Browsing by Subject "Implementation"

Now showing 1 - 17 of 17

Open Access
Environmental education preparation in pre-service teacher programs in Turkey
(2016-05) Güntürkün, Efe
The purpose of this study is to gain insights into how environmental education is implemented into pre-service teacher preparation in Turkey. The format of the courses, their duration, the strategies that are being used, and suggestions to improve these methods were explored. In addition to these data, the missing points in the environmental education in the faculties were analyzed. Two data collection tools were used in this study. One instrument was a questionnaire that was adapted from Ashmann (2010) and the other was an interview designed to ascertain important points of environmental education delivery and to learn suggestions for improving environmental education. The questionnaire was administered to 29 faculty members from institutes that offer teacher education programs in Turkey. The response rate of the questionnaire was 24.14% with seven responses out of 29. The interviews were one with four of the instructors who responded to the questionnaire. One of the most remarkable findings of this study is that environmental education is considered an important subject by instructors who put efforts into their courses. However, the low response rate indicates there is a lack of interest in participating in studies to assess environmental education.
Open Access
Essays on implementability and monotonicity
(2009) Pasin, Pelin
In this thesis we study the implementation problem with regard to the relation between monotonicity and implementability. Recent work in the field has shown that the implementability of a social choice rule strongly depends upon the compatibility between the monotonicity structures of the social choice rule and of the solution concept according to which implementation takes place. Different degrees of monotonicity of the social choice rules and game theoretic solution concepts can be determined via a generalized monotonicity function, strongest of which is called self-monotonicity. In this study, we determine the unique self-monotonicity of the Nash equilibrium concept and show that the monotonicities of a social choice rule are inherited from the unique selfmonotonicity of the Nash equilibrium concept via the mechanisms that implement it. In particular, we show that the essential monotonicity is inherited via the Maskin-Vind type mechanism which is widely used in the characterization results. We also give a new characterization of strong Nash implementable social choice rules via critical profiles. We show that coalitional monotonicity when conjoined with three more conditions is both necessary and sufficient for implementability. Finally we determine a subset of subgame perfect Nash implementable social choice rules that satisfies conditions defined obtained by critical profiles. The results that are obtained in this thesis strongly support the view that implementation theory can be rewritten in terms of monotonicity and that this provides a better understanding of the theory.
Open Access
Explorations on monotonicity in social choice theory
(2007) Doğan, Battal
Due to Maskin (1977), Maskin-monotonicity is known to be a necessary condition for Nash-implementability. Once one classifies social choice rules as the ones which are Maskin-monotonic and those which are not, a natural question one may ask is whether it is possible to further classify the Maskinmonotonic social choice rules according to how strongly monotonic they are. This study utilizes two key notions , namely self-monotonicity and center, which enable us to compare Maskin-monotonic social choice rules among themselves according to the strength of their monotonicities. Moreover, Nashimplementable two-person social choice rules are now characterized via the notion of center, in line with the conjecture that Implementation Theory can be rewritten in terms of monotonicity
Open Access
Generalized second price auction is optimal for discrete types
(Elsevier, 2016) Bayrak, H. I.; Pınar, M. Ç.
We prove that a variant of the second price auction for the sale of a single good through a Bayesian incentive compatible mechanism that maximizes expected revenue of the seller is optimal when the type space is discrete. Moreover, we show that this variant is related to the widely used generalized second price auction mechanism in keyword-auctions for advertising, thus providing a theoretical justification for a practical tool.
