bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic Analysis of Multibody Rotor-Bearing System
Authors: Mohiuddin M. A. , Khulief Y. A. 
Published: February 2021

Abstract
A multibody formulation of a rotor-bearing system of interconnected flexible and rigid components is presented. The elastic shaft is modelled by the finite element method where shear stiffness, torsional stiffness and the gyroscopic effects are considered. An application to a large-scale rotor-bearing system is presented. Complex modal transformations were invoked to obtain a reduced-order dynamic model. The dynamic responses due step and impulse excitations were obtained using both the full-order and the reduced-order models. Comparisons are presented to verify the validity and accuracy of the reduced-order modal form.
Parameter Identification for Multibody Dynamic Systems
Authors: Serban Radu , Freeman Jeffrey S. , Negrut Dan 
Published: February 2021

Abstract
This paper presents a parameter identification technique for multibody dynamic systems, based on a nonlinear least-square optimization procedure. The procedure identifies unknown parameters in the differential-algebraic multibody system model by matching the acceleration time history of a point of interest with given data. Derivative information for the optimization process is obtained through dynamic sensitivity analysis. Direct differentiation methods are used to perform the sensitivity analysis. Examples of the procedure are presented, applying the technique both to perfect data; i.e. data produced by the assumed model with the optimal choice of parameters, and to experimental data; i.e. data measured on the real system and thus subject to noise and modelling imperfections.
Reduction of Forced Vibration Response by Optimum Balance of Linkage and Optimum Design of System
Authors: Zhang She-min , Morita Nobuyoshi , Torii Takao 
Published: February 2021

Abstract
This paper proposes a new method to reduce the forced vibration response of frame of linkage. It is that the root-mean-square (RMS) value of binary maximum (Bmax) of forced vibration response at a series of angular velocities is taken as the objective function, and the counterweight mass parameters of links and the stiffness factors are used as design variables. Then, it is found out that the responses are related not only to the Bmax value of shaking forces, but also to the shape of curve of shaking forces. The calculation results are compared with those of two other methods used in the reduction of forced vibration response by optimized balance of linkages, and it is shown that the new method can significantly reduce the responses of frame of linkage.
Effects of Noise on Measured Ritz Vectors
Authors: Zimmerman David C. , Cao Timothy T. 
Published: February 2021

Abstract
Ritz vectors offer many advantages over the traditional mode shapes in the areas of model reduction and structural dynamic simulation. Building upon the recent development of an experimental method to extract Ritz vectors from measured dynamic response data, these vectors were also demonstrated to offer great potential in the areas of finite element model correlation and structural damage detection. In this paper, a Monte Carlo simulation is performed to study the accuracy and stability of Ritz vectors extracted from this new procedure using noise corrupted response data. The statistical variation of Ritz parameters and modal parameters extracted from the same data is made to assess the sensitivity of Ritz vector extraction to measured noise.
Structural Dynamics and Damage Detection of Foam-Rigidized Deployable Aerospace Structures
Authors: Main John A. , Smith Suzanne Weaver , Chapman Alexander L. , Hobbs Kenneth Patrick 
Published: February 2021

Abstract
The basic advantage of deployable structures, their compact stowed size relative to their final deployed size, presents a significant advantage to the aerospace designer. Extremely large structures that stow into very small volumes for launch are particularly feasible with one particular type of deployable, the inflated structure. However, it is difficult to advocate the use a purely inflated structure for an orbital mission because of the risk of micrometeor puncture.
Rigidizing the structure in some fashion addresses this fragility issue. Design and operational issues with respect to foam-rigidized aerospace structures are investigated in this paper. The structures are fabricated from flexible Kapton film that is formed into a cylindrical shell. The shell is injected with a hardening urethane foam to form a composite strut.
The results of both static and dynamic tests of four test coupons cut from foam rigidized struts are presented. The experimentally determined structural properties are then input into a finite–element model to gain insight into the dynamic behavior of a realistic inflated–rigidized structure.
As with all structures touted for aerospace use, the survivability of foam–rigidized structures in the orbital environment is of interest. This issue is investigated by damaging the test coupons in a controlled fashion and then again experimentally evaluating the static and dynamic material properties. These properties are used for sections of the finite–element model to represent damage to the structure. An evaluation of the possibility of vibration–based damage assessment is included.
Order Reduction of Identified Interval Model for Systems With Uncertain Parameters
Authors: Lew Jiann-Shiun , Lim Kyong B. 
Published: February 2021

