Computational Representation And Reasoning Support For Requirements Change Management In Complex System Design

Requirements play a critical role within any design process and the activity of identifying and maintaining a system\u27s requirements is essential to. However, design is a complex and iterative process, where requirements are continuously evolving and are volatile. This change, if not managed, may result in undesired uncertainty within the design process leading to monetary losses and time delays, as the changing of requirements has been recognized as a major cause of project failure. In order to mitigate issues that arise due to requirement change propagation, this research presents a computational reasoning tool to help designers and engineers predict change propagation in the requirements domain. The developed tool makes use of requirements syntactical elements to build relationships between requirements. Two heterogeneous industry case studies, spanning four engineering change propagations, are used to both explore the use of requirements in predicting change propagation and generalize an automated prediction tool. Using design structure matrices and graph theoretic based metrics a predictive model is generalized from 491,520 relationship and metric permutation combinations. The developed tool makes use of an RMS scoring algorithm to rank requirements in order of most likely to change due to previous requirement changes. The developed tool is tested against a third industry case study where five engineering changes are predicted. Results indicate the tool can predict sixty percent of change propagation within the top four percent requirements scoring and predict all change propagation within the top thirteen percent scoring

METHODS OF ADAPTIVE REUSE IN ALEXANDRIA’S BUILDINGS WITH HERITAGE VALUES

Due to the rapid progress in the digital technology, using 3D modelling and augmented reality in architecture, now we can transform, create qualitative and sustainable changes in the interior architecture of our architectural heritage, to achieve sustainable cities, this study of the interior architectural solutions developed between architectural heritage, digital registration processes, and parametric construction and fabrication systems. Also using of Information Systems in recording and documenting buildings and archaeological areas. It helps in designing through computer systems “Virtual Reality” to determine methods of conservation and dealing with archaeological areas and buildings. Using information networks to exchange information globally and locally on urban heritage and methods of preserving and dealing with it this progress in the digital technologies, minimize the construction, adaptive reuse and conservation costs. This study describes the different ways and benefits of using the digital technology, which can tailor materials, styles and functions into bespoke building components with a new notion of materiality, style and function in interior architectural transformation projects of buildings with heritage values. The study addresses the adaptive reuse of interior architecture of our architectural heritage through the latest digital technology methods in treatment of the architectural heritage while maintaining the relationship between the technical value of old and modern

A Study of Designer Familiarity with Product and User During Requirement Elicitation

It is important to recognise the effects of a designer\u27s source of information and decision making during requirements elicitation. Requirements are widely recognised as an important step in the design process. Designers may have perspective based on their experience which results in a level of familiarity with the design. This paper reports on a study that explores the effects of designer familiarity with a project and its user on their ability to elicit requirement specifications. Two familiarity constructs, product and user, are measured as low or high and used to study requirement elicitation with varying familiarity. A high familiarity study using five graduate students and a low familiarity study using a team of five students during senior capstone design are compared for their requirements elicitation. The results of this study include an analysis of the requirements developed and participant survey results from the elicitation process. The results revealed familiarity does in fact have an effect on the ability of elicit requirements. Participants in the low familiarity study expressed difficulty and eliciting requirements while those in the high familiarity study were able to generate more requirements at a faster rate

Development of a Sensible Reduced-Order Modeling Framework for Geomechanics Simulation: With Application to Coupled Flow and Geomechanics Simulation

With the recent development of unconventional reservoirs, attention has been geared towards the integration of the geomechanical models with traditional flow simulation. A case in point is quantifying rock-fluid interactions in hydraulic fracturing operations. Although much effort has gone into the creation and advancement of commercial simulation software for coupled flow and geomechanics, it is still in its infancy. The models are considerably oversimplified and poorly representative of the problem’s complex nature. Throughout history, several contributions have been made into the development of efficient model-order reduction (MOR) techniques for “flow only” simulations. Yet – to date – contributions to the mechanical models in coupled simulations have been minimal. This study tackles this challenging aspect, by proposing a novel model reduction adaptive workflow, especially for the mechanics simulators, that (1) can be coupled with any simulator that can export mass, stiffness, and load matrices; (2) can achieve 2 orders of magnitude in computational time reduction; and (3) do not add more complexity to the solution. In the first part of this research, several – widely used – reduction techniques for structural mechanics were implemented based on the construction of the dynamic condensation matrix. Single-step reduction methods were first executed; in particular, Guyan DOFs based reduction techniques. Following that, two-step methods were implemented; where corrections were made to the results obtained from the former. Finally, iterative (three-step) reduction methods were applied; handling the problem of master DOFs selection through consistent updates of the dynamic condensation matrix until convergence is achieved. To that end, two schemes are presented; based on the convergence of the dynamic condensation matrix, as well as, the eigenvalues of the reduced-order model. In the second part of this research, we provide a rigorous framework for testing the completeness, efficiency, and convergence for all the presented reduction techniques. Regarding the completeness of the reduced models, two main criteria were investigated; namely, modal assurance criterion (MAC) and singular value decomposition (SVD). For efficiency testing, percent error (PE) of natural frequencies and the correlation coefficient for modal vector (CCFMV) values were considered. Finally, the efficiency of the convergent criterion was demonstrated through the errors associated with the column vectors of the condensation matrix. Several numerical examples are presented to show the efficiency of the presented framework, particularly for coupled simulations. Based on the adopted framework, we managed to reduce the scale of the finite element models to less than 9% of the full model with error as low as 1%. In terms of computational speed and runtime, we achieved substantial speedups; up to 20X. Given the proposed workflow, large-scale complex simulations – similar to those associated with hydraulic fracturing – could be more feasible and less costly. This, ultimately, would give allowance for incorporating the complex physics pertinent to unconventional reservoirs and motivate the advent of their development at no additional cost

