements engineering, design, development, testing and maintenance. The more complex the system is, the more sophisticated methods should be applied. A significant part of software projects is short on appropriate requirements engineering, communication, development and testing method, furtherm...
Conference Paper
Full-text available
Vehicles are not just a means of transportation anymore, but they are also moving entities that collect and transmit a great amount of local data, captured by sensors from the internals of the vehicle and from its environment as well. The consumers of this information include the passengers, especially the driver, and the environment, i.e. other ve...
Article
Why is it important to verify/validate model transformations? The motivation is to improve the quality of the transformations, and therefore the quality of the generated software artifacts. Verified/validated model transformations make it possible to ensure certain properties of the generated software artifacts. In this way, verification/validation...
Article
Application of mobile and cyber-physical systems play an important role in cognitive infocommunications, especially in the Socio-Cognitive ICT area, because they are able to facilitate the requested information to users quickly. The Android platform is a good foundation for such systems since it runs on a wide variety of devices and provides some a...
Article
Obfuscation is a technology that secures software from unauthorized analysis and modification by making the cost of reverse engineering prohibitively high. Whereas there exist standard measurements for source-code and machine-code obfuscators, there is no standard approach to evaluate the quality of platform-independent obfuscator. This paper aims...
Article
Finding patterns in graphs is a fundamental problem in graph theory, and also a practical challenge during the analysis of big data sets. Inexact patterns may correspond to a set of possible exact graphs. Their use is important in many fields where pattern matching is applied (e.g. mining in social networks or criminal investigations). Based on pre...
Article
In modern software engineering environments, tools that use Domain-Specific Languages (DSLs) are often applied. The usual workflow of such tools is that the textual input written in the DSL is parsed and a semantic model is instantiated. This model is later passed to another software component that processes it, e.g. a model transformation, a code...
Article
Full-text available
Mobile devices and mobile applications have a significant effect on the present and on the future of the software industry. The diversity of mobile platforms necessitates the development of the same mobile application for all major mobile platforms, which requires considerable development effort. Mobile application developers are multiplatform deve...
Article
The essence of obfuscation is to entangle the code and eliminate the majority of logical links in it; that is, to transform the code so that it becomes complex enough for analysis and unauthorized modification. The developed theoretical apparatus allows us to describe an entangled program using concatenation of operational logics of the routines. C...
Article
Processing the textual scripts of computer languages is an important field in software development, which has been growing in popularity, recently. It is applied both for general-purpose programming languages and for domain-specific languages. There is a wide range of typical algorithms and patterns that are used to syntactically parse formal langu...
Article
Model-to-text transformations are often used to produce source code, documentation or other textual artefacts from models. A common way of implementing them is using template languages. Templates are easy to read and write, however, they tend to become long and complex as the complexity of the metamodel grows. This paper proposes a design pattern t...
Article
Full-text available
Energy-efficiency is a critical attribute of mobile applications, but it is often difficult for the developers to optimize the energy consumption on the code level. In this work we explore how we could use a model and code library based approach to assist the developer. Our vision is that developers can specify the operation on a high level and the...
Article
The essence of obfuscation is to entangle the code and eliminate the majority of logical links in it. The offered theoretical apparatus allows describing obfuscated routines by concatenation of original and fake operational logics. This approach considers not only instructions or routines themselves, but the actions (results) they produce, what mak...
Conference Paper
Translation of machine code to intermediate representation is an essential part of a platform-independent obfuscator that deals with intermediate code. The paper discusses a method of assembly code analysis and its translation to three-address code. The focus is set on basic block splitting, alias analysis, value-sets analysis, and interprocedural...
Conference Paper
In recent years the MapReduce framework has become one of the most popular parallel computing platform for processing big data. It is frequently used by companies such as Facebook, IBM, and Google. Moreover, more and more universities adopt this approach for their academic purposes. Since the MapReduce computing framework is designed for distribute...
Article
Model processing programs are regularly used when working with models or synthetizing the code from them; therefore, their verification has become an essential component of constructing reliable software in model-based software engineering. Models are usually formalized and visualized as graphs; therefore, model processing programs based on algebra...
Conference Paper
Embedded systems are usually modeled to simulate their behavior. Nowadays, this modeling is often implemented in the Simulink environment, which offers strong support for modeling complex systems. Moreover, via modeling, various analyses can be applied to the systems at design time. An important analysis is of the data types assigned to signal vari...
