229 research outputs found
Model Based System Engineering for the development of System on Chip
Abstract. Model Based System Engineering (MBSE) has been utilized in auto manufacturing industries, airplane manufacturing and maintenance, and factory process automation industries. These are some of the complex fields. As SoC design is a complex process and requires years of work, MBSE can reduce time, complexity, reuse, and maintenance costs. It seems a fruitful idea/decision to take MBSE into use in SoC design depending on the previously mentioned elements. System on Chip (SoC) is obtaining the interest of many big companies. Therefore, MBSE will represent a huge competitive advantage once it is taken fully into the systems engineering roles of SoC. The existence of geographically dispersed teams, complexity of systems, interdisciplinarity, personalized system description, and their integration can be enabled by MBSE. As an emerging paradigm for the systems of the 21st century, MBSE paved the way for creating successful systems (for the companies) that are end to end connected. This research focuses on making use of MBSE in SoC. The thesis will show how SoC processes can be implemented in one complete model with top to bottom approach. Firstly, the traditional systems engineering approach has been explained with its tools and examples. Secondly, the need for taking up MBSE by the systems engineers is expressed. This contains the applications, use in modern systems, and benefits of MBSE. Moreover, MBSE methodology tools, languages, and their use in SoC is illustrated with examples. As SoC development is a huge and complex process; therefore, a small component of the chip has been taken in consideration for the purpose of understanding and making of the thesis. MBSE is a model-based approach hence a language needs to be present to produce these models and that language is SysML and OPD/OPL. SysML language and MagicDraw tool is used for expressing the architecture of the system. MagicDraw supports several external evaluators for evaluation of expressions and MATLAB is one of them. With MagicDraw we can do simulations, input parameters, and analyze data by processing on it using algorithms developed in MATLAB
Caching, crashing & concurrency - verification under adverse conditions
The formal development of large-scale software systems is a complex and time-consuming effort. Generally, its main goal is to prove the functional correctness of the resulting system. This goal becomes significantly harder to reach when the verification must be performed under adverse conditions. When aiming for a realistic system, the implementation must be compatible with the “real world”: it must work with existing system interfaces, cope with uncontrollable events such as power cuts, and offer competitive performance by using mechanisms like caching or concurrency.
The Flashix project is an example of such a development, in which a fully verified file system for flash memory has been developed. The project is a long-term team effort and resulted in a sequential, functionally correct and crash-safe implementation after its first project phase. This thesis continues the work by performing modular extensions to the file system with performance-oriented mechanisms that mainly involve caching and concurrency, always considering crash-safety.
As a first contribution, this thesis presents a modular verification methodology for destructive heap algorithms. The approach simplifies the verification by separating reasoning about specifics of heap implementations, like pointer aliasing, from the reasoning about conceptual correctness arguments.
The second contribution of this thesis is a novel correctness criterion for crash-safe, cached, and concurrent file systems. A natural criterion for crash-safety is defined in terms of system histories, matching the behavior of fine-grained caches using complex synchronization mechanisms that reorder operations.
The third contribution comprises methods for verifying functional correctness and crash-safety of caching mechanisms and concurrency in file systems. A reference implementation for crash-safe caches of high-level data structures is given, and a strategy for proving crash-safety is demonstrated and applied. A compatible concurrent implementation of the top layer of file systems is presented, using a mechanism for the efficient management of fine-grained file locking, and a concurrent version of garbage collection is realized. Both concurrency extensions are proven to be correct by applying atomicity refinement, a methodology for proving linearizability.
Finally, this thesis contributes a new iteration of executable code for the Flashix file system. With the efficiency extensions introduced with this thesis, Flashix covers all performance-oriented concepts of realistic file system implementations and achieves competitiveness with state-of-the-art flash file systems
Experimentation to Evaluate the Benefits of Model Driven Development
Tesis por compendio[ES] El Desarrollo Dirigido por Modelos, MDD por sus siglas en inglés (Model Driven Development), es un enfoque de ingeniería del software que centra la creación y evolución de productos software en el modelado. Desde hace casi dos décadas, la comunidad científica ha descrito muchas de las ventajas de MDD frente a otros enfoques, sin embargo, su adopción en el entorno industrial es muy poco frecuente.
Con el objetivo de entender por qué MDD no ha reemplazado otros enfoques de ingeniería software, he realizado una investigación empírica a través de tres experimentos controlados. Con el primer experimento pretendo aclarar si los beneficios de MDD frente al Desarrollo centrado en Código, CcD por sus siglas en inglés (Code Centric Development), son fieles a la realidad del desarrollo software actual. En el segundo experimento comparo la valoración que realizan los ingenieros de los modelos que utilizan, con su utilidad para ser utilizados en contextos MDD. En el tercer experimento analizo el desempeño de los profesionales software en tareas de mantenimiento en contextos MDD.
