Search

In the present paper a model based method for the on-line identification of malfunctions in rotor systems is proposed. The fault-induced change of the rotor system is taken into account by equivalent loads which are virtual forces and moments acting on the linear undamaged system model to generate a dynamic behaviour identical to the measured one of the damaged system.

Copyright of Baessler-Archiv is the property of Dietrich Reimer Verlag GMBH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

For slender beam-columns loaded by axial compressive forces, active buckling control provides a possibility to increase the maximum bearable axial load above that of a purely passive structure. In this paper, an approach for gain-scheduled buckling control of a slender beam-column with circular cross-section subject to time-varying axial loads is investigated experimentally. Piezo-elastic supports with integrated piezoelectric stack actuators at the beam-column ends allow an active stabilization in arbitrary lateral directions. The axial loads on the beam-column influence its lateral dynamic behavior and, eventually, cause the beam-column to buckle. A reduced modal model of the beam-column subject to axial loads including the dynamics of the electrical components is set up and calibrated with experimental data. Particularly, the linear parameter-varying open-loop plant is used to design a model-based gain-scheduled buckling control that is implemented in an experimental test setup. The beam-column is loaded by ramp- and step-shaped time-varying axial compressive loads that result in a lateral deformation of the beam-column due to imperfections, such as predeformation, eccentric loading or clamping moments. The lateral deformations and the maximum bearable loads of the beam-column are analyzed and compared for the beam-column with and without gain-scheduled buckling control or, respectively, active and passive configuration. With the proposed gain-scheduled buckling control it is possible to increase the maximum bearable load of the active beam-column by 19% for ramp-shaped axial loads and to significantly reduce the beam-column deformations for step-shaped axial loads compared to the passive structure. [ABSTRACT FROM AUTHOR]

In this paper, vibration attenuation of a beam with circular cross-section by resonantly shunted piezo-elastic supports is experimentally investigated for varying axial tensile and compressive beam loads. The beam's first mode resonance frequency, the general electromechanical coupling coefficient and static transducer capacitance are analyzed for varying axial loads. All three parameter values are obtained from transducer impedance measurements on an experimental test setup. Varying axial beam loads manipulate the beam's lateral bending stiffness and, thus, lead to a detuning of the resonance frequencies. Furthermore, they affect the general electromechanical coupling coefficient of transducer and beam, an important modal quantity for shunt-damping, whereas the static transducer capacitance is nearly unaffected. Frequency transfer functions of the beam with one piezoe-elastic support either shunted to an RL-shunt or to an RL-shunt with negative capacitance, the RLC-shunt, are compared for varying axial loads. It is shown that the beam vibration attenuation with the RLC-shunt is less influenced by varying axial beam loads and, therefore, is more robust against detuning. [ABSTRACT FROM AUTHOR]

The colonial monographs on Naga peoples and the colonial appropriation of artefacts in north-east India enhanced anthropological knowledge in Europe. This paper asks how far the 'decolonising the museum' approach can be applied in studying Naga collections in European museums and in facilitating critical engagement with ethnographic objects from Naga communities in both Western and Indian museums. There has been a regeneration of interest in the colonial history of Naga collections among European/New World academics and in ethnographic museums in the late 1980s, mid 2000s and currently in Humboldt Lab (2015) and Forum (2022), and among Naga communities themselves. The paper examines how the contrasting historical trajectories, positions and modern consequences play out1. [ABSTRACT FROM AUTHOR]

Undesired vibration may occur in lightweight structures due to excitation and low damping. For the purpose of lateral vibration attenuation in beam structures, piezoelectric transducers shunted to negative capacitances can be an appropriate measure. In this paper, a new concept for lateral vibration attenuation by integrated piezoelectric stack transducers in the elastic support of a beam with circular cross-section is presented. In the piezoelastic support, bending of the beam in an arbitrary direction is transformed into a significant axial deformation of three stack transducers and, thus, the beam’s surface may remain free from transducers. For multimodal vibration attenuation, each piezoelectric transducer is shunted to a negative capacitance. It is shown by numerical simulation and experiment that the concept of an elastic beam support with integrated shunted piezoelectric stack transducers is capable of reducing the lateral vibration of the beam in an arbitrary direction. [ABSTRACT FROM AUTHOR]

Buckling of slender beam-columns subject to axial compressive loads represents a critical design constraint for light-weight structures. Active buckling control provides a possibility to stabilize slender beam-columns by active lateral forces or bending moments. In this paper, the potential of active buckling control of an axially loaded beam-column with circular solid cross-section by piezo-elastic supports is investigated experimentally. In the piezo-elastic supports, lateral forces of piezoelectric stack actuators are transformed into bending moments acting in arbitrary directions at the beam-column ends. A mathematical model of the axially loaded beam-column is derived to design an integral linear quadratic regulator (LQR) that stabilizes the system. The effectiveness of the stabilization concept is investigated in an experimental test setup and compared with the uncontrolled system. With the proposed active buckling control it is possible to stabilize the beam-column in arbitrary lateral direction for axial loads up to the theoretical critical buckling load of the system. [ABSTRACT FROM AUTHOR]

A correction is presented to the article "Engaging with Ethnographic Museum Objects from Erstwhile Naga Hills: From Imperial, Colonial and Postcolonial Eras to Contemporary Reimagining" which appeared in the previous issue of the periodical.

