Simulation and control problems in elastic robots

Computational issues associated with modeling and control of robots with revolute joints and elastic arms are considered. A manipulator with one arm and pinned at one end is considered to investigate various aspects of the modeling procedure and the model, and the effect of coupling between the rigid-body and the elastic motions. The rigid-body motion of a manipulator arm is described by means of a reference frame attached to the shadow beam, and the linear elastic operator denoting flexibility is defined with respect to this reference frame. The small elastic motion assumption coupled with the method of assumed modes is used to model the elasticity in the arm. It is shown that only terms up to quadratic in these model amplitudes need to be retained. An important aspect of the coupling between the rigid-body and the elastic motion is the centrifugal stiffening effect. This effect stiffens the elastic structure, as to be expected on physical grounds, gives rise to a time-varying inertia term for the rigid-body motion, and, in general, results in an effective inertia term smaller than the rigid-body inertia term. Simulation results are presented for an elastic beam pinned at one end and free at the other, and rotating in a horizontal plane, and control issues such as the order of the model, number of sensors, and modal extraction are examined within this context

Bankacılık belge merkezi

Taha Toros Arşivi, Dosya No: 36-Ethem İbrahim-İsmail Galip-Osman Salih-Sedat Hakkı-Fethi-Edhem Eldemİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033

Elastic moduli approximation of higher symmetry for the acoustical properties of an anisotropic material

The issue of how to define and determine an optimal acoustical fit to a set of anisotropic elastic constants is addressed. The optimal moduli are defined as those which minimize the mean squared difference in the acoustical tensors between the given moduli and all possible moduli of a chosen higher material symmetry. The solution is shown to be identical to minimizing a Euclidean distance function, or equivalently, projecting the tensor of elastic stiffness onto the appropriate symmetry. This has implications for how to best select anisotropic constants to acoustically model complex materials.Comment: 20 page

Actuator Constrained Trajectory Generation and Control for Variable-Pitch Quadrotors

Control and trajectory generation algorithms for a quadrotor helicopter with variable-pitch propellers are presented. The control law is not based on near-hover assumptions, allowing for large attitude deviations from hover. The trajectory generation algorithm ts a time-parametrized polynomial through any number of way points in R3, with a closed-form solution if the corresponding way point arrival times are known a priori. When time is not specifi ed, an algorithm for fi nding minimum-time paths subject to hardware actuator saturation limitations is presented. Attitude-specifi c constraints are easily embedded in the polynomial path formulation, allowing for aerobatic maneuvers to be performed using a single controller and trajectory generation algorithm. Experimental results on a variable pitch quadrotor demonstrate the control design and example trajectories.National Science Foundation (U.S.) (Graduate Research Fellowship under Grant No. 0645960

The Guilty Pleasure of Watching Like Big Brother: Privacy Attitudes, Voyeurism & Reality Programs

Media commentators have offered different explanations for the rising popularity of reality television. One frequently cited hypothesis is that the rising popularity of reality programs can be attributed to their ability to accommodate television viewers\u27 voyeuristic needs. It has also been suggested that the voyeuristic appeal of reality programs often comes at the price of privacy and dignity of their participants. However, existing literature on audience behavior and reality programming only tangentially addresses the question of how television viewers\u27 voyeuristic orientations and their attitudes about value of privacy factor into the choices they make about consuming reality television. The primary purpose of this dissertation thesis is to fill this void by investigating these two potential drivers of reality television consumption. In order to do so, this project first utilized a crossectional survey, which asked respondents to report the frequency with which they watched 18 reality programs broadcast on major national networks. Participants also responded to a battery of questions regarding their voyeuristic orientation, attitudes about privacy, and their tendency to use television for voyeurism. In addition, a content analysis of reality programs was used to weight the findings from the survey. The findings from this study suggest that voyeurism, as a psychological orientation, is positively related to consumption of reality programs and that this relationship between voyeurism and exposure to reality programming is mediated by a tendency to use television to satisfy voyeurism. With respect to the relationship between privacy attitudes and consumption of reality programming, the findings indicate that one consistent predictor of avoidance of reality programs is the belief that one should be concerned about the privacy of other individuals even if they fail to protect their own privacy. Finally, comparison of unweighted reality television exposure measure and exposure measures weighted by content analysis results revealed that scenes taking place in private or semi-private settings, scenes containing nudity and scenes containing gossip contributed to the voyeuristic appeal of reality programs

Superconductivity in type II layered Weyl semi-metals

Novel quasi two dimensional typically layered semimetals offer a unique opportunity to control the density and even the topology of the electronic matter. In intercalated MoTe2 type II Weyl semimetal the tilt of the dispersion relation cones is so large that topologically of the Fermi surface is distinct from a more conventional type I. Superconductivity observed recently in this compound [Zhang et al, 2D Materials 9, 045027 (2022)] demonstrated two puzzling phenomena: the gate voltage has no impact on critical temperature, Tc, in wide range of density, while it is very sensitive to the interlayer distance. The phonon theory of pairing in a layered Weyl material including the effects of Coulomb repulsion is constructed and explains the above two features in MoTe2.The first feature turns out to be a general one for any type II topological material, while the second reflects properties of the intercalated materials affecting the Coulomb screening