Nuestros resultados confirman los beneficios de MDD frente a otros enfoques, pero también, que la intención de uso de MDD no alcanza valores máximos. Los sujetos subestiman el potencial de los modelos que desarrollan y utilizan en contextos MDD. El problema de adopción parece estar ligado a factores humanos, no a factores técnicos.[CA] El Desenvolupament Dirigit per Models, MDD (Model Driven Development), és un enfocament d'enginyeria del programari que centra la creació i evolució de productes programari en el modelatge. Des de fa quasi dues dècades, la comunitat científica ha descrit moltes dels avantatges de MDD enfront d'altres enfocaments, no obstant això, la seua adopció en l'entorn industrial és molt poc freqüent.
Amb l'objectiu d'entendre per què MDD no ha reemplaçat altres enfocaments d'enginyeria programari, he realitzat una investigació empírica a través de tres experiments controlats. Amb el primer experiment pretenc aclarir si els beneficis de MDD enfront d'altres enfocaments, com el Desenvolupament centrat en Codi, CcD (Code Centric Development), són fidels a la realitat del desenvolupament programari actual. En el segon experiment compare la valoració que realitzen els enginyers dels models que utilitzen, amb la seua utilitat per a ser utilitzats en contextos MDD. En el tercer experiment analitze l'acompliment del professional programari en tasques de manteniment en contextos MDD.
Els nostres resultats confirmen els beneficis de MDD enfront d'altres enfocaments, però també, que la intenció d'ús de MDD no aconsegueix valors màxims. Els subjectes subestimen el potencial dels models que desenvolupen i utilitzen en contextos MDD. El problema d'adopció sembla estar lligat a factors humans, no a factors tècnics.[EN] Model Driven Development (MDD) is a software engineering approach in which the code of a software product is generated and evolutionated from conceptual models that abstractly represents the system. For nearly two decades, the scientific community has described many of the advantages of MDD over other approaches. Despite the benefits of MDD, its use in real practical developments is merely anecdotal.
To understand why MDD has not replaced other software engineering approaches, I have conducted an empirical investigation through three controlled experiments. The first experiment aims to clarify whether the benefits of MDD compared to code-centric development (CcD) match the reality of development in real environments. In the second experiment, I compare engineers' assessment of the models they develop with the usefulness of these models to be used in MDD contexts. In the third experiment, I analyze the performance of software professionals in maintenance tasks in MDD contexts.
Our results confirm the benefits of MDD over other approaches; however, the intention to use MDD does not reach maximum values. Subjects underestimate the potential of the models they develop and use in MDD contexts. The adoption problem seems to be linked to human factors, not to technical factors.Domingo Montes, MÁ. (2022). Experimentation to Evaluate the Benefits of Model Driven Development [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/185748Compendi
European Privacy by Design [védés előtt]
Three competing forces are shaping the concept of European Privacy by Design (PbD): laws and regulations, business goals and architecture designs. These forces carry their own influence in terms of ethics, economics, and technology.
In this research we undertook the journey to understand the concept of European PbD. We examined its nature, application, and enforcement. We concluded that the European PbD is under-researched in two aspects: at organizational level (compared to the individual level); and mainly in the way it is enforced by authorities. We had high hopes especially with regards to the latter, and eager to bring significant scientific contribution on this field. We were interested to learn if data protection authorities are having such impacts looking at European PbD, that can pioneer new approaches to privacy preservation. This is why we elaborated on possible ways to measure their activity, in a manner that both legal and non-legal experts can understand our work.
We promised a response to the research question can the enforcement of European PbD be measured and if yes, what are possible ways to do so? We conducted data analytics on quantitative and qualitative data to answer this question the best way possible. Our response is a moderate yes, the enforcement of PbD can be measured. Although, at this point, we need to settle with only good-enough ways of measure and not dwell into choosing the most optimal or best ways.
One reason for this is that enforcement of PbD cases are highly customized and specific to their own circumstances. We have shown this while creating models to predict the amount of administrative fines for infringement of GDPR. Clustering these cases was a daunting task.
Second reason for not delivering what could be the best way of measure is lack of data availability in Europe. This problem has its roots in the philosophical stance that the European legislator is taking on the topic of data collection within the EU. Lawmakers in Europe certainly dislike programs that collect gigantic amounts of personal data from EU citizens.
Third reason is a causal link between the inconsistent approach between the data protection authorities’ practices. This is due to the different levels of competencies, reporting structures, personnel numbers, and experience in the work of data protection authorities.