Open Access
Implementation in dominant strategy equilibrium
(1995) Kıbrıs, Özgür
A social choice rule is any proposed solution to the problem of collective decision making and it embeds the normative features that can be attached to the mentioned problem. Implementation of social choice rules in dominant strategy equilibrium is the decentralization of the decision power among the agents such that the outcome that is a priori recommended by the social choice rule can be obtained as a dominant strategy equilibrium outcome of the game form which is endowed with the preferences of the individuals. This work has two features. First, it is a survey on the literature on implementation in dominant strategy and its link with the economic theory. Second, it constructs some new relationships among the key terms of the literature. In this framework, it states and proves a slightly generalized version of the Gibbard-Satterthwaite impossibility theorem. Moreover, it states and proves that the cardinality of a singlepeaked domain converges to zero as the number of alternatives increase to infinity.
Open Access
Implementation via code of rights
(2008) Yıldız, Kemal
Implementation of a social choice rule can be thought of as a design of power (re)distribution in the society whose ”equilibrium outcomes” coincide with the alternatives chosen by the social choice rule at any preference profile of the society. In this paper, we introduce a new societal framework for implementation which takes the power distribution in the society, represented by a code of rights, as its point of departure. We examine and identify how implementation via code of rights (referred to as gamma implementation) is related to classical Nash implementation via mechanism. We characterize gamma implementability when the state space on which the rights structure is to be specified consists of the alternatives from which a social choice is to be made. We show that any social choice rule is gamma implementable if it satisfies pivotal oligarchic monotonicity condition that we introduce. Moreover, pivotal oligarchic monotonicity condition combined with Pareto optimality is sufficient for a non-empty valued social choice rule to be gamma implementable. Finally we revisit liberal’s paradox of A.K. Sen, which turns out to fit very well into the gamma implementation framework.
Open Access
Implementation via rights structures
(Academic Press, 2018) Koray, Semih; Yildiz, K.
Implementation of socially desirable alternatives can be thought of as a way to design power distribution in a society such that the equilibrium outcomes coincide with the alternatives chosen at each preference profile. In this paper, we introduce a new institutional framework for implementation, which takes power distribution in a society as its point of departure. We use the notion of a rights structure, introduced by Sertel (2001), to formalize the power distribution in a society. We formulate and characterize implementability via rights structures under different specifications, which require having well-defined convergence dynamics and being consistent with farsighted behavior. We identify how implementation via rights structures is related to implementation via mechanisms. In the presence of at least three agents, we find the class of rights structures, implementability via which is equivalent to Nash and strong Nash implementability. We also introduce a strategic counterpart of implementation via rights structures in terms of deviation-constrained mechanisms.
Open Access
Implementing equal division with an ultimatum threat
(Springer, 2014) Cetemen, E. D.; Karagözoğlu, E.
We modify the payment rule of the standard divide the dollar (DD) game by introducing a second stage and thereby resolve the multiplicity problem and implement equal division of the dollar in equilibrium. In the standard DD game, if the sum of players' demands is less than or equal to a dollar, each player receives what he demanded; if the sum of demands is greater than a dollar, all players receive zero. We modify this second part, which involves a harsh punishment. In the modified game , if the demands are incompatible, then players have one more chance. In particular, they play an ultimatum game to avoid the excess. In the two-player version of this game, there is a unique subgame perfect Nash equilibrium in which players demand (and receive) an equal share of the dollar. We also provide an -player extension of our mechanism. Finally, the mechanism we propose eliminates not only all pure strategy equilibria involving unequal divisions of the dollar, but also all equilibria where players mix over different demands in the first stage.
Open Access
Multistage optical interconnection architectures with the least possible growth of system size
(Optical Society of America, 1993) Özaktaş, Haldun M.; Mendlovic, D.
Multistage interconnection architectures can provide an arbitrary pattern of one-to-one connections between N input and N output channels. We show that bitonic multistage architectures, such as the Banyan architecture, result in the fundamentally least possible growth of system size with increasing N.
