PDF superior On the exhaustiveness of truncation and dropping strategies in many-to-many matching markets

On the exhaustiveness of truncation and dropping strategies in many-to-many matching markets

On the exhaustiveness of truncation and dropping strategies in many-to-many matching markets

In manyto–one matching markets, the set of stable matchings coincides with the core. In addition, ruling out blocking pairs is sufficient for ruling out blocking coalitions that involve more than two agents. This is not true in manytomany matching markets. Not only might the set of stable matchings be different from the core, but also there might be stable matchings that can be blocked by coalitions of more than two agents. Sotomayor (1999b) studied the stronger concept of setwise stability and showed that in the manytomany model the set of stable matchings, the core, and the set of setwise stable matchings do not coincide. However, potential larger blocking coalitions in complex real–life settings might have more difficulties to organize themselves. In fact, Roth (1991, page 422) suggested that for manytomany markets such as the British entry–level medical labor markets, stability is still of primary importance.
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18 Lee mas

On the Exhaustiveness of Truncation and Dropping Strategies in Many-to-Many Matching Markets

On the Exhaustiveness of Truncation and Dropping Strategies in Many-to-Many Matching Markets

Even though there is evidence that clearinghouses that employ stable mechanisms often perform better than those that employ unstable mechanisms, 4 no stable mechanism is immune to preference manipulation (Dubins and Freedman, 1981, and Roth, 1982). This fact immediately triggers a question: What types of strategies should a strategic agent consider? In the present paper, we focus on two types of “simple” preference manipulations that have been reported and studied in empirical and theoretical work. The first class of preference manipulations is that of truncation strategies (Roth and Vande Vate, 1991). A truncation strategy is a list that is obtained from an agent’s true preference list by removing a tail of its least preferred potential partners. 5 The second class of preference manipulations consists of dropping strategies (Kojima and Pathak, 2009). A dropping strategy is a list that is obtained from an agent’s true preference list by removing potential partners (i.e., no reshuffling). Obviously, each truncation strategy is also a dropping strategy. Roth and Rothblum (1999) studied the firm–optimal stable mechanism in the manyto–one model. They showed that if a worker’s incomplete information is completely symmetric, then it might only gain by reporting a truncation strategy. Ehlers (2008) obtained a similar result for all so–called priority and linear programming mechanisms. Coles (2009) constructively examined truncation strategies in the one–to–one model. He established that also in asymmetric incomplete information settings workers can truncate lists with little risk of ending up unmatched, but with the potential to see large gains. Ma (2010) studied truncation strategies and the equilibrium outcomes induced by the workers–optimal mechanism in one–to– one and manyto–one matching markets. For one–to–one, he found that if in equilibrium each firm uses a truncation strategy, then the equilibrium outcome is the firms–optimal matching. For manyto–one, he found that if in equilibrium each firm uses a truncation strategy, then the equilibrium outcome is either the firms–optimal matching or an unstable matching with respect to the true preferences.
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20 Lee mas

Equilibria under Deferred Acceptance: Dropping Strategies, Filled Positions, and Welfare

Equilibria under Deferred Acceptance: Dropping Strategies, Filled Positions, and Welfare

Most real-life applications of the SOSM are instances of manyto–one markets. For this reason we aim to determine if the extraordinary features of the equilibria in the one–to–one setting carry over to the manyto–one setting. A key difference with the one–to–one setting was established in Roth and Sotomayor (1990, Corollary 5.17) through an example of a manyto–one market with an unstable equilibrium outcome. We show that any stable matching is still the induced outcome of some equilibrium (Proposition 1). Therefore, the set of stable matchings is a (possibly strict) subset of the set of equilibrium outcomes. The fact that the two sets do not necessarily coincide does not rule out a priori the possibility that the set of equilibrium outcomes satisfies important structural properties as those described for the one–to–one setting. But unfortunately we show that this is not the case. Our three results on the (absence of) structure of the set of equilibrium outcomes can be summarized as follows.
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Lay Public Mental Models of Nuclear or Radiological Emergency Situations. Findings from Spain.

Lay Public Mental Models of Nuclear or Radiological Emergency Situations. Findings from Spain.

