Search results for "aid"
showing 10 items of 3031 documents
Optimization of structures with unrestricted dynamic shakedown constraints
2015
The unrestricted dynamic shakedown theory is here utilized with the aim to formulate different optimal design problems for structures mainly subjected to seismic loads. In particular, reference is made to plane frame structures constituted by elastic perfectly plastic material subjected to load combinations characterized by the presence of simultaneous fixed and seismic actions. The design problems, formulated on the ground of a statical approach, are devoted to structures with and without seismic protection devices, with special emphasis to seismic isolators. For the proposed design problem formulations different constraints are utilized; actually, for structures without protection devices…
Computational methods for optimal shakedown design of FE structures
1998
The paper concerns the optimal shakedown design of structures discretized by elastic perfectly plastic finite elements. The design problem is formulated in four alternative versions, i.e. as the search for the minimum volume design whose shakedown limit load multiplier is assigned or as the search for the maximum shakedown limit load multiplier design whose volume is assigned; both problems are approached on the grounds of the shakedown lower bound and upper bound theorems. Correspondingly four computational methods, one for each original problem, are presented. These methods consist in solving iteratively new problems which are simpler than the original ones, but expressed in such a way th…
Optimal shakedown design of beam structures
1994
The optimal design of plane beam structures made of elastic perfectly plastic material is studied according to the shakedown criterion. The design problem is formulated by means of a statical approach on the grounds of the shakedown lower bound theorem, and by means of a kinematical approach on the grounds of the shakedown upper bound theorem. In both cases two different types of design problems are formulated: one searches for the minimum volume design whose shakedown limit load is assigned; the other searches for the design of the assigned volume whose shakedown limit load is maximum. The optimality conditions of the four problems above are found by the use of a variational approach; such…
Thermal buckling optimization of composite laminates by evolution strategies
2000
Abstract Thermal buckling optimization of laminated composite plates subject to a temperature rise is presented in this paper. Aerospace structures require such components that are able to withstand the external environment loads without loss of stability. The discrete optimal design problem, formulated under strain and ply contiguity constraints is solved using evolution strategies, a guided random-search method. Two different constraint handling methods are investigated and compared: the disregarding infeasible solutions and the classical penalty function approach. The results are also compared with an exact enumerative study conducted on the problem, showing the effectiveness and perform…
Joint Power Allocation and Link Selection for Multi-Carrier Buffer Aided Relay Network
2019
In this paper, we present a joint power allocation and adaptive link selection protocol for an orthogonal frequency division multiplexing (OFDM)-based network consists of one source node i.e., base station (BS), one destination node i.e., (MU) and a buffer aided decode and forward (DF) relay node. Our objective is to maximize the average throughput of the system via power loading over different subcarriers at source and relay nodes. A separate power budget is assumed at each transmitting node to make the system more practical. In order to form our solution more tractable, a decomposition framework is implemented to solve the mixed integer optimization problem. Further, less complex suboptim…
Sanarytmien vaikutus kuultujen rytmien oppimiseen
2015
Tutkielmani kohdistuu sanarytmien käyttöön rytmiikan oppimisessa. Kirjallisuuskatsauksessa käsitellään rytmiikan oppimista laajemminkin, koska sanarytmit ovat osa monimuotoista musiikillisen oppimisen kokonaisuutta. Musiikillinen ilmaisu on kehon ja mielen yhteistyötä: kehon avulla toteutetaan mielessä muodostuvia musiikillisia mielikuvia. Sanarytmit ovat oiva väline rytmisten mielikuvien kehittämiseen, ja hyvä koordinaatiokyky on edellytys onnistuneelle soittosuoritukselle. Tutkimukseni empiirinen aineisto liittyy sanarytmeihin. Tutkimukseni teoreettinen tausta muodostuu rytmiopista, rytmiikan oppimisen lähtökohdista ja didaktisista sovelluksista. Oppimisen lähtökohtina tar…
Services à la personne et services d’aide à domicile au Québec : difficultés des conditions de travail et de la conciliation travail-vie personnelle.
2017
International audience
La incidencia del salario mínimo interprofesional en sectores de bajos salarios
2012
El salario mínimo es un tema que ha vuelto a cobrar actualidad. La mayoría de los análisis que se realizan al respecto se centran en determinar si su nivel tiene algún tipo de incidencia sobre el empleo. No obstante, son escasos los trabajos que abordan si efectivamente el salario mínimo cumple con su objetivo básico: mejorar las rentas de los perceptores de bajos salarios. En este trabajo abordamos precisamente esta cuestión. Para ello se analiza la evolución de los salarios en la negociación colectiva en tres sectores considerados de bajos salarios (comercio al por menor, hostelería y limpieza de locales y edificios), centrándonos en los puestos inferiores de la escala salarial. The minim…
Emotional competence at work
2020
PurposeThe study investigated emotional competence at work and elaborated emotional competence in relation to sociocultural aspects of emotions at work.Design/methodology/approachEmotional competence at work was explored via interviews, surveys and observations. The study was conducted over one year, during which an emotion-training intervention was conducted within a medium-sized company, operating in the healthcare sector.FindingsThe study shed light on emotional competence at work, identifying three domains: individual emotional competence, emotional competence within interactions and emotional competence embedded in workplace practices.Research limitations/implicationsThis study was con…
Accuracy of 4 digital scanning systems on prepared teeth digitally isolated from a complete dental arch
2018
Abstract Statement of problem The accuracy of digital scanners is acceptable for scanning a complete dental arch. However, whether that accuracy is sufficient for only 1 tooth within the dental scan of a complete dental arch is unclear. Purpose The purpose of this in vitro study was to evaluate and compare the accuracy of 4 intraoral scanners on a complete dental arch and on prepared teeth digitally isolated from the digital scan in terms of trueness and precision. Material and methods A model of a complete dental arch with tooth preparations was scanned 40 times with each of the 4 digital scanners. Their accuracy was evaluated by using 3-dimensional (3D) software to compare the test models…