Abstract
This paper addresses the issue of modeling a system with parametric uncertainty via a reduced-order interval model. A system with parametric uncertainty is represented by intervals of transfer function coefficients obtained directly from time-domain response data. An approach based on the sensitivity of a performance specification to the identified uncertain parameters is developed for efficiently analyzing the identified interval model. This approach can significantly reduce the computational effort required by interval system techniques and hence simplify its robust control design. A torque converter clutch system with friction uncertainty is given to fix ideas.
A Method for Identification of Powerplant Joint Properties Using FRF Data and FEM Model
Authors: Takahashi Yukitaka , Suzuki Toshibumi , Tsukahara Masayoshi 
Published: February 2021

Abstract
Vibration characteristics of a powerplant, an important parameter to evaluate the booming noise and the durability of each parts of an automobile is a major field of simulation analysis using the finite element method (FEM). Overall vibration characteristics, however, depend heavily on the joint properties when it comes to the analysis of complicated structures like a powerplant where a number of parts are incorporated. Among other characteristics, it is extremely difficult to conduct accurate identification of the damping characteristics of the joint area, which had been the result of inaccurate analyses.
This paper reports a newly established method to solve these problems through the application of frequency response function (FRF) data and FEM models. Also described is the result of application of the method to the evaluation of a transversely-mounted in-line four-cylinder engine in a front-wheel drive layout. The application revealed that the joint properties can be identified fairly accurately, which in turn allows reliable prediction of vibration level.
Numerical Algorithms for Subspace State Space System Identification (N4SID)
Authors: Van Overschee Peter , De Moor Bart , Favoreel Wouter 
Published: February 2021

Abstract
We present the basic notions on subspace identification algorithms for linear systems. These methods estimate state sequences or extended observability matrices directly from the given data, through an orthogonal or oblique projection of the row spaces of certain block Hankel matrices into the row spaces of others. The extraction of the state space model is then achieved through the solution of a least squares problem. These algorithms can be elegantly implemented using well-known numerical linear algebra algorithms such as the LQ- and singular value decomposition. The paper aims at giving an overview of the methodologies used in time domain subspace identification. A short overview of frequency domain subspace identification results is also presented.
Garteur Group on Ground Vibration Testing: Results From the Test of a Single Structure by 12 Laboratories in Europe
Authors: Balmès Etienne , Wright Jan R. 
Published: February 2021

Abstract
In an effort to assess state of the art methodologies for the experimental determination of modal characteristics, 12 European groups, most of them working in the area of aircraft ground vibration tests for flutter certification, participated in a GAR-TEUR action group whose main activity was to have independent tests of a single representative structure. Design considerations for the common structure are first detailed. Estimates of frequency response functions and modal characteristics are then compared and show a level of consistency that is much higher than those reported in previous similar exercises.
The Wide World of Translating Webs
Authors: Mote C. D. , Mockensturm Eric 
Published: February 2021