The educational philosophy of Yad Vashem

Holokaust se obično predstavlja putem tradicionalnog istorijskog istraživanja, analiziranjem različitih vrsta pisanih dokumenata, svedočenja i fotografija, u cilju boljeg razumevanja istorijskog procesa „konačnog rešenja“. Ovakva vrsta predstavljanja pruža opsežnu sliku političkih odluka koje su počinioci donosili, ali slika jevrejske žrtve ostaje nejasna pod senkom pepela iz gasnih komora. Jevrejin nema lice, prošlost, porodicu, nije ništa drugo do bespomoćni predmet nacističke politike, deo jedne ogromne planine spaljenih skeleta, matematički zbir od šest miliona izgubljenih života. Ovakav način predstavljanja osnažuje nacističku percepciju Jevreja, koja ne uništava samo njivova tela, već i njihovo sećanje, jer niko ne može da oseća iskrenu empatiju prema brojkama. Trenutna reakcija na te traumatične zastrašujuće slike je odbijanje ili poricanje. Ovakvo stanovište neminovno upućuje na tvrdnju da se Holokaust ne može razumeti kao deo istorijskih pojava, i da se Hitler opisuje kao ludak, bolesnik! Takav pristup je posebno opasan, jer oslobađa počinioce odgovornosti. Iz tog razloga moramo napraviti razliku između uloge istoričara i uloge nastavnika. Istorija pripoveda priču, a obrazovanje daje značenje. Tema Holokausta je deo nastavnog plana i programa u srednjoj školi i predstavlja važan deo završnog ispita iz istorije. Ali učenje činjenica napamet ne znači stvarno razumevanje moralnog značaja i posledica ovog pitanja. Na osnovu pedagoškog iskustva Izraela, dugom više od pedeset godina, došli smo do zaključka da nam je potreban senzitivniji i efikasniji način podučavanja o Holokaustu. Ova filozofija kreirana je u Jad Vašemu, najvećem obrazovnom centru o Holokaustu u Izraelu. Ideja se zasniva na činjenici da je Holokaust važan deo ljudske istorije, jer su ljudska bića istrebljivala druga ljudska bića zbog neljudske ideologije ubijanja koju su stvorili ljudi, koji su tada postali nehumani počinioci i ubice. Osim toga, imamo obavezu da sprečimo da slika jevrejske žrtve ostane bez lica i iščezne iza brojeva. Prema ovom pristupu, mi kao nastavnici moramo da podučavamo o Holokaustu kroz ljudsku percepciju, baveći se moralnim dilemama sa kojima su se ljudi suočavali tokom Holokausta. Pokušavamo da razumemo te užasne dileme sa kojima su morali da se suoče, a za koje kažemo da su „izbori bez prave mogućnosti izbora”, a koji su se pred njih postavljali iz dana u dan. Podučavati o Holokaustu znači učiti o žrtvama, o počiniocima, posmatračima i spasiocima sa ličnog stanovišta.The Holocaust is usually presented through traditional historical research, analyzing various types of written documents, testimonies and photographs, to better understand the historical process of the "Final Solution". This type of presentation provides a comprehensive picture of the political decisions made by the perpetrators, but the picture of the Jewish victim remains unclear under the shadow of the ashes from the gas chambers. The Jew has no face, no past, no family, he is nothing more than a helpless object of Nazi policy, part of a huge mountain of burned skeletons, the mathematical sum of six million lost lives. This way of presentation reinforces the Nazi perception of Jews, which not only destroys their bodies but also their memory because no one can feel sincere empathy towards the numbers. The immediate reaction to those traumatic frightening images is rejection or denial. This point of view inevitably leads to the claim that the Holocaust cannot be understood as a part of a historical phenomenon and that Hitler is described as a madman, a sick person! Such an approach is particularly dangerous because it frees the perpetrators from responsibility. For this reason, we must distinguish between the role of the historian and the role of the teacher. History tells the story and education gives meaning. The topic of the Holocaust is part of the high school curriculum and is an important part of the final history exam. However, memorizing the facts does not mean understanding the moral significance and consequences of the issue. Based on the pedagogic experience of Israel, spanning more than fifty years, we concluded that we need a more sensitive and effective way of teaching about the Holocaust. This philosophy was created at Yad Vashem, the largest Holocaust education centre in Israel. The idea is based on the fact that the Holocaust is an important part of human history because human beings exterminated other human beings because of an inhuman ideology of killing created by humans, who then became inhumane perpetrators and murderers. In addition, we should prevent the image of the Jewish victim from remaining faceless and disappearing behind the numbers. According to this approach, we as teachers must teach about the Holocaust through human perception, dealing with the moral dilemmas that people faced during the Holocaust. We are trying to understand the terrible dilemmas they had to face, which we say are "choices without real choice", and which were presented to them day after day. Teaching about the Holocaust means learning about the victims, the perpetrators, the bystanders and the rescuers from a personal point of view.Originalni tekst na engleskom jeziku objavljen je u "Topola: časopis JU Spomen-područja Donja Gradina", god. 1, br. 1, (2015), str. 227-236 i može se preuzeti preko linka (The original text in English was published in "Topola: magazine JU Spomen-područja Donja Gradina", vol. 1, no. 1, (2015), p. 227-236 and can be downloaded via the link) [https://jevrejskadigitalnabiblioteka.rs/handle/123456789/2707

