scholarly journals Robust Model Selection: Flatness-Based Optimal Experimental Design for a Biocatalytic Reaction

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 190
Author(s):  
Moritz Schulze ◽  
René Schenkendorf
Keyword(s):  
Experimental Design ◽  
Model Selection ◽  
Process Models ◽  
Differential Flatness ◽  
Optimal Controls ◽  
Parameter Uncertainties ◽  
Point Estimate Method ◽  
Biocatalytic Reaction ◽  
Improved Model ◽  
The Impact

Considering the competitive and strongly regulated pharmaceutical industry, mathematical modeling and process systems engineering might be useful tools for implementing quality by design (QbD) and quality by control (QbC) strategies for low-cost but high-quality drugs. However, a crucial task in modeling (bio)pharmaceutical manufacturing processes is the reliable identification of model candidates from a set of various model hypotheses. To identify the best experimental design suitable for a reliable model selection and system identification is challenging for nonlinear (bio)pharmaceutical process models in general. This paper is the first to exploit differential flatness for model selection problems under uncertainty, and thus translates the model selection problem to advanced concepts of systems theory and controllability aspects, respectively. Here, the optimal controls for improved model selection trajectories are expressed analytically with low computational costs. We further demonstrate the impact of parameter uncertainties on the differential flatness-based method and provide an effective robustification strategy with the point estimate method for uncertainty quantification. In a simulation study, we consider a biocatalytic reaction step simulating the carboligation of aldehydes, where we successfully derive optimal controls for improved model selection trajectories under uncertainty.

Identifying suboptimalities with factorial model comparison

2018 ◽  
Vol 41 ◽  
Author(s):  
Wei Ji Ma
Keyword(s):  
Experimental Design ◽  
Model Comparison ◽  
Process Models ◽  
Multiple Forms ◽  
Factorial Experimental Design ◽  
Factorial Model ◽  
Multiple Components ◽  
The Many

AbstractGiven the many types of suboptimality in perception, I ask how one should test for multiple forms of suboptimality at the same time – or, more generally, how one should compare process models that can differ in any or all of the multiple components. In analogy to factorial experimental design, I advocate for factorial model comparison.

scholarly journals Vibro-Acoustical Sensitivities of Stiffened Aircraft Structures Due to Attached Mass-Spring-Dampers with Uncertain Parameters

Aerospace ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 174
Author(s):  
Johannes Seidel ◽  
Stephan Lippert ◽  
Otto von Estorff
Keyword(s):  
System Response ◽  
Fuzzy Arithmetic ◽  
Parameter Uncertainties ◽  
Excitation Spectra ◽  
Radiated Noise ◽  
Linking Elements ◽  
Manufacturing Tolerances ◽  
Suitable Framework ◽  
Mass Spring ◽  
The Impact

The slightest manufacturing tolerances and variances of material properties can indeed have a significant impact on structural modes. An unintentional shift of eigenfrequencies towards dominant excitation frequencies may lead to increased vibration amplitudes of the structure resulting in radiated noise, e.g., reducing passenger comfort inside an aircraft’s cabin. This paper focuses on so-called non-structural masses of an aircraft, also known as the secondary structure that are attached to the primary structure via clips, brackets, and shock mounts and constitute a significant part of the overall mass of an aircraft’s structure. Using the example of a simplified fuselage panel, the vibro-acoustical consequences of parameter uncertainties in linking elements are studied. Here, the fuzzy arithmetic provides a suitable framework to describe uncertainties, create combination matrices, and evaluate the simulation results regarding target quantities and the impact of each parameter on the overall system response. To assess the vibrations of the fuzzy structure and by taking into account the excitation spectra of engine noise, modal and frequency response analyses are conducted.

The impact of commonly used air filters in eliminating the exposure to secondhand smoke constituents

2015 ◽  
Vol 17 (3) ◽  
pp. 543-551
Author(s):  
Chris A. Pritsos ◽  
Thivanka Muthumalage
Keyword(s):  
Experimental Design ◽  
Environmental Tobacco Smoke ◽  
Tobacco Smoke ◽  
Secondhand Smoke ◽  
Air Filters ◽  
Machine System ◽  
The Impact ◽  
Exposure To Secondhand Smoke

The use of microchip controlled TE-10 smoke machine system with 3R4F research cigarettes as a part of the experimental design in order to create an atmosphere with environmental tobacco smoke constituents.

