86 research outputs found
Simultaneous Identification of Moving Vehicles and Bridge Damages Considering Road Rough Surface
A method for the simultaneous identification of moving vehicles and the damages of the supporting structure from measured responses is presented. A two-axle vehicle model with two degrees of freedom (DOF) is adopted. The extent of the damage and the vehicle parameters were chosen as the optimisation variables, which allow ill conditioning to be avoided and decrease the number of sensors required. The identification is performed by minimising the distance between the measured responses and the computed responses to given optimisation variables. The virtual distortion method (VDM) was used, such that the response of the damaged structure can be computed from comparison with the intact structure subjected to the same vehicle excitation and to the response-coupled virtual distortions. These are related to the optimisation variables by the system impulse response matrix and are expressed by a linear system, which allowed both types of optimisation variables to be treated in a unified way. The numerical cost is reduced by using a moving influence matrix. The adjoint variable method is used for fast sensitivity analysis. A three-span bridge numerical example is presented, where the identification was verified with 5% root mean square (RMS) measurement, and model, error whilst also considering the surface roughness of the road
Geo-questionnaire in urban planning – preliminary results of the experimental application in Poland
Changes in the attitude of local authorities towards the public participation in the decision making processes have prompted development of new methods of such involvement. As far as the urban planning is concerned, of particular potential is the so-called Public Participation Geographic Information Systems (PPGIS). One of the tools used for the purpose is a geo-questionnaire, combining the benefits of a standard questionnaire and a map, which permits collecting information on particular sites and on the respondents’ ideas on localisation of new objects and functionalities.Within the project “Geoportal supporting public participation in urban planning”, in the years 2015–2016, a study was undertaken to explore the effectiveness and usefulness of the geo-questionnaire. Five pilot studies were performed in the Poznań and Łódź agglomerations. The geo-questionnaires concerned the local spatial management plan in Rokietnica (Poznań agglomeration), landscape protection in Łódź, conception of the transportation system development in Łódź, conception of urban design of the Łazarski Market in Poznań, and the Map of Local Needs in the city center of Poznań. The aim of the study was to present the preliminary results of the initial implementations of geo-questionnaire developed within the project Geoportal supporting public participation in urban planning. The applications of geo-questionnaire have been analysed taking into account the characteristics of implementation areas, characteristics of users, the effectiveness of recruitment methods and opinions about the tool from two points of view: the respondents and the recipients of results
Kompetencje pracownicze w firmach branży TSL wspierających działania proekologiczne
Firmy z branży TSL powoli angażują się w działania proekologiczne. W ich ofertach pracy powinno znaleźć się nawiązanie do zielonych kompetencji. Na przykładzie 207 ofert pracy dla kierowcy i magazyniera zamieszczonych na portalach internetowych prześledzono rodzaj poszukiwanych kompetencji pracowniczych. Zauważono, że firmy nie są jeszcze gotowe, aby uznać działania proekologiczne za element przewagi konkurencyjnej, gdyż ich oferty pracy z reguły nie odwoływały się do zielonych kompetencji
Inhibitory hydroksylazy prolinowej czynników indukowanych niedotlenieniem (HIF-PHI) — przełom w leczeniu niedokrwistości u chorych z przewlekłą chorobą nerek?
