Assessment of optimal design methods of viscous dampers

Viscous dampers are often used for seismic protection and performance enhancement of building frames. The optimal design of such devices requires the modelling and propagation of the uncertainties related to the earthquake hazard. Different approaches are available for the seismic input characterisation and for the probabilistic response evaluation. This work analyzes the effect of different characterizations of the seismic input and of the response evaluation on the design of dampers for building frames. The seismic input is represented as a stochastic process and the optimal damper properties are found via a reliability-based design procedure aiming at controlling the frame performance while limiting the damper cost. Two simplified approaches are used to design the viscous damper of a multi-storey steel frame and the design results are compared with those obtained by considering a rigorous design approach resorting to advanced simulations for the response assessment. The first methodology evaluates the response through a prefixed probabilistic demand model, while the second approach considers the average response for a given hazard level only. The comparison allows to evaluate and quantify the effect of the seismic input uncertainty treatment on the system and damper performances

Scalable Distributed Approximation of Internal Measures for Clustering Evaluation

The most widely used internal measure for clustering evaluation is the silhouette coefficient, whose naive computation requires a quadratic number of distance calculations, which is clearly unfeasible for massive datasets. Surprisingly, there are no known general methods to efficiently approximate the silhouette coefficient of a clustering with rigorously provable high accuracy. In this paper, we present the first scalable algorithm to compute such a rigorous approximation for the evaluation of clusterings based on any metric distances. Our algorithm hinges on a Probability Proportional to Size (PPS) sampling scheme, and, for any fixed $\varepsilon, \delta \in (0,1)$, it approximates the silhouette coefficient within a mere additive error $O(\varepsilon)$ with probability $1-\delta$, using a very small number of distance calculations. We also prove that the algorithm can be adapted to obtain rigorous approximations of other internal measures of clustering quality, such as cohesion and separation. Importantly, we provide a distributed implementation of the algorithm using the MapReduce model, which runs in constant rounds and requires only sublinear local space at each worker, which makes our estimation approach applicable to big data scenarios. We perform an extensive experimental evaluation of our silhouette approximation algorithm, comparing its performance to a number of baseline heuristics on real and synthetic datasets. The experiments provide evidence that, unlike other heuristics, our estimation strategy not only provides tight theoretical guarantees but is also able to return highly accurate estimations while running in a fraction of the time required by the exact computation, and that its distributed implementation is highly scalable, thus enabling the computation of internal measures for very large datasets for which the exact computation is prohibitive.Comment: 16 pages, 4 tables, 1 figur

Thermoplastic Blends Based on Poly(Butylene Succinate- co -Adipate) and Different Collagen Hydrolysates from Tanning Industry: I—Processing and Thermo-mechanical Properties

AbstractIn this study, blends of a biodegradable thermoplastic polyester, poly (butylene succinate-co-adipate) (PBSA) with two different raw hydrolyzed collagens (HCs), derived from the tannery industry, were investigated in terms of processability, rheological, thermal and mechanical properties. HCs, obtained by alkaline (HCa) and enzymatic (HCe) hydrolysis of the solid wastes generated during the shaving of the tanned leather, were used in PBSA/HC blends, up to 20 wt% of HC, produced by melting extrusion and processed by injection molding. All the blends up to 20 wt% HCs resulted suitable for the injection molding obtaining flexible molded specimens with good tensile properties. The different secondary structure of the two HCs influenced the rheology, morphology and mechanical properties of the produced blends. In particular, HCa, due its higher content of oligopeptides and free amino-acids, showed a good compatibility with the polymeric matrix acting as a plasticizer with consequent reduction of melt viscosity with increasing its loading. The molded dog-bones specimens containing 20 wt% HCa showed a value of elongation at break of 810%. While, HCe, due its higher presence of b-sheet structures, behaved as organic filler, showing a poor interfacial interaction with PBSA with consequent decrease of the tensile properties with increasing its loading. The good processability and satisfactory mechanical properties obtained encourage the use of both investigated collagen hydrolysates in the production of thermoplastic blends and relative molded products for applications in agriculture and plant nurseries, such as pots or small containers with fertilizing properties, due the presence of HCs

Reliability-based optimal design of nonlinear viscous dampers for the seismic protection of structural systems