Furthermore, research on public responses during real nuclear emergencies has been examined on previous research. The reactions and responses of the public during and after the Three Mile Island (TMI) accident have been studied by various authors. Flynn (1979) survey studied the areas of evacuation behaviour, information processing, short-term accident effects, continuing effects of the accident, and respondent's evaluation of TMI. Characteristics influencing decision to evacuate and to remain in place were studied by different authors (Cutter & Barnes, 1982; Houts et al., 1984). Cutter & Barnes (1982) found, among other aspects, that the proximity to the NPP, the stage in life cycle and the actions of friends and family can influence the decision to evacuate. Prince-Embury (1989) examined the importance of attitudinal and demographic variables in discriminating residents who had moved from those who remained before the restart of the TMI nuclear reactor in 1985. Findings show differences by demographic factors such as age and length of residence in the vicinity.
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Comparison of technologies for deorbiting spacecraft from
Low-Earth-Orbit at end of mission

Comparison of technologies for deorbiting spacecraft from Low-Earth-Orbit at end of mission

Solid arguments to support the superiority of tapes tether as compared with round tethers in deorbiting missions were given in the BETs project. A tape tether is much more robust against space debris and, for equal mass and length, it deorbits faster because the collected current is higher due to the larger perimeter 10 . Since the exposition time of the tether to space debris and its geometry is much more favorable for tapes, they exhibit a cut probability by small debris between one and two orders of magnitude smaller than round tethers. This is an important result that may change the awareness raised by past works on tether survivability 14,18,19 in which the investigators considered long (20km) and round tethers exposed for years to space debris. It is also remarkable that the 4-km round "fat" tether in TIPs mission survived more than 10 years. It suggests that cut probability by small debris of a tape tether with similar length and flying during few months, which is the relevant case for deorbiting mission, should be very low. Hypervelocity impact tests and numerical simulations conducted at the University of Padova have shown that tape tethers are very resistant to space debris impact in the range below 10 cm (non catalogued objects), with a maximum number of predicted failures always less than 0.002 over 1 year mission for a 10km (5km Al+5km inert ) tape tether of width 25.4 mm 20 .
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Medio ambiente y salud

Medio ambiente y salud

It is also apparent that algal blooms potentiate the transmission of cholerae. Electron microscopy has show that algae and the zooplankton that feed upon them provide a natural refuge for V. cholerae, where, under normal conditions, the bacteria exist in a non- cuturable, dormant state. An increase in sea surface temperature, along with high nutrient levels (eutrophication) that stimulate algal growth and de- plete oxygen, can activate the blooms and vibrios. Sea surface temperature in the Bay of Bengal is cor- related with algal blooms and outbreaks of cholera in Bangladesh. 36 Climate variability and change may
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6 Lee mas

«Too many Gatsbys in the fire»: un’occasione mancata?

«Too many Gatsbys in the fire»: un’occasione mancata?

Since the coming of the seventieth year after Fran- cis Scott Fitzgerald’s death allowed to commercially – and legally – take advantage of his works with- out having to pay royalties, publishers big and small flooded bookstores with new translations of his novels. New? Not always. In the more than sixty years since the last Italian version of The Great Gatsby (Fernanda Pivano, Mondadori, 1950) the world gained access to the correct text of the novel, thanks to the efforts of Matthew J. Broccoli; some scholars – among them, Keith Gandal of the City College of New York – have looked at the novel with new eyes and solid scholarship, offering new criti- cal arguments not tainted by prejudice; the theory and practice of translation, finally, evolved and the primacy of the smooth, acceptable (and appropri- ating) translation is now being increasingly eroded (at least by the most righteous) by translations striv- ing to faithfully conform to the text and its cultural specificity, sometimes almost keeping the reader at a distance. Do the new Gatsby’s translations take into account all of this or do they just answer to com- mercial demands? This contribution would aim to be a starting point to the development of a new tra- dition, a new way to address the text that would not respond exclusively to mercantile logic and cat- alog narcissism, but – as it happened with Pivano’s version – would shape new generations of readers, excited but also aware and informed.
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TítuloHorace R  Blank and the origin of rock doughnuts