Nonparametric estimation of a quantile qm(X),\alpha of a random variable m(X) is considered, where m: \mathbb {R}^{d}\rightarrow \mathbb {R} is a function, which is costly to compute and X is an \mathbb R^d -valued random variable with known distribution. Monte Carlo surrogate quantile estimates are considered, where in a first step, the function m is estimated by some estimate (surrogate) mn , and then, the quantile qm(X),\alpha is estimated by a Monte Carlo estimate of the quantile qmn(X),\alpha . A general error bound on the error of this quantile estimate is derived, which depends on the local error of the function estimate mn , and the rates of convergence of the corresponding Monte Carlo surrogate quantile estimates are analyzed for two different function estimates. The finite sample size behavior of the estimates is investigated in simulations. [ABSTRACT FROM AUTHOR]

Veterinary Serum and Vaccine Research Institute (VSVRI) objected to producing highly efficient vaccines from reference or local isolates according to the international specifications for protecting animals and poultry against different diseases and preparing combined vaccines to save effort, time and money. VSVRI produces various types of vaccines such as live attenuated viral poultry, live attenuated viral animal vaccines, live attenuated Bacterial animal vaccines and Inactivated viral animal vaccines. These vaccines are subjected to quality assurance through seven methods with different techniques. Validity and measurement uncertainty for results were applied in the evaluation of results of the following: Titration of virus content using egg inoculation through Chorioallantoic Membrane (CAM), Intra-allantoic (IA) and Tissue Culture (TC). Determination of antibody titer using ELISA, HI and VNT techniques. Finally, enumeration of aerobic bacterial count for living attenuated Bacterial vaccine by culture technique. Homogeneity and stability results for all vaccines were accepted criteria according to TS/ISO 22117. The reproducibility component of the TC technique was higher while the Bias was lower than other different routes of egg inoculation. In conclusion, the accuracy of TC technique is better than the egg inoculation technique which will reflect on the measurement of uncertainty. There is no significant change in the final measurement uncertainty of different routes of egg inoculation. In comparison, there is a variance between bias accuracy and reproducibility precision due to the equation of measurement of uncertainty depending on all processes performed in test accuracy and precession. [ABSTRACT FROM AUTHOR]

Examines religious and ethnic identity in Karen communities of Northern Thailand. Influence of Christianity in Karen communities; Buddhism in Karen society; Christian missions in Northern Thailand.

The Naga objects of the Ethnological Museum in Berlin were collected in British colonial times during the second half of the 19~ century. There was a military Naga resistance against the British. Social and cultural Naga values changed dramatically during colonization mostly because of proselytization. It is rather unknown how the process of collecting the objects exactly worked. Objects were bought or bartered by Western collectors or were just given away by the Nagas because they were told by missionaries to get rid oitraditional items. At least in the case of the Berlin Naga collection, Naga objects were not taken away by military force. Early collectors as well as many of the British colonial officers and researchers had a paternalistic and sympathetic attitude towards the Nagas. After independence in 1947, India became the new colonial power for most Nagas. Christianity was established as a prominent marker of identity against the repressive Indian Hindu State. After times of neglect there is an emerging interest in old objects, even reinforced by the Baptist Church. So far no demand for restitution of any Naga objects is known. The cooperation with Naga communities started 2014 with the project on headhunting, an installation iii the Ethnological Museum as part of the Humboldt Lab. As a second step of cooperation between the Ethnological Museum Berlin and Naga communities. a Naga exhibition co-curated by a Naga artist will be on display in the Humboldt Forum. Future cooperation projects will be a common database used for sharing knowledge about the objects and hopefully the opportunity of residency programs for Naga researchers who might see the collection as a part of their cultural heritage. [ABSTRACT FROM AUTHOR]

Copyright of Futuro del Pasado: Revista Electrónica de Historia is the property of Futuro del Pasado: Revista Electronica de Historia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Berliner Gesellschaft für Anthropologie, Ethnologie und Urgeschichte (BGAEU) united very different disciplines, which were expanded and institutionalised by naturalists and physicians in the course of the nineteenth century. In ethnology the BGAEU had a central role in founding the Zeitschrift für Ethnologie and the Museum für Völkerkunde in Berlin. Above all, it worked for the development of an international scientific network through which information, photographs and objects were added to the Berlin collections. The peak of its activities came in the years just before the First World War. Its members, most of whom were medical doctors, met in monthly sessions where they exchanged information, lectured, and presented collections. Through its large library, the BGAEU also had a broad impact on a wider audience. Some of its members were involved in the activities of the German colonial empire, taking part in mainly archaeological excursions and visiting the then frequently held 'Völkerschauen'. The BGAEU played a decisive role in establishing the disciplines it represented at universities and museums. [ABSTRACT FROM AUTHOR]