Abstract
Our webs are wide, very thin, two-dimensional, continua arising commonly as a material in transport in machine systems. Though they are thin, webs often require modeling as plates or shells, albeit very thin and flexible ones, because even small bending stiffness distinguishes their behaviors from membranes in critical ways. Technological applications generating interest in web mechanics include the manufacture and handling of paper where wide sheets are transported by rollers at the highest possible speed, thereby maximizing productivity. Material handling problems of a similar type also arise with tissues, films, magnetic media, textiles, fabrics, polymer sheets, and the like. In a technical world pressing for ever higher speeds of stable transport, the web instabilities of wrinkling and flutter commonly bound the productivity of a technological process. These instabilities can result in permanent damage or rupture of the material and disruption of the manufacturing process. Consequently, the presentation today addresses some findings on webs that relate to their modeling, the prediction and causes of wrinkling, and the effect of roller misalignment on web behavior during transport. To allow us to maintain this focus, the rich collection of works on membrane structures, including modeling of inflated membranes, space structures and fiber reinforced membranes will not be part of our discussion. For attention to interesting membrane developments readers might examine Reissner (1938), Steigmann and Pipkin (1989), Jenkins and Leonard (1991), Li and Steigmann (1993), and Haseganu and Steigmann (1994). The most important topic of web flutter caused by air flows over the web surfaces will not be addressed, though recent experimental findings can be found in Chang and Moretti (1992) and Nguyen (1993). Theories modeling the flow and web in these coupled problems tend to underestimate the flutter speeds. This problem area is one of great importance.
Thermal management with and without servo-controlled system in preterm infants immediately after birth: a multicentre, randomised controlled study
Authors: Cavallin Francesco , Doglioni Nicoletta , Allodi Alessandra , Battajon Nadia , Vedovato Stefania , Capasso Letizia , Gitto Eloisa , Laforgia Nicola , Paviotti Giulia , Capretti Maria Grazia , Gizzi Camilla , Villani Paolo Ernesto , Biban Paolo , Pratesi Simone , Lista Gianluca , Ciralli Fabrizio , Soffiati Massimo , Staffler Alex , Baraldi Eugenio , Trevisanuto Daniele 
Published: February 2021

BackgroundThe thermal servo-controlled systems are routinely used in neonatal intensive care units (NICUs) to accurately manage patient temperature, but their role during the immediate postnatal phase has not been previously assessed.ObjectiveTo compare two modalities of thermal management (with and without the use of a servo-controlled system) immediately after birth.Study design and settingMulticentre, unblinded, randomised trial conducted 15 Italian tertiary hospitals.ParticipantsInfants with estimated birth weight <1500 g and/or gestational age <30+6weeks.InterventionThermal management with or without a thermal servo-controlled system during stabilisation in the delivery room.Primary outcomeProportion of normothermia at NICU admission (axillary temperature 36.5°C–37.5°C).ResultsAt NICU admission, normothermia was achieved in 89/225 neonates (39.6%) with the thermal servo-controlled system and 95/225 neonates (42.2%) without the thermal servo-controlled system (risk ratio 0.94, 95% CI 0.75 to 1.17). Thermal servo-controlled system was associated with increased mild hypothermia (36°C–36.4°C) (risk ratio 1.48, 95% CI 1.09 to 2.01).ConclusionsIn very low birthweight infants, thermal management with the servo-controlled system conferred no advantage in maintaining normothermia at NICU admission, while it was associated with increased mild hypothermia. Thermal management of preterm infants immediately after birth remains a challenge.Trial registration numberNCT03844204
Use of patient complaints to identify diagnosis-related safety concerns: a mixed-method evaluation
Authors: Giardina Traber D , Korukonda Saritha , Shahid Umber , Vaghani Viralkumar , Upadhyay Divvy K , Burke Greg F , Singh Hardeep 
Published: February 2021

BackgroundPatient complaints are associated with adverse events and malpractice claims but underused in patient safety improvement.ObjectiveTo systematically evaluate the use of patient complaint data to identify safety concerns related to diagnosis as an initial step to using this information to facilitate learning and improvement.MethodsWe reviewed patient complaints submitted to Geisinger, a large healthcare organisation in the USA, from August to December 2017 (cohort 1) and January to June 2018 (cohort 2). We selected complaints more likely to be associated with diagnostic concerns in Geisinger’s existing complaint taxonomy. Investigators reviewed all complaint summaries and identified cases as ‘concerning’ for diagnostic error using the National Academy of Medicine’s definition of diagnostic error. For all ‘concerning’ cases, a clinician-reviewer evaluated the associated investigation report and the patient’s medical record to identify any missed opportunities in making a correct or timely diagnosis. In cohort 2, we selected a 10% sample of ‘concerning’ cases to test this smaller pragmatic sample as a proof of concept for future organisational monitoring.ResultsIn cohort 1, we reviewed 1865 complaint summaries and identified 177 (9.5%) concerning reports. Review and analysis identified 39 diagnostic errors. Most were categorised as ‘Clinical Care issues’ (27, 69.2%), defined as concerns/questions related to the care that is provided by clinicians in any setting. In cohort 2, we reviewed 2423 patient complaint summaries and identified 310 (12.8%) concerning reports. The 10% sample (n=31 cases) contained five diagnostic errors. Qualitative analysis of cohort 1 cases identified concerns about return visits for persistent and/or worsening symptoms, interpersonal issues and diagnostic testing.ConclusionsAnalysis of patient complaint data and corresponding medical record review identifies patterns of failures in the diagnostic process reported by patients and families. Health systems could systematically analyse available data on patient complaints to monitor diagnostic safety concerns and identify opportunities for learning and improvement.
Finger Rescue Using the Induced Membrane Technique for Osteomyelitis of the Hand
Authors: Toyama Takeyasu , Hamada Yoshitaka , Horii Emiko , Kinoshita Riichiro , Saito Takanori 
Published: February 2021