TítuloHorace R Blank and the origin of rock doughnuts

Rock doughnuts are annular rims situa- ted around rock basins that for varying pe- riods are occupied by pools of water (fig. 1). The term was introduced by Horace Blank (1951) who had noted examples of the lan- dform on granite hills in central Texas, and elsewhere in the United States (see Thor- nbury, 1954: 70). Blank (1898-1984) was at the time a Professor of Geology in the then Agricultural and Mechanical College of Texas, the institution that has evolved into the Texas A. and M. University (Popp 1987). Though primarily a mineralogist, his geolo- gical interests were wide ranging and inclu- ded landscape, for his publications include papers on a landslide, incised meanders, and granite weathering, as well as a pioneering investigation of rock doughnuts. Blank was imaginative in his analysis of the forms, and his investigative method was exemplary, for he proposed various possible explanations of the features he had observed and then considered and tested each against his field evidence.
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27 Lee mas

Spatial data infrastructures for cities in developing countries: lessons from the Bangkok experience

Spatial data infrastructures for cities in developing countries: lessons from the Bangkok experience

These population changes have a profound effect on the demand for services, not only in large urban agglomerations — mega cities — but just as importantly in intermediate and smaller cities. To sus- tain these cities there will be a high demand for resources and services from within the urban and sur- rounding areas and an urgent demand to improve the management and delivery of the services. To meet this demand, systems and procedures will need to be developed that assist in providing the required resources and management in a more efficient and effective manner. Unfortunately, many of the current methods and approaches to managing cities in the developed world have proven only partly successful in developing countries. Different and innovative approaches are required to solve the urgent problems facing Third World cities. However, some of the good old methods may still be relevant because to some extent, today’s conditions of cities in developing countries are similar to cities in developed countries some 50 or 80 years ago but not exactly the same. This paper will evaluate the wide range of spatial information technologies and tools available today which promise considerable potential in supporting these requirements.
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Entrepreneurial teacher training in Europe: an overview of European policies and developments

Entrepreneurial teacher training in Europe: an overview of European policies and developments

Created by teacher Simon Pugh-Jones, the “Writhlington School Orchid Project” grew out of an after-school Gardening Club (still a central part of the Project) that has involved hundreds of students over the more than twenty years it has been running. The responsable teacher has successfully worked various aspects of the Orchid Project‟s horticultural work into the school curriculum (science) for every student at the school. He has also integrated the Project into the subjects of enterprise and technology. Because a single orchid seedpod can contain up to several million seeds, the generative potential of each orchid flower cared for by the students is enormous.The students wholesale their in vitro plants and kits through botanic gardens and the Eden Project, and sell them alongside adult „ex vitro‟ plants directly to the public at shows, such as the Royal Horticultural Society‟s London Orchid Show held in March, at which time they talk about their work and plants with enthusiasm and knowledge.
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Knowledge and use of edible mushrooms in two municipalities of the Sierra Tarahumara, Chihuahua, Mexico

Knowledge and use of edible mushrooms in two municipalities of the Sierra Tarahumara, Chihuahua, Mexico

San Juanito, Arareco and San Rafael claim to wash them in hot water and leave them soaking in water to remove any “hazard” they might carry. They cooked them with garlic in order to test whether they are toxic, using as an indicator a change to black color, indicating that they are poisonous and should not be eaten. This is a common practice throughout the country [50]. However this is not a safe practice as many poisonous mushrooms will react one way or another with the garlic. Also, they admitted that many of the fungi shown in photographs are consid- ered edible elsewhere but they prefer not to eat them for fear, and because they were traditionally considered as bad options. This is a common phenomenon in respect to the utilization of fungi. Moreno Fuentes [25] reported that in another area of the Sierra Tarahumara, the Raramuri did not consume the different species of the genera Boletus, Lactarius, or Russula, which are widely and frequently consumed elsewhere in the country. They prefer to con- sume only Morochike, Sojachi, and Llanero. In the Arareco area, two people mentioned that they use Pleurotus aff. ostreatus as food and call it Floera, “Amuri” or “Amuri Pin”. Some people eat Ramaria and they recognize R. aff. flava and call it “cow tail” (Table 4).
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Terry Turner between Theory and Activism Anthropology as Reality Show and as Co-production : Internal Relations Published by: http:www.sagepublications.com

Terry Turner between Theory and Activism Anthropology as Reality Show and as Co-production : Internal Relations Published by: http:www.sagepublications.com