Viscous dampers are widely employed for enhancing the seismic performance of structural systems, and their design is often carried out using simplified approaches to account for the uncertainty in the seismic input. This paper introduces a novel and rigorous approach that allows to explicitly consider the variability of the intensity and characteristics of the seismic input in designing the optimal viscous constant and velocity exponent of the dampers based on performance-based criteria. The optimal solution permits controlling the probability of structural failure, while minimizing the damper cost, related to the sum of the damper forces. The solution to the optimization problem is efficiently sought via the constrained optimization by linear approximation (COBYLA) method, while Subset simulation together with auxiliary response method are employed for the performance assessment at each iteration of the optimization process. A 3-storey steel moment-resisting building frame is considered to illustrate the application of the proposed design methodology and to evaluate and compare the performances that can be achieved with different damper nonlinearity levels. Comparisons are also made with the results obtained by applying simplifying approaches, often employed in design practice, as those aiming to minimize the sum of the viscous damping constant and/or considering a single hazard level for the performance assessment

La tutela dei rom nel diritto svizzero ed italiano

Criminology, since long time has highlighted the preventive role of the education in the nomadic population; it is also true that it is hard to expect good results(considered as the variation of the criminal behaviours) in short times but this kind of support could surely help to reach positive outcomes in a longer lapse. On the other hand, the efforts to assure social-aid support to Rom people have had to run foul of their culture and to accept narrow social conventions. For these reasons the Authors believe that coercive impositions of different codes of behaviour could bring to a dangerous fight of cultures as much as serious xenophobic tendencies more than to an historically wished integration.Inficiata da ideologie e slogans politici, l’opinione pubblica, sia in Svizzera che in Italia, tende ad obliare le ricche peculiarità della cultura gitana. Per tal via, si dimenticano, oltretutto, le violente persecuzioni cui furono sottoposti gli zingari da parte degli Ordinamenti nazi-fascisti del Novecento. Del pari, svariati schieramenti partitici elvetici assai raramente risultano disponibili a menzionare l’orrida epurazione etnica agìta, sino al 1973, dalla Pro Juventute in danno dei Rom di etnia Jenisch residenti nella Confederazione. Con questo articolo non si vuole né negare né sminuire il carattere criminogeno intrinseco ai campi-nomadi stanziati ormai in tutta l’Europa occidentale. P.e., è innegabile la propensione zingara verso reati quali il furto ed il maltrattamento di minori per fini di accattonaggio. Ciononostante, l’odierna Criminologia ha giustamente posto in risalto anche il ruolo preventivo della scolarizzazione, pur se, come dimostrato dalle Politiche socio-pedagogiche in Italia, sono necessari decenni di paziente lavoro al fine di percepire fruttuosi mutamenti nella Weltangschauung delle minoranze semi-nomadi. In special modo, risulta arduo e complicato far accettare alla Civiltà romanès la figura di un/a insegnante alternativa alla mater familiae zingara, cui, da secoli, pertiene l’assolvimento di ogni compito educativo nei confronti della prole. In tale contesto, si ponga mente anche, e soprattutto, all’inesistenza, nella cultura rom, di una fase pedagogica e psico-fisiologica intermedia quale l’adolescenza. In realtà, questo articolo, nella parte finale, evidenzia che, sotto il profilo statistico prima ancora che processualistico, dev’essere superato lo stereotipo lombrosiano dello zingaro delinquente e puzzolente. Infatti, mentre la gioventù italiana si distingue sempre più sovente per la commissione di violenti delitti, viceversa, i minorenni rom sono assai raramente protagonisti di crimini efferati e/o connessi all’uso di sostanze tossico-voluttuarie. Anzi, la comunità gitana reca un ferreo codice d’onore limitante la gravità degli episodi delinquenziali. Per cui, sotto il profilo sociologico, rimane innegabile la molestia pubblica provocata dalle condizioni igienico-sanitarie dei campi nomadi. Tuttavia, sotto il profilo strettamente giuridico, la devianza nomade si sostanzia in fattispecie penali di calibro bagatellare e, ad ogni modo, non attinenti a delitti contro la persona. Senza dubbio, lo svolgimento di un’attività lavorativa non precaria costituirebbe un fattore di redenzione sociale. Eppure, nella mentalità zingara, il lavoro viene evitato non per via di un’indole abulica o pigra, bensì perché reputato alla stregua di una convenzione sociale mortificante la maggiore libertà conferita dal perenne e gaio viaggio delle carovane. Anche a livello spazio-temporale, l’uomo rom non tollera gli spazi chiusi e monotoni di una casa, di un’aula scolastica o di un centro di accoglienza. In buona sostanza, il semi-nomade percepisce se stesso come un inguaribile cosmopolita. Sicché, per tal via, è netto il rifiuto di interventi socio-assistenziali mortificanti un’autonomia senz’altro atipica, ma storicamente giustificata, avvalorata e financo nobilitata da secoli. Ovverosia, lo zingaro non contesta il moderno Welfare democratico-sociale, bensì egli lo rigetta per rispetto ad un bizzarro stile di vita atavico, nonché interiorizzato quale condotta non bisognosa di mutamento alcuno. Alla luce di quanto testé esposto, gli Autori non propongono né miracolosi progetti d’integrazione né speranzose conclusioni. Infatti, la Civiltà gitana, allo stato attuale, può soltanto essere rispettata dall’esterno. Viceversa, l’imposizione coattiva di stili di vita sedentari recherebbe ad un pericoloso scontro di culture, unitamente al risveglio di quelle medesime tendenze xenofobe già responsabili del genocidio nazi-fascista degli zingari