Conference Paper
The aim of obfuscation in general is to prevent malicious users from disclosing properties of the original source program. This goal can be achieved by an intermediate level obfuscation that deals with a target platform independent intermediate code. In this paper, we discuss general approaches to an intermediate level obfuscation algorithm, pointi...
Conference Paper
XML is a frequently applied data representation format to support the communication between software systems even if they are on different platforms. The process of transforming an in-memory object instance into bytes of an XML document is called XML serialization, the opposite direction is XML deserialization. Both processes introduce some cost th...
Conference Paper
Graph rewriting-based model transformation is an essential tool with a strong mathematical background used to process graph-based models. The most recent modeling tools tend to support the definition of rewriting rule based transformations in a visual or textual way. However, only a few of these support the continuous animation of the modifications...
Conference Paper
People use their mobile devices every day to access a wide variety digital content. The diversity of mobile platforms and that of mobile device capabilities requires providing automatic layout solutions for online content. For the purposes of this paper, our solutions focus on online magazines and newspapers. The Content-Driven Template-Based Layou...
Conference Paper
Recently embedded systems are often modeled using Simulink® to simulate their behavior. In order to perform the simulation, the modeling tool has to process the model. An important processing step is to determine the execution order of the elements in a model. This execution order is based on a sorted list of all semantically relevant model element...
Conference Paper
This paper discusses the adaptation and height definition methods for content-driven template based layout system. The overall goal of the approach is to provide a clear, consistent and user friendly layout language for magazine editors. This language facilitates to define magazine layouts and, based on these definitions, the related layout algorit...
Conference Paper
Embedded systems are often modeled using Matlab Simulink to simulate their behavior. These systems contain several different models. During the execution of these systems, the Simulink must provide some transformations for its models. One of the most common transformations is the flattening of the virtual subsystems within these models. If we execu...
Article
People use their mobile devices every day to access a wide variety digital content. The diversity of mobile platforms and that of mobile device capabilities requires providing automatic layout solutions for online content. For the purposes of this paper, our solutions focus on online magazines and newspapers. The Content-Driven Template-Based Layou...
Article
Recently, model transformation approaches are becoming increasingly popular; therefore their efficiency and usability are key factors and require further investigation. These approaches are regularly used in software engineering, most often as part of the model-driven development methodology. In the case of the graph rewriting-based model transform...
Article
Full-text available
Graph transformation has been widely used for expressing model transformations. Especially transformations of visual models can be naturally formulated by graph transformations, since graphs are well suited to describe the underlying structures of models. Based on a com-mon sample model transformation, four different model transformation approaches...
Article
Model-based development methods are increasingly being applied in the production of software artifacts. The processing of visual models, within these frameworks, is an essential issue that can be addressed using graph rewriting techniques. The precise definition of graph rewriting-based model transformation requires that beyond the topology of the...
Article
Embedded systems are usually modeled to simulate their behavior and facilitate design space exploration. Nowadays, this modeling is often implemented in the Simulink® environment, which offers strong support for modeling complex systems. As design progresses, models are increasingly elaborated by gradually adding implementation detail. An important...
Conference Paper
Mobile devices are elemental part of our daily life, we use them to reach and consume digital data. A reasonable part of online documents have a fixed layout, like Adobe's Portable Document Format (PDF). This inflexibility leads to a poor online reading experience, since the size and resolution of monitors and mobile devices require readers to scro...
Conference Paper
Full-text available
There is a need to provide university courses and education materials focusing on the current, new generation of software design and development methodologies. These methodologies include both high-level modeling and automated, model-based software synthesis. In 2008, we created a new university course focused on Model-Driven Development. Based on...
Conference Paper
Nowadays model transformation is used frequently in software development. Therefore, its effectiveness and usability have a big influence on the whole development phase. The attributes of the model transformation are mainly determined by the applied model transformation language. The goal is to develop an expressive, versatile but still effectively...
Conference Paper
Most Graphical User Interface (GUI) frameworks offer layout managers that are commonly based on tabular arrangement. We introduce few wide-spread layout approaches and discuss their specialties. Furthermore, we investigate the state of the art research results on the field of automatic GUI layout. Based on the lessons learned from the existing layo...
Article
This paper considers process of obfuscation as adding additional (redundant) entities to the program at intermediate representation that would complicate the understanding of entangled code. The presented mathematical apparatus discusses introductory terms, definitions, and operations and formulates a theorem about NP-completeness of such deobfusca...
Conference Paper
With the increasing application of the Model-Driven Development, the model transformation approaches and tools have become an emerging researching field. An important aspect of model-driven approaches is the language that facilitates the definition of model transformations. In case of model transformation languages it is essential to investigate ho...