Looking beyond the above limitations, there are certainly ways to measure the enforcement of European PbD. Our measurements helped us formulate the following statements:
a. The European PbD operates in ‘data saver’ mode: we argue that analogous to the data saving mode on mobile phones, where most applications and services get background data only via Wi-Fi connection, in Europe data collection and data processing is kept to minimal. Therefore, we argue that European PbD is in essence about data minimization. Our conviction that this concept is more oriented towards data security have been partially refuted.
b. The European PbD is platform independent: we elaborated in the thesis on various infrastructures and convergent technologies that found compatibility with the PbD principles. We consider that the indeed the concept is evolutionary and technology –neutral.
c. The European PbD is a tool obligation: we argue that the authorities are looking at PbD as a tool utilization obligation. In a simple language, companies should first perform a privacy impact assessment in order to find out which tools are supporting their data processing activities and then implement these, as mandated PbD.
d. The European PbD is highly territorial: we reached the conclusion that enforcement of PbD is highly dependent on geographical indicators (i.e. countries and counties). The different level of privacy protection cultures are still present in Europe. On a particular level, what is commonly true across all countries is that European PbD mandates strong EU data sovereignty
Strategic frameworks for managing lean construction on megaprojects; towards global integrated delivery and corporate governance
Built environment encounters substantial risk and challenges in its evolution towards
sustainable development. International businesses and multinational engineering
organisations face global connectivity challenges between business units, especially
during the outbreak of novel coronavirus pandemic (COVID-19), which has
profoundly disrupted the construction industry throughout the world. That raises the
need to manage global connectivity as a main strategic goal of multinational
organisations. Therefore, the research aim is to develop strategic frameworks for
managing risk, challenges, and integration of lean construction (LC) and integrated
project delivery (IPD) on construction megaprojects (CMPs) towards the global
integrated delivery (GID) transformative initiatives and corporate governance in
multinational organisations. The scope of the study mainly focuses on CMPs and
multinational architecture, engineering and construction (AEC) organisations.
The following research objectives (ROs) was set out in fulfilling the study’s aim: (1)
To appraise influence of partnering agreements associated with BIM adoption on
stakeholder’s behaviour. (2) To critically assess critical success factors (CSFs) for
adoption BIM and LC practices. (3) To critically assess barriers to integrating BIM
and LC practices. (4) To critically analyse and develop frameworks for the
interactions between BIM and LC. (5) To critically appraise barriers to integrating LC
and IPD towards the GID global initiatives. (6) To develop a competency framework
that integrate LC and IPD, and critically appraise key drivers (KDs) to integrating LC
and IPD towards FOW global initiatives. (7) To develop frameworks for managing
risk and challenges of integrating LC and IPD towards the GID transformative
initiatives and corporate governance.
Research objectives were achieved via adoption of ‘mixed research methods’ involving a two-stage quantitative and qualitative research approach. This included
the adoption of an in-depth review of extant literature, pilot studies, Delphi surveys,
questionnaires surveys, semi-structured interviews and focus group techniques, and
the use of several statistical analysis tools such as descriptive and inferential statistics
and structural equation modelling (SEM). The qualitative research methodology
consists of a literature review to assess challenges to integrate LeanIPD&GID on
CMPs. In addition, there is an assessment of conceptualisation of LeanIPD&GID and
GID strategy placements, development of LeanIPD&GID integration framework, and
future of work (FOW) global initiatives with multiple validations. The thesis is
presented in manuscript format. The analysis involved semi-structured interviews and
focus group techniques. Stage two consisted of questionnaire survey that shaped the
foundation of analysis and findings of 190 respondents from 23 countries with an
extensive cosmopolitan experience of megaprojects in construction. The survey
examined a set of 20 challenges to integrate LeanIPD&GID on CMPs resulting from a
detailed analysis of extant literature after validation. Descriptive and inferential
statistical tests were exploited for data analysis and percentage score analysis.
The research findings involved conceptualisation of LeanIPD&GID principles,
proposed GID strategy placements, frameworks for managing challenges of
LeanIPD&GID transformative initiatives and corporate governance, FOW global
initiatives and key performance indicators (KPIs). It concluded that the most
significant challenges to integrate of LeanIPD&GID on CMPs are ‘lack of
governmental incentives, policies, regulations or legal frameworks,’ ‘lack of client’s
awareness and IPD experience amongst key stakeholders,’ ‘lack of organisation’s
senior-management and client’s commitment to IPD approaches,’ ‘resistance of
industry to change from traditional procurement to IPD,’ and ‘lack of integrated synergies between LC, IPD working towards LeanIPD&GID.’ Awareness of building
BIM in the MENA region is higher than LC, and LC awareness is higher than IPD
knowledge. While BIM adoption in the MENA region is higher than LC, LC is still
taking its first steps, and IPD has little implementation. LeanBIM is slightly
integrated, while LeanIPD integration is almost not present.