Open Access
A novel characterization of nash-implementable social choice rules via neutrality
(2020-07) Mammadov, Aghaheybat
In this thesis, we study Nash implementability of social choice rules in relation with the neutrality notion. Several works in the literature provide a characterization of Nash-implementable social choice rules. However, they do not explicitly show the degree of neutrality property in the Nash equilibrium concept which is also existing in Nash-implementable rules. In this study, we deﬁne a weak version of the neutrality condition critical neutrality which is associated with the critical domain of a social choice rule. The critical neutrality notion when conjoined with Maskin monotonicity turns out to be equivalent to Nash implementability. Moreover, we propose an algorithm to obtain a maximal domain of preference proﬁles on which a speciﬁed social choice rule is Nash-implementable, by utilizing critical neutrality as a tool. The main result of the thesis is in support of the view that implementability on the full domain of preference proﬁles is highly related with implementability on the critical domain in Nash equilibrium and possibly, in other solution concepts.
Open Access
Optimal allocation with costly inspection and discrete types under ambiguity
(Taylor & Francis, 2017) Bayrak, H. I.; Güler, K.; Pınar, M. Ç.
We consider the following problem: a principal has a good to allocate among a collection of agents who attach a private value to receiving the good. The principal, instead of using monetary transfers (i.e. charging the agents) to allocate the good, can check the truthfulness of the agents' value declaration at a cost. Under the assumption that the agents' valuations are drawn from a discrete set of values at random, we characterize the class of optimal Bayesian mechanisms which are symmetric, direct and maximizing the expected value of assigning the good to the principal minus the cost of verification using such standard finite-dimensional optimization tools as linear programming and submodular functions, thus extending the work of [R.V. Vohra, Optimization and mechanism design, Math. Program. 134 (2012), pp. 283–303]. Our results are discrete-type analogs of those of [E. Ben-Porath, E. Dekel, and B.L. LipmanBen-Porath, Optimal allocation with costly verification, Amer. Econ. Rev. 104 (2014), pp. 3779–3813]. When the distribution of valuations is not known but can be one of a set of distributions (the case referred to as ambiguity), we compute a robust allocation mechanism by maximizing the worst-case expected value of the principal in two cases amenable to solution with two suitable assumptions on the set of distributions.
Open Access
Party implementation
(2009) Apakan, Hasan Tahsin
In this study party implementation concept is introduced. Party implementation is an extension of classical implementation allowing different parties to have group-specific choice rules. Members of a party are assumed to act cooperatively according to a common preference. In this context, a choice rule is said to be party implementable if it is robust to co-operative manipulation. In this thesis some necessity and sufficiency results for party implementation are proven. In particular, it is shown that under some restrictions if the societies choice rule is party implementable, an alternative that is chosen by any group should also be chosen by the society. Conversely, it is shown that if the collective choice can be represented by the union of different groups’ choice, then the social choice rule should be party implementable.
Open Access
Portfolio implementation at Turkish university preparatory schools, and teachers' perceptions of portfolios and problems experienced with portfolio use
(2009) Kılıç, Emine
This study seeks to investigate portfolio implementation at Turkish university preparatory schools and the reported aims of portfolio use as targeted by these schools. The study further examines teachers‟ perceptions of portfolio use, specifically, the problems they experience with portfolio use, possible sources of these problems and their suggestions on how portfolio use can be improved. The study was conducted in two phases. In the first phase, data on portfolio use and aims of its use were collected through a questionnaire administered at seven university preparatory schools. In the second phase, data on teachers‟ perceptions were gathered through a second questionnaire administered to 126 teachers at five of the seven preparatory schools. The results reached in the first phase of the study revealed that portfolios are mainly used for the writing component of the preparatory programs. The analyses of the data also revealed that certain key features of portfolios, such as student participation in the selection of portfolio content, self assessment, and student reflection, are not generally included in portfolios at preparatory programs. Regarding the aims of portfolio use targeted by schools, the results indicate that in order to achieve the intended aims, the missing key elements of portfolios should be included. The results reached in the second phase of the study indicate that teachers perceive portfolios as an appropriate tool for assessment purposes. When the results regarding teachers‟ experiences with portfolio use are examined, the outcomes indicate that the problems experienced with portfolio use are in large part felt to be related to students‟ attitudes towards portfolios, which are themselves caused by students‟ study habits and previous educational backgrounds. It was also revealed that problems related to portfolio entries and institutional practices create some challenges in portfolio implementation at schools.