Article
Following the trend of other editions, it was held this year (2011) in Wellington, New Zealand, the 5th International Workshop on Multi-Paradigm Modelling: Concepts and Tools (MPM). Once again has been a satellite event of the International Conference on Model-Driven Engineering Languages and Systems (MoDELS). It aims at further the state-of-the-ar...
Conference Paper
Full-text available
Large systems providing end-user services require a robust and manageable component-based implementation. Examples of such systems are web-based and other distributed systems with many users, public utilities (such as electricity and gas supply), or the core infrastructure that powers the digital convergence in the Information Society. Their implem...
Conference Paper
Software Product Lines enable the development of a domain-specific set of similar systems. They rely on the predictable reuse of assets and components. Systems following this approach inherently support mass customization and configuration during the entire evolution of the product family. Feature modeling, in conjunction with Software Product Line...
Article
Software quality is always the target of disagreement between developers and users because of its subjective nature. The problem with software quality is the lack of formal definitions. Furthermore, quality metrics are based on empirical indices. This paper presents a method to the application of formal modeling techniques in the subject of softwar...
Article
Usually, verification of graph rewriting-based model transformations is performed manually, however, the industrial applications require automated methods. In several cases, transformation developers are interested in the offline analysis, when only the definition of the transformation and the specification of the modeling languages are taken into...
Article
Verification of model processing programs, where only the definitions of the program and the languages of the models to be transformed are analyzed, has become a fundamental issue in model-based software engineering. This analysis may become very complex, but it is performed only once and the results are independent from concrete input models. The...
Conference Paper
The offline analysis of graph rewriting-based model transformations, when only the definition of the transformation and the specification of the modeling languages are taken into account, have gained focus recently. In this case, the analysis must be performed only once, and the results are independent from the concrete input models. For the formal...
Conference Paper
Full-text available
Multi-Paradigm Modelling (MPM) is a research field focused on solving the challenge of combining, coupling, and integrating rigorous models of some reality, at different levels of abstraction and views, using adequate modelling formalisms and semantic domains, with the goal to simulate (for optimization) or realize systems that may be physical, sof...
Article
Model-based software engineering is an increasingly applied method in producing software artifacts that is driven by model transformation. For example, Model-Driven Architecture (MDA) is an approach to develop software based on different models. Source code is generated automatically from these models. This makes model transformations the heart of...
Article
The Multi-Paradigm Modeling (MPM) approach of model-based development emphasizes the specification of a system by multiple models. We use transformations to automatically transform, integrate and synchronize models. Verification and validation of model transformations are fundamental issues: we need to express what a valid model is and how a valid...
Conference Paper
Full-text available
Verification of models and model processing programs are inevitable in real world model-based software development. Model transformation developers are often interested in offline verification methods, when only the definition of the model transformation and the specification of the source and target languages are used to analyze the properties and...
Article
Verification of model processing programs, where only the definitions of the program and the languages of the models to be transformed are analyzed, has become a fundamental issue in model-based software engineering. This analysis may become very complex, but it is performed only once and the results are independent from concrete input models. The...
Conference Paper
Verification of models and model processing programs are inevitable in real-world model-based software development. Model transformation developers are interested in offline verification methods, when only the definition of the model transformation and the metamodels of the source and target languages are used to analyze the properties and no concr...
Conference Paper
As the support is increasing for textual domain-specific languages (DSL), the reconstruction of visual models from the generated textual artifacts has also come into focus. The state-of-the-art bidirectional approaches support reversible text generation from models using single syntax mapping. However, even these tools have not gone such far to fac...
Conference Paper
Offline verification of model processing programs has become a fundamental issue in model-based software development. Offline means that only the definitions of the program and the concerned modeling languages are taken into account. Therefore, the results of the analysis hold for every possible input model. Although the offline analysis is very co...
Article
Model-Driven Development (MDD) facilitates the synthesis of application programs from models using customized, domain-specific model processors. MDD appears in many, different areas including telecommunication services, communication protocols, enterprise networking and multimedia systems. Model compilers can be realized by graph rewriting-based mo...
Article
Verification of models and model processing programs are inevitable in model-based software development in order to apply them in real-world solutions. Verification of properties of model transformations means to prove that the application of a model transformation generates the expected output models from the input models. Model transformation dev...
Conference Paper
Full-text available
Model-Based Design of complex software systems is an activity that requires the use of different modeling formalisms, with different perspectives of the system, to cover all relevant aspects of the system, to avoid over-design, to employ manageable models and to support system integration. The comprehensive use of models in design has created a set...