Reasons for Change Propagation: a case study in an automotive OEM

This paper focuses on identifying the reasons for change propagation during the production phase of the product life cycle. Unlike the traditional change propagation study where the focus is within the product, this study is focused to understand the propagation effects of change on other functional silos in the manufacturing firm. First, the reasons for the changes are identified using archival analysis through which it is found that 77.0 % of changes are due to internal reasons while 23.0 % are external. Second, these changes are distinguished into genesis, and propagated changes using a matrix-based modeling approach from which the reasons for propagation are identified. It is inferred that 32.4 % of the total changes are due to propagated changes such as inventory issues, manufacturing issues, and design error rectification. The majority of reasons for these propagated changes include document error rectification such as BOM error, drawing error, incorrect introduction date in engineering change note, and design error rectification such as design limitations. The findings indicate nearly one-third of time spent by the engineers can be reduced by developing appropriate controls during the change release process

Predicting Requirement Change Propagation Using Higher Order Design Structure Matrices: An Industry Case Study

This research examines higher order design structure matrices as requirements change modelling tools to predict requirement change propagation through two large-scale industry design projects. Due to the iterative nature of design, requirements will evolve and change. Changes in requirements can propagate to other requirements on different subsystems leading to possible increases in the project cost and lead-time. Predicting these requirement changes enables the designers to foresee unanticipated changes and maximises the probability for the project\u27s success. These studies reveal that second-order relationships are influential in predicting requirement change propagation. Unforeseen propagation occurring in first-order form was rare, rather it was occurring in second order. Modelling requirements change exposes these secondary relationships early in the engineering change (EC) definition process, thereby enhancing the decision-making process and augmenting cost estimation. A modelling tool, such as that proposed in this paper, can provide the designer insight into the requirements which may be affected before approving an EC

Chemistry and NMR studies of Beta-Catenin-TCF4 interaction

Abweichungen im Wnt/Beta-Catenin Signalweg kommen in vielen verschiedenen menschlichen Krebserkrankungen vor. Unter anderem wird dieser Signalweg in Darm- und Eierstockkrebs aktiviert. Aus diesem Grund haben Inhibitoren der TCF4/Beta-Catenin Interaktion großes Potential als Antitumormittel. Mit Hilfe des vor kurzem beschriebenen „Meta-Structure“ Ansatzes haben wir eine Reihe von niedermolekularen Molekülen identifiziert, die an Beta-Catenin binden und als Ausgnagspunkt für zukünftige Entwicklungen dienen könnten. Um diese Interaktionen zu testen, wurden verschiedene Methoden angewandt: 1D 1H-STD, 1D AFP NOESY, 2D NOESY und 19F-NMR. Auch die Fähigkeit der neu identifizierten Liganden mit dem bekannten Bindungspartner TCF4 von Beta-Catenin zu konkurrieren wurde getestet. Zur weiteren Untersuchung der Interaktionen und um weitere neue Liganden synthetisieren und identifizieren zu können, wurde ein sogenannter „Dynamic Combinatorial Library“ Ansatz (Dynamische, kombinierbare Chemikalienbibliothek) adaptiert und mithilfe . Weiters wurden zwei- und dreidimensionale NMR-Experimente durchgeführt, mit welchen die 1N-15H Signale des TCF4 Proteinrückgrats, und zweier separate Teile hiervon, bei pHs von 4,5 und 2,0 zugeordet werden konnten. Ein Vergleich der so bestimmten Frequenzen mit den errechneten Werten eines theoretischen, gänzlich unstrukturierten Proteins gleicher Aminosäuresequenz („Secondary Structure Propensity“) erlaubte es, Aussagen über die Wahrscheinlichkeit von Sekundärstrukturen bei verschiedenen pH-Werten zu machen. Zusätzlich zu der Untersuchung neuer Liganden wurde auch die Struktur des TCF4/Beta-Catenin Komplexes näher untersucht. Hierfür wurden sowohl röntgenkristallographische Experimente verwendet, als auch die selektive Reduzierung von Lysin-Seitenkette mit 13HCHO, welche ein Messen des daraus resultierenden 13C-1H Spektrums erlaubt. Um die Relevanz meiner Untersuchungen zu unterstreichen, werden die sich ergebenden Möglichkeiten für die Entwicklung eines neuen Antitumormittels mit möglichst hohem Sicherheitsprofil erörtert.Aberrant Wnt/Beta-Catenin signaling is observed in a wide spectrum of human malignancies. Activation of this pathway is involved in colon and ovarian cancer. Therefore, inhibitors of the TCF4/Beta-Catenin interaction are of great potential as antitumor agents. We used the recently described protein meta-structure approach to identify novel small molecule compounds as binders for Beta-Catenin. The identified ligands have been tested for binding with the target protein using 1D 1H-STD, 1D AFP NOESY, 2D NOESY and 19F-NMR. The identified binders were demonstrated to compete with the authentic Beta-Catenin binding partner TCF4. In addition, a dynamic combinatorial library has been designed to synthesize new ligands for Beta-Catenin. Moreover, 2D & 3D-NMR experiments were used to assign the backbone signals of full length TCF4 and two different truncations at different pH values. The data obtained from assignment at pH=4.5 and pH=2 were compared with the predicted random coil shifts. Secondary structure propensities were also compared which allowed us to estimate changes in secondary structure propensities upon pH change. Finally, further structural insight into the TCF4/Beta-Catenin complex was provided by a combined X-ray crystallography and NMR study employing selective lysine reductive-methylation reaction. To highlight the importance of our work, the resulting prospects for the development of new powerful anticancer drugs with a high safety profile will also be discussed