Research and Improvement of the Keep-Right-Except-to-Pass Rule

2014 ◽  
Vol 915-916 ◽  
pp. 459-463
Author(s):  
He Quan Zhang
Keyword(s):  
Fluid Mechanics ◽  
Traffic Flow ◽  
Influence Factors ◽  
Traffic Model ◽  
Light Traffic ◽  
The Road ◽  
Model Based ◽  
Light Passing ◽  
Improved Model ◽  
The Impact

In order to deal with the impact on traffic flow of the rule, we compare the influence factors of traffic flow (passing, etc.) into viscous resistance of fluid mechanics, and establish a traffic model based on fluid mechanics. First, in heavy and light traffic, we respectively use this model to simulate the actual segment of the road and find that when the traffic is heavy, the rule hinder the further increase in traffic. For this reason, we make further improvements to the model to obtain a fluid traffic model based on no passing and find that the improved model makes traffic flow increase significantly. Then, the improved model is applied to the light traffic, we find there are no significant changes in traffic flow .In this regard we propose a new rule: when the traffic is light, passing is allowed, but when the traffic is heavy, passing is not allowed.

The impact of experimental design on assessing mechanism-based inactivation of CYP2D6 by MDMA (Ecstasy)

2006 ◽  
Vol 20 (6) ◽  
pp. 834-841 ◽  
Author(s):  
Linh M. Van ◽  
Amir Heydari ◽  
Jiansong Yang ◽  
Judith Hargreaves ◽  
Karen Rowland-Yeo ◽  
...  
Keyword(s):  
Experimental Design ◽  
The Impact

De impact van emotionele communicatie op de gepercipieerde oprechtheid en de reputatie van organisaties in crisis

2015 ◽  
Vol 43 (3) ◽  
Author(s):  
An-Sofie Claeys ◽  
Verolien Cauberghe
Keyword(s):  
Experimental Design ◽  
Crisis Communication ◽  
Experimental Studies ◽  
Emotional Communication ◽  
Discrete Emotions ◽  
Stealing Thunder ◽  
The Impact ◽  
A Company

The impact of emotional communication on perceived sincerity and reputation of organizations in crisis The impact of emotional communication on perceived sincerity and reputation of organizations in crisis This paper examines the impact of emotional communication of an organizational spokesperson in times of crisis on consumers’ perceptions of the spokesperson (i.e. sincerity) and the organization (i.e. reputation) by two experimental studies. The results of study one using a 2 (crisis timing strategy: thunder vs. stealing thunder) × 2 (rational vs. sad message) between-subjects experimental design illustrates that emotional crisis communication leads to less reputational damage than rational crisis communication (N = 168), but only if the organization self-discloses the incrementing information. In study two, the discrete emotions were manipulated in a self-disclosing setting to be sadness or anger (N = 60). The results of study two show that a company is perceived to take more responsibility for the crisis when the spokesperson expresses sadness instead of anger. The sincerity of the spokesperson/organization mediates these effects. Both studies stress the importance of emotional communication by spokespersons for organizations in crisis.

Optimisation of geotechnical surveys using a BIM-based geostatistical analysis

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Elham Mahmoudi ◽  
Marcel Stepien ◽  
Markus König
Keyword(s):  
Experimental Design ◽  
Data Structures ◽  
Digital Design ◽  
Ground Model ◽  
Content Type ◽  
Design Environments ◽  
Spatial Estimation ◽  
Computational Performance ◽  
Geological Models ◽  
The Impact