Background: The induced membrane technique is now commonly used for large diaphyseal bone defects. Recently, several papers reported using the induced membrane technique for hand surgery. We applied this technique with some modifications to treat osteomyelitis of the phalanges. Methods: This study included six men and one woman with a mean age of 56 years. The causes of osteomyelitis included animal bite (n = 3), trauma (n = 3), and an indwelling needle (n = 1). Two-staged surgeries were performed, including an initial stage with radical debridement of the infected tissue and placement of a cement spacer into the bone defect. Four weeks after the first stage, a bone graft was performed. A bone block with cortex was harvested from the iliac crest or radius, and costal cartilage was used for proximal interphalangeal (PIP) joint arthroplasty in two cases. Grafted bones were fixed with a mini screw or an external fixator. Results: In all cases, the infection subsided, and bone union was obtained within two to three months. No absorption of the grafted bone was observed. In the two cases with PIP joint defect, joint motion without pain was preserved at 56° and 26°. Conclusions: A short interval between the two surgical stages of the induced membrane technique could be advantageous for patients in terms of time and financial burden and early rehabilitation of movement. Cortico-cancellous bone grafts were able to maintain bone length and stability with screw fixation. In the cases with PIP joint defects, instead of arthrodesis, we performed PIP arthroplasty using costal cartilage, eventually obtained some motion without pain. The induced membrane technique was useful and technically feasible for treating osteomyelitis in the hand, and secondary joint reconstruction was possible to obtain some motion.
Chapter 3.1a Antarctic Peninsula and South Shetland Islands: volcanology
Authors: Leat Philip T. , Riley Teal R. 
Published: February 2021

Abstract

The voluminous continental margin volcanic arc of the Antarctic Peninsula is one of the major tectonic features of West Antarctica. It extends from the Trinity Peninsula and the South Shetland Islands in the north to Alexander Island and Palmer Land in the south, a distance of
c.
1300 km, and was related to east-directed subduction beneath the continental margin. Thicknesses of exposed volcanic rocks are up to
c.
1.5 km, and the terrain is highly dissected by erosion and heavily glacierized. The arc was active from Late Jurassic or Early Cretaceous times until the Early Miocene, a period of climate cooling from subtropical to glacial. The migration of the volcanic axis was towards the trench over time along most of the length of the arc. Early volcanism was commonly submarine but most of the volcanism was subaerial. Basaltic–andesitic stratocones and large silicic composite volcanoes with calderas can be identified. Other rock associations include volcaniclastic fans, distal tuff accumulations, coastal wetlands and glacio-marine eruptions.

Other groups of volcanic rocks of Jurassic age in Alexander Island comprise accreted oceanic basalts within an accretionary complex and volcanic rocks erupted within a rift basin along the continental margin that apparently predate subduction.
Targeting the HuR Oncogenic Role with a New Class of Cytoplasmic Dimerization Inhibitors
Authors: Filippova Natalia , Yang Xiuhua , Ananthan Subramaniam , Calano Jennifer , Pathak Vibha , Bratton Larry , Vekariya Rakesh H. , Zhang Sixue , Ofori Edward , Hayward Emily N. , Namkoong David , Crossman David K. , Crowley Michael R. , King Peter H. , Mobley James , Nabors Louis B. 
Published: February 2021