I hid the children's death from my mother

U seriji od pet knjiga "Mi smo preživeli: Jevreji o Holokaustu" od kojih su tri prevedene na engleski jezik, sakupljena su svedočenja malobrojnih preživelih članova jevrejske zajednice o vremenu Drugog svetskog rata. Osobenost prilika u kojima se zateklo celokupno stanovništvo Kraljevine Jugoslavije ogleda se u činjenici da je tu državu, početkom rata, okupiralo pet zavojevača: Nemačka, Italija, Bugarska, Mađarska, Albanija i fašistička satelitska tvorevina, tzv. Nezavisna država Hrvatska. Te okolnosti su uslovile i različite načine preživljavanja i spašavanja Jevreja sa ovih prostora. Jevrejski istorijski muzej Saveza jevrejskih opština Jugoslavije/Srbije objavio je ove knjige uz pomoć donacija i uz volonterski rad redakcije u kojoj je sedam od devet članova preživelo Holokaust. One čine izuzetnu kolekciju tragičnih i dramatičnih iskustava o jedinstvenom izboru – borbi za život, dostojanstvo i slobodu u partizanima; o koncentracionim logorima, o izbegličkom životu pod stalnom pretnjom, o pomoći i prijateljstvima. One su i dobra podloga za istraživanje Holokausta i istorije Jevreja sa tla bivše Jugoslavije. Svako svedočenje je obogaćeno nizom fotografija i zajedno sa tekstom čine jedinstveni dokumentacioni materijal. Kako je stradanje Jevreja na tlu bivše Jugoslavije slabo poznato široj publici, ove knjige imaju zadatak da ispune taj prostor. One tako postaju spomenik za sve stradale čija se mnogobrojna imena nalaze samo u sećanjima. Jedno od tih sećanja je "Majci sam krila istinu o pogibiji dece" Sonje Baruh.In five books, "We Survived: Yugoslav Jews on the Holocaust" (three of them translated into English), the testimonies of a small number of surviving members of the Jewish community about World War II were collected. The peculiarity of the circumstances in which the entire population of the Kingdom of Yugoslavia was found is reflected in the fact that at the beginning of the war, the country was occupied by five invaders: Germany, Italy, Bulgaria, Hungary, Albania and the fascist satellite formation, the so-called. The Independent State of Croatia. These circumstances also led to different ways of surviving and rescuing Jews from these areas. The Jewish Historical Museum of the Federation of Jewish Communities of Yugoslavia / Serbia published these books with help of donations and volunteer work of the editorial board in which seven of nine members survived the Holocaust. These books are an extraordinary collection of tragic and dramatic experiences about unique choices - the struggle for life, dignity, and freedom in partisans; about concentration camps, refugee life under constant threat, and about help and friendships. They are also a good basis for exploring the Holocaust and the history of Jews from the former Yugoslavia. Each testimony is enriched with a series of photographs and together with the text, they make unique documentation material. As the suffering of Jews on the territory of the former Yugoslavia is poorly known to the general public, these books have the task of filling that space. They thus become a memorial for all the victims whose many names are found only in memory. One of those memories is "Majci sam krila istinu o pogibiji dece" (I hid the children's death from my mother) by Sonja Baruh

Estado de la investigación y bibliografía anotada de la obra literaria de Laura Papo «Bohoreta»

This article is a survey of the history and the state of the art of the literary opus of Laura Papo “Bohoreta,” the first Judeo-Spanish female dramatist. It offers, here, for the first time, a definitive list of all her known and preserved original writings (theater plays, poems, short stories, nouvelles and essays), most of them still unpublished, as well as of her literary translations and recopilations of Sephardic folklore.El articulo trata de realizar una catalogación de la obra literaria de Laura Papo «Bohoreta », la primera dramaturga femenina de la literatura sefardí. Se ofrece aquí, por primera vez, una lista de todos sus escritos originales (piezas dramáticas, poemas, cuentos breves, novelas y ensayos) conocidos y preservados (en gran parte, inéditos aún). A ello se añade un estado de la cuestión de las traducciones literarias, así como de las recopilaciones de folclore sefardí que ella realizó