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Masterarbeit
Vergleich & Anpassung zweier Strategien zur Anomalieerkennung in Lastgängen basierend auf Verfahren aus den Bereichen Machine-Learning und Statistik
(2020-11)
In dieser Masterarbeit werden zwei Strategien zur Anomalieerkennung in Lastgängen ausgewertet. Dazu nutzt Strategie 1 das künstliche neuronale Netzwerk LSTM (Long Short-Term Memory) mit Datenzeitraum von einem Monat (1M) bzw. drei Monaten (3M) trainiert und Strategie 2 das Glättungsverfahren PEWMA (Probalistic Exponential Weighted Moving Average) zur Schätzung des zu untersuchenden Lastgangmonats. Durch den Vergleich mit Originallastgangdaten werden Residuen bzw. summierte Residuen der Sequenzlängen zwei, vier, sechs ...
Aufsatz
Electron beam welding of Fe–Mn–Al–Ni shape memory alloy: Microstructure evolution and shape memory response
(2017-07-03)
The present study reports on the impact of abnormal grain growth (AGG) on the microstructural evolution following electron beam (EB) welding of Fe–Mn–Al–Ni shape memory alloy (SMA). Polycrystalline sheet-like material was EB-welded and a cyclic heat treatment, studied in previous work, was conducted for inducing AGG and a bamboo-like microstructure, respectively. Optical and electron microscopy were carried out to characterize the prevailing microstructure upon cyclic heat treatment. For characterization of the ...
Aufsatz
Processing effects on tensile superelastic behaviour of Fe43.5Mn34Al15 ± XNi7.5∓X shape memory alloys
(2019)
Fe₄₃.₅Mn₃₄Al₁₅Ni₇.₅ was introduced in the current decade as a new superelastic alloy with great applicative potential due to: (i) superelastic behaviour over a thermal range of 200°C and (ii) recoverable strains up to 9.7 %. One of the key factors in enhancing the superelastic response of several shape memory alloys (SMAs) is the formation of an oligocrystalline structure, i.e. without triple junctions between grains, which is the result of an abnormal grain growth (AGG) process that can be induced by cyclic heat ...
Aufsatz
Design of novel materials for additive manufacturing - Isotropic microstructure and high defect tolerance
(2018-01-22)
Electron Beam Melting (EBM) is a powder-bed additive manufacturing technology enabling the production of complex metallic parts with generally good mechanical properties. However, the performance of powder-bed based additively manufactured materials is governed by multiple factors that are difficult to control. Alloys that solidify in cubic crystal structures are usually affected by strong anisotropy due to the formation of columnar grains of preferred orientation. Moreover, processing induced defects and porosity ...
Aufsatz
Shape memory effect and superelasticity in high-strength FeNiCoAlTi single crystals hardened by nanoparticles
(2019-11-19)
For [001]-oriented single crystals of Fe-28Ni-17Co-11.5Al-2.5Ti (at %) alloy in tension, it was shown that particles of the γ’-phase with a size of 4–6 nm lead to the appearance of superelasticity, with a strain of εSE=4.5% and a shape memory effect of εSME=5.9%. Increasing the particle size to 10–12 nm reduces εSE to 3.6% and εSME to 3.5%. The paper discusses the causes of the influence of particle size on the reversible strain.
Aufsatz
Excellent superelasticity in a Co-Ni-Ga high-temperature shape memory alloy processed by directed energy deposition
(2020-04-30)
A Co-Ni-Ga high-temperature shape memory alloy has been additively manufactured by directed energy deposition. Due to the highly anisotropic microstructure, i.e. columnar grains featuring a strong near-⟨001⟩ texture in build direction, the as-built material is characterized by a very low degree of constraints and, thus, shows excellent superelasticity without conducting a post-process heat treatment. As characterized by in situ deformation testing and post-mortem microstructural analysis, additive manufacturing ...
Video
CONVERSOS Y CREYENTES
(2020-06-20)
1: Posmodernidad y posmodernismo
2: La obra de los arquitectos “conversos”
3: La obra de los arquitectos “creyentes”
Juan Carlos Doblado
Arquitecto de la Universidad Ricardo Palma, con una maestría en la Universidad Nacional de Ingeniería.
Fue Medalla de Oro en el Foro Mundial de Jóvenes Arquitectos (1993) y miembro fundador de ARQUIDEA.
Ha ganado el Hexágono de Bronce en la Bienal de Arquitectura de Lima y se desempeña como profesor de diseño arquitectónico en la Universidad Peruana de Ciencias Aplicadas y ...
Aufsatz
On data-driven nonlinear uncertainty modeling: Methods and application for control-oriented surface condition prediction in hard turning
(2020-10-16)
In this article, two data-driven modeling approaches are investigated, which allow an explicit modeling of uncertainty. For this purpose, parametric Takagi-Sugeno multi-models with bounded-error parameter estimation and nonparametric Gaussian process regression are applied and compared. These models can for instance be used for robust model-based control design. As an application, the prediction of residual stresses during hard turning depending on the machining parameters and the initial hardness is considered.
Working paper
Dienstleistungen rund um das Automobil.
(2017)
Many contributions to the history of the automobile focus on production. Instead, this paper explores various kinds of services that supports automobile drivers to use their vehicles. The service network consists of automobil dealers, the automobile workshops, fueling stations, tire dealers and garage stations as service centers. The mass production of automobiles was supplemented by mass distribution. A special structure of automobile dealers the automobile producers had to establish. The paper explores the conflicts ...
Dissertation
A Comparative Study on Internationalization and the Role of International Offices at Selected Middle Eastern and German Universities
(2012-07-03)
Internationalization of higher education has become one of the most important policies for institutions of higher education worldwide. Though universities are international by nature, the need for intensified quality activities of international nature has promoted internationalization to be under spotlight of researchers, administrators and policy makers and to be an area for research. Each institution follows its certain way to govern its international affairs. Most Universities, especially in the 'Developed World' ...