Open Access
Prototype implementation of dynavote e-voting protocol
(ACI, 2009-06) Çetinkaya, O.; Koc, M. Levent
Voting is regarded as one of the most effective methods for individuals to express their opinions on a given topic. Electronic voting (eVoting) refers to the use of computers or computerised voting equipments to cast ballots in an election. eVoting performed over Internet can be universally accepted in the upcoming years due to the fact that Internet plays key roles in people's lives. The DynaVote eVoting protocol claims that it is practical over a network since it does not use complex algorithms and has no physical assumptions such as untappable channels, whereas fulfilling core voting requirements such as privacy, accuracy, uncoercibility and individual verifiability. Software development requires considerable amount of time and money. Therefore, in order to utilise all resources, the prototype implementation gains more importance as it gives quick feedbacks about the practicality of the system. This paper presents a prototype implementation of DynaVote eVoting protocol over the Internet. Since DynaVote relies on PVID scheme, which is an unlinkable pseudo identity mechanism, the prototype includes implementation of PVID scheme component as well. The main outcome of this study is to prove that DynaVote protocol over Internet is practical and applicable in real life and to illustrate that PVID scheme provides unlinkability. This study also contributes some improvements in DynaVote e-voting protocol. Furthermore, this paper analyses how the prototype fulfils some electronic voting system requirements such as efficiency, transparency and mobility.
Open Access
Subgame perfect implementation of men-optimal matchings
(2017-07) Teoman, Ece
In this study, we explore monotonicities and implementability of di erent matching rules. We nd a self-monotonicity of the stable rule and an h-monotonicity for the men-optimal rule, which does not satisfy Maskin-monotonicity. We then o er a sequential matching mechanism that implements the men-optimal rule in subgame perfect equilibrium, when there is no other matching that weakly Pareto-dominates the men-optimal matching for men. In our mechanism, women propose to men in an arbitrary hierarchy order, and each man either accepts or rejects the proposals he receives, where accepting means permanent matching with the proposing woman.
Open Access
Synthesis of general linear systems with repeated filtering in consecutive fractional Fourier domains
(Optical Society of America, 1998) Erden, M. F.; Özaktaş, Haldun M.
The optical and digital implementations of general linear systems are costly. Through several examples we show that either exact realizations or useful approximations of these systems may be implemented in the form of repeated-filtering operations in consecutive fractional Fourier domains. These implementations are much cheaper than direct implementations of general linear systems. Thus we may significantly decrease the implementation costs of general linear systems with little or no decrease in performance by synthesizing them with the proposed repeated-filtering method. (C) 1998 Optical Society of America.
Open Access
Two essays in social choice theory
(2000) Kaya, Ayça
Solution concepts which implement only monotonic social choice rules are characterized in terms of a new notion of monotonicity pertaining to solution concepts. For any given class G of mechanisms, it turns out that a solution concept a implements only monotonic social choice rules via mechanisms in G if and only if a is G-monotonic. Moreover, with each solution concept a, we associate a class G^ of mechanisms such that each a-implementable onto social choice function which takes on at least three different values is dictatorial if and only if a is Go-monotonic. Oligarchic social choice rules are characterized by the conjunction of unanimity and a monotonicity condition, oligarchic monotonicity, which is stronger than Maskin monotonicity. Given an oligarchic social choice rule, the coalition acting as the oligarchy turns out to be the minimal set T of agents such that the social choice mle is Maskin monotonic when the restriction of each profile to T is considered. Finally, the solution concepts which implement only oligarchic social choice rules are characterized in terms of oligarchic monotonicity modified for solution concepts.