Abstract

The development of novel therapeutics that exploit alterations in the activation state of key cellular signaling pathways due to mutations in upstream regulators has generated the field of personalized medicine. These first-generation efforts have focused on actionable mutations identified by deep sequencing of large numbers of tumor samples. We propose that a second-generation opportunity exists by exploiting key downstream “nodes of control” that contribute to oncogenesis and are inappropriately activated due to loss of upstream regulation and microenvironmental influences. The RNA-binding protein HuR represents such a node. Because HuR functionality in cancer cells is dependent on HuR dimerization and its nuclear/cytoplasmic shuttling, we developed a new class of molecules targeting HuR protein dimerization. A structure–activity relationship algorithm enabled development of inhibitors of HuR multimer formation that were soluble, had micromolar activity, and penetrated the blood–brain barrier. These inhibitors were evaluated for activity validation and specificity in a robust cell-based assay of HuR dimerization. SRI-42127, a molecule that met these criteria, inhibited HuR multimer formation across primary patient-derived glioblastoma xenolines (PDGx), leading to arrest of proliferation, induction of apoptosis, and inhibition of colony formation. SRI-42127 had favorable attributes with central nervous system penetration and inhibited tumor growth in mouse models. RNA and protein analysis of SRI-42127–treated PDGx xenolines across glioblastoma molecular subtypes confirmed attenuation of targets upregulated by HuR. These results highlight how focusing on key attributes of HuR that contribute to cancer progression, namely cytoplasmic localization and multimerization, has led to the development of a novel, highly effective inhibitor.

Significance:
These findings utilize a cell-based mechanism of action assay with a structure–activity relationship compound development pathway to discover inhibitors that target HuR dimerization, a mechanism required for cancer promotion.
Clinicopathologic and Genomic Analysis of TP53-Mutated Endometrial Carcinomas
Authors: Momeni-Boroujeni Amir , Dahoud Wissam , Vanderbilt Chad M. , Chiang Sarah , Murali Rajmohan , Rios-Doria Eric V. , Alektiar Kaled M. , Aghajanian Carol , Abu-Rustum Nadeem R. , Ladanyi Marc , Ellenson Lora H. , Weigelt Britta , Soslow Robert A. 
Published: February 2021

Abstract

Purpose:
Copy number–high endometrial carcinomas were described by The Cancer Genome Atlas as high-grade endometrioid and serous cancers showing frequent copy-number alterations (CNA), low mutational burden (i.e., non-hypermutant), near-universal TP53 mutation, and unfavorable clinical outcomes. We sought to investigate and compare the clinicopathologic and molecular characteristics of non-hypermutant TP53-altered endometrial carcinomas of four histologic types.

Experimental Design:
TP53-mutated endometrial carcinomas, defined as TP53-mutant tumors lacking microsatellite instability or pathogenic POLE mutations, were identified (n = 238) in a cohort of 1,239 endometrial carcinomas subjected to clinical massively parallel sequencing of 410–468 cancer-related genes. Somatic mutations and CNAs (n = 238), and clinicopathologic features were determined (n = 185, initial treatment planning at our institution).

Results:
TP53-mutated endometrial carcinomas encompassed uterine serous (n = 102, 55.1%), high-grade endometrial carcinoma with ambiguous features/not otherwise specified (EC-NOS; n = 44, 23.8%), endometrioid carcinomas of all tumor grades (n = 28, 15.1%), and clear cell carcinomas (n = 11, 5.9%). PTEN mutations were significantly more frequent in endometrioid carcinomas, SPOP mutations in clear cell carcinomas, and CCNE1 amplification in serous carcinomas/EC-NOS; however, none of these genomic alterations were exclusive to any given histologic type. ERBB2 amplification was present at similar frequencies across TP53-mutated histologic types (7.7%–18.6%). Although overall survival was similar across histologic types, serous carcinomas presented more frequently at stage IV, had more persistent and/or recurrent disease, and reduced disease-free survival.

Conclusions:
TP53-mutated endometrial carcinomas display clinical and molecular similarities across histologic subtypes. Our data provide evidence to suggest performance of ERBB2 assessment in all TP53-mutated endometrial carcinomas. Given the distinct clinical features of serous carcinomas, histologic classification continues to be relevant.