One for all, all for one---von Neumann, Wald, Rawls, and Pareto

Applications of the maximin criterion extend beyond economics to statistics, computer science, politics, and operations research. However, the maximin criterion---be it von Neumann's, Wald's, or Rawls'---draws fierce criticism due to its extremely pessimistic stance. I propose a novel concept, dubbed the optimin criterion, which is based on (Pareto) optimizing the worst-case payoffs of tacit agreements. The optimin criterion generalizes and unifies results in various fields: It not only coincides with (i) Wald's statistical decision-making criterion when Nature is antagonistic, (ii) the core in cooperative games when the core is nonempty, though it exists even if the core is empty, but it also generalizes (iii) Nash equilibrium in $n$-person constant-sum games, (iv) stable matchings in matching models, and (v) competitive equilibrium in the Arrow-Debreu economy. Moreover, every Nash equilibrium satisfies the optimin criterion in an auxiliary game

Assertive modesty: an economics of intangibles

At the center of our Symposium stand two papers: A Manifesto Concerning the Legal Protection of Computer Programs (Manifesto) and Legal Hybrids: Between the Patent and Copyright Paradigms (Legal Hybrids). Both are stimulating. Both are lengthy. As a result, my primary role is that of a guide: this Comment will summarize the authors\u27 proposals, analyze certain aspects in greater detail, and outline their explicit and implicit methodologies. Part I of the Comment describes the papers\u27 positions and methodologies. Part II highlights some of the papers\u27 many contributions to the literature, and offers some other evaluative observations

Novel Contract Signature based on Key Exchange

A contract signature is a particular form of digital multi-signature that only involves two signers. Contract signing plays a critical role in any business transaction, particularly in situations where the involved parties do not trust each other. One of the most significant concerns in exchange signatures is the fraudulent and unfair exchange, which occurs when one party gets the signature of another party without giving his own signature. In the view of these security concerns, this thesis presents a secure and fair contract signature scheme based on key exchange protocol. The security and protection of the proposed scheme is based on solving hard computational assumptions such as discrete logarithm problem (DLP). The proposed protocol is abuse-free. The proposed scheme targets to have lesser computational overhead and high-security features than existing scheme[1]. The proposed scheme has wide application in real life scenarios, such as in electronic cash system

[[alternative]]The Anonymity Design and Application of Current Signature Schemes

計畫編號：NSC96-2221-E032-026研究期間：200708~200807研究經費：543,000[[abstract]]同時簽章法提供不需要公信第三者的有效公平交換協定做法，為了維 護公平交換者的隱私，同時簽章法也必須提供匿名的服務。然而具有匿名 性的同時簽章法沒有提供驗證的服務，反之不具匿名性的同時簽章法可以 提供驗證的服務，因此在交換簽章時，具有匿名性的同時簽章法無法驗證 交換的簽章。這一點讓攻擊者可以透過傳送大量的交換簽章，耗盡某人的 資源。為了解決這一項問題，計畫的第一年研究課題就是設計同時簽章 法，讓同時簽章法在交換簽章時，就可以同時提供匿名與驗證的服務，同 時提供匿名與驗證的服務也是主要的難題。可轉換環簽章與其它環簽章的 不同點在於匿名的撤消，計畫的第二年研究課題就是為可轉換環簽章，設 計新的匿名撤消，適用於植基因數分解之外難題的環簽章法。目前初步的 構想是利用第一年為同時簽章法設計的匿名與匿名撤消，但主要的困難是 環簽章是可以被任何人匿名地驗證，但是同時簽章法只能被某人所驗證。 有鑑於很難為後付款的小額付款法提供匿名性，計畫的最後一年，就是應 用匿名的同時簽章法，設計後付款的匿名小額付款法。[[sponsorship]]行政院國家科學委員

Reciprocity, Materialism and Welfare: An Evolutionary Model

This paper analyses preference evolution in a bargaining situation. We show that preferences for reciprocity, that sustain a conflict-free outcome, are viable if players have enough information about opponents’ preferences. However, depending on the initial starting point, preference evolution can in general both enhance or reduce subjective and material welfare, relative to the situation where all players have the usual materialistic preferences.Preference evolution; Reciprocity; Altruism; Materialism; Subjective and material eciency; Bargaining; Indirect evolutionary approach

Commodity Trade Stabilization Through International Agreements

We introduce a simple and efficient procedure for the segmentation of rigidly moving objects, imaged under an affine camera model. For this purpose we revisit the theory of "linear combination of views" (LCV), proposed by Ullman and Basri [20], which states that the set of 2d views of an object undergoing 3d rigid transformations, is embedded in a low-dimensional linear subspace that is spanned by a small number of basis views. Our work shows, that one may use this theory for motion segmentation, and cluster the trajectories of 3d objects using only two 2d basis views. We therefore propose a practical motion segmentation method, built around LCV, that is very simple to implement and use, and in addition is very fast, meaning it is well suited for real-time SfM and tracking applications. We have experimented on real image sequences, where we show good segmentation results, comparable to the state-of-the-art in literature. If we also consider computational complexity, our proposed method is one of the best performers in combined speed and accuracy. © 2011. The copyright of this document resides with its authors