Selektoren zur chiralen Erkennung & Synthese und Charakterisierung von Adamantan-2,4-diamin

The principle of chiral recognition is of central significance in enantioselective catalysis. Therefore, high efficiency in terms of synthesis, separation and analysis of chiral compounds plays an important role. In the first chapter, novel chiral stationary phases for enantioselective separation by gas chromatography will be presented. The chromatographic data provided information on enantiospecific interactions between chiral selectors and selectands. NMR experiments with these selectors in presence of corresponding products of enantioselective catalysis allowed transferring the results from the gas to the liquid phase. This shows that enantioselective gas chromatography can be used as a tool for the screening of selector-selectand interactions. The information obtained was directly applied for the design of a new ligand that can be used in rhodium catalyzed enantioselective hydrogenation. The effect of chiral selectors on dynamic systems was investigated in a double aldol reaction. Therefore, a stereochemical bias was applied onto a dynamic catalyst by addition of an external selector. The induced orientation of the catalyst is reflected the enantiomeric ratio of the chiral product. The excellent separation performance and enantiospecific interactions between the valine based selector with many derivatized amino acids included this structural element covalently bound on a stereodynamic biaryl ligand to give a specifically designed ligandfor asymmetric hydrogenation. This system enables the product of the reaction to transfer chiral information to the coordination complex of catalyst and substrate by interaction with the selectors. In this manner, the chiral information of the product can be transferred on the prochiral substrate. In the second chapter, an accessible chiral derivative of 2,4-disubstitued adamantine diamine was synthesized and separated into its four stereoisomers by reversible derivatization. Combination of unique symmetry and stability make adamantane an interesting structural element in drugs. The isolated and fully characterized stereoisomers of adamantan-2,4-diamine are currently used in medical studies in collaboration as DNA-binder trough influence on the melting temperature of the DNA double helix

External Validation of a Predictive Model for Acute Pancreatitis Risk in Patients With Severe Hypertriglyceridemia

Objective: We previously developed a predictive model to assess the risk of developing acute pancreatitis (AP) in patients with severe hypertriglyceridemia (HTG). In this study, we aimed to externally validate this model. Methods: The validation cohort included cross-sectional data between 2013 and 2017. Adult patients (≥18 years old) with triglyceride levels ≥1,000 mg/dL were identified. Based on our previous 4-factor predictive model (age, triglyceride [TG], excessive alcohol use, and gallstone disease), we estimated the probability of developing AP. Model performance was assessed using area under receiver operating characteristic curve (AUROC). Results: In comparison to the original cohort, patients in the validation cohort had more prevalent acute pancreatitis (16.2% versus 9.2%; P<.001) and gallstone disease (7.5% versus 2.1%; P<.001). Other characteristics were comparable and not statistically significant. The AUROCs were almost identical: 0.8337 versus 0.8336 in the validation and the original cohorts, respectively. In univariable analyses, the highest increase in odds of AP was associated with HTG, followed by gallstones, excessive alcohol use, and younger age. Conclusion: This study externally validates the 4-factor predictive model to estimate the risk of AP in adult patients with severe HTG (TG ≥1,000 mg/dL). Younger age was confirmed to place patients at high risk of AP. The clinical risk categories suggested in this study may be useful to guide treatment options