The research findings, conclusions and recommendations provide proposed
frameworks for implementation, KPIs, and GID strategy placements for
LeanIPD&GID transformative initiatives and corporate governance to integrate
LeanIPD&GID on CMPs and FOW global initiatives. This will allow project key
stakeholders to place emphasis on managing LeanIPD&GID challenges identified in
this research and commence GID strategies. The study has provided effective
practical strategies for enhancing integration of LeanIPD&GID transformative
initiatives on CMPs and corporate governance
Hard-Real-Time Computing Performance in a Cloud Environment
The United States Department of Defense (DoD) is rapidly working with DoD Services to move from multi-year (e.g., 7-10) traditional acquisition programs to a commercial industrybased approach for software development. While commercial technologies and approaches provide an opportunity for rapid fielding of mission capabilities to pace threats, the suitability of commercial technologies to meet hard-real-time requirements within a surface combat system is unclear. This research establishes technical data to validate the effectiveness and suitability of current commercial technologies to meet the hard-real-time demands of a DoD combat management system. (Moreland Jr., 2013) conducted similar research; however, microservices, containers, and container orchestration technologies were not on the DoD radar at the time. Updated knowledge in this area will inform future DoD roadmaps and investments. A mission-based approach using Mission Engineering will be used to set the context for applied research. A hypothetical yet operationally relevant Strait Transit scenario has been established to provide context for definition of experimental parameters to be set while assessing the hypothesis. System models federated to form a system-of-systems architecture and data from a cloud computing environment are used to collect data for quantitative analysis
APPLICATIONS OF GRAPH THEORY FOR REUSE OF MODEL BASED SYSTEMS ENGINEERING DESIGN DATA
This dissertation contributes to systems engineering (SE) by introducing and demonstrating a novel graph-based design repository (GBDR) tool. GBDR enables engineers to leverage system design information from a heterogenous set of system models created using multiple model based systems engineering (MBSE) software tools as an integrated body of knowledge. Specifically, the research provides a set of approaches that allow the use of system models described in Systems Modeling Language and Lifecycle Modeling Language as an integrated body of design information. The coalesced body of system design information serves to support concept ideation and analysis within SE. The research accomplishes this by using a graph database to store system model information imported from digital artifacts created by MBSE tools and applying principles from graph theory and semantic web technologies to identify likely connections and equivalent concepts across system models, modeling languages, and metamodels. The research demonstrates that the presented tool can import, store, synthesize, search, display, distribute, and export information from multiple MBSE tools. As a practical demonstration, feasible subsystem design alternatives for a small unmanned aircraft system government reference architecture are identified from within a set of existing system models.OSD CAPECivilian, Office of the Secretary of DefenseApproved for public release. Distribution is unlimited
32. Forum Bauinformatik 2021
Das Forum Bauinformatik ist eine jährlich stattfindende Tagung und ein wichtiger Bestandteil der Bauinformatik im deutschsprachigen Raum. Insbesondere Nachwuchswissenschaftlerinnen und -wissenschaftlern bietet es die Möglichkeit, ihre Forschungsarbeiten zu präsentieren, Problemstellungen fachspezifisch zu diskutieren und sich über den neuesten Stand der Forschung zu informieren. Es bietet sich ausgezeichnete Gelegenheit, in die wissenschaftliche Gemeinschaft im Bereich der Bauinformatik einzusteigen und Kontakte mit anderen Forschenden zu knüpfen
Continuity of object tracking
2022 Spring.Includes bibliographical references.The demand for object tracking (OT) applications has been increasing for the past few decades in many areas of interest: security, surveillance, intelligence gathering, and reconnaissance. Lately, newly-defined requirements for unmanned vehicles have enhanced the interest in OT. Advancements in machine learning, data analytics, and deep learning have facilitated the recognition and tracking of objects of interest; however, continuous tracking is currently a problem of interest to many research projects. This dissertation presents a system implementing a means to continuously track an object and predict its trajectory based on its previous pathway, even when the object is partially or fully concealed for a period of time. The system is divided into two phases: The first phase exploits a single fixed camera system and the second phase is composed of a mesh of multiple fixed cameras. The first phase system is composed of six main subsystems: Image Processing, Detection Algorithm, Image Subtractor, Image Tracking, Tracking Predictor, and the Feedback Analyzer. The second phase of the system adds two main subsystems: Coordination Manager and Camera Controller Manager. Combined, these systems allow for reasonable object continuity in the face of object concealment
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