Anemia is the common complication of chronickidney disease (CKD). Insufficient secretion oferythropoietin by damaged kidneys and disordersof iron management (including increased hepcidinconcentration) play a major role in it’s pathophysiology.Classical treatment of anemia in patients withCKD bases on the correction of iron deficienciesand administration of erythropoiesis stimulatingfactors (ESAs) — analogues of human erythropoietin.In 1992 Semenze and Wang for the first timediscovered the molecule activating gene expressionfor erythropoietin — the hypoxia-induced HIF-1 transcriptionfactor, which paved the way for researchinto new ways of treating anemia in patients withCKD. In the article the current state of knowledge regardingthe mechanism of action and the clinical usageof new drugs — hypoxia-inducible factor prolylhydroxylase inhibitors (HIF-PHI) — in the treatmentof anemia in patients with CKD was described.Jednym z częstych powikłań przewlekłej choroby nerek (PChN) jest niedokrwistość, w której patofizjologii główną rolę odgrywają niedostateczne wydzielanie erytropoetyny przez uszkodzone nerki, jak również zaburzenia gospodarki żelazem (w tym zwiększenie stężenia hepcydyny). Klasyczne leczenie niedokrwistości u chorych z PChN opiera się na wyrównywaniu niedoborów żelaza oraz podawaniu czynników stymulujących erytropoezę (ESA), będących analogami ludzkiej erytropoetyny. Odkrycie przez Semenzę i Wanga w 1992 roku cząsteczki aktywującej ekspresję genu dla erytropoetyny — indukowanego niedotlenieniem czynnika transkrypcyjnego HIF-1 — otworzyło drogę do badań nad nowymi sposobami terapii niedokrwistości u tych chorych. W artykule opisano obecny stan wiedzy na temat mechanizmu działania i możliwości klinicznego zastosowania nowych leków — inhibitorów hydroksylazy prolilowej czynników indukowanych niedotlenieniem (HIF-PHI) — w leczeniu niedokrwistości u chorych z PChN
Public Participation GIS for sustainable urban mobility planning: methods, applications and challenges
Sustainable mobility planning is a new approach to planning, and as such it requires new methods of public participation, data collection and data aggregation. In the article we present an overview of Public Participation GIS (PPGIS) methods with potential use in sustainable urban mobility planning. We present the methods using examples from two recent case studies conducted in Polish cities of Poznań and Łodź. Sustainable urban mobility planning is a cyclical process, and each stage has different data and participatory requirements. Consequently, we situate the PPGIS methods in appropriate stages of planning, based on potential benefits they may bring into the planning process. We discuss key issues related to participant recruitment and provide guidelines for planners interested in implementing methods presented in the paper. The article outlines future research directions stressing the need for systematic case study evaluation
Structural Health Monitoring Based on Combined Structural Global and Local Frequencies
This paper presents a parameter estimation method for Structural Health Monitoring based on the combined measured structural global frequencies and structural local frequencies. First, the global test is experimented to obtain the low order modes which can reflect the global information of the structure. Secondly, the mass is added on the member of structure to increase the local dynamic characteristic and to make the member have local primary frequency, which belongs to structural local frequency and is sensitive to local parameters. Then the parameters of the structure can be optimized accurately using the combined structural global frequencies and structural local frequencies. The effectiveness and accuracy of the proposed method are verified by the experiment of a space truss
Nonparametric identification of added masses in frequency domain: a numerical study
Abstract This paper presents a theoretical derivation and reports on a numerical verification of a model-free method for identification of added masses in truss structures. No parametric numerical model of the monitored structure is required, so that there is no need for initial model updating and fine tuning. This is a continuation and an improvement of a previous research that resulted in a time-domain identification method, which was tested to be accurate but very time-consuming. A general methodology is briefly introduced, including the inverse problem, and a numerical verification is reported. The aim of the numerical study is to test the accuracy of the proposed method and its sensitivity to various parameters (such as simulated measurement noise and decay rate of the exponential FFT window) in a numerically controlled environment. The verification uses a finite element model of the same real structure that was tested with the time-domain version of the approach. A natural further step is a lab verification based on experimental data
Occupational risks for SARS-CoV-2 infection : the Polish experience
The disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), termed COVID-19, is asymptomatic or mild in
most cases. These patients do not need treatment in hospital and can be isolated at home. To date, most studies have been conducted among inpatients
with severe COVID-19. In this study, the authors surveyed patients with mild COVID-19 who remained in home isolation, and analyzed the sources
and occupational risk factors for SARS-CoV-2 infections. Material and Methods: This cross-sectional study was carried out on April 17-18, 2020,
among patients infected with SARS-CoV-2 who remained in home isolation in Poland. Data were acquired through a structured interview that included questions about the isolation course, symptoms, comorbidities, infection source, household characteristics, occupation, and workplace. Data
were presented with descriptive statistics. Results: Of the 4878 patients in home isolation, the authors were able to contact 3313. Of them, 1191 patients declined their invitation, and 2122 agreed to take part. The median age of the patients included in the study was 50 years; 59% were female.
Most patients (92%) had not been abroad before the infection. More than half (55%) knew how they became infected; of them, 75% became infected
at work. Of all patients, 70% were occupationally active. Nearly half of the occupationally active patients (48%) worked in healthcare, 3% worked in
public administration or defense, 3% worked in transportation, and 2% worked in education. Sixty-five percent of the occupationally active patients
worked in companies with >100 employees. Conclusions: Most of the patients with COVID-19 in home isolation in Poland were occupationally
active, wherein the majority of people who were aware of the source of SARS-CoV-2 infection worked in healthcare. As most of the infected patients
worked in companies with >100 employees, which is not a Polish employment pattern, the authors expect that smaller companies may have a lower
risk of SARS-CoV-2 infections
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