Article
Model transformation is a crucial aspect of Model-Driven Software Development. With the help of model transformation, we can generate source code or other artifacts from software models. However, a recurring problem in software development is the fact that source and target models coexist and they evolve independently. In general, a modeled system...
Conference Paper
Full-text available
Model synchronization is an extant and significant problem in model-related technologies. In general, a modeled system is composed of several models that are often related to one another. Consequently, if one model is altered in the development process, the related models will not be consistent anymore. For that reason, resolving inconsistency betw...
Article
Metamodeling is a widely applied technique in the field of graphical languages to create highly configurable modeling environments. These environments support the rapid development of domain-specific modeling languages (DSMLs). Design patterns are efficient solutions for recurring problems. With the proliferation of DSMLs, there is a need for domai...
Conference Paper
This Model-Driven Development (MDD) facilitates the synthesis of application programs from models created using customized, domain-specific model processors. Model compilers can be realized by graph rewriting-based model transformation. In Visual Modeling and Transformation System (VMTS), metamodel-based rewriting rules facilitate to assign OCL con...
Conference Paper
Model-driven approaches try to improve the productivity of the traditional software development by focusing on a special problem using high abstraction models. Comparing to the source code, specific visualization of models inspired by these domains is very advantageous and closer to the human thinking. Though, in many cases the details can be effic...
Conference Paper
Model transformation is a crucial aspect of model-driven software development. With the help of model transformation, we can generate source code or other models from software models. However, a recurring problem in software development is the fact that source and target models coexist and they evolve independently. This means that after the initia...
Article
Full-text available
Verification of the transformations is a fundamental issue for applying them in real world solutions. We have previously proposed a formalization to declaratively describe model transformations and proposed an approach for the verification. Our approach consists of a reasoning system that works on the formal transformation description and deduction...
Article
Full-text available
Verification of models and model processing programs are fundamental issues and are inevitable in model-based software development in order to apply them in real-world solutions. Verification concerns the analysis of non-functional and functional properties as well. Model transformation developers are interested in offline methods for the verificat...
Conference Paper
This paper presents the design, architecture, and implementation experiences related to building a multipurpose modeling and model transformation frameworks. We examine the usual expectations related to model-driven development tools, then we present the architecture and design decisions of a new modeling framework capable of fulfilling all these e...
Conference Paper
Model transformation is a focused area in model-driven software development. With the help of model transformations we can generate source code, other models and documentation from the source models. During the development, a recurring problem is that the source and target artifacts coexist and they evolve independently. This means that after the t...
Article
Metamodeling techniques have become the subject of research in the last decades. Different approaches of software development emphasize the use of models at all phases of the design and implementation. With metamodels, we can define the concepts of models in concrete domains. Model transformations are used to convert models to other ones. To define...
Conference Paper
Developing software for mobile devices requires special attention, and it is still a larger effort compared to the development for desktop computers and servers. With the introduction and the popularity of wireless devices, the diversity of the platforms has also been increased. There are different platforms and tools from different vendors such as...
Conference Paper
The introduction of UML class diagrams has not raised the abstraction level of development to the extent that was intended: class diagrams are only the visual representations of source class skeletons implemented in a programming language. To improve the productivity, domain-specific languages are applied, which cover a narrow domain, and their hig...
Article
Model-driven Software Engineering is one of the most focused research fields. Model processors automatically generate the lower level artefacts. Graph transformation is a widely used technique for model transformations. Especially visual model transformations can be expressed by graph transformations. This paper presents a visual control flow suppo...
Article
The orientation of the current software development practice requires efficient model-based iterative solutions. The high costs of maintenance and evolution during the life cycle of the software can be reduced by using tool-aided iterative development. This paper presents how model-based iterative software development can be supported through effic...
Article
Teamwork is the typical characteristic of software development, because the taskscan be splitted and parallelized. The independently working developers use SoftwareConfiguration Management (SCM) systems to apply version control to their files and tokeep them consistent. Several SCM systems allow working on the same files concurrently,and attempt to...
Conference Paper
Model-based approaches in development are widely recognized as a potential way of increasing productivity in software engineering. Model-based development is driven by model transformations that attempt to bridge the large semantic gaps between high-level models and low-level languages. There is a demand for researching the ways in which model tran...
Article
The orientation of the current software development practice requires efficient model-based iterative solutions. The high costs of maintenance and evolution during the life cycle of the software can be reduced by using tool-aided iterative development. This paper presents how model-based iterative software development can be supported through effic...