PurposeA principle prerequisite for designing and constructing an underground structure is to estimate the subsurface's properties and obtain a realistic picture of stratigraphy. Obtaining direct measure of these values in any location of the built environment is not affordable. Therefore, any evaluation is afflicted with uncertainty, and we need to combine all available measurements, observations and previous knowledge to achieve an informed estimate and quantify the involved uncertainties. This study aims to enhance the geotechnical surveys based on a spatial estimation of subsoil to customised data structures and integrating the ground models into digital design environments.Design/methodology/approachThe present study's objective is to enhance the geotechnical surveys based on a spatial estimation of subsoil to customised data structures and integrating the ground models into digital design environments. A ground model consisting of voxels is developed via Revit-Dynamo to represent spatial uncertainties employing the kriging interpolation method. The local arrangement of new surveys are evaluated to be optimised.FindingsThe visualisation model's computational performance is modified by using an octree structure. The results show that it adapts the structure to be modelled more efficiently. The proposed concept can identify the geological models' risky locations for further geological investigations and reveal an optimised experimental design. The modifications criteria are defined in global and local considerations.Originality/valueIt provides a transparent and repeatable approach to construct a spatial ground model for subsequent experimental or numerical analysis. In the first attempt, the ground model was discretised by a grid of voxels. In general, the required computing time primarily depends on the size of the voxels. This issue is addressed by implementing octree voxels to reduce the computational efforts. This applies especially to the cases that a higher resolution is required. The investigations using a synthetic soil model showed that the developed methodology fulfilled the kriging method's requirements. The effects of variogram parameters, such as the range and the covariance function, were investigated based on some parameter studies. Moreover, a synthetic model is used to demonstrate the optimal experimental design concept. Through the implementation, alternative locations for new boreholes are generated, and their uncertainties are quantified. The impact of the new borehole on the uncertainty measures are quantified based on local and global approaches. For further research to identify the geological models' risky spots, the development of this approach with additional criteria regarding the search neighbourhood and consideration of barriers and trends in real cases (by employing different interpolation methodologies) should be considered.

scholarly journals An Accounting Procedure for Bonds with a Double Currency Denomination in Accordance with the IFRS

2020 ◽  
Vol 7 (6) ◽  
pp. 55-63
Author(s):  
A. Yu. Kuz’min
Keyword(s):  
Interest Rate ◽  
Financial Reporting ◽  
Process Models ◽  
Financial Accounting ◽  
Practical Significance ◽  
Situational Analysis ◽  
Financial Reporting Standards ◽  
Mathematical Evaluation ◽  
The Impact ◽  
Accounting Procedure

The study is devoted to the development of accounting procedure and recording the financial results of bonds with a double currency denomination in accordance with International Financial Reporting standards (IFRS). The methodological base of the research includes system and dynamic-situational analysis, evaluation models of financial mathematics, accounting procedures of the theory of financial accounting. Based on the assumptions made at the formal mathematical level, this procedure is fully algorithmized, despite the ambiguity or impossibility of direct assessment of such basic accounting indicators as the initial estimate, the internal effective interest rate, and the amortized cost of a financial instrument. Considerable attention is paid to the issues of mathematical evaluation and reflection of financial results when preparing financial statements in accordance with the concept of amortized cost and effective interest rate, taking into account the impact of changes in the currency component in dynamics. The originality and uniqueness of the developed procedure is that it is applicable to the situations where coupon payments are paid several times a year. The theoretical and practical significance of the research is determined by the development of scientific and applied tools that include accounting and process models, evaluation algorithms and procedures that can be used by accounting and audit departments in practical work when solving problems of reporting in accordance with IFRS.

scholarly journals A Dockers Storage Performance Evaluation: Impact of Backing File Systems

2021 ◽  
pp. 8-17
Author(s):  
Amer Ramadan ◽  
Keyword(s):  
Performance Evaluation ◽  
Experimental Design ◽  
File Systems ◽  
Experimental Results ◽  
File Server ◽  
Storage Performance ◽  
File Access ◽  
Mail Server ◽  
The Impact ◽  
E Mail

This paper reports on an in-depth examination of the impact of the backing filesystems to Docker performance in the context of Linux container-based virtualization. The experimental design was a 3x3x4 arrangement, i.e., we considered three different numbers of Docker containers, three filesystems (Ext4, XFS and Btrfs), and four application workloads related to Web server I/O activity, e-mail server I/O activity, file server I/O activity and random file access I/O activity, respectively. The experimental results indicate that Ext4 is the most optimal filesystem, among the considered filesystems, for the considered experimental settings. In addition, the XFS filesystem is not suitable for workloads that are dominated by synchronous random write components (e.g., characteristical for mail workload), while the Btrfs filesystem is not suitable for workloads dominated by random write and sequential write components (e.g., file server workload).

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