These issues are as old as the discipline itself, but, as anthropology has grown in size, public influence and institutional power, and recent histori- cal changes have brought changes in its relations to its research subjects and therefore also to itself, the issues have taken on new forms and urgency. One of the things that has happened is that history has caught up with anthropology once again. The unstated but pervasive assumption was that anthropologists came to the peoples they studied as ambassadors from a world of historical progress, a culture moving from a past to a future, to peoples and cultures who had neither a significant historical past nor a future as themselves has been overtaken by events, starting in the late 1960s and early 1970s. Many of the indigenous peoples who once comprised the more or less passive subjects of anthropological research and theorizing became self-conscious historical actors, aggressive partisans of their own cultural and social autonomy. Meanwhile, anthropologists found them- selves challenged by multiculturalist movements and identity politics within their own societies (Turner, 1993, 1999a, 2002a).
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Criticizing and Investigating the Theory of Royal Ring in Parthian and Sassanid Reliefs

Criticizing and Investigating the Theory of Royal Ring in Parthian and Sassanid Reliefs

1) The first issue of a great importance is that it cannot be proved in any of these scenes and under any circumstances that which personality has granted which other personality the ring unless based on the certain presumptions as done by the researchers so far. For instance, the ring has been considered as a godly magnificence and its granting by an earthly figure like the king to an ethereal figure like Ahura Mazda is realized as improbable and contradictory to the beliefs and religiosity of the then time people. If the symbolism of the ring is changed, as a specimen consider it as a ring of victory, then, it will not be conflicting with the religiosity and beliefs of the people and it can be considered as gifted by an earthly figure to the God or a goddess. It is as if the ring symbolizing victory can rule a great many of the scenes and/or it can be gifted by any figure to any other figure if it happens to be changed in its use case. So, in lieu of trying to find a use case for the ring and impose it with a symbolic load before taking measures in line with understanding its real meaning, the ring’s meaning and symbolic load should be determined according to the content of the scene otherwise an endless array of symbolization can be imposed and the scene can be easily justified.
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One too many

One too many

caracterización del personaje con respecto al maquillaje y peinado, sino también se toma en cuenta como punto más importante a rescatar de este fashion film el deseo de Alexia de ser muchas mientras es una sola. Ella fantasea con ser esta mujer inocente, exploradora, amante, rebelde y demás personalidades con tal de salir del estereotipo en el que la tienen, el pedestal en el cual está posando frente a todos. A pesar de esto, en Amor Fati se ve este deseo desde un punto de vista oscuro, más negativo, el sentirse atrapada por no poder ser lo que se quiere ser; mientras que en One Too Many se ve desde un punto de vista más optimista, que es la capacidad de siempre ser alguien nuevo, mejorarse, superarse, pero siempre mantener su esencia buena.
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Research on Teaching in English: Secondary and Higher Education. Where have we been and where are we going?

Research on Teaching in English: Secondary and Higher Education. Where have we been and where are we going?

In the first decade of this new millennium, ELT research and practice has continued to take a turn towards a more specific view on how the use of this global language can be taught and learned by L2/FL learners, especially in European higher education. Many studies within the fields of English for Specific Purposes (ESP) and/or English for Academic Purposes (EAP) have focused on the academic and professional genres, i.e., the types of texts used for written and oral communication. However, with the advent of the digital era and, the pervasiveness of technology, genre studies have taken on other dimensions. The tools for communication or cultural artefacts of the twenty-first century are multimodal, that is, they include numerous modes of representing and communicating meaning (Kress, 2010). Therefore, it is no longer enough to study the written or spoken texts and their underlying meanings. We now need to take into account not only the verbal mode, but also the images, writing, layout, sound, gestures, speech and 3D objects that characterize the diverse mediating tools and resources (Internet, web pages, blogs, learning management systems (LMS), social networks, digital portfolios, linguistic corpuses, etc.) that humans use in present day communication.
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Configuring an RHEL 6 Postfix Email Server

Configuring an RHEL 6 Postfix Email Server

Many system administrators are now using Postfix or Qmail to . Both are faster and easier to configure than Sendmail. For the purposes of this chapter, therefore, we will look at Postfix as an MTA because of its simplicity and popularity. If you would prefer to use Sendmail there are many books that specialize in the subject and that will do the subject much more justice than we can in this chapter.