The editorial staff of Computational Mechanics wishes to thank the following reviewers, who have helped to maintain and improve the quality of the journal in 2019. K.-U. Bletzinger Wu Zhou Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. [Extracted from the article]

Abstract: The starting point in uncertainty quantification is a stochastic model, which is fitted to a technical system in a suitable way, and prediction of uncertainty is carried out within this stochastic model. In any application, such a model will not be perfect, so any uncertainty quantification from such a model has to take into account the inadequacy of the model. In this paper, we rigorously show how the observed data of the technical system can be used to build a conservative non‐asymptotic confidence interval on quantiles related to experiments with the technical system. The construction of this confidence interval is based on concentration inequalities and order statistics. An asymptotic bound on the length of this confidence interval is presented. Here we assume that engineers use more and more of their knowledge to build models with order of errors bounded by l o g ( n ) / n. The results are illustrated by applying the newly proposed approach to real and simulated data. [ABSTRACT FROM AUTHOR]

This article compares Buddhist and Christian approaches to the drug problem among ethnic minorities in northern Thailand. Government programmes implemented through Buddhist monasteries aim to construct Buddhist subjects and realise agendas of national security in border areas. Yet, they also offer development support and access to resources. Meanwhile, gospel rehabilitation centres provide much-needed drug treatment services while drawing highlanders into transnational spheres of Christian fellowship. Consequently, I argue that the relationship between ethnic minorities and the state can be defined in terms of aspiration and negotiation, as well as resistance and evasion, as has been previously argued in the literature. [ABSTRACT FROM AUTHOR]

This article discusses the provenance and collection history of Tibetan, Indian and South East Asian artefacts bought from L. A. Waddell (1854-1938) by the Berlin Museum ofEthnology in 1906, focussing on the Tibetan material. As an Indian Army surgeon, amateur researcher and archaeologist stationed in British India, Waddell acquired Tibetan artefacts under highly problematic conditions in his position as "cultural consultant" during the 1903-04 British invasion of Tibet led by Col. Younghusband. But he also relied on alternative sources resulting from his first hand contacts with and academic knowledge of Tibetan culture. The collection, located today at the Ethnologisches Museum and the Museum für Asiatische Kunst in Berlin, consists of diverse object groups, ranging from ethnographic curios, including human remains, to the finest Indian sculpture. Considered as one of the foremost authorities on Tibet in his time, however, Waddell's books on the history of civilisation have caused controversy and contributed to fascist ideology. Therefore, the project, as a whole, seeks to investigate the role of the Berlin collection in the light of this dubious personality and to locate it within scientific, military and colonial collecting strategies. [ABSTRACT FROM AUTHOR]

This article focuses on the photograph collection of the Ethnologisches Museum in Berlin. A crucial element for this article was the development and implementation of a priority list on the recording and protection of the photo collection. Resulting from this priority list was a report on the planning and execution of the required conservational and restoring procedures. The article starts with an introduction of the topic, which shows the conditions encountered in the collection's materials from the 19th and 20th century. Furthermore, it provides insights into the in-house conservational practice. In this context, it illustrates which conservatory tasks are necessary and which tasks were achievable in the short run. The prompt implementation of these tasks is shown exemplarily through the restoration of a bundle of pictures from the Naga collection. [ABSTRACT FROM AUTHOR]

The Berlin Museum of Ethnology has a large collection of all kinds of wayang puppets from Java and Bali. Most of them originate from the 2nd half of the 19th century. The focus of this article is on the Javanese wayang kulit puppets. They were mainly sold to the museum by two Dutch collectors, Pleyte and Masthoff in the end of the 19th century. No curator so far published the fact that these puppets of the Berlin collection are smaller than the average figures from Java. In quality terms they are less refined than the usual puppets of that time. In fact they are called wayang kaper, puppets used for training the dalang, the puppet master. Nevertheless this collection seems to be one of the biggest wayang kaper sets in Western museums. The Balinese puppets, however, and especially the large wayanggolek puppet collection, some of them dating back to the middle of the 19th century, are high quality objects. As a joint project, one young Javanese dalang came in 2009 to the Berlin Museum of Ethnology to work on the Javanese wayang kulit collection. Parts of the wayang puppets will be seen in the future in the Humboldt Forum. The last time they were displayed was more than 10 years ago. [ABSTRACT FROM AUTHOR]

Artificially modified skulls are regarded today as valuable cultural relics, playing an important role in anthropological, ethnological and medicinal research. Based on features of recently identified intentionally modified skulls from [...]

Headhunting played a central role in the social organization, religion, and worldview of nearly all Dayak groups of Borneo. (1) A few groups decorated their trophy skulls in characteristic ways [...]