Cigarette tar yield and risk of upper digestive tract cancers: case-control studies from Italy and Switzerland

BACKGROUND: Tobacco smoking is one of the main risk factors for oral, pharyngeal and oesophageal cancers in developed countries. Information on the role of the tar yield of cigarettes in upper digestive tract carcinogenesis is sparse and needs to be updated because the tar yield of cigarettes has steadily decreased over the last few decades. PATIENTS AND METHODS: We analysed two case-control studies, from Italy and Switzerland, conducted between 1992 and 1999, involving 749 cases of oral and pharyngeal cancer and 1770 controls, and 395 cases of squamous-cell oesophageal carcinoma and 1066 matched controls. Odds ratios (ORs) were estimated by unconditional multiple logistic regression models, including terms for age, sex, study centre, education and alcohol consumption. RESULTS: Based on the brand of cigarettes smoked for the longest time, the multivariate ORs for current smokers compared with never smokers were 6.1 for &lt;20 mg and 9.8 for &gt;or=20 mg tar for oral and pharyngeal neoplasms, and 4.8 and 5.4 for oesophageal cancer, respectively. For the cigarette brand smoked in the previous six months, the ORs for &gt;or=10 mg compared with &lt;10 mg were 1.9 for cancer of the oral cavity and pharynx and 1.8 for oesophageal cancer, after allowance for number of cigarettes and duration of smoking. CONCLUSIONS: The present study confirms the direct relationship between the tar yield of cigarettes and upper digestive tract neoplasms, and provides innovative information on lower tar cigarettes, which imply reduced risks compared with higher tar ones. However, significant excess risks were observed even in the lower tar category, thus giving unequivocal indications for stopping smoking as a priority for prevention of upper digestive tract neoplasms. [authors]]]> https://serval.unil.ch/resource/serval:BIB_A7E274E177CA.P001/REF.pdf http://nbn-resolving.org/urn/resolver.pl?urn=urn:nbn:ch:serval-BIB_A7E274E177CA7 info:eu-repo/semantics/altIdentifier/urn/urn:nbn:ch:serval-BIB_A7E274E177CA7 info:eu-repo/semantics/publishedVersion info:eu-repo/semantics/openAccess Copying allowed only for non-profit organizations https://serval.unil.ch/disclaimer application/pdf oai:serval.unil.ch:BIB_A7E2FF85535D 2022-05-07T01:24:32Z openaire documents urnserval <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_A7E2FF85535D Indacaterol and glycopyrronium versus indacaterol on body plethysmography measurements in COPD-a randomised controlled study. info:doi:10.1186/s12931-016-0498-1 info:eu-repo/semantics/altIdentifier/doi/10.1186/s12931-016-0498-1 info:eu-repo/semantics/altIdentifier/pmid/28077140 Salomon, J. Stolz, D. Domenighetti, G. Frey, J.G. Turk, A.J. Azzola, A. Sigrist, T. Fitting, J.W. Schmidt, U. Geiser, T. Wild, C. Kostikas, K. Clemens, A. Brutsche, M. info:eu-repo/semantics/article article 2017-01-11 Respiratory research, vol. 18, no. 1, pp. 13 info:eu-repo/semantics/altIdentifier/eissn/1465-993X urn:issn:1465-9921 <![CDATA[Dual bronchodilator therapy is recommended for symptomatic patients with chronic obstructive pulmonary disease (COPD). There are limited data on effects of a combination of two long-acting bronchodilators on lung function including body plethysmography. This multicentre, randomised, double-blind, single-dose, cross-over, placebo-controlled study evaluated efficacy and safety of the free combination of indacaterol maleate (IND) and glycopyrronium bromide (GLY) versus IND alone on spirometric and body plethysmography parameters, including inspiratory capacity (IC), forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), total lung capacity (TLC) and airway resistance (Raw) in moderate-to-severe COPD patients. Seventy-eight patients with FEV1 % pred. (mean ± SD) 56 ± 13% were randomised. The combination of IND + GLY versus IND presented a numerically higher peak-IC (Δ = 0.076 L, 95% confidence interval [CI]: -0.010 - 0.161 L; p = 0.083), with a statistically significant difference in mean IC over 4 h (Δ = 0.054 L, 95%CI 0.022 - 0.086 L; p = 0.001). FEV1, FVC and Raw, but not TLC, were consistently significantly improved by IND + GLY compared to IND alone. Safety profiles of both treatments were comparable. The free combination of IND + GLY improved lung function parameters as evaluated by spirometry and body plethysmography, with a similar safety profile compared to IND alone. NCT01699685