6 Lee mas

The eviction of indigenous peoples in Tanzania: do the justice system and legal framework protect the land rights of pastoralists?

The eviction of indigenous peoples in Tanzania: do the justice system and legal framework protect the land rights of pastoralists?

Consequently, pastoralist community members are diversifying their livelihood into strategies other than livestock-based economies. Ngorongoro district in Tanzania is a representation of one of the places which has been for a long time a main livelihood strategy for the Maasai community members. Despite that, historically, pastoral land use has co-existed with wildlife, however in recent years the government has decided to forceful evict all Maasai people living around the conservation areas. The eviction process started in 2009 whereby some private companies claimed to own Maasai lands. In August 2017 more than 185 Maasai homesteads were destroyed by Police with the help of rangers from Ngorongoro Conservation Area Authority (NCAA) and Serengeti National Park (SENAPA). This rendered more than 6.800 people homeless, most of their properties were destroyed and more than 2000 livestock were reported missing in Ololosokwan village alone. In Tanzania land tenure insecurity of the Maasai contains land enclosures and displacement from their traditional lands that is initiated by the government, local and foreign businesses 3.
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Predictions and causal estimations are not supported by the same associative structure

Predictions and causal estimations are not supported by the same associative structure

One of the many strategies that have been fol- lowed to distinguish between the associative and the higher order cognitive reasoning accounts of causal learning consists in manipulating the type of question used to request participants’ judge- ments about the perceived degree of relationship between a cue (or cause) and an outcome (or effect). From a strict associative point of view, this manipulation should have no impact on jud- gements. Regardless of the wording of the ques- tion, judgements should be based on the strength of the association between the cue and the outcome that has been learned during the sequence of trials in which both events have or have not co-occurred (see Cobos, Can˜o, Lo´pez, Luque, & Almaraz, 2000). However, if higher order reasoning processes are responsible for par- ticipants’ judgements, manipulating the test ques- tion may have an effect: Different questions might induce participants to think that different statisti- cal indexes should be computed to solve the task efficiently. Empirical research has shown that the precise wording of the test question does have an influence on judgements (Crocker, 1982; De Houwer, Vandorpe, & Beckers, 2007; Gredeba¨ck, Winman, & Juslin, 2000; Matute, Arcediano, & Miller, 1996; Matute, Vegas, & De Marez, 2002; Pinen˜o, Denniston, Beckers, Matute, & Miller, 2005; Vadillo, Miller, & Matute, 2005; White, 2003).
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9th Meeting of the Conference of the Parties to the Convention on Wetlands (Ramsar, Iran, 1971) “ Wetlands and water: supporting life, sustaining livelihoods”

9th Meeting of the Conference of the Parties to the Convention on Wetlands (Ramsar, Iran, 1971) “ Wetlands and water: supporting life, sustaining livelihoods”

26. URGES Contracting Parties and INVITES relevant organizations to use the habitat and species conservation provisions of the Convention to support the introduction and/or continuance of management measures that mitigate the environmental impacts of fishing, including the use of spatial management approaches as appropriate, and ALSO URGES the Ramsar Secretariat to work with other conventions, instruments and organizations concerned with the conservation of biodiversity and the management of natural resources (including FAO at an international and regional level), in order to promote the synergy and alignment of planning and management approaches that benefit the conservation and sustainable management of fisheries resources and recognition of the contribution this makes towards meeting CBD targets, WSSD goals, and Millennium Development Goals (MDGs);
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10 Lee mas

SIMNET: simulation-based exercises for computer net-work curriculum through gamification and augmented reality

SIMNET: simulation-based exercises for computer net-work curriculum through gamification and augmented reality

Some of the advantages of this technology are the following: i) the equipment that students need is a cell phone and a pattern card; ii) the application can be used anywhere and anytime; iii) and can be developing to be used as a standalone application [8]. Therefore, AR has become a popular technology used in educational settings. In this role, AR has also turned into an important focus of research in recent years. One of the most important reasons AR technology is widely accepted because it no longer requires expensive hardware and sophisticated equipment. AR can be defined as a technology that superimposes virtual objects (increased components) in the real world. These vir- tual objects seem to coexist in the same space as real-world objects [9]. Several studies show that AR can improve the teaching and learning experience [10], [11].
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