The lack of star formation gradients in galaxy groups up to z~1.6

In the local Universe, galaxy properties show a strong dependence on environment. In cluster cores, early type galaxies dominate, whereas star-forming galaxies are more and more common in the outskirts. At higher redshifts and in somewhat less dense environments (e.g. galaxy groups), the situation is less clear. One open issue is that of whether and how the star formation rate (SFR) of galaxies in groups depends on the distance from the centre of mass. To shed light on this topic, we have built a sample of X-ray selected galaxy groups at 0<z<1.6 in various blank fields (ECDFS, COSMOS, GOODS). We use a sample of spectroscopically confirmed group members with stellar mass M >10^10.3 M_sun in order to have a high spectroscopic completeness. As we use only spectroscopic redshifts, our results are not affected by uncertainties due to projection effects. We use several SFR indicators to link the star formation (SF) activity to the galaxy environment. Taking advantage of the extremely deep mid-infrared Spitzer MIPS and far-infrared Herschel PACS observations, we have an accurate, broad-band measure of the SFR for the bulk of the star-forming galaxies. We use multi-wavelength SED fitting techniques to estimate the stellar masses of all objects and the SFR of the MIPS and PACS undetected galaxies. We analyse the dependence of the SF activity, stellar mass and specific SFR on the group-centric distance, up to z~1.6, for the first time. We do not find any correlation between the mean SFR and group-centric distance at any redshift. We do not observe any strong mass segregation either, in agreement with predictions from simulations. Our results suggest that either groups have a much smaller spread in accretion times with respect to the clusters and that the relaxation time is longer than the group crossing time.Comment: Accepted for publication in MNRA

About Time: Master Scheduling and Equity

Master schedules are used to structure time, people, resources, and space within a school. This report provides school and district leaders advice about how to use the master schedule to advance equity in their communities. It illuminates ways the schedule can both undermine and advance equity and provides a framework to help schools and districts pivot from technical to strategic scheduling to expand access and opportunity for all student

3D speckle tracking for evaluation of dilative ascending aorta biomechanics: sensitive markers for ascending aorta longitudinal strain predict aortic root dilation rate

ascending aortic aneurysm is a predisposing condition for rupture and a risk factor for dissection. In autopsy studies, the prevalence of aortic dissection ranges from 0.2% to 0.8%, whereas in most population-based studies, the incidence of aortic dissection ranges from 0.61 to 7.2/100 000 persons. the surgical option, or endovascular treatment, remains the only effective treatment. Very often, the aorta ruptures at echocardiographic or CT values lower than those indicated by the guidelines for performing an operation. therefore, research efforts are aimed at discovering new markers for earlier diagnoses to intervene preventively on dilated aortas at risk of rupture. the protocol of our study involves the evaluation of the longitudinal deformation of the dilated ascending aortas that must undergo surgery and their histological data. the objective would be to identify whether the altered distensibility of the aorta upon echocardiographic control is confirmed by histological data in terms of stiffness or other pathophysiological aspects. this would allow the identification of new markers for the early diagnosis of aortas at increased risk of rupture, even if they do not reach the diameters indicated by the guidelines. patients over 18 years of age, diagnosed with ascending aortic aneurysm with simultaneous aortic valve disease, will be considered for the study. they will be analyzed by intraoperative transesophageal echocardiography with speckle tracking echocardiography during five heart beats using 2D and 3D images. the study will define the 3-segment ascending aorta (aortic ring, aortic root and proximal ascending aorta) and the four quadrants of the ascending aorta (internal curvature, anterior wall, external curvature and posterior wall). a short-axis view at the level of maximum dilation, a long-axis view of the ascending aorta and a histological examination of the aorta. data will be collected on demographics, clinical data, screening, family history, adherence to study methods, intraoperative details, intraoperative histology and the type of surgery performed. the results of our study will be published in a peer-reviewed journal, and the abstracts will be presented at national or international conferences